| 摘要 |
PURPOSE:To enable sure detection of a trouble irrespective of a distance from a power transforming device, by monitoring the impedance of a feeder line and a unit propulsion winding, and thereby detecting the trouble. CONSTITUTION:A counter electromotive voltage operating element Eem receives a speed signal and a distance signal from a frequency operating element VF processing a vehicle position detection signal PD and a distance operating element PDS, respectively, and operates a counter electromotive voltage. The first impedance operating element CAL1 operates a measured impedance based on the output voltage and output current of a power transoforming element CC and on a counter electromotive voltage signal from the counter electromotive voltage operating element Eem. The second impedance operating element CAL2 reads a reference impedance based on the speed signal and the distance signal. A comparison element COM compares the measured impedance with the reference impedance, and when the difference between them reaches a set value, an abnormality signal is delivered via an output element OUT. |
