| 摘要 |
<p>PURPOSE:To increase the regenerative braking force of a motor by dividing and connecting a brake resistor into a DC power source side circuit and a motor side circuit with respect to a chopper and controlling the current flow rate of a bypass thyristor so that the motor current or voltage becomes a prescribed value. CONSTITUTION:When a chopper 14 is conducted at t=t0, a motor 16 is short- circuitted through a brake resistor 24b. Thus, a motor current iM will increase. When the chopper 14 is interrupted at the time t=t1 equal to the minimum current flowing time, the current iM will flow through brake resistors 24a, 24b and a stop diode 22 to the power source side and will decrease while regenerating the electric power. When a bypass thyristor 26 is conducted at t=t2, the current iR of the brake resistors 24a, 24b is transferred to the thyristor 26, and the current iM will thus again increase. At this time the motor voltage in higher than the power source voltage. When the chopper 14 is again conducted at t=t3, the thyristor 26 is interrupted by the reverse voltage of the differential voltage of the terminal voltage of the brake resistor 24a and the power source voltage.</p> |
