CN107919657B - A valve tower structure of power electronic branch of ultra-high voltage DC circuit breaker - Google Patents

Abstract

The invention provides a power electronic branch valve tower structure of an ultrahigh voltage direct current breaker, which comprises a plurality of layers of units, a supporting structure for supporting the layers of units and a high-voltage wire slot. Each layer of the valve tower is provided with a maintenance platform, so that when equipment fails, the problem is conveniently checked; the parts related to the valve string are integrated into a whole to form a unit, so that the whole auxiliary unit can be replaced when no time checking problem exists, and meanwhile, after a single independent auxiliary unit is detached, each part is checked one by one, thereby bringing great convenience for maintenance and repair and saving a lot of time.

Description

A valve tower structure of power electronic branch of ultra-high voltage DC circuit breaker

technical field

The invention relates to the technical field of ultra-high voltage direct current transmission, in particular to a valve tower structure for a power electronic branch of an ultra-high voltage direct current circuit breaker.

Background technique

Flexible DC transmission is the most advanced transmission technology today. Since my country's first ±500KV Gezhouba-Shanghai EHVDC transmission line was completed and put into operation in 1989, it has developed rapidly. The commanding heights seized by power companies. At present, there is no DC circuit breaker with large current breaking capacity in the DC system, so the research and development of ultra-high voltage DC circuit breaker is one of the key technologies for the development of DC power grid.

Contents of the invention

In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a compact structure and beautiful appearance. The distribution is reasonable. It adopts a stacked back-to-back structure, and all units and parts can be installed, disassembled and maintained independently, which is a power electronic branch valve tower structure applied to ultra-high voltage DC circuit breakers.

In order to achieve the above purpose, the present invention provides a valve tower structure for a power electronic branch of an ultra-high voltage DC circuit breaker, which includes several layer units, a support structure for supporting the layer units, and a high-voltage wire duct.

The support structure includes a plurality of first support insulators, second support insulators and installation beams arranged between each second support insulators. All the first support insulators enclose a cubic area. The same number of second support insulators are arranged above each first support insulator, and each second support insulator is sequentially connected by a mounting beam. All the second supporting insulators surround a cubic area, and the subunits of each layer are located in the cubic area surrounded by the second supporting insulators, and are arranged in sequence in the vertical direction.

The installation beam includes an upper flange, a lower flange and a beam, the beam is arranged at the bottom of the corresponding layer unit, and the end is fixed between the upper flange and the lower flange; the upper flange and the second supporting insulator above Connection, the lower flange is connected with the second supporting insulator below.

Several power electronic branch units and maintenance platforms are arranged on the layer unit. The structure of the power electronic branch unit is: including a frame assembly and two PP-IGBT modules, two diode modules, 2/N RC snubber circuit modules, a plurality of control board units, a frame, Multiple driver boards and driver power supplies.

The frame assembly includes two side frames and a beam between the two side frames. The side frame is composed of a top frame and a bottom frame under the top frame. Both ends of the cross beam are respectively fixed to a bottom frame. The top frame is located at the top middle of the bottom frame, and the length is shorter than that of the bottom frame. Each module is arranged in the frame.

The PP-IGBT module includes N PP-IGBTs, 2N PP-IGBT radiators, and N+1 insulating pieces, where N is an integer. The PP-IGBT radiators are evenly arranged in a row, and the inside of the PP-IGBT radiators located at both ends are provided with insulators. From one end of the PP-IGBT radiator column to the other end, the PP-IGBT is spaced apart from the insulator. Both ends of the PP-IGBT radiator row are respectively provided with a side pressure plate, and at least one insulating pull rod is arranged between the two side pressure plates, and the insulation pull rod is fixed integrally with the two side pressure plates. A top bolt is provided between one end of the PP-IGBT radiator column and its adjacent side pressure plate, and the PP-IGBTs on both sides of each PP-IGBT radiator are installed in opposite directions.

The diode module includes M diodes and M+1 diode radiators, where M is an integer. The diode radiators are evenly arranged in a row, the diode radiators at both ends are provided with diodes, and each of the other diode radiators is provided with a diode on both sides, and a side pressure plate is provided at each end of the diode radiator row, and the two At least one insulating pull rod is arranged between the two side pressure plates, and the insulation pull rod is fixed as a whole with the two side pressure plates. A top bolt is arranged between one end of the diode radiator row and its adjacent side pressure plate.

