Nonlinear controller design for a sensorless matrix-converter IPMSM drive system

This paper proposes a sensorless matrix-converter IPMSM drive system based on detecting the PWM switching-state current-ripples. By detecting the current-ripple of each PWM switching-state, the rotor position of the IPMSM can be estimated. As a result, the circuit of high-frequency sinusoidal voltage or current source is not required. A nonlinear controller is proposed here. The proposed nonlinear controller can provide fast transient responses, good load disturbance responses, and satisfactory tracking responses. Moreover, the nonlinear controller is very simple and easy to be implemented. Experimental results show that the proposed nonlinear controller has better performance than the PI controller does. A 32-bit digital signal processor, TMS-320LF-2407A, is used to execute the rotor position estimation algorithm and the whole control algorithm. Experimental results can validate the theoretical analysis. The proposed sensorless IPMSM drive can be operated from 10 r/min to 2000 r/min. This paper proposed a new direction to implement a matrix-converter IPMSM drive system without injecting a high-frequency voltage or current.