BMS: Battery Management System
The BMS evaluates the measurement around the battery system and combines it with user requests to operate the battery.
| component | component dialog | parameters |
|---|---|---|
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property tabs
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Block Diagram
The BMS is internally a C-function that evaluates inputs from the user (e.g. set points) and measurements (voltage, current, temperature) of the battery system. Limits are defined in the mask and cover the follwing questions:
- Current limit contains a soc dependent maximum current that is most relevant for DC fast charging and is special for every EV, see also ev twin.
- Battery voltage limits (min and max)
- Battery temperature operation range
The resulting states are used to control the contactors in Power Unit. For details see section Inputs and Outputs.
Modes and States are predefined via constants:
POWER_MODE_ERROR = -1
POWER_MODE_OFF = 0
POWER_MODE_AC = 1
POWER_MODE_DC = 2
POWER_MODE_DRIVING = 3
#Mode Battery
BATTERY_MODE_ERROR = -1
BATTERY_MODE_DISABLE = 0
BATTERY_MODE_ENABLE = 1
BATTERY_MODE_VENT = 2
#BMS STATUS
BMS_STATE_ERROR_TEMPERATURE = -4
BMS_STATE_ERROR_VOLTAGE = -3
BMS_STATE_ERROR_CURRENT = -2
BMS_STATE_ERROR = -1
BMS_STATE_OFF = 0
BMS_STATE_AC_CHARGE = 10
BMS_STATE_AC_CHARGE_LIMITED = 11
BMS_STATE_DC_CHARGE = 20
BMS_STATE_DRIVING = 30
AUTO_RESET = 1
Inputs and Outputs
Input
| Number | Input | Description | range | default |
|---|---|---|---|---|
| 1 | mode bat | Battery mode, enabling battery | 0 | |
| 2 | mode power | Power mode: AC, DC, Driving, ... | ||
| 3 | reset | Reset of BMS | ||
| 4 | conditioning | enabling battery conditioning | True, False | False |
| 5 | Ibat | battery current | ||
| 6 | voltage | battery voltage | ||
| 7 | soc | battery state of charge | ||
| 8 | temperature | battery temperature |
Output
| Number | Output | Description | range | default |
|---|---|---|---|---|
| 1 | cont | list of states for the contactors [AC, DC, driving] | ||
| 2 | condition | voctor [enabling conditioning, current conditioning] | ||
| 3 | bat_status | status of battery | ||
| 4 | BMS_STATE | status message of BMS | ||
| 5 | Ilim | current limit for current | ||
| 6 | lmits | vector of other limits [ Vbat min, Vbat max, T min, T max] |
Dialogue box and Parameters
The BMS subsystem is organized in three tabs.
Tab 1 - General
| Parameter | Code Name | Description |
|---|---|---|
Tab 2 - Current limit
| Parameter | Code Name | Description |
|---|---|---|
Tab 3 - limits
| Parameter | Code Name | Description |
|---|---|---|