Enhancing Grid Integration and Design of Low Speed PMSGs by Exploiting SRF-PLL-Based Sensorless Control and Holistic Modeling

This article proposes a holistic co-design framework with a low-cost approach for a permanent magnet synchronous generator (PMSG) that enables to optimizes both the electromagnetic and mechanical design, in conjunction with the injection of the maximum available power towards the power grid through a controlled electronic back-to-back converter. The proposed sensorless controller includes a hybrid PLL with a dynamically adjustable tabulated gains system and a feedforward frequency estimator. These add-ons allow to precisely track the speed and angle of the rotor shaft for near-zero speeds. This methodology includes the development of analytical models for the structural, magnetic and electrical components. The efficiency and performance of the machine and controller is verified by simulation under different load conditions and high angular speed variability of a 1.5 kW scale prototype in JMAG and Matlab & Simulink™ environments, reaching an efficiency of 80%.