Resonant converter with auxiliary resonant components and holdup time control circuitry

摘要

A resonant power converter is provided with auxiliary circuit branches and control circuitry for switchably coupling the auxiliary branches to resonant circuit components during holdup times. Auxiliary branches are coupled in parallel with any one or more of a resonant inductor, a resonant capacitor, and a magnetizing inductive winding via respective switches. When a holdup time condition is detected in accordance with, for example, a drop in the mains line voltage, the switches are controlled to adjust the corresponding inductance or capacitance for the duration of the holdup time condition or otherwise for a predetermined duration. The power converter in normal operation is configured for high efficiency and in a holdup time operation is configured to produce sufficient holdup time.

主权项

1. A resonant power converter comprising:
an input power conversion switching circuit comprising a plurality of power conversion switches coupled to a line voltage input to the power converter; a series resonant circuit coupled to an output side of the power conversion switching circuit and comprising a resonant inductance circuit, a resonant capacitance circuit, and a magnetizing inductance circuit; wherein at least one of the resonant inductance circuit, the resonant capacitance circuit, and the magnetizing inductance circuit in the series resonant circuit further comprise at least first and second circuit branches and a switch controllable to regulate an inductance or capacitance value corresponding to the respective circuit; and a control circuit effective to
detect a holdup time condition associated with a line voltage failure, andgenerate control signals to adjust a switch state for the switch in the series resonant circuit in accordance with determining a first operating mode associated with the holdup time condition or a second operating mode associated with normal operation of the converter.