Hitachi Automotive Systems, Ltd.

Issei Toda

Koichi A Ono

Satoru Shigeta

Shinichirou Hida

An internal electric circuit device that is connected to a connector terminal at the time of being short-circuited can be protected, but a load connected to the connector terminal has not been able to be protected. When a voltage of a cathode of a diode becomes a voltage equal to or more that an output voltage of a power source circuit by a short circuit of a positive terminal, an output voltage of an amplifier changes from the output voltage of the power source circuit to a voltage of a point connected to a negative power terminal of the OP amplifier. When the output voltage of the amplifier becomes 0 V, a voltage difference between the gate and the source of a switching element becomes equal to or more than a predetermined voltage. Therefore, the drain and the source of the switching element enter an open state, and the current flowing a negative terminal is blocked. Therefore, it is possible to protect a load from overcurrent.

Electric circuit device

Even in the case in which an overvoltage is generated when a vehicle is in a non-operation state, the overvoltage can be suppressed. A power conversion device is connected to a three-phase motor mounted on a vehicle and includes an inverter circuit, a gate drive substrate, and a motor control substrate. In the motor control substrate, when the vehicle is in the non-operation state and a regenerative voltage applied from the three-phase motor to the inverter circuit becomes equal to or more than a predetermined threshold value, a power supply circuit supplies operation power to a control circuit. The control circuit starts when the operation power is supplied from the power supply circuit and outputs gate control signals to a driver circuit of the gate drive substrate, such that regenerative energy according to the regenerative voltage is consumed between the three-phase motor and the inverter circuit.

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Hitachinaka, Japan

Issei Toda