基于安全域的电网最小切负荷计算方法

Minimum Load-shedding Calculation Approach Based on the Security Region in the Power Grid

提出一种基于安全域的电网紧急控制最小切负荷计算方法,将系统紧急控制的问题划分为恢复电压稳定和排除系统支路越限2个子问题。分别利用割集电压稳定域和有功静态安全域描述这2个子问题的约束,进而提出一种快速确定最小切负荷方案的节点对集的方法,其计算速度优于传统线性规划方法。该方法通过安全域边界的超平面描述确定对某条越限支路控制最有效的负荷节点和发电节点对,针对该节点对能计算出排除该线路越限的最小切负荷量。排除全部线路越限所需的节点对共同构成节点对集。IEEE39节点系统和中国河南系统的算例都表明了所提方法的有效性。

This paper proposes a minimum load-shedding calculation approach of emergency control based on the concept of security region. This approach divides the load-shedding problem into two sub-problems： one about restoring voltage stability and the other about restoring transmission line thermal stability. The static voltage stability region in cut-set space and the steady-state security region of real power are utilized to solve these two sub-problems. An approach based on the couple-node set is proposed to calculate the minimum load-shedding. The calculation speed of this approach exceeds that of the traditional linear programming. The couple-node for an overflowed branch consists of a load bus and a generator. Tuning the power injection of these buses is a most effective way to lower the power flow over the branch The couple-node set consists of the couple-nodes needed to remove all overflowed branches. The test results on the IEEE 39-bus system and Henan system in China indicate the effectiveness of the approach.