| Wind power generation is the most advanced and large-scale developed way to use renewable energy in the world with continuously rapid development. At present, the wind turbines in wind farm are mainly divided into two kinds:horizontal axis wind turbine and vertical axis wind turbine. Vertical axis wind turbine has won attentions by its simple structure without yaw devices. Compared with horizontal axis wind turbine, the development of vertical axis wind turbine is delayed in aerodynamics, structure mechanics and turbine commercial development. In recent years, researchers around the world have contributed to the technology of vertical axis wind turbine power generation, optimizing and improving its wheel structure and energy utilization. Generally, vertical axis wind turbine has good prospect.In this paper, vertical axis wind turbine is treated as research object and wind turbine hydraulic transmission technology is researched. By its good controllability and impact resistance, wind turbine hydraulic transmission technology, which replaces the mechanical transmission connecting wind turbine with generator, has been a heated research area in recent years. The research methods in this paper include theoretical research, mathematical simulation, lab experiment and field experiment. The main work of the paper includes four parts:performance analysis and design of vertical wind wheel, characteristic analysis and design of hydraulic transmission system, system simulation and research of wind unit and experiment research and verification of wind unit.Firstly vertical axis wind turbine is regarded as research object in this paper. The aerodynamic characteristics of vertical axis wind turbine is analyzed through the study of fluid mechanics and aerodynamics. The mathematical model of predicting wheel performance output using the modified two-way multiple stream tube model has been built, and the model has iterative calculation and simulation analysis by Matlab programming.Through the study of this part, the different parameters of wind turbine output performance, including the dimensions of the wind wheel diameter, height, airfoil shape, chord length, wind wheel speed etc. can be analyzed. And the optimal design for the vertical axis wind wheel has been done, which on the base of simulation analysis model for vertical axis wind turbine performance. The optimal design regards the parameters of wind turbine output performance as the constraint conditions and the maximum power of wind turbine as the optimization target.Based on the study of vertical axis wind wheel, the hydraulic transmission wind power generation technology has also been studied in this paper. The technology is currently emerging as a novel research direction, the connection between the wind wheel and generator alternates from rigid pattern to flexible hydraulic transmission, absorbing unsteady load effect results from wind wheel transmission, prolonging the service life of the generator. In the analysis and design of hydraulic transmission system characteristics, the basic characteristics of the hydraulic transmission is studied firstly, hydraulic transmission system scheme design is made combined with the actual operation of the wind turbine. And AMESim is used to establish the hydraulic transmission system modeling and simulation by Simulink-AMESim co-simulation technology to establish the whole simulation model, including natural wind speed, wind wheel, hydraulic transmission system, power generation and load system etc. The model covers the mutual influence of each subsystem. The output characteristics can be systematically studied on the whole vertical axis wind turbine machine, analysis in response to a case of natural wind under the influence of wind wheel, hydraulic transmission system, the generator and load of each subsystem can be made.Based on early theoretical study and simulation analysis, experiments in the laboratory and late field experiments had been implemented on the hydraulic transmission vertical axis wind turbine in this paper. In the special capital projects funded by the marine renewable energy, a test unit was built in the laboratory, in order to test response characteristics of the rear transmission system using variable frequency motor and generator to simulate wind turbine mechanical energy output. In this paper, a reasonable and reliable control system was designed to guarantee analog output of the motor and generator in accordance with the practical situation. Experiment in the laboratory is an important way to study wind machine, rapidly controllable performance test of the transmission system could be carried out by this method. In addition to research experiment, a field experimental study of vertical axis wind turbine had also been carried out in the paper. Field experimental study not only test the machine comprising the wind wheel in the natural environment, but also it can more accurately obtain the actual performance of the unit, so the test data are also more reference value. Experimental study on the collection of a large number of experimental data, researches had been done on basic transmission characteristics of the hydraulic transmission system, response of the unit in the impact load and fluctuating load, response of the unit under actual wind speed, output characteristics of the displacement control of generator power. The experiments has provided valuable data support for the theoretical research and the subsequent unit optimal design.In this paper, the author researched vertical axis wind turbine power generation technology and hydraulic transmission wind turbine, built corresponding simulation model and performed lots of indoor experiments and field experiments. By theoretical research and experiment verification, this paper has many conclusions with reference value for other researchers in this area and the development of vertical axis wind turbine. |
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