The two diode modules are respectively installed on the upper end of the bottom frame along the length direction of the beam, and are respectively located at both ends of the top frame. Two PP-IGBT modules are arranged side by side along the length direction of the beam between the two top frames.

A driving power supply mounting frame and a driving board mounting frame are arranged above the two diode modules respectively for mounting the driving power supply and the sequentially arranged driving boards.

The RC buffer circuit module includes several capacitors and several resistors, the two ends of each capacitor are connected in series through copper bus bars, and the respective capacitors are connected in series through copper bus bars;

There are several high-voltage wire slots, one end of each high-voltage wire slot is grounded, and the other end is connected to the layer unit.

Further, the part of the high voltage wire duct located in the cubic area surrounded by the first supporting insulator is S-shaped.

Further, the support structure also includes cable-stayed insulators. Cable-stayed insulators are arranged between adjacent first support insulators on opposite sides of the cubic area surrounded by the first support insulators. One end of the cable-stayed insulators is connected to a first The top of one supporting insulator is connected to the bottom of the other first supporting insulator at the other end.

Further, each power electronic branch unit is also provided with a first arrester, and the first arrester is connected to the diode radiator through a copper bus bar.

Further, each layer unit is also provided with several second arresters, and each power electronic branch unit is correspondingly provided with a second arrester.

Further, there are four insulating rods of the PP-IGBT module and/or the diode module, which enclose a cubic area, and the PP-IGBT module and/or the diode module are located in the cubic area.

Further, in each power electronic branch unit, each group of pp-IGBTs corresponds to four diodes in the diode module to form a diode bridge structure circuit; in the diode bridge structure circuit, the source and drain of each pp-IGBT are There is a diode connected, and the source is connected to the anode of the diode, and the drain is connected to the cathode of the diode; in the whole diode bridge structure circuit, the two diodes connected to the source are connected together, and the two connected to the drain The anodes of the two diodes are connected together; each diode bridge structure circuit is connected in series.

Further, each diode bridge structure circuit is connected in parallel with an RC snubber circuit.

Further, each layer unit is provided with six power electronic branch units.

Compared with prior art, the beneficial effect of the present invention is:

1. Structural design integration, all modules, units, and devices are integrated, stacked and arranged back to back. The structure is more compact, reasonable and beautiful.

2. The division by function is more clear, and all auxiliary modules and units can be installed, disassembled and maintained independently. Effectively save the time of installation and wiring.

3. A maintenance platform is installed on each floor of the valve tower, which is convenient for troubleshooting when the equipment fails; the parts related to the valve string are integrated to form a unit, so that not only can the entire subsidiary Units can be replaced, and a single independent subsidiary unit can also be removed, and each part can be checked one by one, which brings great convenience to maintenance and repair, and saves a lot of time.

Description of drawings

Figure 1 is a three-dimensional front view of the power electronics branch unit.

Figure 2 is a three-dimensional view of the back of the power electronics branch unit.

Figure 3 is a three-dimensional view of the frame assembly.

Fig. 4 is a three-dimensional diagram of a PP-IGBT module.

Fig. 5 is a three-dimensional diagram of a diode module.

Fig. 6 is a three-dimensional diagram of the RC snubber circuit module.

Fig. 7 is a three-dimensional view of the left lightning arrester unit.

Fig. 8 is a topology circuit diagram of a diode bridge structure buffer branch.

Fig. 9 is an overall schematic diagram of the present invention.

Fig. 10 is a schematic diagram of a high-voltage trunking.

In the figure: 1. Left arrester unit, 2. Left diode module, 3. PP-IGBT module, 4. Right diode module, 5. Right arrester module, 6. RC buffer circuit module, 7. Control board unit, 8. Drive Board, 9. Drive power supply, 10. PP-IGBT, 11. PP-IGBT radiator, 12. Insulator, 13. Diode, 14. Diode radiator, 15. Capacitor, 16. Resistor, 17. Copper busbar, 18. Lightning arrester module, 19. Diode bridge structure circuit, 20. Buffer absorption circuit, 21. Diode bridge structure buffer branch, 22. Electronic branch unit, 23. Second lightning arrester, 24. Installation beam, 25. The first Two supporting insulators, 26. the first supporting insulator, 27. cable-stayed supporting insulators, 28. high voltage trunking, 29. maintenance platform.

