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Restrictions for equations

Posted: Tue Nov 21, 2017 4:44 pm
by NN6
Hey!

I have been modelling Load Shifting (LS) in a simple way which works so far:
LS_level(t,c)..
StorageLevel_LS(t,c)=e=StorageLevel_LS(t-1,c)+LS_in(t,c)-LS_out(t,c);
(The storage level is equal to the storage level the time period before plus what is stored from the system minus what is given back into the system)

LS(t,c)..
LS_in(t,c)=e=LS_out(t+1,c);
(The load can only be shifted for one time step, so what comes into the system in t has to go out in t+1)

StorageLevel_LS.up(t,c)=620;
StorageLevel_LS.lo(t,c)=0;
(the upper bound makes sure that no more than 620MW can be shifted per timestep)

Now I wanted to add another constraint, that no more 2615MW in total can be shifted during the time period I am analyzing. My idea was:
Cap_LS_level(t,c)..
Cap_LS(t,c)=e=Cap_LS(t-1,c)-LS_in(t,c);
Cap_LS.up(t,c)=2615;
Cap_LS.lo(t,c)=0;

Unfortunately this does not seem to work as load shifting in the results is not used at all anymore. I tried setting the Cap_LS.up(t,c)=1000000 to see if the upper bound was preventing it from being used but it seems to be the Cap_LS_level equation for some reason.

I would be very thankful for any tips or solutions to implement this constraint!!