JP2015204407A - Winding element for noise reduction and inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a winding element for noise reduction capable of improving productivity by reducing the impact on the signal component of normal mode, even if two strip conductors are superposed and wound into pancake, and to provide an inverter device including the same.SOLUTION: A winding element 10A for noise reduction includes a coil 2 having first and second coil parts 2a, 2b laminated in the axial direction, and a core 1 for passing magnetic flux generated in the coil 2 and housing the coil 2. The first coil part 2a is formed by wounding and shaping one part of two first and second strip conductors 21, 22 in the longitudinal direction having a thickness equal to or less than a skin depth corresponding to the use frequency like pancake while arranging the second conductor 22 on one side of the first conductor 21 in the thickness direction while sandwiching an insulating layer, and arranging the remaining part of the second coil part 2b in the longitudinal direction thereof on the other side of the first conductor 21 in the thickness direction while sandwiching an insulating layer.

Description

  The present invention relates to a noise reduction winding element that is used in order to reduce predetermined noise, and particularly to reduce high-frequency noise, and an inverter device including the noise reduction winding element.

  Conventionally, a common mode choke coil is known as an element for reducing or eliminating common mode noise. This common mode choke coil is generally a winding element that includes one core and two windings (coils) and functions as an inductor for a common mode current, but does not function as an inductor for a differential mode current. is there. Such a common mode choke coil is used, for example, in a power supply line or an interface circuit using a differential signal such as a USB as a countermeasure against radiated electromagnetic noise.

  One specific example is a common mode choke coil used in a so-called power conditioner of a solar cell power generation system. This solar cell power generation system includes, for example, a solar cell module that converts solar light energy into electric power, and a power conditioner that converts DC power generated by the solar cell module into AC power for system linkage. And a distribution board that distributes the AC power converted by the power conditioner to various places in the house and to the electric power company. For conversion to AC power, a high-frequency (switching frequency of about 20 kHz or more) inverter is used from the viewpoint of noise prevention. The high-frequency current is smoothed by an LC filter into a sine wave current, and then passed through a common mode choke coil. , Output to the outside (home electrical equipment). A common mode choke coil is also applied to the power input portion from the solar cell to the power conditioner. These common mode choke coils reduce common mode noise flowing in a path formed from the solar cell module, power conditioner and domestic electrical equipment and their ground wires, thereby reducing or preventing radiated electromagnetic noise.

  As such a common mode choke coil, there is a noise reduction winding element disclosed in Patent Document 1, for example. The noise reduction winding element disclosed in Patent Document 1 is a noise reduction winding element for reducing high-frequency noise, and passes a coil, a magnetic flux generated by the coil, and houses the coil. The coil is configured by winding a strip-shaped conductor member such that the width direction of the conductor member is along the axial direction of the coil. In such a noise reduction winding element, the inner surface of the core facing the coil is made parallel to the end surface of the coil viewed from the axial direction, so that the AC magnetic flux lines leaking into the coil can be reduced in the width direction of the strip-shaped conductor. As a result, the AC loss can be reduced by effectively suppressing the eddy current generated in the conductor.

JP 2013-33924 A

  By the way, in the noise reduction winding element disclosed in Patent Document 1, the coil is so-called pancake winding. When two strip-like conductors of this coil are overlapped and pancake-wound, the amount of magnetic flux passing through the two conductors is different, so that there is a difference in the inductance values of the two coils composed of the two conductors. For this reason, when this is used for a common mode choke coil, an imbalance of inductance occurs between the two coils, and as a result, it acts as a normal mode choke coil, and a normal mode signal that originally does not require attenuation. It will affect the ingredients.

  In the noise reduction winding element disclosed in Patent Document 1, the coil has a single pancake winding, and the core has a pod type structure that wraps the single pancake winding coil. For this reason, in order to extract the lead wire from the end of the innermost strip conductor in the coil of the single pancake winding to the outside of the core and from the through hole diameter of the minimum diameter that does not disturb the magnetic flux line, There was a need for an unproductive process that was difficult to automate, such as folding the edge part at a right angle and folding it multiple times.

  The present invention is an invention made in view of the above-mentioned circumstances, and its purpose is to reduce the influence on the signal component of the normal mode even when two strip-shaped conductors are stacked and pancake-wrapped, and the productivity is reduced. It is providing the coil element for noise reduction which can improve. And this invention is providing an inverter apparatus provided with this winding element for noise reduction.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, a noise reduction winding element according to an aspect of the present invention is a noise reduction winding element for reducing high-frequency noise, and passes a coil and a magnetic flux generated by the coil. A core portion that houses the first and second coil portions stacked in the axial direction, and the first coil portion is arranged in the longitudinal direction of the two strip-shaped first and second conductors. The second coil portion is formed by winding one portion in a pancake shape with the second conductor disposed on one surface side in the thickness direction of the first conductor with an insulating layer interposed therebetween. Winding the remaining portions in the longitudinal direction of the first and second conductors in a pancake shape with the second conductor disposed on the other surface side in the thickness direction of the first conductor across an insulating layer Formed by round molding Is, the first and second conductors, respectively, characterized in that it is a skin depth or less of thickness corresponding to the use frequency.

  Such a noise reduction winding element has two windings of a first conductor and a second conductor, so that, for example, the number of turns is one in comparison with a coil in which one conductor is formed into one single pancake winding having the same diameter. However, the number of turns of the entire coil is invariable by forming the first coil portion and the second coil portion in a so-called double pancake winding so as to be doubled in series. On the other hand, the conductor cross-sectional area is also halved by forming a double pancake winding compared to the single single pancake winding coil described above, but it is doubled by two parallel stacks and remains unchanged. Therefore, under the constraint condition of the same size and shape, the noise reduction winding element is a double pancake winding of two layers of the first and second conductors, so that the number of turns of the entire coil and the conductor cross-sectional area are unchanged. On the other hand, both end portions of the first and second conductors can be positioned on the outermost periphery of the double pancake winding, and the opening is simplified as compared with the single pancake winding. For this reason, in single pancake winding, the end of the strip-shaped conductor is folded at right angles and folded several times, which makes it difficult to automate the above-mentioned inferior productivity step, and the above-described noise-reducing winding element improves productivity. it can. And since the said winding element for noise reduction makes double pancake winding, since the arrangement | positioning of the thickness direction of the 1st and 2nd conductors laminated | stacked on the axial direction is reversed, the said coil by the 1st conductor up and down And each induced electromotive force generated in each of the coils by the second conductor cancels out, eddy current can be effectively suppressed, and the inductance values of the coil by the first conductor and the coil by the second conductor can be balanced. it can. Further, in such a noise reduction winding element, since the first and second conductors each have a thickness equal to or less than the skin depth, the eddy current generated in each of the first and second conductors can be more effectively suppressed. Therefore, such a noise reduction winding element can reduce the influence on the signal component of the normal mode even if two strip-shaped conductors are overlapped and pancake-wrapped, thereby improving productivity.

