JPH07264859A - Power-factor-improvement rectifying circuit - Google Patents

Abstract

PURPOSE:To improve power factor in accordance with a wide range of a.c. input voltage without providing a plurality of al ternating currents of inductance according to a.c. input voltage, by making the inductance of an a.c. reactor variable according to a.c. input voltage. CONSTITUTION:The main winding N1 of a saturable power choke coil PPC-1 is placed between the winding 2b of a common mode choke coil 2 in an alternating current line 5 and the connecting point of diodes D3, D4 in a bridge rectifying circuit 3. A voltage the level of which corresponds to that of a.c. input voltage is excited in the secondary winding N2 by means of alternating current passing through the main winding N1. The excited voltage is rectified through a rectifying circuit composed of a diode D5 and a capacitor C3 to obtain a d.c. voltage E1. The d.c. voltage is then fed to the emitter of a transistor Q1 through a resistor R5. A voltage obtained by dividing the d.c. output voltage E1 is applied to the base of the transistor Q1. A control current Ic that varies according to variations in the d.c. output voltage E1 is obtained from the collector of the transistor Q1 and windings Nc1, Nc2 are thereby excited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power factor correction rectifier circuit provided for improving the power factor of a power supply circuit, and particularly to a 200 V AC power supply input to a power supply circuit.
It is suitable to be applied to a power factor correction rectifier circuit that uses an AC reactor to improve a power factor for a so-called wide range power source circuit that can handle an AC power source input up to the V system.

[0002]

2. Description of the Related Art As a power supply circuit, a so-called world wide power supply circuit is widely used, which is widely applicable to a wide range AC input voltage of, for example, 100V to 200V. Further, a power factor correction rectifier circuit capable of improving the power factor at the time of rectifying and smoothing is provided for the power supply circuit. As such a power factor correction rectifier circuit, for example, a choke input system is known in which a power choke coil is inserted in an AC power supply line to improve the power factor.

The circuit diagram of FIG. 7 shows an example of a power supply circuit in which a choke input type power factor correction rectifier circuit is provided for the above-mentioned worldwide power supply circuit. A power supply is shown, and both poles of the AC power supply 1 are windings 2a and 2b of the common mode choke coil 2.
And are connected respectively. Also, C _L, which is inserted between the line 4 and line 5 at a later stage of the common mode choke coil 2 forms a low-pass filter with a common mode choke coil 2 shows the across capacitors.

A PC inserted between the common mode choke coil 2 and the input end of the rectifying bridge circuit 3 (connection point of the diodes D ₁ and D ₃ ) on the line 4 side.
C-11 indicates a power choke coil, which is composed of a winding N ₁₁ as shown in the figure. Note that L ₁ shown in parentheses indicates the inductance of the power choke coil PCC-11, which will be described later.

The power choke coil PCC-
SW ₁ connected in parallel to 11 indicates a switch provided for turning on / off the bypass of the power choke coil PCC-11. This switch SW ₁ incorporates, for example, the triac T ₁ shown in the figure as a switch element, and additionally, this triac T 1
It is a hybrid IC that incorporates an on / off control circuit for ₁ etc. In addition, a resistor R ₁₁ and a capacitor C ₁₃
˜C ₁₆ and diode D ₁₅ are external parts for the switch SW ₁ , and in these external parts, a detection voltage obtained by rectifying and smoothing an AC input voltage by a rectifying circuit composed of a capacitor C ₁₃ and a diode D _15. Is obtained.
Then, in the switch SW ₁ , based on this detected voltage,
For example, when 150 V or less is supplied as the AC power supply 1, it is turned on and brought into conduction, and when 150 V or more is supplied, it is turned off and brought into non-conduction. That is, in this case, the switch SW ₁ is turned on when the AC power supply 1 is a so-called 100V system, and is turned off when the AC power supply 1 is a so-called 200V system. The resistor R ₁₁ and the capacitors C _{14 to} C ₁₆ , which are other external components, form a protection circuit for the noise countermeasure of the surge current and the gate signal. Also,
Reference numeral 3 is a rectifying bridge circuit composed of diodes D ₁ , D ₂ , D ₃ , and D ₄ , and the full-wave rectified input voltage is output to the line 6. C ₁ and C ₂ each represent a smoothing capacitor, which smoothes the full-wave rectified output of the rectifying bridge circuit 3 output to the line 6 to obtain a DC smoothing voltage Ei, which is used, for example, for a constant power supply such as a switching power supply circuit at a subsequent stage not shown. Supply to the power circuit.

