The Research Of Digital Implementation Of Measurement For Voltage Fluction And Flicker Based On FPGA

With the rapid development of our country's industry and economy, the sharp increase of loads,especially the increase of impulsive and nonlinear loads,causing voltage fluctuation and flicker,which influence power quality of electric network seriously.According to International Electrotechnical Commission(IEC) standard IEC61000-3-7 and GB12326-2000,the voltage fluctuation and the flicker are taken as the important indexes to judge the power quality.As important indexes to assess the power quality,voltage fluctuation and flicker reflect the power supply quality directly and quickly.However, nowadays,there is no perfect measurement method of digital signal processing in the aspect of the voltage fluctuation and flicker in our country.Therefore,with deeply studying of the voltage fluctuation and flicker measurement technique,the thesis proposes a modern digital signal processing of the FPGA design methodology using the Simulink/DSP Builder.The Simulink model file(.mdl) has been transformed into VHDL by using DSP Builder,so we can avoid the difficulties of manual programming of a system with VHDL and concentrate on the optimization of system algorithm.This method takes full advantage of Matlab/Simulink system modeling,meanwhile we can make use of the parallel execution speed and high accuracy measurement of FPGA.Firstly,the basic concepts,character values and measurement theory of voltage fluctuation and flicker are introduced,then the advantages and disadvantages of the existing methods and devices are discussed in the thesis.According to the IEC standards and national standards of China about the measurement of the voltage fluctuation and flicker,the digital implementation of the voltage fluctuation and flicker which based on the analog simulations is researched,by using digital filter,the digital model of the measurement system for the voltage fluctuation and flicker is designed by the Simulink/DSP Builder tool.Furthermore,the function simulation is obtained by using the ModelSim SE6.1d software,and the timing simulation is obtained by using the Altera's FPGA design software QuartusII6.0.The simulation results show that the digital signal processing design of FPGA based on Simulink/DSP Builder is simple,fast and efficient and it meets the initial system design requirements of the voltage fluctuation and flicker measurement,furthermore,the design provides a new concept for the further researches of the voltage fluctuation and flicker and it has some theoretical and practical values.