机械式有载分接开关改进方案的设计与研究

Design and Research on the Improvement Scheme of Purely Mechanical On-load Tap-changers

机械式有载分接开关因其机械结构所致,工作中存在燃弧、过渡损耗等问题,需要定期对其进行维护与检修,耗费大量资源,一直被广大工程技术研究人员所关注。从工程实际出发,以国内某机械真空滑动复合式有载分接开关为对象,为了抑制电弧、降低工作损耗的目的,进行了理论研究和实践分析。拟定了初步改进方案、分析了改进机理,在不改变原有机械拓扑结构的前提下,采用增加辅助的电力电子开关的方法,实现设备切换过程的优化,消除了过渡损耗,降低了触头的工作压力。利用基于模型设计的思想,设计并实现了对切换开关的时序控制,完成了实验室小功率样机的搭建。通过建模仿真和实测分析,改进后切换燃弧时间可降低至100μs左右,实现了对切换电弧功率的有效抑制。该研究以期为下一步进行全功率试验奠定理论和实践基础。

A purely mechanical on-load tap-changer has the problem of arcing and transition wearing in the operation process because of its mechanical structure, thus should be maintained and overhauled regularly, which costs a lot of resources and has been concerned by a large number of engineering technical researchers. Consequently,on the basis of the engineering practice, taking a mechanical type of vacuum sliding integrated topology OLTC in China as an example,we theoretically researched and practically analyzed the aspects of arc restriction and reduction of working loss. Moreover,we analyzed the preliminary improvement scheme and the improvement mechanism;under the condition of not changing the original mechanical topology, we realized the optimization operation of equipment by adding auxiliary power electronic switch, and realized the elimination of the transition wear and decrease of the working pressure of the contact.Furtermore,a small power prototype was designed and built in the laboratory by the method of model-based design to realize the sequence control of diverter. Through modeling simulation and experimental analysis, the improved diverting arc burning time could be reduced to about 100μs,thus the diverting arc power could be effectively suppressed. This study can lay a theoretical and practical foundation for the full power tests in the future.