A DC circuit breaker equivalent valve group

Abstract

The present invention relates to a DC circuit breaker equivalent valve group, comprising a bracket and a valve string, an RCD component and a bypass switch component installed on the bracket, wherein the valve string comprises two, and each valve string comprises a forward IGBT and a reverse IGBT connected in series, and two IGBTs arranged in the same direction in the two valve strings are connected in parallel, the RCD component comprises two groups, respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of RCD components comprises a capacitor, a resistor and a diode, and the capacitor and the resistor are connected in series and then connected in parallel with the diode, and the bypass switch component comprises two groups, respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of bypass switch components comprises a bypass switch. The present invention can reduce the overall volume on the basis of ensuring the consistency of the function with the main branch of the DC circuit breaker, so as to meet the size requirements of test equipment such as a test platform or a temperature box, thereby facilitating the operation of the test.

Description

Technical Field

[0001] The invention belongs to the technical field of direct current circuit breakers, and in particular relates to an equivalent valve group for a direct current circuit breaker. Background Art

[0002] High-voltage DC circuit breakers are the core equipment for building multi-terminal flexible DC systems, which can improve the economy and reliability of system operation. DC circuit breakers can quickly disconnect short-circuit fault currents in DC systems, cut off fault lines, and isolate converter stations from fault points within milliseconds. The main branch is an important part of the DC circuit breaker, which can withstand the system rated current for a long time and the system fault current for a short time, and the fault is instantly locked to achieve forced commutation.

[0003] With the development of high-voltage DC circuit breaker technology, the demand for DC circuit breaker testing has emerged. Due to the complex structure and large size of the current DC circuit breaker, it is unable to enter the test platform during high and low temperature environment tests, extreme high temperature environment tests, aging tests, etc. due to size limitations. Summary of the invention

[0004] The object of the present invention is to provide a DC circuit breaker equivalent valve group to solve the problem that the DC circuit breaker cannot meet the test requirements.

[0005] A DC circuit breaker equivalent valve group of the present invention is implemented as follows:

[0006] A DC circuit breaker equivalent valve group comprises a bracket and a valve string, an RCD component and a bypass switch component mounted on the bracket, wherein the valve string comprises two, and each valve string comprises a forward IGBT and a reverse IGBT connected in series, and two IGBTs arranged in the same direction in the two valve strings are connected in parallel, the RCD component comprises two groups, which are respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of RCD components comprises a capacitor, a resistor and a diode, and the capacitor is connected in series with the resistor and then connected in parallel with the diode, the bypass switch component comprises two groups, which are respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of bypass switch components comprises a bypass switch.

[0007] Furthermore, the bracket includes two C-shaped insulating beams with upper and lower openings facing each other and arranged in pairs, two valve strings are installed in parallel between the two pairs of C-shaped insulating beams, the RCD component is arranged on the outside of one of the valve strings, and the bypass switch component is arranged in a sunken manner below the valve string.

[0008] Furthermore, universal wheels are installed at both ends of the two C-shaped insulating beams located below.

[0009] Furthermore, two IGBTs of the same direction are connected in parallel via copper busbar I.

[0010] Furthermore, a pair of driving modules are arranged above the valve string, and each driving module is respectively connected to two adapters, and the adapter connected to the same driving module is connected to two IGBTs in the same direction.

[0011] Furthermore, one end of the two driving modules is mounted on the radiator of the two IGBTs of the same valve group through a metal bracket, and the other end is mounted on the radiator of the two IGBTs of another valve group through a metal bracket and an insulating pad.

[0012] Furthermore, a pair of power supply coils are provided on the valve string at the end, and the power supply coils are respectively connected to the two driving modules.

[0013] Furthermore, each bypass switch assembly also includes a bypass switch power supply coil arranged on one side of the bypass switch, and a control module arranged on the other side of the bypass switch, the bypass switch is connected to the control module, and the control module is connected to the bypass switch power supply coil.

[0014] Furthermore, the bypass switches are connected to the copper busbars I connected in parallel with the IGBTs in the same direction through the copper busbars II.

