A method for operating an energy supply unit for a motor vehicle electrical system, including at least one first subsystem and one second subsystem having different voltage levels, the energy supply unit including an electric machine which is connected via a converter circuit to the first subsystem and the second subsystem. In a first operating mode, a switchable switch element of the converter circuit which connects the converter circuit to the second subsystem is opened, the converter circuit is activated as an inverter circuit and the electric machine is motor or generator operated. In a second operating mode, the switchable switch element of the converter circuit is closed, the converter circuit is activated as a DC-DC converter and the DC-DC conversion takes place between the voltage levels of the first and the second subsystem.

A power inverter including a multi-phase inverter circuit is electrically connected to a high-voltage DC power source, and includes a capacitor electrically connected between positive and negative conductors of a high-voltage bus. A normally-ON discharge switch is electrically connected in series with a discharge resistor between the positive and negative conductors of the high-voltage bus. The discharge switch includes a control gate, wherein the control gate of the discharge switch is in communication with an ignition switch. The discharge switch is controllable to an open state between the positive and negative conductors of the high-voltage bus when the ignition switch is in an ON state. The discharge switch achieves a closed state to provide a low-impedance electric current flow path through the discharge resistor between the positive and negative conductors of the high-voltage bus when the ignition switch is in an OFF state.

According to one aspect of the present disclosure, there is provided a power converter apparatus that includes at least two switching bridges connected to a Direct Current (DC) bus and both generating pulse-width-modulated (PWM) voltages to non-isolated outputs, and an isolation transformer having a primary winding connected across the outputs of the two switching bridges and a secondary winding connected to isolated outputs. In a non-isolated mode, the two switching bridges are configured to operate in a parallel mode, and power is transferred between the DC bus and the non-isolated outputs. In an isolated mode, the two switching bridges are configured to operate in a full bridge mode, and power is transferred between the DC bus and the isolated outputs through the transformer.

A control device for an electric vehicle, includes: a DC power supply; a three-phase AC motor; an inverter that converts DC power supplied from the DC power supply into AC power and outputs the AC power to the three-phase AC motor; and a control unit that controls the inverter to control an input voltage to the three-phase AC motor. Further, when a parameter correlated with the input voltage includes a predetermined high frequency component, the control unit performs correction of adding a component for canceling out the high frequency component to the input voltage, and controls the three-phase AC motor based on the corrected input voltage.

The invention relates to a voltage transformer (1) for transformation between a direct voltage at a direct voltage gate (2) and a single-phase or multi-phase alternating voltage at an alternating voltage gate (3) by temporal clocking of an electronic switching unit (4), via which each phase (3a-3c) of the alternating voltage gate (3) can be connected either to the positive pole or to the negative pole of the direct voltage gate (2), wherein the positive pole and/or the negative pole of the direct voltage gate (2) is connected via at least one capacitor (5, 5a, 5b) to a ground connection (7), wherein the ground connection (7) can be connected to an external ground (7a), and wherein the connection between the capacitor (5, 5a, 5b) and the ground connection (7) is guided via at least one switch element (6, 6a, 6b). The invention also relates to an electric powertrain (10) for a motor vehicle (100). The invention further relates to a motor vehicle (100) having the electric powertrain (10).

A vehicle power supply system includes two drive motors, a first power line to which a first inverter and a first battery are connected, a second power line to which a second inverter and a second battery are connected, a voltage converter that converts a voltage between these power lines, and a charging and discharging control device that controls charging and discharging of the batteries by operating the inverters and the voltage converter. In a case where a second SOC is equal to or greater than a second normal upper limit, the charging and discharging control device discharges power from the second battery to the second power line, and discharges a shortage of power from the first battery through the voltage converter to the second power line, wherein the shortage of power is obtained by excluding power discharged by the second battery from power required in the second power line.

The invention relates to a method for controlling an inverter which is electrically connected to an electric motor, having the following steps: defining a modulated voltage (S1) for the inverter, said voltage being based on a first switching frequency, for operating the electric motor with a current, wherein the current has an electric frequency; determining the electric frequency (S2); changing the first switching frequency (S4) on which the modulated voltage is based to a second switching frequency if a value pair consisting of electric frequency and first switching frequency, or a value pair consisting of electric frequency and a sideband of the first switching frequency, is within at least one defined disturbance range (S3).

Methods and systems are provided for controlling a high power output direct current to alternating current converter for a vehicle. In one example, a method may include at a vehicle-on event, automatically operating the converter in a first power output mode, and transitioning to a different mode of operation in response to a transition request being received at a controller of the vehicle. In this way, the different mode of operation may be subject to confirmation via an operator of the vehicle, which may improve operational performance of the direct current to alternating current converter.

A vehicle may include a motor including first, second, and third windings connected to the neutral node; an inverter including first switching elements, second switching elements, third switching elements; a battery configured to receive the boosted voltage; a first current sensor; a second current sensor; a third current sensor; and a controller may determine an average duty ratio of a pulse width modulated signal based on the charging voltage and battery voltage of the battery, and determine a duty ratio of a pulse width modulated signal, and the controller may determine the duty ratio of the pulse width modulated signal provided to the first switching elements based on the average duty ratio of the pulse width modulated signal provided to the inverter, to the second switching elements, and to the third switching elements when the first current sensor fails.

The invention relates to a method for controlling an inverter which is electrically connected to an electric motor, having the following steps: defining a modulated voltage (S1) for the inverter, said voltage being based on a first switching frequency, for operating the electric motor with a current, wherein the current has an electric frequency; determining the electric frequency (S2); changing the first switching frequency (S4) on which the modulated voltage is based to a second switching frequency if a value pair consisting of electric frequency and first switching frequency, or a value pair consisting of electric frequency and a sideband of the first switching frequency, is within at least one defined disturbance range (S3).