Editorial

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7 pages, 229 KiB

Open AccessEditorial

Applications of Power Electronics

by

Frede Blaabjerg

,

Tomislav Dragicevic

and

Pooya Davari

Electronics 2019, 8(4), 465; https://doi.org/10.3390/electronics8040465 - 25 Apr 2019

Cited by 9 | Viewed by 8824

Abstract

Power electronics technology is still an emerging technology, and it has found its way into many applications, from renewable energy generation (i [...] Full article

(This article belongs to the Special Issue Applications of Power Electronics)

Research

Jump to: Editorial, Review, Other

15 pages, 5394 KiB

Open AccessArticle

Generalized Cascaded Symmetric and Level Doubling Multilevel Converter Topology with Reduced THD for Photovoltaic Applications

by

Karthikeyan D

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Vijayakumar K

and

Jagabar Sathik M

Electronics 2019, 8(2), 161; https://doi.org/10.3390/electronics8020161 - 01 Feb 2019

Cited by 16 | Viewed by 3200

Abstract

In this paper, two different converter topologies for a basic new switched capacitor diode converter with a reduced number of power electronics components, suitable for grid connected photovoltaic applications were proposed. The two different structures of switched diode multilevel converter proposed were: (i) [...] Read more.

In this paper, two different converter topologies for a basic new switched capacitor diode converter with a reduced number of power electronics components, suitable for grid connected photovoltaic applications were proposed. The two different structures of switched diode multilevel converter proposed were: (i) cascaded switched diode and (ii) cascaded switched diode with doubling circuit. The switched-diode multilevel converter was compared with other recent converters. In addition, a new dc offset nearest level modulation technique was proposed. This proposed dc offset technique offers low voltage total harmonic distortion (THD) and high RMS output voltage. The proposed modulation technique was compared with conventional nearest level modulation (NLM) and modified NLM control techniques. The performance of the proposed dc offset modulation technique was implemented using a FPGA Spartan 3E controller and tested with a novel switched capacitor-diode multilevel converter. However, to prove the authenticity of the switched-diode multilevel converter and modulation technique, a laboratory-based prototype model for 7-level and 13-level converters was developed. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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10 pages, 3475 KiB

Open AccessArticle

Analysis of Equivalent Inductance of Three-Phase Induction Motors in the Switching Frequency Range

by

Milan Srndovic

,

Rastko Fišer

and

Gabriele Grandi

Electronics 2019, 8(2), 120; https://doi.org/10.3390/electronics8020120 - 22 Jan 2019

Cited by 6 | Viewed by 4892

Abstract

The equivalent inductance of three-phase induction motors is experimentally investigated in this paper, with particular reference to the frequency range from 1 kHz to 20 kHz, typical for the switching frequency in inverter-fed electrical drives. The equivalent inductance is a basic parameter when [...] Read more.

The equivalent inductance of three-phase induction motors is experimentally investigated in this paper, with particular reference to the frequency range from 1 kHz to 20 kHz, typical for the switching frequency in inverter-fed electrical drives. The equivalent inductance is a basic parameter when determining the inverter-motor current distortion introduced by switching modulation, such as rms of current ripple, peak-to-peak current ripple amplitude, total harmonic distortion (THD), and synthesis of the optimal PWM strategy to minimize the THD itself. In case of squirrel-cage rotors, the experimental evidence shows that the equivalent inductance cannot be considered constant in the frequency range up to 20 kHz, and it considerably differs from the value measured at 50 Hz. This frequency-dependent behaviour can be justified mainly by the skin effect in rotor bars affecting the rotor leakage inductance in the considered frequency range. Experimental results are presented for a set of squirrel-cage induction motors with different rated power and one wound-rotor motor in order to emphasize the aforesaid phenomenon. The measurements were carried out by a three-phase sinusoidal generator with the maximum operating frequency of 5 kHz and a voltage source inverter operating in the six-step mode with the frequency up to 20 kHz. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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20 pages, 11715 KiB

Open AccessFeature PaperArticle

Design, Simulation and Hardware Implementation of Shunt Hybrid Compensator Using Synchronous Rotating Reference Frame (SRRF)-Based Control Technique

by

R. Balasubramanian

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K. Parkavikathirvelu

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R. Sankaran

and

Rengarajan Amirtharajan

Electronics 2019, 8(1), 42; https://doi.org/10.3390/electronics8010042 - 01 Jan 2019

Cited by 12 | Viewed by 4528

Abstract

This paper deals with the design, simulation, and implementation of shunt hybrid compensator to maintain the power quality in three-phase distribution networks feeding different types balanced and unbalanced nonlinear loads. The configuration of the compensator consists of a selective harmonic elimination passive filter, [...] Read more.

This paper deals with the design, simulation, and implementation of shunt hybrid compensator to maintain the power quality in three-phase distribution networks feeding different types balanced and unbalanced nonlinear loads. The configuration of the compensator consists of a selective harmonic elimination passive filter, a series-connected conventional six-pulse IGBT inverter, acting as the active filter terminated with a DC link capacitor. The theory and modelling of the compensator based on current harmonic components at the load end and their decomposition in d-q axis frame of reference are utilized in the reference current generation algorithm. Accordingly, the source current waveform is made to follow the reference current waveform using a high-frequency, carrier-based controller. Further, this inner current control loop is supported by a slower outer voltage control loop for sustaining desirable DC link voltage. Performance of the compensator is evaluated through MATLAB simulation covering different types of loads and reduction of harmonic currents and THD at the supply side along with excellent regulation of DC link voltage are confirmed. The performance of a hybrid compensator designed and fabricated using the above principles is evaluated and corroborated with the simulation results. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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18 pages, 8166 KiB

Open AccessArticle

Design of A Novel Line Start Synchronous Motor Rotor

by

Berkan Zöhra

,

Mehmet Akar

and

Mustafa Eker

Electronics 2019, 8(1), 25; https://doi.org/10.3390/electronics8010025 - 26 Dec 2018

Cited by 22 | Viewed by 5167

Abstract

Line start permanent magnet synchronous motors (LS-PMSM) are preferred more and more in industrial applications, because they can start on their own and because of their high efficiency. In this study, a new LS-PMSM rotor typology is suggested, which is modelled using surface [...] Read more.

