BPS Architecture
The BPS (Battery Protection System) monitors the voltage, current, and temperature of the Main Battery Pack to ensure it remains in a safe state.
Relevant Regulations
TODO
Hardware Components
VoltTemp Board
1 per battery segment, 8 total boards for battery configuration
Measures voltage across 4 series battery modules per segment (total 14.4V)
Measures temperature of battery modules by interfacing with flex thermistor collector
Interfaces with PSOM to send data on PCAN_BPS
Thermistor Collector Board
Flexible PCB with 4 thermistors to measure temperature of each battery module
Interfaces with VoltTemp to measure temperature via ADC
Amperes Board
Measures total battery current using low side shunt resistor (on HV- line)
Onboard MCU, due to sizing and enclosure constraints (no SOM)
Sends current data over PCAN_BPS
BPS Leader Board
Reads data from Amperes and VoltTemp over PCAN_BPS
Interfaces with CarCAN to send fault messages, important BPS messages (charging, trip, safe)
Runs control loop for battery box fans (fan controller via I2C)
Handles precharge and contactor control for array and battery HV contactors
Indication Board
Houses 5 addressable LEDs to indicate the status of the battery pack
HV Active LED, BPS Fault, etc.
Scrutineering Board
Allows for injection of arbitrary voltages to test BPS voltage, current, and temperature setpoints
Connects to 2 VoltTemp boards to inject voltages/temperatures into 2 distinct modules
Connects to Amperes to simulate charge/discharge current
Software Architecture
TODO