JPH0795770A - Ac input power supply unit - Google Patents

Abstract

PURPOSE:To reduce the size of an AC input power supply unit and increase the power factor of the input of the unit, and then, reduce low-frequency ripples in the output of the unit. CONSTITUTION:By supplying input power from an AC input source 1 to an output from a first inverter section 2 through a two-input transformer 5 and rectifier and smoothing circuit 6 and, during the period when the input power is larger than the output power, using part of the input power for charging a capacitor 3, and then, during the other period, discharging part of the output power to the output from the capacitor 3 through a second inverter section 4, the part of the output power other than the part used for charging the capacitor 3 or discharged from the capacitor 3 is only passed through the first inverter section 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC input power supply device which realizes a high input power factor and a low output ripple.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a conventional configuration of an AC input power supply device which realizes a high input power factor and a low output ripple. In this conventional example, an inductor 101, a switch element 102, a diode 103, a capacitor 104, which are connected to the AC input source 1 via a rectifier circuit 9 made of a diode.
In the first power conversion circuit 100 including the first control circuit 105, the input current Ii is approximated to a sine waveform to reduce the high frequency component, thereby increasing the power factor of the input, and the switch elements 201 and 202. A transformer 206 having an input winding 204, an output winding 205, diodes 207 and 208, a rectifying / smoothing circuit 211 including an inductor 209 and a capacitor 210, and a second control circuit 212. In the second power conversion circuit 200, the ripple of the output voltage generated at the output terminal 7 is reduced.

[0003]

According to the conventional example, the two first and second power conversion circuits 100 and 200 are connected in cascade, and the output power is all the two first and second power conversion circuits. Since it has to pass through the power conversion circuits 100 and 200 of 1., there are restrictions on miniaturization and high efficiency of the device.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a compact and highly efficient AC input power supply device.

[0005]

[Means for Solving the Problems] Claim 1 according to the present invention
The AC input power supply device as described in 1 above, a first inverter unit connected to an AC input source, an energy storage element connected to the first inverter unit, and a second inverter unit connected to the energy storage element as an input. An inverter section, a two-input transformer having two input windings and an output winding respectively connected to the first and second inverter sections, and a rectifying / smoothing circuit connected to the output winding, An output terminal connected to the rectifying / smoothing circuit, and a control circuit for detecting an input current and an output voltage and controlling a switch element in the first and second inverter sections are characterized by being characterized.

According to another aspect of the AC input power supply device of the present invention, a first inverter unit connected to the AC input source and a first input winding connected to the output of the first inverter unit are provided. An energy storage element connected to the first inverter section, a second inverter section to which the energy storage element is connected as an input, and a second input winding connected to the output of the second inverter section. Line and the first and second
The input winding of the first winding portion (a), the first winding portion (b) and the second winding portion (c), the second winding portion (d), A first two-input transformer having the first winding portion (a), the second winding portion (c), and a first output winding; the first winding portion (b); A second winding part (d) and a second output winding, and the direction of excitation by the second input winding with respect to the direction of excitation by the first input winding is the first two-input transformer. A second two-input transformer connected in reverse, a rectifying / smoothing circuit connected to the two output windings, an output terminal connected to the rectifying / smoothing circuit, an input current and an output voltage. And a control circuit for detecting the switch and controlling the switch elements in the first and second inverter sections.

[0007]

According to the first aspect of the present invention, the energy storage element is charged with a part of the input power during the period when the input power is higher than the output power, and the period when the input power is lower than the output power. In addition, a part of the output power is supplemented by the discharge from the energy storage element. Thereby, the output power amount other than a part of the power amount charged and discharged in the energy storage element can be supplied only by passing through the one-stage power conversion circuit, and the input high power factor and the output AC frequency ripple reduction can be realized at the same time.