  In another aspect, the noise reduction winding element further includes a disk-shaped magnetic member between the first coil portion and the second coil portion.

  For example, when the width of the conductor is increased, distortion that makes the magnetic flux lines non-parallel to the axial direction tends to occur inside the coil. Therefore, the noise reduction winding element further includes a disk-shaped magnetic member disposed between the first coil portion and the second coil portion, so that the magnetic flux lines on the outer diameter side in the axial direction can be provided. The straightness can be recovered, and the occurrence of distortion in which the magnetic flux lines are not parallel to the axial direction can be suppressed. As a result, for example, if the coil diameter is increased, the overall diameter increases and the diameter of the core occupying the majority of the weight increases. As a result, weight reduction is impeded, so the conductor is expanded in the width direction where weight does not increase easily. Thus, the noise reduction winding element can increase the coil cross-sectional area and can be reduced in weight.

  In another aspect, in the above-described noise reduction winding element, the magnetic member has a thickness t and a gap s between the outer peripheral end of the magnetic member and the inner peripheral surface of the core portion. It is formed so as to satisfy the condition of ≧ t.

  For example, if the outer peripheral end of the magnetic member and the inner peripheral surface of the core part are too close, it becomes easy to generate a strain in which the magnetic flux lines are not parallel to the axial direction in the vicinity thereof. Therefore, the noise reduction winding element can more effectively suppress the occurrence of the distortion in the magnetic flux lines by forming the magnetic member so as to satisfy the condition of s ≧ t.

  In another aspect, in the above-described noise reduction winding element, the core portion and the magnetic member are insulating film-coated metal powders, and are compacted by pressurizing and solidifying ferromagnetic metal powders. It is characterized by comprising.

  In such a noise reduction winding element, since the green compact is isotropic and has a large specific resistance, eddy current loss generated in the core portion and the magnetic member can be suppressed.

  According to another aspect, in the above-described noise reduction winding element, the magnetic member is a band-shaped soft magnetic material having a thickness equal to or less than the skin depth corresponding to the operating frequency, with the second insulating layer interposed therebetween. It is a wound iron core wound and formed into a pancake shape.

  In such a noise reduction winding element, the soft magnetic material used for the wound iron core is a ferromagnetic metal, and examples thereof include pure iron, iron-based alloys, and amorphous materials. In comparison, since the anisotropy in the width direction of the conductor and the magnetic permeability are several to several hundred times larger, the generation of the strain in the magnetic flux lines can be further suppressed and the thickness can be reduced (light weight). In addition, since such a noise reduction winding element has a large specific resistance across the second insulating layer, eddy current loss in the disk can be minimized.

  Further, in another aspect, the above-described noise reduction winding element further includes a cylindrical pole piece disposed at a substantially central portion of the core portion, and the core portion includes the substantially central portion. A hole for receiving the pole piece in the portion, and the pole piece is disposed in the hole so that a gap can be formed between an inner periphery of the hole in the core portion and an outer periphery of the pole piece. It is characterized by.

  The air gap of the magnetic circuit is a circle surrounding the pole piece. In this case, due to the assembly error of the pole piece, there can be a portion where the gap is narrowed and a portion where the gap is widened. On the other hand, it becomes much more forgiving (inductance values are stabilized against variations in assembly errors). In addition, since the change in inductance causes a magnetic attractive force as it is, the vibration accompanying the change in the gap due to AC excitation does not essentially occur in the above-described noise reduction winding element.

  In another aspect, in the above-described noise reduction winding element, the core part and the pole piece are made of an insulating film-coated metal powder and pressed from a ferromagnetic metal powder. The density of the pole piece is higher than the density of the core part.

  Such a winding element for noise reduction is formed by forming a pole piece in which magnetic flux lines are concentrated and the magnetic flux density is higher than that of the core part, using a material having a higher magnetic permeability than the core part, that is, a material having a higher density. , Leakage magnetic flux lines to the coil can be reduced, and eddy current loss in the first and second conductors of the coil can be suppressed.

  According to another aspect, in the above-described noise reduction winding element, the core portion includes a plurality of divided cores divided in the circumferential direction.

  In such a noise reduction winding element, the split core makes it easy to assemble the coil mounted on the core portion, and also allows the coil heat to escape directly to the outside. In addition, in such a noise reduction winding element, it is possible to visually check the coil abnormality after assembly or operation.

  An inverter device according to an aspect of the present invention includes an inverter unit that converts DC power into AC power, and a common mode choke coil that is disposed on at least one of the input side and the output side of the inverter unit, The common mode choke coil is any one of the above-described noise reduction winding elements.

  According to this, an inverter device using any one of the above-described noise reduction winding elements as a common mode choke coil can be provided.

  The noise-reducing winding element according to the present invention can reduce the influence on the signal component of the normal mode even when two strip-shaped conductors are overlapped and pancake-wrapped, thereby improving productivity. And according to this invention, the inverter apparatus using such a winding element for noise reduction can be provided.

