Design and performance analysis of inverter systems based on state-space identification

Against the backdrop of the booming development of new-energy power generation and smart grids, power-electronic transformers exhibit broad application prospects due to their unique advantages. Based on the DC-AC topology, this work constructs an inverter control system model founded on state-space system identification. The sinusoidal pulse-width modulation (SPWM) strategy is employed to drive the operation of power-electronic transformers. A single-phase full-bridge inverter with a dual-closed-loop control system, consisting of an inductor-current inner loop and an instantaneous-voltage outer loop, is successfully implemented. The state-space system identification method is utilized to optimize the proportional-integral (PI) parameters, and a load-mutation test is introduced. The reliability of the control strategy is verified by the total harmonic distortion (THD) parameter. Simulation results indicate that the closed-loop control strategy, combined with the PI parameters identified through the state-space system, significantly enhances the output voltage regulation accuracy and the stability of the control system, providing strong support for the efficient application of power-electronic transformers in the new-energy field.