According to the second aspect of the present invention, since the first and second inverter inputs are applied to the first and second two-input transformers, respectively, one input is two inputs. Since it is not biased toward the transformer, the first and second 2
The effective value of the current flowing through the output winding of the input transformer and the rectifying / smoothing circuit connected to it decreases.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the present invention. As shown in FIG. 1, in this embodiment, a first inverter section 2 connected to an AC input source 1, a capacitor 3 as an energy storage element connected to the first inverter section 2, and this capacitor A second inverter unit 4 connected with 3 as an input, and a two-input transformer having two input windings and output windings respectively connected to the outputs of the two first and second inverter units 2 and 4. 5, a rectifying / smoothing circuit 6 connected to the output winding, an output terminal 7 connected to the rectifying / smoothing circuit 6, an input voltage V _i , an input current I _i, and an output voltage V _o are detected. The first two
A control circuit 8 for controlling switch elements (not shown, but described later in FIG. 3) in the second inverter units 2 and 4, and the input current I _i detected by the control circuit 8 is the input voltage. A high input power factor and low output ripple are realized by controlling the on / off period of the switch element so that it has a sine wave shape similar to V _i and that the output voltage V ₀ is constant. .

FIG. 2 shows the input power in the embodiment of FIG.
The relationship between output power and charge / discharge energy is shown. That is, FIG. 2A shows the waveform of the input voltage V _i , FIG. 2B shows the relationship between the input power, the output power, the charge mode and the discharge mode, and FIG. 2C shows the energy storage element. The electric power output to the output terminal 7 without passing through the capacitor 3 is shown. As shown in FIG. 2, by charging or discharging the capacitor 3 with a power having a difference between a sinusoidal input power and a constant output power, the imbalance between the input power and the output power is compensated. Here, the amount of electric power supplied from the first inverter unit 2 through the two-input transformer 5 and the rectifying / smoothing circuit 6 without passing through the capacitor 3 to be supplied to the output is such that the input current waveform is substantially sinusoidal. When controlled, it is about 68% of the total.

That is, according to the present embodiment, the first power conversion circuit 100 in the conventional example of FIG. 9 handles all the energy supplied to the output, whereas the AC frequency ripple of the output voltage V ₀ in the present embodiment is treated. Since the energy handled by the portion including the energy storage capacitor 3 and the second inverter portion 4 added for compensation is only about 32% of the whole, it is possible to make the AC input power supply device compact and highly efficient. .

FIG. 3 is a circuit diagram showing a first concrete configuration of the above embodiment. As shown in FIG. 3, in this embodiment,
A first inverter unit 2 including a rectifier circuit 9 including a diode connected to the AC input source 1, an inductor 21 and switch elements 22 and 23 connected to the rectifier circuit 9.
An energy storage capacitor 3 connected to the inductor 21 via a diode 10, an inductor 41 connected to the capacitor 3, and an inductor 4
Switch elements 42, 43 and inductor 4 connected to 1
The winding 44 wound around the core of 1 and the voltage of the inductor 41 is clamped to the voltage of the capacitor 3 or the output capacitor 63 described later during the simultaneous OFF period of the switch elements 42 and 43 connected to the winding 44 through the diode 45. A second inverter unit 4 including a terminal 46 for
Input windings 51 and 52 respectively connected to the first and second inverter units 2 and 4, a two-input transformer 5 having the input windings 51 and 52 and an output winding 53, and the output winding 53. Rectifying / smoothing circuit 6 including diodes 61 and 62 and an output capacitor 63 connected to
An output terminal 7 connected to the smoothing circuit 6 and an input voltage V _i ,
The control circuit 8 detects the input current I _i and the output voltage V _o and controls the switch elements 22, 23, 42 and 43. The output voltage V ₀ is applied to the terminals 46, 46 of the inductor 41 with the terminal 46 on the diode 45 side as the + side, for example. The current flowing through the inductor 41 rises while the switch element 42 or 43 is on, and decreases while the switch element 42, 43 is off and the voltage of the winding 44 of the inductor 41 is clamped to a constant voltage. .

