计及动态稳定约束的交直流系统区域间可用输电能力计算

Calculation of Available Transfer Capability of Hybrid AC/DC Power System Considering Dynamic Security Constraint

以常规静态安全约束的可用输电能力计算模型为基础,构建计及系统动态稳定约束的交直流系统可用输电能力模型。采用计及网络影响的动态等值新方法对各区域内发电机组进行等值,有效提高了系统的等值精度。根据等值后交直流系统的特点,设计了可有效计及电力系统非状态变量影响的非线性直流调制控制策略。该策略在有效改善系统动态特性的同时显著提高了系统的区域间可用输电能力。算例结果验证了所建模型的合理性和所采用方法的有效性。

Based on available transfer capacity （ATC） model considering conventional static state security constraint, an ATC model for hybrid AC/DC power system, in which dynamic stability constraint was taken into account, was built. Using a new method for dynamic equivalence, in which the influences of network were considered, the accuracy of equivalence was effectively improved. According to features of post-equivalence hybrid AC/DC power system, an optimal supplementary control strategy for nonlinear DC modulation, in which the influences of non-state variables in power system were effectively taken into account, was designed. The designed strategy could improve dynamic characteristics of the AC/DC power system, meanwhile the interregional ATC of hybrid AC/DC power system could be improved. The rationality of the built model and the effectiveness of the adopted method were verified by simulation results of modified IEEE 30-bus system.