Analysis about the tendencies of power quality indices according to the running states of the electric train

As the speed of electric railway gets higher, the stable power supply is very important for the safe operation. In case the electric power of a bad quality is supplied, the electric equipments can not have good performances, and many faults occur. Hence, it is important to find the cause of the problems related to the power quality. We can know the tendency about the power quality in the railway when the power quality indices in the railway can be measured by analyzing several other mechanical data for finding such causes. In this paper, the test method to measure the electric power quality indices according to the running state of the high speed electric railway is introduced, and voltage sag, swell, interruption, and electric transient unlike the existing power quality indices (ex. harmonic and flicker) are analyzed to observe the relation to the running state of the high speed electric railway. Measured power quality indices are compared to other concurrently measured data, and the results of the analysis about the mutual relationships and the tendencies are shown.