| 摘要 |
PURPOSE:To judge whether an excitation circuit shorts or not, by detecting current pulsation on the primary side of an induction machine. CONSTITUTION:An induction machine 1 is excited by a cycloconverter 2 and performs delivery and acceptance of power with a system 5. A current transformer 10 for meter is provided on the stator side of this induction machine 1, the signal of which is inputted into an excitation circuit short-circuit device 7. This output signal is led to a current amplitude measuring device 8 through a filter 6. At the time dividing a cycle in twelve equal parts, the current amplitude measuring device 8 samples an instantaneous value of the current, equalizes its absolute value and finds out the current amplitude I. The current amplitude I is sampled by a pulsation discriminator 9, with which the pulsation is detected. |
