单相单级光伏系统的二次功率扰动抑制策略

Secondary power disturbance rejection strategy for single-phase single-stage PV system

传统单相单级光伏逆变器的二次功率扰动问题对光伏阵列的输出功率和逆变器的输出电能质量造成不利影响,在深入分析二次功率扰动的基础上,提出了基于二次功率解耦电路的新型逆变器拓扑结构,该拓扑通过增加一个控制自由度,将直流侧电容中的二次功率转移至电感元件。针对该新型逆变器的拓扑特点,构造出相应的调制方法及控制策略。分析证明,该新型单相单级逆变器能有效抑制二次功率扰动,进而抑制直流电压的二次纹波分量,提高光伏系统的效率和并网电流质量。仿真与实验结果验证了该新型逆变器拓扑结构及控制策略的合理性和有效性。

： The secondary power disturbances of traditional single-phase single-stage photovohaic （PV） inverter affect the output power of PV arrays and the output electrical energy quality of the inverter adversely. Based on deeply ana- lyzing the secondary power disturbances,a new inverter topology based on secondary power decoupling circuit is pro- posed in this article. In the new topology,through adding a control degree of freedom,the secondary power in the ca- pacitor on the DC side is transferred to the inductive element. According to the topology characteristics of the new in- verter, the modulation method and system control strategy of the new inverter are established. Analysis shows that the novel single-phase single-stage inverter can effectively suppress the secondary power disturbance, thereby suppress the secondary ripple component in the DC voltage,and improve the efficiency of the PV system and the quality of the grid connected current. The simulations and experiment results verify the rationality and effectiveness of the new in- verter topology and control strategy.