锂电池能量回收系统的进网电流优化控制技术

为了改善锂电池能量回收系统并入电网的电能质量,针对系统核心组成部分并网逆变器进行研究.通过建立基于LCL滤波器的并网逆变器的系统模型,说明该系统对控制方案所提出的要求,并指出传统的基于电网电压定向的PI控制方案无法在满足稳定性要求的同时实现良好的控制性能.引入一种重复控制与PI控制相结合的复合控制方案来弥补原有控制方案的不足.通过系统仿真以及样机实验证明,该方案对由电网电压畸变所引起的进网电流中的谐波成分具有较好的抑制能力,能够在不增加系统硬件复杂程度的前提下获得较好的进网电流波形.

Grid current regulation of grid-connected lithium battery power recovery system

In order to improve the quality of the feedback electrical power generated by lithium battery power recovery system, the grid-connected inverter is analyzed as the key component of the system. The limitation for control strategy is carried out by modeling the LCL filter based grid-connected inverter, which indicates that traditional voltage-oriented PI control is not able to guarantee stability and excellent performance of the system at the same time. According to the analysis, a control strategy combing repetitive control and PI control is adopted. The simulation and experimental results confirm that the compound control strategy is better at rejecting the current harmonics introduced by grid voltage distortion, and the grid current can be well regulated by this strategy without increasing hardware cost．