Line start permanent magnet synchronous motors (LS-PMSM) are preferred more and more in industrial applications, because they can start on their own and because of their high efficiency. In this study, a new LS-PMSM rotor typology is suggested, which is modelled using surface mount permanent magnets, in which two different slot types have been used together. The rotor of an asynchronous motor on the industrial market in the IE2 efficiency segment has been remodeled in the study, resulting in an increase in motor efficiency from 85% to 91.8%. A finite elements software was used for determining motor design and performance, in addition to analytical methods. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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16 pages, 4421 KiB

Open AccessFeature PaperArticle

Automatic Fault Diagnostic System for Induction Motors under Transient Regime Optimized with Expert Systems

by

Jordi Burriel-Valencia

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Ruben Puche-Panadero

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Javier Martinez-Roman

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Angel Sapena-Bano

,

Manuel Pineda-Sanchez

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Juan Perez-Cruz

and

Martin Riera-Guasp

Electronics 2019, 8(1), 6; https://doi.org/10.3390/electronics8010006 - 21 Dec 2018

Cited by 33 | Viewed by 3938

Abstract

Induction machines (IMs) power most modern industrial processes (induction motors) and generate an increasing portion of our electricity (doubly fed induction generators). A continuous monitoring of the machine’s condition can identify faults at an early stage, and it can avoid costly, unexpected shutdowns [...] Read more.

Induction machines (IMs) power most modern industrial processes (induction motors) and generate an increasing portion of our electricity (doubly fed induction generators). A continuous monitoring of the machine’s condition can identify faults at an early stage, and it can avoid costly, unexpected shutdowns of production processes, with economic losses well beyond the cost of the machine itself. Machine current signature analysis (MCSA), has become a prominent technique for condition-based maintenance, because, in its basic approach, it is non-invasive, requires just a current sensor, and can process the current signal using a standard fast Fourier transform (FFT). Nevertheless, the industrial application of MCSA requires well-trained maintenance personnel, able to interpret the current spectra and to avoid false diagnostics that can appear due to electrical noise in harsh industrial environments. This task faces increasing difficulties, especially when dealing with machines that work under non-stationary conditions, such as wind generators under variable wind regime, or motors fed from variable speed drives. In these cases, the resulting spectra are no longer simple one-dimensional plots in the time domain; instead, they become two-dimensional images in the joint time-frequency domain, requiring highly specialized personnel to evaluate the machine condition. To alleviate these problems, supporting the maintenance staff in their decision process, and simplifying the correct use of fault diagnosis systems, expert systems based on neural networks have been proposed for automatic fault diagnosis. However, all these systems, up to the best knowledge of the authors, operate under steady-state conditions, and are not applicable in a transient regime. To solve this problem, this paper presents an automatic system for generating optimized expert diagnostic systems for fault detection when the machine works under transient conditions. The proposed method is first theoretically introduced, and then it is applied to the experimental diagnosis of broken bars in a commercial cage induction motor. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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14 pages, 1939 KiB

Open AccessArticle

Small Signal Stability of a Balanced Three-Phase AC Microgrid Using Harmonic Linearization: Parametric-Based Analysis

by

Atta Ur Rahman

,

Irtaza Syed

and

Mukhtar Ullah

Electronics 2019, 8(1), 12; https://doi.org/10.3390/electronics8010012 - 21 Dec 2018

Cited by 4 | Viewed by 3066

Abstract

The growth of power-electronic-based components is inescapable in future distribution grids (DGs). The introduction of these non-linear components poses many challenges, not only in terms of power quality, but also in terms of stability. These challenges become more acute when active loads are [...] Read more.

The growth of power-electronic-based components is inescapable in future distribution grids (DGs). The introduction of these non-linear components poses many challenges, not only in terms of power quality, but also in terms of stability. These challenges become more acute when active loads are behaving as generators and power is flowing in reverse direction. The frequency-domain-based impedance modeling methods are preferred for small signal stability analysis (SSSA) of DGs involving such non-linear components. The harmonic linearization method can be used for impedance estimation, and afterwards, the Nyquist stability criterion can be used for stability analysis. In this paper, a parametric-based stability analysis of grid-connected active loads at the point of common coupling (PCC) is done by changing the parallel clustering distance and size of active loads. The results verify a positive impact on the stability of increasing parallel clustering and distance from the PCC and a negative impact of increasing the size of individual active loads. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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12 pages, 4150 KiB

Open AccessArticle

Reliability of Boost PFC Converters with Improved EMI Filters

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Electronics 2018, 7(12), 413; https://doi.org/10.3390/electronics7120413 - 08 Dec 2018

Cited by 10 | Viewed by 6974

Abstract

The switching device in a power converter can produce very serious electromagnetic interference (EMI). In order to solve this problem and the associated reliability and stability issues, this article aimed to analyze and model the boost power factor correction (PFC) converter according to [...] Read more.

The switching device in a power converter can produce very serious electromagnetic interference (EMI). In order to solve this problem and the associated reliability and stability issues, this article aimed to analyze and model the boost power factor correction (PFC) converter according to the EMI conduction path. The sources of common-mode (CM) and differential-mode (DM) noise of the boost PFC converter were analyzed, and the DM and CM equivalent circuits were deduced. Furthermore, high-frequency modeling of the common-mode inductor was developed using a precise model, and the EMI filter was designed. According to the Class B standard for EMI testing, it is better to restrain the EMI noise in the frequency range (150 kHz to 30 MHz) of the EMI conducted disturbance test. Using this method, a 2.4-kW PFC motor driving supply was designed, and the experimental results validate the analysis. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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18 pages, 4569 KiB

Open AccessArticle

A Novel Composite Equalizer Based on an Additional Cell for Series-Connected Lithium-Ion Cells

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Electronics 2018, 7(12), 366; https://doi.org/10.3390/electronics7120366 - 01 Dec 2018

Cited by 10 | Viewed by 3095

Abstract

Cell inconsistency can lead to poor performance and safety hazards. Therefore, cell equalizer is essentially required to prevent the series-connected cells from overcharging, undercharging, and overdischarging. Among current equalization schemes, passive equalizer has a continuously wasting energy with low equalization efficiency, and active [...] Read more.

Cell inconsistency can lead to poor performance and safety hazards. Therefore, cell equalizer is essentially required to prevent the series-connected cells from overcharging, undercharging, and overdischarging. Among current equalization schemes, passive equalizer has a continuously wasting energy with low equalization efficiency, and active equalizer has high cost with complex circuit structure. In this study, a novel composite equalizer based on an additional cell with low complexity is presented. This method combines a passive equalizer and an active equalizer. Firstly, the configuration and circuit of our proposed composite equalizer are introduced, and the equalization principle is analyzed. On this basis, the control strategy and algorithm of the composite equalizer are further proposed. Finally, the composite equalizer is verified through simulation and experiment in various cases. The study results show that this method improves both the consistency level and the available capacity of the battery pack. Moreover, our proposed equalizer can overcome the shortcomings of commonly used equalizer and combining the advantages of different equalizer to maximize the equalization efficiency with a simpler equalizer structure. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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15 pages, 825 KiB

Open AccessArticle

Robust DC-Link Voltage Tracking Controller with Variable Control Gain for Permanent Magnet Synchronous Generators

by

Seok-Kyoon Kim

and

Kyo-Beum Lee

Electronics 2018, 7(11), 339; https://doi.org/10.3390/electronics7110339 - 21 Nov 2018

Cited by 3 | Viewed by 2840

Abstract

This study develops a robust DC-link voltage tracking controller with variable control gain for permanent magnet synchronous generators. The first feature is to suggest an auto-tuning algorithm to drive the control gain to update the closed-loop cut-off frequency. The second one is to [...] Read more.

