CN202059315U - Middle-voltage current transformer power busbar structure - Google Patents

Abstract

The utility model discloses a power busbar structure of a medium-voltage converter, which comprises a PCB board, a voltage equalizing resistor, a grounding resistor and a plurality of capacitors, the capacitors are detachably fixed on the PCB board and electrically connected with the PCB board, and the PCB board A detection terminal for merging voltage detection lines is provided, and the voltage equalizing resistor, the grounding resistance and the detection terminal are all electrically connected to the capacitor through the PCB board. The utility model solves the problems of complex assembly, excessive busbar loop and excessive busbar loop caused by the existing copper bar connection capacitor and too many cables in the entire busbar structure by using the PCB board to connect the capacitor, the voltage equalizing resistor, the grounding resistor and the detection terminal. Therefore, a medium-voltage converter power busbar structure with reasonable layout, high assembly efficiency, small busbar loop, and heat generation by voltage equalizing resistors that does not directly affect the capacitor insulation skin is provided.

Description

A medium-voltage converter power busbar structure

technical field

The utility model relates to a power unit of a medium-voltage converter, in particular to a capacitor busbar structure of the power unit of the medium-voltage converter.

Background technique

The medium-voltage converter power unit is a core component in the complete set of converter equipment, and the capacitor busbar structure of the power unit is a key factor affecting product performance. At present, as shown in FIG. 1 , the capacitor busbar structures in small-capacity power units mostly realize the series-parallel connection of capacitors 4 by cascading copper bars 11 and cables 9 and 10 . A large number of voltage-balancing resistors 2 are fixed on the copper bar 11. The function of the voltage-balancing resistors 2 in the structure of the capacitor busbar is to balance the voltages on both ends of each capacitor, so as to avoid the unequal equivalent DC resistance caused by the leakage current of the capacitors, which will lead to The phenomenon that the voltage across the capacitor 4 is not equal. The value of the equalizing resistor 2 is usually much smaller than the equivalent DC resistance of the capacitor 4 . The grounding resistor 3 requires an additional bracket to be fixed on the casing, and three cables are required to be connected to the capacitor terminals as the connecting wire 10 , and four cables are required to be used as the detection wires 9 to connect to the capacitor terminals for voltage detection.

This structure requires a large number of cables, and too many cables are not easy to bind and are messy. On the one hand, the space occupied by the busbar structure increases, and on the other hand, the assembly process is complicated and time-consuming, which affects assembly efficiency. At the same time, too many cable connections also make the busbar loop of the structure very large. In addition, during the working process of the converter, the grading resistor generates heat for a long time. Since it is directly fixed on the copper bar and the heat is transferred to the capacitor, it will cause the insulation skin of the capacitor to age and cause safety risks.

Utility model content

The technical problem to be solved by the utility model is to provide a reasonable layout for the current capacitor busbar structure using copper bars to connect capacitors, complex assembly caused by too many cables, too large busbar loops, and too much space. , high assembly efficiency, small busbar loop, and the heat generated by the equalizing resistors does not directly affect the power busbar structure of the capacitor insulation skin.

The problem to be solved by the utility model is realized through the following technical scheme: construct a medium-voltage converter power busbar structure, which includes a PCB board, a voltage equalizing resistor, a grounding resistor and a plurality of capacitors, and the capacitors are detachably fixed on The PCB board is electrically connected with the PCB board. The PCB board is provided with detection terminals for merging voltage detection lines. The voltage equalizing resistors, grounding resistors and detection terminals are all electrically connected to the capacitor through the PCB board.

In the above medium voltage converter power busbar structure, the capacitors are connected in series or in parallel through the copper foil provided on the PCB.

In the above medium voltage converter power busbar structure, guide holes are provided on the PCB, and the capacitors are fixed in the guide holes of the PCB through capacitor terminals.

In the above medium-voltage converter power busbar structure, the capacitor terminals are studs with threaded holes, and the studs are inserted into the guide holes and fixed on the PCB board by screws.

In the above medium voltage converter power busbar structure, the capacitors on the PCB are arranged in a linear, circular or array form.

In the above medium voltage converter power busbar structure, the voltage equalizing resistors and grounding resistors are welded on the PCB.

In the above-mentioned power busbar structure of the medium-voltage converter, the capacitor, the voltage equalizing resistor and the grounding resistor are separately arranged on different board surfaces of the PCB.

In the above medium voltage converter power busbar structure, a detection terminal is provided on the PCB, and the detection terminal and the capacitor are respectively located on different board surfaces of the PCB.

In the above medium-voltage converter power busbar structure, the capacitor is arranged in the middle of the PCB, the detection terminal is arranged at the end of the PCB, and the voltage equalizing resistor and the grounding resistor are located on the same board of the PCB. edges on both sides of the face.

In the above medium voltage converter power busbar structure, the voltage equalizing resistors and grounding resistors are electrically connected to the PCB board through cables or directly connected to the cable terminals set up on the capacitor terminals.