FIG. 4 shows switching elements 22, 23,
42 and 43 show gate drive voltage waveforms V _{G1 to} V _G4 . As shown in FIG. 4A, in the charging mode, energy is stored in the inductor 21 during the simultaneous ON period of the switch elements 22 and 23, and the capacitor 3 for energy storage is charged during the simultaneous OFF period of the switch elements 22 and 23. Then, electric power is supplied to the output through the two-input transformer 5 while one of the switch elements 22 and 23 is on. On the other hand, in the discharge mode, the switch elements 42 and 43 are switched to the switch elements 22 and 2
It operates in synchronism with 3, and the electric powers of the first and second inverter sections 2 and 4 are simultaneously supplied to the output. As a result, a constant output power can be supplied from the sinusoidal input power. Further, by controlling the simultaneous ON period of the switch elements 22 and 23, the input is made to have a high power factor, and the output power is changed by the simultaneous OFF period of the switch elements 22 and 23 in the charging mode or the ON period of the switch elements 42 and 43 in the discharging mode. Can be controlled.

Although FIG. 3 is constituted by a push-pull step-up / down converter, the present invention can be realized even if the first and second inverter units 2 and 4 or the rectifying / smoothing circuit 6 are configured as a full bridge. It can be realized similarly.

FIG. 5 shows a second specific circuit configuration of the embodiment shown in FIG. As shown in FIG. 5, in this embodiment,
Rectifier circuit 9 composed of a diode connected to single-phase AC input source 1, and inductor 2 connected to the rectifier circuit 9.
1. Switch element 2 connected to this inductor 21
A second inverter unit 2 including a first inverter unit 2 composed of 2, 23, an energy storage capacitor 3 connected to the inductor 21 via a diode 10, and a switch element 42 connected to the capacitor 3. Four
And the input windings 51 and 52 and the output winding 5 which are respectively connected to the outputs of the two first and second inverter units 2 and 4.
A rectifying / smoothing circuit 6 including a two-input transformer 5 having a rectifier 3, a diode 61 connected to the output winding 53 and an output capacitor 63, an output terminal 7 connected to the rectifying / smoothing circuit 6, and the switch. Elements 22, 23, 4
2 and a control circuit 8 for controlling 2.

FIG. 6 shows switching elements 22, 23,
42 shows the gate drive voltage waveforms V _{G1 to} V _G3 of 42. Figure 6
In the charging mode of (a), energy is stored in the inductor 21 during the ON period of the switch element 22, the capacitor 3 for energy storage is charged during the simultaneous OFF period of the switch elements 22 and 23, and during the ON period of the switch element 23. Two
Electric power is supplied to the output through the input transformer 5. Also,
Reset of 2-input transformer 5, that is, 2-input transformer 5
In order to suppress the surge and saturation of the exciting current of the switch, the exciting current can be reduced by generating a voltage in the direction opposite to that when the input winding is excited. Are conducted, and energy is released from the winding 52 to the capacitor 3. On the other hand, in the discharge mode of FIG. 6B, the switch element 42 is turned on to store energy in the two-input transformer 5 while the switch element 22 is on, and power is simultaneously supplied to the output while the switch element 23 is on. Let Here, the input power can be set to a high power factor by controlling the ON period of the switch element 22, and the output power can be controlled by the simultaneous OFF period of the switch elements 22 and 23 in the charge mode and the ON period of the switch element 42 in the discharge mode.

Even if the second inverter section 4 of FIG. 5 has a circuit configuration similar to that of the first inverter section 2,
The present invention can be realized.

