FI120067B - A method of making an inductive component and an inductive component - Google Patents

Description

METHOD FOR MANUFACTURING THE INDUCTIVE COMPONENT AND THE INDUCTIVE COMPONENT

A method for manufacturing an inductive component and a modular inductive component as well as a filter and a filter family.

Inductive components, inductors and transformers, are used to store energy (choke) and transfer it across galvanic separation (transformer) using a magnetic field. The inductive components consist of a coil and a core, which may be one or more and which are in direct contact with each other. The voltage applied to the winding causes a changing magnetic field in the heart, in which it is possible to store energy. This voltage applied to the windings induces the voltage to the windings itself (self-induction) and to any other so-called secondary windings connected to the same core, thus transferring energy from the primary to the secondary. The core material of the inductive components is e.g. transformer iron plates, iron powder, ferrite and amorphous metals. The coil of inductive components is used e.g. copper wire, aluminum wire, circuit board, foils. In addition, inductive components may be combined with other types of components, such as resistors and capacitors, as well as switch components, to provide, for example, filters, i.e. filters. Filters are used in electrical engineering. for filtering electrical energy, ie components of different frequencies are removed or left unchanged. Examples of such filters are e.g. so-called 1) harmonics chokes, which filter the form of the mains current, 2) sinusoidal filters, in which the pulse-width modulated frequency converter signal and the high frequency component signal are filtered to sinusoidal 2, are filtered more slowly, as well as a number of other filters which may be combinations of the above.

Today, inductive components and filters are designed and manufactured individually for each application and current value. Thus, for example, designing a 1 to 1000A filter family takes considerable time. In addition, the production logistics is complicated to organize, as there are many different titles in production, where 2 separate components are needed for each different filter. Thus, it is difficult to control the production process of both low current and high current (i.e. bulky) inductive components simultaneously. In addition, the high current (e.g. 1000A) inductive component is large because the surface area required for cooling is proportional to the total loss and the allowable loss power density (loss per volume) of the large component is lower than that of the small component. The power density and power loss values used as component design parameters must then be calculated, which increases the size, cost, and weight of the component. In addition, the high frequency or so-called AC resistance of the winding of a large (e.g. 1000A) inductive component is high because high current requires a large conductor and at high frequencies only uses a surface layer of conductors, thus increasing the effective resistance of the thick conductor. For example, Sintermetal Prometheous and Micrometals make chokes based on Sintermetal material, but they are bulky single chokes and no high-current choke is available or requires extra large-size chucks.

Occasionally, individual E-shaped cores are successively placed in a kind of modular structure. However, this one has a coil of non-optimal shape.

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With lower wattages, for example in switching power supplies, several inductive components can be mounted on a circuit board in parallel, as a kind of module. In this case, for example, by dividing a large transformer into several small transformers, the overall height of the device can be reduced. However, this solution is limited to low power, mainly to switching power supplies (typically <5kW).

Also known is U.S. Patent No. 7,111,665, which discloses modular inductive components. However, the solution according to the US patent differs from the solution according to the application, for example, in that in the assembly step of the modules, the adjacent parts are not connected to one another by their cores but by their enclosures around the core. In this case, the adjacent / overlapping packets rest on the sides, covers or bottoms of their housings, but the cores themselves do not rest on each other. The solution of the present application is superior to the solution of 3 US patents, e.g. in the solution according to the application, it is possible to completely omit the bulky, weight and cost-increasing casing, since the shape and construction of the core is such that the cores can be mechanically attached directly to one another. Similarly, cooling according to the application is better than the US solution.

Generally speaking, the available power electronics filters do not well meet the miniaturization and compression efficiency requirements prevailing in electronics.

The object of the present invention is to improve the manufacture of inductive components and filters comprising them and to improve the compactness of such filters. The method according to the invention is characterized by what is stated in the characterizing part of claim 1, and the modular inductive component according to the invention is characterized by what is described in the characterizing part of claim 4. Other embodiments of the invention are characterized by what is set forth in the other claims.

