Matrix dimensions must agree. Error in Untitled (line 22) E_net=E_PV-L; ..........​..........​.....error in subtract op,,,,

%%(1)Data sources

fileName = 'PVModelingBookDataSource.xls';

sheetName = 'Source 2';

G= xlsread(fileName, sheetName , 'A1:A8761');

T= xlsread(fileName, sheetName , 'B1:B8761');

L= xlsread(fileName, sheetName , 'D1:D8761');

%%(2)System specifications

PV_Wp=2500; % the capacity of the PV array (Watt)

SOCmax= 1400; % battery capacity Wh/day

PV_eff=0.16; % efficiency of the PV module

V_B=12; % voltage of the used battery

Inv_RP=2500; %inverter rated power

DOD=0.8; %allowed depth of charge

Charge_eff=0.8; % charging eff

Alpha= .05; % alpha

Wire_eff= 0.98;

SOCmin=SOCmax*(1-DOD);

%%(3.1) Simulation of the SAPV system

P_Ratio=(PV_Wp *(G/1000))/Inv_RP;

Inv_eff=97.644-(P_Ratio.*1.995)- (0.445./P_Ratio); %5KW

E_PV= ((PV_Wp*(G/1000))-(Alpha*(T-25)))* Wire_eff.*Inv_eff;

E_net=E_PV-L;

SOCi=SOCmax;

SOCf=[];

Deff=[];

Dampf=[];

%%(3.2)

for i=1:length(E_net);

SOC= ED+SOCi;

if (SOC > SOCmax)

Dampi=SOC-SOCmax;

Defi=0;

SOCi=SOCmax;

%%(3.3)

elseif (SOC<SOCmin)

SOCi=SOCmin;

Defi=SOC-SOCmin;

Dampi=0;

%%(3.4)

else

SOCi=SOC;

Defi=0;

Dampi=0;

end

%%(3.5)

SOCf=[SOCf; SOCi];

Deff=[Deff; Defi];

Dampf=[Dampf; Dampi];

end

SOCf;

Deff;

Dampf;

SOC_per=SOCf./SOCmax;

LLP_calculated=abs(sum(Deff))/(sum (L));

Answer 1

[Cris LaPierre]

For the matrix subtraction operation to work, L must either be a scalar, or be the same size as E_PV.

The only way I can reproduce the error on that line is if I make L a different size. Check your raw data. Some of the data may be missing, or may be non-numeric.

G= rand(1,8761);
T= rand(1,8761);
L= rand(1,8760);  % <---- I have changed the size to reproduce the error ###################
%%(2)System specifications  
PV_Wp=2500;    % the capacity of the PV array (Watt)
SOCmax= 1400; % battery capacity Wh/day
PV_eff=0.16;  % efficiency of the PV module
V_B=12;    % voltage of the used battery
Inv_RP=2500;   %inverter rated power
DOD=0.8;     %allowed depth of charge
Charge_eff=0.8; % charging eff
Alpha= .05;          % alpha
Wire_eff= 0.98;
SOCmin=SOCmax*(1-DOD);
     %%(3.1) Simulation of the SAPV system
P_Ratio=(PV_Wp *(G/1000))/Inv_RP;
Inv_eff=97.644-(P_Ratio.*1.995)- (0.445./P_Ratio);   %5KW
E_PV= ((PV_Wp*(G/1000))-(Alpha*(T-25)))* Wire_eff.*Inv_eff;
E_net=E_PV-L;

Arrays have incompatible sizes for this operation.

[Stephen23]

"For the matrix subtraction operation to work, L must either be a scalar, or be the same size as E_PV."

Or have compatible sizes:

rand(3,1,2) - rand(3,5,1) % compatible sizes -> works

ans = 
ans(:,:,1) =

   -0.4983   -0.4474    0.1737    0.0522   -0.4380
   -0.1268   -0.1093    0.7476    0.0061    0.1320
   -0.0564   -0.1403   -0.0990   -0.2360   -0.3543


ans(:,:,2) =

   -0.7475   -0.6965   -0.0755   -0.1969   -0.6872
   -0.1137   -0.0962    0.7607    0.0193    0.1452
    0.5109    0.4270    0.4683    0.3313    0.2130

See:

https://www.mathworks.com/help/matlab/matlab_prog/compatible-array-sizes-for-basic-operations.html