Research On Wind Turbine Emulation System With Flexible Transmission Characteristics

Due to the existence of torsion deformation,high power,long shaft wind turbine in the actual operation process,the transmission chain will show the characteristics of flexible transmission.In order to simplify the difficulty of emulation,the traditional wind turbine emulation system often ignores the flexibility of wind turbine,but it will reduce the accuracy of wind turbine emulation.In order to solve this problem,this paper presents a simulation method of flexible transmission characteristics of high-power wind turbine based on torque closed-loop control,which can accurately simulate the flexible characteristics of the actual wind turbine transmission part through the permanent magnet synchronous motor(PMSM).First of all,the wind speed model,wind turbine model and flexible characteristic drive chain model of the actual wind turbine are established,scaling wind turbine parameters to a range where the emulation system can be simulated.Then the mathematical models of PMSM in three phase stationary coordinate system,two phase stationary coordinate system(?-? coordinate system)and two phase synchronous rotating coordinate system(d-q coordinate system)are established.The space vector pulse width modulation(SVPWM)technology and the vector control strategy of PMSM based on SVPWM are introduced.The emulation model of PMSM under Matlab/Simulink environment is established.Then the flexible drive chain of high power wind turbine is reproduced by torque closed loop control.For the sudden change of wind speed and load torque,and,the equivalent high-speed shaft torque of the wind turbine is taken as the given torque the emulation system can well reproduce the flexible oscillation characteristics of the actual wind turbine under the condition of the sudden change of wind speed and the sudden change of the load torque.The amplitudes of both oscillations are in agreement with each other.In addition,the method of electromechanical system analogy is used to analyze the range of emulation system,which is verified in the simulation.On the basis of theoretical analysis,the design methods of hardware system,such as power circuit,conditioning circuit,power supply circuit and control system based on RT-LAB,are given in this paper,which provide the basis for experimental verification.The experimental results are in good agreement with the simulation results.Therefore,the simulation system has high reliability and flexibility,and can be used to simulate wind turbine in laboratory.