POWER FACTOR CORRECT CURRENT RESONANCE CONVERTER

• US 20120063174A1
• Filed: 09/14/2011
• Published: 03/15/2012
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: KUWABARA, Koji, Sato, Tadahiko
• Granted Patent: US 8,824,170 B2
• Time in Patent Office: Days
• US Class Current: 363/21.02
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A power factor correct current resonance converter is disclosed which eliminates interference of switching operations between two cascade-connected converter circuits. The power factor correct current resonance converter includes a current resonance converter circuit having switches, a resonance capacitor, a resonance inductor, a transformer, diodes, a smoothing capacitor, and a control circuit. The power factor correct current resonance converter also includes a power factor correct converter circuit having a choke coil, a diode, a smoothing capacitor, and a switch. The switch is turned on or off in response to a voltage produced in a winding of the transformer. Thus, the switching operation of the power factor correct converter circuit is performed in synchronization with the switching operation of the current resonance converter circuit, so that interference of the switching operations is eliminated. In addition, since a dedicated control circuit is not required, the cost can be reduced.

Claims

1. A power factor correct current resonance converter comprising:

a current resonance converter circuit having a switch; and

a power factor correct converter circuit cascade-connected in a previous stage of the current resonance converter circuit, the power factor correct converter circuit having another switch,

wherein switching operation of the switch of the power factor correct converter circuit is performed in synchronization with switching operation of the switch of the current resonance converter circuit.

2. The power factor correct current resonance converter according to claim 1,

wherein the switch of the current resonance converter circuit is a first switch,

wherein the current resonance converter circuit further includes:

a second switch connected in series with the first switch;

a resonance circuit connected to one of the first and second switches, the resonance circuit including a resonance capacitor and a resonance inductor;

a transformer connected to the resonance circuit, the transformer having a first winding provided on a primary side and a second winding, a voltage being produced in the second winding in response to turn-on/turn-off of the first switch and the second switch, and the transformer additionally having a winding on a secondary side;

a rectifying/smoothing circuit connected to the winding on the secondary side of the transformer; and

a control circuit turning on or off the first switch based on the voltage produced in the second winding,

wherein the switch of the power factor correct converter circuit is a third switch,

wherein the power factor correct converter circuit further includes a choke coil having one end receiving a voltage provided by rectifying a commercial alternating-current input power source, a diode connected to the other end of the choke coil, and a smoothing capacitor smoothing a current passing through the diode,

wherein the third switch switchably connects a connection point of the choke coil and the diode to a low potential side of the smoothing capacitor, and

wherein the third switch is turned on or off in response to the voltage produced in the second winding of the transformer.

3. The power factor correct current resonance converter according to claim 1,

wherein the switch of the current resonance converter circuit is a first switch,

wherein the current resonance converter circuit further includes:

a second switch connected in series with the first switch;

a resonance circuit connected to one of the first and second switches, the resonance circuit including a resonance capacitor and a resonance inductor;

a transformer connected to the resonance circuit, the transformer having a first winding provided on a primary side and a second winding, a voltage being produced in the second winding in response to turn-on/turn-off of the first switch and the second switch, and the transformer additionally having a winding on a secondary side;

a rectifying/smoothing circuit connected to the winding on the secondary side of the transformer; and

a control circuit turning on or off the first switch based on the voltage produced in the second winding,

wherein the switch of the power factor correct converter circuit is a third switch,

wherein the power factor correct converter circuit further includes a choke coil having one end receiving a voltage provided by rectifying a commercial alternating-current input power source, a diode connected to the other end of the choke coil, and a smoothing capacitor smoothing a current passing through the diode,

wherein a connection point of the choke coil and the diode is connected via a backflow preventing diode to a connection point of the first switch and the second switch to provide the first switch with a function of the third switch, and

wherein the third switch is turned on or off in response to the voltage produced in the second winding of the transformer.

4. The power factor correct current resonance converter according to claim 2, wherein the choke coil has a winding provided with a tap, and the diode and the third switch are connected to the tap or an end portion on an opposite side to a side receiving the voltage provided by rectifying the commercial alternating-current input power source to allow a change in a step-up ratio of the power factor correct converter circuit.

5. The power factor correct current resonance converter according to claim 2, wherein the power factor correct converter circuit further includes an energy transfer capacitor and another choke coil between the choke coil and the diode to provide an SEPIC converter.

6. The power factor correct current resonance converter according to claim 2, wherein the second switch is driven by the control circuit such that the second switch and the first switch are alternately turned on and off.

7. The power factor correct current resonance converter according to claim 2, wherein the transformer has a third winding on its primary side, and the second switch is turned on or off in response to a voltage produced in the third winding.