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Adaptive Observer-Based Grid-Synchronization and Sequence Extraction Techniques for Renewable Energy Systems: A Comparative Analysis^{ †}

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*Applied Sciences*: Invited Papers in Electrical, Electronics and Communications Engineering Section)

## Abstract

**:**

## 1. Introduction

## 2. Problem Formulation

## 3. Overview of the Selected Techniques

#### 3.1. Global Adaptive Observer (GAO)

#### 3.1.1. Development of Phase Voltage Dynamical Model

#### 3.1.2. Observer Design

#### 3.2. Gain Normalized Adaptive Observer

#### 3.3. SOGI-Type Adaptive Observer

#### 3.3.1. Quadrature Signal-Based Dynamic Model Development

#### 3.3.2. Observer Design

## 4. Results and Discussions

#### 4.1. Simulation Results

- Test-I: Balanced to unbalanced grid,
- Test-II: Voltage sag,
- Test-III: Phase step change, and
- Test-IV: DC offset.

#### 4.2. Experimental Results

#### 4.2.1. Unbalanced Grid

#### 4.2.2. Unbalanced and Distorted Grid

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

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Characteristics | GAO | GNAO | SAO |
---|---|---|---|

Dynamic Performance | Very Fast | Very Fast | Very Fast |

Voltage Sag Sensitivity | High | Low | Low |

Harmonic Disturbance | Good | Very Good | Very Good |

DC Offset Rejection | Good | Very Good | Very Good |

Computational Complexity | Medium | High | Medium |

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**MDPI and ACS Style**

Ahmed, H.; Benbouzid, M.
Adaptive Observer-Based Grid-Synchronization and Sequence Extraction Techniques for Renewable Energy Systems: A Comparative Analysis. *Appl. Sci.* **2021**, *11*, 653.
https://doi.org/10.3390/app11020653

**AMA Style**

Ahmed H, Benbouzid M.
Adaptive Observer-Based Grid-Synchronization and Sequence Extraction Techniques for Renewable Energy Systems: A Comparative Analysis. *Applied Sciences*. 2021; 11(2):653.
https://doi.org/10.3390/app11020653

**Chicago/Turabian Style**

Ahmed, Hafiz, and Mohamed Benbouzid.
2021. "Adaptive Observer-Based Grid-Synchronization and Sequence Extraction Techniques for Renewable Energy Systems: A Comparative Analysis" *Applied Sciences* 11, no. 2: 653.
https://doi.org/10.3390/app11020653