Abstract: A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

Abstract: Disclosed herein is a fault diagnosis apparatus of a rapid charging system for a vehicle including an external device configured to exchange power with a vehicle battery, a power transfer unit including a three-phase motor, an inverter connected to the battery in parallel and connected to the three-phase motor, and one or more relays connected to the three-phase motor and configured to transfer power between the external device and the battery, and a controller configured to control the on and off functions of the relay, to control driving of the inverter to generate voltages applied to one end of each of the relays, and to diagnose fault of relays by comparing voltages of both ends of the relays while turning the relays on/off.

Abstract: A fault diagnosis method of a power electric system for a vehicle may include driving an inverter to output an output voltage command for fault detection; measuring a current input to each phase of a motor connected to the inverter; measuring a voltage of the neutral stage of the motor; and determining whether there are faults of a connection member connecting between the inverter and the motor and a relay connected to the neutral stage of the motor based on the measured current input to each phase of the motor and the voltage of the neutral stage.

Abstract: A system for protecting an inverter in a vehicle from an overvoltage may include an inverter including a plurality of switching elements and converting energy supplied from an energy storage into AC power, a motor driven by the AC power converted by the inverter, a capacitor connected in parallel between the inverter and the energy storage and storing regenerative energy of the motor during regenerative braking, and a controller turning off a relay that connects the energy storage and the motor, when a voltage (DC-link voltage) of the capacitor measured by a voltage sensor is equal to or greater than a preset first voltage, and operating the switching elements in the inverter in response to a pre-stored current command (Id*, Iq*) to apply a zero vector to the motor.

Abstract: A charging system configured for reducing a leakage current may include an on board charger (OBC) receiving an alternating current (AC) power supplied from an external source to charge a vehicle battery with the AC power; at least an electric component connected to an output end portion of the OBC; at least a switch selectively connecting the electric component to or from a ground; and a controller connected to the at least a switch and reducing the leakage current flowing to the ground by controlling the switch connected to the electric component depending on whether or not the vehicle battery is charged with the AC power.

Abstract: A system for protecting an inverter in a vehicle from an overvoltage may include an inverter including a plurality of switching elements and converting energy supplied from an energy storage into AC power, a motor driven by the AC power converted by the inverter, a capacitor connected in parallel between the inverter and the energy storage and storing regenerative energy of the motor during regenerative braking, and a controller turning off a relay that connects the energy storage and the motor, when a voltage (DC-link voltage) of the capacitor measured by a voltage sensor is equal to or greater than a preset first voltage, and operating the switching elements in the inverter in response to a pre-stored current command (Id*, Iq*) to apply a zero vector to the motor.

Abstract: A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

Abstract: A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

Abstract: A system for diagnosing switching element selectively connecting Y-capacitors to ground is provided. The state of a switching device in a power conversion circuit is adjusted such that voltages of different levels are applied to the Y-capacitors, respectively. Therefore, a Y-capacitor disconnect switch which connects a plurality of Y-capacitors connected in common to a DC link to chassis ground is diagnosed.

Abstract: A system for diagnosing switching element selectively connecting Y-capacitors to ground is provided. The state of a switching device in a power conversion circuit is adjusted such that voltages of different levels are applied to the Y-capacitors, respectively. Therefore, a Y-capacitor disconnect switch which connects a plurality of Y-capacitors connected in common to a DC link to chassis ground is diagnosed.

Abstract: A fault diagnosis method of a power electric system for a vehicle may include driving an inverter to output an output voltage command for fault detection; measuring a current input to each phase of a motor connected to the inverter; measuring a voltage of the neutral stage of the motor; and determining whether there are faults of a connection member connecting between the inverter and the motor and a relay connected to the neutral stage of the motor based on the measured current input to each phase of the motor and the voltage of the neutral stage.

Abstract: A charging system configured for reducing a leakage current may include an on board charger (OBC) receiving an alternating current (AC) power supplied from an external source to charge a vehicle battery with the AC power; at least an electric component connected to an output end portion of the OBC; at least a switch selectively connecting the electric component to or from a ground; and a controller connected to the at least a switch and reducing the leakage current flowing to the ground by controlling the switch connected to the electric component depending on whether or not the vehicle battery is charged with the AC power.

Abstract: Disclosed herein is a fault diagnosis apparatus of a rapid charging system for a vehicle including an external device configured to exchange power with a vehicle battery, a power transfer unit including a three-phase motor, an inverter connected to the battery in parallel and connected to the three-phase motor, and one or more relays connected to the three-phase motor and configured to transfer power between the external device and the battery, and a controller configured to control the on and off functions of the relay, to control driving of the inverter to generate voltages applied to one end of each of the relays, and to diagnose fault of relays by comparing voltages of both ends of the relays while turning the relays on/off.