CN214380646U - Current conversion system - Google Patents
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- CN214380646U CN214380646U CN202120582484.0U CN202120582484U CN214380646U CN 214380646 U CN214380646 U CN 214380646U CN 202120582484 U CN202120582484 U CN 202120582484U CN 214380646 U CN214380646 U CN 214380646U
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- 238000006243 chemical reaction Methods 0.000 title claims abstract description 54
- 238000010586 diagram Methods 0.000 description 8
- 230000003139 buffering effect Effects 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 238000013016 damping Methods 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
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Abstract
The utility model discloses a current conversion system, current conversion system includes: the converter valve group comprises a plurality of converter valve groups, wherein a plurality of frequency conversion units are arranged in each converter valve group; the first end of the frequency conversion unit is connected with a first buffer element, and the first buffer element is connected with the first end of the converter valve group; the first end of the converter valve group is used for being connected with a first alternating current system, the second end of the converter valve group is used for being connected with a second alternating current system, and a second buffer element is arranged between the converter valve group and the second alternating current system. The utility model discloses an all connect the buffer device in converter valve outside and the inside frequency conversion unit side of converter valve, can restrain the inside circulation of converter valve and outside heavy current simultaneously, guarantee the normal work of converter valve.
Description
Technical Field
The utility model relates to a power electronic technology field, concretely relates to current conversion system.
Background
The flexible low-frequency alternating current transmission system flexibly selects a proper frequency of 0-50 Hz by means of frequency conversion of power electronics and a power grid regulation and control technology, enhances the flexible regulation and control capability of the power grid, improves the transmission capacity of the power grid, and makes up for the defects of power frequency alternating current and direct current transmission modes. An AC-AC frequency converter in the flexible low-frequency AC power transmission system can realize frequency conversion and simultaneously can carry out flexible control on power flow regulation, voltage regulation and the like on a power grid, and is core equipment of the system. However, the IGBT valves in the converter have limited voltage withstand capability, and when the converter works, the IGBT valves may be broken down by the circulation current caused by energy imbalance among the phases, so a converter system is urgently needed to suppress the circulation current and ensure the normal operation of the converter valve.
SUMMERY OF THE UTILITY MODEL
Therefore, the to-be-solved technical problem of the present invention is to overcome the defect that the IGBT valve may be broken down by the circulation caused by the unbalanced direct capability of each phase of the converter valve in the prior art, thereby providing a converter system.
According to a first aspect, the utility model discloses a current conversion system, include: the converter valve group comprises a plurality of converter valve groups, wherein a plurality of frequency conversion units are arranged in each converter valve group; the first end of the frequency conversion unit is connected with a first buffer element, and the first buffer element is connected with the first end of the converter valve group; the first end of the converter valve group is used for being connected with a first alternating current system, the second end of the converter valve group is used for being connected with a second alternating current system, and a second buffer element is arranged between the converter valve group and the second alternating current system.
Optionally, a third buffer element is disposed between the converter valve group and the first ac system.
Optionally, a second end of the frequency conversion unit is connected to a fourth buffering element, and the fourth buffering element is connected to a second end of the converter valve group.
Optionally, the number of the converter valve groups is three, and the converter valve groups are connected with the second ac system through three second buffer elements.
Optionally, the number of the converter valve groups is three, and the three converter valve groups are connected with the second ac system through one second buffer element.
Optionally, the number of the converter valve groups is three, and the converter valve groups are connected with the first ac system through three third buffer elements.
Optionally, the number of the converter valve groups is three, and the three converter valve groups are connected to the first ac system through one third buffer element.
Optionally, the number of the frequency conversion units of each converter valve group is three, the second end of each frequency conversion unit is connected to the second buffer element, and the first buffer elements of each converter valve group are connected to the first ac system after being connected to each other.
Optionally, the number of the frequency conversion units of each converter valve group is three, the second end of the frequency conversion unit of each converter valve group is connected to the second buffer element after being connected to each other, and each first buffer element is connected to the first ac system.
Optionally, the second buffer element is a reactance, and the first buffer element comprises: reactance and transformer.
