二表法测量三相电路有功功率

Three-phase Circuit Power Measuring with Two-wattmeter

依据二表法测量三相电路有功功率的原理,分析和讨论了在采用二表法测量三相三线制有功功率时,电路中各线电压和线电流之间的关系。围绕有功功率表的读数等于该功率表电压线圈所接电压的有效值、电流线圈所通过的电流的有效值以及电压与电流相位差余弦的乘积这一重要的概念,用实例说明在不同的接线情况下如何利用各电量的相量关系来确定所测的线电压、线电流之间的相位差角。方法简单、实用。

According to the principle of three-phase circuit power measuring with two-wattmeter,the relation between line voltage and line current was analysed in this paper in adopt two-wattmeter methods to measure the power of Three-phase Three-wire circuit.With this important concept which the reads of wattmeter was equal to the product of the effective value of the voltage across the potential coil,the effective value of the current flowing in the current coil,and the cosine of the phase-angle between the current and the voltage.It was speciled with some examples to determine the phase-angle measured between line voltage,line current in different connection.The method was simple and practical.