Flux-weakening control for interior permanent magnet synchronous motor drive systems

To deal with the difficulty in the high frequency operation of interior permanent magnet synchronous motor (IPMSM) systems,a flux-weakening control method based on q-axis voltage is proposed.On the basis of the field-oriented control,the q-axis voltage is used to control the d-axis current,and the error signal of demagnetization current can be obtained by subtracting the feedback value from the reference value of the q-axis voltage.The demagnetization current can be obtained by using the PI operation of its error signal.To deal with the sharp drop in the DC bus voltage under heavy load,we introduce the effective work-time of the space voltage vector in the closed-loop for regulating the demagnetization current.The system model of IPMSM is built and the validity of the proposed flux-weakening method is verified by the simulation results.The proposed control method is applied in an inverter air-conditioner compressor control system.The experimental platform of flux-weakening control system is developed by STM32F103R8T6 ARM.It is shown that the speed range of IPMSM is extended by the proposed flux-weakening algorithm.