基于多功能光伏并网逆变器的电能质量调节系统

摘要

In view of the power qulity problems , such as harmonics , reactive power and unbalanced current at point of common coupling of a distributed grid , a compound control strategy of photovoltaic grid-connected generation and pow-er quality regulation function based on LCL filter is proposed in this paper .The multi-functional inverter can inject ac-tive power into the distributed grid and and compensate the harmonics , load reactive power , and three-phase unbal-anced current in the grid-connected site .So it can improve the power quality and decrease the hardware investment . In addition, it gives an algorithm with no phase-locked loop, and designs a grid-current tracker with current weighted . In the end, the feasibility and effectiveness of the relevant design is verified by PSCAD /EMTDC.%针对分布式电网公共连接点处出现的谐波、无功和不平衡电流等电能质量问题，提出一种基于LCL滤波器的光伏并网发电与电能质量改善的复合控制策略，可以使多功能逆变器同时实现向分布式电网注入有功功率和对并网点处的谐波、负载无功、三相不平衡电流进行补偿。最大程度利用逆变器的硬件资源，减少硬件投入和设备体积，而达到改善公共连接点处电能质量的综合效果。并给出了一种无锁相环指令电流的生成算法，运用加权电流反馈控制设计了其并网电流跟踪器。最后，利用PSCAD／EMTDC验证了相关设计的可行性和有效性。