Implementing the power busbar structure of the medium-voltage converter of the present utility model has the following beneficial effects: PCB boards are used in the capacitor busbar structure, and the series and parallel connections between capacitors are realized by replacing copper bars with PCB boards. The detection terminal on it replaces the detection line to realize voltage detection, which effectively reduces the number of cables in the busbar structure, further optimizes the layout of the busbar structure, and reduces the busbar loop; Capacitor connection avoids the heat generated by the equalizing resistor from directly affecting the capacitor insulation skin. Therefore, the time required for the assembly of the utility model can be significantly reduced during the implementation process, and the assembly efficiency is improved. At the same time, the heat generated by the grading resistor will not directly affect the insulating skin of the capacitor, which reduces the risk of safety regulations.

Description of drawings

The utility model will be further described below in conjunction with accompanying drawings and embodiments.

FIG. 1 is a structural schematic diagram of a power busbar structure of a medium-voltage converter in the prior art;

Fig. 2 is a schematic structural diagram of a power busbar structure of a medium-voltage converter according to an embodiment of the present invention.

Detailed ways

As shown in FIG. 2 , a power busbar structure of a medium voltage converter includes a PCB board 1 , a voltage equalizing resistor 2 , a grounding resistor 3 and a plurality of capacitors 4 . The PCB board 1 is a support for electronic components and also a provider of electrical connections between components. In this embodiment, the capacitors 4 are connected in series and parallel with each other through the copper foil provided on the PCB 1 , and the capacitors 4 are electrically connected to the voltage equalizing resistor 2 and the grounding resistor 3 respectively. The PCB board 1 is also provided with detection terminals 5 for merging voltage detection lines. Detection terminals 5 can be set up on both sides of the PCB board 1 , and at least one detection terminal 5 can be set up. In the busbar structure of this embodiment, the position of the detection terminal 5 is related to the outlet position of the power cable, which further affects the layout of the entire busbar structure and the size of the busbar loop. In order to optimize the outlet position of the power cable and reduce the busbar loop, only one detection terminal 5 is set up in this embodiment, and the detection terminal 5 and the capacitor 4 are separately arranged on different board surfaces of the PCB board 1, and the detection terminal 5 passes through The copper foil arranged on the PCB 1 is electrically connected to the capacitor 4 .

The equalizing resistor 2, the grounding resistor 3 and the capacitor 4 are necessary components in the capacitor busbar structure. In this embodiment, the voltage equalizing resistor 2 and the grounding resistor 3 are welded on the PCB 1 , and the capacitor 4 is fixed in the guide hole 7 of the PCB 1 through a capacitor terminal (not shown in the figure). The capacitor terminals are studs with threaded holes, and the studs are inserted into the guide holes 7 and fixed on the PCB 1 by screws 6 . The guide hole 7 is set up on the PCB board 1, the inner wall and its upper and lower edges are all provided with a conductive layer or a through hole coated with a conductive material. In this embodiment, the guide hole 7 and the edge are provided with copper foil for contact with the capacitor. The terminals are electrically connected, the guide hole 7 communicates with the copper foil arranged on the PCB 1 , and the capacitor terminal is electrically connected to the PCB 1 through the guide hole 7 . Both sides of the board surface of the PCB board 1 can be connected to the above-mentioned components, and the board surface where the components are located is related to the rationalization of the entire busbar structure. In this embodiment, the capacitor 4, the voltage equalizing resistor 2 and the grounding resistor 3 are respectively Located on different sides of PCB board 1.

In addition, the positions of the voltage equalizing resistor 2, the grounding resistor 3 and the detection terminal 5 on the PCB 1 can be adjusted according to actual needs. The position on the PCB board 1 does not affect the implementation effect of the power busbar structure of the present invention. In this embodiment, the detection terminal 5 is located on the same board surface of the PCB board 1 as the voltage equalizing resistor 2 and the grounding resistor 3, wherein the detection terminal 5 is arranged at the end of the PCB board 1, and the voltage equalizing resistor 2 and the grounding resistor 3 are welded on The side of the same board surface of PCB board 1.

In the actual application process, the number and arrangement of capacitors in the power busbar structure of the medium-voltage converter are determined by the busbar load of the converter and the positional relationship between the busbar and other components in the converter. The utility model uses the PCB board 1 to realize the connection of the capacitors 4. When the quantity and arrangement of the capacitors 4 change, the length and shape of the PCB board 1 are adjusted accordingly to achieve the implementation effect of the utility model. Capacitors can be arranged in a linear, circular or array form. The linear arrangement includes straight lines and curves. The circular arrangement includes circular, elliptical, polygonal arrangements, etc. The array arrangement can be arranged in rows and columns according to actual needs. For example, when the capacitors 4 in the busbar structure are arranged in a straight line, the PCB board 1 is a straight line with a certain width; when the capacitors 4 are arranged in a square shape, the PCB board 1 is square; when the capacitors 4 are arranged in a triangle, the PCB The board 1 is a triangle; when the capacitors 4 are arranged in an array, the PCB board 1 is in the shape of a corresponding array. In this embodiment, the capacitors 4 are arranged in a straight line, and correspondingly, the shape of the PCB board 1 is in a straight line. In addition, the capacitor terminals can be arranged at any angle on the PCB 1 , and the above-mentioned angle refers to the angle between the connection line of the two capacitor terminals of the capacitor 4 and any side of the PCB 1 . According to the arrangement angle of the capacitor terminals on the PCB board 1, guide holes 7 are set at the corresponding positions of the PCB board 1, and then the capacitor terminals can be fixed on the PCB board 1 by screws 6, so as to realize the connection between the PCB board 1 and the capacitor 4 Fixed connection. For example, in this embodiment, the capacitor terminals of the two-end capacitor 4 are vertically arranged parallel to the ends of the PCB 1, and the capacitor terminals of the middle capacitor 4 are horizontally arranged parallel to the side of the PCB 1; the guide holes on the PCB 1 7 is also arranged in a corresponding manner, the guide holes 7 at both ends are arranged vertically parallel to the end of the PCB 1 , and the guide holes 7 in the middle are arranged horizontally parallel to the side of the PCB 1 .

