Saturable reactor for press fitting with thyristor

Abstract

The invention discloses a saturable reactor for press fitting with a thyristor, and relates to the technical field of direct current power transmission equipment, the saturable reactor comprises a shell, a fixing piece, a plurality of iron cores, a coil, a wiring terminal and a cooling assembly, the shell comprises a left shell and a right shell, the left shell and the right shell are spliced to form an inner cavity, and avoiding openings are formed in the upper end and the lower end of the shell; the wiring terminals are connected with the two ends of the coil, and the cooling assembly is wound around the iron core. The saturable reactor formed by the shell, the fixing piece, the plurality of iron cores, the coil and the wiring terminal can be pressed together with the thyristor to form a compact module, so that the space occupation volume is reduced, the miniaturization of the module is realized, the plurality of saturable reactors can be continuously connected in series, pressed and disassembled through the wiring terminal, and the manufacturing cost is reduced. The required inductance value and the volt-second characteristic are superposed; and through the arranged cooling assembly, heat dissipation is conducted on the interior of the saturable reactor, damage caused by too high temperature in the saturable reactor is avoided, and the service life of the saturable reactor is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of direct current power transmission equipment, and in particular to a saturated reactor for press-fitting with a thyristor. Background Art

[0002] High voltage (HVDC) and ultra-high voltage (VHVDC) direct current transmission systems, including converters, converter transformers, smoothing reactors, AC filters, DC lightning arresters and control and protection equipment. The converter valve is a key equipment in the converter station, and its function is to achieve rectification and inversion. At present, converters mostly use light-controlled or electrically controlled thyristors with high withstand voltage levels. The thyristor is composed of a four-layer PNPN structure and has two states: high resistance and conduction. Its working principle is that under the action of forward voltage, the PNPN junction will be broken down and form a conduction channel. At this time, the thyristor is turned on. Under the action of reverse voltage, the PNPN junction is in a high resistance state. At this time, the thyristor has very little control over the current. Thyristors can pass thousands of amperes of direct current, but due to the limitations of the thyristor PN junction, it takes several microseconds to tens of microseconds from the time the thyristor receives the trigger signal to the time it is fully turned on. If the current change rate di / dt is too large, the PN junction surface has not been fully turned on, and the junction current density near the gate is too large, local overheating will occur and melt, burning through the thyristor. Therefore, it is necessary to add a reactor to the circuit to suppress the slow increase of current during the few microseconds when the thyristor is triggered, so that it does not exceed a certain range, thereby achieving the purpose of protecting the thyristor. After the thyristor is turned on, the reactor should be in a magnetic saturation state during normal operation and will not have a suppressive effect, so a saturated reactor is used.

[0003] Saturated reactor is a kind of reactor with nonlinear saturated core characteristics. Its working principle is based on the on and off state of thyristor elements. When the thyristor element is on, the saturated reactor presents a very low impedance characteristic, which is conducive to reducing the reactance value in the valve and improving the efficiency of the converter valve. On the contrary, when the thyristor element is off, the saturated reactor has a very high impedance to limit the rise of current. This nonlinear impedance characteristic enables saturated reactors to play an important role in power systems.

[0004] The conventional connection method of saturated reactors in DC transmission converter valve systems is to connect the busbar of the reactor to the structural parts of the thyristor through soft connections or the like. The installation method of the connection and the external dimensions of the structural parts occupy a large space. Moreover, if the inductance value range of the reactor is limited after the thyristor parameters are adjusted, it needs to be directly replaced with a more suitable saturated reactor if it is not within the range. In this case, the use requirements of the DC converter valve cannot be met optimally. Moreover, when multiple saturated reactors are press-assembled in series, the temperature inside the saturated reactor is too high, which affects the service life of the saturated reactor.

[0005] In view of this, the present invention is proposed to solve the above technical problems. Summary of the invention

[0006] The present invention aims to provide a saturated reactor for press-fitting with a thyristor, so as to solve the technical problems that the installation method of the existing saturated reactor is not convenient for meeting the use requirements of a DC converter valve and the internal temperature of the existing saturated reactor is too high when in use.

