无人值班变电站与变电站自动化

无人值班变电站与变电站自动化(中文4800字,英文3600字)
自动重合闸的研制使无人值班变电站得以实现。在无人连续值班下的自动操作，首次于1914年在一个向电气化铁路供电的同步换流站中尝试。二十世纪二十年代初期，由于自动重合闸、保护继电器及电压自动控制设备的研制，使交流变电站有可能完全自动化。变电站须手动控制时，运行人员必须管理足够多数量的电力，才能使运行人员的工资较合理。这就决定了要采用大型变电站，一般通过许多馈电线向大的地区供电。向较远地区供电的馈线在带负荷前需要经过较长的输电距离。此外，随着大型变电站的负荷增长，变压器的容量也必须增加。这样就增加了二次侧的短路电流。有时，短路容量会超过已经安装断路器的开断容量。合适的补救措施包括母线分段、安装电抗器、或者这两部分的结合。这样的措施通常代价昂贵并不方便，且对运行的灵活性构成不必要的限制。

Unattended substation and substation automation
The development of automatic reclosing made the unattended substation practical .Automatic operation ,without the continuous presence of an attendant(operator),was first tried on the synchronous converter substations supplying an interurban electric railway in 1914.In the early 1920s,the development of automatic reclosing ,protective relays ,and means for automatic control of voltage made it possible for ac substations to be completely automatic .During the period when the substations had to be controlled manually ,it was necessary that they handle enough power to justify the operator`s wages .This dictated large stations ,frequently serving large areas by means of many feeders .The feeders that served the more distant parts of an area had to go a long way before they picked up any load .Furthermore ,as the load on a large substation grows ,transformer capacity has to be added .This increases the short-circuit current on the secondary side sometimes the short-circuit capacity exceeds the interrupting capacity of the circuit breakers already installed .Appropriate remedies include bus sectionalizing ,the installation of reactors or some combination of the two .Such measures are frequently expensive and inconvenient and they constitute an undesirable limitation on operating flexibility.