This study develops a robust DC-link voltage tracking controller with variable control gain for permanent magnet synchronous generators. The first feature is to suggest an auto-tuning algorithm to drive the control gain to update the closed-loop cut-off frequency. The second one is to prove that the proposed controller incorporating auto-tuner and disturbance observer (DOB) coerces the closed-loop system to achieve the desired voltage tracking behavior, exponentially, with the steady-state rejection property. The control performance is demonstrated by emulating a wind-turbine power system using the powerSIM (PSIM) software. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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17 pages, 4367 KiB

Open AccessArticle

An All-Region State-of-Charge Estimator Based on Global Particle Swarm Optimization and Improved Extended Kalman Filter for Lithium-Ion Batteries

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Electronics 2018, 7(11), 321; https://doi.org/10.3390/electronics7110321 - 14 Nov 2018

Cited by 19 | Viewed by 3819

Abstract

In this paper, a novel model parameter identification method and a state-of-charge (SOC) estimator for lithium-ion batteries (LIBs) are proposed to improve the global accuracy of SOC estimation in the all SOC range (0–100%). Firstly, a subregion optimization method based on particle swarm [...] Read more.

In this paper, a novel model parameter identification method and a state-of-charge (SOC) estimator for lithium-ion batteries (LIBs) are proposed to improve the global accuracy of SOC estimation in the all SOC range (0–100%). Firstly, a subregion optimization method based on particle swarm optimization is developed to find the optimal model parameters of LIBs in each subregion, and the optimal number of subregions is investigated from the perspective of accuracy and computation time. Then, to solve the problem of a low accuracy of SOC estimation caused by large model error in the low SOC range, an improved extended Kalman filter (IEKF) algorithm with variable noise covariance is proposed. Finally, the effectiveness of the proposed methods are verified by experiments on two kinds of batteries under three working cycles, and case studies show that the proposed IEKF has better accuracy and robustness than the traditional extended Kalman filter (EKF) in the all SOC range. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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20 pages, 12656 KiB

Open AccessArticle

A Novel Synchronization Technique for Wireless Power Transfer Systems

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Electronics 2018, 7(11), 319; https://doi.org/10.3390/electronics7110319 - 13 Nov 2018

Cited by 9 | Viewed by 4932

Abstract

Recently, wireless power transfer (WPT) systems with active receivers have been proposed for conduction loss reduction, bidirectional power transfer and efficiency improvement. However, the synchronization of WPT systems is complex in nature with the selection of high operating frequencies. Without proper synchronization, power [...] Read more.

Recently, wireless power transfer (WPT) systems with active receivers have been proposed for conduction loss reduction, bidirectional power transfer and efficiency improvement. However, the synchronization of WPT systems is complex in nature with the selection of high operating frequencies. Without proper synchronization, power oscillations appear and the system can become unstable. In this paper, a detailed analysis of different WPT systems is presented and the essence of the synchronization technique is derived as being composed of two functions: independent frequency locking and reference phase calibration. The voltage across the receiver-side compensation capacitor is divided and utilized for frequency locking, whereas the reference phase calibration is realized through software code. The proposed method is effective and easy to implement, with a lower overall cost due to its simplicity. The technique can work effectively at high frequency and withstand large variations of operating frequency, load and mutual inductance. In addition, it can address the synchronization problem of multiple active receiver WPT systems with and without cross coupling among the receiving coils. Theoretical analysis and experimental results validate the proposed technique. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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21 pages, 9742 KiB

Open AccessFeature PaperArticle

EMI Filter Design for a Single-stage Bidirectional and Isolated AC–DC Matrix Converter

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Electronics 2018, 7(11), 318; https://doi.org/10.3390/electronics7110318 - 12 Nov 2018

Cited by 20 | Viewed by 10209

Abstract

This paper describes the design of an electromagnetic interference (EMI) filter for the high-frequency link matrix converter (HFLMC). The proposed method aims to systematize the design process for pre-compliance with CISPR 11 Class B standard in the frequency range 150 kHz to 30 [...] Read more.

This paper describes the design of an electromagnetic interference (EMI) filter for the high-frequency link matrix converter (HFLMC). The proposed method aims to systematize the design process for pre-compliance with CISPR 11 Class B standard in the frequency range 150 kHz to 30 MHz. This approach can be extended to other current source converters which allows time-savings during the project of the filter. Conducted emissions are estimated through extended simulation and take into account the effect of the measurement apparatus. Differential-mode (DM) and common-mode (CM) filtering stages are projected separately and then integrated in a synergistic way in a single PCB to reduce volume and weight. A prototype of the filter was constructed and tested in the laboratory. Experimental results with the characterization of the insertion losses following the CISPR 17 standard are provided. The attenuation capability of the filter was demonstrated in the final part of the paper. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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15 pages, 6174 KiB

Open AccessArticle

Open Circuit Fault Diagnosis and Fault Tolerance of Three-Phase Bridgeless Rectifier

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Electronics 2018, 7(11), 291; https://doi.org/10.3390/electronics7110291 - 01 Nov 2018

Cited by 13 | Viewed by 4050

Abstract

Bridgeless rectifiers are widely used in many applications due to a unity power factor, lower conduction loss and high efficiency, which does not need bidirectional energy transmission. In this case, the potential failures are threatening the reliability of these converters in critical applications [...] Read more.

Bridgeless rectifiers are widely used in many applications due to a unity power factor, lower conduction loss and high efficiency, which does not need bidirectional energy transmission. In this case, the potential failures are threatening the reliability of these converters in critical applications such as power supply and electric motor driver. In this paper, open circuit fault is analyzed, taking a three-phase bridgeless as an example. Interference on both the input and output side are considered. Then, the fault diagnosis method including detection and location, and fault tolerance through additional switches are proposed. At last, simulation and experiments based on the hardware in loop technology are used to validate the feasibility of fault diagnosis and fault tolerance methodology. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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23 pages, 7155 KiB

Open AccessArticle

FPGA Implementation of a Three-Level Boost Converter-fed Seven-Level DC-Link Cascade H-Bridge inverter for Photovoltaic Applications

by

Nagaraja Rao Sulake

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Ashok Kumar Devarasetty Venkata

and

Sai Babu Choppavarapu

Electronics 2018, 7(11), 282; https://doi.org/10.3390/electronics7110282 - 29 Oct 2018

Cited by 23 | Viewed by 4045

Abstract

This paper presents an optimized single-phase three-level boost DC-link cascade H-bridge multilevel inverter (TLBDCLCHB MLI) system to generate a seven-level stepped output voltage waveform for photovoltaic (PV) applications. The proposed TLBDCLCHB MLI system is obtained by integrating a three-level boost converter (TLBC) with [...] Read more.

