Differential Model-Based Parameter Estimation of IPMSMs From Multi-State Measurements

Accurate parameter estimations are essential for efficient operation and high performance of interior permanent magnet synchronous machines (IPMSMs). Voltage source inverter (VSI) nonlinearity can adversely affect parameter estimation in IPMSM drive systems. Cross influence can compromise the accuracy of parameter estimation. This article proposes a differential model-based decoupling scheme to eliminate VSI nonlinearity effects and cross influence for accurately estimating key IPMSM parameters, including permanent magnet (PM) flux linkage, winding resistance, and machine inductances. The adverse effect of measurement noise and observational error on parameter estimation can be reduced in the proposed differential model. Utilizing the decoupling scheme, each parameter is estimated individually with high efficiency and accuracy leveraging the least square algorithm. The proposed differential model-based decoupling scheme is particularly well-suited for accurately estimating parameters over a wide speed range and diverse load conditions. The estimated parameters can improve the accuracy of predicting electromagnetic torque. Furthermore, the proposed method is noninvasive, robust, and does not require extra signal injection.