A multiple vectors voltage waveform modulation method for microgrid inverter

Voltage waveform distortion scenario exists and this phenomenon greatly diminishes the efficiency of electric power conversion when the conventional SVPWM method is applied in microgrid inverter. In order to solve the problems, a Multiple Vectors Pulse Width Modulation (MVPWM) method based on 12 voltage vectors is proposed. The modulation method we proposed defines 12 voltage vectors in the space vector plane and the reference voltage vector is created by synthesizing two adjacent voltage vectors and the zero voltage vectors. The proposed method does not lose some advantages which belong to conventional SVPWM method such as simplified calculation character and easy implementation feature. Furthermore, MVPWM can effectively avoid the upper and lower switch states of a leg short-circuiting the voltage source so that there is no additional requirement to set the dead-time. Therefore, the effect of dead-time to the inverter and the distortion of voltage waveform can be decreased. From another perspective, the efficiency of electric power conversion can be increased. The validity of the proposed MVPWM method has been verified by both theoretical analysis and simulation results.