A Virtual HF Signal Injection Based Maximum Efficiency per Ampere Tracking Control for IPMSM Drive

In this article, a virtual high-frequency signal injection based searching method is proposed to derive the optimal current angle for the maximum efficiency per ampere control of interior permanent magnet synchronous machine (IPMSM) drive system. It injects a small virtual square wave HF signal into the mathematical model of IPMSM drive system including both the electrical machine and inverter, by which the optimal current angle could be accurately derived afterward. It is finally tested on a 1-kW prototype IPMSM and shows a good searching accuracy and dynamic performance while the system loss and torque ripple will not increase thanks to the virtualized signal injection.