Choke with iron cores and coils

Abstract

Choke (6) comprising a core body (5), wherein the core body (5) comprises: an outer peripheral iron core (20) formed from a plurality of outer peripheral iron core sections (24 to 27), at least three iron cores (41 to 44) arranged inside the outer peripheral iron core (20) and coupled to the plurality of outer peripheral iron core sections (24 to 27), and coils (51 to 54) wound on the at least three iron cores (41 to 44), the radially inner end of each iron core (41 to 44) converging to the center of the outer peripheral iron core (20), wherein gaps (101 to 104) are formed between one of the at least three iron cores (41 to 44) and another iron core adjacent thereto, wherein the iron cores (41 to 44) are magnetically connectable by the gaps (101 to 104), wherein the crossing points of the gaps (101 to 104) are arranged in the center of the core body (5) and the core body (5) is formed with a radial symmetry around this center, and the choke (6) further comprises: a temperature detecting part (S) arranged in the center of an end face of the core body (5), wherein a detector of the temperature detecting part (S) is arranged at the intersection point of the columns (101 to 104), and wherein a circle encompassing the radially outer ends of the gaps (101 to 104) at its circumference represents the largest outer shape of the temperature detecting part (S).

Description

Background of the invention 1. Field of the invention

[0001] The present invention relates to a choke having iron cores and coils. 2. Description of the state of the art

[0002] In the prior art, chokes comprise three coils arranged opposite each other. See, for example, Japanese Unexamined Patent Publication JP H02-203507 A. The iron core of a conventional prior art choke typically has a substantially E-shape, comprising two outer legs and a central leg disposed between them. Coils are wound on each of the two outer legs and the central leg.

[0003] CN 201765902 U discloses a vertical-type triangular iron core reactor, which belongs to the three-phase mini-dry reactor in electrical components. The iron core of the reactor is formed by laminating regularly triangular silicon steel plates. Three iron core windows are distributed sectorally at the apices of the triangle. An air gap groove radiates from the center of the iron core in a Y-shape to the three iron core windows. Each window is embedded with three insulating baffles. A copper-aluminum composite enameled wire winding is formed by piercingly winding it between the insulating baffles. A lead wire is connected to a punch terminal and then installed on a terminal seat.

[0004] US 2017 / 0352476 A1 discloses a reactor capable of measuring the temperature of a magnetic core. The reactor includes an assembly with a magnetic core and a coil having a winding portion, and a temperature sensor that measures the temperature of the reactor. The magnetic core has an inner core portion inserted into the winding portion, and a sensor placement groove is formed in an outer peripheral surface of the inner core portion and disposed within the winding portion. The temperature sensor is located in the sensor placement groove. According to this configuration, it is possible to accurately measure the temperature of the magnetic core during operation of the reactor.

[0005] DE 102016010901 A1 discloses a three-phase reactor comprising: a central iron core, an outer peripheral iron core surrounding the central iron core, and at least three connecting units magnetically connecting the central iron core and the outer peripheral iron core, each of the connecting units comprising at least one connecting iron core, at least one coil wound around the connecting iron core, and at least one gap.

[0006] US 2017 / 0 040 099 A1 discloses an electromagnetic device comprising a static electromagnetic device. The static electromagnetic device comprises a yoke and at least three members comprising windings for forming a magnetic core of the static electromagnetic device, wherein an angle between the at least three members is the same, and at least one of the at least three members or the yoke comprises a lead.

[0007] US 2012 / 0 106 210 A1 discloses power conversion systems and integrated multiphase chokes providing high common-mode to differential-mode choke inductance ratios with circular and triangular shapes for simultaneous differential filtering and common-mode voltage blocking in motor drives and other power conversion applications.

[0008] WO 2010 / 119324 A2 discloses an on-board multi-phase converter with multiple boost coils, comprising: annular self-inductance cores provided for each of the boost coils, each of which has a corresponding boost coil wound thereon; and annular mutual inductance cores provided for each pair of boost coils selected from the plurality of boost coils, each of which has the paired boost coils wound thereon, each of which includes one type of each self-inductance core corresponding to the pair of boost coils. Each of the self-inductance cores and mutual inductance cores has a gap dividing a line in its circumferential direction.

