부산대학교 도서관

In the grid-connected inverter controller system, conventional PI or PR controller decrease their lowfrequency gain and bandwidth to maintain the stability of the system. However, this degrades the disturbance rejection and current tracking capability. To solve this problem, this paper gives an H∞ robust control scheme based on Numerator Denominator Model method, which has the advantages of simplified current controller design procedure, can place the poles of closed-loop system at the desired place. By properly selecting the weight function, the proposed control scheme can not only achieve good robustness in disturbance rejection capability, but also gives a straight forward to design the dynamic performance. Simulation and experimental comparison results between PR and H∞ controller is demonstrated. The results prove that the proposed control scheme shows obviously improvements on the robustness of inverter and meanwhile does not lose advantages on the dynamic performance.