[0015] Furthermore, an external power supply connection copper bus is provided between two IGBTs of the same direction.

[0016] After adopting the above technical solution, the present invention has the following beneficial effects:

[0017] (1) The present invention concentrates the valve string, RCD assembly and bypass switch assembly on the bracket, thereby reducing the overall volume while ensuring the consistency of the function of the main branch of the DC circuit breaker, so as to meet the size requirements of test equipment such as a test platform or a temperature chamber, thereby facilitating the test operation;

[0018] (2) The RCD component in the present invention forms an RCD loop and is connected in parallel with the IGBT in two directions, which can buffer and protect the IGBT;

[0019] (3) In the present invention, the bypass switch is connected in parallel with the IGBTs in two directions respectively. When the current in a certain IGBT circuit exceeds the tolerance current, the IGBT can be protected by closing the bypass switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 It is a structural diagram of an equivalent valve group of a DC circuit breaker in a preferred embodiment of the present invention;

[0022] Figure 2 It is a structural diagram of an equivalent valve group of a DC circuit breaker in a preferred embodiment of the present invention;

[0023] Figure 3 is a front view of an equivalent valve group of a DC circuit breaker according to a preferred embodiment of the present invention;

[0024] Figure 4 yes Figure 3 Cross-section view in the AA direction;

[0025] Figure 5 is a top view of an equivalent valve group of a DC circuit breaker according to a preferred embodiment of the present invention;

[0026] Figure 6 yes Figure 5 A magnified view of part B;

[0027] Figure 7 It is a left view of an equivalent valve group of a DC circuit breaker according to a preferred embodiment of the present invention;

[0028] Figure 8 yes Figure 7 Cross-sectional view in the mid-CC direction;

[0029] Fig. 9 is a structural diagram of two valve strings of a DC circuit breaker equivalent valve group according to a preferred embodiment of the present invention;

[0030] Fig.10 is a structural diagram of two valve strings of a DC circuit breaker equivalent valve group according to a preferred embodiment of the present invention;

[0031] In the figure: bracket 1, C-shaped insulating beam 101, universal wheel 102, U-shaped frame 103, valve string 2, IGBT201, clamping end plate 202, pull rod 203, radiator 204, disc spring 205, cushion block 206, weight reduction hole 207, radiator fin 208, copper busbar I 209, drive module 210, adapter 211, metal bracket 212, insulating cushion block 213, power supply coil 214, external power supply connecting copper busbar 215, RCD component 3, capacitor 301, resistor 302, diode 303, U-shaped seat 304, copper busbar III 305, copper busbar IV 306, metal frame 307, bypass switch component 4, bypass switch 401, bypass switch power supply coil 402, control module 403, copper busbar II 404. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 1-10 As shown, a DC circuit breaker equivalent valve group includes a bracket 1 and a valve string 2, an RCD component 3 and a bypass switch component 4 installed on the bracket 1, the valve string 2 includes two, and each valve string 2 includes a forward IGBT and a reverse IGBT connected in series, and the two IGBTs 201 arranged in the same direction in the two valve strings 2 are connected in parallel, the RCD component 3 includes two groups, which are respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of RCD components 3 includes a capacitor 301, a resistor 302 and a diode 303, the capacitor 301 is connected in series with the resistor 302 and then connected in parallel with the diode 303, the bypass switch component 4 includes two groups, which are respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of bypass switch components 4 includes a bypass switch 401.

[0035] See also Figure 9-10 Specifically, each valve string 2 includes two clamping end plates 202 and a pull rod 203 connected between the clamping end plates 202, two IGBTs 201 connected in reverse series and a heat sink 204 installed on both sides of each IGBT 201 are arranged between the two clamping end plates 202, and a disc spring 205 is arranged between one of the clamping end plates 202 and the heat sink 204 adjacent thereto. The arrangement of the disc spring 205 facilitates pressurization and pressure relief of the valve string 2.

[0036] The use of two valve strings 2 can play a role in current diversion, thereby achieving a protective effect on the valve string 2 and the entire DC circuit breaker equivalent valve group.