The method according to the invention enables efficient and flexible manufacture of 20 different inductive components and compact filters consisting of them. It is possible to make production logistics simple. In addition, various additional features can be easily customized to the products. In addition, the manufacturing process according to the method is easy to automate.

In a preferred embodiment, the inductive component and the filter formed therefrom are manufactured by parallel and / or series connection of smaller inductive components, so-called modules. In this case, only the module needs to be optimized at the design stage and the product family itself is created by scaling quickly. Likewise, there will be logistical benefits in production as the number of titles decreases. The core 30 of these modules is made of a so-called Sintermetal material, which, due to its good mechanical properties, can also be used as a mechanics or part of the mechanics of an inductive component and a filter consisting of such. Modules can be designed and manufactured eg. various fastening structures or parts of the fastening structure, whereby the modules can be mechanically connected to one another using fasteners integrated into the module cores.

In another embodiment, some modules also include electronics, whereby a compact power electronic converter can be manufactured by the method.

In a third embodiment, the electronics are integrated within the inductive basic modules.

The invention will now be described in more detail with reference to the accompanying drawings, in which:

Fig. 1 is a drawing symbol for a choke, which has two terminals and a heart, 15

Figure 2 is a filter drawing symbol with a choke, a capacitor, and an input and output port,

Figure 3 is a three-phase filter with chokes and capacitors,

Fig. 4 is a power electronic converter with a filter inlet and a filter at the output, with the output filter having connections to the plus and minus terminals of the converter intermediate circuit;

Figure 5 is a graph of the input / output voltage of a du / dt filter and a graph of the input and output voltage of a sinusoidal filter,

Figure 6 shows a 3-phase choke with coils and a common core,

Figure 7 shows a 3-phase choke with windings wound on separate cores, 30 5

Fig. 8 illustrates a choke having a toggle terminal and an output terminal consisting of one or more modules and a terminal connection and a mechanic connection. In Fig. 9, the modules are arranged in a three-dimensional configuration,

In Figure 10, there is a cooling gap between the modules,

In Figure 11, among the modules is a cooling module, 10

Fig. 12 shows an illustrative rotational symmetric section of a module consisting of a coil, a core and an insulator,

Figure 13 is a single-phase core with a center pin and a set of edge pins and mounting holes,

Figure 14 shows a 3-phase core with pin and mounting hole,

Figure 15 shows the coil, insulating half and core half, 20

Fig. 16 is an assembly of a module having an insulating member bracket, a module assembly connected by insulating member brackets, and a modular choke having a connector and a capacitor. Fig. 17 is a modular structure having a mounting element and

Figure 18 shows a Sintermetal core consisting of several pieces with a fastening element.

Figure 1 shows a drawing symbol for the simplest inductive component, the inductor. The inductor 1, or inductance, consists of a coil having two terminals, i.e. terminals 2 and 3. Mostly, the inductor 1 also has a core 4 consisting of a magnetic material such as ferrite or iron. The inductor stores energy in its magnetic field and this energy can be added or removed. More complex inductive components, such as transformers, may have multiple windings, allowing energy to be transferred between the terminals of the various windings. The present invention also encompasses such more complex inductive components. 5 Often the heart 4 is not drawn on the drawing symbol.

Nk. it is possible to provide a filter 5 e.g. by connecting the inductor 6 to the capacitor 7 as shown in Figure 2. As such, it is possible, for example, to prevent high frequency interference from propagating from input port 8 to output port 9.

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In power electronics, especially at higher power levels (e.g.> 10kW), it is typical to use a three-phase system. The filter 10 of the three-phase system consists of the chokes 11 and capacitors 12 of each phase. In Figure 3, the capacitors 12 are coupled to a so-called star coupling, but could be in some other 15 coupling, such as a triangle coupling. Further, the number of filter steps could be other than 1 or 3. The capacitors 12 of Figure 3 may physically consist of a plurality of separate capacitors.

