Description And Operation - Battery Cooling System: Notes
DESCRIPTION - ENTIRE COOLING SYSTEM
The Plug-In Hybrid Electric Vehicle (PHEV) heating and cooling requirements are managed with a combination of three cooling system loops and the vehicles HVAC refrigerant system to provide temperature control of the gas engine, passenger compartment, high voltage battery, power electronics, turbocharger system and transmission cooling systems. The 3 cooling systems are, Engine Coolant Loop (Orange), Battery Coolant Loop (Green), and Low Temperature Coolant Loop (Red).
- The High Temperature Engine Coolant Loop (Orange) consists of a Coolant Heater connected to the high voltage system, and an Electric Coolant Pump in addition to the traditional gasoline engine cooling system. The high temperature engine cooling loop can maintain proper engine temperature when the engine is running as well as provide heat to the passenger compartment when the engine is not operating.
- The Low Temperature Coolant Loop (Red) removes heat generated by the electric drive controls, turbocharger system and also has a heat exchanger to provide transmission cooling.
- The Battery Coolant Loop (Green) obtains heat from the High Voltage Coolant Heater in the Engine Cooling Loop or disperses heat through a chiller valve in the HVAC refrigerant system.
- The HVAC refrigerant system can function when the engine is not operating to remove heat from the passenger compartment and the high voltage battery coolant.
DESCRIPTION - BATTERY COOLING SYSTEM
| 1 - Secondary HV Battery | 4 - Pressurized Coolant Bottle |
| 2 - Primary HV Battery | 5 - Chiller Valve |
| 3 - Battery Coolant Heater | 6 - Battery Coolant Pump |
DESCRIPTION: The Battery Cooling System is a separate low pressure (5 psi) system used to maintain temperature control of the high voltage battery pack. The system consists of a chiller valve, battery coolant pump, battery coolant heater and split high voltage batteries.
| 1 - A/C Evaporator | 6 - Chiller Valve |
| 2 - Front Refrigerant Shut-off Valve | 7 - Battery Coolant Pump |
| 3 - Expansion Valve | 8 - Battery Coolant Heater |
| 4 - 300 Volt Electric A/C Compressor | 9 - Primary HV Battery |
| 5 - A/C Condenser | 10 - Secondary HV Battery |
OPERATION:
The Battery Pack Control Module (BPCM) maintains the high voltage battery internal temperature at an optimum operating range. The battery coolant pump circulates the coolant through the entire battery cooling system. The battery coolant heater or chiller valve are controlled to either heat or cool the HV battery depending on ambient temperature and battery internal temperature. When the ambient temperature and internal battery temperature are cold the battery coolant heater is used to heat the coolant and bring the HV battery pack to optimal operating temperature. When the battery internal temperature increases to the high threshold the coolant passes through the chiller valve to dissipate heat from the system.
- The battery coolant heater is connected to a HV cable from the BPCM. The battery coolant heater is provided battery power from a relay and a chassis ground. The battery coolant pump is provided battery power and a chassis ground. The BPCM controls the operation of the battery coolant heater and the battery coolant pump using a common LIN bus communication line.
- The chiller valve performs the operation of a radiator for the battery cooling system. The chiller valve is provided battery power and a chassis ground. The PIM controls the operation of the chiller valve, electric coolant heater used in the engine cooling system, and the electric A/C compressor using a common LIN bus communication line. The electric A/C compressor is used to circulate freon throughout the entire A/C system. Freon from the A/C system is circulated to the chiller valve. When battery cooling is needed, the PIM commands the chiller valve to open allowing Freon to flow through the chiller valve removing heat from the coolant in the battery cooling system.