Fig. 12 and Fig. 13 represent the phase voltage, line current and DC bus waveforms at speed motor 700 rpm and 1400 rpm. It can be seen that the signals of the current are distortion from sine wave. This is because of the way of adjusting duty cycle. The DC voltage, ripple signal is used to drive line current and DC bus will flow into noncontinuous pulses. It can be solved by adding more DC inductor into the circuit, so that the current flows smoothly, which also reduces ripple torque.