Reasearch On Optimal Configuration Of Micro-Grid With Wind-Solar-Battery-Diesel

With the development of economic society, people get more and more attention to the environmental issues, the problem of pollution and the depletion of fossil fuels have been emerged gradually, which makes people to pay attention to the renewable energy generation such as solar and wind, and apply to generate electricity increasingly. Constructing micro-grid systems in those remote areas which the conventional electricity grid can’t access to is a means to solve the problem of power supply. Since the micro-grid systems has no reserve capacity to support, random fluctuations of wind and illumination have influence on reliable operation of the system. Wind power and photo-voltaic power generation have characteristics of intermittent, rational allocation of micro-grid can meet the load demand for electricity, reduce the rate of loss of load and the costs of system, and provide the possibility to optimize the micro-grids.The article takes the micro-grid as a research subject, we propose a new way to optimize configuration of micro-grid. The main contents are as follows:Firstly, the structure of micro-grid is analyzed, the working principle of wind-solar power generation, batteries and diesel generators was discussed, establishing the model of distributed power.Secondly, the correlation between wind turbines output and photo-voltaic output was analyzed, due to the probability density curve of illumination intensity and wind speed is not fixed, in this paper, non-parametric estimation was used to calculate probability density of the wind and photo-voltaic generation, which is kernel density estimate. The joint probability distribution of wind and photo-voltaic output was calculated using Copula function according to marginal probability distribution obtained by marginal probability density.Again, based on the analysis of micro-grid system, an optimization function in which the lowest power generation cost work as optimization aim and the loss of load probability is regard as the constrained condition is established, and combine the union probability distribution of wind speed and sunshine with the loss of load probability as a constraint condition.Then, an optimal configuration model is established and improved harmony search algorithm is employed to obtain solution, and the selection of the algorithm parameter was considered, BW and PAR were improved, performance of the algorithm was ameliorated.Finally, under the platform of MATLAB, the procedures of modified harmony search algorithm were compiled, the optimization model was solved, and example is researched to prove the proposed method of optimal configuration. The first optimization of the model is established, due to considering the practical issues, the power of diesel generator is fixed and the other three parameters are optimized again. The results show that improving harmony search algorithm can speed up the solving convergence, and the proposed optimized configuration of wind and solar hybrid generation system can meet demand of load power supply and reduce construction costs.