Figure 4 illustrates a power electronic converter 18 coupled to input 14 via filter 15 and output 16 through filter 17. The converter could be, for example, a rectifier, inverter or frequency converter, whereby input 14 would be a mains supply and output 16 would be connected via cable to an electric motor. Alternatively, input 14 could be connected to a generator and output 16 could be connected to a power grid. The filter 17 of the output 16 is connected via capacitors 25 to the plus terminal 18 and minus terminal 19 of the converter 13, whereby energy can be efficiently transferred between the input 14, the output 16 and the converter 13 in an optimal manner. In addition, electromagnetic interference can be effectively suppressed. The connections of Figure 4 are exemplary. Filters can be configured in many different ways, depending on the application. In addition, the connections from the filter 17 30 to the + and - terminals 18, 19 of the converter 13 can be made by other means than the capacitor. Similarly, the converter 13 could also be a 1-phase.

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Figure 5 shows examples of curved shapes filtered in motor applications. The so-called du / dt filter moderates the rate of rise of the input voltage 20 (typically 5kV / us) to a slower output voltage 21 (typically 1kV / us). Such filtering will reduce motor overvoltages and hence insulation damage and bearing failure and long motor cables. In another example, the pulse width modulated input voltage 22 is filtered to a sinusoidal output voltage 23. The efficiency of the motor is thereby improved and the interfering sound level is reduced. In addition to these applications, harmonic current filtering may be mentioned. In addition, such filters can be coupled together, for example, as a so-called LCL filter, which transmits energy to the power grid via a frequency converter 10. The throttle stages of the LCL filter may consist of single or three-stage throttles. In addition to the filters described above, the invention can also be applied to the manufacture of transformers, for example, if the output voltage of the drive is to be raised to a higher level.

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Figure 6 shows an embodiment of a 3-phase choke 24. Here, the three windings 25 of the choke are wound to a common, three-pole core 26. Thus, the 3-phase choke produces a mechanically solid structure. Further, the structure can take advantage of the feature of the 3-phase system that the sum of the functional currents 20 is zero, whereby the total amount of core material decreases as the magnetic flux of each winding can pass through the other two windings and no own flow path is required for each winding. Correspondingly, the problem with this structure is that it has no significant inductance against non-functional, so-called parasitic, disturbance currents, which would also often be filtered.

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Figure 7 shows another embodiment of a 3-phase choke 27. Here, each phase is wound 28 to its own core 29. This option requires slightly more cardiac material, since each phase has its own magnetic flux path. However, such an arrangement also provides considerable attenuation against non-functional or parasitic interference currents.

The choke 30 of Figure 8 is assembled by connecting smaller choke modules 31 together. In its simplest form, this can be accomplished by interconnecting the input terminals 32 of the parallel modules 8 and, respectively, connecting the output terminals 33 to one another using any suitable coupling method 36 such as soldering, screwing, riveting, or other commonly known method. Likewise, the mechanics of the choke modules 31 are interconnected 35 using any suitable method. In this way, a suitable choke can be designed and manufactured quickly for different current values, using for example tested and optimized basic modules. There may be one or more of these basic modules in the inductor.

Figure 9 shows a three-dimensional arrangement 37 of six modules 39. Modules 10 could be interconnected in several ways. For example, all modules could be electrically connected in parallel to provide one high current module. The other extreme would be to leave the modules electrically disconnected, resulting in a configuration with 6 low-current chokes. In practice, a more likely connection could be to always connect two modules electrically in parallel to provide a three-to-15-phase choke.

Thus, it is essential that the core mechanics of the individual modules also constitute the mechanics of the modular inductive component. In other words, the assembly process consists of mechanical interconnection of all modules and electronic interconnection of modules appropriate for electrical operation. Such an assembly process is efficient and flexible. Alternatively, the assembly may be performed in stages by first assembling and possibly testing all modules required by the modular choke, and then by modular choke assembly 25, or by physically assembling the modules as the modular choke assembly advances.

The modular structure also has other advantages. For example, since the current of a single module is less than the current of the entire modular choke, it is possible to design the winding wire used in the module 30 relatively thin relative to the total winding surface of the parallel-connected modules. This reduces the high frequency or AC resistance of the windings, which reduces losses.

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In addition, the module can be configured for different voltages (% of Unom) eg by connecting the coil parts in parallel or in series. This can be used eg when configuring a module for 400VAC or 690VAC.

