无功功率测量分析

摘要

对对称分量法三序功率与三相功率间的关系进行了研究，当三相电路不对称时，采用单功率表跨相接线，两功率表跨相接线、三功率表跨相接线和用两功率表人工中性点接线测量无功功率，均存在原理性误差。用两元件移相90°能正确测量三相三线电路无功功率；用三元件移相90°能正确测量三相四线电路的功率功率。%This paper studies the relationship between 3 -sequence power and 3 -phase power in the symmetrical component method.In the case of asymmetrical 3-phase circuit,theoretic errors occur when reactive power is measured with cross-phase wiring of a single/double/triple power meter,or with an artificial neutral point wiring of a double power meter.The reactive power of a 3 -phase 3 -wiere circuit can be measured correctly by means of 90°phase shift of 2 elements,and the reactive power of a 3 -phase 4 -wire circuit can be measured correctly by means of 90°phase shift of 3 elements.