MTPA Control of Sensorless IPMSM Drive System Based on Virtual and Actual High-Frequency Signal Injection

In this article, a new method of virtual and actual signal injection (VASI) is proposed to realize the sensorless control and the maximum torque per ampere (MTPA) control simultaneously at the low-speed region. Sensorless control is realized by injecting a high-frequency signal in the third-harmonic space, and the MTPA control is achieved by virtual signal injection (VSI-MTPA) in the fundamental space. Due to inherent decoupling of these two spaces, the injected two signals are decoupled with each other. It means that the two control algorithms guarantee the requirements of control accuracy based on simultaneous realization. In general, the proposed method makes full use of the advantages that the MTPA control based on virtual signal injection will not cause additional loss to the system and the feature of five-phase interior permanent magnet synchronous motor dual-space decoupling. Besides, this method is used to save the cost of the encoder and achieve high-efficiency control of the motor and easy to be implemented. The feasibility of the proposed control scheme is verified through experimental results.