دانلود Variable splitting applied to modelling of start-up costs in short term hydro generation scheduling

Abstract

In  this  paper a  mixed-integer hydro electric power model  for  short-term planning i s   discussed. The  purpose  of the model  is  to  represent the  generation characteristic of  the  hydro plants accurately. In the modelling  part the  paper focuses on two requests stated from power producers in an earlier study. First, it is  desirable  to  operate  on  points  with  good  efficiency. Second, start-ups and  shut-downs of  the  units  should  not be  carried out too  often, since  this  is  related to  a  cost.  The  problem  is  decomposed  into a subproblem for each hydro power  plant by relaxing the power  balance  equation  and  using  variable  splitting.  The advantage of  this relaxation is that we  can use network programming and dynamic programming methods, which have proved to work  well for power system planning issues. The relaxation used in this work  has, as far as we  know, not been applied in the field before. The master problem is solved by a subgradient technique. Finally, a  numerical example from  a  part of  the  Swedish power system illustrates the technique.