Research On Comprehensive Evaluation Of Distributed Generation Grid-Connected

Under the new situation of power reform and green power development, China is facing the dual pressures of economic growth and resource constraints. Then, developing low carbon power, improving the energy supply pattern and pursuing sustainable energy development has become the most important energy development strategy for China. The notion of low carbon development is highlighted and a modern energy system is proposed in the 12th Five-Year Plan in China. In view of these, distributed generation (DG), the characteristic of flexible, efficient, economic and environmentally friendly, has been attracting many countries across the world. DG will be the future direction of electric power industry. However, with the continuously development of DG, it will have significant effects on power system. For instance, load forecasting, planning and operation of power system will face uncertainties. Therefore, it is necessary to assess the impact of distributed generation on power grid operation for effectively avoiding the risks existing in the process of grid-connected.The effect of distributed generation grid-connected on power grid is discussed in this paper. Firstly, the overview of distributed generation, the current status and related policies of distributed generation power connecting into grid and are analyzed in this paper. Secondly, the impact of distributed generation connected into grid on power grid companies in the aspects of economical benefit, security and reliability is analyzed qualitatively. Thirdly, through the analysis of impacting factors from distributed generation connecting into grid on grid companies, comprehensive evaluation indicator system of DG connecting into grid covering economical benefit, security and reliability is built combining with indicators principles in this paper. Fourthly, combination weights of indicators from the methods of Delphi, Coefficient of variation, grey correlation are calculated. What is more, performance optimization model is constructed based on the maximum entropy principle and the maximum deviation square so as to sequence the three plans of DG connecting into grid. What is more, the comprehensive evaluation model under the combination weights method is verified in this paper. In addition, a case study is taken for verifying the different utilities from DG connecting into grid in different positions. And several DG resources connecting into grid simultaneously are better than single DG resource. Finally, guarantee mechanisms for promoting DG connecting into grid from the perspectives of technical, policies and management. It is hoped that the study of this paper can provide theoretical references for further absorbing DG resources.