三相电路功率的测量方法

三相电路功率的测量是三相电路分析的重要内容，也是学生学习“电路原理”课程中三相电路部分的难点之一。本文按三相三线制和三相四线制分类，较详细地讨论了三相电路功率测量的接线问题。首先介绍了现有教材中已给出的三相电路功率的测量方法，进而提出了三相四线制三相电路功率测量的另三种接线方法。总结了两表法和三表法各自的适用范围及功率表读数在不同接线方式下的物理意义，指出了它们的联系与区别。最后，讨论了三相电路功率与三端和四端网络功率的联系以便更好地理解三相功率的测量方法。’

The Methods of Three-Phase Circuit Power Measurement

The power measurement is an important part of three phase circuit analysis. At the same time, it is also a difficult point for student to learn the principle of circuit. In this paper, according to three phase three wire systems and three phase four wire systems, the connection methods of three phase power measurement are discussed in detail. Firstly,the existing methods of the three phase power measurement in the teaching materials are introduced. And then another three connection methods are suggested for three phase four wire circuits. The applicability of different measurement methods and the meaning of wattmeter readings are summarized. The relationship and the difference of the different power measurement techniques are summarized. Lastly, the relation between the three phase power and the power of the three terminal networks and the four terminal networks are discussed in order to understand the three phase power measurement techniques more clearly.