[0007] The technical solution of the present invention is: a saturated reactor for press-fitting with a thyristor, comprising: The outer shell includes a left shell and a right shell, the left shell and the right shell are spliced ​​to form an inner cavity, and avoidance openings are opened at both upper and lower ends of the outer shell; A fixing member, the fixing member is arranged in the inner cavity; A plurality of iron cores, wherein the plurality of iron cores are located inside the fixing member and are spaced apart along the circumference of the housing; Coils, the coils are wound inside multiple iron cores; The wiring terminal is connected to both ends of the coil, and the wiring terminal includes an upper terminal and a lower terminal. The upper terminal and the lower terminal are respectively arranged at the upper and lower ends of the fixing member, and the two ends of the coil are respectively electrically connected to the upper terminal and the lower terminal; The cooling assembly is bent in sequence along the circumferential direction of the coil and attached to the left and right sides of the plurality of iron cores.

[0008] Furthermore, the upper terminal and the lower terminal are respectively located at corresponding avoidance openings.

[0009] Furthermore, the cooling assembly is a cooling pipe, which includes an upper cooling pipe and a lower cooling pipe. The upper cooling pipe and the lower cooling pipe are respectively located on the upper and lower sides of the coil, and the two ends of the upper cooling pipe and the lower cooling pipe are respectively connected to the external circulating water circuit. The upper cooling pipe and the lower cooling pipe are respectively bent and fitted on the left and right sides of multiple iron cores.

[0010] Furthermore, the upper cooling tube and the lower cooling tube are respectively fitted to the upper and lower sides of the coil.

[0011] Furthermore, the iron core includes two C-shaped iron core components, and the two C-shaped iron core components are spliced ​​to form an annular iron core.

[0012] Furthermore, the fixing member includes an upper fixing circular plate and a lower fixing circular plate which are sequentially arranged from top to bottom at intervals; The upper fixed circular plate and the lower fixed circular plate are fixed by a plurality of columns; The upper terminal is arranged on the upper fixed circular plate, and the lower terminal is arranged at the bottom of the lower fixed circular plate; Avoidance holes are provided at the centers of the upper fixed circular plate and the lower fixed circular plate.

[0013] Furthermore, thermally conductive graphite sheets are provided on both upper and lower sides between two adjacent iron cores, the thermally conductive graphite sheets are fitted with the upper cooling tube or the lower cooling tube on the same side, and the two adjacent thermally conductive graphite sheets are connected by silver wires.

[0014] Furthermore, at least one heat dissipation hole is provided on the peripheral wall of the left shell and the right shell; The heat dissipation holes on the left shell and the right shell are symmetrically arranged.

[0015] Furthermore, the upper terminal and the lower terminal are equal in size to the circular pole of the thyristor.

[0016] By adopting the above technical solution, the present invention has the following beneficial effects: The saturated reactor formed by the provided casing, fixings, multiple iron cores, coils and terminals can be pressed together with the thyristor to form a compact module, which reduces the space occupied and realizes the miniaturization of the module. Multiple saturated reactors can be continuously pressed and disassembled in series through the terminals to superimpose the required inductance and volt-second characteristics; and the cooling component is provided to dissipate the heat inside the saturated reactor to avoid damage due to excessive internal temperature of the saturated reactor and increase the service life of the saturated reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are part of this application and are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 A schematic diagram of the structure of a saturated reactor for press-fitting with a thyristor provided in this embodiment of the present application; Figure 2 A transverse cross-sectional view of a saturated reactor for press-fitting with a thyristor provided in this embodiment of the present application; Figure 3 A longitudinal cross-sectional view of a saturated reactor for press-fitting with a thyristor provided in this embodiment of the present application; Figure 4 A schematic diagram of the structure of a saturated reactor for press-fitting with a thyristor provided in this embodiment of the present application with the casing removed; Figure 5 for Figure 4 A schematic diagram of the structure of the saturated reactor provided for press-fitting with the thyristor after removing the upper fixed circular plate; Figure 6 for Figure 4 A schematic diagram of the structure of a saturated reactor provided for press-fitting with a thyristor without the thermally conductive graphite sheet; Figure 7 A schematic structural diagram of a fixing device for a saturated reactor press-fitted with a thyristor provided in this embodiment of the present application.

