The Research On On-line Monitoring Of Transformer Vibration And Noise Based On Dc Magnetic Bias

China’s current energy situation presents more than the total、 per capita less and unbalanced regional distribution characteristics, which make large-capacity, long-distance HVDC transmission lines has become a trend in production. HVDC system grounding electrode current will flow into the transformer windings through the transformer neutral point, and resulting in the phenomenon of DC bias. Increased vibration caused by transformer body, accompanied by a lot of noise pollution, or even appear overheating and damage to insulation case.Transformer vibration, noise intensity is the DC bias current is linear, it can be used as an important indicator of transformer DC bias magnetic state. In order to accurately assess the DC bias to the impact of the transformer, the paper involved in the development of the transformer vibration and noise monitoring system. The system in strict accordance with international technical standards, network architecture model, great compatibility, to meet the design requirements of the various modules;it can adapt to different data bus requirements, but can also accept other types of products monitoring module integrated into the system; system self-calibration function automatically corrects the error caused by the temperature difference, the background processing system can efficiently generate the monitoring graphs.Paper systematically analyzes the relationship between vibration amplitude and the DC bias current, compared to the absence of DC bias magnetic transformer running state, improved the evaluation system of transformer DC bias state. The devices show unique advantages,and the device uses the composition of the "thyristor bypass, mechanical switch bypass,container",it could effective inhibition of the DC magnetic bias.