Fuzzy Recognition Method and Simulation Analysis on Second Harmonic Excitation Inrush Current of Transformer

摘要

With the rapid development of electric power industry in our country, the extra-high voltage power transmission system is widely applied so that the power transformer plays a more and more important role. This not only requires the transformer to quickly protect the circuit system but requires the transformer to be sensitive and reliable. Generally speaking, the method of differential protection is used to deal with some troubles when it breaks down such as the faster actuation time and wrong operation in magnetizing inrush current according to the second harmonic principle and waveform symmetry principle. On the basis of using second harmonic principle, we try to introduce the fuzzy recognition technology and provide a new criterion for the interlock of second harmonic by constructing the function subordination. Finally the simulation analysis is made through MATLAB, whose effect is better.