Research On The On-line Detection Method For The Loss And Capacity Of Distribution Transformer

The open-circuit loss, short-circuit loss and capacity are important performance parameters of transformers. High-loss transformers and those which have false data on their nameplate can be discovered through testing on these parameters,and based on testing results we can also forecast the potential failure of transformers. Then, steps can be taken in order to cut losses and maintain power market order.Nowadays, with the transformer coming to the load center on power distribution, a large number of distribution transformers exist within the system, which results in considerable human and material resources needed during the detecting period, and off-line detection seriously affects the sustainability of power supply. So, the method on which performance parameters can be detected more economically and more conveniently is of urgency to power department. Based on this, an on-line measuring method for the capacity and losses of transformers is presented in this paper.The on-line detection method for open circuit loss, short circuit loss and capacity is derived based on the analysis of the structure and working principle of transformers.Then, an on-line detection system is constructed, through which the on-line detection of the transformer capacity and losses is fulfilled. Main task is separated into several parts as follows:â‘ On the study of losses on-line detection method, transformer equivalent circuit was constructed and on-line detection method for load loss, short circuit loss of transformers was also derived based on the analysis of the structure and working principle of transformers. The on-line detection method for open circuit loss and short circuit loss of transformers derived after the calculation of iron loss and copper loss using the primary side electrical parameters and the secondary side electrical parameters of a transformer acquired on-line was proved by simulation results.â‘¡On the study of capacity on-line detection method, advantages and disadvantages of the losses comparison method, impedance voltage method and the three elements method were given out firstly. Then a method based on the combination of short circuit impedance on-line detection method and the three elements method was proposed. Finally, this proposed method was proved feasible by simulation results.â‘¢The whole transformer capacity and losses on-line detection system was built based on the above studies, and mainly completed the design of PC analysis software interactive LabVIEW interface, through which the acquisition of electric parameters, real-time analysis, losses and capacity measurement functions were completed.â‘£Experiment was carried out on the simulation on-line platform constructed in the laboratory based on the method proposed in this paper. And through the analysis of experimental results, it showed that the proposed method is feasible.Finally, this paper summarizes the major research achievements, as well as the existing problems and deficiencies. At the end of this paper, the further researches on this topic are previewed.