A Fixed Sampling-Vector Phase Shift Method for Acoustic Noise Reduction With One DC-link Current Sensor in Motor Control

Switching-state phase shift (SSPS) method is widely used in motor drive system with single DC-link current sensor (SDLCS) because of its advantages such as no additional hardware design requirements, low switching loss, and simplicity. However, SSPS produce significant current ripple and annoying acoustic noise, especially around low modulation regions. The main reason is that the phase shift mode of SSPS method is not continuous when the reference voltage vector passes the sector. In this paper, the current ripple caused by SSPS method is quantitatively analyzed, and a fixed sampling-vector phase shift (FSVPS) method is proposed. FSVPS has the same advantages as SSPS. Under the control of FSVPS, the current ripple moves away from the frequency band sensitive to human ears and adjusts to lower and higher frequency bands, thus improving the noise performance of SSPS. Simulations and experiments prove the effectiveness of this method, and the acoustic noise reduces to the same level as traditional three-current sensor (TCS) method.