Autonomous Sensorless Control Strategy for FP-PMSM Considering Operation Uncertainties with DCEE

The sliding mode observer (SMO) has been widely adopted in sensorless control system of the five-phase permanent magnet synchronous motor (FP-PMSM) due to its simple structure and strong robustness. However, the internal and external uncertainties of SMO-based sensorless control strategies degrade the sensorless control accuracy of FP-PMSM under varying operation conditions. Currently, most studies fail to simultaneously account for both internal and external uncertainties, which limits the improvement in the estimation accuracy under multiple operation conditions. In this study, an autonomous sensorless control strategy of FP-PMSM considering operation uncertainties with dual control for exploration and exploitation (DCEE) is innovatively developed. First, an N-dimensional q-axis inductance estimator is designed to quantify and mitigate the external uncertainty from varying operation conditions, which can overcome limitations of traditional parameter identification. Additionally, a new objective function is established to generate optimal sliding-mode gains under varying operation conditions, which can reduce the internal uncertainty of sensorless control system. Therefore, by selecting sliding-mode gain autonomously according to varying operation conditions, internal and external uncertainties can be effectively decreased, which can improve sensorless control accuracy. Finally, effective improvement in sensorless control accuracy of FP-PMSM under varying operation conditions is verified through experiments.