Power distribution unit having contactor with integrated pre-charge circuit

A power distribution unit comprising:

• a housing having walls defining a main cavity and a secondary cavity;
• a main contactor received in the main cavity of the housing, the main contactor including first and second fixed contacts and a movable contact movable between a mated position and an unmated position, the movable contact engaging the first and second fixed contacts to electrically connect the first and second fixed contacts in the mated position, the movable contact being separated from the first and second fixed contacts in the unmated position, the main contactor including a coil assembly energized to move the movable contact between the unmated position and the mating position;
• a pre-charge assembly received in the secondary cavity of the housing, the pre-charge assembly including a pre-charge resistor and a pre-charge switch coupled to the pre-charge resistor and configured to be coupled to a pre-charge capacitor;
• and
• a controller received in the housing, the controller including a trigger connector electrically coupled to a control circuit board, the trigger connector configured to receive a trigger signal from a vehicle controller, the controller including a main contactor driver for powering the main contactor, the controller including a pre-charge driver for powering the pre-charge switch, the controller including a microcontroller mounted to the control circuit board, the microcontroller being operably coupled to the main contractor driver and operably coupled to the pre-charge driver, wherein the microcontroller activates the pre-charge driver upon receiving the trigger signal to charge the pre-charge capacitor prior to activating the main contactor driver.

A vehicle battery system comprising:

• a high voltage battery pack having a positive battery terminal and a negative battery terminal;
• an inverter configured to convert DC power from the high voltage battery pack to AC power for operating an electric motor of a vehicle;
• and
• a power distribution unit between the high voltage battery pack and the inverter, the power distribution unit comprising:
• a housing having walls defining a main cavity and a secondary cavity;
• a main contactor received in the main cavity of the housing, the main contactor including first and second fixed contacts and a movable contact movable between a mated position and an unmated position, the movable contact engaging the first and second fixed contacts to close the main contactor and electrically connect the high voltage battery pack with the inverter, the movable contact being separated from the first and second fixed contacts in the unmated position to open the main contactor, the main contactor including a coil assembly energized to move the movable contact between the unmated position and the mating position;
• a pre-charge assembly received in the secondary cavity of the housing, the pre-charge assembly including a pre-charge resistor and a pre-charge switch coupled to the pre-charge resistor and configured to be coupled to a pre-charge capacitor;
• and
• a controller received in the housing, the controller configured to receive a trigger signal from a vehicle controller, the controller including a main contactor driver for powering the main contactor, the controller including a pre-charge driver for powering the pre-charge switch, the controller including a microcontroller operably coupled to the main contractor driver and operably coupled to the pre-charge driver, wherein the controller activates the pre-charge driver upon receiving the trigger signal to charge the pre-charge capacitor prior to activating the main contactor driver.