Bridge rectifier operation and power factor correction circuit
AssigneeRaytheon Systems Limited
InventorRaymond Blane
Life of this patent
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Abstract
A power factor correction “PFC” circuit for use in AC-DC conversion comprises first and second pairs of switches connected across input and output rails in a full bridge configuration, and a controller configured to control the operation of the switches such that one pair of switches is switched on and off at an AC input frequency and the other pair of switches is switched on and off at high frequency; and the switching frequency is alternated between the pairs of switches every n cycles of the AC input/output frequency. The circuit may include inductors on both input rails and may be used in a bidirectional power supply.
Claims14
A power factor correction “PFC” circuit for use in AC-DC conversion
- comprising first and second pairs of switches connected across input and output rails in a full bridge configuration, and a controller configured to control an operation of the switches such that:
- one pair of the first and second pairs of switches is switched on and off at an AC input frequency of an AC input signal and the other pair of the first and second pairs of switches is switched on and off at high frequency;
- and
- a switching frequency is alternated between the first and second pairs of switches every n cycles of the AC input frequency where n is an integer;
- wherein an ON/OFF duty cycle of the pair being switched at high frequency of the first and second pairs of switches is alternated between one half cycle of the AC input signal and a next half cycle.
A method of operating a bridge rectifier comprising first and second pairs of switches, for AC to DC conversion, wherein one pair of the first and second pairs of switches is switched at an AC line frequency, the other pair of the first and second pairs of switches is operated at high frequency, and a switching frequency is alternated between the first and second pairs of switches every n cycles of the AC line frequency where n is an integer;
- wherein an ON/OFF duty cycle of the pair being switched at high frequency of the first and second pairs of switches is alternated between one half cycle of the AC input and a next half cycle.
A method of operating a rectifier comprising first and second pairs of switches in a bidirectional power supply comprising:
- for AC-DC conversion:
- switching one pair of the first and second pairs of switches at an AC input frequency, operating the other pair of the first and second pairs of switches at a high frequency, and alternating the AC input frequency and the high frequency between the first and second pairs of switches every n cycles of the AC input frequency where n is an integer;
- for DC-AC conversion:
- the first pair of switches including a first switch and a second switch and the second pair of switches including a third switch and a fourth switch, switching opposing switches in each pair including the second switch and the third switch with a first duty cycle and the other switches in each pair including the first switch and the fourth switch with a second duty cycle, and
- alternating the first and second duty cycles of the opposing switches and the other switches for each change in polarity of an AC output voltage.
Dependencies are inferred from the claim text.