An MDCPR-Based Harmonic Observer for Position Estimation Improvement in Sensorless IPMSM Drives

Back electromotive force (EMF) estimation is a common model-based sensorless control strategy utilized for interior permanent magnet synchronous motor (IPMSM) control. However, the position estimation performance subjects to harmonic distortion and time delay effect, which will inevitably deteriorate the estimation accuracy and system reliability. For solving the issues, a novel multiple delay-compensated proportional resonant-based harmonic observer is proposed in this article. The proposed method, cascaded with sliding mode observer, is composed of multiple delay-compensated proportional resonants (DCPRs) to eliminate the specified harmonic components completely under severe distorted conditions. In addition, its internal delay compensation module is introduced to compensate the phase lag in back-EMF estimations caused by pulse width modulation (PWM) output delay effectively. Furthermore, the influence of the observer parameters is described in detail for excellent control performance. Finally, the intensive comparative experiments were carried out for validating the effectiveness and feasibility of the proposed sensorless strategy at a 1.5-kW IPMSM drive platform.