[0037] The present invention integrates a valve string 2, an RCD assembly 3 and a bypass switch assembly 4 on a bracket 1, wherein the bracket 1 includes two C-shaped insulating beams 101 with upper and lower openings facing each other and arranged in pairs, two valve strings 2 are installed in parallel between the two pairs of C-shaped insulating beams 101, the RCD assembly 3 is arranged on the outside of one of the valve strings 2, and the bypass switch assembly 4 is arranged in a sunken manner below the valve string 2.

[0038] Specifically, the clamping end plate 202 of the valve string 2 is arranged between the upper and lower opposite C-shaped insulating beams 101 and fixed by bolts. In order to facilitate the parallel connection of the same-direction IGBT201 and the connection with the bypass switch assembly 4, a cushion block 206 is arranged at the bottom of the clamping end plate 202.

[0039] Preferably, the clamping end plate 202, the disc spring 205, and the cushion block 206 are all made of aluminum, which can appropriately reduce the weight of the entire equivalent valve group. In addition, a weight-reducing hole 207 is provided on the clamping end plate 202, which can not only further reduce the mass of the equivalent valve group, but also facilitate hand-held force application through the weight-reducing hole, thereby increasing the convenience of moving the valve string 2.

[0040] Preferably, the C-shaped insulating beam 101 is made of epoxy insulating material.

[0041] The resistor 302 and the capacitor 301 in the RCD component 3 are connected in series and then in parallel with the diode 303 to form an RCD loop, which is a buffer circuit, and can play a buffering role, thereby protecting the IGBT201. In the present invention, two groups of RCD components 3 are symmetrically arranged at one end of the bracket 1, wherein the two capacitors 301 are installed on the C-shaped insulating beam 101 located below through the U-shaped seat 304, and the opposite side of the capacitor 301 is connected in parallel with the resistor 302 through a soft connection, and one end of the parallel line is directly connected in series with one end of the diode 303, and the other end is connected to the heat sink fin 208 of one of the heat sinks 204 of the adjacent IGBT201, and the other end of the diode 303 is connected to the heat sink fin 208 of another heat sink 204 of the adjacent IGBT201.

[0042] Preferably, in order to increase the neatness and simplicity of the position distribution of the diode 303, the resistor 302 and the capacitor 301, the diode 303 is connected to the heat sink fin 208 of the heat sink 204 of the IGBT201 close to the clamping end plate 202, and the parallel end of the resistor 302 and the capacitor 301 is connected to the heat sink fin 208 of another heat sink 204 of the IGBT201.

[0043] Specifically, the diode 303 is connected in series with the capacitor 301 through the copper bar III 305 , and the capacitor 301 is connected in series with the radiator fin 208 through the copper bar IV 306 , and both ends of the resistor 302 are connected in parallel to the copper bar III 305 and the copper bar IV 306 through the metal frame 307 .

[0044] The bracket 1 uses four C-shaped insulating beams 101 arranged in pairs, and the valve string 2 and the RCD component 3 do not exceed the ends of the C-shaped insulating beam 101 during installation, and the position of at least one capacitor 301 does not exceed the side of the C-shaped insulating beam 101. In this way, the equivalent valve group can be placed upright in three directions of height, length and width to meet EMC and other test requirements.

[0045] In order to facilitate the operation of the equivalent valve group, universal wheels 102 are respectively installed at both ends of the two C-shaped insulating beams 101 located at the bottom.

[0046] In the process of moving the equivalent valve group, it can be operated by the universal wheel 102, thereby improving the convenience of its movement.

[0047] When the IGBTs 201 arranged in the same direction are connected in parallel, in order to simplify the parallel circuit, the two IGBTs 201 arranged in the same direction are connected in parallel via a copper busbar I 209 .

[0048] Specifically, radiator fins 208 are provided under the radiators 204 on both sides of the IGBT 201 , and the copper busbars I 209 respectively connect the radiator fins 208 of the two IGBTs 201 in the same direction in pairs, thereby realizing the parallel connection of the IGBTs in the same direction in the two valve strings.

