Research On Importance Analysis Of Off- Grid Wind Power Generation System

With the rapid development of social economy and the continuous improvement of quality of life people, human demand for energy is growing, but the traditional energy such as coal, natural gas and oil is increasingly drying up, as a regular of renewable energy, it also brings increasingly serious environmental pollution problems in the process of development and utilization. Wind power, as a kind of green clean energy, has attracted much attention in recent years. Wind power is the first selection of wind energy, has the characteristics of renewable and almost no pollution. Total reserves of wind energy resources is very rich in our country, and because of the special geographic conditions such as China’s vast territory and complicated terrain, the independent operation of small wind power equipment can own good prospects and be important means in the areas without power grid. Off-grid type of small wind power generation also can save energy and improve the environment, which can relieve the tense situation of power supply, so the system reliability study with effective use of wind resources has important practical significance.Importance analysis is a concept in the theory of system reliability analysis, witch sizes the influence on the bottom events of the system to the system’s top event. Reliability analysis is a way to response system’s characteristics and get the information of the system about now or a period of future time by simulation model of the system, in order to guide system operation better and improve the defects in the design of the system. The importance measures model to be applied to system importance analysis is proposed in this study; Birnbaum importance model and Criticality importance model are simulated respectively. The small wind power system components is analyzed by the two methods to study the relationship between failure rate and connection ways, and further analysis between the two models on reliability are given. There are three main factors:1) the rate of system component; 2) connection way; 3) running time. Both criticality importance and Birnbaum importance applied in this paper can effectively analyze reliability of the system and calculate the component’s importance simply within a short time, which provides significance guiding for system design and maintenance. Compared with other onerous methods, both of them can make analysis on the system quickly and effectively, which is quantitative and qualitative, and can ensure the results accuracy and consistency. Failure rates, connection way, running time are main important factors for system and also the important objects for system upgrading.Run Weighting Parameters is put forward in this paper for improving the Importance model to be better applied to the system with complex structure and stronger relevance. To improve the practicability and pertinence of the models, a weighting parameter evaluation method is given for the off-grid type wind power generation system. The density distribution of wind speed and the power balance between supply and demand are two key factors for assessing Run Weighting Parameters. Finally, household type wind power generation system is applied to further verify the parameter evaluation method and the practical of importance analysis model. System maintenance guidance is given and the conclusion and prospect are put forward such as the future research directions, new potential challenges.