This paper presents Security Constraint Unit Commitment (SCUC) backup plan considering single contingency. The proposed method leads solution to obtain optimal units and reserve schedule. In equivalent linear expression of the problem, shedding costs are used to avoid divergence and resolve congestion problem. Obtained load shedding in contingency case are utilized to achieve an optimal reserve requirements. Mixed Integer Linear Programming (MILP) is employed to minimize the total energy dispatch cost in 24 hours of a day. Numerical results show the proposed joint auction model can clear energy and reserve market while system violation and unit outage are considered.

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