用于提高输电能力的TCSC选址和定容方案

支路传输功率、节点电压等的越限是制约系统输电能力提高的重要因素，为此文章采用连续潮流模型，在临界运行点推导了输电能力对支路电抗灵敏度的数学表达式，提出根据此灵敏度排序结果确定可控串联补偿器(thyristor controlled series capacitor，TCSC)安装地点的新方法。该方法中，TCSC安装位置确定以后，将安装TCSC之前发生越界的不等式约束在其边界值处用等式形式表示出来，并设定为已知条件，将TCSC对其所要安装支路的补偿度设定为一个新的未知量，扩展常规潮流方程，以求取扩展潮流不匹配函数的最小值为目标，计算支路的最优补偿度。对IEEE30节点和IEEE118节点系统的仿真计算结果表明该文所提出的选址和定容方法是有效的。

Selection Scheme for Installation Site and Optimal Capacity of TCSC to Increase Transfer Capability

The influence of constraints such as voltage limits, branch power limits and limits of other electric equipments are critical for transfer capability. By use of continuation power flow model, a mathematical expression for the first order sensitivity of the transfer capability with respect to branch reactance is deduced at the critical operating point, and according to the results of sensitivity ordering a new method to determine the installation site of thyristor controlled series capacitor (TCSC) is proposed. After the installation site is ascertained, the inequality constraints which are out of bound before the installation of TCSC are represented by equalities and set as known conditions; the compensation degree of TCSC with regard to the branch where it is to be installed is set as a new unknown quantity; then conventional power flow equations are expanded and taking the minimum of expanded power flow mismatching function as object the optimal compensation degree is calculated. Simulation results of IEEE 30-bus system and IEEE 118-bus system show that the proposed method to select the installation site and optimal capacity of TCSC is effective.