| 摘要 |
PURPOSE:To make it possible to control an output voltage to be prescribed in relation to the fluctuation of an input voltage by filtering out a current frequency component inherent in a protective apparatus from a return-wire current. CONSTITUTION:A feed forward command ALi to output a prescribed output voltage for an input voltage Vi is computed by a feed forward controller 11, while a feedback command ALo to zero a difference Vd between a voltage Vc set by an output voltage setting unit 12 and the output voltage Vo is computed by a feedback controller 14. A specific frequency component extractor 16 extracts a current Ifc of the component of a frequency fc from a return-wire current I. A phase shifter 18 controls a phase of canceling the current Ifc and a current gain controller 19 converts this phase into a current control correction command ALx. A modulated wave generating part 20 generates a modulated wave of percentage modulation AL obtained by an adder 15. A carrier signal generating part 21 generates a carrier signal and a switching signal generating part 22 generates a switching signal G from the modulated wave and the carrier signal. |
