基于递推最小二乘法的虚拟同步发电机参数辨识方法

摘要

基于虚拟同步发电机 (VSG) 控制的逆变器能够为微网提供惯性和阻尼, 提出一种VSG参数辨识方法, 为微网的优化设计提供基础.首先建立了VSG输出功率对指令功率的二阶传递函数模型, 然后根据基于VSG控制的逆变器在响应阶跃指令功率后的输出, 利用模型参数与惯性和阻尼系数的关系, 并基于递推最小二乘法辨识出逆变器提供的惯性和阻尼系数.进一步分析了稳态平衡点偏移以及双线性变换给辨识结果带来的误差, 结果表明利用递推最小二乘法辨识VSG参数能够满足一定的精度要求.最后, 通过MATLAB仿真和实验验证了所提参数辨识方法的可行性和有效性.%The inverters controlled by virtual synchronous generator (VSG) can provide inertia and damping for microgrids.A method for identifying the parameters of VSG is proposed to provide the basis for the optimal design of microgrids.Firstly, a second-order transfer function model of VSG's active power output to command power is proposed.Secondly, according to the active power response of VSG-controlled inverter to the command power, and the mathematical relationship between transfer function parameters and inertia and damping coefficients, the inertia and damping coefficients of the inverter are identified by using the recursive least squares algorithm.Meanwhile, the errors caused by steady state equilibrium shift and the bilinear transformation on the identification results are analyzed, which shows that the parameter identification of VSG by using the recursive least squares algorithm can satisfy a certain accuracy requirement.Finally, the feasibility and effectiveness of the proposed method are verified by simulations with MATLAB and experiments.