Enabling Magnetics for DC Circuit Breaker

Eaton, alongside its partners, is developing an ultra-high efficiency medium-voltage, direct-current mechanical/solid-state hybrid circuit breaker. This breaker will employ an ultra-low on-state resistance vacuum contactor, a power-electronic current interruption circuit, a Transient Commutation Current Injection circuit, and a controllable inductor to limit the fault current. All components are designed and matched to reduce on-state losses to 99.97%. At the conclusion of the 36-month project, the technology will be validated on a TRL-5 circuit breaker prototype.

Sponsor

Principle Investigators

Subhashish Bhattacharya

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Circuit protection is a key enabler for future medium-voltage direct-current distribution systems. Eaton with its partners will develop, build and test an ultra-high efficiency medium-voltage, direct-current mechanical/solid-state hybrid circuit breaker (HCB) using a custom designed and matched high-speed actuator/vacuum switch (HSVS) connected in parallel with a power-electronic current interruption (PCI) circuit and an innovative Transient Commutation Current Injection (TCCI) circuit. During the fault response process, a controllable inductor will be employed to limit the rate of rise of fault current, allowing the size and peak rating of the TCCI and PCI to be minimized and aid the PCI circuit in quickly driving the current to zero.
Due to the vacuum contactor’s ultra-low on-state resistance and the lack of any series connected commutation circuit, the proposed topology is expected to have minimal on-state losses, exceeding 99.97% efficiency. The program is divided into seven main technical efforts including development of each of the principle HSVS, PCI, TCCI, and controllable inductor elements, as well as development of the HCB Architecture, Control Electronics, and Final Integration and Testing. At the end of the 36-month program the technology will be validated on a TRL-5 circuit breaker prototype.