DIRECT-AXIS CURRENT PROTECTION METHOD AND DEVICE FOR PERMANENT MAGNET SYNCHRONOUS MOTOR DRIVE SYSTEM

摘要

A direct-axis current protection method and device for a permanent magnet synchronous motor drive system. The method includes: pre-calculating the direct-axis current of the next moment according to the current voltage transmitted from an inverter to a permanent magnet synchronous motor (PMSM) (S301); comparing the direct-axis current of the next moment with a maximum protection current (S302); if the direct-axis current of the next moment is less than the maximum protection current, continuing transmitting the current voltage to the PMSM (S303); if the direct axis current of the next moment is greater than or equal to the maximum protection current, redistributing the voltage according to a protection direct-axis current and a protection quadrature-axis current, and transmitting the redistributed voltage to the PMSM (S304). The direct-axis current of the next moment is tended to be normal by adjusting the voltage. In the case that the PMSM working load is constant, the redistributed voltage is transmitted to the PMSM. By pre-calculating the direct-axis current of the next moment, the actual operating condition of the PMSM is simulated, and protection is performed when the direct-axis current of the next moment exceeds the limitation.