High frequency voltage injection for IPMSM rotor position detection with GaN inverter and FPGA control

Due to GaN semiconductors, the switching frequency of the inverter can be significantly increased compared to an IGBT inverter. With the increased switching frequency, the frequency of the injected voltage signal can be also increased for the sensorless control of PMSM based on high-frequency (HF) carrier-signal injection. More over, to control the GaN inverter, the well known algorithms for PWM generation, algorithms for HF signal injection, and the current sensing must be implemented in an FPGA, which offers the posiblity of improving the rotor position estimation. In this paper, a novel sensorless rotor position estimation algorithm using a HF square wave voltage is designed and ultilized in an FPGA. Using the HDL Coder (Hardware description language), the validated algorithm is successfully tested in a test bench consisting of a interior permanent magnet synchronous motor (IPMSM), 3-phase-GaN-inverter and a real time computer. With the result of the proposed method, a comparison with the well known PI position estimator is performed.