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

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2078 ◽  
Author(s):  
Soo-Bin Kim ◽  
Seung-Ho Song

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.

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4364 ◽  
Author(s):  
Ou-Yang ◽  
Long ◽  
Du ◽  
Diao ◽  
Li

As loads connected to active distribution network (ADN) grow, ADN’s voltage safety issues are becoming more serious. At present, the solution is mainly to build more distributed generation (DG) or to adjust the reactive power in the whole network, but the former needs a lot of investment while the latter requires a large amount of communication equipment and it takes a long time to calculate the adjustment amount of reactive power and to coordinate reactive power compensation equipment. When the loads are heavy, there will still be drawbacks of insufficient reactive power. Therefore, this paper analyzes the relationship between the active power, reactive power, and the voltage in the ADN. Through the autonomous region (AR) division, a voltage control method based on the active power variation and adjustable power in the AR is proposed. According to the relationship between the amount of active power and the adjustable amount active power, the active power control, the reactive power control, and the coordinated control of active power reactive power control are adopted to adjust the DGs’ output to stabilize the bus voltage. The simulation results show that the proposed method can effectively improve the voltage control capability of ADN and can enable it to operate normally under greater power changes. Through the control method in this paper, the communication requirements are greatly reduced and the calculation time is effectively shortened and is more adaptable.


2018 ◽  
Vol 119 ◽  
pp. 504-512 ◽  
Author(s):  
Maryam Hasheminamin ◽  
Vassilios Georgios Agelidis ◽  
Abdollah Ahmadi ◽  
Pierluigi Siano ◽  
Remus Teodorescu

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1569
Author(s):  
Dilini Almeida ◽  
Jagadeesh Pasupuleti ◽  
Janaka Ekanayake

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.


2015 ◽  
Vol 781 ◽  
pp. 388-392
Author(s):  
Piyadanai Pachanapan ◽  
Suttichai Premrudeepreechacharn

The coordinated reactive power control among photovoltaic (PV) systems, without communication requirement, is introduced to prevent the over-voltage problems in radial distribution networks. The voltage source inverter in PV system can provide the reactive power control to deal with the dynamic voltage variations. Two reactive power control methods, Q(P) and Q(V), can be employed into each PV system depending on its location. The dynamic voltage control performances are examined on simulation in DIgSILENT PowerFactory software. The results showed that the proposed control method can mitigate the rise of voltage level sufficiently.


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3437 ◽  
Author(s):  
Dario Garozzo ◽  
Giuseppe Marco Tina

The increasing presence of distributed generation (DG) in the electrical grid determines new challenges in grid operations, especially in terms of voltage and frequency regulation. Recently, several grid codes have required photovoltaic (PV) inverters to control their reactive power output in order to provide voltage regulation services, and the allocation of a certain amount of active power reserve for fast frequency response (FFR) service during under-frequency contingencies is needed. This requirement involves a significant waste of energy for PV systems, due to the necessity to constantly operate in de-loaded mode, under normal operating conditions. In addition, the variability of the irradiance can affect the correct amount of active power reserve that the system can provide in the moments after an under-frequency occurrence. The increasing number of battery energy storage systems (BESSs), coupled to PV systems, can be used to provide a worthy contribution to this frequency regulation service. The aim of this paper is to analyze the efficiency of active power reserve provided by a BESS connected to the DC bus of a non-ideal grid-connected PV inverter, taking into account the impact of reactive power control. For this purpose, the contribution of BESSs to frequency regulation is discussed and, starting from an existing model of real inverter, an analytical formulation for active power reserve evaluation is presented. Results concerning the impact of reactive power control are also given. Finally, the possibility for a low voltage (LV) grid with aggregated PV systems and BESSs to contribute to grid active power reserve is considered. Different voltage control strategies are compared, defining a helpful new parameter.


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