某核电站启动锅炉的电气设计和调试中问题的解决

Resolution of Problems Involved in the Electrical System Design and Commissioning Tests of Pre-operational Test Boilers for a Nuclear Power Plant

根据某核电站在技术条件、安全性和可靠性对启动锅炉的电气设计的特殊要求,以及启动锅炉的负荷性质和容量大小,提出启动锅炉的电气设计的方案。该电气设计采用三相五线制交流380 V双电源进线,每路进线电源带一段母线,两段母线间设母联开关;针对成组电动机的自起动进行校验;调试过程中出现进线断路器不定时跳闸,从原理上分析产生问题的原因,并针对调试中出现的问题,提出了在三相五线制电气系统中解决零线共用形成环流问题的方法。

In accordance with the special requirements for the design of the electrical system of pre-operational test boilers for a nuclear power plant,proposed was a design scheme for the pertinent electrical system.The special requirements include the relevant technical conditions,safety and reliability of the boiler electrical system as well as the loading nature and capacity of the pre-operational test boilers.The design of the electrical system adopts a three-phase five-wire system of AC 380 V dual power source lead-in wires with each lead-in wire power source incorporating a section of busbar and a bus coupler being provided between any two sections of the busbar.Moreover,the motors in groups would undergo a check inspection through a self start-up.During the commissioning test,occasional trips occurred to the lead-in wire circuit-breakers.The causes of such problems were analyzed from the perspective of underlying principles.As regards the problems emerging in the commissioning test,proposed was a method to solve the problem through the formation of a ring current by the use of a common zero line in the three-phase five-wire electrical system.