Research On Short-term Optimal Operation Of Hydrothermal System In Guizhou Power Grid

As the fast growing of thermal power systems and intensive exploitation of hydropower resources in large rivers, a number of hybrid power grids contains massive thermal and hydraulic power plants has been formed. More complicated structure of hydropower system and energy saving policy that is being carried out in thermal system brought new challenges to the practical operation of power girds. Short-term scheduling has always been a difficult research spot for its intensive time coupled relations between power elements. At the same time, as a prerequisites for load distribution optimization, maintenance scheduling also faces many new challenges. This paper take Guizhou Power Grid as background, researched short-term optimized scheduling of hydrothermal hybrid power system based of which peak load is regulated by hydropower resources, then discussed maintenance optimization method of generating equipment and designed an visualization system for maintenance scheduling, works are detailed as follows:(1)Formulated short-term scheduling model for peak energy maximization by practical constrains for cascade hydropower plants, of which day as a cycle and15min as a single time period. In the model, lag time of flow from up streams to down streams and power grid division constrains are taken into account. In the solution, firstly fitting hydropower plants into virtual units, then take POA method as solution to solve the model. In order to decrease iterative times of POA, successive load cutting method is employed to get better initial curves. At last, necessary modification to the model result are made by considering power grid divisions constrains. The model has been proved effective through practical application of10cascade hydropower plants on Wu river.(2)Proposed short-term scheduling model for thermal units with a day for a cycle, brought in constrains like minimum last periods and climbing capacity of generators. Detailed the application of equal incremental principle and units-combination method in thermal-units daily scheduling. Then described the problem that has been discovered in energy saving scheduling practice, and further propose the method of equal incremental principle based on units’capacity. The two methods are applied in thermal system of Guizhou power grid, of which results indicate that the proposed method is useful and of practical value for actual scheduling works. (3)Formulated optimal maintenance scheduling model based on reliability, and designed an visualized system for maintenance scheduling. Association between electrical equipment is revealed clearly through visualization technology, which can widely decrease the possibility of making mistakes during the check of maintenance schedule.Finally, summarized the work that has done and discussed potential issues that can be further studied in private opinion.