Analysis of current characteristics of transformer bias caused by subway stray current based on measured data

The metro stray current, as the driving source which causes the magnetic bias of the urban network transformer, has the characteristics of rapid change, complex propagation path, and many influencing factors.It’s unknown where the stray current leaks from, and its specific value cannot be obtained through measurement methods.Therefore, this paper studies the characteristics of transformer neutral magnetic current bias based on the measured data and fault recording data in the process of measurement, and analyzes the influence of stray current on transformer in urban network.

Hierarchical Information Fault Diagnosis Method for Power System Based on Fireworks Algorithm

Power system fault diagnosis is an important means to ensure the safe and stable operation of power system. According to the specific situation of China’s current power grid automation level, a hierarchical fault diagnosis method based on switch trip signal, protection information and fault recording information is proposed. This method can not only diagnose simple fault and complex fault, but also judge fault type and phase, and complete fault location, which provides reliable guarantee for operators to quickly remove fault and resume operation. The diagnosis method based on this principle has good application effect in simulation test.