SOC Estimator (Adaptive Kalman Filter) Block Inputs Definition

Hello everyone,

I would like to ask if somebody here knows about the units of the following inputs in SOC Estimator (Adaptive Kalman Filter) block:

https://de.mathworks.com/help/simscape-battery/ref/socestimatoradaptivekalmanfilter.html

1) CellTemperature - Is it Celsius or Kelvin?

2) InitialR0 - Is it in ohm or milliohm ? Also here, does this input refer to the terminal resistance of each cell or to the total terminal resistance of all cells in the case of a parallel cell assembly (e.g. 1s10p - a parallel cell assembly with 10 cells in parallel)?

Thanks!

Theo

Answer 1

[Xiangchun]

Hi Theodoros,

(1) CellTemperature can be in either K or C, as long as it is consistent with the unit of Vector of temperatures, T in the System Model.

(2) InitialR0 is in Ohm. Whether it is the terminal resistance of a single cell or the 1s10p parallel assembly depends on how the SOC estimation is set up. This block supports vectors for inputs. For example, we can input the voltage, current, temperature of each of the 10 cells to the block and all 10 of them at the same time, in which case the current is a 10 element vector. The block would then estimate the R0 and SOC for each single cell, and the estimated R0 is a 10 element vector. This is done by using For Each Subsystem Apply algorithm to individual elements or subarrays of input signals or mask parameters - Simulink (mathworks.com). On the other hand, if we input the total current and voltage of the 1s10p to this block, it will estimate SOC and R0 for 1s10p as a whole, in which case R0 is the terminal resistance for the parallel assembly and a scalar. In the latter case, the parameters in the System Model need to be specified to reflect that we are estimating the states/parameter for the 1s10p parallel assembly.

For details, please refer to the documentation page State of charge and terminal resistance estimator with adaptive Kalman filter - Simulink (mathworks.com), especially the "Ports" and "Parameters" sections.

Also, please fee free to "Look Under Mask" (Ctrl+U) of this block to see how it is implemented.

Best wishes,

Xiangchun