The filter stages of a multi-stage filter, such as an LCL filter, can be integrated into a single mechanical entity by the method of the invention.

Furthermore, since it is possible to leave cooling slots 41 between modules 40, i.e. small gaps in suitable locations for air circulation, the total cooling area of a choke 10 can be significantly larger than a corresponding conventional choke, respectively, allowing higher current and loss power densities to provide a more affordable filter.

Another option to enhance cooling is to use in the assembly, as shown in Figure 11, special cooling modules 43 among modules 42, which may include, for example, liquid, sheet or phase change cooling. However, cooling structures, such as liquid cooling ducts, could also be integrated directly into the duct modules. For example, various cooling structures such as fins and liquid cooling ducts can be designed for the modules.

In addition to or instead of the cooling module 43, the module to be added to the modules 42 could also be a capacitor module or an electronics module, in particular a module containing power electronic circuits.

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Figure 12 shows a rotationally symmetrical sectional section 44 of the module consisting of a core 46 (or portions of the core), a winding 45, and an insulator 47. The dielectric may be in the winding, in the core, or may be a separate part, such as a coil body, or more than one of these. The module may further include brackets to hold it together and connect it to other modules, filter parts, or external parts. For example, the core halves are held together by means of claw clips on the insulating coil body, or alternatively, the core halves are pressed together using a bolt (s) or by some other commonly known method such as lacquering, gluing, pressing or welding.

It is efficient to use so-called Sintermetal material as the heart material. It is based on 5 pressed and sintered metal powders. The Sintermetal material can be pressed into the desired shape and the shapes produced can be very detailed, for example integrating power electronics, cooling fins and liquid cooling into the module. In this case, the choke / inductive component itself acts as a cooling element. Another alternative core material is iron powder consisting of pu-10 crosslinked magnetic powder.

Figure 13 shows a preferred form of the module core 48. The module has a square design which makes the modular choke compact. However, the center pin 49 of the module is circular, which again is an optimal form for winding resistance and minimizing winding loss. The geometric shapes may be other than those mentioned above. The edge pins 50 leave the coil visible, which improves cooling. The edge pins 50 also have a fastening hole 51. Thus, the module core includes passages for mechanical fastening, whereby, for example, using a threaded rod, the module cores can be tightly clamped (screwed) by nuts. Such a structure 20 reinforces itself. The coils can be connected to each other, for example, by using fastening rods for carrying current. Modules can be assembled and secured using, for example, yoke pins and nuts, other fasteners, gluing or welding.

25 The core geometry of the module can be optimized for the Sintermetal process. For example, its surface area and height may be optimal for the process. In addition, the core of the module may consist of several different magnetic materials. For example, it is possible to use high saturation flux and low loss, possibly more expensive material such as amorphous iron 30 and other Sintermetal material at the so-called mid-point of the heart due to its good mechanical properties. Such a so-called "composite core" is better in price / performance than a single material core.

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Figure 14 illustrates a 3-phase module core 52. The pins 53 in the core 52 are circular and have mounting holes 54 in the structure. The completed modules can be subsequently retrofitted to a desired configuration such as a 1-phase or 3-phase.

Parts of the heart may be half as in Figures 13 and 14, or subparts of half as quarters. In addition, the heart may consist of sectorial slices. By interconnecting overlapping portions of the heart, a solid structure is achieved. Leaving a small gap between the slices can improve air circulation and cooling. In addition, the module core halves may consist of various overlapping projections, thereby reducing the compression surface area required in the Sintermetal process. On the other hand, it is possible to design the surface of the module core half so that different air gaps are obtained between the module core halves during the assembly phase of the module, for example by setting the air gap between the two module halves. Another possibility is that the module halves partially slide inside one another. Thus, the heart halves may be shaped such that they slide partially overlapping one another to provide an adjustable air gap. The design may also be such that rotation of the rectangular core half 90 degrees to the other half always results in a different air gap. In implementing a large choke family, it may be appropriate to use several different modules. It is essential that the dimensions of the module, the ratios of the winding window and the core cross-section are such that the material cost of the module is minimized and the manufacturing logistics of the entire ballast family are also optimized. The elevation pieces required for air gap insertion can also be integrated directly into the edge pins by means of press-fit plates.

