Principle and Stability Analysis of an Improved Self-Sensing Control Strategy for Surface-Mounted PMSM Drives Using Second-Order Generalized Integrators

For the purpose of avoiding the drawbacks of large volume, heavy weight, complex wiring, and low reliability caused by the mechanical position sensors in aeronautic power drives, the self-sensing control of permanent magnet synchronous machines (PMSMs) has been getting increasing attention. High-frequency (HF) pulsating current injection is an efficient method to obtain the rotor position at low speeds. However, in this method, the rotor position is extracted from the command voltage instead of the actual measurement due to the lack of voltage sensors, and the control performance of the HF current is nonideal because of the proportional-integral controller (PI) current regulators. Both these shortcomings give rise to position estimation error. To avoid the aforementioned problems, a novel current regulator consisting of the PI and second-order generalized integrator (SOGI) is presented. The different combinations of the PI and SOGI in the d-q axes current regulators are studied. The system stabilities of the proposed and existing HF pulsating current injection-based self-sensing control strategies are comparatively analyzed considering the current control error and some other aspects. The experimental results demonstrate the feasibility of the proposed strategy by a surface-mounted PMSM vector controlled system.