Abstract: High frequency (HF) signal injection is commonly used in permanent magnet synchronous motor (PMSM) sensorless drives at low speeds and standstill. However, the extra acoustic noises caused by additional signal injection impose restrictions on its further applications. To address this issue, a pulse voltage injection based sensorless control scheme was proposed to attenuate HF noises. Based on the overall control performance of the drive system, the form of injected pulse signals was designed, together with the corresponding position signal demodulation via performing current difference operation twice. In order to tackle the problem of low accuracy and obvious ripple of the estimated position caused by low update frequency of position orthogonal signals, a position observation accuracy improvement strategy based on quadratic interpolation filtering was proposed to effectively suppress the HF ripple without filters. The validity and effectiveness of the proposed scheme are verified on a 2.2kW PMSM platform.