[0009] DE 11 2012 000 976 T5 discloses a small reactor suitable for appropriately measuring the temperature of a coil. The reactor includes a coil with a pair of coil elements and a magnetic core having a pair of inner core portions disposed in the respective coil elements and outer core portions connecting the inner core portions to form a closed magnetic path. Each of the coil elements has an end face shape with a rounded corner portion constituting a corner portion of a rounded rectangle. A temperature sensor is disposed in a trapezoidal space between the rounded corner portions of the coil elements, which face each other. The temperature sensor is pressed to contact the rounded corner portions through the sensor holder portion provided on an insulator, and is configured to appropriately measure the temperature of the coil.When the temperature sensor is arranged in a region where the inner core portions are not arranged in the respective coils of the elements, the coil elements can be positioned close to each other and the size of the reactor can be reduced. Brief description of the invention

[0010] When a reactor is operating, iron cores generate heat. However, the temperature of the iron core depends on load information and fluctuations in heat dissipation, voltage, and current. Furthermore, in the case of a reactor comprising a substantially E-shaped iron core, the temperatures of the two outer legs and the middle leg are different, and generally, the temperature at the proximal end of the middle leg is the highest. Therefore, to accurately understand the heat generation state of a reactor comprising a substantially E-shaped iron core, it is necessary to arrange temperature sensing parts on all of the two outer legs and the middle leg. As a result, the cost increases due to the multiple temperature sensing parts.

[0011] Therefore, a reactor in which the temperature thereof can be easily understood by using a single temperature sensing part is desired.

[0012] The object of the present patent application is solved by the independent patent claims. Advantageous embodiments are described in the dependent patent claims.

[0013] According to a first aspect of the present disclosure, there is provided a reactor comprising, among other things: a core body, the core body comprising an outer peripheral iron core formed of a plurality of outer peripheral iron core portions, at least three iron cores coupled to the outer peripheral iron core portions, and coils wound on the at least three iron cores, wherein gaps capable of being magnetically coupled are formed between one of the at least three iron cores and another iron core adjacent thereto, the reactor further comprising a temperature sensing part disposed at the center of an end surface of the core body.

[0014] In the first aspect, the temperature of each component of the reactor can be detected by a single temperature detection part. Furthermore, since a single temperature detection part is sufficient, it is possible to prevent an increase in costs.

[0015] The object, features and advantages of the present invention as well as other objects, features and advantages will be further explained by the detailed description of the typical embodiments of the present invention shown in the accompanying drawings. Short description of the drawings Fig. 1A is an end view of a throttle according to a first embodiment. Fig. 1B is a partial perspective view of the Fig. 1A shown throttle. Fig. 2A is a first view showing the magnetic flux density of the reactor of the first embodiment. Fig. 2B is a second view showing the magnetic flux density of the reactor of the first embodiment. Fig. 2C is a third view showing the magnetic flux density of the reactor of the first embodiment. Fig. 2D is a fourth view showing the magnetic flux density of the reactor of the first embodiment. Fig. 2E is a fifth view showing the magnetic flux density of the reactor of the first embodiment. Fig. 2F is a sixth view showing the magnetic flux density of the reactor of the first embodiment. Fig. Figure 3 is a diagram showing the relationship between phase and current. Fig. 4 is a cross-sectional view of a throttle according to a second embodiment. Detailed description

[0016] The embodiments of the present invention will be described below with reference to the accompanying drawings. In the following drawings, the same components are designated by the same reference numerals. For ease of understanding, the scales of the drawings have been modified as appropriate.

[0017] In the following description, a three-phase reactor is described primarily as an example. However, the application of the present disclosure is not limited to a three-phase reactor, but can generally be applied to any multi-phase reactor that requires a constant inductance in each phase. Furthermore, the reactor according to the present disclosure is not limited to those provided on the primary side or secondary side of the inverters of industrial robots or machine tools, but can be applied to various machines.

[0018] Fig. 1A is a front view of a throttle based on the first embodiment, and Fig. 1B is a partial perspective view of the Fig. 1A. As shown in Fig. 1A and Fig. As shown in FIG. 1B, a core body 5 of a reactor 6 includes an annular outer peripheral iron core 20 and at least three iron core coils 31 to 33 arranged inside the outer peripheral iron core 20 at equal intervals in the circumferential direction. Furthermore, it is preferable that the number of iron cores be a multiple of three, and the reactor 6 can be used as a three-phase reactor. Note that the outer peripheral iron core 20 may have another shape, such as a circular shape. The iron core coils 31 to 33 include iron cores 41 to 43 and coils 51 to 53 wound on the iron cores 41 to 43, respectively.

