AC-DC CONVERTER AND METHOD OF CONTROLLING SAME

摘要

Disclosed is an AC-DC converter that is highly efficient within a broad range of load currents, from light loads to heavy loads. The AC-DC converter (1) is provided with: a main circuit that comprises a diode bridge circuit (3), a main inductor (L1), a main switching element (S1), a main diode (D1), an auxiliary inductor (L2), an auxiliary switching element (S2), an auxiliary diode (D2), and a smoothing capacitor (C1) connected in parallel with a load (12); and a controlling means (4). The AC-DC converter (1) feeds power coming from an AC power supply (11) to the DC load (12). During a period wherein the instantaneous value of input current from the AC power supply (11) is less than a prescribed value (Ith), the main switching element (S1) is switched off and power conversion is conducted by hard-switching with the operation of the auxiliary switching element (S2).