随着大规模直驱风电场并入弱交流电网,两者之间复杂的交互作用使得系统遭受扰动后的短期电压稳定问题愈发突出.如何在线准确分析扰动后直驱风电场并网系统的短期电压稳定性是一个关键性挑战.为此提出一种基于广义瞬时能量函数法的短期电压稳定性分析方法.首先,建立了锁相环dq坐标系下的直驱风电场并网系统的动态模型.然后,根据无功守恒原理构造出直驱风电场并网系统的广义瞬时能量函数.基于广义瞬时能量函数提出动态无功能量安全域(dynamic reactive power energy security regions,DRPESR)来在线评估系统的短期电压稳定性.利用构造出的分层能量结构来分析直驱风电场并网系统的短期电压失稳机理.最后,基于Matlab/Simulink的时域仿真结果,证明了广义瞬时能量函数的有效性和所提判据的准确性.
Analysis of short-term voltage stability of a large-scale direct-drive wind farm integrated into a weak AC grid based on the generalized instantaneous energy function method
With the integration of large-scale direct-drive wind farms into weak AC grids,the complex interactions between the two make the short-term voltage stability problem of the system after perturbation more and more prominent.How to accurately analyze the short-term voltage stability of the grid-connected system of direct-drive wind farms after disturbances online is a key challenge.To this end,a short-term voltage stability analysis method based on the generalized instantaneous energy function method is proposed.First,a dynamic model of the grid-connected system of direct-drive wind farms in the phase-locked loop dq coordinate system is established.Then,the generalized instantaneous energy function of the grid-connected system of direct-drive wind farm is constructed according to the principle of reactive power conservation.Based on the generalized instantaneous energy function,dynamic reactive power energy security regions(DRPESR)are proposed to evaluate the short-term voltage stability of the system online.A hierarchical energy structure is constructed to analyze the short-term voltage destabilization mechanism of the grid-connected system of direct-drive wind farms.Finally,the time-domain simulation results based on Matlab/Simulink demonstrate the validity of the generalized instantaneous energy function and the accuracy of the proposed criterion.
direct-drive wind farmsweak AC power gridshort-term voltage stabilityenergy function
万方数据
维普
