The Method And Apparatus For Monitoring Mechanical Defects In Main Transformer Of Electric Railway By Impedance Change

摘要

PURPOSE: A method and an apparatus for monitoring mechanical defects of a main transformer in an electric railway vehicle using impedance changes are provided to monitor the status of a main transformer more accurately and directly by monitoring changes in impedance, relation between voltage and current, in the main transformer. CONSTITUTION: A monitoring apparatus comprises a voltage sensor(100), a current sensor(110), a data collecting unit(120), a calculating unit(130), and a control unit(140). The voltage sensor measures the primary side input voltage of a main transformer at a fixed cycle. The current sensor measures the secondary and tertiary side output current of the main transformer at the fixed cycle. The data collecting unit collects measured data from the voltage and current sensors and stores the data in a memory. The calculating unit calculates impedance according to frequency through FFT of the data stored in the data collecting unit. The control unit compares the impedance calculated by the calculating unit with the impedance measured in the previous cycle in order to determine whether the impedance exceeds a set range.