基于储能协调自适应VSG控制策略研究

RESEARCH ON ADAPTIVE VSG CONTROL STRATEGY BASED ON ENERGY STORAGE COORDINATION

针对高比例可再生能源接入电网由于电力电子装置欠阻尼和惯量难以有效主动支撑系统频率的缺点,同时为了兼顾储能系统的稳定频率及功率调节的重要作用,提出基于储能协调的自适应虚拟同步机(VSG)控制策略。首先,建立VSG光储并网基本结构以及各模块单元控制基本结构。其次,对基于储能协调自适应旋转惯量和阻尼协调虚拟同步机控制策略进行设计,根据功角振荡特性曲线和转子角频率曲线,推导出旋转惯量和阻尼与频率变化之间的关系。同时通过直流侧储能DC/DC控制策略结合下垂特性耦合到交流侧虚拟同步机控制策略,将蓄电池荷电状态容量(SOC)的变化通过储能协调控制器生成VSG的部分有功参考值协调自适应旋转惯量J、阻尼D参与P-f调频,并对基于储能协调的自适应VSG控制策略动态性能进行分析。最后,建立基于储能协调自适应VSG光储微电网系统仿真模型。通过仿真验证了该方法的可行性,仿真结果表明:基于储能协调自适应VSG控制策略相比于常规自适应VSG控制策略,可充分发挥储能的作用,能更好地协调J、D自适应调节系统频率和稳定功率、抑制波动,提高系统的暂态性能。

In view of the disadvantages of high proportion of the underdamping of power electronic devices and the difficulty of inertia to effectively and actively support the system frequency when high proportion of renewable energy connected to the power grid,and in order to take into account the important role of stable frequency and power regulation of the energy storage system,an adaptive virtual synchronous generator(VSG)control strategy based on energy storage coordination is proposed in this paper.First of all,the basic structure of optical storage and grid connection of VSG and the basic control structure of each module unit are established.Secondly,the control strategy of virtual synchronous machine based on energy storage coordination adaptive rotating inertia and damping coordination is designed.According to the power angular vibration characteristic curve and rotor angular frequency curve,the relationship between rotating inertia and damping and frequency change is derived.The change of SOC capacity is used to generate the active reference value of VSG through energy storage coordination controller to coordinate J and D to participate in P-f frequency modulation.Meanwhile,the DC side energy storage DCDC control strategy combined with droop characteristics is coupled to the AC side VSG control strategy,and the dynamic performance of the adaptive VSG control strategy based on energy storage coordination is analyzed.Finally,an adaptive VSG optical storage microgrid system simulation model based on energy storage coordination is established.The feasibility of this method is verified by simulation experiments.The simulation results show that compared with the conventional adaptive VSG control strategy,the adaptive VSG control strategy based on energy storage coordination can give full play to the role of energy storage,better coordinate J and D to adaptively adjust the system frequency and stabilize power,suppress fluctuations,and improve the transient performance of the system.