Next, the PCC ₁₂ represents a power choke coil and has a winding N ₁₂ . This power choke coil PCC-12 is a smoothing capacitor C as shown in the figure.
It is inserted between the connection point of ₁ and C ₂ and the end of the switch SW ₂ . It should be noted that L ₂ shown in () indicates its inductance, which will be described later. In addition, the connection end (diode D) of the power choke coil PCC-12 and the line 5 side of the rectification bridge circuit 3 is connected.
_2, SW ₂ provided so as to be inserted into D ₄ at the connection point) between is a switch for switching the voltage doubler rectification smoothing operation and normal rectification smoothing operation, similarly to the switch SW _1, FIG. The triac T ₂ shown therein is built in as a switch element, and a triac ON / OFF control circuit and the like are also built in to form a hybrid IC. The resistor R ₂₁ , the capacitors C _{23 to} C ₂₆ , and the diode D ₂₅ are external components of the switch SW ₂ . And SW ₁
In the same manner as in the above case, for example, 150 V or less is supplied as the AC power supply 1 based on the detected voltage obtained by rectifying and smoothing the AC input voltage by the rectifying circuit including the capacitor C ₂₃ and the diode D ₂₅ in these external parts. In this case, it is controlled to be turned on to be in a conductive state, and turned off to be in a non-conductive state when 150 V or more is supplied. The resistance R ₂₁ is other external components, the capacitor C ₂₄ -C _26, when the SW ₁ and the noise countermeasures surge current and the gate signal of the TRIAC T ₂ of the time as well the on / off triac T ₂ Forming a protection circuit provided for.

By the way, for a power supply circuit corresponding to a wide range AC input voltage of 100V to 200V,
When trying to improve the power factor by the choke input method, the conduction angle of the alternating current becomes smaller as the alternating input voltage rises. Therefore, if the alternating input voltage is 100 V system, a large current and small inductance power choke coil. Is suitable, and when the AC input voltage is 200 V, a small current and large inductance are suitable. Therefore, in the circuit shown in FIG. 7 described above, the power choke coil PCC-11 is provided with the winding N ₁₁ that can obtain the characteristics of the small current and large inductance corresponding to the case where the AC input voltage is 200V. Further, the power choke coil PCC-12 is constructed by winding the winding N ₁₂ which can obtain the characteristics of large current and small inductance corresponding to the case where the AC input voltage is 100V system. As a result, in the case of the 100V system, the AC current is changed to the power choke coil PCC-11 in accordance with the switching of the paths of the AC currents (charging currents to the smoothing capacitors C ₁ and C ₂ ) in the 100V system and the 200V system which will be described later. Is made to flow, and in the case of a 200V system, an alternating current is made to flow in the power choke coil PCC-12, so that the power factor improvement suitable for each case is performed. As an example, specifically, for the power choke coil PCC-11, the inductance L ₁ may be set to about 60 mH, and for the power choke coil PCC-12, the inductance L ₂ may be set to about ₁₀ mH.

Here, the power choke coil PC is shown in FIG.
An example of the structure of C-11 or PCC-12 is shown. The power choke coil PCC-11 has a structure in which a thin wire winding N ₁₁ for small current is wound around the eye-shaped core 10 formed by punching laminated silicon steel plates, for example. , Power choke coil PCC-12
Then, for example, with respect to the core 10, a thick wire winding N for large current
_It has a structure of winding ₁₂ . It should be noted that G indicates a gap formed in the core.

