ABB Ltd., Relarte Ltd.
India, SloveniaIn 1950 the first high voltage series capacitors were introduced by Swedish State Power Board (SE) and by Bonneville Power Administration (USA). Both installations were introduced on 220kV transmission systems. Today we can find series capacitors worldwide even at 765kV level. The main purpose of series compensation in power system is virtual reduction of line reactance in order to enhance the power system stability and increase loadability of transmission corridors. The principle is based on compensation of distributed line reactance by insertion of series capacitor (SC). The generated reactive power provided by the capacitor is proportional to the square of the current flowing through the compensated line and series capacitor. The response of SCs to system loading is this way automatic and instantaneous as long as the capacitor current remains within the specified operating limits. CIGRE Study Committee B5 (Protection and Automation) created working group WG B5.10 in 2002. The scope of work specified was: Review the presently available integrated techniques for protecting, controlling and monitoring high voltage lines with series capacitors (including thyristor controlled series capacitors) and the capacitor banks used in those lines and provide recommendations for their applications as well.
