Performance Comparison of ZDAC vs MTPA for Permanent Magnet Synchronous Motor (PMSM) Control

The permanent magnet synchronous motor (PMSM) consists of two types, namely surface mounted PMSM (SPMSM) and interior PMSM (IPMSM). IPMSM has the potential to generate a greater torque than SPMSM due to its torque reluctance. To exploit this potential, a comparison of two control methods is conducted, namely ZDAC (zero d-axis current control) vs MTPA (maximum torque per ampere) control. Testing between these two control methods was carried out with variations in speed and load, and it was found that ZDAC could not maximize reluctance torque, because of that limiting the torque capability. MTPA control is applied to optimize efficiency. Compared to ZDAC or Id=0 A, MTPA control can produce maximum electromagnetic torque with smaller stator current values. Therefore, in the constant torque region or below the base speed, the IPMSM is controlled with MTPA to obtain better efficiency in motor operation.