WO2014188662A1

WO2014188662A1 - Coil structure

Info

Publication number: WO2014188662A1
Application number: PCT/JP2014/002267
Authority: WO
Inventors: 崎山　一幸; 悟菊池; 元彦藤村; 加藤　彰
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2013-05-21
Filing date: 2014-04-22
Publication date: 2014-11-27

Abstract

A coil structure is configured, such that an occurrence of a surge voltage is suppressed, from a magnetic core (101), a coil (102), and link conductors (103a, 103b) which are short-circuit conductors which configure closed circuits. The magnetic core (101) further comprises a core leg (110). The coil (102) is positioned in the circumference of the core leg (110). A primary magnetic field is emitted in the core leg (110) by an electrical current flowing in the coil (102). The link conductors (103a, 103b) are positioned in locations which are in contact with the coil leg (110) and which link with the primary magnetic field. The coil (102) and the link conductors (103a, 103b) are electrically insulated from one another.

Description

Coil structure

The present disclosure relates to a coil structure such as a reactor used for a power supply for a switching power supply.

As a conventional technique for suppressing surges in a magnetic component composed of a magnetic core and a coil, there is a case for suppressing surges when turning on / off an electromagnet as shown in Patent Document 1, for example. . In Patent Document 1, an inductance value is reduced by disposing a non-magnetic metal portion between magnetic cores, and a separation delay and a surge due to the influence of residual magnetization, which are problems of an electromagnet, are suppressed.

Japanese Examined Patent Publication No. 7-85448

抑制する It has been required to suppress surges that occur during transients when the current flowing through the coil changes, such as during switching operations.

One aspect of the present disclosure includes a magnetic core, a coil, and an interlinkage conductor portion that is a short-circuit conductor constituting a closed circuit, the magnetic core has a core leg, and the coil is disposed around the core leg. The main magnetic flux is generated in the core leg by the current flowing through the coil, the interlinkage conductor portion is disposed at a position in contact with the core leg and interlinkage with the main magnetic flux, and the coil and the interlinkage conductor portion are electrically connected to each other. It takes the configuration of an insulated coil structure.

According to the present disclosure, it is possible to suppress a surge that occurs during a transient in which the current flowing through the coil changes.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic for demonstrating the structure of the reactor of Embodiment 1, Comprising: (a) is a perspective view, (b) is the front view which looked at the coil from the axial direction, (c) is AA sectional drawing. is there. It is the schematic for demonstrating the structure of the reactor of a comparative example, (a) is a top view, (b) is a perspective view, (c) is the front view which looked at the coil from the axial direction, (d) is C FIG. (A) is a circuit diagram for demonstrating the example of the switching operation of a reactor, (b) is a wave form diagram which shows that a big surge voltage generate | occur | produces in the terminal of a diode in the case of the reactor of a comparative example. It is a structural diagram for demonstrating the magnetic field simulation model of the reactor of a comparative example. FIG. 4 is a structural diagram for explaining a reactor magnetic field simulation model according to the first embodiment; It is a comparison figure of magnetic flux distribution by magnetic field simulation, (a) is magnetic flux distribution at the time of the maximum coil current of the reactor of a comparative example, (b) is magnetic flux distribution at the time of the maximum coil current of the reactor of Embodiment 1, respectively. Show. It is a circuit diagram for demonstrating the coupled simulation model of the magnetic field analysis and circuit analysis of a reactor. It is a comparison figure of a switching voltage waveform by coupled simulation of magnetic field analysis and circuit analysis, (a) is a waveform figure in the case of the reactor of a comparative example, (b) is a waveform figure in the case of the reactor of Embodiment 1. is there. FIG. 4 is a schematic diagram for explaining another configuration example of the reactor according to the first embodiment, where (a) is a plan view, (b) is a front view of the coil viewed from the axial direction, and (c) is BB. It is sectional drawing. (A), (b), (c), (d), (e), (f), and (g) are circuit diagrams which show the detailed example of the induced current control part in FIG. 1 or FIG. FIG. 6 is a schematic diagram for explaining a configuration of a power supply circuit according to a second embodiment. (A), (b), (c), (d), (e), (f), and (g) are circuit diagrams which show the detailed example of the induced current control part in FIG. FIG. 6 is a cross-sectional view for explaining a configuration example of a coil structure according to a third embodiment. (A) is a circuit diagram for demonstrating the example of switching operation at the time of using the coil structure of FIG. 13 as a reactor, (b) is a large surge voltage at the terminal of a diode in the case of the reactor of a comparative example. It is a wave form diagram which shows that generate | occur | produces. (A) is a switching waveform figure in the case of the reactor of a comparative example, (b) is a switching waveform figure in the case of the prototype of the coil structure of FIG. FIG. 10 is a cross-sectional view for explaining another configuration example of the coil structure according to the third embodiment. (A), (b), (c) and (d) are expanded sectional views which show the modification of the interlinkage conductor part in FIG. FIG. 5 is a schematic diagram of an automobile that is an application example of a reactor according to any of Embodiments 1 to 3.

