Design And Research On On-line Vibration Monitoring Of Power Transformer Based On LABVIEW

As our country power industry reform and development of the power of science and technology, people make a claim for higher safe operation .Power transformer is the most important equipment in the power system, which directly affects the safe . operation of the entire power grid .Therefore, in recent years, monitoring of power transformer has been given more and more human and material resources, so the level and accuracy of monitoring raise much. And monitoring methods are diversity. Vibration monitoring is an in vitro monitoring, through vibration acceleration sensor adhered to the body of the transformer to obtain the vibration signal, and then an analysis of the vibration signal, thereby to monitor the operation of transformers. As monitoring in the non-occurrence of electrical connections, it greatly reduces the danger and received much attention. The main work is as follows:(1) Analyze the Vibration principle of power transformerIn this paper, the vibration of the power transformer is analyzed from transformer core and windings, reach conclusion: the vibration is mainly caused by transformer core with no-load; the vibration generated by the core and winding with load and the vibration foundation frequency of core and windings are 100Hz.(2) Research the vibration data processing methods deeplyIn this paper, Wavelet analysis and short-time Fourier transform are used in the vibration of the transformer of the analysis of data processing, which overcomes the traditional shortcomings of spectrum analysis, and makes a preliminary for analytical vibration data of the transformer.(3) Developed the vibration monitoring system for power transformerIn this paper, piezoelectric sensors, signal conditioning modules, card and computer set up the transformer vibration test system. In the formation of the test system, in order to enhance the comparability of data, two vibration signals are acquired at the same time. The transformer vibration data processing system is base on LABVIEW. The function of the system include: data acquisition; vibration spectrum of data analysis; data preservation and playback; time-frequency analysis.(4) Research the vibration of the transformer at different voltage under no-loadA testing transformer is chose to be the research object, using the vibration test system of the transformer, research its vibration state under no-load. Indicate that: the transformer working under no-load condition, along with the no-load voltage increasing, the intensity of the vibration is stronger, Obtaining the vibration of transformer mainly concentrated in the band 300～600Hz under no-load condition.(5) Research the vibration of the transformer on different loadIn this paper, choosing the capacitance as the load, Research the vibration of the transformer By changing the size of the load .The experimental results show that: the intensity of the vibration is stronger go with the load current increasing; Transformer under load of the main vibration band in the 0～150Hz;When the transformer working under load condition, the base frequency of the vibration signal is 100Hz, and contains other the high harmonic waves (200Hz,300Hz and 400Hz,etc), around 1200Hz, frequency components are near zero.