Voltage Regulation through Wide Area Voltage Control of HV/MV Transformers and Inverters’ Reactive Power Support

Inertia reduction due to inverter-based resource (IBR) penetration deteriorates power system stability, which can be addressed using virtual inertia (VI) control. There are two types of implementation methods for VI control: grid-following (GFL) and grid-forming (GFM). There is an apparent difference among them for the voltage regulation capability, because the GFM controls IBR to act as a voltage source and GFL controls it to act as a current source. The difference affects the performance of the VI control function, because stable voltage conditions help the inertial response to contribute to system stability. However, GFL can provide the voltage control function with reactive power controllability, and it can be activated simultaneously with the VI control function. This study analyzes the performance of GFL-type VI control with a voltage control function for frequency stability improvement. The results show that the voltage control function decreases the voltage variation caused by the fault, improving the responsivity of the VI function. In addition, it is found that the voltage control is effective in suppressing the power swing among synchronous generators. The clarification of the contribution of the voltage control function to the performance of the VI control is novelty of this paper.

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A consensus-based voltage control for reactive power sharing and PCC voltage regulation in microgrids with parallel-connected inverters

2019 18th European Control Conference (ECC) ◽

10.23919/ecc.2019.8795924 ◽

2019 ◽

Author(s):

Ajay Krishna ◽

Johannes Schiffer ◽

Nima Monshizadeh ◽

Jorg Raisch

Keyword(s):

Reactive Power ◽

Voltage Control ◽

Voltage Regulation ◽

Power Sharing

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Power factor control of PV generators in local distribution networks using fuzzy logic concept

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.28.13211 ◽

2018 ◽

Vol 7 (2.28) ◽

pp. 362

Author(s):

Raed A. Shalwala

Keyword(s):

Fuzzy Logic ◽

Control System ◽

Power Factor ◽

Fuzzy Logic Control ◽

Reactive Power ◽

Distribution Network ◽

Voltage Control ◽

Distribution Networks ◽

Voltage Regulation ◽

Logic Control

One of the most important operational requirements for any electrical power network for both distribution and transmission level is voltage control. Many studies have been carried out to improve or develop new voltage control techniques to facilitate safe connection of distributed generation. In Saudi Arabia, due to environmental, economic and development perspectives, a wide integration of photovoltaic (PV) genera-tion in distribution network is expected in the near future. This development in the network may cause voltage regulation problems due to the interaction with the existing conventional control system. In a previous paper, a control system has been described using a fuzzy logic control to set the on-line tap changer for the primary substation. In this paper a new control system is proposed for controlling the power factor of individual PV invertors based on observed correlation between net active and reactive power at each connection. A fuzzy logic control has been designed to alter the power factor for the remote invertors from the secondary substation to keep the feeder voltage within the permissible limits. In order to confirm the validity of the proposed method, simulations are carried out for a realistic distribution network with real data for load and solar radiation. Results showing the performance of the new control method are presented and discussed.

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Secondary voltage regulation based on average voltage control

TecnoLógicas ◽

10.22430/22565337.779 ◽

2018 ◽

Vol 21 (42) ◽

pp. 63-78

Author(s):

Edwin H. Lopera-Mazo ◽

Jairo Espinosa

Keyword(s):

Control System ◽

Power Systems ◽

Reactive Power ◽

Voltage Control ◽

Voltage Regulation ◽

Voltage Profile ◽

Real Power ◽

Power Resources ◽

Control Actions ◽

Secondary Voltage

This paper compares a conventional Secondary Voltage Regulation (SVR) scheme based on pilot nodes with a proposed SVR that takes into account average voltages of control zones. Voltage control significance for the operation of power systems has promoted several strategies in order to deal with this problem. However, the Hierarchical Voltage Control System (HVCS) is the only scheme effectively implemented with some relevant applications into real power systems.The HVCS divides the voltage control problem into three recognized stages. Among them, the SVR is responsible for managing reactive power resources to improve network voltage profile. Conventional SVR is based on dividing the system into some electrically distant zones and controlling the voltage levels of some specific nodes in the system named pilot nodes, whose voltage levels are accepted as appropriate indicators of network voltage profile.The SVR approach proposed in this work does not only consider the voltage on pilot nodes, but it also takes the average voltages of the defined zones to carry out their respective control actions. Additionally, this innovative approach allows to integrate more reactive power resources into each zone according to some previously defined participation factors.The comparison between these strategies shows that the proposed SVR achieves a better allocation of reactive power in the system than conventional SVR, and it is able to keep the desired voltage profile, which has been expressed in terms of network average voltage.

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Adaptive Voltage Control of Distribution Network with High Proportion PV

E3S Web of Conferences ◽

10.1051/e3sconf/202125201033 ◽

2021 ◽

Vol 252 ◽

pp. 01033

Author(s):

Junchao Ma ◽

Xiaoming Huang ◽

Boliang Lou ◽

Xiulin Xiao ◽

Yinlong Fan ◽

...

Keyword(s):

Control Strategy ◽

Reactive Power ◽

Distribution Network ◽

Voltage Control ◽

Voltage Regulation ◽

Extremum Seeking ◽

Pv System ◽

Voltage Control Strategy ◽

Voltage Controller ◽

Point Of Common Coupling

With the increase of grid-connected PV capacity, voltage regulation at point of common coupling by controlling the reactive power injected into the grid is available. This paper presents an adaptive voltage control strategy for distribution network with high proportion PV system. The PI gain of the voltage controller is automatically adjusted by the extremum seeking algorithm to dynamically respond to the changes of the network. The PI gains are updated online through the minimization of a cost function, which represents the voltage controller performance. Finally, a distribution network model of 5 MW photovoltaic power generation system is built in MATLAB / Simulink to verify the effectiveness of the proposed control strategy.

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Stochastic Analysis-Based Volt–Var Curve of Smart Inverters for Combined Voltage Regulation in Distribution Networks

Energies ◽

10.3390/en14102785 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2785

Author(s):

Dongwon Lee ◽

Changhee Han ◽

Gilsoo Jang

Keyword(s):

Reactive Power ◽

Control Method ◽

Flow Analysis ◽

Voltage Control ◽

Distribution Networks ◽

Voltage Regulation ◽

Load Flow ◽

Renewable Energy Resources ◽

Voltage Profile ◽

Smart Inverters

The proliferation of renewable energy resources (RES), especially solar photovoltaic (PV) generation resources, causes overvoltage and line overloading in distribution networks. This study proposes a two-level volt–var control method based on multiple timescales. The on-load tap changer (OLTC) operates on an hourly timescale, to regulate the voltage on the secondary winding. In the 15-minutes timescale, PV-connected smart inverters and static var compensators (SVCs) are obliged to compensate the reactive power for the voltage control at the point of common coupling. In the multi-timescale voltage control framework, this study proposes a new multi-sectional volt–var curve (MSVVC) of a PV inverter. The objective of the MSVVC is to minimize the energy loss in the network, improve the voltage profile, and obtain the operational margin of other reactive power compensation devices. In the process of determining the optimal parameters of the MSVVC, stochastic modeling-based load flow analysis is utilized to consider the intermittency and uncertainty of RES generation. The effectiveness of the proposed method is verified on the IEEE 33-bus system in comparison with the conventional volt–var curve cases.

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