1st form which concerns on this indication is provided with the magnetic body core, the coil, and the interlinkage conductor part which is a short circuit conductor which comprises a closed circuit, a magnetic body core has a core leg, and a coil is around a core leg. The main magnetic flux is generated in the core leg by the current flowing through the coil, the interlinkage conductor part is arranged at a position in contact with the core leg and interlinkage with the main magnetic flux, and the coil and the interlinkage conductor part are electrically connected to each other. Insulated coil structure.

According to this embodiment, since the interlinkage conductor part cancels the main magnetic flux generated from the coil, the generation of a surge voltage can be suppressed.

In the second embodiment according to the present disclosure, in the first embodiment, the interlinkage conductor portion includes a first interlinkage conductor portion and a second interlinkage conductor portion, and the first interlinkage conductor portion is provided above the coil, The second interlinkage conductor portion is provided below the coil.

According to this embodiment, the main magnetic flux generated from the coil is further canceled by the two interlinkage conductor portions of the first interlinkage conductor portion and the second interlinkage conductor portion. Therefore, surge can be further suppressed.

In the third embodiment according to the present disclosure, in the first or second embodiment, the interlinkage conductor portion is arranged to be wound around the outer side of the core leg.

In the fourth form according to the present disclosure, in the first or second form, the interlinkage conductor part is partially embedded in the surface of the core leg.

Hereinafter, embodiments will be described with reference to the drawings.

(Embodiment 1)
1 (a) to 1 (c) are schematic diagrams for explaining the configuration of the reactor according to the first embodiment, and FIG. 1 (a) is a perspective view for illustrating the overall configuration, and FIG. FIG. 1B is a front view when viewed from the axial direction of the coil, and FIG. 1C is a cross-sectional view taken along line AA.

In the present embodiment, a configuration of a so-called outer iron type reactor in which a coil 102 is formed as a winding, for example, in order to apply a magnetic flux to a so-called E-shaped magnetic core 101 is shown as an example.

The coil 102 is connected to the switching circuit, and 0 V and the maximum voltage are alternately applied to the coil 102 according to the switching operation. At that time, magnetic flux is generated by the current flowing through the coil 102. As the magnetic core 101, a magnetic body having a relative permeability larger than 1 may be used. The magnetic flux generated by the coil 102 mainly flows in the magnetic core 101. An annular interlinking conductor 103 is arranged so as to interlink with the magnetic flux generated in the magnetic core 101. As shown in FIGS. 1 (a) to 1 (c), the interlinkage conductor 103 may be a single conductor or a conductive wire wound two or more times. Further, the interlinkage conductor portion 103 may be formed of a covered conductor. An induced electromotive force is generated in the interlinkage conductor 103 in accordance with a change in magnetic flux generated in the magnetic core 101, and as a result, an induced current flowing in the interlinkage conductor 103 is controlled by the induction current controller 104. Therefore, both ends of the interlinkage conductor portion 103 and both ends of the induced current control portion 104 are connected so that they can be electrically connected in a ring shape.

2 (a) to 2 (d) are schematic structural diagrams for explaining the configuration of the reactor of the comparative example. The only difference from the reactor of the first embodiment is that the interlinkage conductor 103 and the induced current controller 104 are not provided.

The basic operation when the reactor is used as a switching power supply will be described using the circuit shown in FIG. 3A as an example. The switching circuit shown in FIG. 3A includes a reactor L, a semiconductor switch S, a diode D, and a capacitor C.

When the reactor L in FIG. 3A is the reactor of the comparative example, in the so-called off operation in which the reactor voltage is maximized from zero by the switching operation of the circuit, or in the so-called on operation in which the reactor voltage is maximized to zero When the charge accumulated in the capacitance components of the capacitor C and the semiconductor switch S in the circuit is repeatedly discharged, for example, the terminal voltage of the diode D generates a large surge as shown in FIG. Due to the influence of the inductance component of the magnetic component such as the reactor L, a back electromotive force is generated that prevents the charge in the circuit from being discharged / charged. Therefore, a surge is generated particularly during a transient such as switching on / off. It is.

