Hydrothermal Coordination With Unit Commitment

Hydrothermal coordination (HTC) with unit commitment, which has prominent economic benefit, is an important research object in power system. But till now, we don't find a perfect method to solve it, because this problem is a large, dynamic, non-convex mixed integer problem.Semidefinite programming (SDP) is an active research in math programming, and is a convex programming method with polynomial solution time. In order to get a method for solving Hydrothermal coordination by SDP, this paper pay more attention to HTC model, SDP technique, interior point method and its technique.The HTC problem can be formulated as a convex optimization problem without explicitly stating the integer value requirements for the thermal plants discrete variables. Thus it is possible to replace the non-convex integer-value constraints by convex quadratic constraints, and then use SDP. In this paper, we research into {0,1}-Economic dispatch(ED) between thermal plants, Unit commitment of power system and Hydrothermal coordination with unit commitment. For the {0,1 }-ED problem, we test its validity by nine systems. The numerical simulation of six UC problems shows: SDP can efficiently process the ramp rate constraint; has smaller computation time and be applicable for large scale UC; the more important is that SDP's results are better than other six methods such as GA. For the HTC, we have 3 test systems, its solution shows SDP can efficiently solve the HTC problem, where Hydro plants can effect the "daily crossover".