Abstract
A new concept of series LC DC Circuit Breaker is presented and experimental results on 1200 V, 200 A hardware demonstrator are shown in this article. This mechanical DC CB topology converts DC fault current into AC current by inserting a series capacitor. The AC current can be interrupted by a conventional AC CB at one of the zero crossings and will not be increasing because of series capacitor. Only mechanical switches are used including the commutation switch. The commutation switch has design with lateral contact overlap which facilitates current commutation without arcing.
The experimental 1200V, 200A scaled demonstrator LC DC CB which commutates DC current in 0.4 ms is described. A fast air disconnector is used as the commutating switch. This disconnector has 3mm contact distance and 2 ms total opening time in the scaled laboratory hardware. The experimental tests confirm that arc-less current commutation into a parallel capacitor using a mechanical switch is possible. The main advantage of the proposed topology is the high operating speed. The results show that it is possible to apply increasing voltage stress across disconnector contacts while contacts are moving apart without causing dielectric breakdown.
The initial design parameters are presented for a 320kV DC CB based on the same concept. The initial conclusion is that expected performance and size of components are encouraging.
The experimental 1200V, 200A scaled demonstrator LC DC CB which commutates DC current in 0.4 ms is described. A fast air disconnector is used as the commutating switch. This disconnector has 3mm contact distance and 2 ms total opening time in the scaled laboratory hardware. The experimental tests confirm that arc-less current commutation into a parallel capacitor using a mechanical switch is possible. The main advantage of the proposed topology is the high operating speed. The results show that it is possible to apply increasing voltage stress across disconnector contacts while contacts are moving apart without causing dielectric breakdown.
The initial design parameters are presented for a 320kV DC CB based on the same concept. The initial conclusion is that expected performance and size of components are encouraging.
Original language | English |
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Publication status | Published - 7 Jun 2019 |
Event | CIGRE Symposium 2019 - Aalborg, Denmark Duration: 4 Jun 2019 → 7 Jun 2019 |
Conference
Conference | CIGRE Symposium 2019 |
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Country/Territory | Denmark |
City | Aalborg |
Period | 4/06/19 → 7/06/19 |
Bibliographical note
This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 691714.The author is grateful to Mr R. Osborne from University of Aberdeen for help with testing LC DC CB.
Keywords
- DC Circuit Breakers
- DC Transmission Grids
- HVDC