Here, the operation of the interlinkage conductor 103 and the induced current controller 104, which are the main components in the present disclosure, will be described with the results of a comparative experiment using simulation.

FIG. 4 is a structural diagram for explaining a magnetic field simulation model of a reactor of a comparative example. In the simulation of the comparative example, a magnetic flux distribution generated in the magnetic core 101 by the magnetomotive force of the current flowing through the coil 102 is used using a model for so-called two-dimensional analysis whose analysis target is the cross-sectional shape of the reactor as shown in FIG. Simulation analysis. The analysis region is set as shown in FIG. 4 from the shape symmetry of the analysis target.

FIG. 5 is a structural diagram for explaining the magnetic field simulation model of the reactor according to the first embodiment. In the simulation of the first embodiment, a model for two-dimensional analysis is also used, and the analysis region is set as shown in FIG. 5 from the shape symmetry of the analysis target. In this simulation, the induced current control unit 104 is approximated as a conductor assuming that the induced current flowing through the interlinkage conductor portion 103 always flows, and the interlinkage conductor portion 103 in FIG. 5 is represented by two cross sections. Modeling is conducted under the condition that conduction is conducted.

6 (a) and 6 (b) are comparison diagrams of magnetic flux distributions by magnetic field simulation between the reactor of the comparative example and the reactor of the first embodiment. In this comparison result, the power condition applied to the coil 102 is set to be the same magnetomotive force in both results, and the magnetic flux distribution at the moment when the current flowing through the coil 102 is maximized is the same from the calculation result of the magnetic vector potential. The magnetic flux distribution is displayed under conditions. In both the reactor of the comparative example and the reactor of the first embodiment, most of the magnetic flux flows through the magnetic core 101. However, in the reactor of the first embodiment, the interlinkage conductor is affected by the induced current flowing through the interlinkage conductor 103. It can be seen that the magnetic flux is slightly distributed so as to leak from the core so as to go around the lower section of the portion 103. This indicates a decrease in inductance of the reactor itself, and this decrease in inductance appears remarkably at the time of transient during switching operation. Further, the change in the magnetic flux distribution in the gap portion of the central leg that is the main magnetic flux path of the magnetic core 101 is small, and the magnetic flux interlinking with the coil 102 is rather less in the reactor of the first embodiment. It can be said that the copper loss by itself is slightly reduced.

FIG. 7 is a circuit diagram for explaining a coupled simulation model of reactor magnetic field analysis and circuit analysis. The circuit simulation and the coupled analysis are performed by substituting the reactor of the comparative example and the reactor of the first embodiment for the reactor L in FIG. The circuit itself is assumed to have a simple configuration in order to observe the surge phenomenon of the reactor L, and the voltage Vi of the input power supply approximates a rectangular wave having a voltage value of 500 V, a period of 10 μs, and a duty ratio of 50%, and has the circuit configuration shown in FIG. The output voltage Vo is observed by simulation.

FIG. 8A and FIG. 8B are comparison diagrams of switching voltage waveforms obtained by a coupled simulation of magnetic field analysis and circuit analysis between the reactor of the comparative example and the reactor of the first embodiment. As shown in FIG. 8A, it can be seen that the reactor of the comparative example generates a large surge voltage during the switching operation, and further pulsates the voltage, thereby causing electromagnetic noise in the circuit. On the other hand, as shown in FIG. 8B, it can be seen that the reactor of the first embodiment has a small surge voltage during the switching operation and a small voltage pulsation. As described above, the present disclosure has an effect of suppressing the generation of surge and the electromagnetic noise in the switching power supply circuit having the reactor.

As can be seen from the result of the magnetic field simulation, it is effective to install the interlinkage conductor 103 and the induced current controller 104 so as to interlink with the magnetic flux generated in the magnetic core 101. Embodiment 1 As another configuration, the interlinkage conductor 103 and the induced current control unit 104 may be installed at a location where the amount of interlinkage magnetic flux increases.

