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.

In accordance with at least one aspect of this disclosure, there is provided a system for aircraft power. The system includes a DC/DC converter having a DC input and a DC output and a switching circuit connecting the DC input to the DC output operable to vary voltage at the DC output. A control module is operatively connected to the switching circuit for variable control of the DC output. The control module includes machine readable instructions to cause the control module to receive input indicative of altitude and control the switching circuit to vary voltage of the DC output as a function of environmental conditions such as altitude and humidity. In embodiments the altitude sensor is operatively connected to the controller.

Provided are an insulation detection method and apparatus for a fuel cell vehicle, and a vehicle. The method comprises: determining whether a vehicle is started; when the vehicle is started, executing the following steps: controlling a battery management system to perform the first insulation detection; detecting whether a fuel cell is started; and when the fuel cell is not started, controlling a fuel cell control unit to perform second insulation detection, wherein an insulation detection module for performing insulation detection on the fuel cell is provided in the fuel cell control unit of the vehicle.

An insulation fault response method for a fuel cell vehicle, comprising: when a vehicle starts, detecting whether a fuel cell is in a startup state or not; when the fuel cell is not in the startup state, reading a first insulation resistance detected by a fuel cell control unit and a second insulation resistance detected by a cell management system; when the first insulation resistance indicates that the vehicle is in an insulation fault, executing a first control policy; and when the second insulation resistance indicates that the vehicle in an insulation fault, executing a second control policy, wherein the first control policy is different from the second control policy, and wherein when the first insulation resistance is less than a first threshold and/or the second insulation resistance is less than a second threshold, the vehicle is in an insulation fault.

A vehicle power supply device converts power from high voltage to low voltage by selectively connecting a predetermined power storage element group to a low voltage electric load from a high voltage power supply formed by connecting power storage elements in series. A leakage current from the high voltage power supply is measured during the dead time period when the power storage element group is not connected to the low voltage electric load. When the value exceeds a predetermined value, the connection between the power storage element group and the low-voltage electric load is interrupted, so that electric shock is prevented.

An energy monitoring system for discharging energy in an energy transfer device of a vehicle, including an isolation monitoring unit, a capacitor unit, a voltage terminal unit and a control unit. The voltage terminal unit is connectable to an energy storage system and transfers energy from the energy storage system to a vehicle subsystem. The isolation monitoring unit includes a first isolation resistor element and switch element. The resistor element is connectable to the voltage terminal unit via the switch element. The capacitor unit is connected to the voltage terminal unit and filters electromagnetic interference by storing energy during energy transfer to the subsystem. The control unit closes the first isolation switch element in case of a disconnection of the energy transfer to form a discharge circuit connecting the isolation monitoring unit and the capacitor unit. The discharge circuit discharges energy stored in the capacitor unit.

A failure in any of first switches is determined based on a voltage value of a battery assembly and a predetermined threshold. The voltage value is retained in a capacitor by turning on or off the first switches and a second switch, and obtained from a voltage detector a voltage value.

A vehicle power supply device converts power from high voltage to low voltage by selectively connecting a predetermined power storage element group to a low voltage electric load from a high voltage power supply formed by connecting power storage elements in series. A leakage current from the high voltage power supply is measured during the dead time period when the power storage element group is not connected to the low voltage electric load. When the value exceeds a predetermined value, the connection between the power storage element group and the low-voltage electric load is interrupted, so that electric shock is prevented.

A charging system for an autonomous rover includes a charging interface with contacts that interface with the autonomous rover, a rover power source for the autonomous rover, and circuitry operated by the autonomous rover for controlling charging of the rover power source.

A ground impedance and fault detection system may include a controller that can identify a location of a ground fault in a circuit. The circuit also may include one or more positive contactors connected with a positive portion of the bus between battery strings and a load and a negative bus contactor coupled with a negative portion of the bus between the battery strings and the loads. The controller may identify the ground fault by opening the one or more positive contactors and closing the negative bus contactor, measuring the voltages using the impedance devices, and comparing the voltages that are measured.