Therefore, the power supply circuit having the power factor correction rectifier circuit having the configuration shown in FIG. 7 operates as follows. First, when the AC input voltage is 100 V, both the switch SW ₁ and the switch SW ₂ are turned on as described above. Therefore, when the switch SW ₁ is turned on, a path passing through the power choke coil PCC-11 is formed, and a circuit between the connection point of the smoothing capacitors C ₁ and C ₂ and the line 5 is formed via the power choke coil PCC-12. Then, in this state, the current during the period when the AC input voltage is positive is as follows: AC power supply 1 → common mode choke coil 2 winding 2a → switch SW ₁ → diode D ₃ → smoothing capacitor C ₁ → power choke coil PCC -12 → Switch SW ₂ → Common mode choke coil 2 winding 2 b → AC power supply 1 On the other hand, during the period when the AC input voltage is negative, the current is AC power source 1 → winding 2b of common mode choke coil 2 → switch SW ₂ → power choke coil PCC-12 → smoothing capacitor C ₂ → diode D ₁ →
The current flows through the path of the switch SW ₁ → the winding 2a of the common mode choke coil 2 → the AC power supply 1.

That is, when the AC input voltage is 100 V, the voltage doubler rectifying and smoothing operation is performed by the above current path. Further, the power choke coil PCC-11 is passed in this current path, while the AC current flows in the power choke coil PCC-12 as described above. And power choke coil PCC-
Since the inductance L ₂ of the ₁₂ windings N ₁₂ has the large current and small inductance characteristic as described above, the power factor improvement corresponding to the case of the AC input voltage of 100 V system is performed.

Next, when the AC input voltage is 200 V, both the switch SW ₁ and the switch SW ₂ are turned off and become non-conductive. As a result, the path passing through the power choke coil PCC-11 via the switch SW ₁ is cut off, and the power choke coil PCC-1 is cut off.
The second circuit is opened by turning off the switch SW ₂ . Therefore, in this state, the current during the period when the AC input voltage is positive is the AC power supply 1 → the winding 2a of the common mode choke coil 2 → the power choke coil PCC−.
11 → diode D ₃ → smoothing capacitor C ₁ → smoothing capacitor C ₂ → diode D ₂ → common mode choke coil 2 winding 2 b → AC power supply 1 Also,
During a period when the AC input voltage is negative, the current is AC power source 1 → winding 2b of common mode choke coil 2 → diode D ₄ →
The smoothing capacitor C ₁ → the smoothing capacitor C ₂ → the diode D ₁ → the power choke coil PCC-11 → the winding 2a of the common mode choke coil 2 → the AC power supply 1 flows.

That is, when the AC input voltage is 200 V, the bridge rectifier circuit 3 rectifies and the capacitor C
_{Although the} smoothing operation by ₁ and C ₂ is performed and the DC voltage Ei responding to the input voltage is obtained, a current flows through the power choke coil PCC-11 in the current path at this time. Then, the inductance L ₁ of the winding N ₁₁ of the power choke coil PCC-11 is set to, for example, a small current and a large inductance as described above, so that the power factor improvement corresponding to the AC input voltage of 200 V is performed. It will be. Thus, in the case of 100V AC input voltage system and 2
In the case of a 00V system, two types of power choke coils that meet the respective conditions are provided, and by switching between the two switches SW ₁ and SW ₂ , switching of the rectifying and smoothing operation according to the AC input voltage and the power choke coil. If the selection switching is performed, it is possible to obtain a rectifier circuit that improves the power factor in response to a wide range AC input voltage.

[0013]

FIG. 9 shows the relationship between the _AC input voltage V _AC and the power factor of the power factor correction rectifier circuit shown in FIG. 7, for example, where the AC input voltage is 100 V and the load is light. The solid line A indicates the case at the time, and the broken line B indicates the case at the time of heavy load. A solid line C shows a case where the AC input voltage is 200 V and a light load is applied, and a broken line D shows a case where the AC input voltage is heavy. For example, as can be seen from this figure, in any of the cases indicated by the solid line A, the broken line B, the solid line C, and the broken line D, the power factor decreases as the AC input voltage increases. Further, as can be seen by comparing the solid line A and the broken line B, and the solid line C and the broken line D, at the same level of AC input, the power factor is lower in the light load than in the heavy load. That is, each power choke coil PCC of the power factor correction rectifier circuit shown in FIG.
If the inductances L ₁ and L ₂ are fixed values as in -11 and 12, the power factor will vary depending on the load and the AC input voltage. For this reason, the power factor is not actually sufficiently improved in response to a wide range of AC input voltage, load fluctuation, and the like.

