| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of overcurrent in the output of a PWM inverter. SOLUTION: This device is constituted of a rectangular wave inverter 1 and the PWM inverter 2. In such a case, an overcurrent control circuit 15 is provided for the device. Thus, the gain of an output current command value Iref is converged to not more than '1' when the output current Iex of the PWM inverter 2 becomes not less than a first setting value m1 by the non-linear excitation characteristic of a link transformer 7. When the output current Iex of the PWM inverter 2 is reduced and it becomes not more than a setting value m2 , the gain of the output current command value Iref is restored to '1'. An overcurrent suppression circuit 15 is provided with a comparator 16 comparing the output current of the PWM inverter 2 with the first and second setting values, a switch 17 which is opened/closed when the output current I.. of the PWM inverter 2 becomes the first and second setting values, a resistor for gain adjustment 18 for converging the gain of the output current command value Iref and a capacitor 19 for executing charging/discharging by the opening/ closing of the switch 17 and increasing/decreasing the output current Iex of the PWM inverter 2. |
