Extension of Space Vector Signal Injection MTPA Control for IPMSM Into Deep Flux-Weakening Region

To guarantee the minimum copper loss of interior permanent magnet synchronous motors in a wide operating range, space vector signal injection (SVSI) control combining with flux-weakening control scheme is presented in this paper. The SVSI control can track the maximum torque per ampere points, but due to voltage saturation, it is invalid in the deep flux-weakening region. A new strategy is proposed to select the optimal current commend to minimize copper loss in wide speed range. The presented strategy is based on the difference between a proper limit value and the amplitude of voltage vector. The difference is utilized to adjust the angle of current vector when voltage saturation by SVSI control is detected. The proposed strategy is parameter independent. The simulation results demonstrate the feasibility of the presented method.