It is a circuit diagram which shows the electrical structure of the power conditioner apparatus using the coil | winding element for noise reduction of embodiment, and an inverter apparatus. It is sectional drawing which shows the structure of the winding element for noise reduction of the 1st aspect used for the said power conditioner apparatus. It is a schematic diagram of the coil used for the winding element for noise reduction of the first aspect. It is the graph which represented the skin depth (skin thickness) of various metal materials as a function of frequency. It is explanatory drawing before winding the 1st conductor and 2nd conductor which are used for the coil element for noise reduction of the said 1st aspect around a winding frame. It is explanatory drawing of the state which started winding the 1st conductor and the 2nd conductor in the winding method in the manufacturing method of the coil used for the winding element for noise reduction of the said 1st aspect. It is explanatory drawing of the state in the middle of winding the said 1st conductor and the said 2nd conductor around a winding frame. FIG. 3 is a perspective view of a state where the first conductor and the second conductor have been wound and formed on a winding frame. It is a perspective view of the state where the coil which formed the 1st and 2nd conductor by double pancake winding was stored in the core part. It is a figure which shows the equivalent circuit of the coil used for the said winding element for noise reduction. It is a figure which shows the equivalent circuit of the coil of a comparative example. It is a principal part expanded sectional view of the winding element for noise reduction of the said 1st aspect showing the magnetic flux diagram of the magnetic member used for the winding element for noise reduction of the said 1st aspect. It is a principal part expanded sectional view of the winding element for noise reduction of the said 1st aspect showing the magnetic flux diagram of the magnetic member of other embodiment. It is a principal part expanded sectional view of the winding element for noise reduction of the said 1st aspect showing the magnetic flux diagram in the case of not providing a magnetic member. It is sectional drawing of the winding element for noise reduction of the 2nd aspect in embodiment. It is sectional drawing of the winding element for noise reduction of the 3rd aspect in embodiment. It is sectional drawing of the coil | winding element for noise reduction of the 4th aspect in embodiment. It is sectional drawing of the coil | winding element for noise reduction of the 5th aspect in embodiment.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably. Further, in this specification, when referring generically, it is indicated by a reference symbol without a suffix, and when referring to an individual configuration, it is indicated by a reference symbol with a suffix.

  FIG. 1 is a circuit diagram illustrating an electrical configuration of a power conditioner device using the noise reduction winding element and the inverter device according to the embodiment. The power conditioner device PC in the present embodiment is a device that controls the power supplied to the load device LD. The power conditioner device PC controls the power supplied to the load device LD by controlling, for example, the voltage and frequency of the power supplied from the power source PV. Such a power conditioner device PC includes, for example, common mode choke coils CL1 and CL2, capacitors C1 to C3 and C6 to C8, a converter unit CV, an inverter unit IV, and a normal mode as shown in FIG. And a choke coil CL3.

  As the power source PV, a commercial power source, a power source obtained by converting the commercial power source into a direct current, a battery such as a primary battery or a secondary battery, and various power sources such as a solar battery can be used. In the example shown in FIG. 1, a solar cell is used as the power source PV.

  The common mode choke coils CL1 and CL2 are choke coils used for reducing or removing common mode noise, respectively. The common mode choke coil CL1 is used to reduce common mode noise from the power conditioner device PC to the power source PV, and is disposed on the input side of the power conditioner device PC. In the example shown in FIG. 1, the common mode choke coil CL1 is disposed so as to be interposed between the power source PV and the converter unit CV, and the input end of the common mode choke coil CL1 is the input end of the power conditioner device PC. And the positive and negative polarities are matched and connected to the power source PV. The common mode choke coil CL2 is used to reduce common mode noise from the power conditioner device PC toward the load device LD, and is disposed on the output side of the power conditioner device PC. In the example shown in FIG. 1, the common mode choke coil CL2 is disposed so as to be interposed between the inverter unit IV and the load device LD. Each of these common mode choke coils CL1 and CL2 includes two coil portions and a core portion that passes the magnetic flux generated by the two coil portions and accommodates the two coils. Each of these common mode choke coils CL1 and CL2 coils will be described more specifically later.

  The output terminal of the common mode choke coil CL1 is connected to the converter unit CV via capacitors C1 to C3. More specifically, the output terminal of the common mode choke coil CL1 is connected between the two capacitors C1 and C2 connected in series with each other and a capacitor C3 made of an electrolytic capacitor. And it is connected to the input terminal of the converter unit CV with a negative polarity. A series circuit composed of two capacitors C1 and C2 and a capacitor C3 are connected in parallel.

  The converter unit CV is a device that boosts or lowers the voltage of the power supplied from the power source PV via the common mode choke coil CL1 and the capacitors C1 to C3. The converter unit CV includes, for example, a so-called chopper type that includes a boosting reactor (winding element, coil) L, a switching element Tr1, a freewheeling diode (freewheel diode) D1, a diode D6, and capacitors C4 and C5. It is a DC-DC converter circuit. The switching element Tr1 is a power transistor element such as an insulated gate bipolar transistor (IGBT) element or a power MOSFET element. Here, a high-power IGBT element is used as the switching element Tr1.

  One end of the boosting reactor RL is connected to the plus end of the input end of the converter unit CV, and the other end of the boosting reactor is connected to the anode terminal of the diode D6 and the collector terminal of the IGBT element Tr1. The collector terminal of the IGBT element Tr1 is connected to the negative end of the input end of the converter unit CV. The gate terminal of the IGBT element Tr1 is connected to a converter control circuit (not shown) that controls the on / off timing of the IGBT element Tr1. In addition, a free-wheeling diode D1 is connected in parallel between the collector terminal and the emitter terminal of the IGBT element Tr1. That is, the cathode terminal of the reflux diode D1 is connected to the collector terminal of the IGBT element Tr1, and the anode terminal of the reflux diode D1 is connected to the emitter terminal of the IGBT element Tr1. Thus, the direction of the free-wheeling diode D1 is connected in the opposite direction to the input / output direction of the IGBT element Tr1. The series connection circuit of the diode D6 and the switching element Tr1 is connected in parallel to both ends of the parallel connection circuit of the capacitor C4 and the electrolytic capacitor C5 connected in parallel to each other.