The utility model discloses technical scheme has following advantage:
the utility model provides a current conversion system, include: the converter valve group comprises a plurality of converter valve groups, wherein a plurality of frequency conversion units are arranged in each converter valve group; the first end of the frequency conversion unit is connected with a first buffer element, and the first buffer element is connected with the first end of the converter valve group; the first end of the converter valve group is used for being connected with a first alternating current system, the second end of the converter valve group is used for being connected with a second alternating current system, and a second buffer element is arranged between the converter valve group and the second alternating current system. The utility model discloses an all connect the buffer device in converter valve outside and the inside frequency conversion unit side of converter valve, can restrain the inside circulation of converter valve and outside heavy current simultaneously, guarantee the normal work of converter valve.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic diagram of a first structure of a commutation system in an embodiment of the present invention;
fig. 2 is a schematic diagram of a second structure of a current converting system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a third structure of a current converting system according to an embodiment of the present invention;
fig. 4 is a fourth schematic structural diagram of a current converting system according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a fifth structure of a current converting system according to an embodiment of the present invention;
fig. 6 is a sixth schematic structural diagram of a current converting system according to an embodiment of the present invention;
fig. 7 is a seventh schematic structural diagram of a current converting system according to an embodiment of the present invention;
fig. 8 is an eighth schematic structural diagram of a commutation system in an embodiment of the present invention.
Reference numerals:
10-a converter valve group; 101-a frequency conversion unit; 20-a first cushioning element;
30-a second communication system; 40-a first communication system; 50-a second cushioning element;
60-a third cushioning element; 70-fourth cushioning element.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.
The embodiment of the utility model discloses change of current system, as shown in fig. 1 or fig. 2, include:
a plurality of converter valve sets 10, wherein each converter valve set 10 is internally provided with a plurality of frequency conversion units 101; the first end of the frequency conversion unit 101 is connected with the first buffer element 20, and the first buffer element 20 is connected with the first end of the converter valve group 10; the converter valve group 10 has a first end for connecting to the first ac system 40 and a second end for connecting to the second ac system 30, and a second buffer element 50 is disposed between the converter valve group 10 and the second ac system 30.
Illustratively, the converter valve group 10 may be a cascaded full-control H-bridge module, the number of the converter valve groups is 3, and the number of the frequency conversion units 101 in each converter valve group 10 is also 3. The first damping element 20 may be a reactor, and the second damping element 50 may be a reactor, or may be a transformer, wherein the transformer may be a three-phase transformer, or may be a plurality of single-phase transformers. When the second snubber element 50 is a three-phase transformer, the secondary windings of the three-phase transformer may be connected in series or in parallel. The embodiment of the utility model provides a do not specifically prescribe a limit to the connection method of the secondary winding of this second buffer element, transformer and three-phase transformer, and technical personnel in the field can confirm according to the actual conditions of commutation system.
The first ac system 40 may be a commercial frequency system (i.e., an ac power having a frequency of 50 HZ) or a low frequency system (i.e., a low frequency ac power having a frequency of 0-49 HZ). The second ac system 30 may also be a main frequency system or a low frequency system. When the first ac system 40 is a power frequency system, the second ac system 30 is a low frequency system, and when the first ac system 40 is a low frequency system, the second ac system 30 is a power frequency system. The embodiment of the utility model provides a do not specifically and restrict to the specific frequency value of this first alternating current system, second alternating current system and low frequency, and this field can be confirmed according to the actual demand.
The first snubber element 20, the second snubber element 50, the first ac system 40, the second ac system 30, the converter valve group 10, and the inverter unit 101 are connected to each other by power transmission cables.
In the embodiment of the present invention, as shown in fig. 1, the number of the frequency conversion units 101 of each converter valve group 10 is three, the second end of each frequency conversion unit 101 is connected to the second buffer element 50, and the first buffer element 20 of each converter valve group 10 is connected to the first ac system 40 after being connected to each other, that is, each converter valve group 10 is connected to the first ac system 40 as a whole.
