The Monitoring And Evaluation Of Transient Voltage Fluctuation

With the wide application of large-scale sensitive electronic devices such as the computer and adjustable speed driver in the power system, transient voltage fluctuation of power quality does great harm to it. In order to improve power quality, the first problem to be settled is to monitor and analyze on transient voltage fluctuation.The paper concretely researches on the monitoring and evaluating transient power quality based on the basic theory of ITIC curve in USA and IEEE standard 1159-1995.The aim of this paper is to complete the software of monitoring and evaluation of transient voltage fluctuation based on the hardware platform provided by the laboratory. The content of the research includes two sections: monitoring transient voltage fluctuation signals on-line in a long term; evaluating transient power quality off-line. The key of the first part is to identify and grab of transient voltage fluctuation signals and resolve the problem of compression and conserve long-termed monitored data. In the second part, using Mallat algorithm, the wavelet transform modulus maxima of singularity is extracted through multiresolution decomposition. By which, the accurate location of the duration and RMS Voltage for the event of transient voltage fluctuation can be realized. The result proves that it needs farther theory research in the future.By means of the virtual instrument the paper designs the monitoring and evaluation software. The processes of simulation and on-line monitor verify the feasibility and reliability of this software. The paper anticipates that this software can provide reliable and valid data and information of transient voltage fluctuation in order to farther analyze transient problems of power quality and take measure to improve power quality.