  In such a converter unit CV, when the switching element Tr1 is turned on, energy from the power source PV is accumulated in the boosting reactor RL, and when the switching element Tr1 is turned off, energy accumulated in the boosting reactor RL is released. As a result, the voltage of the boosting reactor RL is added to the voltage of the power source PV to convert the voltage level, and the voltage is output while being smoothed by the capacitor C4 and the electrolytic capacitor C5 connected in parallel via the diode D6. Both ends of the parallel connection circuit of the capacitor C4 and the electrolytic capacitor C5 are the output ends of the converter unit CV.

  The inverter unit IV is a device that converts DC power into AC power. The input end of the inverter unit IV is connected to the output end of the converter unit CV, that is, both ends in the parallel connection circuit of the capacitor C4 and the electrolytic capacitor C5. The inverter unit IV includes, for example, a plurality of switching elements and a plurality of free-wheeling diodes connected to each of the plurality of switching elements.

  In the present embodiment, for example, four switching elements Tr2 to Tr5 and the same number of four free-wheeling diodes D2 to D5 as the switching elements Tr2 to Tr5 are provided to supply one-phase AC power to the load device LD. ing. More specifically, the switching elements Tr2 to Tr5 are power transistor elements such as IGBT elements and power MOSFET elements, for example, similarly to the switching element Tr1, and here, the high power IGBT element is the switching element Tr2. ~ Tr5 is used.

  The IGBT element Tr2 and the IGBT element Tr3 are connected in series by connecting the emitter terminal of the IGBT element Tr2 to the collector terminal of the IGBT element Tr3, and constitute a pair of switching units. Similarly, the IGBT element Tr4 and the IGBT element Tr5 are connected in series by connecting the emitter terminal of the IGBT element Tr4 to the collector terminal of the IGBT element Tr5, and constitute a pair of switching units. The gate terminals of the IGBT elements Tr2 to Tr5 are connected to an inverter control circuit (not shown) that controls the on / off timing of the IGBT elements Tr2 to Tr5. The free-wheeling diodes D2 to D5 are connected in parallel to the IGBT elements Tr2 to Tr6, respectively, with the anode terminal connected to the emitter terminal and the cathode terminal connected to the collector terminal. That is, these free-wheeling diodes D2 to D5 are connected in directions opposite to the input / output directions of the IGBT elements Tr2 to Tr5.

  The series connection circuit of the IGBT element Tr2 and the IGBT element Tr3 and the series connection circuit of the IGBT element Tr4 and the IGBT element Tr5 are connected in parallel to each other, and further, the output terminal of the converter unit CV, that is, the capacitor C4 and The electrolytic capacitor C5 is connected to both ends of the parallel connection circuit. In other words, the collector terminals of the IGBT element Tr2 and the IGBT element Tr4 are connected to one end of the capacitors C4 and C5, and the emitter terminals of the IGBT element Tr3 and the IGBT element Tr5 are connected to the other end of the capacitors C4 and C5. It is connected.

  The inverter IV having such a configuration converts DC power into AC power by turning on and off the IGBT elements Tr2 to Tr5 at appropriate timings under the control of the inverter control circuit (not shown). Then, from each connection point of each series connection circuit, that is, from each connection point between the IGBT element Tr2 and the IGBT element Tr3 and each connection point between the IGBT element Tr4 and the IGBT element Tr5, the AC of the inverter IV Electric power is output.

  The output terminal of the inverter unit IV is connected to the load device LD via a normal mode choke coil CL3, a capacitor C6, a common mode choke coil CL2, and capacitors C7 and C8. More specifically, the output terminal of the inverter unit IV is connected to the input terminal of the normal mode choke coil CL3, and the output terminal of the normal mode choke coil CL3 is connected to the input terminal of the common mode choke coil CL2. A capacitor C6 is connected in parallel between the output terminal of the normal mode choke coil CL3 and the input terminal of the common mode choke coil CL2. That is. The capacitor C6 is connected between both ends at the input end of the normal mode choke coil CL3 and is connected between both ends at the input end of the common mode choke coil CL2. The output terminal of the common mode choke coil CL2 is connected between both ends thereof by a series circuit including two capacitors C7 and C8 connected in series with each other and connected to the load device LD.

  The ground line of the solar cell PV, the ground line of the power conditioner device PC, and the ground line of the load device LD are grounded. The ground line of the power conditioner device PC has a connection point (input side ground point) between the capacitors C1 and C2 connected in series with each other, and a connection point (output side connection) between the capacitors C7 and C8 connected in series with each other. Point) and each.

  Next, the noise reduction winding element will be described more specifically below. As the common mode choke coils CL1 and CL2 of the above-described power conditioner device PC, the following noise reduction winding elements 10A to 10E of the first to fifth modes are used. Hereinafter, it demonstrates in order.

  FIG. 2 is a cross-sectional view showing the configuration of the first embodiment of the noise reduction winding element used in the power conditioner device. FIG. 3 is a schematic view of a coil used in the noise reduction winding element of the first aspect. FIG. 4 is a graph showing the skin depth (skin thickness) of various metal materials as a function of frequency. The horizontal axis in FIG. 4 is the frequency expressed in kHz, and the vertical axis is the skin depth (skin thickness) expressed in mm. FIG. 5 is an explanatory diagram before winding a first conductor and a second conductor used in the noise reduction winding element of the first aspect around a winding frame. FIG. 6 is an explanatory diagram of a state in which the first conductor and the second conductor are started to be wound around a winding frame in the method of manufacturing a coil used in the noise reduction winding element of the first aspect. FIG. 7 is an explanatory diagram of a state in the middle of winding the first conductor and the second conductor around a winding frame. FIG. 8 is a perspective view of a state in which the first conductor and the second conductor are wound and formed on a winding frame. FIG. 9 is a perspective view of a state in which a coil in which the first and second conductors are formed by double pancake winding is housed in a core portion.

  As shown in FIG. 2, the noise reduction winding element 10 </ b> A of the first aspect includes a core part 1, a coil 2 included in the core part 1, and a magnetic member 3.

  The core portion 1 is a member that houses the coil 2 through the magnetic flux generated in the coil 2 when the coil 2 is energized. In this embodiment, as shown in FIG. 2, the core portion 1 is a so-called pot type including a coil 2, and the core portion 1 includes two first and second core members 1 a facing each other in the axial direction. 1b.

