Circuit/System Description
The hybrid/EV battery contains 3 high voltage contactors. The high voltage contactors allow the high voltage DC batteries to be connected to the vehicle or contain the high voltage DC within the hybrid/EV battery assembly. The high voltage contactors consist of a main positive high voltage contactor, main negative high voltage contactor and a precharge positive high voltage contactor. The contactors close and open in a specific sequence controlled by the hybrid/EV powertrain control module 2. The hybrid/EV powertrain control module 2 supplies 12V to the control circuit for each high voltage contactor.
The hybrid/EV powertrain control module 2 determines the high voltage system/battery voltage level in several ways:
- Monitoring the K112 hybrid/EV battery interface control module serial data for sense circuits that terminate at each individual hybrid/EV battery cell group.
- Summing the individual cell group voltage values to obtain a total hybrid/EV battery pack voltage.
- Monitoring sense circuits that terminate at the high voltage negative and positive battery connections of the A28 hybrid/EV battery contactor assembly.
- Monitoring the serial data high voltage value observed by the T6 power inverter module.
The hybrid/EV powertrain control module 2 may compare these values against each other to verify accuracy.