Research And Application Of Monitoring Balance Transformer’s Three Dimensional Surface Temperature

Balance transforms are special oil-immersed transformers which are widely used in traction power supply system. Compared to normal transformers, balance transformers have different structures and a much harsher working environment. However, balance transformers’ falt diagnosis methods are still relied on periodic preventive tests which are gradully eliminated. Obviosly, it is important to design an on-line monitoring system for balance transformers. After the comparison of morden falt diagnosis methods, a condition monitoring system for balance transformers was designed. The system was based on surface temperature method.First of all, the structure and heat-transfer mechanism of balance transformers were discussed in order to prove the possibility of the surface temperature method. This was mainly based on theoretical analysis. After that, some examples of malfunction were collected in order to prove the possibility of the surface temperature method in a realistic way. With the help of finite element analysis and computer simulation, a balance transformer’s heat-transfer process was analyzed. Based on the above, the possibility of surface temperature method was preliminarily proved and some instructions were set.Secondly, based on the fact that transformer’s shell is reliablely grounding, a temperature monitoring system with contact-type temperature sensors was designed. Both hardware and software were included. The software of the computer was thoroughly programmed.At last, taking use of the heat data of a balance transformer, a linear classification machine with margin was designed. Due to samples’ redundancy, the samples’ dimension was reduced. Then the samples were mapped to one dimension higher to make the machine homogeneous. Man made noise was added to enhance the machine’s Robustness. The machine successfully classify the samples and its extension ability was estimated by cross validation.