Research On Recognition Of Power Quality Overlapped Disturbances

With the booming economy,people’s living standards have improvedsignificantly, the grid appears in a wide variety of electrical equipment,electricalequipment,rich people get a great convenience,but this convenience has led directlyto the power grid pollution.The so-called three-phase power grid pollution refers tothe standard cosine voltage\current waveform of the original transmission griddistortion or phase\three-phase frequency deviation caused by theimbalance,flicker,harmonics and other issues.Its mainly by the electrical equipmentwith the load or impact load caused by asymmetry.These power quality problem isnot only a serious threat to the security of the entire grid operation,may also causeirreparable damage,such as loss of precision instruments,and therefore to study andsolve the problem of power quality issues have become the focus of power systemdevelopment.Studies of power quality problems must first be set accurately reflect real-timepower quality disturbances happening detection system.Existing power qualitymonitoring system, including some foreign companies introduced power qualityanalysis instrument has advantages,but they can only recognize a single powerquality disturbances,and the emergence of power quality disturbances often are twoor more than two superimposed situation Therefore,this paper mainly additive forpower quality disturbances recognition method to study,and structures asuperposition of power quality monitoring proving system in MIPS as the core ofhardware and in the embedded linux as the core of software.System platformembedded linux system,the algorithm using ensemble empirical modedecomposition(EEMD) method,the method of preparation of multi-threadedprogramming linux EEMD algorithm.Hardware structure of The experimentalsystem is based on frequency of32to400Mhz processor RTL8196c and softwareuses multi-threaded linux system on10parallel threads to handle three to six voltage and current data,a receiving thread,a sending thread,two monitoring thread assuranceprogram will not go into an infinite loop or runaway other conditions occur.The system is basic on EMD method and Hilbert transform,then uses EEMDmethod to decompose power quality overlapped disturbances to identify thedisturbance types in the signal,in order to improve power quality issues and relatedpower quality control measures was developed to provide basis.