Solution to short term hydrothermal scheduling problem for a power system area including limited energy supply thermal units by using modified subgradient algorithm based on feasible values

摘要

In this paper, the modified subgradient algorithm based on feasible values (F-MSG) is applied to a short term hydrothermal coordination problem for a power system including limited energy supply thermal units. In the proposed method, all the constraints such as units' power generation limits, transmission line capacities, bus voltage magnitude limits, hydraulic units' minimum and maximum reservoir volume limits and hydraulic units' starting and final reservoir water volumes are added into the optimization model. Actual transmission losses are inserted into the optimization model as equality constraints via load flow equations. It is also assumed that limited energy supply thermal units are fueled under take-or-pay agreement. The proposed method is tested on 16 bus test system which includes three normal thermal plants, two limited energy supply thermal plants and four serial-parallel hydraulically coupled hydro plants and better results are obtained in terms of optimal fuel cost values.