针对特高压直流接入受端电网的TCSC装置定容选址规划

Capacity and location planning of TCSC for UHVDC receiving end power grid

目前中国特高压直流接入的受端电网大多呈现“强直弱交”的情况。特高压受端换流站发生直流闭锁故障时,系统将发生大规模潮流转移,并可能引发部分线路过载。在此背景下,提出在受端电网中加入晶闸管控制串联电容器(TCSC)装置改善含特高压直流接入受端电网安全稳定问题,并建立了计及N-1安全约束的TCSC装置定容选址双层规划模型。上层规划模型以加装TCSC装置投资成本最小为目标,下层规划模型以N-1约束下最优潮流为目标,下层通过最优潮流求解结果选取给系统造成严重影响的N-1故障返回上层,增加新的约束,上下层通过互相迭代求得最终解。提出规划模型在修改IEEE 39节点系统中得到验证。

In China,most of the receiving systems with the UHVDC access are in the situation of"strong DC and weak AC"in present.After the DC blocking fault occurs,the system will undergo the large-scale power flow transfer,which may cause overloads in some lines.Under the circumstance,a thyristor-controlled series capacitor(TCSC)device is added to the receiving system,and a bilevel planning model is established for fixed-capacity and site selection of TCSC devices which takes N-1 security constraints into account.The upper-level planning model aims to minimize the investment cost of installing a TCSC device.The lower-level planning model aims to optimize the power flow under the constraint of N-1.Afterwards,the lower layer selects the N-1 fault that has a serious impact on the system operation through the optimal power flow solution.The lower layer results are returned to the upper layer to add a new constraint and the final solution is given by iterating.The planning model proposed in this paper are verified in the modified IEEE 39-node system.