A generalised instantaneous non-active power theory for STATCOM

• Published in: IET electric power applications Vol. 1; no. 6; pp. 853 - 861
• Main Authors: XU, Y, TOLBERT, L. M, CHIASSON, J. N, CAMPBELL, J. B, PENG, F. Z
• Format: Journal Article
• Language: English
• Published: London Institution of engineering and technology 01.11.2007; The Institution of Engineering & Technology
• Subjects: Applied sciences; Balancing; Convertors; Disturbances. Regulation. Protection; Dynamic response; Electric potential; Electric power generation; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Exact sciences and technology; Mathematical analysis; Miscellaneous; Power networks and lines; Unity; Utilities; Voltage; Dynamic response; Averaging method; Rectifier; Flexible AC transmission systems; Unbalanced conditions; Experimental study; Algorithm; Implementation; Charge compensation; Static reactive compensator; Electrical network; Active system; Three phase circuit; Active component; Reference voltage; Power factor; Apparent power
• ISSN: 1751-8660; 1751-8679
• DOI: 10.1049/iet-epa:20060290

A generalised instantaneous non-active power theory is presented. Comprehensive definitions of instantaneous active and non-active currents, as well as instantaneous, average and apparent powers, are proposed. These definitions have flexible forms that are applicable to different power systems, such as single-phase or multi-phase, periodic or non-periodic and balanced or unbalanced systems. By changing the averaging interval and the reference voltage, various non-active power theories can be derived from this theory. The definitions of instantaneous active and non-active currents provide an algorithm for a STATCOM to calculate the non-active current in the load current. The theory is implemented by the STATCOM, and four cases (three-phase balanced RL load, three-phase unbalanced RL load, diode rectifier load and single-phase load) are tested. The experimental results show that the STATCOM can perform instantaneous non-active power compensation, and both the fundamental non-active component and the harmonics are eliminated from the utility, so that nearly unity power factor can be achieved. The STATCOM also has a fast dynamic response for transients.