This device use active reactive power generator (SVG) to replace the minimum step capacity branch of common compensation device. Because SVG parts can output continuously, afterswitching capacitor TSC cooperated with SCR, the original output step error (intermittent compensation) can be eliminated, thus can achieve the purpose of whole machine capacity rapid and continuous output, so in the case that native machine has enough capacity, the effect that the whole course power factor is 1 can be realized.