| 摘要 |
PROBLEM TO BE SOLVED: To increase a charging voltage maintaining accuracy by preventing a large current from flowing into the secondary side of a capacitor magnetizer. SOLUTION: The charging voltage Vc of a capacitor bank and the set voltage for charging Vs are compared by a voltage comparator 21. When the charging voltage Vc reaches the set voltage for charging Vs, charging is stopped by a charging stop switch 22. The charging voltage Vc and the set voltage for charging Vs which has been reduced to 85% of the voltage by an attenuator for the set voltage for charging are compared by a speed reduction comparator 24 of a speed reduction controller 23. When the charging voltage Vc is 85% of the set voltage for charging Vs or below, the charging voltage Vc is left as it is but when the charging voltage Vc is 85% or above, it is reduced to 60% of the voltage by an attenuator for charging voltage 26 and then is input into a trigger timing generator 29. The trigger timing generator 29 compares the charging voltage Vc and standard sawtooth waves generated based on a power source frequency 30 and generates a trigger timing. A conduction phase angle of a thyristor for charging is controlled by this trigger timing. |
