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 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.

Provided is an interlock device for a high voltage apparatus which enables not only the diagnosis of the connected or non-connected state of a connector during normal operation of the interlock device, but also the detection of a failure of the interlock device itself, including a failure of the interlock loop. The device includes an interlock loop 16 annexed to an HV connector 7 for connecting an electric compressor to an HV battery 8, a detecting signal output unit, a first switching element, a controlling voltage switching circuit operable, in a closed state of the interlock loop, to switch a voltage applied to a control electrode of the first switching element according to an output of the detecting signal output unit, a second switching element operable, in an open state of the interlock loop, to apply to the control electrode of the first switching element an output of the controlling voltage switching circuit so as to cause an ON/OFF state of the first switching element to be inverted from when the interlock loop is in the closed state, and a failure diagnosis unit.

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 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.

A method for detecting an insulation fault in a vehicle on-board electrical system having an HV on-board electrical system branch and an LV on-board electrical system branch provides for the LV on-board electrical system branch to have a positive supply potential and a negative supply potential that corresponds to a ground potential of the vehicle on-board electrical system. The HV on-board electrical system branch has a positive HV potential and a negative HV potential which are DC-isolated from the potentials of the LV on-board electrical system branch. An insulation fault between at least one of the HV potentials and a positive LV potential is detected by identifying a current flow through a voltage limiting circuit connected between the ground potential and the positive LV potential.

An electric power conversion system and a vehicle, to improve vehicle availability. The electric power conversion system may receive electric energy provided by a first power supply, and supply power to at least one load module. The system may include a first direct current to direct current conversion module and a second direct current to direct current conversion module. The first direct current to direct current conversion module is configured to perform voltage conversion processing on the electric energy and provide the electric energy to the at least one load module. The second direct current to direct current conversion module is configured to perform voltage conversion processing on the electric energy and provide the electric energy to the at least one load module.

A power conversion device includes a power converter, a relay, and a welding detector. The welding detector includes a first resistor connected to a terminal of the relay on a first side, a capacitor and a second resistor, both of which are connected to a terminal of the relay on a second side, an application unit to apply an inspection signal to the relay via the capacitor and the second resistor, and a determiner connected between the capacitor and the second resistor, the determiner detecting a signal based on application of the inspection signal by the application unit to determine whether or not the relay is welded.

A protection device for an electric DC grid includes a first protection circuit part including a series circuit consisting of a first discharge resistor and a first protection switch between a positive potential line and a reference potential line and a second protection circuit part including a series circuit consisting of a second discharge resistor and a second protection switch between a negative potential line and the reference potential line. The first and second protection switches can be actuated to close if a first and/or second voltage measuring device ascertains that a specified voltage value has been undershot and/or exceeded or the first and/or second protection switch can be actuated to close in an event of a fault current measured by a fault-current measuring device.

Devices, systems, and methods for constant and reliable power distribution, using a redundant power bridge battery architecture, in autonomous vehicles are described. An example method includes determining that each of a plurality of sensors is operating within in a nominal range for the respective sensor, and distributing, based on the determining, power from at least one alternating current (AC) power source or at least one direct current (DC) power source to at least one power distribution unit (PDU), wherein a first power bridge is coupled to the at least one AC power source and the at least one DC power source and a second power bridge is coupled to the at least one DC power source and the at least one PDU, and wherein the plurality of sensors is used to monitor a health of the vehicle and any single point failure is detectable.