均压方式对双断口真空断路器短燃弧开断特性的影响OA

In this paper,an experimental system for short-circuit current interruption of double-break vacuum cir-cuit breakers is set up.Seven groups of controlled variable comparison tests are set up to systematically investigate the influence of capacitive grading and RC grading on minimum arcing time,critical arc-extinguishing gap,voltage distribution and transient characteristics across the breaker,and the transient process of asynchronous breakdown.The test results show that,compared to the case without grading mode,both capacitive and RC grading modes can ef-fectively shorten the minimum arcing time,reduce critical arc-extinguishing gap and enhance minimum arcing inter-ruption capability.In case of capacitive grading,increasing grading capacitance can improve voltage uniformity across open contacts,but the perfroamnce enhancement shows saturation trend.While,in case of RC grading,the in-terruption performance first increases and then decreases with the series resistance,reaching the optimum perfor-mance at resiatance of 40 kΩ.The transient process analysis of asynchronous breakdown indicates that R-Cgranding enables the breakdown contacts to rapidly rrecover its voltage-withstanding capability and improves the voltage dis-tribution across open contacts,whereas neither capacitve grading nor the condition without grading exhibits such characteristics.The interruption performance of pure capacitive voltage grading is governed by the uniformity of volt-age distribution,while that of RC voltage grading is determined the uniformity of voltge grading and the rapid voltage recovery following asynchronuous breakdown.The conclusion in this paper can provide theoretical support and engi-neering reference for grading scheme selection and parameter optimization of double-break vacuum circuit breakers.