Basic design / specifications of GIS for UHV AC and its verification test at site

摘要

In Japan, to satisfy the steady increasing demand for electricity in urban areas, it is planned toconstruct 1100kV power network system. 1100kV substation equipment have been developedand a part of 1100kV transmission lines were constructed.Because 1100kV substation would be located in the mountain areas, it is necessary that FullGas Insulated Switchgear (Full-GIS) is applied to make substation area compact as possibleso as to meet installation-space constrains, to harmonize with natural environment and tominimize cost.To reduce construction cost, rationalization of insulation specification is required. Substationequipment, such as high performance surge arrester and resistor fitted disconnector , whichsuppress various overvoltage, were developed and the insulation specifications were reduced.As a result, Lightning Impulse Withstand Voltage (LIWV) of GIS is determined as 2250kVand that of transformer is determined as 1950kV. By adopting gas circuit breaker withmaking/breaking resistor, the insulation specifications of all power network equipmentincluding transmission lines are coordinated. To determine the specifications and performanceof 1100kV facilities, not only compactness and rationalization, but also reliability are required.Therefore, manufacturers reviewed design in detail by applying analysis technology andmaking prototype equipment. ‘UHV Equipment Test Station' was constructed based on thesespecifications, field verification test has been carried out since 1996.In field verification test, performance tests and voltage/current applied test were carried out,and required performance and long-term reliability were confirmed.By carrying out these tests, the maturity and reliability of Japanese1100kV facilities areconfirmed.