Research On The Power Control Technology For Wind Turbine With Hydro-mechanical Transmission

With the reduction of fossil fuel and the environmental pollution caused by the burning of fossil fuel, the world pay more and more attention to the development and utilization of wind power and other renewable energy. Wind power is the most mature technology today and most large-scale development prospect of renewable energy sources. New installed capacity of wind turbine in the world continues to rise. Maintenance costs of wind power equipment, operational reliability and life issues also will be a growing concern, especially the presence of the traditional wind turbine gear box failure rate, converter technical complexity and harmonic interference and other issues. In this paper, wind turbine based on the hydro-mechanical hybrid transmission will not be same inefficiency as hydraulic transmission. Through the rational allocation of system parameters, wind turbine can transmit most of the power by mechanical transmission and a small number of power by the hydraulic transmission. Hybrid transmission mitigate the impact load. Then power converge and supply excited synchronous generator. This generator does not produce nearly harmonic interference. The wind turbine does not rely on traditional converter to control generator electromagnetic torque, but by controlling the variable displacement pump to control the rotor speed to capture the maximum power. Also, The wind turbine can adjust the generator speed to meet the grid requirements.The paper is divided into five chapters to introduce the research on wind turbine with hydro-mechanical hybrid transmission power control technology. The main contents of the five chapters can be summarized as follows:The first chapter introduces the research background, domestic wind power development and technology status. The research content and research significance are proposed.In the second chapter, some types of the hydro-mechanical hybrid transmission are demonstrated. The best type of hydro-mechanical hybrid transmission which suitable for wind turbine is proposed. Then the theoretical analysis of the speed, power, efficiency characteristics of the transmission system is put forward. The synchronous speed control methods based on this transmission mode and maximum power capture methods below the rated wind speed are proposed.In the third chapter, a dynamic model of the wind turbine is created, including wind speed, wind wheel, hybrid transmission, excited synchronous generator and power grid model. Hydro-mechanical hybrid transmission model is established to verify its speed, power and efficiency characteristics in AMESim. The parameters of main components in the wind turbine are calculated. Then a cosimulation of AMESim and MATLAB/simulink is conducted on a 1.5MW grid wind turbine.The simulation results validate the feasibility of the transmission system and demonstrate that the novel wind power generation system is characterized by simple Variable Speed Constant Frequency (VSCF) control algorithm, low load impact, high transmission efficiency and grid-friendliness.In the fourth chapter, the simulation test equipment for 30kW wind turbine with hydro-mechanical hybrid transmission is designed, including hardware selection, PLC control system design, test system design. The experiments show that the wind wheel simulation device can quickly track the input speed, torque output accurately simulate the wind wheel. The data display, record in test system are well. PC communicates with the PLC and instruments properly.In the fifth chapter, the paper’s research work and outcomes are generalized, and the directions for further working are also pointed out.