| 摘要 |
PROBLEM TO BE SOLVED: To reduce harmonic distortion of an input current. SOLUTION: In a period T1, switching elements Q1-Q4 are simultaneously turned on, power is supplied to a load circuit from a capacitor C1, and energy is stored in an inductor L1. In a period T2', the switching element Q1 is turned on, and the energy stored in the inductor L1 is supplied to the load circuit. In the period T3, all of the switching elements Q1-Q4 are not turned on, the energy stored in the inductor L1 is supplied to the load circuit, and the capacitor C1 is charged through an AC power source AC. The periods are changed in time series. That is, an input current Iin is supplied from the AC power source AC only in the period T3, so that a part of a load current IL1 can be served as the input current Iin. The level of the input current Iin at a zero-crossing point of a power source voltage Vs is lowered, thereby enabling to reduce harmonic distortion. |
