| 摘要 |
PURPOSE:To prevent generation at the time of stoppage of the vibrations and noises of an induction motor by conducting DC conduction using only two phase when a rotor for the induction motor is rested. CONSTITUTION:When an induction motor 4 is stopped, speed omegagamma as an output signal from a speed detector 5 is brought to zero and slip frequency omegas is also brought to zero-that is, when the induction motor 4 is suspended- the state of torque zero is detected by a zero frequency detector 8, and the operation of a PWM control circuit 7 is stopped. DC currents are output by the combina tion of two elements nearest to a primary current vector I1' by stopping PWM control. |