[0019] The outer peripheral iron core 20 is formed from a plurality of, for example, three, outer peripheral iron core sections 24 to 26 which are divided in the circumferential direction.

[0020] The outer peripheral iron core sections 24 to 26 are each formed integrally with the iron cores 41 to 43. The outer peripheral iron core sections 24 to 26 and the iron cores 41 to 43 are formed by stacking a plurality of iron plates, carbon steel plates, or electromagnetic steel sheets, or they are formed from a powder core. When the outer peripheral iron core 20 is formed from a plurality of outer peripheral iron core sections 24 to 26, even if the outer peripheral iron core 20 is large, such an outer peripheral iron core 20 can be easily manufactured. Note that the number of iron cores 41 to 43 and the number of iron core sections 24 to 26 are not necessarily the same.

[0021] As from Fig. 1A, the size of the iron cores 41 to 43 is approximately the same and they are arranged at approximately equal intervals in the circumferential direction of the outer peripheral iron core 20. In Fig. 1A, the radially outer ends of the iron cores 41 to 43 are each coupled to the iron core sections 24 to 26.

[0022] Furthermore, the radially inner ends of the iron cores 41 to 43 converge toward the center of the outer peripheral iron core 20, and their apex angles are approximately 120 degrees. The radially inner ends of the iron cores 41 to 43 are separated from each other by gaps 101 to 103, which may be magnetically coupled.

[0023] In other words, in the first embodiment, the radially inner end of the iron core 41 is separated from the radially inner ends of the two adjacent iron cores 42 and 43 by gaps 101 and 103. The same is true for the other iron cores 42 and 43. It is ideal that the sizes of the gaps 101 to 103 are equal to each other, but they do not have to be equal. As can be seen from Fig. As can be seen from Figure 1A, the intersection point of the gaps 101 to 103 is located in the center of the throttle 6. The core body 5 is designed with radial symmetry around this center.

[0024] In the first embodiment, the iron core coils 31 to 33 are arranged inside the outer peripheral iron core 20. In other words, the iron core coils 31 to 33 are surrounded by the outer peripheral iron core 20. Therefore, leakage of the magnetic flux from the coils 51 to 53 to the outside of the outer peripheral iron core 20 can be reduced.

[0025] Fig. 2A to Fig. 2F show the magnetic flux density of the reactor of the first embodiment. Fig. Figure 3 shows the relationship between phase and current. Fig. 3 are the iron cores 41 to 43 of the choke 6 of Fig. 1A is set as the R-phase, S-phase and T-phase respectively. In addition, Fig. 3 The R-phase current is shown by the dotted line, the S-phase current is shown by the solid line, and the T-phase current is shown by the dashed line.

[0026] If in Fig. 3 the electrical angle is π / 6, the Fig. 2A is achieved. Similarly, if the electrical angle is π / 3, the magnetic flux density shown in Fig. 2B is achieved. When the electrical angle is π / 2, the magnetic flux density shown in Fig. 2C is achieved. When the electrical angle is 2π / 3, the magnetic flux density shown in Fig. 2D is achieved. When the electrical angle is 5π / 6, the magnetic flux density shown in Fig. 2E is achieved. When the electrical angle is π, the magnetic flux density shown in Fig. The magnetic flux density shown in Figure 2F is achieved.

[0027] With further reference to Fig. 1A and Fig. 1B, a temperature sensing part S is arranged at the center O of one end of the core body 5. The detector (not shown) of the temperature sensing part S is arranged at the intersection point of the gaps 101 to 103 (coinciding with the center O of the core body 5). In this case, the detector can be arranged at the center O on an end surface of the core body 5, or it can be arranged inside the core body 5, aligned with the center O.

[0028] In one example, the outer shape of the temperature sensing part S has a shape and area large enough to at least partially accommodate the gaps 101 to 103. A circle that encompasses the radially outer ends of the gaps 101 to 103 at its circumference represents the largest outer contour of the temperature sensing part S. In this case, it is possible to make the temperature sensing part S lighter while preventing the temperature sensing part S from interfering with the coils 51 to 53. Furthermore, in another example, the temperature sensing part S may have a size such that it can be arranged only at the intersection point of the gaps 101 to 103 (which coincides with the center O of the core body 5).

