电力弹簧改进下垂控制策略研究

Research on Improving Droop Control Strategy of Electric Spring

LCL-ES是一种新型的需求侧管理方法,可以有效解决可再生能源大规模并网时造成的电压波动等问题。然而,当电网包含多个连接在不同节点上的LCL-ES时,由于线路阻抗的存在,节点间会发生压降。若相邻的两个LCL-ES给定的参考电压相同,会导致节点电压反复波动或者其中一组LCL-ES失控。为了解决上述问题,首先提出针对多个LCL-ES的下垂控制策略,该控制策略允许LCL-ES根据所在位置自动调节电压基准。由于传统的下垂控制无法合理分配无功功率,为进一步优化多个LCL-ES在调节电压过程中的无功出力,防止单个LCL-ES过载,利用局部一致性算法获得LCL-ES的无功信息,通过无功功率构建自适应虚拟阻抗,提高无功功率分配精度,并且增加电压补偿环节,补偿虚拟阻抗产生的压降。最后,在MATLAB/Simulink平台上通过仿真验证了所设计控制系统的有效性。

LCL-ES is a novel demand-side management approach that effectively addresses voltage fluctuation issues caused by large-scale integration of renewable energy sources.However,when the grid consists of multiple LCL-ES units connected at different nodes,voltage drops occur due to line impedance.If adjacent LCL-ES units have the same reference voltage,it can result in repetitive voltage fluctuations between nodes or the loss of control in one group of LCL-ES units.To address these issues,a droop control strategy is proposed for multiple LCL-ES units,allowing automatic voltage adjustment based on their locations.Traditional droop control cannot allocate reactive power adequately.To further optimize reactive power output during voltage regulation and prevent individual LCL-ES units from overloading,a local consensus algorithm is utilized to obtain reactive power information of LCL-ES units.An adaptive virtual impedance is constructed based on reactive power to enhance reactive power allocation accuracy.Additionally,a voltage compensation component is introduced to mitigate voltage drops caused by the virtual impedance.Finally,the effectiveness of the proposed control system is verified through simulations conducted on the MATLAB/Simulink platform.