Patent ID: 11879948
Assignee: SANYO ELECTRIC CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  B  H | IPC G

Claim 0:
1. An electrical fault detection device that is mounted on a vehicle and includes:
an energy storage unit that is mounted on the vehicle in a state where the energy storage unit is insulated from a chassis ground of the vehicle and supplies electric power to a load in the vehicle;
a first switch that is inserted into a positive wire to which a positive electrode of the energy storage unit and one end of the load are connected; and
a second switch that is inserted into a negative wire to which a negative electrode of the energy storage unit and another end of the load are connected,
the electrical fault detection device comprising:
a coupling capacitor that has one end connected to a current path of the energy storage unit;
an alternating current (AC) output unit that applies a predetermined AC voltage to another end of the coupling capacitor via an impedance element;
a first voltage measurement unit that measures a voltage at a connecting point between the coupling capacitor and the impedance element;
a first determination unit that determines whether or not the electric power is leaked based on a voltage detected by the first voltage measurement unit;
a voltage dividing circuit that includes a first resistor, a second resistor, a third resistor, and a fourth resistor connected in series between the positive wire and the negative wire, the voltage dividing circuit having a connecting point between the second resistor and the third resistor and connected to the chassis ground; a fifth resistor that is further connected in series to the first resistor, the second resistor, the third resistor, and the fourth resistor connected in series; and a bypass switch connected in parallel with the fifth resistor;
a second voltage measurement unit that detects a potential at a connecting point between the first resistor and the second resistor and a potential at a connecting point between the third resistor and the fourth resistor, or a potential difference between the potentials; and
a second determination unit that determines whether or not the electric power is leaked based on the potential or the potential difference detected by the second voltage measurement unit,
wherein the voltage dividing circuit is connected between the positive wire between the first switch and the one end of the load and the negative wire between the second switch and the other end of the load.