Evaluation of Zero and Negative Sequence Currents Influence of Asymmetric Load on the Power Losses and Quality in Distribution Networks
Published:
Recommended citation: A. M. Elkholy, D. I. Panfilov and A. E. El Gebaly, "Evaluation of Zero and Negative Sequence Currents Influence of Asymmetric Load on the Power Losses and Quality in Distribution Networks," 2023 IEEE 24th International Conference of Young Professionals in Electron Devices and Materials (EDM), Novosibirsk, Russian Federation, 2023, pp. 1110-1115, doi: 10.1109/EDM58354.2023.10225208. https://doi.org/10.1109/EDM58354.2023.10225208
Paper Info
Researchers and system engineers have given distribution system power quality issues a lot of attention recently. Due to the rising use of sensitive loads in the distribution system, difficulties with unbalanced voltage coefficient and losses are given the utmost attention among the many power quality challenges. This paper studies the effect of the various compensation devices of zero, negative and reactive current components on both the unbalanced distribution system losses and the unbalanced voltage coefficient. The effect of the conventional zero current compensators such as zigzag transformer is compared with modern unified power control (UPC) which can compensate not only zero current component but also the negative and reactive current components. This paper develops a method to evaluate the performance of various compensators on the losses and unbalanced voltage coefficient if these devices are applied in IEEE 13 bus unbalanced system loaded by standard daily loading. This paper provides a general platform to evaluate the unbalanced distribution system’s performance under various proposed compensators’ effect.
Recommended citation: A. M. Elkholy, D. I. Panfilov and A. E. El Gebaly, “Evaluation of Zero and Negative Sequence Currents Influence of Asymmetric Load on the Power Losses and Quality in Distribution Networks,” 2023 IEEE 24th International Conference of Young Professionals in Electron Devices and Materials (EDM), Novosibirsk, Russian Federation, 2023, pp. 1110-1115, doi: 10.1109/EDM58354.2023.10225208.
Key points covered in the article:
Background and Motivation:
The paper discusses the growing importance of managing unbalance in power systems due to the increasing use of sensitive loads and distributed generation (DG) units. Unbalanced operation of the distribution system can cause voltage drops, power losses, harmonic distortion, and equipment damage. The paper 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 that can compensate for the negative and zero sequence components of currents in distribution systems. The compensation of zero sequence component is more significant than the traditional reactive power compensation. In general, the UPC device can play the optimal role to reduce the system losses to minimum in addition to the adjustment of the voltage unbalancing coefficient whether from the negative or zero current component.
Methodology:
The research uses 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 also evaluates the benefits of compensating zero and negative sequence components in addition to reactive power compensation, which can 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.