Specifically, one line of the frequency conversion unit 101 may be randomly picked up in each converter valve group 10 as the a phase, the B phase and the C phase of the output line of the converter valve group 10, and the a phase, the B phase and the C phase of the output line of each converter valve group 10 are different. As shown in fig. 3, for example, the first frequency conversion unit 101 line of the first converter valve group 10, the first frequency conversion unit 101 line of the second converter valve group 10, and the first frequency conversion unit 101 line of the third converter valve group 10 may be used as the a phase, the B phase, and the C phase of the output line of one converter valve group, the second frequency conversion unit 101 line of the first converter valve group 10, the second frequency conversion unit 101 line of the second converter valve group 10, and the second frequency conversion unit 101 line of the third converter valve group 10 may be used as the a phase, the B phase, and the C phase of the output line of one converter valve group, and the third frequency conversion unit 101 line of the first converter valve group 10, the third frequency conversion unit 101 line of the second converter valve group 10, and the third frequency conversion unit 101 line of the third converter valve group 10 may be used as the a phase, the B phase, and the C phase of the output line of one converter valve group. The embodiment of the utility model provides a do not do specifically and restrict this combination method, technical personnel in the field can be confirmed according to the actual demand, as long as guarantee that the three-phase among each output line of converter valve group 10 comes from different converter valve groups.
In the embodiment of the present invention, as shown in fig. 2, the number of the frequency conversion units 101 of each of the converter valve sets 10 is three, the second ends of the frequency conversion units 101 of each of the converter valve sets 10 are connected to each other and then connected to the second buffer element, and each of the first buffer elements is connected to the first ac system 40 respectively. For a specific embodiment, refer to the description of the corresponding steps, which is not repeated herein.
The utility model provides a current conversion system, include: the converter valve group comprises a plurality of converter valve groups, wherein a plurality of frequency conversion units are arranged in each converter valve group; the first end of the frequency conversion unit is connected with a first buffer element, and the first buffer element is connected with the first end of the converter valve group; the first end of the converter valve group is used for being connected with a first alternating current system, the second end of the converter valve group is used for being connected with a second alternating current system, and a second buffer element is arranged between the converter valve group and the second alternating current system. The utility model discloses an all connect the buffer device in converter valve outside and the inside frequency conversion unit side of converter valve, can restrain the inside circulation of converter valve and outside heavy current simultaneously, guarantee the normal work of converter valve.
As an optional implementation manner of the embodiment of the present invention, for better protecting the converter valve group 10, a buffer element may be further disposed between the converter valve group 10 and the first ac system 40, specifically, as shown in fig. 4, the first end of the frequency conversion unit 101 is connected to the first buffer element 20, the first buffer element 20 is connected to the first end of the converter valve group 10, the first end of the converter valve group 10 is used for connecting the first ac system 40, specifically, the third buffer element 60 is disposed between the converter valve group 10 and the first ac system 40, the first end of the converter valve group 10 is connected to the first end of the third buffer element 60, and the second end of the third buffer element 60 is connected to the first ac system 40. The second end of the converter valve group 10 is used for connecting with the second ac system 30, and a second buffer element 50 is arranged between the converter valve group 10 and the second ac system 30. The third buffer element may be a reactance, a single-phase transformer, or a three-phase transformer. The embodiment of the present invention does not specifically limit the third buffer element, and those skilled in the art can determine the third buffer element according to actual situations.
As an optional implementation manner of the embodiment of the present invention, for better protecting the converter valve set, a buffer element may be connected to the second end of the frequency conversion unit 101, specifically, as shown in fig. 5 or fig. 6, the second end of the frequency conversion unit 101 is connected to the fourth buffer element 70, and the fourth buffer element 70 is connected to the second end of the converter valve set 10. The fourth damping element may also be reactive.