Further, in the circuit configuration as shown in FIG.
Two switches SW ₁ and SW ₂ that are on / off controlled by the AC input voltage are required. As described above, since these switches are composed of hybrid ICs, the area occupied by them on the board is considerable, and in addition, a relatively large number of external parts are required as shown in the figure. There is a problem in that the number of parts is increased, and it is very difficult to reduce the board size accordingly, and the cost is increased. Further, the triac T ₁ built in each switch SW ₁ , SW ₂ ,
Since the ON voltage exists at about 1.5 V at T ₂ , for example, the power loss of the switches SW ₁ and SW ₂ is about 3 W in total, and the heat generation of the switches SW ₁ and SW ₂ cannot be ignored. For this reason, it becomes necessary to provide a heat radiating plate or the like, which inevitably leads to an increase in the size of the substrate and the like, and there is a problem in that the rectification efficiency also decreases.

[0015]

In order to solve the above problems, the power factor improving rectifier circuit of the present invention is a power factor improving rectifier that rectifies and smoothes an AC input voltage in which an AC reactor is inserted to output a DC voltage. The circuit is configured to include a voltage detection unit that detects a DC voltage and an inductance variable unit that can change the inductance of the AC reactor based on the detection signal of the voltage detection unit. A control winding to which the detection signal of the voltage detection portion is supplied as a control current is provided as the inductance variable portion, and the main winding inserted into the AC input voltage is wound as the AC reactor. A central magnetic leg and an outer magnetic leg formed by winding the control winding on both outer sides of an E-shaped core consisting of an inner magnetic leg provided on both outer sides of the central magnetic leg. did. Alternatively, the AC reactor is configured such that the control winding is orthogonally coupled to the main winding inserted into the AC input voltage.

[0016]

According to the above construction, since the inductance of the AC reactor can be varied according to the detected AC input voltage, it is not necessary to provide a plurality of AC reactors having an inductance according to the AC input voltage. In addition, a control winding that is connected in a plane or orthogonal to the AC reactor is used as a saturable power choke coil, and a control current of a level that varies according to the AC input voltage is applied to the control winding. By doing so, the inductance of the AC reactor can be continuously changed corresponding to the AC input voltage.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram showing an example of a power factor correction rectifier circuit according to the present invention. The same parts as those in FIG. In this figure, PCC-1 indicates a power choke coil of a saturable type according to this embodiment,
In this power choke coil PCC-1, N ₁ represents the main winding as an AC reactor, and L _{N1 in} ()
Indicates the inductance of the main winding N ₁ . Also, N
Reference numeral ₂ denotes a secondary winding that is excited by the main winding N ₁ to obtain a low voltage to be supplied to a rectifier circuit for inductance control described later, and the number of turns depends on the required DC voltage E ₂ It is set by the turn ratio with the winding N ₁ . Further, the series-connected N _C1 and N _C2 are respectively coupled to the core of the main winding N ₁ to form a power choke coil PCC-1.
The control winding which can change the inductance of is shown.
The main winding N ₁ is connected to the winding 2 b of the common mode choke coil 2 and the bridge rectifier circuit 3 in the AC line 5.
It is connected so as to be inserted between the connection points of the diodes D ₃ and D ₄ of, but may be inserted on the line 4 side. The winding N ₂ has one end grounded and the other end connected to the anode of the rectifying diode D ₅ . Further, in the control windings N _C1 and N _C2 , one end of the winding N _C1 is connected to the ground and the other end is connected to the collector of the transistor Q ₁ .

Next, D ₅ is a diode and C ₃ is a capacitor, and they form a rectifying circuit. Winding N ₂
The alternating current flowing through the main winding N ₁ is, although the voltage level corresponding to the AC input voltage is excited, a diode D _5, by the rectifier circuit consisting of the capacitor C ₃ is excited in the winding N ₂ The generated voltage is rectified to obtain the DC voltage E ₂ . Then, this DC voltage E ₂ is supplied to the emitter of the transistor Q ₁ via the resistor R ₅ . Q ₁
Is a transistor for controlling the control current I _C flowing through the control windings N _C1 and N _C2 . As shown in the figure, the bases are resistors R ₃ and R ₄ connected in series to the line 6 which is a DC output. The voltage obtained by dividing the DC smoothed voltage Ei into a predetermined ratio is applied to the base by being connected to the connection point of. Further, as described above, the DC voltage E ₂ is input to the emitter via the resistor R ₅ , and the collector is connected to the end of the control winding N _C2 . Therefore, in this embodiment, the DC smoothing voltage E is applied from the collector of the transistor Q _1.
It is possible to obtain a variable control current I _C based on the change of i.

