| 摘要 |
PURPOSE:To suppress the voltage fluctuation of a DC intermediate-circuit and suppress current oscillation, by changing output frequency according to the voltage change of the DC intermediate-circuit. CONSTITUTION:Signal in proportion to output frequency applied from a frequency setting unit 5 is added to output from a voltage change rate detection circuit 3, at an adding point 6, and is applied to the input 2a of a PWM(pulse width modulation) signal generation circuit 2. When the change component Vdc of DC intermediate-voltage is increased, then in proportion to the increased component, the output frequency is slightly increased. When the change component dc is reduced, then in proportion to the reduced component, the output frequency is slightly reduced. As a result, current oscillation is suppressed. |
