Search

To solve the performance degradation caused by current measurement error (CME) of 2LVSI-permanent magnet synchronous motor drive system, additional current sampling points, auxiliary equipment, or more computing resources are often required in existing CME calibration methods. To cope with these challenges, a calibration strategy with virtual viable sampling timing via continuous pulse width modulation (CPWM)-DPWM modulation mode switching is proposed. Additional current sampling points and sampling point movement are not required by flexibly switching modulation mode to discontinuous pulse width modulation (DPWM). Only current closed-loop feedback values at routine sampling point are required for the CME estimation without the reference current, complex observers, and filters. Therefore, the proposed method can be used as a solution for CME with low hardware dependency and low computing complexity. Meanwhile, the effectiveness and practicability of the proposed method are verified by the experiments, which shows that the CME can be well estimated and eliminated.

Dual permanent magnet synchronous motors (PMSMs) based electric powertrain has been widely used in electric vehicles. Torque ripple caused by current measurement errors has a huge impact on the performance of dual-PMSM based electric powertrain. Currently, the measurement errors of current sensors in a dual-PMSM system are individually calibrated results in inconsistent calibration standards. The inconsistent calibration for errors of current sensor affects the current distribution of dual-PMSM based electric powertrain, thus making the motors unable to output power based on the specified ratio. To unify the calibration standards of dual-PMSM subsystems, a fast calibration method with high reliability is proposed in this article. The proposed calibration method is able to: check the rationality of the compensation values to eliminate the wrong value in the sampling process, and calibrate within one second even under the conditions of load distribution, speed mutation, no-load, interference or noise. A 2 kW dual-PMSM based electric powertrain testing rig is employed to verify the effectiveness of proposed calibration method.