This paper presents an optimized single-phase three-level boost DC-link cascade H-bridge multilevel inverter (TLBDCLCHB MLI) system to generate a seven-level stepped output voltage waveform for photovoltaic (PV) applications. The proposed TLBDCLCHB MLI system is obtained by integrating a three-level boost converter (TLBC) with a seven-level DC-link cascade H-bridge (DCLCHB) inverter. It consists of a TLBC, level generation unit (LGU) and phase sequence generation unit (PSGU). When compared with traditional boost converter-fed multilevel inverter systems, the proposed TLBDCLCHB MLI system requires a single DC source, fewer power switches and gate drivers. Reduction in the switch count and number of DC sources makes the system cost effective and requires a smaller installation area. Pulse generation for the power switches of an LGU in a DCLCHB inverter is accomplished by providing proper conducting angles that are generated by optimized conducting angle determination (CAD) techniques. In this paper two CAD techniques i.e., equal-phase CAD (EPCAD) and step pulse wave CAD (SPWCAD) techniques are proposed to evaluate the performance of the proposed system in terms of the total harmonic distortion (THD) and the quality of the stepped output voltage waveform. The proposed system has been modeled and simulated using MATLAB/SIMULINK software. Results are presented and discussed. Also, a prototype model of a single-phase TLBDCLCHB MLI system is developed using a field-programmable gate array (FPGA)-based pulse generation with a resistive load and its performance is analyzed for various operating conditions. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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16 pages, 7956 KiB

Open AccessArticle

A Novel Single-switch Phase Controlled Wireless Power Transfer System

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Electronics 2018, 7(11), 281; https://doi.org/10.3390/electronics7110281 - 29 Oct 2018

Cited by 2 | Viewed by 3732

Abstract

Battery charging is a fundamental application of Wireless Power Transfer (WPT) systems that requires effective implementation of Constant Current (CC) and Constant Voltage (CV) power conduction modes. DC-DC converters used in WPT systems utilize large inductors and capacitors that increase the size and [...] Read more.

Battery charging is a fundamental application of Wireless Power Transfer (WPT) systems that requires effective implementation of Constant Current (CC) and Constant Voltage (CV) power conduction modes. DC-DC converters used in WPT systems utilize large inductors and capacitors that increase the size and volume of the system in addition to causing higher DC losses. This work proposes a novel single-switch active rectifier for phase controlled WPT systems that is smaller in volume and weight as compared to conventional WPT topologies. The proposed method simplifies the control scheme using improved Digital Phase Control (DPC) and Analog Phase Control (APC) to realize the CC and CV power transfer modes. Furthermore, it prevents forward voltage losses in Silicon Carbide (SiC) switches and shoot through states with improved switching patterns. Simulation studies and experimental results are added to verify the effectiveness of the proposed methodology. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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14 pages, 4676 KiB

Open AccessArticle

Comparative Analysis of Two and Four Current Loops for Vector Controlled Dual-Three Phase Permanent Magnet Synchronous Motor

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Electronics 2018, 7(11), 269; https://doi.org/10.3390/electronics7110269 - 23 Oct 2018

Cited by 6 | Viewed by 3345

Abstract

Dual three-phase (DTP) permanent magnet synchronous motors (PMSMs) are specialized machines which are commonly used for high power density applications. These machines offer the merits of high efficiency, high torque density, and superior supervisor fault tolerant capability compared to conventional three-phase AC-machines. However, [...] Read more.

Dual three-phase (DTP) permanent magnet synchronous motors (PMSMs) are specialized machines which are commonly used for high power density applications. These machines offer the merits of high efficiency, high torque density, and superior supervisor fault tolerant capability compared to conventional three-phase AC-machines. However, the electrical structure of such machines is very complicated, and as such, control becomes challenging. In conventional vector controlled DTP-PMSMs drives, the components of the dq-subspace are associated with electromechanical energy conversion, and two currents, i.e., I_d and I_q belonging to this subspace, are used in feedback-loops for control. Such orthodox control methods can cause some anomalies e.g., the voltage source inverter’s (VSI) dead time effect and other nonlinear factors, and can induce large harmonics. These glitches can be greatly alleviated by the introduction of the two-extra current loops to directly control the currents in Z₁Z₂-subspace in order to suppress the insertion of harmonics. In this paper, two approaches—one with two-current loops and other with four-current loops—for vector controlled DTP-PMSMs are investigated with the aid of different MATLAB-based simulations. Furthermore, in the paper, the influence of additional current loops is quantified using simulation-based results. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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16 pages, 4953 KiB

Open AccessArticle

Performance Improvement for PMSM DTC System through Composite Active Vectors Modulation

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Tianqing Yuan

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Dazhi Wang

Electronics 2018, 7(10), 263; https://doi.org/10.3390/electronics7100263 - 22 Oct 2018

Cited by 10 | Viewed by 2920

Abstract

In this paper, a novel direct torque control (DTC) scheme based on composite active vectors modulation (CVM) is proposed for permanent magnet synchronous motor (PMSM). The precondition of the accurate compensations of torque error and flux linkage error is that the errors can [...] Read more.

In this paper, a novel direct torque control (DTC) scheme based on composite active vectors modulation (CVM) is proposed for permanent magnet synchronous motor (PMSM). The precondition of the accurate compensations of torque error and flux linkage error is that the errors can be compensated fully during the entire control period. Therefore, the compensational effects of torque error and flux linkage error in different operating conditions of the PMSM are analyzed firstly, and then, the operating conditions of the PMSM are divided into three cases according to the error compensational effects. To bring the novel composite active vectors modulation strategy smoothly, the effect factors are used to represent the error compensational effects provided by the applied active vectors. The error compensational effects supplied by single active vector or synthetic voltage vector are analyzed while the PMSM is operated in three different operating conditions. The effectiveness of the proposed CVM-DTC is verified through the experimental results on a 100-W PMSM drive system. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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15 pages, 4925 KiB

Open AccessArticle

A Fixed-Frequency Sliding-Mode Controller for Fourth-Order Class-D Amplifier

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Electronics 2018, 7(10), 261; https://doi.org/10.3390/electronics7100261 - 19 Oct 2018

Cited by 6 | Viewed by 4444

Abstract

Since the parasitic voltage ringing and switching power losses limit the operation of active devices at elevated frequencies; therefore, a higher-order inductor-capacitor (LC) filter is commonly used, which offers extended attenuation above the cutoff frequency and thus, improves the total harmonic distortion (THD) [...] Read more.

