An Improved Pulsating High Frequency Injection Sensorless Control Strategy Based on Dual Multi-Parameter Notch Filter and Rotor Estimated Position Compensation

The position-speed observation loop constructed by the conventional pulsating high-frequency injection method is contradictory in terms of both high-order harmonic suppression and observation performance. Meanwhile, the phase delay caused by the low-pass filter (LPF) in the position observation loop also seriously affects the load carrying capacity of the motor. In order to widen the observation bandwidth of the position-speed observation loop and weaken the negative influence of the LPF on the position-speed observation loop, this paper proposes an improved positionless control strategy based on the dual multi-parameter notch filter (DMPNF). Compared with the traditional notch filter, the DMPNF used in this method weakens the degree of coupling between different performance metrics, which can simplify the design process and at the same time improve the performance of the designed notch filter. This method has a wider stabilized observation range and is able to use a higher loop gain than the conventional method, while maintaining a strong suppression effect on the higher harmonics. Meanwhile, the dynamic performance of the position-speed observation loop is further improved by estimating the position compensation. In this paper, the conventional pulsating high-frequency injection method is first modeled and analyzed. Then, the proposed improved sensorless control strategy and observation position error compensation method are analyzed and presented. Finally, the effectiveness of the proposed method is verified by simulation.