[0049] In order to ensure the normal operation of the IGBT 201 , a pair of driving modules 210 are arranged above the valve string 2 , and each driving module 210 is respectively connected to two adapters 211 , and the adapter 211 connected to the same driving module 210 is connected to two IGBTs 201 in the same direction.

[0050] Specifically, two driving modules 210 are installed in parallel in the direction of the series connection of IGBT201, and the adapters 211 connected thereto are arranged on both sides thereof. The adapters 211 are installed on the radiator 204 adjacent to the two IGBT201 on the valve string 2, and are connected to the IGBT201 opposite thereto through connecting wires, and the driving module 210 is connected to the adapters 211 on both sides thereof through connecting wires, that is, connected to the adapters 211 connected to the IGBT201 in the same direction.

[0051] Optionally, the drive module may be a drive module of model NR0618C produced by NARI Relay Protection Electric Co., Ltd., and the adapter may be an adapter of model NR0665EXT1A or NR0665EXT1B produced by NARI Relay Protection Electric Co., Ltd.

[0052] In order to prevent backflow, one end of the two driving modules 210 is installed on the radiator 204 of the two IGBT201 of the same valve group 2 through a metal bracket 212, and the other end is installed on the radiator 204 of the two IGBT201 of another valve group 2 through a metal bracket 212 and an insulating spacer 213.

[0053] The end directly connected to the heat sink 204 through the metal bracket 212 can make the driving module 210 and the heat sink 204 have the same potential, while the end installed through the metal bracket 212 and the insulating spacer 213 achieves insulation between the two to prevent the formation of a current loop on the driving module 210.

[0054] In order to provide electric energy to the driving module 210 , a pair of power supply coils 214 are provided on the valve string 2 at the end, and the power supply coils 214 are respectively connected to the two driving modules 210 .

[0055] In order to supply energy to the bypass switch assembly 4, each bypass switch assembly 4 also includes a bypass switch energy supply coil 402 arranged on one side of the bypass switch 401, and a control module 403 arranged on the other side of the bypass switch 401. The bypass switch 401 is connected to the control module 403, and the control module 403 is connected to the bypass switch energy supply coil 404.

[0056] The bypass switch power supply coil 402 provides power to the control module 403 , and the control module 403 is used to control the on and off of the bypass switch 401 .

[0057] Specifically, a plurality of sunken U-shaped frames 103 are arranged between the two C-shaped insulating beams 101 at the bottom, and the bypass switch 401 , the bypass switch power supply coil 402 and the control module 403 are all installed on the U-shaped frames 103 .

[0058] The bypass switch 401 plays a protective role on the IGBT 201 , so it is connected in parallel with two IGBTs 201 in the same direction. The bypass switch 401 is connected to the copper busbar I 209 in parallel with the IGBTs 201 in the same direction through the copper busbar II 404 .

[0059] Specifically, the two copper bars II 404 on the bypass switch 401 are connected to the two copper bars I 209 for parallel connection of the same-direction IGBT 201 in a one-to-one correspondence, thereby achieving parallel connection with the IGBT 201 .

[0060] In order to facilitate the connection of an external high-voltage power supply and a low-voltage power supply, an external power supply connection copper bus 215 is provided between two IGBTs 201 of the same direction.

[0061] Specifically, the external power connection copper bar 215 is respectively connected to the copper bar I 209 near the clamping end plate 202. The external power connection copper bar 215 located on the forward IGBT side is used to connect the high voltage power supply, and the external power connection copper bar 215 located on the reverse IGBT side is used to connect the low voltage power supply.

[0062] The working principle of the DC circuit breaker equivalent valve group disclosed in the present invention is as follows:

[0063] Due to the unidirectional current conduction property of diode 303, when the forward current is turned on, the current passes through all IGBT201 and the RCD circuit in parallel with the forward IGBT, but does not flow through the RCD circuit in parallel with the reverse IGBT; when the reverse current is turned on, the current passes through all IGBT201 and the RCD circuit in parallel with the reverse IGBT, but does not flow through the RCD circuit in parallel with the forward IGBT, thereby achieving bidirectional flow.

