Comparison of Reactive Power Control Techniques for Solar PV Inverters to Mitigate Voltage Rise in Low-Voltage Grids

The greater integration of solar photovoltaic (PV) systems into low-voltage (LV) distribution networks has posed new challenges for the operation of power systems. The violation of voltage limits attributed to reverse power flow has been recognized as one of the significant consequences of high PV penetration. Thus, the reactive power control of PV inverters has emerged as a viable solution for localized voltage regulation. This paper presents a detailed study on a typical Malaysian LV distribution network to demonstrate the effectiveness of different reactive power control techniques in mitigating overvoltage issues due to high PV integration. The performance of four reactive power control techniques namely, fixed power factor control, scheduled power factor control, power factor control as a function of injected active power, and voltage-dependent reactive power control were analyzed and compared in terms of the number of customers with voltage violations, reactive power compensation, and network losses. Three-phase, time-series, high-resolution power-flow simulations were performed to investigate the potential overvoltage issues and to assess the performance of the adoption of reactive power controls in the network. The simulation results revealed that the incorporation of reactive power controls of solar PV inverters aids in successfully mitigating the overvoltage issues of typical Malaysian networks. In particular, the Volt-Var control outperformed the other control techniques by providing effective voltage regulation while requiring less reactive power compensation. Furthermore, the comparative analysis highlighted the significance of employing the most appropriate control technique for improved network performance.

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Voltage Regulation in Low-Voltage Distribution Grids with Reactive Power Control by Power Conditioning Subsystem Coordination

2019 International Conference on Smart Energy Systems and Technologies (SEST) ◽

10.1109/sest.2019.8849034 ◽

2019 ◽

Author(s):

Kentaro Fukushima ◽

Takuya Nayuki ◽

Hiroyuki Hatta ◽

Hiromu Kobayashi

Keyword(s):

Power Control ◽

Reactive Power ◽

Low Voltage ◽

Voltage Regulation ◽

Voltage Distribution ◽

Power Conditioning ◽

Reactive Power Control ◽

Distribution Grids

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A Hybrid Reactive Power Control Method of Distributed Generation to Mitigate Voltage Rise in Low-Voltage Grid

Energies ◽

10.3390/en13082078 ◽

2020 ◽

Vol 13 (8) ◽

pp. 2078 ◽

Cited By ~ 3

Author(s):

Soo-Bin Kim ◽

Seung-Ho Song

Keyword(s):

Power Control ◽

Reactive Power ◽

Control Method ◽

Low Voltage ◽

Voltage Regulation ◽

Active Power ◽

Reactive Power Control ◽

Voltage Rise ◽

Distributed Generator ◽

Network Losses

A high penetration of distributed generators, such as solar and wind power generators in low voltage network systems, impose voltage rise problems. Reactive power control of distributed generators can contribute to mitigating the voltage rise. In the existing reactive power control, reactive power was controlled using only one local variable, such as voltage at point of connection or the active power output of distributed generator. In case of PF(P) method, which provides certain power factors, depending on the active power of distributed generator, the voltage regulation ability is strong, but network losses are large. Q(V) method, which provides a certain amount of reactive power depending on the local voltage, has few network losses, but the voltage regulation ability is weak. In this paper, a reactive power control method that combines the PF(P) method and Q(V) method was proposed. The proposed method determines the reactive power output by using the active power of the distributed generator and local voltage variables together. The proposed method improves the voltage regulation ability of the reactive power control, while reducing the network losses, as compared to the existing method. The low voltage network system was modeled and simulated to evaluate the performance of the proposed method, in terms of voltage regulation ability and network losses, and the performance of the proposed method and the existing method were compared and analyzed.

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