他励直流电动机可变电阻型等效电路图及其应用

Variable Resistance Equivalent Circuit of the Separately Excited DC Motor and its Application

若将他励直流电动机输出功率的机理等效为一个与电动机电枢绕组并联的可变电阻，可以得到他励直流电动机可变电阻型等效电路图。此等效电路图适用于电动机转速的任意变化范围，特别是起动与制动过程中各种特性参数的分析与计算。本文利用此等效电路图计算出起动过程中电枢电流、转速、电枢绕组中的功率损耗、效率等参数。并证明了常见的油阻尼器型等效电路图是可变电阻型等效电路图的一个特例，它仅适用于电动机的转速在稳定运行点附近小范围波动的情况。

The output power mechanism of a separately excited DC motor can be equivalent to a variable resistance,which is parallel with the armature winding of the motor. Therefore,the variable resistance equivalent circuit of the separately excited DC motor can be obtained. It is suitable to any range of the motor speed. It is useful to analyze and calculate all kinds of characteristics,such as the armature winding efficiency etc. during starting and breaking. It is proved that the oil damper equivalent circuit of the separately excited DC motor is a special case of the variable resistance equivalent circuit. The oil damper equivalent circuit is only suitable to a limited speed range around the stable operating point.