Design Of Power Quality Monitoring System Based On Nios Ⅱ

Along with the development of economy, more and more attention is paid on the reliability of electrical power system and the quality of electric power. As the nonlinear and the impact of the voltage have been used widely in the daily life and electric power system, power pollution becomes more serious. So, it is an urgent problem to monitor and analysis the power quality reliably and accurately.In allusion to the problem above, the development situation of power quality monitoring was analyzed in this thesis firstly. Then, several models of power quality monitoring system based on DSP, ARM etc. were comprehensive compared. For the satisfaction of speediness, dependability, high precision, supporting complex algorithms and keeping real-time, the scheme of power quality monitoring system based on Niosâ…¡was designed by using the technology advantages of SOPC(be cut, scalable and upgradable). The researching and designing of signal conditioning and A/D sample module, frequency module, FFT module and man-machine interaction keyboard display module were emphasised. Each of the functional module's software is designed with VHDL. The SDRAM and SRAM were used as program memory and data memory respectively. Through testing the system data of three phase voltage and current, frequency, parameters of harmonic and unbalance-pos, the results were displayed on the LCD by calculating the monitoring data. Therefore, the status of power grid can be reflected at the monitoring point.The monitoring system of electric power quality based on Niosâ…¡technology has the advantages of highly integration, short developing period, low design cost, reconfiguration and so on. The system's flexibility and expansibility are improved effectively. This designing method has positive effection to the development of electric power quality monitoring technology.