Current Sensorless MTPA for IPMSM Drives

In this paper, a maximum torque per ampere (MTPA) control strategy is presented for interior permanent magnet synchronous machines (IPMSMs) without current sensing or regulation. The developed control scheme achieves MTPA using a direct voltage control method, which varies the machine's stator voltage amplitude and angle. As such, no explicit current loop regulation is needed, which simplifies the control structure and unlike other control strategies, no parameter knowledge, voltage, or current transducer is required. Experimental comparison against the well-known MTPA vector control highlights the performance of the proposed controller in various conditions. Moreover, quantitative efficiency metrics are provided to better illustrate the MTPA trajectory tracking performance. Furthermore, the simplicity of the control scheme makes it a good candidate for low-cost implementation of real-time IPMSM drives.