近年来发生了数起换流变压器有载分接开关在档位调节过程中爆炸起火的严重事故.针对此问题,提出了一种新型分体式换流变有载分接开关的设计方案,将切换开关部分与变压器本体分离,有效避免分接开关故障影响的扩大.切换开关各触头由真空永磁开关替代且操作机构独立配置,结合内部支路配置的电流采样装置,实现切换过程的监测可控.提出了分体式同步控制逻辑和切换开关分步控制逻辑,实现了分接开关调档过程的状态监测及故障保护.样机的试验结果验证了分体式换流变压器有载分接开关方案的可行性和有效性.
In recent years,there have been several serious incidents involving explosions and fires in on-load tap changers(OLTCs)of converter transformers during the adjustment.To address this issue,a novel design solution for a split type OLTC is proposed,separating the switching part from the transformer body to effectively prevent the faults in the tap changer being intensified.The vacuum permanent magnet switch replaces each contact of the switch,and the operating mechanism is independently configured.Based on current sampling devices arranged in the internal circuit,monitoring and control of the switching process are achieved.Split type synchronous control logic and step control logic for the diverter switch are introduced to monitor the status and provide fault protection during the tap changer adjustment process.Experimental results from the prototype validate the feasibility and effec-tiveness of the proposed OLTC design for converter transformers.