基于电网扰动暂态响应分析的虚拟同步机黑箱建模

Black-box Modeling of Virtual Synchronous Generator Based on Transient Response Analysis Under Grid Disturbances

建模和仿真是研究储能系统控制应用的重要工具。针对储能变流器的虚拟同步机(virtualsynchronousgenerator,VSG)控制,提出了一种基于电网扰动暂态响应分析的黑箱建模方法。首先基于VSG二阶非线性模型及其在工作点附近的小信号摄动处理,分析电网运行条件和功率指令对黑箱参数的影响,由此确定了黑箱参数MPf辨识采用输出误差(outputerror,OE)模型,黑箱参数MQU辨识采用多中心(polytopic)模型,进一步分析了OE模型的适用条件,并给出了辨识和建模流程。然后通过电网扰动激励出功率振荡模态信息,利用最小二乘法辨识黑箱参数。最后根据实验数据建立了VSG黑箱模型并且验证了模型的有效性,同时在Matlab/Simulink里搭建仿真模型,通过对比详细仿真模型和黑箱模型的仿真速度与存储空间,验证了黑箱模型适用于系统层对大规模储能系统的仿真分析。

Modeling and simulation are powerful tools to study on the control application of the energy storage system.For the control of the virtual synchronous generator(VSG)of the energy storage inverter,this paper proposes a black-box modeling method based on the transient response analysis under the grid disturbances.Firstly,based on the second-order nonlinear model of VSG and its small signal perturbation processing ability near the working point,the influence of the grid operation conditions and the power instructions on the black-box parameters is analyzed,and it confirms that the Output Error(OE)model is adopted to identify the MPf while the Polytopic model is adopted to identify the MQU.Furthermore,the suitable conditions for OE model are analyzed and the identification and modeling process are presented.Using the frequency and voltage step disturbances,the modal information on power oscillation of VSG is energized,and then the least-square method is utilized to estimate the parameters.Finally,the black-box model is built with the experimental measurements and the effectiveness of the model is verified.Meanwhile,the simulation speed and storage space of the black-box model are compared with that of the detailed simulation model in Matlab/Simulink to ensure its applicability for system-level simulation and analysis.