  In this embodiment, the first and second core members 1a and 1b have the same shape from the viewpoint of improving productivity, and the first and second core members 1a and 1b are respectively in the axial direction of the coil 2. The disk-shaped disk part 11 which covers the edge part of this, and the cylindrical part 12 extended substantially perpendicularly from the outer periphery of the disk part 11 are provided.

  The first and second core members 1a and 1b are made of a material having predetermined magnetic characteristics. In this embodiment, the first and second core members 1a and 1b are made of a green compact (compact core) obtained by pressurizing and solidifying an insulating film-coated metal powder. The metal powder used for the green compact is a soft magnetic powder and a ferromagnetic metal powder. Examples of the metal powder include pure iron powder, iron-based alloy powder (for example, Fe—Al alloy, Fe—Si alloy, Sendust, Permalloy, etc.), or amorphous powder. Further, as an insulating film covering the surface of the soft magnetic powder, a film made of an inorganic material such as an oxide, a film made of an organic material such as a silicone resin, and a composite film made up of two layers of an inorganic material and an organic material Etc. are formed.

  The first and second core members 1a and 1b can control the magnetic properties based on the particle size and particle size distribution of the powder and the density of the molded body. For example, the magnetic permeability can be increased by increasing the density of the molded body. It is possible to suppress eddy current loss by reducing the particle size of the powder. For this reason, in order to realize the electromagnetic characteristics required for the noise reduction winding element 10A, the particle size of the powder used for the green compact, the density of the molded body, and the like are adjusted. In the case of pure iron powder, the density of the compact can be adjusted by adding the nonmagnetic powder material in the range of about 3.0 g / cc to about 5.0 g / cc, and about 5.0 g / cc to about 7.7 g. In the range of / cc, the pressure can be adjusted by molding.

  And the cylindrical part 12 of the 1st core member 1a and the cylindrical part 12 of the 2nd core member 1b are match | combined so that it may mutually contact | abut on those end surfaces, and thereby the core part 1 which has the coil accommodating part 13 inside is formed. The

  An opening opened to the cylindrical portion 12 of the first core member 1a and the cylindrical portion 12 of the second core member 1b so as to penetrate from the coil storage portion 13 to the outside at a predetermined depth from the end face of the cylindrical portion 12, respectively. A hole 14 is provided.

  The coil 2 includes a first coil portion 2a and a second coil portion 2b stacked on one axial side (the upper side in FIG. 1) of the first coil portion 2a.

  The first coil portion 2a and the second coil portion 2b are formed by two first and second conductors 21 and 22 each having a predetermined width and a long strip shape (tape shape or ribbon shape) in one direction. Yes.

In this embodiment, the first conductor 21 and the second conductor 22 have the same configuration, and are made of aluminum having a predetermined thickness that is insulated and coated with an insulating material. The thickness of each of the first conductor 21 and the second conductor 22 (thickness of aluminum in this example) is equal to or less than the skin depth (skin thickness) with respect to the use frequency (drive frequency) fed to the noise reduction winding element 10A. Thickness, which can further reduce the eddy current loss. In general, the current flowing through the coil flows only in the range up to the skin depth, and the current does not flow uniformly throughout the conductor cross section. Therefore, eddy current loss can be reduced by setting the thicknesses of the first and second conductors 21 and 22 to be less than the skin depth. The skin depth δ is generally δ = (ρ / πfμ) ^1/2 (where f: frequency, μ: magnetic permeability of the conductor member, ρ: electrical conductivity of the conductor member). FIG. 4 is a graph showing the skin depth δ of various metal materials as a function of frequency.

  As shown in FIG. 3, each of the first conductor 21 and the second conductor 22 has a first coil forming portion 21a, 22a as one part in the longitudinal direction of the strip, and a second coil as the other part in the longitudinal direction. The portions between the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b are connected portions 21c and 22c.

  The first coil forming portions 21a and 22a are wound in a pancake shape to form the first coil portion 2a. The 2nd coil formation parts 21b and 22b are wound by pancake shape, and form the 2nd coil part 2b. The width and length of the second coil forming portions 21b and 22b are substantially the same as those of the first coil forming portions 21a and 22a.

  The connecting portions 21c and 22c connect the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b. In this embodiment, the connecting portions 21c and 22c have a width so as to form a predetermined angle α with respect to the longitudinal direction (XX direction) of the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b. It is bent in the direction (Y-Y direction) and extends from the first coil forming portions 21a, 22a to the second coil forming portions 21b, 22b. The connecting portions 21c and 22c have the same width as the first coil forming portions 21a and 22a.

  Therefore, the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b are separated from each other by a predetermined distance L2 in the width direction (YY direction). The distance L2 is larger than the width L1 of the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b.

  The first conductor 21 and the second conductor 22 are wound into a pancake shape as follows to form a first coil portion 2a and a second coil portion 2b.

  More specifically, as shown in FIG. 5, first, the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b of the first conductor 21 and the second conductor 22, respectively, are temporarily wound. It is wound around a bobbin 51. Note that the winding directions of the first coil forming portions 21a and 22a and the second coil forming portions 21b and 22b around the temporary winding bobbin 51 are opposite to each other.

  The connecting portion 21c of the first conductor 21 is fixed so as to be applied to the cylindrical winding frame 52 from behind, while the connecting portion 22c of the second conductor 22 is applied to the winding frame 52 from the front side. It is fixed so as to be removed. That is, the connecting portion 21 c of the first conductor 21 and the connecting portion 22 c of the second conductor 22 are fixed to the winding frame 52 so as to face each other in a cross shape via the winding frame 52.

  As shown in FIGS. 6 and 7, the first coil of the second conductor 22 with insulation coating is formed on one surface 25a in the thickness direction of the first coil forming portion 21a of the first conductor 21 with insulation coating. The first coil forming portion 21a of the first conductor 21 and the first coil forming portion 22a of the second conductor 22 are unwound from the temporary winding bobbin 51 in a state where the portions 22a are arranged so as to overlap each other in the radial direction. It is wound around the reel 52 in the shape of a pancake in the clockwise direction in the figure. Accordingly, the first portions 21a and 22a in the longitudinal direction of the two strip-shaped first and second conductors 21 and 22 are secondly arranged on one surface side in the thickness direction of the first conductor 21 (21a) with the insulating layer interposed therebetween. A pancake-shaped first coil portion 2a is formed by being wound into a pancake shape with the conductor 22 (22a) being disposed.

