부산대학교 도서관

The high-frequency (HF) injection technique is a pivotal method for estimating the rotor position of permanent magnet synchronous motors in the low-speed region. However, the conventional single-frequency HF voltage injection approach will induce pronounced noise and even cause Electro Magnetic Compatibility (EMC) issues. To address this issue, a random high-frequency (RHF) square wave injection technique is proposed in this paper, which broadens the power spectral density (PSD) and eliminates sharp noise by combining multiple frequencies. In the signal processing process, a filterless signal separation strategy is adopted to extract the fundamental and HF components of currents so as to improve system bandwidth. An innovative demodulation strategy is also proposed, and a linear extended state observer (ESO) is designed according to the mechanical equations of an interior permanent magnet synchronous motor (IPMSM) to determine the rotor position and speed. In conclusion, the feasibility of the scheme is verified by a series of simulation experiments.