Since the parasitic voltage ringing and switching power losses limit the operation of active devices at elevated frequencies; therefore, a higher-order inductor-capacitor (LC) filter is commonly used, which offers extended attenuation above the cutoff frequency and thus, improves the total harmonic distortion (THD) of the amplifier. This paper applies the concept of integral sliding-mode control to a fourth-order class-D amplifier. Two fixed-frequency double integral sliding-mode (FFDISM) controllers are proposed, where one uses the inductor current while the other involves the capacitor current feedback. Their equivalent control equations are derived, but from the realization viewpoint, the controller using the capacitor current feedback is advantageous and, therefore, is selected for final implementation. The performance of the proposed FFDISM controller for fourth-order GaN class-D amplifier is confirmed using simulation and experimental results. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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19 pages, 3949 KiB

Open AccessArticle

Simulation Model of a 2-kW IPT Charger with Phase-Shift Control: Validation through the Tuning of the Coupling Factor

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Javier Vázquez

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Pedro Roncero-Sánchez

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Alfonso Parreño Torres

Electronics 2018, 7(10), 255; https://doi.org/10.3390/electronics7100255 - 16 Oct 2018

Cited by 9 | Viewed by 3304 | Correction

Abstract

When applied to road vehicle electrification, inductive power transfer (IPT) technology has the potential to boost the transition from combustion engines to electric motors powered by a battery pack. This work focuses on the validation of a PSpice circuit model developed as a [...] Read more.

When applied to road vehicle electrification, inductive power transfer (IPT) technology has the potential to boost the transition from combustion engines to electric motors powered by a battery pack. This work focuses on the validation of a PSpice circuit model developed as a replica of a 2-kW IPT prototype with series-series compensation operating at 18.65 kHz. The laboratory prototype has the three stages commonly found in an IPT system: an inverter, controlled by the phase-shift technique, a coil coupling and a load. Simulations were run with the circuit model for three different distances between the two coils of the inductive coupling, all of which are of interest for practical chargers: 125, 150 and 175 mm. The validation approach was based on tuning the magnetic coupling factor for each distance and a set of ten load resistances, until the best match between the simulated and the experimental peak currents supplied by the inverter was found in each case. The coupling factors obtained from the simulation work are in good agreement with their experimental counterparts for the three distances, provided the duty cycle of the inverter output voltage is not too small. The circuit model developed is, therefore, able to reproduce the behavior of the laboratory prototype with sufficient accuracy over a wide range of distances between coils and loading conditions. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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25 pages, 7481 KiB

Open AccessArticle

Active EMI Reduction Using Chaotic Modulation in a Buck Converter with Relaxed Output LC Filter

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Electronics 2018, 7(10), 254; https://doi.org/10.3390/electronics7100254 - 16 Oct 2018

Cited by 18 | Viewed by 7358

Abstract

DC-DC buck converters are widely used in portable applications because of their high power efficiency. However, their inherent fast switching releases electromagnetic emissions, making them prominent sources of electromagnetic interference (EMI). This paper proposes a voltage-controlled buck converter that reduces EMI by using [...] Read more.

DC-DC buck converters are widely used in portable applications because of their high power efficiency. However, their inherent fast switching releases electromagnetic emissions, making them prominent sources of electromagnetic interference (EMI). This paper proposes a voltage-controlled buck converter that reduces EMI by using a chaotic pulse-width modulation (PWM) technique based on a chaotic triangular ramp generator. The chaotic triangular ramp generator is constructed from a simple on-chip chaotic circuit linked with a symmetrically triangular ramp circuit. The proposed converter can thus operate in the chaotic mode reducing the EMI without requiring any EMI filters. Additionally, using the triangular ramp signal can relax the requirement for a large LC output filter in chaotic mode. The effectiveness of the proposed scheme was experimentally verified with a chaotic triangular ramp generator embedded in a voltage-mode controller buck converter using a 0.18 µm Complementary Metal Oxide Semiconductor (CMOS) process. The measurement results from a prototype showed that the EMI improvement from the proposed scheme is approximately 14.53 dB at the fundamental switching frequency with respect to the standard fixed-frequency PWM reference case. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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18 pages, 5224 KiB

Open AccessArticle

4T Analog MOS Control-High Voltage High Frequency (HVHF) Plasma Switching Power Supply for Water Purification in Industrial Applications

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Electronics 2018, 7(10), 245; https://doi.org/10.3390/electronics7100245 - 11 Oct 2018

Cited by 10 | Viewed by 10452

Abstract

High-power plasma power supply is very useful for many industrial and medical applications. Plasma is generated artificially in the laboratory or industry by applying the electric or magnetic field. In this manuscript, we presented the simple 4T analog MOS control high voltage high [...] Read more.

High-power plasma power supply is very useful for many industrial and medical applications. Plasma is generated artificially in the laboratory or industry by applying the electric or magnetic field. In this manuscript, we presented the simple 4T analog MOS control high voltage high frequency inverter circuit as a plasma power supply using modulation index technique. The presented plasma power supply operated at 25 kHz frequency and 10 kV peak to peak voltage. It generates a 0 V to 10 kV controllable electric field. The generated electric field is applied and produces plasma, which can be used for many industrial applications. A 10 kV to 5 kW plasma power supply has been practically developed based on the proposed topology and experimentally tested and, additionally, excellent output power conversion efficiency is achieved. From these results, the 4T analog MOS control high voltage high frequency (HVHF) plasma switching power supply is verified. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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26 pages, 4607 KiB

Open AccessArticle

SHIL and DHIL Simulations of Nonlinear Control Methods Applied for Power Converters Using Embedded Systems

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Electronics 2018, 7(10), 241; https://doi.org/10.3390/electronics7100241 - 06 Oct 2018

Cited by 19 | Viewed by 3664

Abstract

In this work, a new real-time Simulation method is designed for nonlinear control techniques applied to power converters. We propose two different implementations: in the first one (Single Hardware in The Loop: SHIL), both model and control laws are inserted in the same [...] Read more.

In this work, a new real-time Simulation method is designed for nonlinear control techniques applied to power converters. We propose two different implementations: in the first one (Single Hardware in The Loop: SHIL), both model and control laws are inserted in the same Digital Signal Processor (DSP), and in the second approach (Double Hardware in The Loop: DHIL), the equations are loaded in different embedded systems. With this methodology, linear and nonlinear control techniques can be designed and compared in a quick and cheap real-time realization of the proposed systems, ideal for both students and engineers who are interested in learning and validating converters performance. The methodology can be applied to buck, boost, buck-boost, flyback, SEPIC and 3-phase AC-DC boost converters showing that the new and high performance embedded systems can evaluate distinct nonlinear controllers. The approach is done using matlab-simulink over commodity Texas Instruments Digital Signal Processors (TI-DSPs). The main purpose is to demonstrate the feasibility of proposed real-time implementations without using expensive HIL systems such as Opal-RT and Typhoon-HL. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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14 pages, 5432 KiB

Open AccessFeature PaperArticle

Improving Performance of Three-Phase Slim DC-Link Drives Utilizing Virtual Positive Impedance-Based Active Damping Control

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Electronics 2018, 7(10), 234; https://doi.org/10.3390/electronics7100234 - 04 Oct 2018

Cited by 2 | Viewed by 3968

Abstract

In this paper, a virtual positive impedance (VPI) based active damping control for a slim DC-link motor drive with 24 section space vector pulse width modulation (SVPWM) is proposed. Utilizing the proposed control and modulation strategy can improve the input of current total [...] Read more.