Detailed ways

As shown in FIG. 9 , the valve tower structure of the power electronic branch of the ultra-high voltage DC circuit breaker of the present invention includes several layer units, a support structure for supporting the layer units, and a high-voltage wire groove 28 .

Introduce them separately below.

1. Support structure

The support structure includes a plurality of first support insulators 26, second support insulators 25 and installation beams 24 arranged between each second support insulators 25; all first support insulators 26 enclose a cubic area; each first support The same number of second support insulators 25 are arranged above the insulator 26, and each second support insulator 25 is sequentially connected by a mounting beam 24; all second support insulators 25 form a cubic area, and each layer of subunits is located on the second support insulator 25 In the enclosed cubic area, and set in sequence in the vertical direction;

The installation crossbeam 24 includes an upper flange, a lower flange and a crossbeam, the crossbeam is arranged at the bottom of the corresponding layer unit, and the end is fixed between the upper flange and the lower flange at the corresponding position. Each upper flange is connected with the upper second supporting insulator, and the lower flange is connected with the lower second supporting insulator 25 . The beam can be made of aluminum material.

Preferably, the support structure further includes a cable-stayed support insulator 27, and a cable-stayed support insulator 27 is arranged between adjacent first support insulators 26 on opposite sides of the cubic area surrounded by the first support insulator 26. One end of the supporting insulator 27 is connected to the top of one first supporting insulator 26 , and the other end is connected to the bottom of the other first supporting insulator 26 . There are two diagonally-stayed support insulators 27 arranged crosswise between two adjacent second support insulators 25 . The effect of the cable-stayed support insulator 27 is to ensure the transverse shearing force and make the valve tower more firm. Prevent the vibration from causing the valve tower to roll over.

2. Layer unit

Several power electronic branch units and a maintenance platform 29 are arranged on the layer unit. Introduce respectively below.

a. Power electronics branch unit

As shown in Figure 1 and Figure 2, the power electronic branch unit of the ultra-high voltage DC circuit breaker of the present invention includes a frame assembly and two PP-IGBT modules 3, two diode modules, and multiple RC buffers arranged in the frame assembly A loop module 6, a plurality of control board units 7, a frame assembly, a plurality of driving boards 8, and a driving power supply 9.

Each part is described below.

a.1. Frame components

As shown in Figure 3, the frame assembly includes two side frames and a beam between the two side frames, the side frame is composed of a top frame and a bottom frame under the top frame, and the two ends of the beam are respectively fixed to a on the bottom frame; the top frame is located at the top middle of the bottom frame, and the length is shorter than the bottom frame. The function of the frame is to install each module. It can be seen from the figure that each module is set in the space surrounded by the side frame and the beam.

a.2. PP-IGBT module 3

As shown in FIG. 4 , the PP-IGBT module 3 includes N PP-IGBTs 10 , 2N PP-IGBT radiators 11 , and N+1 insulating pieces 12 , where N is an integer. N is 22 in this embodiment.

Each PP-IGBT radiator 11 is evenly arranged in a row, and the inner side of the PP-IGBT radiator 11 located at both ends is provided with an insulator 12. From one end of the PP-IGBT radiator 11 to the other end, the PP-IGBT 10 and the insulator 12 interval setting. The PP-IGBT radiator 11 not only dissipates heat from the PP-IGBT 10 device, but also conducts current. The PP-IGBTs 10 on both sides of each PP-IGBT radiator 11 are installed in opposite directions, forming a group of PP-IGBTs 10 .

The two ends of the column where the PP-IGBT radiator 11 is located are respectively provided with a side pressure plate, and at least one insulating pull rod is arranged between the two side pressure plates, and the insulation pull rod is used to be fixed with the two side pressure plates as a whole, so as to 11 rows of PP-IGBT radiators are fixed between two side pressure plates. A top bolt is provided between one end of the PP-IGBT radiator 11 row and its adjacent side pressure plate, and at least one belleville spring is provided outside the top bolt (as shown in FIG. 4 ). The top bolt is connected to the PP-IGBT module 3 by threads. When the components of the valve string module need to be replaced, the pressure on the whole module can be removed by adjusting the position of the top bolt for replacement and maintenance. When installing again, the module can be press-fitted as long as the thread is tightened.

