Lower-Cost Sensorless Vector Control Method for Three-Phase PMSMs That Uses One-Shunt Current Detection

Sensorless vector control (SVC) of three-phase AC permanent magnetic synchronous motors (PMSMs) was developed years ago and is now being applied in industry. Implementations use hardware to measure two motor phase currents for current control and flux observation, and the sensors required to do this put a lower limit on cost. This paper presents a study and investigation of a one-shunt current detection (OSCD) approach that makes SVC less expensive. The complete and unique motor phase current reconstruction method was developed and implemented using low-cost but highly integrated and high-performance Renesas SH7080 microcontroller (MCU). To enable a comparison of its control system performance, an SVC control design that used LEM current sensors was also built. Dynamometer tests revealed that the OSCD design provided high levels of steady-state and dynamic performance, similar to those obtained with the LEM-based SVC design. The results demonstrated that SVC implemented with one-shunt current detection has great potential and practical significance for industrial applications.