摘要
蒲城发电厂1号发电机厂用系统的6kV开关于1997年更换为北京开关厂生产的新一代6kV真空断路器和真空接触器。真空断路器具有结构简单、维护方便、运行安全和适于频繁操作等优点，已在电力系统得到广泛应用。但由于早期生产的真空断路器在开断电动机时，容易产生高幅值的截流过电压，三相同期开断过电压和高频重复重燃过电压，对电动机绝缘造成损坏，所以真空断路器的操作过电压水平一直引起运行单位普遍关注。该操作过电压值与真空断路器触头电极材料的特性和触头形状尺寸、所切电动机容量参数、电缆截面尺寸和长度等有关。蒲城发电厂采用的北开生产的ZN12－10型真空断路器用于容量1000kW以上的电动机，其触头采用CuCr合金材料。真空灭弧室由国营宝光电工厂提供，并配用弹簧储能操作机构。容量为1000kW及以下的电动机采用真空接触器。本次试验针对蒲城发电厂实际回路进行真空断路器投切电动机过电压测量，以确定该型号真空断路器投切电动机的过电压水平及保护方式的合理性。
6kV breakers used in auxiliary power system of Nol unit,Pucheng Power Plant have been replaced by update 6kVvacuum breakers and vacuum contactors manufactured by Beijing Switchgear Factory. The vacuum breaker has many advantages, namely simple structure, convenient maintenance, safe operation and being suitable for frequent switching etc. These products have been widely used in power system. But when switching off motors, these early produced vacuum breakers were easy to generate high-amplitude cut-off overvoltage,three phase simultaneous switching off overvoltage and repeated high-frequent restriking overvoltage. These are harmful to motor's insulation, therefore the level of operating overvoltage of vacuum breakers is always a matter of interest to operation departments. The value of switching overvoltage is related to the property of electrode material, the shape of contacts in vacuum breaker, the capacity of operated motors, as well asthe section area and length of cable etc. Type ZNl2-10 vacuum breaker used in Pucheng Power Plant is applied to oPerate motors with capacity above 1000kW, its contact is made of CuCr alloy material. While motors with capacity less than 10000kW use vacuum contactor. In view of the actual circuits used in Pucheng Power Plant, the overvoltage in switching motors using vacuum breaker has been measured, so as to determine the overvoltage level in switching motors by using vacuum breaker of this type and the rationality of protection ways.
出处
《西北电力技术》
1999年第3期34-38,44,共6页
Northwest China Electric Power
关键词
真空断路器
电动机
过电压
操作
投切
vacuum breaker repeated high-frequent restriking overvoltage three phase simultaneous switching off overvoltage