[0029] In addition, Fig. 1B outer ends corresponding positions 81 to 83, which correspond to the respective radially outer ends 41a to 43a of the iron cores 41 to 43, are shown in the outer peripheral iron core 20. When the reactor 6 is operated, as shown in Fig. 2A to Fig. 2F, the magnetic flux is not concentrated at the outer ends corresponding to positions 81 to 83.

[0030] The shapes of the outer peripheral iron core portions 24 to 26 and the iron cores 41 to 43 are identical to each other, and they are rotationally symmetrical about the center of the core body 5. Furthermore, the outer peripheral iron core portions 24 to 26 and the iron cores 41 to 43 are formed of the same material. Therefore, the temperature gradients from the center O of one end of the core body 5 to the outer end corresponding to the positions 81 to 83 are identical to each other.

[0031] In other words, the temperatures at the outer end corresponding to positions 81 to 83 depend on the temperature at the center O of one end of the core body 5, the current value and / or voltage value of the coils 51 to 53, and the material and dimensions of the outer peripheral iron core portions 24 to 26 and the iron cores 41 to 43. Therefore, in the first embodiment, by detecting the temperature at the center O of one end of the core body 5 using the temperature detecting part S, the temperature common to the outer ends corresponding to positions 81 to 83 can be estimated.

[0032] For the same reason, the temperatures of other positions of the core body 5, for example, the joint positions where the adjacent peripheral iron core portions are connected to each other, can also be estimated based on the temperature at the center O of one end of the core body 5 detected by the temperature detection part S. In other words, in the first embodiment, by using a single temperature detection part S, it is possible to accurately estimate the temperature of each portion of the reactor 6 based on the temperature at the center O of one end of the core body 5, the current value and / or voltage value of the coils 51 to 53, and the material and dimensions of the outer peripheral iron core portions 24 to 26 and the iron cores 41 to 43. Similarly, it is possible to estimate the temperature or the heat generation state of the coils 51 to 53 of the reactor 6 by using the single temperature detection part S.

[0033] Since only one temperature sensing part S is required, it is possible to prevent an increase in cost compared to the prior art. Note that the temperature sensing part S may be arranged at the center of the other end of the reactor 6, or the temperature sensing part S may be arranged between the centers of both ends of the reactor 6.

[0034] The design of the core body 5 is not limited to the Fig. 1. Another configuration of the core body 5 in which the plurality of iron core coils are surrounded by the outer peripheral iron core 20 is included within the scope of the present disclosure.

[0035] Fig. 4 is a cross-sectional view of the throttle of a second embodiment. Fig. The reactor 6 shown in Fig. 4 includes an outer peripheral iron core 20 formed of outer peripheral iron core portions 24 to 27, and four iron core coils 31 to 34, which are similar to the aforementioned iron core coils and arranged inside the outer peripheral iron core 20. These iron core coils 31 to 34 are arranged at substantially equal intervals in the circumferential direction of the reactor 6. In addition, the number of iron cores is preferably an even number of 4 or more, so that the reactor 6 can be used as a single-phase reactor.

[0036] As can be seen from the drawing, the iron core coils 31 to 34 each comprise iron cores 41 to 44 extending in the radial direction and coils 51 to 54 wound on the respective iron cores. The radially outer ends of the iron cores 41 to 44 are each integrally formed with the adjacent peripheral iron core sections 24 to 27.

[0037] In addition, each of the radially inner ends of the iron cores 41 to 44 is arranged near the center of the outer peripheral iron core 20. In Fig. 4, the radially inner ends of the iron cores 41 to 44 converge toward the center of the outer peripheral iron core 20, and their apex angles are approximately 90 degrees. The radially inner ends of the iron cores 41 to 44 are separated from each other by gaps 101 to 104, which may be magnetically coupled.

