High Frequency Injection Transient Disturbance Mitigation for Sensorless Control of Salient Pole Machines

Position sensorless operation of salient pole machines is a sought-after feature due to benefits such as increased reliability and reduced hardware costs. High frequency injection (HFI) schemes, exploiting rotor magnetic anisotropy, are typically applied to extract rotor position at low speeds. Normally, the injected high frequency component is not regulated in a closed-loop format to reduce control complexity. This can cause extended transients when HFI is enabled or disabled. In this paper, a compensation method is proposed to mitigate transition transients based on mathematical analysis of the machine model. The proposed compensation is verified via experimental data.