  Similarly, the second coil formation of the second conductor 22 is performed in a state where the second coil formation portion 22b of the second conductor 22 is disposed on the other surface 25b side in the thickness direction of the second coil formation portion 21b of the first conductor 21. Each of the portion 22b and the second coil forming portion 21a of the first conductor 21 is wound around the winding frame 52 in a counterclockwise direction in the figure in a pancake shape while being unwound from the temporary winding bobbin 51. Thereby, the remaining portions 21b and 22b in the longitudinal direction of the first and second conductors 21 and 22 are arranged on the other surface side in the thickness direction of the first conductor 21 (21b) with the insulating layer interposed therebetween. ) Is disposed, and a pancake-like second coil portion 2b is formed by being wound into a pancake-like shape.

  As a result, as shown in FIG. 8, a pancake-like second coil portion 2 b is formed on one axial side of the first coil portion 2 a (upper side in FIG. 8), and a double pancake coil 2 is obtained. It is done.

  The end ends of the first coil forming portions 21a and 22a forming the first coil portion 2a are bent outward in the radial direction to form first coil portion lead portions 21d and 22d. End ends of the second coil forming portions 21b and 22b forming the coil portion 2b are bent outward in the radial direction to form second coil portion lead portions 21e and 22e.

  These lead portions 21d, 22d; 21e, 22e need only be bent once outward in the radial direction, and can be easily manufactured. The folding may be performed after the entire amount has been wound. For example, the provisional winding bobbin 51 is provided with a slit for forming the lead portion in advance, and the first coil forming portion is provided in the slit for forming the lead portion. The end ends of 21a and 22a and the second coil forming portions 21b and 22b may be inserted and bent first. This is more preferable because the length of the lead-out portion and the accuracy of the bending amount are stabilized.

  As shown in FIG. 9, when the first core member 1a and the second core member 1b are combined with each other, the coil 2 formed in the double pancake winding is formed in the lead hole 14 of the first core member 1a. The second coil portion lead portions 21e and 22e are housed in the coil housing portion 13 so that the first coil portion lead portions 21d and 22d can be inserted into the lead hole 14 of the second core member 1b, respectively. .

  Next, returning to FIG. 2, the magnetic member 3 will be described. The magnetic member 3 is a member for suppressing distortion that is not parallel to the axial direction of the magnetic flux lines, and the magnetic member 3 of this embodiment is a disk-shaped magnetic member made of the same material as the core portion 1. It is composed of More specifically, the magnetic member 3 is made of a green compact that is an insulating film-coated metal powder and is formed by pressing and hardening a ferromagnetic metal powder.

  The magnetic member 3 is disposed between the first coil portion 2a and the second coil portion 2b. The magnetic member 3 is preferably formed so that its thickness t is the same as or smaller than the gap s between the outer peripheral surface (outer peripheral end) of the magnetic member 3 and the inner peripheral surface of the core part ( s ≧ t).

  The noise reduction winding element 10A of the first aspect having such a configuration has two single conductors 21 and 22 overlapping each other, for example, one conductor having one single pancake having the same diameter. The number of turns is halved compared to a coil formed into a winding, but by forming a so-called double pancake winding in which the first coil portion 2a and the second coil portion 2b are formed, it is doubled in series. The number of turns of the entire coil 2 remains unchanged. On the other hand, the conductor cross-sectional area is also halved by forming a double pancake winding compared to the single single pancake winding coil described above, but it is doubled by two parallel stacks and remains unchanged. Therefore, under the constraint condition of the same size and shape, the noise reduction winding element 10A of the first aspect is a double pancake winding of the first and second conductors 21 and 22, and the entire coil 2 is thus wound. The end portions 21d, 21e; 22d, 22e of the first and second conductors 21, 22 can be positioned on the outermost periphery of the double pancake winding, while making the number of turns and the conductor cross-sectional area unchanged. Compared to this, it is easier to speak. For this reason, in the single pancake winding, the process of poor productivity, which is difficult to automate, such as folding the end portion of the belt-like conductor at a right angle and folding it in a plurality of times, becomes unnecessary, and the noise reduction winding element 10A of the first aspect is , Improve productivity. In addition, in the noise reduction winding element 10A of the first aspect, the first and second conductors 21 and 22 and the core are collected by gathering both end portions of the first and second conductors 21 and 22 on the outer periphery of the core portion 1. The joint surface of the inner wall surface of the part 1 can be simplified, a thinner and better thermal contact is possible, and the heat dissipation is remarkably improved.

  FIG. 10 is a diagram showing an equivalent circuit of a coil used in the noise reduction winding element. FIG. 11 is a diagram illustrating an equivalent circuit of a coil of a comparative example. For example, when the second conductor 22 is arranged on one surface side in the thickness direction of the first conductor 21 and the first coil portion and the second coil portion are wound, the first conductor as shown in FIG. There is a possibility that an AC leakage magnetic flux line q2 that penetrates an area of a finite area formed by the second conductor 22 and the second conductor 22 (a portion indicated by hatching in FIG. 11) generates the induced electromotive force p3.

  On the other hand, the noise reduction winding element 10A of the first aspect has a double pancake winding, and the arrangement of the first and second conductors 21 and 22 in the thickness direction is reversed up and down stacked in the axial direction. . For this reason, as shown in FIG. 10, the induced electromotive force p1 generated in the first conductor 21 and the second conductor 22 of the first coil portion 2a and the first conductor 21 and the second conductor 22 of the second coil portion 2b. The generated induced electromotive force p2 is canceled out, eddy current is effectively suppressed, eddy loss can be suppressed, and the inductance values of the coil by the first conductor 21 and the coil by the second conductor 22 can be balanced.

