Single-phase Synchronous Inverter with Overcurrent Protection using Current Controller with Latched Limit Strategy

This paper proposes a controller for single-phase synchronous inverters (SSIs) that was designed to stabilize the performance of a grid while providing overcurrent protection during the occurrence of a fault. The proposed controller for an SSI eliminates the multiple feedback control loops consisting of voltage and current controllers under normal conditions to avoid the instability attributed to them. To output the designed voltage precisely calculated using the core circuit, including a swing equation and speed governor, we employ the latched limit strategy for the overcurrent protection, which is combined with a proportional resonance current controller. Numerical simulations and experiments demonstrated that the proposed controller provides the designed performance while ensuring overcurrent protection during normal operation. (c) 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.