In an embodiment of the present invention, the total impedance of the buffer connecting the first ac system 40 and the second ac system 30 is in a range of 5% -20%, typically 10%, of the reference impedance of the first ac system 40 and the second ac system 30. For example, the reference impedance of the commutation system is Zsb, the reference impedance may be calculated according to the frequencies of the first ac system 40 and the second ac system 30, the calculated reference impedances at different frequencies are different, and the lower the frequency is, the lower the reference impedance is, the calculation method of which is the prior art and is not described again. When the equivalent impedance of the first buffer element 20 is Z1, the equivalent impedance of the second buffer element 50 is Z2, the equivalent impedance of the third buffer element 60 is Z3, and the equivalent impedance of the fourth buffer element 70 is Z4, the total buffer impedance of the commutation system is Z1+ Z2+ Z3+ Z4 is 0.05Zsb to 0.2 Zsb. The embodiment of the utility model provides an in, can calculate the upper limit and the lower limit value of total impedance respectively, can select in the scope of upper limit and lower limit value by actual demand.
It should be noted that the method for calculating the total buffer impedance of the topology structure of other commutation systems is the same as the above method, and is not described herein again.
As an optional implementation manner of the embodiment of the present invention, as shown in fig. 7, the number of the converter valve sets 10 is 3, the converter valve sets 10 are connected to the second ac system 30 through three second buffer elements 50, that is, each converter valve set 10 is connected to one end of one second buffer element 50, the other end of the second buffer element 50 is connected to the second ac system 30, in order to reduce the number of reactances, the embodiment of the present invention can also connect three converter valve sets 10 to the second ac system 30 through one second buffer element 50.
As an optional implementation manner of the embodiment of the present invention, as shown in fig. 8, the number of the converter valve sets 10 is 3, the converter valve sets 10 are connected to the first ac system 40 through three third buffering elements 60, each converter valve set 10 is connected to one end of one third buffering element 60 respectively, the other end of the third buffering element 60 is connected to the first ac system 40, in order to reduce the number of reactances, the embodiment of the present invention can also connect three converter valve sets 10 to the first ac system 40 through one third buffering element 60.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.
Claims (10)
1. A commutation system, comprising:
the converter valve group comprises a plurality of converter valve groups, wherein a plurality of frequency conversion units are arranged in each converter valve group; the first end of the frequency conversion unit is connected with a first buffer element, and the first buffer element is connected with the first end of the converter valve group; the first end of the converter valve group is used for being connected with a first alternating current system, the second end of the converter valve group is used for being connected with a second alternating current system, and a second buffer element is arranged between the converter valve group and the second alternating current system.
2. The converter system according to claim 1, wherein a third buffer element is provided between said set of converter valves and said first ac system.
3. The converter system according to claim 1 or 2, wherein the second end of said frequency conversion unit is connected to a fourth buffer element, said fourth buffer element being connected to the second end of said group of converter valves.
4. The converter system according to claim 1, wherein said set of converter valves is three in number, and said set of converter valves is connected to said second ac system through three of said second buffer members.
5. The converter system according to claim 1, wherein said number of said set of converter valves is three, and three of said set of converter valves are connected to said second ac system through one of said second buffer members.
6. The converter system according to claim 2, wherein said set of converter valves is three in number, and said set of converter valves is connected to said first ac system through three of said third buffer members.
7. The converter system according to claim 2, wherein said number of said set of converter valves is three, and three of said set of converter valves are connected to said first ac system through one of said third snubber members.
8. The converter system according to claim 1, wherein the number of the frequency conversion units of each of the converter valve groups is three, the second end of each of the frequency conversion units is connected to the second buffer element, and the first buffer elements of each of the converter valve groups are connected to the first ac system after being connected to each other.
9. The converter system according to claim 1, wherein the number of the frequency conversion units of each of said converter valve groups is three, the second ends of the frequency conversion units of each of said converter valve groups are connected to each other and then to said second buffer element, and each of said first buffer elements is connected to said first ac system, respectively.
10. A converter system according to claim 1, wherein said second buffer element is reactive and said first buffer element comprises: reactance and transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120582484.0U CN214380646U (en) | 2021-03-22 | 2021-03-22 | Current conversion system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120582484.0U CN214380646U (en) | 2021-03-22 | 2021-03-22 | Current conversion system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214380646U true CN214380646U (en) | 2021-10-08 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120582484.0U Active CN214380646U (en) | 2021-03-22 | 2021-03-22 | Current conversion system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214380646U (en) |
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2021
- 2021-03-22 CN CN202120582484.0U patent/CN214380646U/en active Active
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