Here, an example of a concrete structure of the power choke coil PCC-1 of the present embodiment configured as a saturable AC reactor is shown in FIG. The core 11 of the power choke coil PCC-1 of this embodiment has, for example, a pair of double E-shaped cores 11a and 11b formed in a shape in which E-shaped cores are integrally connected so as to face each other as shown in the figure. It is arranged. Further, a gap G is formed in each of the central magnetic leg and the inner magnetic legs on both outer sides thereof. In addition, this core 1
1a and 11b can be formed by laminating, for example, punched silicon steel plates. The main winding N ₁ and the secondary winding N ₂ are wound around the central magnetic leg of the core 11 formed as described above, and the control windings N are respectively wound around the outer magnetic legs on both outer sides. _C1 and N _C2 are wound. In addition,
In this case, the control windings N _C1 and N _C2 are differentially connected so that an induced voltage due to the current I ₁ flowing in the main winding N ₁ is not generated. Also, the arrow shown by the broken line shows the magnetic path of the main magnetic flux, and the arrow shown by the solid line shows the magnetic path of the magnetic flux obtained by the current flowing through the control windings N _C1 and N _C2 . In this configuration, the leakage magnetic flux leaking from the magnetic circuit of the main magnetic flux is almost absorbed by the outer magnetic leg around which the control windings N _C1 and N _C2 are wound. Therefore, the power choke coil PCC-1 according to the present embodiment has a leakage magnetic flux. Is 1/30 ~ compared to the conventional AC reactor
It has a characteristic that it is reduced to 1/50 and becomes a power choke coil with extremely low leakage flux. In addition, the varistor VDR-1 and the resistor R ₁ are for turning on / off the power switch PW.
A protection circuit that suppresses an overshoot voltage that occurs at the time of turning off is formed.

As a path for the AC current (charging current to the smoothing capacitor Ci) of the power factor correction rectifier circuit of the present embodiment having the above structure, the AC input voltage is 100V system or 200V.
Regardless of the V system, during the period when the AC input voltage is positive, the AC power supply 1 → winding 2a → diode D ₂ → smoothing capacitor Ci → diode D ₃ → main winding N ₁ → winding 2b →
(Power switch SW) → path to AC power supply 1, while in the negative period AC power supply 1 → (power switch SW) → winding 2b → main winding N ₁ → diode D ₄ → smoothing capacitor Ci → diode D ₁ → winding 2a → AC power supply 1 will flow. That is, regardless of the level of the AC input voltage, the AC current flows through the main winding N ₁ for improving the power factor.

Here, FIG. 3 shows a case of heavy load (for example, 200 W).
Power choke coil PCC-1
Of, shows the characteristic of a current flowing through the change control winding of the inductance, for example, when the AC input voltage V _AC is 100V, the AC current I ₁ flowing in the winding N ₁ is a substantially 2A, the At this time, as indicated by the point a, the control current I _C =
40 mA is obtained, and the inductance of the main winding N ₁ becomes 10 mH. Also, the AC input voltage is about 230
In the case of V, the alternating current I ₁ is almost = 1 A, but at this time, as shown by the point b, the control current I _C is set to be 10 mA, and the inductance of the main winding N ₁ is 6A.
0 mH can be obtained. In other words, when the AC input voltage is 100V system, the inductance is small, and when the AC input voltage is 200V system, the large inductance is obtained. The power choke has such characteristics. The cross-sectional area of the core 11 of the coil PCC-1, the gap G, the main winding N ₁ , and the control windings N _C1 , N
_C2 is set.

