变压器混合式有载分接开关熄弧方法的仿真及试验研究

Study on Simulation and Experiments of Method of Extinction Hybrid On-Load Tap Changer in Transformers

变压器传统有载分接开关切换过程中的电弧会显著降低触头寿命和加速变压器油劣化。为了解决该问题,提出了一种新的混合式有载分接开关方法,并试制了实验室的模型样机。这种方法采用伸缩动触头保证切换时序,以机械组件的运动实现晶闸管模块的无源触发,以晶闸管辅助机械开关实现切换过程中的熄弧。搭建了熄弧电路的仿真模型进行仿真,并建立了标准的低压切换试验回路进行试验。仿真结果表明:晶闸管门极触发回路简单可靠,能有效抑制电弧电压的建立,从而消除电弧。试验结果表明:晶闸管在一个切换过程中会被触发4次,其中2次电流自然过零关断,2次被机械开关旁路后关断。仿真与试验结果相互验证,充分说明了提出的混合式有载分接开关无弧切换方法的可行性。

Arc appears in the switching process of traditional on-load tap changer of transformer significantly, reducescontact life, and accelerates the deterioration of transformer oil. To solve this problem, we developed.a procedure of hy-brid on-load tap changer, and made a laboratory prototype following the procedure. In the procedure, telescopicmovement moving contacts were adopted to ensure switching timing, mechanical components were used for passivelytriggering of thyristor modules, and the thyristors were used to assist machinery to extinguish arcs. Moreover, we estab-lished a numerical model of the arc-eliminating circuit to conduct simulations, and set up a standard low-voltageswitching test circuit to conduct experiments. The simulations show that the thyristor gate trigger circuit is simple and re-liable, and it is effective in inhibiting the establishment of arc voltage and hence eliminating arcs. The experimentalresults show that, in one switching process of a thyristor, the thyristor will be triggered by four times： two are natural cur-rent zero-crossing off, the other two are offafter bypassed by mechanical switch. The simulation and experimental resultsvalidate each other, which further proves the proposed hybrid arc-free load tap switching method to be feasible.