  Furthermore, as described above, the first and second conductors 21 and 22 of the noise reduction winding element 10A according to the first aspect have a thickness equal to or less than the skin depth. The eddy current generated in each of the 22 can be more effectively suppressed.

  Further, since the noise reduction winding element 10A of the first aspect does not have an electrical connection portion between one of the lead portions 21d and 22d and the other lead portions 21e and 22e, so-called room temperature superconductivity This is a suitable structure when the first and second conductors 21 and 22 are formed of a material.

  As described above, the noise reduction winding element 10A according to the first aspect configured as described above has an influence on the signal component in the normal mode even when the two strip-shaped conductors 21 and 22 are overlapped and pancake-wrapped. Can be reduced and productivity can be improved. And this embodiment can provide the inverter part IV and power conditioner apparatus PC which used the winding element 10A for noise reduction of such a 1st aspect. Therefore, since the inverter unit IV and the power conditioner device PC in the present embodiment use the noise reduction winding element 10A of the first aspect, the influence on the signal component in the normal mode can be reduced and the productivity can be improved. .

  FIG. 12 is an enlarged cross-sectional view of a main part of the noise reduction winding element of the first aspect, showing a magnetic flux diagram of a magnetic member used in the noise reduction winding element of the first aspect. For example, when the width of the conductor is increased, distortion that makes the magnetic flux lines non-parallel to the axial direction tends to occur inside the coil. For this reason, the winding element 10A for noise reduction of the first aspect includes the disk-shaped magnetic member 3 disposed between the first coil part 2a and the second coil part 2b, so that the outer diameter side The magnetic flux lines can recover straightness in the axial direction, and the occurrence of distortion in which the magnetic flux lines are not parallel to the axial direction can be suppressed. As a result, for example, if the coil diameter is increased, the overall diameter increases and the diameter of the core occupying the majority of the weight increases. As a result, weight reduction is impeded, so the conductor is expanded in the width direction where weight does not increase easily. Thus, the noise reduction winding element can increase the coil cross-sectional area and can be reduced in weight.

  Further, for example, if the outer peripheral end of the magnetic member and the inner peripheral surface of the core part are too close to each other, a strain in which the magnetic flux lines are not parallel to the axial direction is likely to be generated in the vicinity thereof. For this reason, the noise reduction winding element 10A according to the first aspect is formed so that the thickness t of the magnetic member 3 is the same as or smaller than the gap s as described above, and is shown in FIG. As described above, the magnetic member 3 increases the effect of maintaining the linearity of the magnetic flux line q on the outer diameter side of the coil 2 in the axial direction, and more effectively generates distortion that is not parallel to the axial direction of the magnetic flux line q. Can be suppressed.

  In the noise reduction winding element 10A of the first aspect described above, the core portion 1 and the magnetic member 3 are made of the green compact. For this reason, in the noise reduction winding element 10A of the first aspect, since the green compact is isotropic and has a large specific resistance, eddy current loss generated in the core portion and the magnetic member can be suppressed.

  FIG. 13 is an enlarged cross-sectional view of a main part of the winding element for noise reduction according to the first aspect, showing a magnetic flux diagram of a magnetic member according to another embodiment. FIG. 14 is an enlarged cross-sectional view of a main part of the noise reduction winding element of the first aspect, showing a magnetic flux diagram when no magnetic member is provided. In the above description, the magnetic member 3 is formed such that the thickness t is the same as or smaller than the gap s between the outer peripheral surface of the magnetic member 3 and the inner peripheral surface of the core part (s ≧ t). However, the present invention is not limited to this form and can be changed as appropriate. For example, as shown in FIG. 13, the magnetic member 203 is formed such that the thickness t is larger than the gap s between the outer peripheral surface of the magnetic member 203 and the inner peripheral surface of the core portion 1 (s <t). May be. In this case, the magnetic flux lines q are distorted as compared with the case of the condition of s ≧ t as in the above embodiment, but the magnetic flux lines on the outer diameter side of the coil 2 than in the case shown in FIG. q distortion can be suppressed.

  FIG. 15 is a cross-sectional view of the noise reduction winding element of the second aspect in the embodiment. Moreover, in the noise reduction winding element 10A of the first aspect, the magnetic member 3 is provided. However, for example, as shown in FIG. 15, the magnetic member 3 may not be provided (the second aspect of the second aspect). Winding element 10B for noise reduction). In this case, for example, when the first conductor 121 and the second conductor 122 constituting the coil 2 are made of copper, the specific resistance of copper (1.68 μΩcm) is smaller than the specific resistance of aluminum (2.65 μΩcm). Therefore, in the case of the same DC resistance, the width L2 of the first conductor 121 and the second conductor 122 can be made narrower than the width L1 (shown in FIG. 1) of the one formed of aluminum. Therefore, even when it does not have the magnetic member 3, it is preferable at the point which can suppress the distortion of the magnetic flux line of an outer diameter side.

  However, when the first conductor 121 and the second conductor 122 are made of copper instead of aluminum and have the same DC resistance, the noise reduction winding element 10B according to the second aspect is heavier than that made of aluminum. Becomes larger, making it difficult to meet the demand for weight reduction such as in-vehicle use. Therefore, as described above, the noise reduction winding element 10 </ b> A according to the first aspect has a configuration in which the coil 2 is formed by the wide first conductor 21 and the second conductor 22 made of aluminum and includes the magnetic member 3. It is preferable because the weight can be reduced to suppress the distortion of the magnetic flux lines.

  FIG. 16 is a cross-sectional view of a third aspect of the noise reduction winding element according to the embodiment. In the noise reduction winding element 10 </ b> A of the first aspect, the magnetic member 3 is formed of a green compact. For example, as shown in FIG. 16, the magnetic member 303 is formed from a wound iron core obtained by winding a strip-shaped soft magnetic body 303a having a thickness equal to or less than the skin depth corresponding to the operating frequency into a pancake shape with the second insulating layer interposed therebetween. The noise reduction winding element 10C of the third aspect may be configured. The soft magnetic body 303a used for the wound core is a ferromagnetic metal, and examples thereof include pure iron, iron-based alloy, and amorphous. Such a noise reduction winding element 10C of the third aspect has anisotropy in the width direction of the coil and a magnetic permeability several tens to hundred times larger than the isotropic magnetic green compact. The effect of suppressing the distortion of the wire is great and can be made thin (light). Further, since the noise reduction winding element 10C of the third aspect has a large specific resistance across the second insulating layer, the eddy current loss in the disk can be minimized.