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Figure 15 illustrates the building blocks of the module: coil 55, insulator 56 and core 57. Only half of insulator 56 and core 57 is shown.

Fig. 16 shows an assembled module 58 having a clamping structure 30 59 in the insulating part. Using this bracket, two modules 60 can be joined together to form a conduit 61. Through the conduit 61, the ends of the coils of the modules choke 62 can be conveyed to the connector 63. may be introduced to the switching point via the generated ducting 61.

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Another option for electrically switching the modules is to use separate busbars to which the ends of the coils are connected. The busbar may also pass through the conduit 61. The choke 62 of FIG. 16 further comprises a plurality of capacitors 64.

It may also be expedient to add various end plates and spacers between the modules to provide a mounting structure for further mounting of the finished filter. These can be freely configured for vertical and / or horizontal mounting.

10 The modular core can be implemented in such a way that it meets the so-called barrier insulation requirements, whereby the entire modular component is barrier-free and no external enclosure is required.

15 other electronics, in particular power electronics, can also be integrated into the same mechanical assembly as Fillter, resulting in a compact power-electronics assembly, for example, for powering the grid. Even a generator or motor can be integrated into this same unit. Electronics can also be integrated inside the southern half or part thereof. For example, a cavity can be left in the Sintermetal core where other electro-20 ankles can be mounted.

Figure 17 illustrates how various mounting elements 66 can be integrated into modular structure 65, for example for wall mounting. In the figure the flange 66 is shown to be used for the fastening, but the fastening element 25 could also be another commonly known fastening method, such as a DIN rail fastener. The attachment structures may also be made wholly or partly on the core module.

It may also be appropriate to assemble the Sintermetal core used in the manufacture of modules into several parts. For example, the size of the press may be limited so that the desired heart cannot be produced at one time. Figure 18 shows such a core 67. It is made of parts 68, 69 and 70. Parts 68 and 69 are joined to one another by, for example, gluing, soldering or other commonly known connection method 13. The parts 70 and 69 are connected to each other by further using a fastening element 71 which secures the parts 70 and 69 to each other.

Claims (10)

A method for manufacturing an N-phase modular inductive component comprising at least modules consisting of a core (4, 26, 29, 46, 48, 52, 57, 67), a coil (25, 28, 45, 55) and 5 insulators (47, 56). , characterized in that the modules are mechanically connected by interconnecting the core of the modules and, if necessary, leaving air gaps between the modules. Method according to Claim 1, characterized in that, in the manufacture of the modular inductive component 10, the cores are disposed adjacent to one another and / or superimposed and tightened together by means of fastening means, leaving air gaps between the cores if necessary. Method according to claim 2, characterized in that air gaps are left between the cores 15 by means of the mutual positions of the cores, the elevation blocks, the spacers and / or the like. A modular inductive component made by the method of claim 1, the modules comprising at least a core (4, 26, 29, 46, 48, 52, 57, 67) provided with a center pin (49, 53) and sintered (25). , 28, 45, 55) and insulator (47, 56), characterized in that the core consists of more than one magnetic material. A modular inductive component according to claim 4, characterized in that the core consists of a plurality of separately pressed parts. Modular inductive component according to Claim 4 or 5, characterized in that the material center density (49, 53) has a higher saturation flux than the other core core material. 30 Modular inductive component according to Claim 4, 5 or 6, characterized in that the material of the central core pin (49, 53) is a material of less loss than the material of the other parts of the core. Modular inductive component according to any one of claims 4 to 7, characterized in that the core (48) has at least one or more edge pins (50) and a base 5 connecting the middle pin and the edge pins, all parts being made by sintering. or the like. A modular inductive component according to any one of claims 4 to 8, characterized in that the core (48) preferably has a rectangular base with a circular center pin (49) and with fixing holes (51) in the corners of the base, spaced apart pins (50). Modular inductive component according to one of claims 4 to 9, characterized in that the dielectric is arranged to form a conductor duct (61).