Fault detector for detecting faults in a DC capacitor circuit
First Claim
1. A fault detector for detecting faults in a DC capacitor circuit comprising a plurality of parallel-connected capacitor circuits each having a group of series-connected DC capacitors for suppressing voltage pulsation and incorporated into the DC unit of an inverter for converting direct current into alternating current, each of said groups of series-connected capacitors having a junction between the capacitors of the group, which comprises:
- a comparison means connected to a junctions of the series-connected DC capacitors of said plurality of the parrallel-connected capacitor circuits, to compare potentials at the respective junctions of the respective series-connected DC capacitors of the parallel-connected capacitor circuits to detect a difference between said potentials, said comparison means including means for detecting said difference in potential and the magnitude of said difference.
1 Assignment
0 Petitions
Accused Products
Abstract
A fault detector for detecting faults in a DC capacitor circuit connected to the DC buses of an inverter circuit using semiconductor device for converting direct current into alternating current to suppress the voltage pulsation and comprising a plurality of parallel-connected capacitor circuits each having a plurality of series-connected DC capacitors. The fault detector comprises a comparison means connected to the junctions of the series-connected DC capacitors to compare the respective potentials of the parallel-connected capacitor circuits, and detects the short-circuit and time-aging of the DC capacitors of the parallel-connected capacitor circuits rapidly on the basis of the output signal of the comparison means.
-
Citations
15 Claims
-
1. A fault detector for detecting faults in a DC capacitor circuit comprising a plurality of parallel-connected capacitor circuits each having a group of series-connected DC capacitors for suppressing voltage pulsation and incorporated into the DC unit of an inverter for converting direct current into alternating current, each of said groups of series-connected capacitors having a junction between the capacitors of the group, which comprises:
a comparison means connected to a junctions of the series-connected DC capacitors of said plurality of the parrallel-connected capacitor circuits, to compare potentials at the respective junctions of the respective series-connected DC capacitors of the parallel-connected capacitor circuits to detect a difference between said potentials, said comparison means including means for detecting said difference in potential and the magnitude of said difference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
10. A fault detector for detecting faults in a DC capacitor circuits, which comprises:
-
a parallel-connected circuit comprising a plurality of series capacitor circuits each comprising a plurality of DC capacitors for suppressing voltage pulsation, and a plurality of series voltage dividing resistor circuits each comprising a plurality of voltage dividing resistors for leveling the potential differences across the individual DC capacitors, each of said series capacitor circuits including a junction between the capacitors comprising said series capacitor circuits and each of said series voltage dividing resistor circuits including a junction between said resistors comprising said voltage dividing resistor circuits; and comparison means connected to the parallel-connected circuit so as to determine a difference in potential between potentials of two lines connected to the respective junctions of the DC capacitors of the series capacitor circuits and the respective junctions of the voltage dividing resistors of the series voltage dividing resistor circuits of the same two groups of the series capacitor circuits and the series voltage dividing resistor circuits, respectively. - View Dependent Claims (11, 12, 13, 14, 15)
-
Specification