scope:

This part of IEC 60143 covers protective equipment for series capacitor banks, with a size larger than 10 Mvar per phase. Protective equipment is defined as the main circuit apparatus and ancillary equipment, which are part of a series capacitor installation, but which are external to the capacitor part itself. The recommendations for the capacitor part are given in IEC 60143-1:2004. The protective equipment is mentioned in Clause 3 and 10.6 of IEC 60143-1:2004.

The protective equipment, treated in this standard, comprises the following items listed below:

- overvoltage protector,

- protective spark gap,

- varistor,

- bypass switch,

- disconnectors and earthing switches,

- discharge current-limiting and damping equipment, 

- voltage transformer,

- current sensors,

- coupling capacitor,

- signal column,

- fibre optical platform links,

- relay protection, control equipment and platform-to-ground communication equipment. See Figure 1.

Principles involved in the application and operation of series capacitors are given in Clause 5.

Examples of fault scenarios are given in Clause 5.

Examples of protective schemes utilizing different overvoltage protectors are given in 4.1.