单相光伏并网逆变器的研究

Study on single-phase photovoltaic grid-connected inverter system

介绍了单相并网逆变器的软硬件控制回路,包括两级式单相光伏系统拓扑结构和最大功率跟踪功能,以及反孤岛效应等功能,并网逆变器的输出控制为电压源系统,保证输入的直流电压尽可能快地进行调整,实现对光伏阵列的MPPT控制,MPPT采用固定参数法与扰动观察法相结合的复合控制算法。孤岛效应检测采用了基于电网非特征次谐波阻抗的主被动相结合的检测方法。并在此基础上以TMS320F2406和IPM为硬件核心,研制出了5kW的实用化产品样机,现场运行结果表明所提出的控制方案具有良好的动态和稳态性能。

The paper introduces the software and hardware of single phase grid connected inverter control circuit,comprising of the single-phase photovoltaic system topological structure and maximum power point tracking func-tion, as well as anti-islanding effect function. The grid-connected inverter output control for voltage source system guarantees the input DC voltage is adjustable as quick as possible, and implements photovoltaic array MPPT control. The MPPT uses a combined control algorithm of fixed parameter method and perturbation and observation method. Islanding detection method is based on non characteristic harmonic impedance of power system active passive com- bined detection method. And on this basis, using TMS320F2406 and IPM as the hardware core, a 5kW practical product prototype is developed. Test results show that the proposed control scheme has good dynamic and steady state performance. Comparing the LCL filter with the L filter, we found that LCL filter is better.