Investigation of Pulsating Vector Excitation Saliency-based Rotor Position Estimation Method in Current-Source Inverters

While many self-sensing (sensorless) control methods have been developed for voltage source inverters (VSIs), there has been limited investigation into how these methods perform with current-source inverter (CSI) drives, which are becoming more attractive with recent advances in monolithic four-quadrant switches. This paper presents a pulsating vector excitation saliency-based rotor position estimation method that can be adapted for CSI-based motor drives. The benefits of using CSIs are discussed, including improved voltage measurement accuracy and compatibility with low-inductance machines. This paper explains how to tailor the pulsating vector excitation saliency-based method for CSI-based motor drives, with a focus on the important issues of capacitor unbalance effects and CSI-load resonances. A detailed mathematical model for the rotor position estimation method is provided, together with experimental verification results.