A fundamental change to the classic HVDC system technology.
ABB introduced the concept of Capacitor Commutated Converters (CCC) to the market in 1995. This was, in fact, the first fundamental change to have been made to the classic HVDC system technology since 1954! The first CCC-station, the Garabi 2 200 MW station in Brazil, is operating since June 1999!
CCC offers the following advantages:
- Improved dynamic performance
- Significantly better stability, in particular when connected to AC networks with low short circuit capacity and in transmissions with long DC cables
- Dependable performance in the event of AC system disturbances, with reduced risk of commutation failures
- Lower load rejection overvoltages
- No need to switch AC filters or shunt capacitor banks to compensate for converter reactive power consumption
CCC has proven particularly suitable in back-to-back projects where the converter station lies in the periphery of the AC networks or is connected via long lines to strong substations. Both these situations can result in a low short circuit ratio at the converter station.