In this embodiment, there are three Belleville springs. The belleville spring plays the role of ensuring the pressure after compression, ensuring the conduction requirement of PP-IGBT 10 .

Further, it is preferable to set four insulating tie rods to enclose a cubic area, and the column where the PP-IGBT radiator 11 is located is located in the cubic area. The insulating pull rod is fixed together with the side pressure plate adjacent to the belleville spring through nuts and bolts.

a.3. Diode module

As shown in FIG. 5 , the diode 1 press-fit valve string module structure of the ultra-high voltage DC circuit breaker of the present invention includes N diodes 13 and N+1 diode radiators 14 , where N is an integer. There are 22 diodes in this embodiment.

Each diode radiator 14 is evenly arranged in a row, and a diode 13 is arranged on the inner side of the diode radiator 14 at both ends, and a diode 13 is arranged on both sides of each other diode radiator 14 . The diode radiator 14 not only plays the role of cooling the diode 13, but also plays the role of conducting current.

Two ends of the 14 rows of diode radiators are respectively provided with a side pressure plate, and at least one insulating pull rod is arranged between the two side pressure plates, and the insulation pull rod is used to be fixed together with the two side pressure plates to secure the diode radiator 14 columns are fixed between two side pressure plates. A top bolt is arranged between one end of the row of diode radiators 14 and the adjacent side pressure plate 3 , and a butterfly spring is set over the top bolt. The top bolt is connected to the PP-IGBT module by thread. When the components of the valve string module need to be replaced, the pressure on the whole module can be removed by adjusting the position of the top bolt for replacement and maintenance. When installing again, the module can be press-fitted as long as the thread is tightened.

In this embodiment, there are three Belleville springs. The belleville spring plays the role of ensuring the pressure after compression to ensure the conduction requirements of the diode.

In the direction of the 14 rows of diode radiators, the diodes are in groups of two, and the installation direction of each group of diodes is opposite. Of course, the mounting direction of the diodes can be changed according to the circuit of the EHVDC circuit breaker, and the mounting direction of each group of diodes can be the same.

Further, it is preferable to set four insulating tie rods to enclose a cubic area, and 14 rows of diode radiators are located in the cubic area. The insulating pull rod is fixed together with the side pressure plate adjacent to the belleville spring through nuts and bolts.

Two diode modules are respectively installed on the upper end of the bottom frame along the length direction of the beam, and are respectively located at both ends of the top frame, as shown in Figure 1, the left diode module 2 and the right diode module 4; two PP-IGBT modules 3 The length direction is arranged side by side between two top frames.

The two diode modules are respectively provided with a driving power supply 9 mounting frame and a driving board 8 mounting frame, which are respectively used for mounting the driving power 9 and the sequentially arranged driving boards 8 .

a.4. Drive power supply 9, drive board 8, control board unit 7

The two diode modules are respectively provided with a driving power supply 9 mounting frame and a control board unit 7 mounting frame, which are respectively used for mounting the driving power 9 and the control board units 7 arranged in sequence. A driver board 8 installation frame is arranged above the two diode modules for installing the driver boards 8 arranged in sequence. It can be seen from Figure 1 that the two ends of each mounting frame are installed on the two side pressure plates of the module below it, and several horizontal bars are arranged in sequence on the mounting frame, and the horizontal bars are used to install the driving power supply 9, the driving board 8. Control panel unit 7.

Every two PP-IGBTs 10 of the PP-IGBT module 3 and 4 diodes of the adjacent diode module form a diode bridge structure circuit 19, and all the diode bridge structure circuits 19 are connected in series. The PP-IGBT module 3 and the diode module are connected through copper bus bars 17 .

a.5. RC snubber circuit module 6

Each RC buffer circuit module 6 is arranged at the lower end of the PP-IGBT module 3 and fixed on the beam. Structurally, the space is effectively utilized, and the structure is more compact. The diode module and the RC snubber circuit module 6 are placed in parallel. This structure not only facilitates installation and disassembly, but also reduces the connection distance of copper busbars and reduces material costs. The three-dimensional diagram of the RC buffer circuit module 6 shown in FIG. 6 , the RC buffer circuit is composed of a capacitor 15 , a resistor 16 and a copper busbar 17 . Wherein the capacitor 15 and the resistor 16 are connected in series to form a buffer absorption circuit 20 . The capacitor 15 and the resistor 16 are fixed on the upper copper busbar 17, and this connection method can reduce stray inductance.

