Comprehensive algorithm for hydrothermal co-ordination

Comprehensive algorithm for hydrothermal co-ordination

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The authors present a comprehensive hydrothermal co-ordination algorithm where a new Lagrangian relaxation based hydrothermal co-ordination algorithm is integrated into an expert system. In this algorithm, the problem is decomposed into the scheduling of individual units by relaxing the demand and reserve requirements using Lagrangian multipliers. Dynamic programming is used for solving the thermal subproblems without discretising generation levels. Instead of solving the hydro subproblems independently as in the standard Lagrangian relaxation approach, hydrothermal scheduling is used to solve the output levels of hydro units. Hydrothermal scheduling uses the commitment status of thermal units obtained from the solutions of the thermal subproblems. The expert system takes care of constraints that are difficult or impractical for implementation in the Lagrangian relaxation based hydrothermal co-ordination algorithm, such as cycling of gas and steam turbine units, etc. It is also applied to check the feasibility of the solution. Extensive constraints such as power balance, spinning reserve, minimum up/down time, must run, capacity limits, ramp rate and hydro constraints are considered. Accurate transmission losses are incorporated. Nonlinear cost function is used, and the hydrothermal scheduling is implemented using a fast and efficient algorithm. Numerical results based on a practical utility data show that this new approach provides feasible schedules within a reasonable time.


    1. 1)
      • A. Aoki , T. Satoh , M. Itoh , T. Ichimori , K. Masegi . Unit commitment in a large scale power system includingfuel constrained thermal and pumped storage hydro. IEEE Trans. Power Syst. , 4 , 1077 - 1084
    2. 2)
      • S.K. Tong , S.M. Shahidehpour . An innovative approach to generation scheduling in large-scale hydro-thermalpower systems with fuel constrained units. IEEE Trans. Power Syst. , 2 , 665 - 673
    3. 3)
      • H. Yan , P.B. Luh , X. Guan , P.M. Rogan . Scheduling of hydrothermal power systems. IEEE Trans. Power Syst. , 3 , 1358 - 1365
    4. 4)
      • X. Guan , P.B. Luh , H. Yan , J.A. Amalfi . An optimization-based method for unit commitment. Int. J. Elect. Power Energy Syst. , 1 , 9 - 17
    5. 5)
      • T. Sakaguchi , H. Tanaka , K. Uenishi , T. Gotoh , Y. Sekine . Prospects of expert systems in powersystem operation. Int. J. Elect. Power Energy Syst. , 2 , 71 - 82
    6. 6)
      • S. Mokhtari , J. Singh , B. Wollenberg . A unit commitment expert system. IEEE Trans. Power Syst. , 1 , 272 - 277
    7. 7)
      • Md.S. Salam , A.R. Hamdan , K.M. Nor . Integrating an expert system into athermal unit commitment algorithm. IEE Proc. C, Gener. Transm. and Distrib. , 6 , 553 - 559
    8. 8)
      • Salam, Md.S., Nor, K.M., Hamdan, A.R.: `An experience in developing anexpert system for scheduling problem in electric power system', 11th international conference on Applications of artificialintelligence in engineering - AIENG96, 1996, Tampa, Florida, USA, p. 647–662.
    9. 9)
      • A.H.A. Rashid , K.M. Nor . An efficient method for optimal scheduling of fixedhead hydro and thermal plants. IEEE Trans. Power Syst. , 2 , 632 - 636
    10. 10)
      • O.I. Elgerd . (1971) Electrical energy systems theory: An introduction.
    11. 11)
      • ‘SICStus Prolog Release 2.1’ (Swedish Instituteof ComputerScience, Sweden, October 1991).

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