sddp model john attached copy sddp methodology manual written developers model developed mario pereira proprietor psri power systems research inc rio de janeiro web site www psr inc com find information company contact details mario staff speak english phone calls possible development sddp originally done world bank contract compare benefits new generation transmission system interconnections central america since found much wider application code runs pc licensed number consultants power companies etc ecnz wellington new zealand purchased copy around 1994 model works weekly monthly time steps time horizon 1 10 years mid long range planning hydro thermal power systems represents loads period one five load blocks chronological model type model handle thermal plant ramp rates similar chronological system constraints sure important would optimization phase model takes account hydrological uncertainty using form stochastic dynamic programming sampling phase sets function water value large reservoir system simulation phase uses number hydrological outcomes collect statistics system would operate water values used short term optimization mode sddp detailed short term optimization model constraints found hydro systems modelled many transmission constraints modelled dc load flow option used determine bus nodal prices visual basic user interface provided reads writes text files like know sddp could call houston tel 001 713 345 8539 tom halliburton