[0018] Figure numerals: 1. housing; 2. fixing part; 3. coil; 4. iron core; 5. upper terminal; 6. lower terminal; 7. cooling assembly; 8. thermally conductive graphite sheet; 9. heat dissipation hole; 21. upper fixed circular plate; 22. lower fixed circular plate; 23. column.

[0019] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0020] The specific implementation modes of the present invention are further described in detail with reference to the accompanying drawings.

[0021] See also Figures 1 to 7 As shown, an embodiment of the present application provides a saturated inductor for press-fitting with a thyristor, comprising: a shell 1, a fixing member 2, a plurality of iron cores 4, a coil 3, a terminal block and a cooling assembly 7, wherein the shell 1 comprises a left shell and a right shell, the left shell and the right shell are spliced ​​to form an inner cavity, and avoidance openings are provided at both upper and lower ends of the shell 1, the fixing member 2 is arranged in the inner cavity, the plurality of iron cores 4 are located inside the fixing member 2, and the plurality of iron cores 4 are arranged at intervals along the circumference of the shell 1, the coil 3 is wound inside the plurality of iron cores 4, the terminal block is connected to both ends of the coil 3, the terminal block comprises an upper terminal 5 and a lower terminal 6, the upper terminal 5 and the lower terminal 6 are respectively arranged at the upper and lower ends of the fixing member 2, the two ends of the coil 3 are electrically connected to the upper terminal 5 and the lower terminal 6, and the cooling assembly 7 is bent in sequence along the circumferential direction of the coil 3 and attached to the left and right sides of the plurality of iron cores 4.

[0022] It should be noted that the shell 1 is a cylindrical structure, which makes the shell 1 have high mechanical strength, can withstand large structural stress, and the electric field distribution is relatively uniform, which can reduce local discharge; the coil 3 adopts a disc-shaped structure with a single-layer winding, and the coil 3 is wound in a plane, and the coil 3 and the terminal are both made of copper-plated silver material, which can improve the conductivity and corrosion resistance of copper; the fixing part 2 is used to fix multiple iron cores 4, coils 3 and terminal blocks; multiple saturated inductors provided in the embodiments of the present application can be pressed and disassembled in series, and the required inductance and volt-second characteristics can be superimposed.

[0023] In the above scheme, the saturated reactor formed by the provided shell 1, the fixing part 2, the multiple iron cores 4, the coil 3 and the terminal block can be pressed together with the thyristor to form a compact module, which reduces the space occupied and realizes the miniaturization of the module. Multiple saturated reactors can be continuously pressed and disassembled in series through the terminal block to superimpose the required inductance and volt-second characteristics; and the cooling component 7 is provided to dissipate the heat inside the saturated reactor to avoid damage caused by excessive internal temperature of the saturated reactor and improve the service life of the saturated reactor.

[0024] In some possible implementations, see Figure 3 As shown, the upper terminal 5 and the lower terminal 6 are respectively located at corresponding avoidance openings.

[0025] It should be noted that the upper terminal 5 and the lower terminal 6 are equal in size to the circular pole of the thyristor and can be pressed together to form a compact module. Compared with electrical connection or mechanical connection, the connection method between the thyristor and the saturated reactor is simplified, the space occupied volume is reduced, and the miniaturization between the saturated reactor and the thyristor is achieved; the upper terminal 5 and the lower terminal 6 are both in the shape of discs, and the size is consistent with the circular electrode of the thyristor, which can withstand greater external impact and stress.

[0026] In some possible implementations, see Figure 5 and Figure 6 As shown, the cooling assembly 7 is a cooling pipe, which includes an upper cooling pipe and a lower cooling pipe. The upper cooling pipe and the lower cooling pipe are respectively located on the upper and lower sides of the coil, and the two ends of the upper cooling pipe and the lower cooling pipe are respectively connected to the external circulating water circuit, and the upper cooling pipe and the lower cooling pipe are respectively bent and fitted on the left and right sides of multiple iron cores 4.

