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 testing apparatus for testing electrical components and/or conductor track structures. The testing apparatus includes: a multiplicity of testing locations, each receiving an electrical component and/or a conductor track structure; a selection device for selecting one of the testing locations; electrical lines disposed in rows and electrical lines disposed in columns for the supply of an alternating voltage to the component or structure, situated at the selected testing location; Z diodes for the electrical connection of the respective component and/or structure at the respective testing location via one of the Z diodes to one of the rows of electrical lines; a signal generator developed to generate a test signal that has a voltage signal as the sum of a square wave signal and a wave-shaped signal; and an electromigration device for applying a direct voltage signal to the components and/or structures to bring about electromigration in the components and/or structures.

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 ground fault detection device compatible with Y capacitors of various capacities without increasing the capacitance of a detection capacitor is provided. The ground fault detection device includes a first detection capacitor that operates as a flying capacitor, a second detection capacitor that operates as a flying capacitor, a control unit measures the charging voltage of the first detection capacitor and the second detection capacitor, a switching unit that switches between a state using a first measurement system in which the first detection capacitor is charged with the high voltage battery and the charging voltage of the first detection capacitor is measured by the control unit, and a state using a second measurement system in which the second detection capacitor is charged with the high voltage battery and the charging voltage of the second detection capacitor is measured by the control unit.

A method for estimating the usable charge capacity of an electrical energy store includes determining a nominal initial charge capacity and a maximum initial estimation error of a new or slightly degraded energy store; determining one or more nominal charge capacities and one or more maximum estimation errors for the degraded energy store; interpolating a graph for the nominal charge capacity and for the maximum lower and upper estimation errors between the interpolation points of the nominal charge capacity and the interpolation points of the maximum estimation errors; and estimating a nominal charge state, a current usable charge capacity with a lower estimation reserve, and a current usable charge capacity with an upper estimation reserve for a current degradation state of the electrical energy store.

Provided herein are approaches for determining a status of a fuse. In some embodiments, a system may include a first fuse electrically connected to a first node and to a first resistor, and a second fuse electrically connected to a second node and a second resistor, wherein the first and second fuses are in parallel connection to a same port of a multiplexer. The system may further include a controller communicably connected with the multiplexer, the controller operable to read a voltage level of the first and second nodes.

Provided herein is a power distribution system comprising a main power bus, sub-buses coupled to the main power bus, and a controller. The sub-buses provide power to electrical components of a vehicle. Each of the sub-buses includes an electrically programmable fuse in series with a relay. The controller is configured to detect a fault in a sub-bus of the sub-buses, determine a fault type associated with the fault, and in response to determining the fault type, generate a command to cause the relay to change a relay state.

Provided is a load drive device capable of diagnosing a failure of an output terminal of the load drive device before a charging voltage stabilizes in a configuration in which a capacitor is connected to an output terminal of the load drive device that drives an inductive load. In the load drive device according to the present invention, a capacitor is connected between a load terminal and a ground terminal, and the presence or absence of a failure of the load terminal is diagnosed on the basis of a current flowing between an internal power supply included in a diagnosis circuit and the load terminal.

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.

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.