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1. (WO2011157306) BREAKER FAILURE PROTECTION OF HVDC CIRCUIT BREAKERS

Pub. No.:    WO/2011/157306    International Application No.:    PCT/EP2010/063377
Publication Date: Dec 22, 2011 International Filing Date: Sep 13, 2010
IPC: H02H 7/26
H02H 3/44
H02H 7/30
Applicants: ABB RESEARCH LTD
BERGGREN, Bertil
WANG, Jianping
PAN, Juiping
LINDEN, Kerstin
NUQUI, Reynaldo
Inventors: BERGGREN, Bertil
WANG, Jianping
PAN, Juiping
LINDEN, Kerstin
NUQUI, Reynaldo
Title: BREAKER FAILURE PROTECTION OF HVDC CIRCUIT BREAKERS
Abstract:
A breaker failure protection system (100) for a high voltage direct current, HVDC, circuit breaker (103) is provided. The circuit breaker is arranged for interrupting a DC circuit (101, 102) upon reception of a trip signal (108). The protection system comprises a current sensor (104), at least one inductor (105, 106), and a breaker failure detection unit (107). The current sensor is arranged for measuring a current I(t) through the DC circuit. The at least one inductor is connected in series with the DC circuit. The breaker failure detection unit is arranged for assessing, whether the circuit breaker has failed, and sending, if the circuit breaker has failed, a trip signal (109) to an adjacent circuit breaker. The assessment is based on the measured current. The stability of HVDC grids may be improved by sending, in case of a breaker failure, a trip signal to adjacent circuit breakers. Further, a method of breaker failure protection for an HVDC circuit breaker is provided.