[0027] In the above scheme, when the current passes through the iron core 4, the end of the iron core 4 close to the upper terminal 5 generates heat, and the heated end of the iron core 4 transfers the heat to the water in the upper cooling tube and the lower cooling tube, thereby absorbing the heat of the heated end of the iron core 4, so that the heat generated by the iron core 4 is continuously absorbed, thereby realizing rapid heat dissipation of the iron core 4, and the two ends of the upper cooling tube and the lower cooling tube are respectively connected to the circulating water circuit of the substation to form an automatic circulation system. When multiple saturated reactors are press-assembled, the upper cold cutting tubes and the lower cooling tubes of the multiple saturated reactors can be respectively connected to the external circulating water circuit.

[0028] In some possible implementations, see Figure 5 and Figure 6 As shown, the upper cooling pipe and the lower cooling pipe are respectively attached to the upper and lower sides of the coil 3. The upper cooling pipe and the lower cooling pipe can also absorb the heat on the coil 3 to prevent the coil 3 from being damaged due to excessive temperature.

[0029] In some possible implementation schemes, the core 4 includes two C-shaped core components, which are spliced ​​together to form a ring-shaped core 4. The two C-shaped core components are spliced ​​and fixed by bolts, which improves the symmetry of the magnetic circuit, is beneficial to the uniform distribution of the magnetic flux, reduces the problem of uneven magnetic saturation caused by the asymmetry of the magnetic circuit, and at the same time reduces the leakage magnetic flux and improves the efficiency of the saturated inductor.

[0030] In some possible implementations, see Figures 4 to 7 As shown, the fixing member 2 includes an upper fixing circular plate 21 and a lower fixing circular plate 22 which are arranged in sequence from top to bottom, and the upper fixing circular plate 21 and the lower fixing circular plate 22 are fixed by a plurality of columns 23, the upper terminal 5 is arranged on the upper fixing circular plate 21, and the lower terminal 6 is arranged at the bottom of the lower fixing circular plate 22, and avoidance holes are opened in the centers of the upper fixing circular plate 21 and the lower fixing circular plate 22.

[0031] In the above solution, the upper terminal 5 and the lower terminal 6 are respectively located in the two avoidance holes, and the avoidance holes facilitate the fixed connection between the two ends of the coil 3 and the upper fixed circular plate 21 and the lower fixed circular plate 22 respectively.

[0032] In some possible implementations, see Figures 2 to 5 As shown, thermally conductive graphite sheets 8 are provided on both upper and lower sides between two adjacent iron cores 4 , and the thermally conductive graphite sheets 8 are fitted with the upper cooling tube or the lower cooling tube on the same side, and the two adjacent thermally conductive graphite sheets 8 are connected by silver wires.

[0033] In the above scheme, the thermally conductive graphite sheet 8 is formed by pressing multiple layers of graphene through a pressing process. The thermally conductive graphite sheet 8 is thin and flexible. Two adjacent thermally conductive graphite sheets 8 are connected by silver wires to reduce resistance and improve the overall thermal conductivity. The thermally conductive graphite sheet 8 has extremely high in-plane thermal conductivity and can quickly absorb the heat generated by the iron core 4 and diffuse it in the plane to avoid heat accumulation inside the saturated reactor. In order to improve the heat dissipation effect, the upper cooling tube or the lower cooling tube and the thermally conductive graphite sheet 8 are fixed by thermally conductive silicone grease to ensure that heat can be smoothly transferred between the upper cooling tube or the lower cooling tube and the thermally conductive graphite sheet 8.

[0034] In some possible implementations, see Figure 1 and Figure 2 As shown, at least one heat dissipation hole 9 is provided on the peripheral wall of the left shell and the right shell, and the heat dissipation holes 9 on the left shell and the right shell are symmetrically arranged.

