Research On Sizing Of Storage Capacity In Distributed Generation And Storage Unit

The applications of distributed generation technology will be more widely use forced bydepletion of fossil energy and environmental protection. It brings a lot of new problems to thecurrent power system when connected to the grid. Particularly, when it comes to the principalcontradiction between randomness of distributed generation output and developmentrestrictions of distributed power. If with reasonable capacity and properly strategy connectedto grid system, the energy storage device not only make electricity equipment more efficientbut reduce the cost of power generation. In addition, it can smooth distributed power output,compensate for insufficient power supply load, improve the quality of the power supply.Consequently, it promotes the widely use of renewable energy generation technology.Therefore, research on the relationship between energy storage systems and distributedsystem with distributed generation has far-reaching significance in promoting the sustainabledevelopment of the power industry. In this paper, the study is based on in-depth analysis ofpower storage technology and effect of distributed generation. Do scientific and detailedexploration around the points about distributed generation supply reliability of distributionsystem, interaction between energy storage system and distributed generation supply, optimalallocation of energy storage systems. The main work was as follows:1．Establishing a mathematical model of wind, solar and storage generation united output.This paper is based on analysis of wind generation and solar generation output probabilitydensity function and energy storage output. Considering the coordination between energystorage device and wind generation or solar generation, the mathematical model ofcollaborative output between distributed generation and energy storage is established. Alsothe calculation method of probability in different energy storage state is deduced.2．An assessment method of distribution system reliability with distributed generationand storage unit is proposed on the basis of failure consequences mode analysis principle.This method use feeder partition to simplify distribution system structure and to judgedistributed generation supply range. The generation supply time of load region is calculatedbased on semi-invariant, Gram-Charlier series expansion and calculation of probability indifferent energy storage state. The reliability index of load reginal nodes is fixed. Exampleshows that the access of distributed generation significantly reduce the average interruptionduration of the load region and the addition of the energy storage further improve systemreliability.3．The multi-objective optimization algorithm of energy storage capacity is proposed. Energy storage capacity and rated power is defined as a decision variables. Themulti-objective model of reliability and storage economic index of distribution system withdistributed generation and storage units is established; Using the cooperative coevolutionarymulti-objective optimization method to efficiently solve the problem in distribution systemwith distributed generation and storage units and access to its pareto frontier; Assuming thatthe decision objective has engineering constraints limit, the program meet requirements to bescreened. So it verify the effectiveness and the engineering value of the above methods.This dissertation is supported by the high-tech industrialization key project inGuangdong (No.2010A010200005) and the Fundament Research Funds for the centeraluniversities (No.2012ZB0007).