Fault-Tolerant Control Of Double PWM Converter In Variable Speed Constant Frequency Wind Power Generation System

Energy is the development of society to today's major hot strategic issues,is the national economy,the national productive forces continue to develop the lifeblood.So energy-saving emission reduction and new energy technology development has become an important policy of China's economic life.Wind energy as a natural existence of the endless renewable energy,it has a pollution-free,widely distributed and so on.Clean and sustainable development of new energy power generation technology,especially the most large-scale and commercial development prospects of wind power has become a global energy system research hotspot.Because of the limitations of island wind power generation technology,grid-connected wind power generation is more in line with the operation of large power grid.The doubly-fed wind turbine can be driven to maintain maximum wind energy according to the wind conditions and as part of the power converter(30%),This main feature is less expensive than other fans to make it the world's most widely used wind turbines.In this paper,the most typical doubly-fed wind generator(DFIG)is selected as the research object,The operation principle of DFIG and its dual PWM converter is analyzed.And this article mainly discusses the following aspects:1.Firstly introduces the control effect of the double-PWM converter in the DFIG,and expatiates on the DFIG and its dual-PWM conversion in the three-phase stationary abc coordinate system and the synchronous rotating dq coordinate system.Then the decoupling scheme is given based on the mathematical model of the double PWM converter after coordinate transformation,and the vector control technology of the network side PWM converter and the machine side converter is studied.Policy research.Finally,the policy is given.2.For the MPC can better deal with dual PWM converter in a large number of physical constraints of the situation.The Application of MPC in Dual PWM Converter.However,the dual-PWM converter system,although it has the characteristics of non-linearity after coordinate transformation,discusses the processing of linear processing.For MPC needs a large number of real-time computing processing,it is difficult to apply in the electromechanical system.This paper introduces the Explict-MPC and discusses the application of EMPC in the network side PWM converter unit,and finally verifies it by simulation.3.The influence of the power grid imbalance on the DFIG system is introduced.The power mathematical model of the grid side converter under the asymmetric fault of the grid is deduced,and then the control objectives of the grid side PWM converter are designed.Order double dq coordinate axis,double PI control strategy.Also the method of extracting the respective components based on the notch filter and the time delay method is designed for the operation of the positive and negative sequence components in real time.The advantages and disadvantages of each method are briefly described.Finally,the above algorithm Simulation verification.