Further, it also includes a first lightning arrester 18, the first lightning arrester 18 is connected to the diode radiator 14 through the copper busbar 17, the number of lightning arresters in the first lightning arrester 18 is N/2, and each lightning arrester is connected in parallel with an RC buffer circuit. As shown in FIG. 1 , in this embodiment, the arresters are divided into two groups, which are respectively arranged on the left and right sides of the units, called left arrester unit 1 and right arrester unit 5 . In each group, individual lightning arresters are fixed by insulating beams (as shown in Figure 6). For example, the left lightning arrester unit 1 is provided with 6 lightning arrester units, which are formed by fixing 6 lightning arresters through insulating beams. The right arrester unit 5 is formed by fixing five arresters through insulating beams. The first lightning arrester 18 is arranged beside the bottom frame along the length direction of the beam.

Further, each group of pp-IGBTs corresponds to four diodes 13 in the diode module to form a diode bridge structure circuit 19; in the diode bridge structure circuit 19, the source and drain of each pp-IGBT10 are connected to a diode 13, and the source is connected to the anode of the diode 13, and the drain is connected to the cathode of the diode 13; in the whole diode bridge structure circuit 19, the two diodes connected to the source are connected together, and the two diodes connected to the drain are connected together. The anodes of the two diodes are connected together; each diode bridge structure circuit 19 is connected in series to form a diode bridge structure buffer branch 21.

In the present invention, each layer unit is provided with six power electronic units. The maintenance platform 29 is set in the middle of the layer unit, and there are three power electronic units on each side.

Each layer unit is also provided with a number of second arresters 23, and each power electronic branch unit is correspondingly provided with a second arrester 23.

Each module of the power electronic branch unit can be disassembled and maintained separately.

b. Maintenance platform 29

The maintenance platform 29 can bear a weight of 400kg, which is convenient for maintenance personnel to overhaul and maintain.

3. High voltage trunking 28

As shown in FIG. 10 , there are several high-voltage wire slots 28 , one end of each high-voltage wire slot 28 is grounded, and the other end is connected to the layer unit.

Cables and optical fibers climb through the high voltage wireway 28 to the floor unit from below. The part of the high-voltage trunking 28 located in the cubic area surrounded by the first support insulator 26 is S-shaped, which can effectively increase the creepage distance and ensure the use under ultra-high voltage.

Claims (8)

