HV BUS 3
Battery types
18650, 2170, 4680
Charge Port Interlock Loop
5 volt digital signal that is used to validate HV cables and components
CPIL
5 volt signal used to validate charging HV cables and components Only prevents the vehicle from charging
Pilot
Allows the EVSE to indicate available current draw to the vehicle
DC link side
Anything after the contactor
Pack side
Anything before the contactor
BMS
Brain of the HV battery, data link between the HV battery and the vehicle
HV shunt
Busbar of known and precise resistance that measure current
KET dummy plugs testing
Bypasses the component in question, quickly diagnoses isolation
BMB
Connects to cells and measures cell voltage and temperature
PCS function
Converting AC to DC and stepping it up to charge the HV battery form AC wall power Converting DC high voltage to low voltage to support the low voltage battery Precharge HV bus prior to closing the contactors
Inverter
Converts DC battery power to 3 phase A/C Brains of the drive unit
Coolant is used for
Cool down components, takes thermal energy from one location to another
Drive units cooled two ways
Directly or through heat exchange
HVIL internal loop
First half of the traditional HVIL circuit
Pilot
Generated by the EVSE to tell the vehicle the maximum AC line current it is allowed to draw Job is to communicate with the vehicle using a duty cycle and a voltage
Battery Coolant Heater
Heats the coolant by passing energy through a resistor
Healthy Isolation
High value, meaning there is no risk for HV to be present on the chassis
Contactors
High voltage relay of sorts that separates HV from the battery pack to the HV components on DC link side of the HV bus
Excessive voltage
Increases resistance
resolvers
Measure the angle of the rotor
Isolation Resistance
Measurement of resistance between HV + and HV - to the vehicle frame ground or chassis
Pilot and Proximity
Most common failure of UMCs
encoders
Normal speed sensor like a crankshaft position sensor
Thermal fuse
Opens HV loop due to high current
Thermal modes
Passive Heating and Cooling Active heating and cooling
LV system power source
Power conversion system (DCDC) Low voltage battery (LV)
Model 3/Y HV/LV devices
Power conversion system (includes DCDC) High voltage controller Drive inverters (front and rear) HVAC compressor
Insulation meter Testing
Pressure tests system looking for current leaking back to ground, high voltage resistance check
Lockout procedure
Prevent the vehicle from engaging or powering up
HVIL
Protect the operator and equipment System made to make sure HV connections are connected Low voltage series circuit system 20mA current driven
Isolation resistance
Resistance between HV + and HV- to chassis ground Pathway to ground of known resistance used to monitor other potential high voltage shorts
Precharge
Safety check when HVIL is satisfied Sequence that allows for slowly charging up capacitors Equalize voltage on DC link side and pack side Prevents current inrush when contactors close to protect the contactors
Charge port
Serves as the connection point between the charge port and the vehicle
Proximity
Signal to indicate that a charge cable is connected to the vehicle
DCDC
Step-down Battery High Voltage to supply the vehicle's low voltage system and recharge the 12V battery
HVIL
System ensure all HV connections are connected prior to closing the contactors Protectors the operator and equipment Basic series circuit with switches, jumpers, and resistors powered by the HVP Driven by a constant 20ma current
External isolation
The resistance between the HV and chassis ground when the pack contactors are closed
Internal isolation
The resistance between the HV and chassis ground when the pack contactors are opened
Induction drive unit
The stator induces current into the rotor that opposes the Stator
Hi-Pot test
Tool used to load test electrical circuit good for intermittent isolation faults
Hi- pot testing
Tool used to load test the electrical circuit , -Good for intermittent isolation faults
FC CAN
Used in fast charging done by single wire CAN
Heat
Voltage trending downward usually caused by
PTC heater
Warms the cabin by passing energy through a resistor
Insulation meter
high voltage resistance check pressure tests system looking for current leaking back to ground Shoots DC link system with
ket dummy plugs
quick way to physically diagnose isolation bypasses component in question
HVIL vehicle loop
second half of the traditional HVIL circuit
permanent magnet
the permanent magnets inside the motor have a pre established magnetic field
Tesla vehicles use two coolant loops
•Battery loop •Powertrain loop
Heating the HV Battery benefits
•Faster charging •Higher amperage charging when cold
Motor
•Has the rotor and stator •Makes torque
Cooling the HV Battery benefits
•Higher amperage charging •Increases battery life
Cooling the Chargers
•Higher charge rates for extended time
Cooling the Drive Inverter and Motor benefits
•Higher current draw •Used during acceleration or regeneration
3 induction drive units
•Large Rear •Small Rear Small front
Cooling Car Computer
•Prevents overheating on processors
Common coolant modes are
•Series •Series - Radiator bypass •Parallel •Ambient Source
Gearbox
•Takes motor torque and amplifies it through a gear reduction
Battery Heating - series mode
•Used during cold soak conditions •Coolant flows through the motor to heat coolant
parallel mode
•Used in high ambient temperatures •HV Battery runs on its own loop while powertrain also runs on its own loop
high powertrain cooling - series mode
•Used in high ambient temperatures •HV battery can act as a thermal capacitor to absorb powertrain heat
Reduced Cooling Energy - series mode
•Used in low ambient temperatures •Allows coolant to flow through the radiator to cool the battery
Waste heat mode
(VCFRONT) sends a request to the drive inverter to produce the necessary power that is required to heat the coolant
Drive unit sections
-Inverter -Motor -Gearbox
3 permanent magnet units
-Permanent Rear -Permanent Front -Double Permanent Rear
Proximity
-Tells us if charge cable is physically connected or not -Cables have a specific resistance that effects a voltage divider circuit
Pyro disconnect
-Triggered by Restraint control module if crash is detected, or if unexpected conditions can compromise powertrain hardware -Over-current, overcharge, over discharge, airbag deployment -Controlled by the HVC
