A ground fault detection device connected to a high-voltage battery and a positive electrode side Y capacitor includes a detection capacitor operating as a flying capacitor and a discharge circuit including at least a fifth switch. A one end of the discharge circuit is connected to a first circuit that connects a positive electrode side of the high-voltage battery and a one end of the detection capacitor. An another end of the discharge circuit is connected to a second circuit that connects an another end of the detection capacitor and a ground.

A battery pack enclosure, a battery module, and a method are provided to detect damage to in a crash event. The battery pack enclosure may include a plurality of battery modules, wherein each battery modules includes a plurality of adjacent battery cells. The battery pack enclosure may also include a sensor and an electronic control unit electronically connected to the sensor, the electronic control unit configured to monitor the sensor to detect damage to the battery pack enclosure. The sensor may comprise a mesh of resistive wires, and the electronic control unit monitors the overall resistance of the mesh resistive wires. The overall resistance of the mesh resistive wires can be used to determine whether there is damage to the battery pack enclosure. If damage is detected, the damage can further be located, and an alert sent.

A ground fault detection device includes: a detection capacitor; a switch group for switching between a first charging path connecting the battery and the detection capacitor, a second charging path connecting the battery, a negative side insulation resistance and the detection capacitor, a third charging path connecting the battery, a positive side insulation resistance and the detection capacitor, and a measurement path for measuring a charging voltage of the detection capacitor; and a controller configured to calculate the insulation resistance based on a charging voltage measured value of the detection capacitor which exists after charging each of the charging paths, wherein after measurement of the charging voltage of the second charging path, the controller is configured to cause the switch group to switch to the third charging path before switching to the first charging path.

A rotating machine power conversion device is obtained which achieves operational continuation in a rotational speed range in which the operational continuation is enabled, even when a single phase of an electrical power conversion device made of switching devices causes a disconnection or turn-off failure. The rotating machine power conversion device comprises: a normality-case/abnormality-case current control device selection device for transferring between a normality-case current control device and an abnormality-case current control device in accordance with a determination result of an abnormality determination device; and an abnormality-case current control device/power conversion halt device selection device, using a rotational speed calculation device, for transferring between the abnormality-case current control device used when a rotational speed is lower than that being prespecified, and the power conversion halt device used when a rotational speed is higher than that being prespecified.

In a method for operating an electric vehicle and an electric vehicle, including an electric traction drive device for driving vehicle, a control device for controlling the driving, a first energy storage device, for supplying the control device using a first DC voltage, a second energy storage device, for supplying the traction drive device using a second DC voltage, and an energy supply unit for providing an output DC voltage, the first energy storage device is connected to the second energy storage device via a converter device, the first energy storage device is connected to the energy supply unit, the converter device converts the first DC voltage into the second DC voltage, and a power flow from the second energy storage device to the first energy storage device is prevented.

A cart may include: a driving wheel; a motor configured to rotate the driving wheel; a motor drive circuit configured to control electric power supply to the motor; a motor control device configured to control the motor via the motor drive circuit; a switching element arranged on an electric power supply path to the motor drive circuit; a switch circuit arranged separately from the motor control device and configured to switch the switching element between a conduction state and a non-conduction state; and an operation member arranged on the cart and configured to be operated by a user. The cart may operate in a manual mode in which the motor is driven when the operation member is on and the motor is stopped when the operation member is off, and in an automatic mode in which the motor is driven regardless of whether the operation member is on or off.

A dual power supply apparatus includes a main power grid that supplies power by a first battery to an autonomous vehicle and a redundant power grid that supplies power to a dual power load based on a second battery, in an emergency driving mode due to a failure in the main power grid.

A low voltage DC-DC converter of an environmentally friendly vehicle includes a first DC-DC converter configured to drop a second voltage lower than a first voltage supplied to a drive motor of the environmentally friendly vehicle to a third voltage, a voltage regulator configured to regulate the third voltage to output a fourth voltage lower than the third voltage, a controller configured to operate in response to the fourth voltage, and a second DC-DC converter configured to convert and output the first voltage into the third voltage in response to an output signal of the controller, in which an output voltage of the second DC-DC converter is supplied to the voltage regulator.

When a voltage measurement value of a first voltage sensor that measures voltage at a direct current end of an inverter exceeds an overvoltage threshold value, and a battery is non-chargeable, a controller of a fuel cell electric vehicle is configured to drive an electric power consumption device until the voltage measurement value falls below the overvoltage threshold value. When the voltage measurement value exceeds the overvoltage threshold value and the battery can be charged, the controller is configured to cause the fuel cell electric vehicle to continue traveling, while estimating the voltage at the direct current end using a second voltage sensor that measures output voltage of a fuel cell stack or a third voltage sensor that measures output voltage of the battery.

A method for discharging a vehicle high-voltage electrical system, which is galvanically isolated from a ground potential, in the presence of a residual current makes provision for the following step: determining whether a residual current flows between a first HV potential of the vehicle high-voltage electrical system and the ground potential or a residual current flows between a second HV potential of the vehicle high-voltage electrical system and the ground potential. The method furthermore makes provision to discharge only that Cy capacitance which exists between the ground potential and that HV potential from which or to which the residual current flows. The discharging is triggered by determining the existence of a residual current. Furthermore, an on-board vehicle electrical system and an insulation monitoring device which are designed for performing the method are described. In addition, a corresponding charging-station high-voltage electrical system is described.