地区电网N-1校验中小干扰稳定的快速估算

Fast estimation of small disturbance stability for N-1 verification of regional power system

针对电力系统N-1校验中小干扰稳定分析计算需求较大的现状,尝试一种可用于地区电网在线分析的快速算法。将表征系统稳定性的特征根表达为支路参数的非线性函数,并由泰勒展开式近似估算任一支路开断后的特征根变化量指标,依据指标选取需准确计算的开断支路集,并准确计算。以特征根对导纳系数的灵敏度代替对实际导纳的灵敏度,简化了计算。所提算法能够通过一次完整的特征根灵敏度计算得到所有N-1下的指标。所提算法在2个算例系统上进行了试算和分析。

Since the small disturbance stability analysis for N-1 verification of power system has heavier computational load,a fast estimation approach suitable for the online analysis of regional grid is proposed. The critical eigenvalues describing system stability are analytically expressed as the nonlinear functions of line parameters and the eigenvalue variation of cut-off branch is estimated with Taylor expansions. The cut-off branch which needs accurate calculation is determined according to the eigenvalue variation and its eigenvalue is then calculated accurately. The sensitivity of eigenvalue to real admittance is replaced by that to admittance coefficient,which simplifies the calculation. All indexes of N-1 verification are obtained by one complete eigenvalue sensitivity calculation. The proposed approach is applied to two test systems.