| 摘要 |
PURPOSE:To permit coping with the instantaneous power source voltage drop of 10-15% and prevent the stopping of the title device by a method wherein the constants of a DC reactor and a transformer are selected so as to be required constants in a static Scherbius device effecting the speed control of an induction motor. CONSTITUTION:DC current, obtained by converting the secondary side output of a wound rotor type induction motor 1 forwardly by a forward converter 2 and smoothed through a DC reactor 3, is converted reversely by a reverse converter 4 and is converted into an AC power source through a transformer 5. In this case, the inductance of the DC reactor 3 is determined by considering a DC current upon the instantaneous power source voltage drop and, therefore, the DC current may be smoothed while coping with the instantaneous drop of the power source voltage. The rated secondary voltage of the transformer 5 is determined by the minimum rotating number of the wound rotor type induction motor 1 considering further (0.1-0.15) more. According to this method, the instantaneous drop of the power source voltage of 10-15% may be responded. |
