| Power quality directly affect the economic efficiency of industrial production, related to the security of the entire grid. In recent years, as China continues to accelerate the process of industrialization, the type and quantity of electrical equipment increased year by year, the introduction of a large number of non-linear grid, impact resistance, asymmetric load, causing serious harm to the power quality, power quality is good or bad, and how to evaluate how to solve power quality problems have become one of the key research areas of power system studies.In this paper, the superposition of power quality disturbances (two or more types of disturbances occurring simultaneously case) related issues, domestic and international power quality disturbances analysis algorithms depth study proposes the use of wavelet threshold de-noising technology, power quality perturbation analysis algorithm, clustering empirical mode decomposition (EEMD) method are combined to solve power quality disturbances superposition. And combining this method with embedded Linux technology, Linux systems, such as multi-threading technology designed a superposition of power quality disturbances recognition system, enabling quick and accurate identification of power quality disturbances superposition type, thus providing data for the optimization of power quality support, so that the grid system is running at its best. The main article reads as follows:Firstly, domestic and international power quality monitoring and power quality disturbances conducted a situation analysis algorithm analysis, combined with the advantages and disadvantages of various monitoring methods and analysis of algorithms, to identify additive for power quality disturbances, determine the overall design of this article.Secondly, the disturbance signal de-noising methods:wavelet threshold de-noising method analysis and simulation in Matlab software, the perturbation signal analysis methods:clustering empirical mode decomposition research and analysis. and simulation algorithm in Matlab software.Again, given the overall design of the system hardware, chip selection conducted according to the hardware design, including the choice of a microprocessor chipã€FLASHã€RAMã€A/D sampling chips, the design of voltage, current conditioning circuit, introduced A/D sampling chip circuit, FLASH circuit, RAM circuit.Then, given the overall design of the system software, detailing the embedded Linux system and its characteristics, Linux multithreading technology, given the system software environment to build and debug process information. Under the Linux system using multi-threading technology to achieve a Linux cluster mode decomposition programming experience.Finally, the superposition of several typical types of disturbance signal decomposition, the resulting data were uploaded to the network Labview software shows the experimental results show that the system achieved high precision real good recognition of power quality disturbance signal superposition, in order to improve power quality problems and formulate relevant power quality control measures provide a basis for the final of the article summarized the work proposed to be further improved and resolved. |