Recently

the 500 kV electric power transmission lines and substations have been constructed and operated in the four large electric systems of our country successively. The original plan of reactive power compensating equipment was to adopt synchronous condenser. After analysis and comparison

we decided to select the combination of shunt capacitors and shunt reactors. The capacity of shunt reactors is half as many as that of the shunt capacitors. In some substations in Wuhan and Shenyang the SVCs introduced from abroad have been used

All of these equipments are connected to the third winding of main transformers. The total capacities of capacitor banks reach 120-240 Mvar. These large capacitor banks are also unprecedented in our country

therefore designers met many problems

such as

the analysis and discussion about selection between synchronous condenser and shunt capacitor

parameters of the capacitor

the scheme of connection and protection

arrangement and installation

the selection of accessories

etc. This paper will discuss the main problems on design technique and offer the suggestion for development of ultrahigh voltage shunt capacitor instllations.