How do i write to the base workspace in simulink?

I currently have:

BatteryParams = struct();
for idx = 1:numCells

      %%Lookup Table Breakpoints
      BatteryParams(idx).SOC_LUT = [0 0.1 0.25 0.5 0.75 0.9 1]';
      BatteryParams(idx).Temperature_LUT = [5 20 40] + 273.15;

      %%Em Branch Properties (OCV, Capacity)

      % Battery capacity
      BatteryParams(idx).Capacity_LUT = [
          80.0000   79.5000   79.0000]; %Ampere*hours

From my GUI i want to change the "BatteryParams(idx).Capacity_LUT" in the workspace while running the simulation.

I have gotten a hint to these functions but otherwise I am unsure of how to proceed.

command = sprintf('BatteryParams(%d).Capacity_LUT = %f;', idx, value)
evalin('base', command);

I am guessing I have to use the "to workspace" block in simulink but other than what i have written here now i am kinda blank on the sollution to my problem.

Can anyone help me out ?

[Ajay Kumar P]

Please try using assignin('base','varibale name',value) function to create/update variable values in the base workspace.

[Stephen23]

Although global and assignin will work, they are also very difficult to debug and make code-checking almost impossible. It is reccomended to pass values as much as possible, which means they should be collected and passed as output arguments.

This page has more information on this topic:

http://www.mathworks.com/help/matlab/matlab_prog/share-data-between-workspaces.html

Answer 1

[Navaneeth Raman]

Hello,

Can you be clear on how you have your model setup and how the above code ties in within your system? Its not clear where your code fits in.

Thanks, Navaneeth

[Roy Hauge]

The complete file for the various values are:

 % Initialization file for demo ssc_lithium_battery_80Cells.mdl. 
  %
  % Demo based on model from publication: T. Huria, M. Ceraolo, J. Gazzarri,
  % R. Jackey. "High Fidelity Electrical Model with Thermal Dependence for
  % Characterization and Simulation of High Power Lithium Battery Cells,"
  % IEEE International Electric Vehicle Conference, March 2012
  %
  % Copyright 2012 The MathWorks, Inc.

% Number of series cells
numCells = 96;

%%Thermal Properties
% Cell dimensions and sizes
cell_thickness = 0.0084; %m
cell_width = 0.215; %m
cell_height = 0.220; %m

% Cell surface area
cell_area = (...
    cell_thickness * cell_width +...
    cell_thickness * cell_height +...
    cell_width * cell_height); %m^2

% Cell volume
cell_volume = cell_thickness * cell_width * cell_height; %m^3

% Convective heat transfer coefficient
% For natural convection this number should be in the range of 5 to 25
h_conv = 5; %W/m^2/K Cell-to-cell
h_conv_end = 10; %W/m^2/K End cells to ambient

% String1
Init = 0; % SOC adjustment

% String2
Init1 = 0; % SOC adjustment

%%Populate Lookup Tables
BatteryParams = struct();
for idx = 1:numCells

      %%Lookup Table Breakpoints
      BatteryParams(idx).SOC_LUT = [0 0.1 0.25 0.5 0.75 0.9 1]';
      BatteryParams(idx).Temperature_LUT = [5 20 40] + 273.15;

      BatteryParams(idx).SOC_LUT1 = [0 0.1 0.25 0.5 0.75 0.9 1]';
      BatteryParams(idx).Temperature_LUT1 = [5 20 40] + 273.15;

      %%Em Branch Properties (OCV, Capacity)

      % Battery capacity
      BatteryParams(idx).Capacity_LUT = [
          80.0000   79.5000   79.0000]; %Ampere*hours

      BatteryParams(idx).Capacity_LUT1 = [
          80.0000   79.5000   79.0000]; %Ampere*hours

      % Em open-circuit voltage vs SOC rows and T columns
      BatteryParams(idx).Em_LUT = [
          2.0000    2.9474    3.0000
          3.0526    3.1055    3.1579
          3.2105    3.2632    3.3158
          3.3684    3.4211    3.4737
          3.5263    3.5789    3.6315
          3.6842    3.7368    3.7895
          3.9421    4.0947    4.1473]; %Volts

      BatteryParams(idx).Em_LUT1 = [
          2.0000    2.9474    3.0000
          3.0526    3.1055    3.1579
          3.2105    3.2632    3.3158
          3.3684    3.4211    3.4737
          3.5263    3.5789    3.6315
          3.6842    3.7368    3.7895
          3.9421    4.0947    4.1473]; %Volts

      %%Terminal Resistance Properties

      % R0 resistance vs SOC rows and T columns
      BatteryParams(idx).R0_LUT = [
          0.0117    0.0085    0.0090
          0.0110    0.0085    0.0090
          0.0114    0.0087    0.0092
          0.0107    0.0082    0.0088
          0.0107    0.0083    0.0091
          0.0113    0.0085    0.0089
          0.0116    0.0085    0.0089]; %Ohms

      BatteryParams(idx).R0_LUT1 = [
          0.0117    0.0085    0.0090
          0.0110    0.0085    0.0090
          0.0114    0.0087    0.0092
          0.0107    0.0082    0.0088
          0.0107    0.0083    0.0091
          0.0113    0.0085    0.0089
          0.0116    0.0085    0.0089]; %Ohms

      %%RC Branch 1 Properties

      % R1 Resistance vs SOC rows and T columns
      BatteryParams(idx).R1_LUT = [
          0.0109    0.0029    0.0013
          0.0069    0.0024    0.0012
          0.0047    0.0026    0.0013
          0.0034    0.0016    0.0010
          0.0033    0.0023    0.0014
          0.0033    0.0018    0.0011
          0.0028    0.0017    0.0011]; %Ohms

