Simple and low-cost motion-sensorless control approach for the IPMSM with elimination of DC offset and steady-state error

Abstract

Voltage type flux observer has attracted much attention because of its less mathematical calculations and ease of implementation. The only issue with the flux estimation approach is the integration mechanism; using a pure integrator may cause integrator saturation and a DC bias issue, whereas using the low pass filter (LPF) and a self-adaptive band-pass filter (SABPF) would result in magnitude and phase angle errors. This work offers an improved flux linkage estimation approach with a proportional integral (PI) DC offset compensator, resolving the DC drift issue associated with the observer’s pure integrator. Compared to the standard voltage type flux observer, the DC offset is removed, the LPF and phase adjustment are eliminated, and low-speed armature position estimate accuracy is improved. The proposed method can reduce calculation. As a result, the control period is reduced. The Matlab Simulink framework findings are presented to validate the performance and effectiveness of the proposed strategy.