Abstract:

With the parallel development of  distributed generation technology and  large power grid technology, a great amount of renewable energy generation was introduced to the electrical power grid. Under this circumstance, a unit commitment model was established by considering the constraints of transmission safety using AC(alternating current) power flow.  This model also involved reactive and voltage constraints, as well as safe operation limits of generators. According to the Benders decomposition, the model was decomposed into a master problem and a sub-problem. The master problem could solve the unit commitment without AC constraints, and then the sub-problem could check the AC constraints according to the result of the master problem. Benders cuts might develop from the sub problem, and the cuts would form additional associated constraints, which could connect the master problem and the sub problem. Simulation results of modified IEEE-14 buses case proved that the proposed method could effectively solve unit commitment problems with constraints of AC power flow.

Key words: power system, unit commitment, AC power flow constraints, Benders decomposition, safe operation limits of generato