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Discrete Optimization for Reactive Power Planning 213

                   3rd stage: Generate new exploration points with GA, that is, reset the solution and variable
                   bounds to the problem. When the exploration points have been over M (generally 10–50,
                   given based on the calculation scale and experience), it is believed that the problem has no
                   integer-feasible solution stop exploring; otherwise re-enter the 2nd stage.

               Improvement procedure for new integer solutions:

               Similar to the main process, such procedure is equivalent to the steps to produce the new
               exploration groups in GA:

               (1) Set the new bounds of the problem.
               (2) Generate new problems.
               (3) Resolve the problem, and if the objective is improvable, enter the next step,
                    otherwise stop.
               (4) To generate new solutions using GA and judge whether they satisfy the stopping criterion,
                    that is, when exploration points >M (generally 10–50, given based on the calculation
                    scale and experience), stop exploring, otherwise reenter Step (2). Fig. 6.12 shows the
                    improvement procedure of GA-based integer solutions.




                                                 Start

                                            Set the new adjusted
                                                bounds


                                             Solve the current
                                             exploration points

                                            Whether the objective  No  Abandon the current
                                             function improved?     exploration points
                                                Yes
                                            GA operation under
                                              expert rules


                                            Form new exploration
                                                 points

                                    No
                                              Whether satisfying
                                               stop criterion?
                                               Yes

                                                 Stop

                                                     Fig. 6.12

                                      Improvement of GA-based integer solution.
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