Online Multiparameter Estimation with Position Error Correction for Unified Synchronous Machine Sensorless Drives

Parameters’ accuracies are essential for model-based sensorless control in synchronous machine drives. In this paper, a multiparameter adaptive observer and a position error optimizer are presented to obtain real-time parameter information in the absence of rotor position data for unified synchronous machine (SM). The adaptive observer is based on the misaligned dq-axes’ small-signal impedance model where dq-axes EMF coupling terms are well considered. All parameters can achieve high accuracy under entire operation region. In the case of isotropic SMs, the estimated parameters can be directly utilized in the model-based observer to acquire high precision position observation. And, for anisotropic SMs, an optimizer is introduced to correct parameter inaccuracies caused by position error. The effectiveness of the proposed adaptive observer and optimizer is evaluated through a combination of experiments and simulations, providing comprehensive validation of their performance. ¹