Online Compensation of Current Measurement Errors in DPCC for SPMSM Drives Using an Error-Type-Specific Adaptive Disturbance Observer

Current sensor offset and scaling errors degrade the current regulation accuracy and torque performance of predictive current control in permanent magnet synchronous motor (PMSM) drives. Since the two error types exhibit different signal structures, simultaneous online compensation remains difficult for existing methods. This paper proposes an adaptive disturbance-observer-based current sensor error compensation method for PMSM drives. A unified error model is established to show that offset errors behave as constant or slowly varying terms, whereas scaling errors appear as rotor-position-dependent periodic disturbances. Based on this difference, an adaptive observer with error-type-specific update laws is developed, where an integral-type law is used for offset estimation and a rotorsynchronized law is adopted for scaling estimation. In addition, a composite current control structure combining deadbeat predictive current control and a PI regulator is designed to reduce the contamination of the estimation channel by parameter mismatches and inverter nonlinearities. The observer error system is proven to be uniformly ultimately bounded. Experimental results under steady-state, dynamic, and parameter-mismatch conditions verify that the proposed method reduces current ripple and phase-current harmonic distortion while enabling direct online compensation without multi-stage signal injection.