Evaluation of the Influence of AC Voltage Regulators, SVC and Unified Power Controllers on Power Losses and Quality in Unsymmetrical Distribution Systems

Paper Info

This paper investigates the impact of AC Voltage Regulators, Static VAR Compensators (SVC), and Unified Power Controllers (UPC) on power losses and quality in unsymmetrical distribution systems. It delves into the principles of operation of these devices and their implementation in power flow studies. The study employs the Newton-Raphson method and Carson equation to analyze the performance of the IEEE-13 bus unbalanced distribution model. An optimization study is conducted to determine the optimal mode of operation for each device to minimize power losses and unbalanced coefficients. The genetic algorithm (GA) is utilized to find the best operating conditions for these devices in an unbalanced distribution system.

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Recommended citation: D. I. Panfilov, A. M. Elkholy and A. E. ELGebaly, “Evaluation of the Influence of AC Voltage Regulators, SVC and Unified Power Controllers on Power Losses and Quality in Unsymmetrical Distribution Systems,” 2023 IEEE 24th International Conference of Young Professionals in Electron Devices and Materials (EDM), Novosibirsk, Russian Federation, 2023, pp. 950-956, doi: 10.1109/EDM58354.2023.10225221.

Key points covered in the article:

Background and Motivation:

The paper addresses the critical issue of managing unbalance in power systems, particularly due to the increasing use of sensitive loads and distributed generation (DG) units. Unbalanced operation can lead to voltage drops, power losses, harmonic distortion, and equipment damage. The study aims to evaluate the compensation of zero or negative sequence components in the distribution system, which are caused by unbalanced loads or faults.

Challenges and Solutions:

The paper highlights the need for devices capable of compensating for the negative and zero sequence components of currents in distribution systems. The compensation of zero sequence component is more significant than traditional reactive power compensation. The UPC device is proposed as an optimal solution to reduce system losses to a minimum and adjust the voltage unbalancing coefficient, whether from the negative or zero current component.

Methodology:

The research employs the IEEE 13 bus system as a standard test case for studying the effects of unbalance on power distribution systems. It consists of a single 4.16 kV feeder with one voltage regulator at the substation and several branches with different types of loads and components. The paper evaluates the benefits of compensating zero and negative sequence components in addition to reactive power compensation, aiming to improve power quality, stability, and efficiency.

Case Study:

The IEEE 13 bus system is used as a case study to analyze various scenarios such as load flow, voltage regulation, harmonic distortion, solar PV integration, using different software tools such as MATLAB/Simulink. The data and models of the IEEE 13 bus system are available here.

Research Results:

The paper presents results of the analysis, including dependencies between negative-sequence voltage-unbalance coefficients, energy losses, and energy transfer efficiency on factors like load asymmetry, transmission line parameters, and load factors. The results show that UPC can achieve significant reduction in UDSL and UVC compared to ZZT and no compensation cases.

Universal Power Controller:

The paper proposes a universal power controller (UPC) that uses measured currents and voltages to determine control actions for mitigating load asymmetry effects. The UPC device can simultaneously compensate for both reactive power and zero sequence current components. The paper demonstrates that the UPC device can achieve optimal performance by minimizing the power losses and adjusting the UVC to acceptable levels under various loading conditions.

Citation for the Paper

D. I. Panfilov, A. M. Elkholy and A. E. ELGebaly, “Evaluation of the Influence of AC Voltage Regulators, SVC and Unified Power Controllers on Power Losses and Quality in Unsymmetrical Distribution Systems,” 2023 IEEE 24th International Conference of Young Professionals in Electron Devices and Materials (EDM), Novosibirsk, Russian Federation, 2023, pp. 950-956, doi: 10.1109/EDM58354.2023.10225221.

Abstract: This paper studies the performance of unbalanced three-phase distribution systems under the correction effect of Unified Power Controller (UPC), static VAR compensators (SVC) and AC voltage regulators (booster). In this paper, the principle of operation of each of suggested devices is developed to obtain the proper model to be implemented in power flow study. The Newton-Raphson method and Carson equation are integrated to analyse the performance of the IEEE-13 bus unbalanced distribution model. Optimization study is conducted to decide the mode of operation of each proposed device to improve the system asymmetry. The objective function is formulated to have both power losses and unbalanced coefficients that should be minimized. The genetic algorithm (GA) is used to determine the mode of operation of each device when it is applied in an unbalanced distribution system. This study is an essential step to analyse the unbalanced distribution system enhanced by power electronics-based devices to reduce the asymmetry of the system in an optimized manner.

keywords: {Performance evaluation;Analytical models;Regulators;Static VAr compensators;Mathematical models;Power electronics;Voltage control;unbalanced distribution system;unbalanced power flow;Unified Power Controller;SVC;AC voltage regulator;Voltage Booster}, URL: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10225221&isnumber=10225012