[0022] Then, as the control current I _C shown in FIG. 3 can be obtained, i.e., the transistor Q _1, the AC input voltage of 100V sometimes 40mA next, so that the AC input voltage 230V sometimes 10 mA, the transistor Q ₁ , Resistors R _{3 to} R ₅ , diode D ₁ , capacitor C
Each component such as ₁ will be selected.

If the power factor correction rectifier circuit of this embodiment is configured as described above, the main winding is designed so that the power factor can be improved in response to a wide range of AC input voltage changes of 100V to 200V. The inductance of N ₁ can be changed. Therefore, one power choke coil
It is possible to improve the power factor corresponding to the AC input voltage of 00V system to 200V system. Further, when compared to the power factor correction rectifier circuit shown in FIG. 7 shown as a conventional example, the switch constituted by the hybrid IC and the external parts around it are also omitted.

FIG. 4 shows the power factor characteristics of the power factor improving rectifier circuit of this embodiment, in which the broken line shows the power factor at heavy load and the solid line shows the power factor at light load. In the present embodiment, since the inductance of the AC reactor continuously changes according to the AC input voltage, as shown in the figure, even under heavy load (dashed line) and light load (solid line), the force is in the range of 100V system to 200V system. It becomes possible to maintain it constant when the rate is 0.7 or more. Further, the difference in power factor between heavy load and light load at the same AC input voltage also shows the conventional power factor characteristic shown in FIG.
As can be seen by comparing with 0, it is reduced to about 0.2 to 0.3 and becomes slight. It should be noted that the power factor characteristics shown in FIG. 4 and the variation of the inductance and the characteristics of the current flowing through the control winding shown in FIG. 3 for realizing this power factor characteristic are examples and can be changed according to various conditions. is there. Further, the DC voltage obtained across the smoothing capacitor Ci is converted into a desired voltage via, for example, a DC-DC converter having a constant voltage characteristic.

Next, another embodiment of the power factor correction rectifier circuit of the present invention will be described with reference to FIGS. In this embodiment, the power choke coil PCC shown in FIG.
-1 is the orthogonal type power choke coil PC of FIG.
The configuration is as shown in C-2. That is, at least for the main winding N ₁ as a power choke coil PCC-2, the control winding N _C1, N _C2 are orthogonal coupling type power choke coil provided so as to be orthogonal ,, Figure 1
It is applied as the power choke coil shown in.

Various structural examples of the power choke coil PCC-2 will be described with reference to FIGS. 6 (a) to 6 (e). The cores 12a and 12b shown in each figure are
For example, it can be obtained by stacking punched silicon steel plates. Power choke coil PCC shown in FIG.
-2, the core 12 is a half eyelet-shaped core 12a and an E-shaped core 1
2b are assumed to be joined so as to be orthogonal to each other,
The main winding N ₁ and the secondary winding N ₂ are wound around the _two middle magnetic legs of the half eye-shaped core 12a as shown in the figure, and the central magnetic leg of the other E-shaped core 12b is wound. Control winding N _C1 , N
_A power choke coil PCC-2 is constructed by winding _C2 . In the case of FIG. 6B, the half-shaped core 12a and the half-shaped core 12b are coupled to each other without a gap so as to be orthogonal to each other to form the core 12. And
For the two middle magnetic legs of the core 12a, the main winding N
_{1. The} power choke coil PCC-2 is constructed by winding the secondary winding N ₂ and the control windings N _C1 and N _C2 around the two middle magnetic legs of the core 12b. . In the case of FIG. 6C, the double E-shaped core 12a and the double E-shaped core 12b are joined to each other without a gap so as to be orthogonal to each other to form the core 12, and the double E-shaped core 12a
The main winding N ₁ and the secondary winding N ₂ are wound around the central magnetic leg of the book, and the control windings N _C1 and N _C2 are wound around the central magnetic leg of the double E-shaped core 12b. Power choke coil PCC-2
Is configured.

In the case of FIG. 6D, the double E-shaped core 12a and the E-shaped core 12b are joined to each other so as to be orthogonal to each other without a gap to form the core 12, and the double E
The main winding N ₁ and the secondary winding N ₂ are wound around the central magnetic leg of the E-shaped core 12a, and the control windings N _C1 and N _C2 are wound around the central magnetic leg of the E-shaped core 12b. Then power choke coil PC
C-2 is constructed.