In this paper, a virtual positive impedance (VPI) based active damping control for a slim DC-link motor drive with 24 section space vector pulse width modulation (SVPWM) is proposed. Utilizing the proposed control and modulation strategy can improve the input of current total harmonic distortion (THD) while maintaining the cogging torque of the motor. The proposed system is expected to reduce the front-end current THD according to international standards, as per IEC 61000 and IEEE-519. It is also expected to achieve lower cost, longer lifetime, and fewer losses. A permanent magnet synchronous motor (PMSM) is fed by the inverter, which adopts the 24 section SVPWM technique. The VPI based active damping control for the slim DC-link drive with/without the 24 section SVPWM are compared to confirm the performance of the proposed method. The simulation results based on MATLAB are provided to validate the proposed control strategy. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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12 pages, 2260 KiB

Open AccessArticle

Exploring the Limits of Floating-Point Resolution for Hardware-In-the-Loop Implemented with FPGAs

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Alberto Sanchez

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Elías Todorovich

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Angel De Castro

Electronics 2018, 7(10), 219; https://doi.org/10.3390/electronics7100219 - 27 Sep 2018

Cited by 13 | Viewed by 3104

Abstract

As the performance of digital devices is improving, Hardware-In-the-Loop (HIL) techniques are being increasingly used. HIL systems are frequently implemented using FPGAs (Field Programmable Gate Array) as they allow faster calculations and therefore smaller simulation steps. As the simulation step is reduced, the [...] Read more.

As the performance of digital devices is improving, Hardware-In-the-Loop (HIL) techniques are being increasingly used. HIL systems are frequently implemented using FPGAs (Field Programmable Gate Array) as they allow faster calculations and therefore smaller simulation steps. As the simulation step is reduced, the incremental values for the state variables are reduced proportionally, increasing the difference between the current value of the state variable and its increments. This difference can lead to numerical resolution issues when both magnitudes cannot be stored simultaneously in the state variable. FPGA-based HIL systems generally use 32-bit floating-point due to hardware and timing restrictions but they may suffer from these resolution problems. This paper explores the limits of 32-bit floating-point arithmetics in the context of hardware-in-the-loop systems, and how a larger format can be used to avoid resolution problems. The consequences in terms of hardware resources and running frequency are also explored. Although the conclusions reached in this work can be applied to any digital device, they can be directly used in the field of FPGAs, where the designer can easily use custom floating-point arithmetics. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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21 pages, 2972 KiB

Open AccessArticle

Optimized Design of Modular Multilevel DC De-Icer for High Voltage Transmission Lines

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Electronics 2018, 7(9), 204; https://doi.org/10.3390/electronics7090204 - 17 Sep 2018

Cited by 8 | Viewed by 3660

Abstract

Ice covering on overhead transmission lines would cause damage to transmission system and long-term power outage. Among various de-icing devices, a modular multilevel converter based direct-current (DC)de-icer (MMC-DDI) is recognized as a promising solution due to its excellent technical performance. Its principle feasibility [...] Read more.

Ice covering on overhead transmission lines would cause damage to transmission system and long-term power outage. Among various de-icing devices, a modular multilevel converter based direct-current (DC)de-icer (MMC-DDI) is recognized as a promising solution due to its excellent technical performance. Its principle feasibility has been well studied, but only a small amount of literature discusses its economy or hardware optimization. To fill this gap, this paper presents a quantitative analysis and calculation on the converter characteristics of MMC-DDI. It reveals that, for a given DC de-icing requirement, the converter rating varies greatly with its alternating-current (AC) -side voltage, and it sometimes far exceeds the melting power. To reduce converter rating and improve its economy, an optimized configuration is proposed in which a proper transformer should be configured on the input AC-side of converter under certain conditions. This configuration is verified in an MMC-DDI for a 500 kV transmission line as a case study. The result shows, in the case of outputting the same de-icing characteristics, the optimized converter is reduced from 151 MVA to 68 MVA, and the total cost of the MMC-DDI system is reduced by 48%. This conclusion is conducive to the design optimization of multilevel DC de-icer and then to its engineering application. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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12 pages, 2895 KiB

Open AccessArticle

Line Frequency Instability of One-Cycle-Controlled Boost Power Factor Correction Converter

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Electronics 2018, 7(9), 203; https://doi.org/10.3390/electronics7090203 - 17 Sep 2018

Cited by 8 | Viewed by 4488

Abstract

Power Factor Correction (PFC) converters are widely used in engineering. A classical PFC control circuit employs two complicated feedback control loops and a multiplier, while the One-Cycle-Controlled (OCC) PFC converter has a simple control circuit. In OCC PFC converters, the voltage loop is [...] Read more.

Power Factor Correction (PFC) converters are widely used in engineering. A classical PFC control circuit employs two complicated feedback control loops and a multiplier, while the One-Cycle-Controlled (OCC) PFC converter has a simple control circuit. In OCC PFC converters, the voltage loop is implemented with a PID control and the multiplier is not needed. Although linear theory is used in designing the OCC PFC converter control circuit, it cannot be used in predicting non-linear phenomena in the converter. In this paper, a non-linear model of the OCC PFC Boost converter is proposed based on the double averaging method. The line frequency instability of the converter is predicted by studying the DC component, the first harmonic component and the second harmonic component of the main circuit and the control circuit. The effect of the input voltage and the output capacitance on the stability of the converter is studied. The correctness of the proposed model is verified with numerical simulations and experimental measurements. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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15 pages, 1751 KiB

Open AccessArticle

Improved Step Load Response of a Dual-Active-Bridge DC–DC Converter

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Electronics 2018, 7(9), 185; https://doi.org/10.3390/electronics7090185 - 09 Sep 2018

Cited by 8 | Viewed by 3750

Abstract

This paper proposes a fast load transient control for a bidirectional dual-active-bridge (DAB) DC/DC converter. It is capable of maintaining voltage–time balance during a step load change process so that no overshoot current and DC offset current exist. The transient control has been [...] Read more.

