Research On Power Quality Monitoring Device Based On DSP

In the contemporary power system,the continuous application of a large number of power electronic devices,impact loads and other non-linear loads lead to the decline of power quality,Various kinds of power quality problems are getting worse which causes great concern in the power supply sector and the electricity user community.On the one hand,these problems can seriously endanger the safety economy and stable operation of the power system.On the other hand,it also causes serious damage to electrical equipment and result in huge economic losses.The accurate and timely analysis of various power quality problems based on data is a prerequisite for the governance and improvement of power quality problems.Therefore,it is particularly important to monitor power quality related parameters accurately in real time.This article first elaborates on the basic concept of power quality,and then gives the definition of power quality indicators and the corresponding calculation methods.For harmonic and interharmonic detection algorithms,the FFT algorithm and Prony algorithm are emphatically studied and the two methods are simulated and compared on the same signal in MATLAB.Aiming at the disadvantage that Prony algorithm is sensitive to noise,a parameter identification of harmonics and inter-harmonics method based on CEEMD-WPT and Prony algorithm has been put forward.The simulation results show that the method is effective and has better identification results.According to the requirements of the national power quality monitoring device technical specification,a power quality monitoring device based on the data processing chip TMS320F28335 and the data acquisition chip AD7606 was designed,Including the overall device hardware design,software programming and upper computer display interface design.The hardware part includes signal conditioning module,AD sampling module,serial communication,storage module and DSP minimum system.Modular design thinking is adopted in software programming to facilitate debugging.Software programming is based on CCS6.0 development environment using C language to write DSP related programs,including DSP main program,sampling program and data processing program.The upper computer display interface is based on the LabVIEW software and realizes the monitoring data reception as well as waveform and result display.