A configuration as shown in a schematic diagram for explaining another configuration example of the reactor of the first embodiment shown in FIGS. 9A to 9C is also possible. Specifically, the interlinkage conductor 103 and the induced current controller 104 are arranged at the center leg portion of the magnetic core 101. The installation location of the interlinkage conductor 103 and the induced current controller 104 can be designed based on the surge suppression effect and the so-called magnetic circuit structure mainly composed of the magnetic core 101.

Although the reactor magnetic core 101 of the first embodiment has been shown as an example of a so-called outer iron type reactor using a core called a so-called E-shaped core, the so-called inner core using a so-called U-shaped core is shown. It can also be applied to the structure of a reactor called an iron type.

10 (a) to 10 (g) show detailed examples of the induced current control unit 104 in FIG. 1 or FIG. The induced current control unit 104 in FIG. 10A is a simple conductor that short-circuits both ends of the interlinkage conductor 103. The induced current control unit 104 in FIG. 10B is a capacitive element connected between both ends of the interlinkage conductor unit 103. The induced current control unit 104 in FIG. 10C is a resistance element connected between both ends of the interlinkage conductor unit 103. The induced current control unit 104 in FIG. 10D is a series circuit of a capacitive element and a resistive element connected between both ends of the interlinkage conductor 103. The induced current control unit 104 in FIG. 10 (e) is a variable capacitance element connected between both ends of the interlinkage conductor unit 103. The induced current control unit 104 in FIG. 10F is a variable resistance element connected between both ends of the interlinkage conductor unit 103. The induced current control unit 104 in FIG. 10G is a series circuit of a variable capacitance element and a variable resistance element connected between both ends of the interlinkage conductor portion 103.

As described above, the induction current control unit 104 can be realized by an electric element such as a capacitive element or a resistance element in addition to the conductor that short-circuits both ends of the interlinkage conductor part 103. When the induction current control unit 104 is made of an electric element, the energization performance of the induction current control unit 104 has a certain frequency characteristic depending on the impedance value of the interlinkage conductor unit 103 and the impedance value of the induction current control unit 104. As a result, the surge suppression effect can have frequency characteristics.

(Embodiment 2)
FIG. 11 is a schematic diagram for explaining the power supply circuit according to the second embodiment. In FIG. 11, the same components as those in FIGS. 1A to 1C used for describing the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The power supply circuit according to the second embodiment includes the reactor according to the present embodiment and the main circuit 107, and is configured so that the main circuit unit 107 of the power supply and the coil 102 are connected to each other by the wiring 108 that follows the coil of the reactor. Have The reactor according to the second embodiment is the same as the reactor according to the first embodiment. And an operation control unit 106 that receives detection data from the characteristic detection unit 105 as an input. The operation control unit 106 provides control data to the induced current control unit 104. The induced current control unit 104 has a switch that operates based on the control data from the operation control unit 106, and the conduction of the induced current is turned on and off by this switch.

According to this configuration, the operation state of the power supply circuit using the reactor of the present embodiment is detected, and the induced current control unit 104 controls the induced current flowing through the interlinkage conductor unit 103 based on the detection result. Thus, the surge suppression effect of the reactor can be made variable.

12 (a) to 12 (g) show detailed examples of the induced current control unit 104 in FIG. As a switch used in the induced current control unit 104, a semiconductor switch, a mechanical switch, or the like can be used.

In the above description, the coil 102 is composed of a winding, but a planar coil may be used.

(Embodiment 3)
FIG. 13 is a cross-sectional view for explaining a configuration example of the coil structure according to the third embodiment. The coil structure according to the third embodiment includes a magnetic core 101, a coil 102, and

interlinkage conductor portions

103a and 103b, which are short-circuit conductors that constitute a closed circuit. The magnetic core 101 has a core leg 110, and the coil 102 is disposed around the core leg 110. A main magnetic flux is generated in the core leg 110 by the current flowing through the coil 102. The

interlinkage conductor portions

103a and 103b are arranged in contact with the core leg 110 and at a position interlinking with the main magnetic flux. The coil 102 and the

interlinkage conductor portions

103a and 103b are electrically insulated from each other.

In the coil structure of FIG. 13, the interlinkage conductor portion includes a first interlinkage conductor portion 103a and a second interlinkage conductor portion 103b. The first interlinkage conductor portion 103 a is provided above the coil 102. The second interlinkage conductor portion 103 b is provided below the coil 102.

The coil structure of the third embodiment is configured such that the

interlinkage conductor portions

103a and 103b are linked to the main magnetic flux, and the induced current due to the counter electromotive force generated by the alternating magnetic flux is maximized. However, the number of interlinkage conductor portions is not limited to two, and may be one or three or more.

