Islanding protection system with active and reactive powerbalancing control for Tokyo Metropolitan power system and actualoperational experiences

摘要

The Metropolitan power system owned and operated by Tokyo ElectricnPower Company consists of several radial sub-power systems. Eachnsub-power system receives electric power from the 500 kV mesh bulk powernsystem, via 275 kV parallel overhead transmission lines and three 275 kVnunderground cables circuits which take the same route. These subpowernsystems cannot be interconnected to one another due to the restrictionsnimposed by short-circuit fault current. One of these metropolitan powernsystems supplies many politically and economically important loads andnthe load capacity of the locally installed power plant is small. Most ofnthe indigenous load is supplied from the bulk 500 kV power system vianthe parallel 275 kV tie transmission lines. This metropolitan systemnconsists entirely of 275 kV, 154 kV and 66 kV underground cables. If thenpower supply from the bulk 500 kV power system is interrupted by a faultnon the tie transmission line, the metropolitan power system will benseparated as a heavily overload system with large shunt capacitance. Thenauthors have therefore installed an islanding protection system withnactive and reactive power balance control functionality to protect thenmost important loads in the metropolitan area from serious black out