In the case of FIG. 6 (e), the double E-shaped core 1 is used.
2a and the half-letter shaped core 12b are connected to each other without a gap so as to be orthogonal to each other to form the core 12, and the double E
Main winding N ₁ and secondary winding N with respect to the central leg of the shaped core 12a
₂ is wound, and the control windings N _C1 and N _C2 are wound around the two middle legs of the half eye-shaped core 12b, and the power choke coil P
CC-2 is configured. As described above, all the power choke coils PCC-2 shown in the drawings are configured as low-leakage magnetic flux.
If it is configured as shown in FIG. 6 (c) or (d) in 2, the number of bobbins used when actually winding the winding is two. Further, if the structure is as shown in FIG. 6 (b) or (c), since the cores 12 and 12b are of the same type, only one set of press dies for punching the core plate is required.

The circuit configuration of the power factor correction rectifier circuit of the present invention, the structure of the power choke coil, etc. are not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the present invention. .

[0030]

As described above, the power factor correction rectifier circuit of the present invention varies the inductance of one power choke coil in accordance with the AC input voltage, so that the power factor corresponding to a wide range AC input voltage can be obtained. Since it is possible to improve the rate, it is not necessary to provide a plurality of power choke coils corresponding to AC input voltages of different systems. In addition, the number of parts such as switches that can selectively switch the power choke coil has been reduced, and peripheral parts such as external components and heat sinks can also be omitted, making it easy to reduce the board size, weight, and cost. It has the effect of becoming. In addition, the inductance of the AC reactor is changed by flowing a control current at a level based on changes in the AC input voltage through the control winding, so that the power factor is almost constant with respect to changes in the AC input voltage and changes in the load. It has the effect that it can be kept constant.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a power factor correction rectifier circuit as an embodiment of the present invention.

FIG. 2 is a perspective view showing the structure of a power choke coil of this embodiment.

FIG. 3 is an explanatory diagram showing a DC superposition characteristic of the power choke coil of the present embodiment.

FIG. 4 is an explanatory diagram showing a power factor improving characteristic of the present embodiment.

FIG. 5 is a circuit diagram showing a power choke coil according to another embodiment of the present invention.

FIG. 6 is a perspective view showing the structure of a power choke coil of another embodiment.

FIG. 7 is a circuit diagram showing a power factor correction rectifier circuit in a conventional example.

FIG. 8 is a perspective view showing a structure of a power choke coil in a conventional example.

FIG. 9 is an explanatory diagram showing power factor improvement characteristics in a conventional example.

[Explanation of symbols]

1 AC power supply 2 Common mode choke coil 3 Rectifier bridge circuit 4, 5, 6 line PCC-1, 2 Power choke coil N ₁ Main winding N ₂ Secondary winding N _C1 , N _C2 Control winding C _L Across capacitor Ci Smoothing capacitor VDR-1, 2 Varistor C ₁ capacitor R _{1 to} R ₅ resistance D ₅ diode 11, 12 core

Claims (3)

[Claims] 1. A power factor correction rectifier circuit for rectifying and smoothing an AC input voltage in which an AC reactor is inserted to output a DC voltage, wherein voltage detection means for detecting the DC voltage and detection signals for the voltage detection means are provided. A power factor correction rectifier circuit comprising: an inductance varying means for varying the inductance of the AC reactor based on the above. 2. A power factor correction rectifier circuit for rectifying and smoothing an AC input voltage having an AC reactor inserted therein and outputting a DC voltage, wherein voltage detection means for detecting the DC voltage and detection signals for the voltage detection means are provided. A control winding is provided that is supplied as a control current to vary the inductance of the AC reactor, and the AC reactor includes a central magnetic leg around which a main winding inserted into an AC input voltage is wound, and a central magnetic leg thereof. A power factor improving rectifier circuit characterized in that an outer magnetic leg around which the control winding is wound is provided on both outer sides of an E-shaped core composed of a medium magnetic leg provided on both outer sides of the leg. 3. The AC reactor according to claim 2, wherein the AC winding is configured such that the control winding is orthogonally coupled to the main winding inserted into the AC input voltage. Power factor correction rectifier circuit.