According to this configuration, there is an effect that the

interlinkage conductor portions

103a and 103b cancel the main magnetic flux generated from the coil 102. Therefore, generation of surge voltage can be suppressed.

FIG. 14A is a circuit diagram for explaining an example of the switching operation when the coil structure of FIG. 13 is used as a reactor, and FIG. 14B shows a diode terminal in the case of the reactor of the comparative example. It is a wave form diagram which shows that a big surge voltage generate | occur | produces.

14A includes a reactor L, a semiconductor switch S, a diode D, and a capacitor C. When the reactor L in FIG. 14A is the reactor of the comparative example, a large surge voltage is generated at both ends of the diode D as shown in FIG.

15A is a switching waveform diagram in the case of the reactor of the comparative example, and FIG. 15B is a switching waveform diagram in the case of the prototype of the coil structure of FIG. It turns out that generation | occurrence | production of a surge voltage can be suppressed by using the coil structure of FIG.

FIG. 16 is a cross-sectional view for explaining another configuration example of the coil structure according to the third embodiment. The coil structure of Embodiment 3 may be configured as a transformer including a primary coil 102a and a secondary coil 102b as shown in FIG.

17 (a) to 17 (d) are enlarged cross-sectional views showing modifications of the interlinkage conductor portion 103a in FIG. As shown in FIG. 17A, the interlinkage conductor portion 103 a may be disposed so as to be wound around the core leg 110. As shown in FIG. 17 (b), the interlinkage conductor portion 103 a may be partially embedded in the surface of the core leg 110. As shown in FIG. 17C, the entire interlinkage conductor portion 103 a may be embedded in the core leg 110. As shown in FIG. 17D, the interlinkage conductor portion 103 a may be a flat conductor, or the entire interlinkage conductor portion 103 a may be embedded in the core leg 110. .

Here, the modification example of the first interlinkage conductor portion 103a in FIG. 16 has been described, but the same modification can be made to the second interlinkage conductor portion 103b in FIG. The same applies to the first interlinkage conductor portion 103a and / or the second interlinkage conductor portion 103b in FIG.

(Application examples)
FIG. 18 is a schematic diagram of an automobile as an application example of the reactor according to any one of the first to third embodiments. An automobile 201 illustrated in FIG. 18 includes a battery 202 and a charger 203. Charger 203 has the reactor of any one of the first to third embodiments. The surge suppression effect of the present disclosure can suppress malfunction of the charge control microcomputer and electromagnetic noise to the surrounding environment.

The coil structure according to the present disclosure has an effect of suppressing surge voltage and surge current generated in a switching power supply using a reactor. Therefore, by using the coil structure according to the present disclosure, it is not necessary to employ an element having excessive resistance to cope with the destruction of the circuit caused by the surge phenomenon, and the cost of the entire power supply circuit can be reduced. . In addition, since it has an effect of suppressing electromagnetic noise caused by the surge phenomenon, it is possible to reduce costs by reducing noise countermeasure components.

DESCRIPTION OF SYMBOLS 101 Magnetic core 102,102a, 102b Coil 103,103a, 103b Linkage conductor part 104 Inductive current control part 105 Operation characteristic detection part 106 Operation control part 107 Main circuit part 108 Reactor coil wiring 110 Core leg 201 Car 202 Battery 203 Charger

Claims

A magnetic core;
Coils,
The interlinkage conductor portion that is a short-circuit conductor constituting a closed circuit,
The magnetic core has a core leg,
The coil is disposed around the core leg;
Due to the current flowing in the coil, a main magnetic flux is generated in the core leg,
The interlinkage conductor portion is disposed at a position in contact with the core leg and interlinkage with the main magnetic flux,
A coil structure in which the coil and the interlinkage conductor are electrically insulated from each other.
The coil structure according to claim 1,
The interlinkage conductor portion includes a first interlinkage conductor portion and a second interlinkage conductor portion,
The first interlinkage conductor portion is provided above the coil,
The second interlinkage conductor part is a coil structure provided below the coil.
In the coil structure according to claim 1 or 2,
The interlinkage conductor portion is a coil structure disposed so as to be wound around the outer side of the core leg.
In the coil structure according to claim 1 or 2,
The interlaced conductor portion is a coil structure that is arranged partially embedded in the surface of the core leg.