Torbjorn Magnusson. The Unit Commitment Problem - A Dual Approach. Licenciate Thesis TRITA-MAT-1991-44, Optimization and Systems Theory, Department of Mathematics, Royal Institute of Technology, Stockholm, Sweden, 1991.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....be on or off. New algorithms for the unit commitment problem that arises in short term production planning of district heating systems will be treated in detail in a forthcoming paper. For an overview of the thermal unit commitment problem that arises in short term power production planning, see [Mag91] and [Fel91] The economic dispatch problem minimizes the total production cost for a specific unit combination. When solving this problem we presuppose the knowledge of the heat power Q S from the storage. The heat power Q S is negative when pumping hot water into the storage. In Section 3 ....

....resulting start up cost is almost fl 1 k fl 2 k . This situation is called cold start. For a warm start, when the term (1 Gamma e fl 3 k T i Gamma1;k ) is close to zero, the cost is approximately fl 1 k . The start up cost equation (2) is standard and for example used by Magnusson [Mag91] Define Q i;S as the energy content of the heat storage at the end of time period i and the storage loss parameters q s and q s . The energy content for the next time step is defined by the recursive equation Q i 1;S = 1 Gamma q s )Q i;S Gamma ( Q i 1;S q s ) Delta i 1 : 3) There are ....

Torbjorn Magnusson. The Unit Commitment Problem - A Dual Approach. Licenciate Thesis TRITA-MAT-1991-44, Optimization and Systems Theory, Department of Mathematics, Royal Institute of Technology, Stockholm, Sweden, 1991.

....resulting start up cost is almost fl 1 k fl 2 k . This situation is called cold start. For a warm start, when the term (1 Gamma e fl 3 k T i Gamma1;k ) is close to zero, the cost is approximately fl 1 k . The start up cost equation (6) has been widely used, see for example Magnusson [Mag91]. The costs and constraints so far presented are common for all types of units. Now define c i;k (t f i;k ; t r i;k ; q i;k ; p i;k ; m i;k ; u i;k ) as the unit specific production cost and Omega i;k (t f i;k ; t r i;k ; q i;k ; p i;k ; m i;k ; u i;k ) as the unit specific constraints for ....

....constraints, the short term production planning problem (16) decomposes into Optimal Scheduling of Cogeneration Plants 7 q i;D t f i;D t r i;res HWC HWS DUM HEP CHP ELH Figure 2: The unit configuration. one separate problem for each single unit. This methodology was also used by Magnusson in [Mag91] for the solution of the closely related short term power production planning problem of an electricity grid. In (16) the unit coupling constraints are the heat demand constraints (14) the forward temperature constraints (15) the mass flow constraints (9) and the temperature constraints (10) and ....

Torbjorn Magnusson. The Unit Commitment Problem - A Dual Approach. Licentiat Thesis TRITA-MAT-1991-44, Optimization and Systems Theory, Department of Mathematics, Royal Institute of Technology, Stockholm, Sweden, 1991.

....decades numerous approaches for solving the unit commitment problem have been proposed. They are based on several optimization techniques such as heuristics and priority lists, dynamic programming, branch and bound methods, Benders decomposition, Lagrangian relaxation and combinations of them (cf. [1,6,8,9,11,15]) For a survey we refer to [14] where the authors come to the following conclusion: A clear consensus is presently tending toward the Lagrangian relaxation approach over other methodologies. Further applications of optimization techniques in power dispatch are considered in [4] The idea of ....

....linearly on the number of periods and assumed the average minimal up and down times are similar on the number of units. This behaviour is not observed for the whole procedure due to the uncertain number of BT and RFS iterations. Compared to subgradient type methods, which are used in [8, 9,15], an essential advantage of bundle trust methods is the reliable stopping criterion (without calculating primal feasible solutions in between) Different termination criteria in the literature (bounds for the relative duality gap, maximal number of iterations) complicate the comparison of test ....

Magnusson, T.: The Unit Commitment Problem: A Dual Approach. ITM Report No. 191:3, Goteborg, Sweden, 1991.

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