Power Perturbation based Virtual Signal Injection Control of MTPA for IPMSM Drive System

A novel online maximum torque per ampere (MTPA) control method based on power perturbation derived from virtual signal injection (VSI) for an interior permanent magnet synchronous motor (IPMSM) is proposed in this paper. The key of the proposed method is that the high-frequency signal is mathematically injected into the current angle and the corresponding power perturbation is utilized to generate the current angle reference. An accurate equation is proposed to calculate electromagnetic power after signal injection, which guarantees the accuracy of MTPA tracking. This control method is parameter independent and no real signal is injected into the current or voltage command, which avoids additional copper loss. The performances at start-up and low speed region are improved. Simulations under different operation situations are carried out to verify the effectiveness of the proposed control strategy.