三相交流电的教学,是一个比较复杂的问题,因为平常在讲述三相交流电的电流、电动势时,总是用一正弦或余弦函数亲表示。因而使人感到抽象,特别是对三角知识和矢量知识不够时,就更感困难。为了教学的直观,为了不应用三角知识也明确其电流的变化(只限于 The teaching of three-phase alternating current is a more complicated issue, because usually the three-phase AC current, the electromotive force, is always represented by a sine or cosine function. This makes people feel abstract, especially when knowledge of triangles and vectors is not enough. For instructional purposes, it is also clear that changes in current are not applied to the application of triangular knowledge (only