To precisely determine the presence or absence of any failure on a voltage detection circuit while inhibiting that device configuration is complicated.
When it is determined that a cell voltage of any capacitor cell exceeds a prescribed regenerative limit voltage VR, a control unit 17 anticipates the total voltage (release determination voltage SVL) when the cell voltage of the capacitor cell reaches a prescribed determination voltage VT below the regenerative limit voltage VR, based on a detected total voltage detection value SVE. When it is detected that the detection value SVE is below the voltage SVL in the state that it is continued that a cell voltage of any capacitor cell exceeds a prescribed voltage VR, a control unit 17 determines that the detection value of the cell voltage of the capacitor cell is abnormal, and determines that failure is generated in a cell voltage detection circuit of a protective device 16.
YAMAMOTO KOICHI
Tadashi Takahashi
Masakazu Aoyama
Suzuki Mitsuyoshi
Kazuya Nishi
Yasuhiko Murayama
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