  FIG. 17 is a cross-sectional view of the noise reduction winding element of the fourth aspect in the embodiment. In the noise-reducing winding element 10A of the first aspect, the core portion 1 is configured by a columnar member that does not have a hole in the center portion. However, the present invention is not limited to this configuration, and can be changed as appropriate. For example, as shown in FIG. 17, the core part 401 is comprised by the cylindrical member which has the hole 401a in the center part, The column-shaped pole piece 406 may be arrange | positioned in the hole 401a ( Winding element 10D for noise reduction of the fourth aspect).

  More specifically, the pole piece 406 is, for example, a cylindrical body made of a green compact (compact core) obtained by pressing and hardening an insulating film-coated metal powder. The metal powder used for the green compact is a soft magnetic powder and a ferromagnetic metal powder. Examples of the metal powder include pure iron powder, iron-based alloy powder (for example, Fe—Al alloy, Fe—Si alloy, Sendust, Permalloy, etc.) or amorphous powder as described above.

  The pole piece 406 has an outer diameter smaller than the inner diameter of the hole 401a of the core portion 401, and is formed so that a gap 407 is formed between the outer peripheral surface of the pole piece 406 and the inner peripheral surface of the hole 401a of the core portion 401. Has been.

  In this way, when a coaxial structure is provided in which the pole piece 406 is disposed at the center of the core 401, the magnetic circuit gap 407 has a circular shape surrounding the pole piece 406. In this case, the gap piece 407 narrows and widens due to the assembly error of the pole piece 406. However, in the noise reduction winding element of the fourth aspect, the contribution to the inductance cancels out, so that the variation in inductance Is much more tolerant of assembly accuracy (inductance values are stabilized against variations in assembly errors). Since the change in the inductance causes a magnetic attraction force as it is, the vibration accompanying the change in the air gap due to the AC excitation does not essentially occur.

  Further, in that case, the pole piece 406 in which the magnetic flux lines are concentrated and the magnetic flux density is higher than that of the core portion 401 is preferably formed of a material having a higher magnetic permeability than the core portion 401, that is, a material having a high density. . Thereby, the leakage magnetic flux line to the coil 2 can be reduced, and the eddy current loss in the first and second conductors 21 and 22 of the coil 2 can be suppressed.

  FIG. 18 is a cross-sectional view of the noise reduction winding element of the fifth aspect in the embodiment. In the noise reduction winding element 10A of the first aspect, the core portion 1 is composed of the first and second core members 1a and 1b having the disk portions. However, the present invention is not limited to this configuration and can be changed as appropriate. . For example, as shown in FIG. 18, the core unit 501 may be composed of a plurality of divided cores 501a (divided into two in the example shown in FIG. 18) divided in the circumferential direction (noise of the fifth aspect). Reduction winding element 10E). With this configuration, it is easy to assemble the coil 2 to the core portion 501, and the heat generated by the coil 2 can be directly radiated to the outside. It is also possible to visually check the abnormality of the coil 2 after assembly or during operation.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

PC power conditioner devices CL1, CL2 Common mode choke coil IV Inverter device 1 Core portion 2 Coil 2a First coil portion 2b Second coil portion 3 Magnetic member 21 First conductor 22 Second conductor

Claims (9)

A noise reduction winding element for reducing high frequency noise,
Coils,
A magnetic flux generated by the coil is passed, and a core portion that houses the coil is provided,
The coil includes first and second coil portions stacked in the axial direction,
In the first coil portion, the second conductor is disposed on one side in the thickness direction of the first conductor, with one portion in the longitudinal direction of the two strip-shaped first and second conductors sandwiching an insulating layer. Formed by winding into a pancake shape
In the second coil portion, the remaining portion in the longitudinal direction of the first and second conductors is in a state where the second conductor is disposed on the other surface side in the thickness direction of the first conductor with an insulating layer interposed therebetween. Formed by winding into a pancake shape,
Each of the first and second conductors has a thickness equal to or less than a skin depth corresponding to a use frequency. The noise reduction winding element according to claim 1, further comprising a disk-shaped magnetic member between the first coil part and the second coil part. The magnetic member is formed so that a thickness t thereof and a gap s between an outer peripheral end of the magnetic member and an inner peripheral surface of the core portion satisfy a condition of s ≧ t. Item 2. A noise reduction winding element according to Item 2. 4. The noise reduction according to claim 2, wherein the core part and the magnetic member are made of a green compact, which is an insulating film-coated metal powder and is made by pressing and hardening a ferromagnetic metal powder. 5. Winding element. The magnetic member is a wound iron core obtained by winding a band-shaped soft magnetic material having a thickness equal to or less than a skin depth corresponding to the operating frequency into a pancake shape with a second insulating layer interposed therebetween. The noise reduction winding element according to any one of claims 2 to 4. A cylindrical pole piece disposed in a substantially central part of the core part, further comprising:
The core portion includes a hole for receiving the pole piece in the substantially central portion;
The said pole piece is arrange | positioned in the said hole so that a clearance gap can be formed between the inner periphery of the hole in the said core part, and the outer periphery of the said pole piece. 6. The noise reduction winding element according to claim 5. The core part and the pole piece are formed of a green compact obtained by pressurizing and solidifying a ferromagnetic metal powder, which is an insulating film-coated metal powder,
The noise reduction winding element according to claim 6, wherein a density of the pole piece is higher than a density of the core portion. The noise reduction winding element according to any one of claims 1 to 7, wherein the core portion includes a plurality of divided cores divided in a circumferential direction. An inverter that converts DC power to AC power;
A common mode choke coil disposed on at least one of the input side and the output side in the inverter unit,
The inverter device according to claim 1, wherein the common mode choke coil is the noise reduction winding element according to claim 1.