| With the current shortage of energy,the development and utilization of wind energy is increasing and gradually developing towards offshore wind power generation.At the same time,offshore wind power generation is facing problems such as the mass and volume of the motor.However,the superconducting motor has the unique advantages of high current carrying capacity and large capacity,making the superconducting motor gradually widely used in offshore wind power.With the gradual deepening of the research of superconducting motors,in addition to studying the design of superconducting motors,optimize superconducting motors to reduce the amount of superconducting excitation coils and study the electrical characteristics of superconducting fan at the time of failure.Application of motor in actual engineering.Therefore,this article studies the design of the 10MW large-capacity superconducting wind turbine and the optimization of excitation winding.It analyzes the electrical characteristics of large-capacity superconducting motors in normal operation and different types of faults from the theoretical and software simulation.First of all,the rotating synchronous generator is selected in the design and the semi-superconducting motor with the superconducting material YBCO is used as the excitation winding.The stator and rotor dimensions and the excitation winding parameters of the 10MW superconducting wind turbine are designed according to the traditional motor design method.Then the width and thickness of the excitation winding are optimized by genetic algorithm,so as to reduce the amount of superconducting tape and improve the economy of superconducting tape.Secondly.the multiloop theory model is applied to the large-capacity superconducting wind turbine in this paper.On the basis of the multiloop theory,the voltage equation and the flux linkage equation of the superconducting wind turbine under normal conditions and the stator winding inter-turn short circuit are established.and the calculation formula of the inductance parameters of the superconducting motor is given,which provides theoretical support for the research of the superconducting wind turbine.Finally,the finite element simulation method and ANSYS Maxwell software are used to establish the model,and then the fault characteristics of large-capacity superconducting motor are simulated and analyzed.It includes the simulation analysis of three-phase short circuit and stator winding inter-turn short circuit fault:according to the critical current,it can be judged that the excitation coil will quench under the three-phase short circuit fault for a long time,and the operation of the high-temperature superconducting fan after the excitation winding quench is simulated.It is obtained that the efficiency of the motor is reduced due to the reduction of the excitation current and the increase of the air gap magnetic density harmonics after the quench:Simulate and analyze the fault characteristics of the fan during the inter-turn short circuit of stator winding.From the perspective of the air-gap magnetic field during the fault.it can be concluded that the change of the air-gap magnetic field in the inner side of the winding and the outer side of the winding during the inter-turn short circuit of the stator winding is opposite;From the analysis of fault phase voltage and current and its harmonics,it can be seen that the fault phase current decreases and the fault loop current increases sharply,and the third harmonic content increases with the increase of the number of short circuit turns;From the analysis of electromagnetic torque,it is found that the electromagnetic torque has double frequency component when the fault occurs. |
