Calculate the total average daily load

Hi guys,

I want to calculate the total average daily load consumption for a microgrid. I have the hourly load data and I tried by doing like this:

%% designing the minigrid according to IEEE standard:
% convert the load data  from watthours to Amperehours:

%mean_load_Wh=mean(Dataclean_interpolated.InverterEnergy)
Power_Ah=Dataclean_interpolated.InverterEnergy./Dataclean_interpolated.BatteryVoltage;

% calculate the total average daily load:



mean_load=retime(Power_Ah,'daily','mean');

K_p=0.1;% Parasitic losses

D=6; % 10.5 or 6 or 3 ( days of autonomy) depending on different IEEE standards)

C_un=D.*(mean_load.*(1+K_p))

%the adjusted battery capacity:
%C_ad=(C_un X K_t X K_m)/DOD
K_t=1.048; % temp.correction factor
K_m= 1.25;% Design margin
DOD=0.50;% maximum daily depth of discharge

C_ad=(C_un * K_t * K_m)/(DOD)% final battery capacity in Ah

but I get this message:

Undefined function 'retime' for input arguments of type 'double'.

Error in test_func (line 98)
mean_load=retime(Power_Ah,'daily','mean');

I have very basic knowlage in matlab and have learned already a lot from this group and I appreciate all your feedback and help!

Thanks in advance!

Answer 1

[Steven Lord]

The retime function requires the first input to be a timetable array. From this line of code:

Power_Ah=Dataclean_interpolated.InverterEnergy./Dataclean_interpolated.BatteryVoltage;

I suspect Dataclean_interpolated is your timetable. If so I'd store Power_Ah as a new variable in that timetable then call retime on the timetable.

Dataclean_interpolated.Power_Ah = Dataclean_interpolated.InverterEnergy./Dataclean_interpolated.BatteryVoltage;

Alternately you could call groupsummary on your data with the times from your timetable as the groupvars input. See the "Group Operations with Vector Data" example on the groupsummary documentation page I linked earlier for an example you could adapt to your problem.

[Abm]

Thank you so much Steven! I stored the Power_Ah in the time table and the problem is fixed :) I wanted to learn how to use the groupsummary method also but it doesnt work to calculate the total daily load, if you have time could you suggest how to write the line code for it? if not, I am satisfied with the alternative solution and thank you again!

Best regards!