DC-link oscillation suppression method based on q-axis voltage compensation of a 180 kW PMSM traction system for urban rail transit

Abstract

Under certain working conditions, the permanent magnet synchronous motor (PMSM) traction system of urban rail transit shows negative impedance characteristics, which is easy to cause voltage resonance of DC-link and lead to instability of the system. In order to ensure the stability of the system, a DC-link oscillation suppression method based on q-axis voltage compensation is proposed. Firstly, the PMSM traction system and oscillation mechanism of DC-link are analyzed. Secondly, a stable control method based on q-axis feedforward decoupling voltage compensation is adopted to realize the decoupling control of PMSM and the suppression of DC-link oscillation. Finally, the method is verified on a 180 kW PMSM traction system, simulation and experiment verify the effectiveness of the DC-link oscillation suppression method.

Keywords

• PMSM
• Oscillation suppression
• Traction system
• Urban rail transit