| 摘要 |
PURPOSE:Not to superpose a DC voltage upon an AC voltage which is implied to an induction motor, by changing pulse width of the gate pulse according to the ripple component in the DC voltage. CONSTITUTION:A subtractor 30 generates a ripple signal VR subtracting a reference value V' from a DC voltage VO. A control compensator 31 amplifies or attenuates the ripple signal VR according to a inverter frequency signal fI. An adder 32 generates a compensative frequency signal fC by adding the ripple signal VR from the control compensator 31 to the inverter frequency signal fI from an adder 23. This compensating frequency signal fC is fed to a gate pulse generator 24. Therefore the adder 32 compensates the inverter frequency signal fI according to the ripple signal VR. |
