Improved CPC-based parameter calculation of passive balancing compensation in three-phase four-wire systems with unbalanced loads

• Published in: International journal of electrical power & energy systems Vol. 150; p. 109076
• Main Authors: Tao, Shun, Shen, Junyan, Song, Yidan, Guan, Shangshu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2023
• Subjects: CPC Theory; Load imbalance; Passive compensation; Three-phase four-wire system; Voltage asymmetry; Three-phase four-wire system; Passive compensation; Load imbalance; Voltage asymmetry; CPC Theory
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2023.109076

•The subject of this paper is the parameter calculation method of passive balancing compensation in 3P-4 W low voltage systems with unbalanced loads to overcome limitations of compensator parameter algorithm based on CPC. The main contributions of this paper are as follows:•The fundamental frequency current is decomposed from the point of view of parallel compensation, including fundamental optimal working current iw1, active current ia1, reactive current ir1, voltage asymmetry dependent current id1, positive-sequence, negative-sequence and zero-sequence unbalanced currents (iu1+,iu1-,iu10).•The parameter calculation method of passive balancing compensator oriented the fundamental current components is developed in 3P-4 W systems supplying unbalanced and linear load. Four compensation levels are presented when one or some components of the detrimental current are selected as compensation objects in the parameter calculation process. The fully compensation is achieved in Level 4 where the system works most effectively with the fundamental optimal working current iw1.•The method takes into account the influence of line impedances and nonsinusoidal voltages on the compensator parameter calculation, so it is suitable for four-wire system with symmetrical or asymmetrical, sinusoidal or nonsinusoidal supply voltages. The unbalanced loads in low voltage three-phase four-wire(3P-4W) systems increase the energy and the voltage losses of the power supply system, and even cause serious voltage deviations. The passive compensation method using the Currents’ Physical Components (CPC) – based power theory does not consider the voltage losses of phase and neutral line impedances, and it is only suitable for the situations of symmetrical voltage. Under the conditions of supply voltage distortion, load unbalance and the consideration of line impedances, this paper improves the calculation method of passive compensation parameters oriented the current components in four-wire systems, which can make the system work efficiently with the fundamental optimal working current balanced without harmonic amplification. The effectiveness and adaptability of the proposed method to the background conditions are verified, based on the comparison of MATLAB / Simulink simulation results.