[0064] When the equivalent valve group is working normally, the bypass switch 401 is in the open state, and the current passes through the IGBT201. When the equivalent valve group fails, that is, the fault current exceeds the tolerance current, the bypass switch 401 is closed, and the fault current is discharged through the bypass switch 401, thereby protecting the IGBT201.

[0065] Specifically, when the current of one of the forward IGBTs exceeds the tolerance current or the currents of both forward IGBTs exceed the tolerance current, the bypass switch 401 connected in parallel will be closed to short-circuit the paths of the two IGBTs 201. The same is true for the reverse IGBT.

[0066] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A DC circuit breaker equivalent valve group, characterized in that: The invention comprises a support (1), a valve string (2), an RCD component (3) and a bypass switch component (4) mounted on the support (1), wherein the valve string (2) comprises two valve strings, and each valve string (2) comprises a forward IGBT and a reverse IGBT connected in series, and two IGBTs (201) arranged in the same direction in the two valve strings (2) are connected in parallel, the RCD component (3) comprises two groups, respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of RCD components comprises a capacitor (301), a resistor (302) and a diode (303), and the capacitor (301) is connected in series with the resistor (302) and then connected in parallel with the diode (303), and the bypass switch component (4) comprises two groups, respectively connected in parallel with the forward IGBT and the reverse IGBT, and each group of bypass switch components (4) comprises a bypass switch (401); The support (1) comprises two C-shaped insulating beams (101) with upper and lower openings facing each other and arranged in pairs, two valve strings (2) are installed in parallel between the two pairs of C-shaped insulating beams (101), the RCD assembly (3) is arranged on the outside of one of the valve strings (2), and the bypass switch assembly (4) is arranged in a sunken manner below the valve string (2); Two groups of RCD components (3) are symmetrically arranged at one end of the bracket (1), wherein two capacitors (301) are mounted on a C-shaped insulating beam (101) located below via a U-shaped seat (304); When installed, the valve string (2) and the RCD assembly (3) do not extend beyond the end of the C-shaped insulating beam (101), and the position of at least one capacitor (301) does not extend beyond the side of the C-shaped insulating beam (101).

2. The DC circuit breaker equivalent valve assembly according to claim 1, characterized in that: Universal wheels (102) are respectively installed at both ends of the two C-shaped insulating beams (101) located at the bottom.

3. The DC circuit breaker equivalent valve assembly according to claim 1, characterized in that: Two IGBTs (201) of the same direction are connected in parallel via copper busbar I (209).

4. The DC circuit breaker equivalent valve assembly according to claim 1, characterized in that: A pair of drive modules (210) is arranged above the valve string (2), and each drive module (210) is respectively connected to two adapters (211), and the adapter (211) connected to the same drive module (210) is connected to two IGBTs (201) of the same direction.

5. The DC circuit breaker equivalent valve assembly according to claim 4, characterized in that: One end of the two driving modules (210) is mounted on the heat sink (204) of two IGBTs (201) of the same valve group (2) through a metal bracket (212), and the other end is mounted on the heat sink (204) of two IGBTs (201) of another valve group (2) through a metal bracket (212) and an insulating spacer (213).

6. The DC circuit breaker equivalent valve assembly according to claim 4, characterized in that: A pair of energy supply coils (214) are provided on the valve string (2) at the end, and the energy supply coils (214) are respectively connected to the two drive modules (210).

7. The DC circuit breaker equivalent valve assembly according to claim 1, characterized in that: Each bypass switch assembly (4) further comprises a bypass switch power supply coil (402) arranged on one side of the bypass switch (401), and a control module (403) arranged on the other side of the bypass switch (401), wherein the bypass switch (401) is connected to the control module (403), and the control module (403) is connected to the bypass switch power supply coil (401).

8. The DC circuit breaker equivalent valve assembly according to claim 3, characterized in that: The bypass switches (401) are connected to the copper busbars I (209) connected in parallel with the IGBTs (201) in the same direction through the copper busbars II (404).

9. The DC circuit breaker equivalent valve assembly according to claim 1, characterized in that: An external power supply connection copper busbar (215) is arranged between two IGBTs (201) of the same direction.

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