Design On Power Quality Online Monitoring Device Based On DSP

The rapid development of power system,and the wide application of power electronic technology make the power pollution become increasingly serious.The power quality has become the electric power department and the user pay more and more attention.Only through the monitoring and analysis,the power quality problems can be found and be improved.This paper firstly analyzes the research background,significance and research status of power quality monitoring device,and gives the specific requirements of the device.The influence index of power quality is introduced briefly,and gives the indicators of national standards and limits.And the detection algorithm of frequency deviation,voltage deviation and three-phase unbalance are briefly explained.The detection principle of voltage fluctuation and flicker is mainly introduced,and the feasibility of IEC flicker meter is verified by MATLAB.A combination method based on comb filter and IEC method is proposed,which can separate interference between harmonic and interharmonics,and it can improve the detection accuracy by DSP.Voltage sag detection needs to take into account both accuracy and real-time.This paper adopts the half cycle refresh RMS value method,and the rationality is verify by MATLAB.Secondly,the hardware system of power quality on-line monitoring device is analyzed in detail,this paper designs a kind of power quality on-line monitoring device based on DSP as the data processing core and ARM as the core of human computer interaction,and briefly introduced the selection of the chip.In the aspect of hardware,the data sampling module and data processing module of the device are designed according to modular design,and the specific design circuit is given.In the aspect of software,this paper introduces the software design of DSP subsystem and ARM subsystem,and gives the software development process of each function module,and develops the system on CCS3.3 and KEIL MDK development platform.Finally,the error analysis of the device is made by voltage,current,harmonics and other signals generated by standard source.The test results show that the device has good detection accuracy,meets the requirements of performance and function,and runs stably.