[0038] As in Fig.4, a temperature detecting part S is arranged at the center O of one end of the core body 5. As described above, the detector (not shown) of the temperature detecting part S is arranged at the intersection point of the gaps 101 to 104 (coinciding with the center O of the core body 5). The shapes of the outer peripheral iron core portions 24 to 27 and the iron cores 41 to 44 are equal to each other and are formed with rotational symmetry around the center of the core body 5. In addition, the outer peripheral iron core portions 24 to 26 and the iron cores 41 to 43 are formed of the same material as described above. Therefore, the temperature gradients from the center O of one end of the core body 5 to the positions 81 to 84 corresponding to the outer ends are equal to each other.Therefore, for the same reasons as described above, by using a single temperature detecting part S, it is possible to accurately estimate the temperature of each of the positions of the throttle 6. Furthermore, it can be understood that the same effects as described above can be achieved. Aspects of Revelation

[0039] According to the first aspect, a reactor is provided, comprising, among other things: a core body (5), the core body comprising an outer peripheral iron core (20) formed from a plurality of outer peripheral iron core sections (24 to 27), at least three iron cores (41 to 44) coupled to the plurality of outer peripheral iron core sections, and coils (51 to 54) wound on the at least three iron cores, wherein gaps (101 to 104), which can be magnetically coupled, are formed between one of the at least three iron cores and another iron core adjacent thereto, the reactor further comprising a temperature sensing part (S) arranged in the center of an end face of the core body.

[0040] According to the second aspect, the at least three iron cores of the core body in the first aspect are arranged rotationally symmetrically.

[0041] According to the third aspect, the number of at least three iron cores in the first or second aspect is a multiple of three.

[0042] According to the fourth aspect, the number of at least three iron cores in the first or second aspect is an even number not less than four. Effects of the aspects

[0043] In the first and second aspects, the temperature of each component of the reactor can be detected by using a single temperature sensing part. Furthermore, since a single temperature sensing part is sufficient, it is possible to prevent an increase in costs.

[0044] In the third aspect, the reactor can be used as a three-phase reactor.

[0045] In the fourth aspect, the reactor can be used as a single-phase reactor.

Claims

[1] Choke (6) comprising a core body (5), the core body (5) comprising: an outer peripheral iron core (20) formed from a plurality of outer peripheral iron core sections (24 to 27), at least three iron cores (41 to 44) arranged inside the outer peripheral iron core (20) and coupled to the plurality of outer peripheral iron core sections (24 to 27), and coils (51 to 54) wound on the at least three iron cores (41 to 44), the radially inner end of each iron core (41 to 44) converging to the center of the outer peripheral iron core (20), wherein gaps (101 to 104) are formed between one of the at least three iron cores (41 to 44) and another iron core adjacent thereto, wherein the iron cores (41 to 44) are magnetically connectable by the gaps (101 to 104), wherein the crossing points of the gaps (101 to 104) are arranged in the center of the core body (5) and the core body (5) is formed with a radial symmetry around this center, and the choke (6) further comprises: a temperature detecting part (S) arranged in the center of an end face of the core body (5), wherein a detector of the temperature detecting part (S) is arranged at the intersection point of the columns (101 to 104), and wherein a circle encompassing the radially outer ends of the gaps (101 to 104) at its circumference represents the largest outer shape of the temperature detecting part (S). [2] A reactor (6) comprising a core body (5), the core body (5) comprising an outer peripheral iron core (20) formed from a plurality of outer peripheral iron core sections (24 to 27), at least three iron cores (41 to 44) formed inside the outer peripheral iron core (20) and coupled to the plurality of outer peripheral iron core sections (24 to 27), and coils (51 to 54) wound on the at least three iron cores (41 to 44), wherein the radially inner end of each iron core (41 to 44) converges to the center of the outer peripheral iron core (20), wherein gaps (101 to 104) are formed between one of the at least three iron cores (41 to 44) and another iron core adjacent thereto, wherein the iron cores (41 to 44) can be magnetically coupled through the gaps (101 to 104), and the crossing points of the gaps (101 to 104) are arranged in the center of the core body (5) and the core body (5) is formed with a radial symmetry around this center, and the throttle (6) further comprises a temperature sensing part (S) arranged in the core body on a center line of the core body (5), wherein a detector of the temperature detecting part (S) is arranged at the intersection point of the columns (101 to 104), and wherein a circle encompassing the radially outer ends of the gaps (101 to 104) at its circumference represents the largest outer shape of the temperature detecting part (S). [3] Choke (6) according to claim 1 or claim 2, wherein the at least three iron cores (41 to 44) of the core body (5) are arranged rotationally symmetrically. [4] Choke (6) according to one of claims 1 to 3, wherein the number of at least three iron cores (41 to 44) is a multiple of three. [5] Choke (6) according to one of claims 1 to 3, wherein the number of at least three iron cores (41 to 44) is an even number not less than four.

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