FIG. 7 shows a circuit configuration diagram of an embodiment of the invention described in claim 2. In this embodiment, as shown in FIG.
Rectifier circuit 9 consisting of a diode connected to single-phase AC input source 1, and inductor 2 connected to said rectifier circuit 9.
1. Switch element 2 connected to this inductor 21
The first inverter section 2 composed of 2, 23, 24, 25, the first winding section a51, b151 connected in series to the output of the first inverter section 2, and the inductor 21. A capacitor 3 for energy storage connected via a diode 10, an inductor 41 connected to this capacitor 3, switch elements 42, 43, 47, 48 connected to this inductor 41, wound around the core of the inductor 41. Winding 44, switch elements 42 and 48 connected to this winding 44 through a diode 45,
A second inverter unit 4 including a terminal 46 that clamps the voltage of the inductor 41 to the voltage of the capacitor 3 or the output capacitor 63 during the simultaneous off period of 43 and 47, and is connected to the output of the second inverter unit 4 in series connection. Second winding parts c52 and d152, and the first winding part a
51, a second winding portion c52, and a first two-input transformer 5 having an output winding 53; and the first winding portion b1.
51, a second two-input transformer 15 having a second winding part d152 and an output winding 153, diodes 61 and 62 connected to the output winding 53, and the output winding 153.
A rectifying / smoothing circuit 6 including diodes 64 and 65 and an output capacitor 63 connected to the output terminal 7, an output terminal 7 connected to the rectifying / smoothing circuit 6, and the switch element 2
2, 23, 24, 25, 42, 43, 47, 48 and the control circuit 8 for controlling. Here, the second two-input transformer 15 includes the first winding parts a51, b.
With respect to the excitation direction by 151, the second winding parts c52, d
They are connected so that the direction of excitation by 152 is opposite to that of the first two-input transformer 5.

FIG. 8 shows switching elements 22, 23,
24, 25, 42, 43, 47 and 48 show gate drive voltage waveforms V _{G1 to} V _G8 . In the charging mode of FIG. 8A, energy is stored in the inductor 21 during the simultaneous ON periods of the switch elements 22, 23, 24, 25, and only the switch element 24 or 25 is charged in the energy storage capacitor 3 during the ON period. , Only the switch elements 22 and 24 or 23 and 25 supply electric power to the output through the transformer during the ON period. On the other hand, in the discharge mode of FIG. 8B, the switch elements 42, 47, or 43 and 48 are alternately turned on during the period when the switch elements 22, 23, 24, 25 are simultaneously turned on, and the capacitor 3 is charged. Power is supplied to the output. In addition, the switch elements 22, 23, 2
By controlling the simultaneous ON periods of 4 and 25, the input is made to have a high power factor, and the output power is changed by the ON period of only the switching element 24 or 25 in the charging mode and the ON periods of the switching elements 42, 43, 47 and 48 in the discharging mode. You can control.

Note that the first and second inverter sections 2 and 4 in FIG. 7 can be realized in the same manner even if they are constructed by a push-pull step-up / step-down type as shown in FIG.

In each of the above embodiments, the energy storage element may be an inductance, a battery or the like in addition to the capacitor 3.

[0023]

As described above, according to the invention described in claim 1 of the present invention, the first inverter unit connected to the AC input source and the energy connected to the first inverter unit. A storage element, a second inverter section to which the energy storage element is connected as an input, and a second inverter section connected to the outputs of the first and second inverter sections, respectively.
A two-input transformer having one input winding and an output winding, a rectifying / smoothing circuit connected to the output winding, and the rectifying / smoothing circuit.
Since it is composed of an output terminal connected to the smoothing circuit and a control circuit for detecting the input current and the output voltage and controlling the switch elements in the first and second inverter sections, an AC input source and an energy storage element are provided. A two-input transformer having an input winding is connected to each of the inverter sections, thereby realizing a high input power factor and low output ripple with a single-stage power conversion circuit, and thus a compact and highly efficient AC input power supply device. Can be configured.

