Control Study And FPGA Simulation Of Doubly-fed Induction Generator And Converter

With The increasing share of the wind power in the power grid,a stable operation of the grid connected wind turbine generator system is important for the grid.Variable speed constant frequency wind power technology,especially the doubly-fed wind power technology,has received extensive attention with its unique advantages.In this paper,the operation and control strategy of DFIG and its excitation converter have been analyzed,and then the real-time simulation has been realized based on PXI-FPGA platform.Firstly,the operation principle of DFIG and its excitation converter have been analyzed,and the interaction between DFIG and converter,the grid side converter and the rotor side converter have been analyzed.The model and control study based on two-way flow energy has been made.On this basis,the Lab VIEW program of the model and control system of the DFIG and the converter has been established.Using simulation technology in study of actual object by overcomes the defects of high cost and long experiment cycle in physical experiment research.Real-time performance is hard to realize with common simulation platform in the simulation of power,electronic components due to the high request for the calculation step and the accuracy.Starting with the idea that hardware has good data processing speed and stable operation performance,the program of the dual-PWM converter has been repeatedly modified and debugged through the Lab VIEW FPGA module.The FPGA realization of the DFIG excitation dual-PWM converter is fulfilled by using two FPGA boards in a parallel structure.Combined with the simulation program of wind turbine in the laboratory,the program of the DFIG and the wind turbine have been downloaded to the PXI computer,which is in the Lab VIEW real-time mode,and the communication between FPGA boards and PXI CPU has been designed.Finally,simulations of the different stages of process after the wind turbine generator system started up running and under different disturbances have been made in real time.The rationality and effectiveness of the realization are verified by the analysis of the performance of the converter and the control effect of the DFIG in the simulation process.Moreover,the reproducibility of FPGA makes this realization has more practical meaning.