Research On Theory And Key Technology Of Double Rotor Permanent Magnet Wind Turbine

As one kind of emerging industry, wind power technology has been booming in recent years, and it’s research wave has been set off over the world. As one of the new green energy, the use of wind energy has a very bright future. The purpose of wind power technology is to maximally change the instability wind energy into electricity which can be effectively used by human beings, and to improve the efficiency of wind energy utilization. This paper proposes a new type of wind turbine—dual-rotor permanent magnet wind power generator which constitutes wind power system, and also analysis and research the key technologies such as running and grid-connected of the system.By analyzing the wind energy conversion principle this paper proposes the dual-rotor structure, and uses permanent magnet to achieve excitation. The front and rear fan rotations drive the internal and external rotors of the turbine, as to achieve the conversion of wind energy into electrical energy. Give reasonable analysis of the basic structure of the motor, the stator winding manner and the form of permanent magnets. By comparing with ordinary permanent magnet generators about running mechanism, clear that the new motor has obvious advantages in terms of improving the utilization of wind energy. It can reduce start up wind speed of wind turbine, and effectively widening the range of wind speeds, so can help generators running securely and smoothly. In order to facilitate further research and analysis, this paper builds a mathematical model of the wind turbine.In order to improve the utilization of wind energy, we use the maximum power point tracking control to make the wind turbine always running at maximum power point. By analyzing the operation characteristics of the wind turbine under different wind speed can get the optimum power curve, so as to propose tracking strategy according to this curve. After comparing a variety of control strategies we choose the appropriate algorithm of the new generator proposed, and introduce the fuzzy controller to make the maximum power point tracking more quickly and efficiently. Due to the double wind wheel structure, we study the control strategy when the power of the system higher than the rated power, and give distinguish methods of control conditions to achieve complete control of the wind turbine in a variety of wind speed. This paper also study the grid-connected control method of wind power system,gives system topology structure, elaborates the principle of variable-speed operation of the system, and ensure the structure and function of each part. Indirect and direct current control methods are respectively given through a mathematical model of the inverter, which have their own advantages. Direct current control enables the output active and reactive power independently controlled, so is more conducive to the realize the stability of grid-connected.Finally, we use Matlab/Simulink simulation the control system, so as to verify the feasibility and effectiveness of the control method proposed in this paper.