配电变压器无触点有载调压中反并联晶闸管光纤触发方案

Optical Trigger Scheme of Inverse-parallel Thyristor in Contactless On-load Tap-changing Voltage for Distribution Transformer

配电变压器无触点有载调压中作为分接开关的反并联晶闸管位于10kV侧,而晶闸管触发电路以及控制系统位于0.4kV侧。针对有载调压装置横跨变压器一、二次侧所面临的绝缘问题,通过对光纤通信技术和高压取能电路的研究,结合自取能式晶闸管触发电路及其在耐压方面的改进,设计了基于光纤隔离的触发方案。通过对硬件电路进行参数设计和实验,验证了触发方案局部和整体电路原理的可行性。实验结果表明该方案能够解决高压反并联晶闸管触发的绝缘问题。

As the tap-changer of contactless on-load tap-changing voltage for distribution transformer inverse-parallel thyristor is located in 10 kV side of the transformer, while thyristor trigger circuit and control system are in 0.4 kV side. In face of the insulation problem of on-load tap-changing voltage device across the primary and secondary side of transformer, a trigger scheme based on optical fiber insulation is designed, which is via studies on fiber optical communication technology and high voltage side dc conversion circuit, combined with automatically zero-cross operating trigger circuit and its improvement on high voltage withstanding. The feasibility of the principle of optical trigger scheme is verified through parameters design and experiment of hardware circuit. The experimental results show that the scheme can solve the insulation problems of inverse- parallel thyristor trigger in high voltage side of distribution transformer.