A V/Hz based Maximum Torque per Volt Control in Flux-Weakening Region for Interior Permanent Magnet Synchronous Motors

V/Hz control is suitable for cost effective, ease of use interior permanent magnet synchronous motor (IPMSM) applications such as fan and pump loads. However, the research findings with V/Hz control in flux-weakening region are rare, which limits the application of IPMSM at high speed. Although field oriented control (FOC) in flux-weakening region is realized, the output voltage of current controller is easily saturated due to the inverter voltage limitation, requiring a complicated desaturation strategy to deal with. In order to expand speed range of IPMSM, a simple and practical V/Hz control strategy in flux-weakening region with current amplitude and angle feedback is proposed. This method can achieve constant current control, maximum torque per volt (MTPV) control, as well as smooth transition between them. Theoretical analysis and simulation studies are carried out. Experimental results using a 1500W, 380Vrms, 1500rpm, IPMSM and adjustable speed drive (ASD) system are obtained for validating the effectiveness of the proposed V/Hz control solution.