Dead Zone Compensation Strategy for Inverter of PMSM Based on Direct Axis Voltage Analysis

The dead-zone effect will lead to the output voltage distortion of the inverter, so that the actual output voltage controlled by the PMSM SVPWM will not be equal to the reference voltage, which reduces the control performance. The inverter dead-zone effect of synchronous motor drive system is analyzed, the mathematical model of the output voltage including the dead-zone effect is established, and a dead-zone compensation strategy based on direct-axis voltage analysis is proposed. The size of dead zone can be identified online by analyzing voltage harmonics,then the feed forward voltage can be compensated according to the mathematical model. This method doesn’t need additional hardware, and is simple to implement. Simulation and experiment show that the method can effectively eliminate the voltage and current harmonics caused by the dead zone.