Dear all,
I was recently faced with a system that experiences a negative lambda. Upon
further analysis, this happens when minimum generation exceeds load, which is
typical in a Winter season. So, i have tackled it by using the unit
de-commitment algorithm provided by matpower. However, i was faced with an
expensive computational time that takes almost 30 minutes to solve one instance
of DCOPF. So, i have several ways to resolve the issue and i am wondering about
the possibility of implementing these possibilities into the unit de-commitment
scheme to save some computational time even if that means a less optimal
solution for my case. The following are the approaches:
1) De-commit units and check against the sum of the minimum of generators till
the issue is resolved without running the DCOPF each time.2) Turn units
sequentially using a priority list without looking into different combinations.
I am not sure how matpower does that but i suspect that matpower tries
different combinations of generators that are turned ON and OFF and saves only
the cheapest objective function (the minimum total cost). If so, this is
computationally expensive, especially for large systems and can create
computational infeasibility.
So, what is the case file that performs the unit de-commitment. Is it the
uopf.m? If so, i need someone to explain to me the algorithm because some
commands that are used for the de-commitment decision are not familiar to me.
Also, I appreciate any feedback in regard to the subject issue. Thanks for your
cooperation in advance and take care.
Kindly,
