| 摘要 |
PURPOSE:To compensate the secondary time constant even in any operating state of a motor by forcibly exciting the secondary magnetic flux, bringing the phase of the secondary magnetic flux into coincidence with that of the secondary magnetic flux in a control circuit to compensate the secondary time constant. CONSTITUTION:When an exciting current is input to an adder 34 by the output of an oscillator 33 to excite it, the secondary magnetic flux is similarly vibrated. The AC component of the secondary magnetic flux is obtained through circuits 36, 37 and an integrator 38 from the output 35 of a search coil. The AC component of the secondary magnetic flux is compared by a circuit 39 with the phase of the secondary magnetic flux from which DC component is removed through a filter, the difference between both is input to a circuit 12, and the time constant is varied so that it becomes 0. Thus, the secondary time constant can be compensated even in any operation state of a motor. |