[0035] In the above scheme, a natural convection air duct is formed by setting the heat dissipation holes 9. When the ambient air temperature is lower than the surface temperature of the thermally conductive graphite sheet 8, the air rises due to the heat, and cold air is replenished from below to form natural convection, which accelerates the air flow and takes away the heat emitted from the surface of the thermally conductive graphite sheet 8, further enhancing the heat dissipation effect and ensuring that the saturated inductor can operate stably and reliably in a high-power and high-temperature environment.

[0036] This specific embodiment is merely an explanation of the invention and is not a limitation of the invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as they are within the scope of protection of the invention, they are protected by patent law.

Claims

1. A saturated reactor for press-fitting with a thyristor, characterized in that: include: A shell (1), the shell (1) comprising a left shell and a right shell, the left shell and the right shell being spliced ​​together to form an inner cavity, and escape openings are provided at both upper and lower ends of the shell (1); A fixing member (2), the fixing member (2) being arranged in the inner cavity; a plurality of iron cores (4), the plurality of iron cores (4) being located inside the fixing member (2), and the plurality of iron cores (4) being arranged at intervals along the circumference of the housing (1); A coil (3), wherein the coil (3) is wound inside the plurality of iron cores (4); A wiring terminal, the wiring terminal being connected to two ends of the coil (3), the wiring terminal comprising an upper terminal (5) and a lower terminal (6), the upper terminal (5) and the lower terminal (6) being respectively arranged at the upper and lower ends of the fixing member (2), and the two ends of the coil (3) being respectively electrically connected to the upper terminal (5) and the lower terminal (6); A cooling component (7), wherein the cooling component (7) is bent in sequence along the circumferential direction of the coil (3) and attached to the left and right sides of the plurality of iron cores (4).

2. The saturated reactor for press-fitting with a thyristor according to claim 1, characterized in that: The upper terminal (5) and the lower terminal (6) are respectively located at corresponding avoidance openings.

3. The saturated reactor for press-fitting with a thyristor according to claim 2, characterized in that: The cooling assembly (7) is a cooling pipe, comprising an upper cooling pipe and a lower cooling pipe, the upper cooling pipe and the lower cooling pipe are respectively located on the upper and lower sides of the coil (3), and both ends of the upper cooling pipe and the lower cooling pipe are respectively connected to an external circulating water circuit, and the upper cooling pipe and the lower cooling pipe are respectively bent in sequence and attached to the left and right sides of the plurality of iron cores (4).

4. The saturated reactor for press-fitting with a thyristor according to claim 3, characterized in that: The upper cooling tube and the lower cooling tube are respectively fitted to the upper and lower sides of the coil (3).

5. The saturated reactor for press-fitting with a thyristor according to claim 4, characterized in that: The iron core (4) comprises two C-shaped iron core components, and the two C-shaped iron core components are spliced ​​to form the annular iron core (4).

6. The saturated reactor for press-fitting with a thyristor according to claim 5, characterized in that: The fixing member (2) comprises an upper fixing circular plate (21) and a lower fixing circular plate (22) which are arranged in sequence from top to bottom at intervals; The upper fixed circular plate (21) and the lower fixed circular plate (22) are fixed via a plurality of columns (23); The upper terminal (5) is arranged on the upper fixed circular plate (21), and the lower terminal (6) is arranged on the bottom of the lower fixed circular plate (22); The upper fixed circular plate (21) and the lower fixed circular plate (22) are both provided with avoidance holes at their centres.

7. The saturated reactor for press-fitting with a thyristor according to claim 6, characterized in that: A heat-conducting graphite sheet (8) is provided on both upper and lower sides between two adjacent iron cores (4); the heat-conducting graphite sheet (8) is fitted to the upper cooling tube or the lower cooling tube on the same side; and the two adjacent heat-conducting graphite sheets (8) are connected by a silver wire.

8. The saturated reactor for press-fitting with a thyristor according to claim 1, characterized in that: At least one heat dissipation hole (9) is provided on the peripheral walls of the left shell and the right shell; The heat dissipation holes (9) on the left shell and the right shell are symmetrically arranged.

9. The saturated reactor for press-fitting with a thyristor according to claim 2, characterized in that: The upper terminal (5) and the lower terminal (6) are equal in size to the circular pole of the thyristor.

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