计及静态电压稳定约束的交直流系统可用输电能力

Available Transfer Capability of Hybrid AC/DC Power System Considering Constraint of Static Voltage Stability

为考虑不同控制方式下直流系统对交流潮流的影响,采用顺序求解法计算交直流系统潮流时,对交流系统雅可比矩阵的特殊节点元素进行了有效修正。将电压稳定局部指标L进行合理简化,简化后的L指标能够避免电压相量复数运算,有效提高了计算速度。在简化的L指标基础上,提出了计及电压稳定性约束的交直流系统可用输电能力优化模型。采用非线性原–对偶于内点法对优化模型进行求解,通过计算L指标研究不同的电压稳定裕度对系统可用输电能力和电压稳定性的影响。算例结果验证了简化L指标的合理性和优化模型的有效性。

To analyze the influence of DC power system on AC power flow under various control modes, when the power flows in AC and DC system are calculated by sequential solution, the elements of special nodes in Jacobian matrix of AC system are effectively modified. The local index L of voltage stability is reasonably simplified, and the simplified index can avoid complex operation of voltage phasors, thus the calculation speed can be improved effectively. Based on the simplified index L an optimization model of available transfer capability （ATC） of AC/DC hybrid system, in which the constraint of voltage stability is taken into account, is proposed, and the proposed model is solved by primal-dual interior point method. By means of computing the index L, the impacts of different voltage stability margin on ATC and votlage stability of AC/DC hybrid system are researched. Case calculation results show that the simplification of index L is reasonable, and the proposed optimization model is effective.