In another embodiment of the present utility model, the PCB board 1 is still used for the electrical connection of multiple capacitors 4, and the voltage equalizing resistor 2 and the grounding resistor 3 are not fixed on the PCB board, but are fixed by the casing, that is, The voltage equalizing resistor 2 and the grounding resistor 3 are fixed on the casing, electrically connected to the PCB board 1 through the cable, and further electrically connected to the capacitor 4 through the PCB board 1, and can also be directly connected to the cable terminal 8 through the cable, so that The electric connection with the capacitor 4 is realized, and the cable terminal 8 is established on the capacitor terminal and electrically connected with the capacitor. Other components are connected the same as above.

Further, in another embodiment of the present utility model, the PCB board 1 is still used for the electrical connection of multiple capacitors 4, and the voltage equalizing resistor 2 is welded on the PCB board 1, and is electrically connected to the capacitor 4 through the PCB board 1, but the grounding resistance 3. Use the method of fixing the case, fix it at other positions of the medium-voltage converter, and then connect it to the PCB board 1 through the cable, and electrically connect it to the capacitor 4 through the PCB board 1. The grounding resistor 3 can also be directly connected to the capacitor 4 through the cable. The cable terminal 8 is electrically connected to realize the electrical connection with the capacitor 4 . Other components are connected the same as above.

In addition, in another embodiment of the present utility model, the PCB board 1 is still used for the electrical connection of multiple capacitors 4, the grounding resistor 3 is welded on the PCB board 1, and is electrically connected to the capacitor 4 through the PCB board 1, but the voltage equalizing resistor 2. Use the method of fixing the casing, fix it at other positions of the medium voltage converter, and then connect it to the PCB board 1 through the cable, and electrically connect it to the capacitor 4 through the PCB board 1. The voltage equalizing resistor 2 can also be directly connected to the It is electrically connected with the cable terminal 8 to realize the electrical connection with the capacitor 4 . Other components are connected the same as above.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements or improvements made within the spirit and principles of the present utility model shall be included in the scope of the present utility model. within the scope of protection. 7

Claims (10)

1. A medium-voltage converter power busbar structure, comprising a voltage equalizing resistor, a grounding resistor and a plurality of capacitors, characterized in that it also includes a PCB board, and the capacitor is detachably fixed on the PCB board and electrically connected to the PCB board connection, the PCB board is provided with detection terminals for merging voltage detection lines, and the voltage equalizing resistors, grounding resistors and detection terminals are all electrically connected to capacitors through the PCB board. 2. The power busbar structure of the medium-voltage converter according to claim 1, wherein the capacitors are connected in series or in parallel through copper foils provided on the PCB. 3 . The power busbar structure of a medium voltage converter according to claim 1 , wherein a guide hole is provided on the PCB, and the capacitor is fixed in the guide hole of the PCB through a capacitor terminal. 4 . 4. The power busbar structure of a medium-voltage converter according to claim 3, wherein the capacitor terminal is a stud with a threaded hole, and the stud is inserted into the guide hole and passed through the screw. Fixed on the PCB board. 5. The power busbar structure of the medium-voltage converter according to claim 1, wherein the capacitors on the PCB are arranged in a linear, circular or array form. 6. The power busbar structure of a medium-voltage converter according to any one of claims 1-5, wherein the voltage equalizing resistors and grounding resistors are welded on the PCB. 7 . The power busbar structure of the medium voltage converter according to claim 6 , wherein the capacitor, the voltage equalizing resistor and the grounding resistor are separately arranged on different board surfaces of the PCB. 8 . 8. The power busbar structure of a medium-voltage converter according to claim 6, wherein a detection terminal is provided on the PCB, and the detection terminal and the capacitor are respectively located on different board surfaces of the PCB. superior. 9. The power busbar structure of a medium-voltage converter according to claim 6, wherein the capacitor is arranged in the middle of the PCB, the detection terminal is arranged at the end of the PCB, and the voltage equalization Resistors and grounding resistors are located on both edges of the same board surface of the PCB. 10. The power busbar structure of a medium-voltage converter according to any one of claims 1-5, wherein the voltage equalizing resistors and grounding resistors are electrically connected to the PCB board through cables or directly connected to capacitor terminals The cable terminals are established for electrical connection.

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