| 摘要 |
PURPOSE:To simplify and reduce the cost of the construction of a safety device for an elevator by stopping the operation of a power inverter when the difference between the output current of the inverter and a command current value exceeds the predetermind set value. CONSTITUTION:Detection current signals in response to the output currents of U and V phases of 3-phase AC outpus of an inverter are inputted to a regulator 22. The regulator 22 has a phase compensator 16, U-phase, V-phase and W-phase PWM comparators 17U, 17V, 17W, base drive circuits 18U, 18V, 18W, U-phase detection current signal generating adder 23, a discriminator 24 and an operation inhibitor 25. When the difference between the command current signal from the compensator 16 and the detection current signal from the adder 23 exceeds the set value, the inhibitor 25 inhibits the operations of the drive circuits 18U, 18V, 18W by the discrimination signal of the discriminator 24. |
