U-Cell拓扑并网逆变器的MPC策略

针对七电平U-Cell拓扑并网逆变器的优化控制问题,设计了模型预测控制(MPC)策略。不同于传统并网逆变器系统,新型基于U-Cell拓扑的并网逆变器具有一个独立直流源和一组电容作为辅助直流回路,故能实现多目标控制的MPC方案应用于此具有明显优势,其通过对辅助电容电压的控制可实现七电平电压输出,同时控制逆变器在并网点提供所需的有功和无功功率,并保证电能质量。利用U-Cell拓扑逆变器样机进行了相关实验,实验结果表明,在直流电压、功率变化和功率因数变化下,系统均具有快速且准确的动态响应。

Model Predictive Control Strategy for the U-Cell Topology Grid-connected Inverter

A model predictive control(MPC)strategy was designed for the optimal control of a seven-level U-Cell topology grid-connected inverter.Unlike traditional grid-connected inverter system,the new U-Cell topology-based grid-connected inverter has an independent DC source and a set of capacitors as auxiliary DC loop.Therefore,the MPC scheme capable of achieving multi-target control has obvious advantages,and the seven-level voltage output can be realized by controlling the auxiliary capacitor voltage,and the inverter is controlled to provide the required active and reactive power in accordance with the power quality requirements at the grid connection point.The experiments were carried out with U-Cell topology inverter prototype.The experimental results show that the system has fast and accurate dynamic response under DC voltage,power variation and power factor variation.