Active torsional vibration suppression of integrated electric drive system based on optimal harmonic current instruction analytic calculation method

Abstract

Torque fluctuation caused by flux harmonics in a permanent magnet synchronous motor (PMSM) leads to torsional vibrations in vehicle-integrated electric drive systems. To resolve this fluctuation, the coupling relationship between the torque fluctuation and harmonic current of the PMSM was analyzed by establishing an analytical model of the instantaneous torque of the PMSM. The analysis was performed considering the harmonic and saturation characteristics of the flux chain. An analytical calculation method for the reference harmonic-current instruction was proposed to suppress torque fluctuation. The proportional integral resonant (PIR) controller was designed to accurately control the actual current to follow the reference harmonic-current command. Thus, an active torsional vibration suppression method was developed. Simulation and experimental results showed that the proposed method can effectively reduce the amplitude of the 6th and 12th harmonic torque of the PMSM. The amplitude of each axis torque and gear-meshing force, corresponding to the harmonic frequency of the transmission system, is considerably reduced. The transmission stability is also significantly improved.