Further, according to the invention of claim 2,
A first inverter section connected to the AC input source, a first input winding connected to the output of the first inverter section, an energy storage element connected to the first inverter section, A second inverter section to which an energy storage element is connected as an input, a second input winding connected to an output of the second inverter section, and the first and second input windings are respectively connected to a first section. Winding part (a), first winding part (b) and second winding part (c), second winding part (d)
A first two-input transformer having a first winding portion (a), a second winding portion (c), and a first output winding, and the first winding portion. (B) and the second winding section (d) and the second output winding, and the excitation direction of the second input winding with respect to the excitation direction of the first input winding is the first A second two-input transformer connected so as to be opposite to the two-input transformer, a rectifying / smoothing circuit connected to the two output windings, and an output terminal connected to the rectifying / smoothing circuit, Since it is configured by a control circuit that detects an input current and an output voltage and controls the switch element in the first and second inverter units, the first and second
Inverter inputs are applied to the first and second two-input transformers respectively, so that the inputs are not biased to one of the two-input transformers. The effective value of the current flowing through the rectifying / smoothing circuit can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of claim 1 in the present invention.

FIG. 2 is a diagram showing a relationship among input power, output power and charge / discharge energy in the present invention.

FIG. 3 is a diagram showing a first specific circuit configuration in the embodiment of FIG.

FIG. 4 is a diagram showing an example of a gate drive voltage waveform of a switch element according to the embodiment of FIG.

5 is a diagram showing a second specific circuit configuration in the embodiment of FIG.

6 is a diagram showing an example of a gate drive voltage waveform of the switch element according to the embodiment of FIG.

FIG. 7 is a diagram showing a circuit configuration of an embodiment of claim 2;

8 is a diagram showing an example of a gate drive voltage waveform of the switch element according to the embodiment of FIG.

FIG. 9 is a configuration diagram showing an AC input power supply device that realizes a conventional high input power factor and low output ripple.

[Explanation of symbols]

 1 AC Input Source 2 1st Inverter Section 3 Capacitor 4 2nd Inverter Section 5 2 Input Transformer 6 Rectification / Smoothing Circuit 7 Output Terminal 8 Control Circuit 9 Rectifier Circuit 10 Diode 15 15 Input Transformer 21 Inductor 22 Switch Element 23 Switch Element 24 switch element 25 switch element 41 inductor 42 switch element 43 switch element 44 winding 45 diode 46 terminal 47 switch element 48 switch element 51 first winding portion a 52 second winding portion c 53 output winding 61 diode 62 Diode 63 Output capacitor 64 Diode 65 Diode 151 First winding part b 152 Second winding part d 153 Output winding

Claims (2)

[Claims] 1. A first inverter section connected to an AC input source, an energy storage element connected to the first inverter section, and a second inverter section connected to the energy storage element as an input. A two-input transformer having two input windings and an output winding respectively connected to the outputs of the first and second inverters; a rectifying / smoothing circuit connected to the output winding; An AC input power supply device comprising: an output terminal connected to a smoothing circuit; and a control circuit that detects an input current and an output voltage and controls a switch element in the first and second inverter sections. . 2. A first inverter section connected to an AC input source, a first input winding connected to an output of the first inverter section, and energy connected to the first inverter section. A storage element, a second inverter section to which the energy storage element is connected as an input, a second input winding connected to the output of the second inverter section, and the first and second input windings. The wire is divided into a first winding portion (a), a first winding portion (b), a second winding portion (c), and a second winding portion (d), respectively, A two-input transformer having a winding part (a), a second winding part (c) and a first output winding, and the first winding part (b) and the second winding. A line portion (d) and a second output winding, and the direction of excitation by the second input winding is forward with respect to the direction of excitation by the first input winding. Note 1
A second two-input transformer connected to be opposite to the two-input transformer, a rectifying / smoothing circuit connected to the two output windings, and an output terminal connected to the rectifying / smoothing circuit. An AC input power supply device comprising: a control circuit that detects an input current and an output voltage and controls a switch element in the first and second inverter sections.