This paper proposes a fast load transient control for a bidirectional dual-active-bridge (DAB) DC/DC converter. It is capable of maintaining voltage–time balance during a step load change process so that no overshoot current and DC offset current exist. The transient control has been applied for all possible transition cases and the calculation of intermediate switching angles referring to the fixed reference points is independent from the converter parameters and the instantaneous current. The results have been validated by extended experimental tests. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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14 pages, 5823 KiB

Open AccessArticle

Performance Evaluation of a Semi-Dual-Active-Bridge with PPWM Plus SPS Control

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Ming Lu

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Xiaodong Li

Electronics 2018, 7(9), 184; https://doi.org/10.3390/electronics7090184 - 09 Sep 2018

Cited by 5 | Viewed by 3645

Abstract

In this paper, a semi-dual-active-bridge (S-DAB) DC/DC converter with primary pulse-width modulation plus secondary phase-shifted (PPWM + SPS) control for boost conversion is analyzed in detail. Under the new control scheme, all effective operation modes are identified at first. Then, the working principle, [...] Read more.

In this paper, a semi-dual-active-bridge (S-DAB) DC/DC converter with primary pulse-width modulation plus secondary phase-shifted (PPWM + SPS) control for boost conversion is analyzed in detail. Under the new control scheme, all effective operation modes are identified at first. Then, the working principle, switching behaviour, and operation range in each mode are discussed. Compared with conventional secondary phase-shifted control, PPWM + SPS control with two controllable phase-shift angles can extend the zero-voltage switching (ZVS) range and enhance control flexibility. In addition, an effective control route is also given that can make the converter achieve at the global minimum root-mean-square (RMS) current across the whole power range and avoid the voltage ringing on the transformer secondary-side at a light load. Finally, a 200 W prototype circuit is built and tested to verify correctness and effectiveness of theoretical results. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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21 pages, 8477 KiB

Open AccessArticle

Wireless Power Transfer for Battery Powering System

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Electronics 2018, 7(9), 178; https://doi.org/10.3390/electronics7090178 - 07 Sep 2018

Cited by 12 | Viewed by 3907

Abstract

The LCL topology (formed by an LC tank with a transmitting coil) is extensively utilized in wireless power transfer (WPT) systems with the features of a constant resonant current and ability to disconnect load abruptly. However, it requires high input voltage, which limits [...] Read more.

The LCL topology (formed by an LC tank with a transmitting coil) is extensively utilized in wireless power transfer (WPT) systems with the features of a constant resonant current and ability to disconnect load abruptly. However, it requires high input voltage, which limits its utilization in battery powering scenarios (12~24 V). A current-fed inverter (CFI) is applied to the LCL-S (a compensation capacitor in series with the receiving coil) WPT systems to boost the input voltage, thereby getting a higher resonant current in the transmitting side (Tx). To facilitate the voltage regulation in the receiving side (Rx), a semi-active bridge (SAB) is introduced into the system, which further boosts the output voltage by a lower frequency switching at different duty ratios. Rigorous mathematical analysis of the proposed system is carried out and design guidelines are subsequently derived. Moreover, a power loss reduction is realized by zero voltage switch (ZVS) of the four switches in the Tx which are deduced and presented. Simulations and experiments are added to verify the proposed system. Consequently, a 93.3% system efficiency (DC-to-DC efficiency) is obtained using the proposed topology. Optimization techniques for a higher efficiency are included in this study. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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16 pages, 3717 KiB

Open AccessArticle

New Fault-Tolerant Control Strategy of Five-Phase Induction Motor with Four-Phase and Three-Phase Modes of Operation

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Sonali Chetan Rangari

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Hiralal Murlidhar Suryawanshi

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Mohan Renge

Electronics 2018, 7(9), 159; https://doi.org/10.3390/electronics7090159 - 23 Aug 2018

Cited by 22 | Viewed by 4865

Abstract

The developed torque with minimum oscillations is one of the difficulties faced when designing drive systems. High ripple torque contents result in fluctuations and acoustic noise that impact the life of a drive system. A multiphase machine can offer a better alternative to [...] Read more.

The developed torque with minimum oscillations is one of the difficulties faced when designing drive systems. High ripple torque contents result in fluctuations and acoustic noise that impact the life of a drive system. A multiphase machine can offer a better alternative to a conventional three-phase machine in faulty situations by reducing the number of interruptions in industrial operation. This paper proposes a unique fault-tolerant control strategy for a five-phase induction motor. The paper considers a variable-voltage, variable-frequency control five-phase induction motor in one- and two-phase open circuit faults. The four-phase and three-phase operation modes for these faults are utilized with a modified voltage reference signal. The suggested remedial strategy is the method for compensating a faulty open phase of the machine through a modified reference signal. A modified voltage reference signal can be efficiently executed by a carrier-based pulse width modulation (PWM) system. A test bench for the execution of the fault-tolerant control strategy of the motor drive system is presented in detail along with the experimental results. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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17 pages, 3733 KiB

Open AccessArticle

Energy Management and Switching Control of PHEV Charging Stations in a Hybrid Smart Micro-Grid System

by

Tariq Kamal

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Murat Karabacak

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Syed Zulqadar Hassan

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Luis M. Fernández-Ramírez

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Muhammad Hussnain Riaz

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Muhammad Tanveer Riaz

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Muhammad Abbas Khan

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Laiq Khan

Electronics 2018, 7(9), 156; https://doi.org/10.3390/electronics7090156 - 22 Aug 2018

Cited by 28 | Viewed by 6139

Abstract

In this study, the energy management and switching control of plug-in hybrid electric vehicles (PHEVs) in a hybrid smart micro-grid system was designed. The charging station in this research consists of real market PHEVs of different companies with different sizes. The rate of [...] Read more.

In this study, the energy management and switching control of plug-in hybrid electric vehicles (PHEVs) in a hybrid smart micro-grid system was designed. The charging station in this research consists of real market PHEVs of different companies with different sizes. The rate of charging of PHEVs is managed via switching control to receive maximum benefits from renewable energy sources and reduce the consumption of electricity from the grid. To support the optimum utilization of sustainable power, charging time and network stability, seven scenarios were developed for different interaction among the proposed micro-grid system and PHEVs. The proposed hybrid smart micro-grid system consists of three renewable energy sources: photovoltaic (PV) array controlled via an intelligent fuzzy control maximum power point subsystem, a fuel cell stack and a microturbine set controlled by proportional integral differential/proportional integral subsystems. A hybrid energy storage system (super-capacitor, battery storage bank and hydrogen) and residential load are also included in the proposed architecture. The hybrid smart micro-grid system is checked in terms of voltage regulation, frequency deviation and total harmonic distortion (THD). It was found that these are in limits according to the international standards. The simulations verify the feasibility of the proposed system and fulfill the requirement of vehicle-to-grid and grid-to-vehicle operations in a smart grid environment. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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24 pages, 7390 KiB

Open AccessArticle

On-Line Application of SHEM by Particle Swarm Optimization to Grid-Connected, Three-Phase, Two-Level VSCs with Variable DC Link Voltage

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Umut Güvengir

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Işık Çadırcı

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Muammer Ermiş

Electronics 2018, 7(8), 151; https://doi.org/10.3390/electronics7080151 - 20 Aug 2018

Cited by 4 | Viewed by 4667

Abstract

This paper is devoted to an otablen-line application of the selective harmonic elimination method (SHEM) to three-phase, two-level, grid-connected voltage source converters (VSCs) by particle swarm optimization (PSO). In such systems, active power can be controlled by the phase shift angle, and reactive [...] Read more.

