| 摘要 |
PURPOSE:To prevent an erroneous reversing operation by performing an output limitation of a current regulator so as a power source side converter to stay on a reverse converting operation when a change over instruction processor is generating a reverse torque instruction. CONSTITUTION:When a motor becomes to start a reverse rotation by whatever causes after the motor speed has become zero, the motor induced voltage phase becomes to a reverse phase and a motor side converter 2 performs a reverse converting operation without any change over operation at a pulse distributor 12. By this the converter a direct current side voltage of which becomes to reverse again and a power source side converter 1 becomes to enter into an orderly converting operation. At this time a motor torque direction is different from that at a regenerative braking time, an output voltage of a speed regulator 8 is a negagtve polarity same as at a regenerative braking time, an insturction generated by a change over insturction processor 11 is a reverse torque instruction same as at a regenerative braking time and a switch S becomes to be maintained ''on''. In this manner an output voltage of a current regulator 9 stays at an output limitation value corresponding with an ignition angle of a reverse converting range of a phase angle 90 deg. vicinity established by an establisher VR, can not shift to a negative polarity to accelerate to a reverse rotation direction. |