1. A valve tower structure for an ultra-high voltage DC circuit breaker power electronics branch, characterized in that it includes several layer units, a support structure for supporting the layer units, and a high-voltage wire slot; The support structure includes several first support insulators, second support insulators and installation beams arranged between each second support insulator; all the first support insulators enclose a cubic area; each first support insulator is provided with the same The number of second support insulators, each second support insulators are connected in sequence with installation beams; all the second support insulators enclose a cubic area, and each layer of subunits is located in the cubic area surrounded by the second support insulators, and in the vertical Set sequentially in the direction; The support structure also includes cable-stayed support insulators. Cable-stayed support insulators are arranged between adjacent first support insulators on opposite sides of the cube area surrounded by the first support insulators. One end of the cable-stayed support insulators is connected to a The top of the first supporting insulator, the other end is connected to the bottom of another first supporting insulator; there are two diagonally-stayed supporting insulators arranged crosswise between two adjacent second supporting insulators, and the diagonally-stayed supporting insulators are used to ensure transverse shearing force; The installation beam includes an upper flange, a lower flange and a beam, the beam is arranged at the bottom of the corresponding layer unit, and the end is fixed between the upper flange and the lower flange; the upper flange and the second supporting insulator above connection, the lower flange is connected with the second supporting insulator below; A number of power electronic branch units and maintenance platforms are arranged on the layer unit; the structure of the power electronic branch unit is: including a frame component and two PP-IGBT modules and two diode modules arranged in the frame component, Multiple RC buffer circuit modules, multiple control board units, frame, multiple drive boards, drive power supply; The frame assembly includes two side frames and a beam between the two side frames, the side frame is composed of a top frame and a bottom frame under the top frame, and the two ends of the cross beam are respectively fixed to a bottom frame; The top frame is located in the upper middle of the bottom frame, and the length is shorter than the bottom frame; each module is set in the frame; The PP-IGBT module includes N PP-IGBTs, 2N PP-IGBT radiators, and N+1 insulators, where N is an integer; each PP-IGBT radiator is evenly arranged in a row, and the PP-IGBTs at both ends Insulators are provided on the inner side of the radiator; from one end of the PP-IGBT radiator row to the other end, PP-IGBT and the insulator are arranged at intervals; two ends of the PP-IGBT radiator row are provided with a side pressure plate, and the two sides At least one insulating tie rod is arranged between the pressing plates, and the insulating drawing rod is fixed together with the two side pressing plates; a top bolt is arranged between one end of the PP-IGBT radiator row and the adjacent side pressing plates, and each PP-IGBT The installation direction of PP-IGBT on both sides of the radiator is opposite; The diode module includes M diodes and M+1 diode radiators, wherein M is an integer; each diode radiator is evenly arranged in a row, and diodes are arranged on the inside of the diode radiators at both ends, and each of the other diode radiators is arranged on both sides. Each is provided with a diode, and two ends of the diode radiator row are respectively provided with a side pressure plate, and at least one insulating pull rod is arranged between the two side pressure plates, and the insulation pull rod is fixed with the two side pressure plates as a whole; A top bolt is arranged between one end of the diode radiator row and its adjacent side pressure plate; Two diode modules are respectively installed on the upper end of the bottom frame along the length direction of the beam, and are respectively located at both ends of the top frame; two PP-IGBT modules are arranged side by side along the length direction of the beam between the two top frames; The two diode modules are respectively provided with a driving power supply mounting frame and a driving board mounting frame, which are respectively used to install the driving power supply and the sequentially arranged driving boards; The RC buffer circuit module includes several capacitors and several resistors, the two ends of each capacitor are connected in series through copper bus bars, and each capacitor is connected in series through copper bus bars; There are several high-voltage wire slots, one end of each high-voltage wire slot is grounded, and the other end is connected to the layer unit. 2. The valve tower structure of the power electronic branch of the ultra-high voltage DC circuit breaker according to claim 1, wherein the part of the high-voltage wire duct located in the cubic area surrounded by the first support insulator is S-shaped. 3. The valve tower structure of the power electronic branch circuit of the ultra-high voltage direct current circuit breaker as claimed in claim 1, wherein each power electronic branch circuit unit is also provided with a first arrester, and the first arrester and the diode radiator are connected through copper Bus connection. 4. The valve tower structure of the power electronic branch circuit of the ultra-high voltage DC circuit breaker as claimed in claim 1, wherein each layer unit is also provided with a plurality of second arresters, and each power electronic branch circuit unit is correspondingly provided with a second arrester . 5. The EHVDC circuit breaker power electronic branch valve tower structure according to claim 1, characterized in that there are four insulating pull rods of PP-IGBT modules and/or diode modules, which form a cubic area, PP- IGBT modules and/or diode modules are located within this cuboid area. 6. The ultra-high voltage direct current circuit breaker power electronic branch valve tower structure as claimed in claim 1, characterized in that, in each power electronic branch unit, each group of PP-IGBT corresponds to four diodes in the diode module to form a diode Bridge structure circuit; in the diode bridge structure circuit, each PP-IGBT source and drain are connected to a diode, and the source is connected to the anode of the diode, and the drain is connected to the cathode of the diode; the whole diode bridge In the structural circuit, the cathodes of the two diodes connected to the source are connected together, and the anodes of the two diodes connected to the drain are connected together; each diode bridge structure circuit is connected in series. 7. The valve tower structure of the power electronic branch of the ultra-high voltage DC circuit breaker according to claim 6, wherein each diode bridge circuit is connected in parallel with an RC snubber circuit. 8. The valve tower structure of the power electronic branch circuit of the ultra-high voltage DC circuit breaker according to claim 1, wherein each layer unit is provided with six power electronic branch circuit units.