SCiBreak’s DCCB module tested at KEMA

During last week, SCiBreak AB tested a DC circuit breaker module prototype at the KEMA laboratories of DNV GL, as a task within work package 10. A fault current of 10.8 kA was delivered by short circuit generators and was interrupted against a transient voltage exceeding 40 kV.

These tests verify the function of the developed technology and constitute a major milestone for SCiBreak. The fault current was interrupted, and the corresponding energy of 0.6 MJ was dissipated in surge arresters included in the module. An artificial zero-crossing was created in the vacuum interrupter by an oscillating current excited by a power electronic converter. An ultra-fast Thomson coil actuator created the necessary contact separation in less than 3.5 milliseconds after the trip order was received by the DCCB module.

The photo below shows the tested module surrounded by engineers from KEMA Laboratories and SCiBreak.

Concept proved for 10 kA and 40 kV

SCiBreak got some good news for Christmas, a significant milestone was reached. For the first time, a 10 kA current was interrupted against a recovery voltage of 40 kV with SCiBreak’s technology. After ramping up the ratings of the prototype during the whole year of 2017, we thus reached our initial target.

The current was successfully commutated to the energy absorption branch within 3 ms after the trip order was given to the circuit breaker. This was achieved thanks to the ultra-fast main interrupter which is operated with our Thomson-coil actuator.

In the picture below, the measured resonant current reaches the same value as the fault line current at 800 us. At that moment, the arc is extinguished and the voltage across the breaker increases to a voltage level of nearly 40 kV.

These current and voltage levels correspond to the test that will be performed at the KEMA laboratory next june. To be continued!