This paper is devoted to an otablen-line application of the selective harmonic elimination method (SHEM) to three-phase, two-level, grid-connected voltage source converters (VSCs) by particle swarm optimization (PSO). In such systems, active power can be controlled by the phase shift angle, and reactive power by the modulation index, against variations in the direct current (DC) link voltage. Some selected, low-odd-order harmonic components in the line-to-neutral output voltage waveforms are eliminated by calculating the SHEM angle set continuously through the developed PSO algorithm on field-programmable gate array (FPGA)-based computing hardware as the modulation index is varied. The use of powerful computing hardware permits the elimination of all harmonics up to 50th. The cost function of the developed PSO algorithm is formulated by using an optimum number of particles to obtain a global optimum solution with a small fitness value in each half-cycle of the grid voltage and then updating the SHEM angle set at the beginning of the next full-cycle. Since the convergence of the solution to a global minimum point depends upon the use of correct initial values especially for a large number of SHEM angles, a generalized initialization procedure is also described in the paper. Theoretical results are verified initially using hardware co-simulation. They are also tested using a small scale photovoltaic (PV) supply prototype developed specifically for this purpose. It is demonstrated that the 5th, 7th, 11th, 13th, 17th, and 19th sidekick harmonics are eliminated by on-line calculation of seven SHEM angles through the developed PSO algorithm on a moderately powerful XEM6010-LX150, USB-2.0-integrated FPGA module. All control and protection actions and the calculation of SHEM angles are achieved by a single FPGA chip and its peripherals within the FPGA board. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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21 pages, 3209 KiB

Open AccessArticle

Series Active Filter Design Based on Asymmetric Hybrid Modular Multilevel Converter for Traction System

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Muhammad Ali

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Muhammad Mansoor Khan

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Electronics 2018, 7(8), 134; https://doi.org/10.3390/electronics7080134 - 01 Aug 2018

Cited by 4 | Viewed by 3792

Abstract

This paper presents a comparative analysis of a new topology based on an asymmetric hybrid modular multilevel converter (AHMMC) with recently proposed multilevel converter topologies. The analysis is based on various parameters for medium voltage-high power electric traction system. Among recently proposed topologies, [...] Read more.

This paper presents a comparative analysis of a new topology based on an asymmetric hybrid modular multilevel converter (AHMMC) with recently proposed multilevel converter topologies. The analysis is based on various parameters for medium voltage-high power electric traction system. Among recently proposed topologies, few converters have been analysed through simulation results. In addition, the study investigates AHMMC converter which is a cascade arrangement of H-bridge with five-level cascaded converter module (FCCM) in more detail. The key features of the proposed AHMMC includes: reduced switch losses by minimizing the switching frequency as well as the components count, and improved power factor with minimum harmonic distortion. Extensive simulation results and low voltage laboratory prototype validates the working principle of the proposed converter topology. Furthermore, the paper concludes with the comparison factors evaluation of the discussed converter topologies for medium voltage traction applications. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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19 pages, 8118 KiB

Open AccessArticle

A Reduced Switch AC-AC Converter with the Application of D-STATCOM and Induction Motor Drive

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Chaitanya Jibhakate

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Madhuri Chaudhari

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Mohan Renge

Electronics 2018, 7(7), 110; https://doi.org/10.3390/electronics7070110 - 10 Jul 2018

Cited by 5 | Viewed by 3966

Abstract

In this paper, a reduced switch AC-DC-AC converter is used as a distribution static compensator (DSTATCOM) and induction motor drive. The AC-DC-AC nine switch converter (NSC) is a reduced switch topology of conventional 12-switch back to back converter. With a 25% reduced switch [...] Read more.

In this paper, a reduced switch AC-DC-AC converter is used as a distribution static compensator (DSTATCOM) and induction motor drive. The AC-DC-AC nine switch converter (NSC) is a reduced switch topology of conventional 12-switch back to back converter. With a 25% reduced switch count, NSC has lower losses when operated at constant frequency mode compared to twelve switch converter (TSC). The idea is to operate NSC input terminal as an active front-end rectifier to mimic synchronous generator (SG) operation. The induction motor is connected at the output of the NSC for irrigation application where no speed regulation is required. In distribution generation (DG), a large capacitor bank is used to deliver required reactive power. This may lead to over-voltage at the point of common coupling (PCC) when the load is turned off. To manage reactive power transfer at PCC, a control scheme is developed for NSC such that it can absorb or deliver reactive power with induction motor drive. Similar to SG, V-curve and inverted V-curve is plotted. The simulation and hardware results prove the feasibility of the proposed system. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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24 pages, 10993 KiB

Open AccessArticle

A Variable Speed Pumped Storage System Based on Droop-Fed Vector Control Strategy for Grid Frequency and AC-Bus Voltage Stability

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Girmaw Teshager Bitew

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Minxiao Han

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Sifrash Amogne Mekonnen

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Patrobers Simiyu

Electronics 2018, 7(7), 108; https://doi.org/10.3390/electronics7070108 - 07 Jul 2018

Cited by 9 | Viewed by 4129

Abstract

Harnessing wind energy is the most rapidly growing amongst renewable energy sources. However, because of its intermittency in nature, wind power results in unfavorable influences on power system control, operation and stability. The voltage sag and flicker and grid frequency fluctuation are significant [...] Read more.

Harnessing wind energy is the most rapidly growing amongst renewable energy sources. However, because of its intermittency in nature, wind power results in unfavorable influences on power system control, operation and stability. The voltage sag and flicker and grid frequency fluctuation are significant in this regard. To minimize the effect of wind power fluctuations and other contingencies on the grid frequency and AC-bus voltage, this paper presents a droop-fed vector control strategy based variable speed pumped storage (VSPS) system comprising the doubly fed induction machine. Modelling of the system is undertaken based on a phasor model technique. The case study is made by considering the droop-controlled VSPS plant in a grid containing conventional synchronous machines for hydropower and thermal power plants and an induction machine wind farm. The performance is validated and analyzed using a MATLAB/Simulink platform. The proposed droop-fed control model is compared with the conventional control strategy (without being droop-fed) and tested to wind power fluctuations, start-up transients, load variations and three-phase fault. The results show that the droop-fed vector control strategy of the VSPS plant achieves better dynamic and steady state controlling responses for grid frequency and AC-bus voltage in the power system than the conventional vector control scheme during wind power fluctuations and contingencies. Full article

(This article belongs to the Special Issue Applications of Power Electronics)

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