Current regulation for surface permanent-magnet synchronous motor drives using integrated current sensors in low-side switches

A new synchronous-frame current-regulator configuration for a surface permanent-magnet machine is presented, which utilizes incomplete phase-current measurements from the integrated pilot current sensors to deliver an attractive regulator performance. Since the pilot current sensors are directly integrated into the power switching devices, they provide opportunities to reduce the cost, size, and weight of the three-phase inverters by eliminating the dedicated current sensors in the motor-drive applications. However, a three-phase inverter equipped with these sensors in the three low-side switches cannot measure the complete load-current waveforms, requiring the development of this new current-regulator algorithm. An autotuning method is described that significantly reduces the sensitivity of the regulator to errors in the estimated machine parameters. Experimental results are provided to verify the appealing performance characteristics of the proposed regulator.