A Combined Compensation Strategy for Steady-State Performance Improvement of Proportional-Proportional-Delay Controller

Abstract

Within control system architectures, the proportional-proportional-delay (PPD) controller is theoretically characterized by enhanced dynamic responsiveness, a streamlined control structure, and reduced computational demands. Nevertheless, this control strategy demonstrates heightened dependence on system model accuracy coupled with compromised robustness, thus imposing significant constraints on its practical deployment in industrial control scenarios. To improve steady-state control performance of the PPD controller against circuit parameters variations, this paper investigates quantity relationships between circuit parameters variations and grid current amplitude changes first, and a dominant factor and some minor factors affecting the grid current are found out successfully. As a result, linear control of the PPD controller against model parameters changes has been proposed based on a linear function. Meanwhile, an integral controller composed has been integrated into the control strategy to eliminate the residual steady-state error of the proposed linear controller. Finally, a combined control structure with both linear and integral controllers has been proposed, and experimental results have been presented to verify the correctness and effectiveness of the combined control.