| The problems of environmental pollution and energy shortage have seriously restricted the sustainable development of human economy and society.It has become the consensus of the whole society to solve the problem of energy supply by developing new energy generation.With the increasing proportion of renewable energy,the dispatching mode of power system is also changing in order to adapt to the power market policy and environment.At present,in view of the impartiality of power system dispatching problem,electric power departments often adopt the impartiality and openness of power dispatching model,which can realize that the power completion schedule of each power plant is roughly the same,so as to treat each market subject fairly and protect the interests of power generation enterprises.However,this dispatching mode seriously restricts the optimization space of power system operation economy,and because of the characteristics of new energy output,the impartiality and openness of power dispatching model is not applicable to the current large scale wind-solar connected system.Therefore,under the condition of ensuring the economy of system operation,how to realize the impartiality of power output of system with high proportion renewable energy is a subject of important significance.The main research contents of this thesis are as follows:(1)Thesis analyzes the output characteristics of the group of wind power plants and photovoltaic power stations,and establishes the corresponding mathematical model for the large-scale wind-solar grid system in Jiuquan,Gansu.The pumped storage power station is considered as an excellent regulating power source to relieve the peak regulation pressure of thermal power units,so thesis analyzes the basic operation principle and peak regulation characteristics of the pumped storage power station and proposes the combined operation strategy of wind-photovoltaic-pumped storage,which provides theoretical support for the subsequent optimization of wind-photovoltaic-pumped storage.(2)In order to ensure the reasonable rights and interests of each new energy station and the impartiality of dispatching plan among new energy stations,thesis proposes a impartial dispatching method based on fuzzy comprehensive ranking so that new energy stations and power grid can realize the coordinated operation in the real sense.First of all,based on the analysis of the impartiality and openness of power dispatching model of the traditional power grid and the power system with new energy,thesis establishes the fuzzy comprehensive ranking evaluation system.Then,the indicators at all levels in the system are quantified,and the priority ranking of the new energy stations is carried out through the grey relational degree analysis and entropy weight method,so as to reasonably allocate the power of each station and guarantee the impartiality of the dispatching plan.(3)Aiming at the problems of how to ensure the operation economy of large-scale wind-solar connected system and achieve impartial dispatching among new energy power stations,thesis proposes a two-stage optimal dispatching model of wind-photovoltaic-pumped storage combined system considering economic optimality and impartial dispatching.Through the calculation of comprehensive ranking priority,the day-ahead scheduling plan of each new energy station is allocated impartially,and the output of each station is optimized according to the principle of maximizing the consumption of new energy.Finally,a concrete example is given to show that:(1)The scheduling method based on fuzzy comprehensive ranking not only ensures the economy of system operation,but also takes into account the impartiality of power output of new energy stations and makes full use of the absorption space.(2)The medium and long term dispatching based on this method can significantly improve the power balance of each station and realize the Medium and long term impartiality of dispatching. |
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