设计了一种具有零稳态误差的并网逆变器系统,系统控制器由比例调节器P和谐振调节器R组成。与传统的PI控制器比较,该比例谐振控制器(PR)在基波频率处增益无穷大,因此可以完全消除稳态误差。通过理论分析,系统中采用了一种更易实现的准谐振控制器,并给出控制器参数具体的设计方法。此外,为了消除电网电压畸变或扰动对逆变器输出电流的影响,系统中引入了电网电压前馈解耦控制,改善了系统输出电流的质量。理论分析和实验结果验证了系统具有较好的稳态性能和抗扰性能。
A novel grid-connected inverter system with zero steady-state error is developed in this paper. The controller consists of a proportional regulator and a new type of resonant regulator. Compared with traditional PI control methods, the P+Resonant(PR) control can introduce an infinite gain at the fundamental frequency and hence can achieve zero steady-state error. A more practical quasi-PR controller is used and a step by step design procedure is proposed based on theoretical analysis. Besides, in order to eliminate the effect of grid voltage distortion or disturbance on output current, decoupling control is employed to further improve the quality of output current. Theoretical analysis and experimental results of an experimental prototype verified the high performance of the proposed system in both the sinusoidal reference tracking and the disturbance rejection.