Maximum Torque per Ampere Control Using Hill-Climbing Method Based on V/f Control for Interior Permanent Magnet Synchronous Motor

Abstract

This paper proposes a novel V/f control method for interior permanent magnet synchronous motors (IPMSMs) in order to achieve maximum torque per ampere (MTPA) control without motor parameters such as d-q axis inductance and flux linkage of a permanent magnet. V/f control does not require either information of rotor position or the motor parameters in order to construct the control system. However, the conventional MTPA control method requires the motor parameters because the control determines the compensation voltage depending on reactive power. On the other hand, in the proposed MTPA control method, a hill-climbing method is utilized. The proposed MTPA control method calculates the compensation voltage depending on the output current in order to track the MTPA operation point without the motor parameters. The validity of the proposed method is confirmed by the experimental results using a 3.7-kW IPMSM. The experimental results indicate that the magnitude of the phase current decreased by 61% at the rated speed. Furthermore, the proposed MTPA control method is effective regardless of the magnitude of the load torque.