Abstract: Using the capacitors connected parallel with threephase asynchronous motor to realize reactive power compensation for raising the total power factor is the widelyused method for increasing the motor operation power factor. Based on the analysis of operation characteristics of highvoltage asynchronous motor in pump station of water conservation project with different load factor, a new method to select the capacity of the capacitor parallel connected with three phase highvoltage asynchronous motor was put forward. Favorable compensation effect of the motor reactive compensation capacity configured by this method was obtained in practical operation.

Key words: asynchronous motor, reactive power, natural power factor, total power factor, reactive power compensation, parallel connected capacitor, capacity selection