Page 30 - Mathematical Models and Algorithms for Power System Optimization
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20   Chapter 2

            2.3.1 Notations

            See Table 2.2.


                                       Table 2.2 Mathematical notations
             Notation                                  Notation
             Name                Description            Name              Description
             i                   Unit number             NP            Set of power plant j
             j                Power plant number        N PLANT     Total number of power plants
             t                   Time period            N AREA          T number of areas
             N               Total number of units       N k              Set of area k
             T             Total number of time periods  P pg (t)  Generated output of pumped storage
                                                                         plants in time t
                                                                     MW, continuous variable
                           Cost of unit i in time period t
             C i (t)                                    P pp (t)  Pumping output of pumped storage
                                                                         plant in time t
                                                                       MW, discrete variable
                               Fixed cost of unit i
             F i                                         Y p (t)  Pumping step of pumped storage plant
                                                                            in time t
                                                                         Discrete variable
                                                                       Output limits of unit i
             X i (t)      Power output of unit i in time t,  P imax , P imin
                              continuous variable
             Y i (t)   Fixed power output of unit i, 0, 1 variable  P pg max ,  Generated output limits of pumped
                                                                          storage plant
                                                        P pg min
             PL(t)          Load in each time t,MW      P pp max  Upper limit of pumping output for
                                                                       pumped storage plant
                       Initial water quantity of pump storage  P pp unt  Unit capacity of pumping output for
             W 0
                                           3
                               plant, 10,000m                          pumped storage plant
                                                        SA j , SI j  Generated output limits of power plant j
                         Ending water quantity of pumped
             W 24
                                              3
                            storage plant, 10,000m
                                                       SAT j , SIT j  Planned energy limits of power plant j
                        Minimum water storage quantity of
             W min
                                                  3
                         pumped storage plant, 10,000m
                                                                  Generated output limits of area k
                                                       AA k , AI k
                        Maximum water storage quantity of
             W max
                                                  3
                         pumped storage plant, 10,000m
            2.3.2 Basic Expression of the Optimization Model
            A practical optimization problem after reorganization can be formed as the following standard
            mathematical programming model.
            Problem P:
                                                min fX, YÞ                                (2.1)
                                                     ð
                                               s:t: gX, YÞ ¼ 0                            (2.2)
                                                   ð
                                                hX, YÞ   0                                (2.3)
                                                  ð
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