| 摘要 |
PURPOSE:To efficiently operate an induction motor by connecting two choppers in parallel, and alternately sharing load currents, thereby reducing the pulsation of the current. CONSTITUTION:A chopper section is composed of GTO elements GTO1, GTO2 and intermittently short-circuited. A signal of a speed reference circuit RF is input to a speed controller NC, a signal of a speed detector TG is input to the controller NC to control the speed, the output signal of the NC is input to a current controller CC, the signal of a current detector SH is also input to the CC to control the current, and the output of the CC is input to a conduction rate controller PHC. The output signal F of a chopper frequency oscillator F0 is input to the PHC, which applies GTO1 ON signal S01 and GTO1 OFF signal SF1 to a GTO1 gate GA1 and GTO2 ON signal S02, GTO2 OFF signal SF2 to a GTO2 gate circuit GA2, and the GA1, GA2 control to conduct the GTO1, GTO2 elements on the basis of the signal. |
