HVDC Breaker: The Comeback of Gas-Discharge Tubes
To overcome the slow commercial uptake of hybrid HVDC circuit breakers, a long-range project is reconsidering gas-discharges tubes for use in HVDC circuit breakers. Stakes are high, since it may lead to a considerable decrease in cost, complexity and footprint of HVDC breakers and, moreover, with the opportunity to mount them in easy-to-install and maintain transportable containers…
Although the first DC circuit breaker concept was proposed in the 1970’s (using gas-discharge tubes at that time), it took around 40 years before the first economical, thus acceptable concept for a commercial use in a HVDC system[1] was developed: the ‘hybrid’ DC circuit breaker. Laboratory tested in 2013, it offered – at last – sufficiently low losses to be economic in a commercial HVDC system (see the 2014 paper) [5]. “However, the commercial uptake of such hybrid breakers has been slow, mainly because of their relatively large cost, complexity and footprint” explains Colin C. Davidson, from GE’s Grid Solutions Business. “New developments using optimized gas-discharge tubes could completely change this picture”.
[1] Grid operators increasingly use high Voltage Direct Current (HVDC) to carry high power over long distances, as direct current (DC) is superior to alternating current (AC) because it can transmit power without capacitive or inductive losses.