To detect a failure of an electric leak detection circuit for detecting a drop in a resistance value of an insulation resistance between a ground line of a direct current power source installed on a vehicle and a vehicle body earth, with the electric leak detection circuit itself.SOLUTION: When a third corresponding relationship between a wave height value VppL1 of a voltage V1 output from an insulation resistance measurement circuit 3 when a first failure detection oscillation signal S1 is output from an oscillation circuit 2 and a wave height value VppL2 of a voltage V2 output from a floating capacitance measurement circuit 4 when the first failure detection oscillation signal S1 is output from the oscillation circuit 2 is not included in a fluctuation trend of first to second corresponding relationships calculated when an electric leak detection circuit 1 has no failure, it is detected that the insulation resistance measurement circuit 3 or the floating capacitance measurement circuit 4 has a failure.SELECTED DRAWING: Figure 1
【課題】車両に搭載される直流電源のグランドラインと車両のボディアースとの間の絶縁抵抗の抵抗値の低下を検知する漏電検知回路の故障を漏電検知回路自身で検知する。【解決手段】発振回路2から第1の故障検知用発振信号S1が出力されているときに絶縁抵抗測定回路3から出力される電圧V1の波高値VppL1と、発振回路2から第1の故障検知用発振信号S1が出力されているときに浮遊容量測定回路4から出力される電圧V2の波高値VppL2との第3の対応関係が、漏電検知回路1が故障していないときに算出される第1の対応関係から第2の対応関係までの対応関係の変動傾向に含まれていない場合、絶縁抵抗測定回路3または浮遊容量測定回路4が故障していることを検知する。【選択図】図1
ELECTRIC LEAK DETECTION CIRCUIT AND FAILURE DETECTION METHOD
漏電検知回路及び故障検知方法
2020-07-09
Patent
Electronic Resource
Japanese
LEAK DETECTOR, AND LEAK DETECTION METHOD FOR ELECTRIC VEHICLE
European Patent Office | 2019
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