4.1.1.7. SOF: Trapezoid

4.1.1.7.1. Module Files

4.1.1.7.1.1. Driver

src/app/application/algorithm/state_estimation/sof/trapezoid/sof_trapezoid.c (API, source)
src/app/application/algorithm/state_estimation/sof/trapezoid/sof_trapezoid.h (API, source)

4.1.1.7.1.2. Configuration

src/app/application/algorithm/state_estimation/sof/trapezoid/sof_trapezoid_cfg.c (API, source)
src/app/application/algorithm/state_estimation/sof/trapezoid/sof_trapezoid_cfg.h (API, source)

4.1.1.7.1.3. Unit Test

tests/unit/app/application/algorithm/state_estimation/sof/trapezoid/test_sof_trapezoid.c (API, source)
tests/unit/app/application/algorithm/state_estimation/sof/trapezoid/test_sof_trapezoid_cfg.c (API, source)

4.1.1.7.2. Detailed Description

The state of function estimation (SOF) calculates current derating values to operate the battery system within the safe operating area. These charge and discharge derating values are calculated according to battery cell specific and battery system related constraints.

For this, the operating limits for the cell voltage and cell temperature are taken into account. Two derating points are defined for each of these limits. A cut-off value where the derating begins and the allowed current starts to be decreased and a limit value where no current flow is allowed anymore. The allowed current is linearly decreased between these two points.

Additionally, the electrical string current capability are consider and the allowed current is limited below this value. This value needs to be configured according to the design of the battery system. Important factors for this are for example the selected contactors and connectors or the busbar/wire cross section.