基于VMD和MPC的电动汽车-火电机组联合调频控制

Combined frequency regulation control of electric vehicles and thermal power units based on VMD and MPC

合理的调频指令分配策略以及有效的指令跟踪控制方法是利用集群电动汽车(aggregate electric vehicle,AEV)联合火电机组开展调频控制、改善调频质量、提高调频经济性的关键。基于此,文中提出基于变分模态分解(variational mode decomposition,VMD)和双层模型预测控制(model predictive control,MPC)的AEV参与系统调频控制策略。首先,设计AEV联合传统火电机组的频率协调优化控制结构,建立火电机组及负荷频率控制模型,同时将AEV转化为虚拟调频单元,构建在AEV参与下系统单区域多机组负荷频率控制模型;然后,利用VMD将电网调频指令信号分解为含不同频率成分的本征模态函数,整合高频分量作为AEV的调频指令,低频分量作为火电机组群的调频指令,并通过双层MPC分别在AEV和火电机组群内部实现调频指令的优化再分配及跟踪控制;最后,对所提控制策略进行仿真验证。结果表明所提控制策略可实现对系统频率的有效调节,且兼顾了调频的经济性和动态性能。

Reasonable signal allocation strategy and effective signal tracking control method are the keys to using aggregate electric vehicles(AEVs)combined with thermal power units to perform the control,improve the quality,and enhance the economy in frequency regulation.Therefore,a frequency regulation control strategy with the participation of AEVs is proposed based on variational mode decomposition(VMD)and double-layer model predictive control(MPC).Firstly,the coordinated optimization control structure of AEVs combined with traditional thermal power units is designed for frequency regulation.The models for thermal power units and load frequency control are established.The AEVs are converted into virtual frequency regulation units,and the load frequency control model of single-area multi-unit with the participation of AEV is constructed.Then,the frequency regulation signal is decomposed into intrinsic mode functions with different frequency components using VMD.The high-frequency components and the low-frequency components are integrated as the frequency regulation signals of AEVs and thermal power units respectively.Optimal redistribution and tracking control of frequency regulation signals within AEVs and thermal power units are realized by double-layer MPC,respectively.Finally,the proposed control strategy is verified by the simulations,and the results show that it can adjust the system frequency effectively and keep a balance between the economy and dynamic performance in frequency regulation.