Patent ID: 9209616
Filing Date: 2015-12-08
Classification: H02H

Abstract:
1. A power supply circuit for an on board energy source or storage device, and particularly for a super-capacitor storage unit having a plurality of super-capacitors interconnected to one another and a first and a second terminal, the power supply circuit comprising: a positive bus connecting the first terminal of the super-capacitor storage unit to a positive pole of a DC high voltage feeding source; a negative bus connecting the second terminal of the super-capacitor storage unit to a negative pole of the DC high voltage feeding source, the negative bus being connected to ground at a grounding point downstream of the DC high voltage feeding source; and a disconnecting device configured to disconnect the super-capacitor storage unit from the DC high voltage feeding source in response to detection of fault current circulation due to insulation losses to the ground of the super-capacitor storage unit, wherein the disconnecting device comprises a high speed circuit breaker and a differential relay which are connected in series only along the negative bus, and wherein, between the second terminal and the grounding point, the differential relay is further connected in series in the positive bus and is configured to generate an activation signal of the high speed circuit breaker in response to the fault current circulation detected by measuring differences in currents in the positive and in the negative bus.