# Study of Grid-Connected PV System for a Low Voltage Distribution System: A Case Study of Cambodia

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Materials and Methods

#### 2.1. Developed Algorithms

#### 2.1.1. Shortest Path

#### 2.1.2. Repeated Phase ABC

^{st}algorithm is implemented [26]. This proposed algorithm finds the total active power at each electrical pole in the first step. Then, the phase sequence ABC is repeated for every three connected poles to balance the loads. The RPABC algorithm is illustrated in Figure 3.

#### 2.1.3. First Fit Bin Packing

^{nd}algorithm named first-fit bin-packing (FFBP) is applied [27]. The problem with FFBP is to package all items in a defined number of bins while minimizing the difference in the total weight of each bin. In this article, the power consumption (i.e., P and Q) of households and the phase (A-B-C) of the system are items and the bins, respectively.

#### 2.1.4. Mixed-Integer Quadratic Programming

- Arborescence

- Phase connection of load

#### 2.2. Economic Analysis by HOMER Pro

#### 2.3. A Case Study

#### 2.3.1. Studied Site and Normalized Curve

^{st}bus. The total active power is about 43 kW with a power factor of 0.95. A normalized daily load curve with a 1 h time step is taken from local measurements in a village. Figure 4 shows the geography of the test system of low voltage distribution.

#### 2.3.2. Solar Radiation

^{2}/day.

#### 2.3.3. Electricity Tariff in Cambodia

#### 2.4. Grid-Connected PV System

#### 2.4.1. Simulation Model

#### 2.4.2. System Components and Parameter

## 3. Simulation Results and Discussion

#### 3.1. Optimal Distribution System

#### 3.1.1. Radial Distribution System Topology

^{2}is used for the mainline and 4 mm

^{2}from the main feeder to each energy meter which is currently implemented in Cambodia. Figure 8 provides the optimal radial topology which is performed with SP-MIQP.

#### 3.1.2. Voltage Profiles and MV/LV Distribution Transformer

^{2}) which is currently used in Cambodia. Moreover, the 3rd algorithm is quite good in voltage and required active power at the MV/LV distribution transformer (see Table 4) compared to others.

#### 3.1.3. Performance of Three Proposed Algorithms

#### 3.1.4. Economic Evaluation with Different Electricity Tariffs

## 4. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## References

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**Figure 5.**(

**a**) Setup of load profile measurement for the simulation and (

**b**) normalized daily load curve for the simulation [26].

**Table 1.**Regulation for utilities and electricity tariff for consumers with meter at a low voltage of the licensee’s transformer.

Items | Tariff Option | ||
---|---|---|---|

Option 1 | Option 2 | Option 3 | |

Description | General tariff | Time of use | PV consumer |

Capacity charge | - | 5.80 USD/kW/Month | 5.80 USD/kW/Month |

Energy charge (7 a.m. to 9 p.m.) | - | 0.1640 USD/kWh | - |

Energy charge (9 p.m. to 7 a.m.) | - | 0.13696 | - |

Tariff | 0.17232 USD/kWh | - | 0.1640 USD/kWh |

Items | Description | ||
---|---|---|---|

PV System | Inverter | Grid | |

Capacity (kW) | 1 | 1 | - |

Capital cost (USD) | 600 | 300 | - |

Replacement cost (USD) | 600 | 300 | - |

O&M cost (USD/year) | 10 | 10 | - |

Lifetime (year) | 30 | 15 | - |

Degrading factor (%) | 80 | - | - |

Efficiency (%) | - | 95 | - |

Contract capacity (kVA) | - | - | 50 |

Algorithms | Total Active Power P(kW) | ||
---|---|---|---|

A-Phase | B-Phase | C-Phase | |

1st Algorithm | 14.048 | 10.035 | 18.917 |

2nd Algorithm | 13.975 | 14.294 | 14.731 |

3rd Algorithm | 13.923 | 15.127 | 13.950 |

Items | Algorithms | ||
---|---|---|---|

1st Algorithm | 2nd Algorithm | 3rd Algorithm | |

Annual energy used (MWh) | 198.57 | 197.02 | 196.94 |

MV/LV Required (kW) | 46.60 | 45.92 | 45.89 |

Maximal power loss (kW) | 3.60 | 2.92 | 2.89 |

Maximal current (A) | 91.87 | 70.16 | 71.78 |

Minimal voltage (pu) | 0.9216 | 0.9395 | 0.9394 |

OPEX per year (KUSD) | 36.239 | 35.956 | 35.940 |

Indicators | Description | ||
---|---|---|---|

Option 1 | Option 2 | Option 3 | |

PV (kW) | - | - | 22.5 |

Inverter (kW) | - | - | 15.8 |

NPC (kUSD) | 360.359 | 353.137 | 345.813 |

LCOE (USD/kWh) | 0.1723 | 0.1689 | 0.1654 |

Operating cost (kUSD/year) | 33.938 | 33.258 | 30.850 |

Initial capital cost (kUSD) | - | - | 18.24 |

Renewable energy fraction (%) | - | - | 15.8 |

CO_{2} Emissions (Mg/year) | 124.47 | 124.47 | 104.86 |

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**MDPI and ACS Style**

Vai, V.; Eng, S.
Study of Grid-Connected PV System for a Low Voltage Distribution System: A Case Study of Cambodia. *Energies* **2022**, *15*, 5003.
https://doi.org/10.3390/en15145003

**AMA Style**

Vai V, Eng S.
Study of Grid-Connected PV System for a Low Voltage Distribution System: A Case Study of Cambodia. *Energies*. 2022; 15(14):5003.
https://doi.org/10.3390/en15145003

**Chicago/Turabian Style**

Vai, Vannak, and Samphors Eng.
2022. "Study of Grid-Connected PV System for a Low Voltage Distribution System: A Case Study of Cambodia" *Energies* 15, no. 14: 5003.
https://doi.org/10.3390/en15145003