多运行方式下恢复交直流系统潮流可行域的控制策略

Control strategy of feasible region recovery for power flow of AC/DC system under multi-operating conditions

电力市场化后,电力系统将运行在更加接近稳定约束边界的状态。当系统按正常网架运行时,由节点负荷和发电机出力确定的运行方式随时都在变化,系统可能在某些运行方式下出现不满足稳定约束条件的情况。针对一系列预想故障,提出了一种多运行方式下交直流互联系统静态电压稳定的预防控制策略,以使系统在所有的运行方式下对N-1情况都运行在潮流可行域范围内。以潮流雅可比矩阵的最小模特征值确定系统的最严重预想故障,根据节点注入无功对最小模特征值的参与因子,挑选出在恢复潮流可行域的优化计算中需要切除负荷和调整发电机出力的节点,并配合调整直流变量恢复系统至可行域范围内。算例分析表明所提方法是有效的。

In power market,power system will operate under the conditions closer to its stability limits. During normal operation of power system, the operating conditions determined by nodal load and generator output change from time to time and the stability restrictions may sometimes be not satisfied. Aiming at a series of possible incidents,a preventive control strategy is proposed for the static voltage stability of AC/DC power system,which makes system always operating in feasible region of power flow under all operating conditions for N- 1 structure. The worst incident is determined by the minimum eigenvalue of Jacobian matrix. The participation factors of nodal injection to the minimum eigenvalue are used to select the nodes,of which the load or generator output will be cut or re- dispatched for feasible region recovery of power flow,together with the adjustment of DC variables. Case calculation shows its effectiveness.