基于模型预测控制的光储发电系统VSG频率控制方法  

VSG Frequency Control Method of Photovoltaic System With Storage Based on Model Predictive Control

作　　者：李帅虎 胡耀尹 罗滇生[3] 张志丹 LI Shuaihu;HU Yaoyin;LUO Diansheng;ZHANG Zhidan(School of Electrical&Information Engineering,Changsha University of Science and Technology,Changsha 410114,Hunan Province,China;School of Automation and Electronic Information,Xiangtan University,Xiangtan 410015,Hunan Province,China;School of Electrical&Information Engineering,Hunan University,Changsha 410082,Hunan Province,China;Electric Power Research Institute,State Grid Hunan Electric Power Company,Changsha 410004,Hunan Province,China)

机构地区：[1]长沙理工大学电气与信息工程学院,湖南省长沙市410114 [2]湘潭大学自动化与电子信息学院,湖南省湘潭市410015 [3]湖南大学电气与信息工程学院,湖南省长沙市410082 [4]国网湖南省电力公司电力科学研究院,湖南省长沙市410004

出　　处：《全球能源互联网》2022年第4期348-355,共8页Journal of Global Energy Interconnection

基　　金：国家自然科学基金(51777179);国网湖南省电力有限公司科技项目(5216A521003C)。

摘　　要：随着光伏发电装机规模大幅提升,电力系统转动惯量不断降低,虚拟同步发电机(virtual synchronous generator,VSG)技术被广泛采用以应对日益严峻的电网稳定性问题。为进一步提高VSG技术对系统稳定性的改善作用,提出基于模型预测控制的VSG频率控制方法。该方法首先在同步发电机转子运动方程和逆变器下垂控制方程基础上建立VSG可优化的离散模型,再通过模型预测控制(model predictive control,MPC)预测VSG转子角频率的运动轨迹,并将最优的预测控制输入向量的第一项作为下一时刻控制器的反馈输入。将VSG转子角频率增量转化为转矩增量的反馈回路,实现对频率偏差的实时预测补偿,提升VSG并网逆变器的无差调频能力和运行性能。最后,在MATLAB软件上搭建含光储系统的时域仿真模型,验证了所提方法能更有效地抑制频率越限,减少系统频率的恢复时间。Under the national“dual carbon”goal,the installed scale of distributed photovoltaic power generation will be greatly increased.But photovoltaic grid-connected inverters provide almost no moment of inertia to the grid,which could cause severe stability of the grid.In this context,virtual synchronous generator(VSG)technology is widely considered to be introduced into photovoltaic grid-connected systems.In order to further improve the effect of VSG technology,this paper proposes a model predictive control method for improving the frequency response of the VSG.In this method,the photovoltaic grid-connected adopts a two-stage structure to realize grid-connected power control,and the energy storage inverter realizes a voltage-based VSG control strategy.This method first establishes an optimizable VSG model through the rotor motion equation and the droop control equation,and discretizes the model,then uses model predictive control(MPC)to obtain the rotor angular frequency motion trajectory,and takes the first term of the optimal predictive control input vector as the feedback input of the controller at the next moment.Then,through the built feedback channel between the rotor angular frequency increment and the torque increment,the frequency deviation is predicted and compensated in real time,and the secondary frequency modulation capability and operating performance of the VSG grid-connected inverter are improved.At the same time,by analyzing the influence of feedback controller parameters on system stability,the basic principles of parameter selection are given.Finally,based on the simulation model of the grid-connected inverter with optical storage built by MATLAB,the simulation results show that the method proposed in this paper can more effectively restrain the frequency limit and reduce the frequency recovery time,which verifies the effectiveness and feasibility of the method.

关 键 词：光储发电系统 虚拟同步发电机 模型预测控制 二次调频 

分 类 号：TM341[电气工程—电机] TM615