      BatteryParams(idx).R1_LUT1 = [
          0.0109    0.0029    0.0013
          0.0069    0.0024    0.0012
          0.0047    0.0026    0.0013
          0.0034    0.0016    0.0010
          0.0033    0.0023    0.0014
          0.0033    0.0018    0.0011
          0.0028    0.0017    0.0011]; %Ohms

      % C1 Capacitance vs SOC rows and T columns
      BatteryParams(idx).C1_LUT = [
          1913.6    12447    30609
          4625.7    18872    32995
          23306     40764    47535
          10736     18721    26325
          18036     33630    48274
          12251     18360    26839
          9022.9    23394    30606]; %Farads

      BatteryParams(idx).C1_LUT1 = [
          1913.6    12447    30609
          4625.7    18872    32995
          23306     40764    47535
          10736     18721    26325
          18036     33630    48274
          12251     18360    26839
          9022.9    23394    30606]; %Farads

      % Cell mass
      BatteryParams(idx).cell_mass = 1; %kg

      % Volumetric heat capacity
      % assumes uniform heat capacity throughout the cell
      % ref: J. Electrochemical Society 158 (8) A955-A969 (2011) pA962
      BatteryParams(idx).cell_rho_Cp = 2.04E6; %J/m3/K

      % Specific Heat
      BatteryParams(idx).cell_Cp_heat = BatteryParams(idx).cell_rho_Cp * cell_volume; %J/kg/K

      %%Initial Conditions
      % Charge deficit
      % BatteryParams(idx).Qe_init = 15.6845; %Ampere*hours

      % Ambient Temperature
      BatteryParams(idx).T_init = 20 + 273.15; %K

      BatteryParams(idx).T_init1 = 20 + 273.15; %K

      % Initial charge deficit
      BatteryParams(idx).Qe_init = 0; %Ampere*hours

      BatteryParams(idx).Qe_init1 = 0; %Ampere*hours

      %%Cell Variation

      % Tweak resistances and capacitances
      BatteryParams(idx).R0_LUT = BatteryParams(idx).R0_LUT * (1 + .1*(rand-0.5));
      BatteryParams(idx).R1_LUT = BatteryParams(idx).R1_LUT * (1 + .1*(rand-0.5));
      BatteryParams(idx).C1_LUT = BatteryParams(idx).C1_LUT * (1 + .1*(rand-0.5));

      BatteryParams(idx).R0_LUT1 = BatteryParams(idx).R0_LUT1 * (1 + .1*(rand-0.5));
      BatteryParams(idx).R1_LUT1 = BatteryParams(idx).R1_LUT1 * (1 + .1*(rand-0.5));
      BatteryParams(idx).C1_LUT1 = BatteryParams(idx).C1_LUT1 * (1 + .1*(rand-0.5));
This is the complete file i am currently working with.      

      % Tweak initial charge deficit
      BatteryParams(idx).Qe_init = 5 * rand; %Ampere*hours

      BatteryParams(idx).Qe_init1 = 5 * rand; %Ampere*hours
  end

The block where I implement the variables I wish to change has the following code:

component Em_tableMod
% Em_tableMod
% This block implements the cell's main branch voltage source, and determines
% values for capacity (C) and state of charge (SOC). The defining equations
% depend on cell temperature, T.

% Copyright 2012-2013 The MathWorks, Inc.

      nodes
          p = foundation.electrical.electrical; % +:left
          n = foundation.electrical.electrical; % -:right
      end

      inputs
          C = {79.5,'A*hr'} % Cap:right
          T = {293.15,'K'} % T:right
      end

      outputs
          SOC = {1,'1'}   %SOC:left
      end

      parameters (Size=variable)
          Em_Table = {3.8*ones(5,3),'V'} % Matrix of voltage values, Em(SOC,T)
          SOC_Table = {[0;0.1;0.5;0.9;1],'1'} % State of charge (SOC) breakpoints
          Temp_Table = {[273.15 293.15 313.15],'K'} % Temperature (T) breakpoints

      end

      parameters
          Qinit = {0,'A*hr'} % Initial charge deficit
      end

      variables(Access=private)
          i = { 0, 'A' };  % Current
          v = { 0, 'V' };  % Voltage
          Qe = {0,'A*hr'}; % Charge deficit
      end
      function setup

          % Check parameter values
          if any(any(value(Em_Table,'V')<=0))
              pm_error('simscape:GreaterThanZero','Matrix of voltage values, Em(SOC,T)');
          end
          if any(value(SOC_Table,'1')<0)
              pm_error('simscape:GreaterThanOrEqualToZero','State of charge (SOC) breakpoints');
          end
          if any(value(Temp_Table,'K')<0)
              pm_error('simscape:GreaterThanOrEqualToZero','Temperature (T) breakpoints');
          end
          if value(Qinit,'A*hr')<0
              pm_error('simscape:GreaterThanOrEqualToZero','Initial charge deficit');
          end

          % Set initial charge deficit
          Qe = Qinit;

      end

      branches
          i : p.i -> n.i;
      end

      equations

          v == p.v - n.v;

          % Charge deficit calculation, preventing SOC>1
          if Qe<0 && i>0
              Qe.der == 0;
          else
              Qe.der == -i;
          end

          % SOC Equation
          SOC == 1 - Qe/C;

          % Electrical equation by table lookup
          v == tablelookup(SOC_Table,Temp_Table,Em_Table,SOC,T,...
              interpolation=linear,extrapolation=nearest)

      end

end

I have modified the block so I can adjust the capacity directly as an input as i asked for but I still need a way to adjust the SOC to a certain level during simulation which is basically the same problem. To workspace doesnt work since it doesnt implement the changes to workspace live.