Description
The high voltage battery system consists of the BMS ECU (Battery Management System ECU), Power Relay Assembly (PRA), safety plug, battery temperature sensor, and battery ambient sensor. Especially the BMS ECU controls SOC (State Of Charge), power, cell balancing, cooling and troubleshooting of the high voltage battery system.
The PRA includes main relays (positive, negative), pre-charge relay, pre-charge resistor and battery current sensor.
Safety Plug is installed on the rear side of the high voltage battery and it can mechanically shut the high voltage circuit off when servicing the high voltage system (i.e. High Voltage Battery, Power Relay Assembly, HPCU, BMS ECU, Hybrid Drive Motor, Inverter, HSG, LDC, Power Cable, etc.). It includes a fuse in order to prevent the high voltage system from overcurrent.
Scheme 332
Main Relay is divided into the positive (+) relay and negative (-) relay. It is integrated into the Power Relay Assembly (PRA) and connects the power supply line and ground line between the high voltage battery and the inverter in accordance with the BMS ECU control signal.
Scheme 333
Scheme 334
![Scheme 334: [PRA Operation Sequence]](https://i.diagnostdata.com/repair/d1/d1a402d46e4eb817506f85f421073b25ae34071a2676412d3c3c4cb5e480a25a.webp)
Scheme 335
Pre-Charge Relay is integrated into the Power Relay Assembly (PRA). It starts to charge the capacitor of the inverter soon after IG ON, then it is turned off after the capacitor has been fully charged.
Scheme 336
Scheme 337
![Scheme 337: [PRA Operation Sequence]](https://i.diagnostdata.com/repair/bb/bb4be3f08fd4c6612edad8428b755d6511c43f0bcade797038221b399fa4447d.webp)
Scheme 338
Pre-Charge Resistor is integrated into the Power Relay Assembly (PRA). It protects the high voltage circuit by limiting the current while the inverter capacitor is being charged.
Scheme 339
Battery Current Sensor is integrated into the Power Relay Assembly (PRA) and measures the current of the high voltage battery during charging or discharging.
Scheme 340
The main fuse is mounted in the safety plug and protects the high voltage battery and high voltage circuits from overcurrent.
Battery Temperature Sensor is installed inside the high voltage battery pack assembly. It measures the temperature of the battery module 1, 3, 5, 7, 9 and air inlet.
In addition, it integrates the voltage sensing wiring for each module.
Scheme 341
Battery Ambient Sensor is installed on the auxiliary battery and measures the ambient temperature of the high voltage battery.
