Predictive Controllers for Dual-Voltage Vector Current-Slope Sensorless IPMSM Drives

A rotor position estimation method based on a dual-voltage vector modulation technique for an IPMSM drive system is proposed in this paper. This method effectively increases the differences of the current slope in each switching state when compared to a single-voltage vector modulation technique, and it improves the current tracking capability of the current control as well as the accuracy of the rotor position estimation. The duty cycles of the dual-voltage vectors are systematically derived to generate the PWM switching states of the inverter. By measuring the current slope in each PWM switching state, the rotor position is easily estimated. In addition, the pulse width of the voltage vectors is not too narrow and does not require any extension or compensation. A predictive speed controller and a predictive current controller are designed and implemented to improve the dynamic responses of the drive system. All of the control algorithms, including dual-voltage vector modulation, rotor position estimation, and predictive control are realized through a DSP TMS-320F-2808. Experimental results show the proposed method provides an adjustable speed from 1 r/min to 2000 r/min with good performance, including transient responses, external load disturbance rejection, reversing speed, and tracking capability.