Capacitor reactive power compensation device for test

Abstract

The utility model belongs to the technical field of capacitors, and discloses a capacitor reactive power compensation device for test, which comprises an insulating platform, a plurality of capacitors, a plurality of reactive power compensation devices and a plurality of reactive power compensation devices, and is characterized in that the bottom of the insulating platform is connected with an insulating supporting piece; the top of the capacitor is provided with sleeves, and the sleeves are connected through a connecting wire. Shells of the capacitors are connected through equipotential lines; and the bottom of the insulating supporting piece is connected with an insulating supporting column base grounding wire. According to the utility model, the space height and maintenance difficulty can be reduced. The single-layer platform type structure greatly reduces space height and maintenance difficulty, and is suitable for places with narrow space and limited height.

Description

Technical Field

[0001] This utility model belongs to the field of capacitor technology, specifically relating to a reactive power compensation device for experimental capacitors. Background Technology

[0002] When transformers and reactors undergo high-current tests, capacitors need to be connected in parallel to compensate for reactive current in the circuit, reduce reactive power consumption on the power supply side, and lower the capacity of the test power supply. For multi-layer tower structures, to facilitate external wiring, the compensation capacitors are all placed horizontally, and pneumatic disconnect switches are installed outside the tower frame to achieve multi-layer series and parallel connections. Sufficient space is required to accommodate the insulating air gaps.

[0003] Currently, the parallel capacitor reactive power compensation devices used in experiments are all tower-type placements, consisting of multiple tower layers, ranging from several to more than a dozen layers. This structure not only requires sufficient space and height but is also difficult to maintain.

[0004] Therefore, how to use parallel capacitors for reactive power compensation when space height is limited is a problem to be solved in this technical field.

[0005] Chinese patent publication number CN207732441U, entitled "A High-Voltage Parallel Capacitor Compensation Device," describes a device comprising an insulating support and a high-voltage automatic reactive power compensation box. The automatic reactive power compensation box is fixedly mounted on the upper surface of the insulating support, and a tightening bolt is provided on the upper surface of the box. The conductive end of the tightening bolt is connected to a circuit breaker via a wire. The circuit breaker is fixedly mounted on a connecting rod. The automatic reactive power compensation box also contains a parallel capacitor compensation circuit. This circuit employs a reactive power compensation device based on zero-sequence current. When protecting parallel capacitor banks, only a zero-sequence current transformer needs to be installed at the beginning of each parallel capacitor bank. By detecting the magnitude of the zero-sequence current, the faulty capacitor bank can be identified. This effectively enables rapid protection action against capacitor bank faults, reducing protection costs, simplifying protection setting calculations, and improving the operational reliability of the reactive power compensation device. However, this patent application fails to address the issues of reducing space occupation and simplifying maintenance. Utility Model Content

[0006] In order to overcome the problems existing in the prior art, the purpose of this utility model is to provide a reactive power compensation device for a test capacitor. The reactive power compensation device for a test capacitor adopts a single-layer platform structure, which enables the reactive power compensation device for a test capacitor to be arranged in a small area.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0008] This utility model provides a reactive power compensation device for a test capacitor, comprising: an insulating platform, an insulating support member connected to the bottom of the insulating platform, and a plurality of capacitors placed on the insulating platform in a single layer; the top of each capacitor has a sleeve, and the sleeves are connected to each other by wiring; the outer shells of the capacitors are connected to each other by equipotential lines; and an insulating support column base grounding wire is connected to the bottom of the insulating support member.

[0009] Optionally, the insulating support is an insulating support column, and the bottom of the insulating support has a metal base.

[0010] Optionally, the capacitor is placed vertically on the insulating platform, and the length of the insulating support is less than 2m.

[0011] Optionally, the number of insulating platforms is greater than one, and the multiple insulating platforms are arranged in multiple groups. Each group of insulating platforms is arranged linearly, and the capacitors in the same group of insulating platforms form a capacitor group. The capacitors in the same capacitor group are connected in parallel.

[0012] Optionally, the capacitor banks can be connected in a star or delta configuration to form a three-phase output, or multiple banks can be connected in parallel or in series to form a single-phase output.

[0013] Optionally, both the wiring and the equipotential line are bare copper wires.

[0014] Optionally, the insulating platform is an insulating wooden board.

[0015] Optionally, the capacitor is an oil-filled capacitor.

[0016] Optionally, the capacitance of the capacitor is 50kvar, 100kvar, 200kvar, 300kvar, or 500kvar.

[0017] Optionally, the insulating support is an insulator.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] Existing laboratory parallel capacitor compensation structures are multi-layered tower-type, requiring the use of a lifting vehicle for maintenance. This invention discloses a platform-style parallel capacitor reactive power compensation device, which reduces space height and maintenance difficulty. The single-layer platform structure of this invention significantly reduces space height and maintenance difficulty. The single-layer platform structure allows the compensation capacitors to be placed vertically, with series and parallel connections directly using wires, saving space and cost.

[0020] Furthermore, this invention is suitable for locations with limited space and height, and can be arranged in a straight line or triangular pattern according to the shape of the site, without requiring other switches and control systems. This invention can be applied to reactive power compensation in transformer and reactor product testing, and can change the connection method and the number of capacitor banks according to actual compensation needs to meet the requirements of different voltage levels and different compensation capacities. Attached Figure Description

[0021] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the present invention and do not specifically limit the shapes and proportions of the components. In the drawings:

[0022] Figure 1 This is a front view of the present utility model;

[0023] Figure 2 This is a top view of the present invention;

[0024] Figure 3 This is a schematic diagram of a three-phase Y-connected capacitor bank according to Embodiment 3 of this utility model;

[0025] Figure 4 This is a schematic diagram of a three-phase D-connected capacitor bank according to Embodiment 3 of this utility model;

[0026] Figure 5 This is a schematic diagram of a three-parallel, two-series capacitor bank according to Embodiment 3 of this utility model;

[0027] Figure 6 This is a schematic diagram of a six-parallel capacitor bank according to Embodiment 3 of this utility model;

[0028] Figure 7 This is a front view of the capacitor bank of this utility model;

[0029] Figure 8 This is a top view of the capacitor bank of this utility model;

[0030] Among them, 1. Bushing; 2. Capacitor; 3. Insulating platform; 4. Insulating support; 5. Wiring; 51. First point; 52. Second point; 53. Third point; 54. Fourth point; 55. Fifth point; 6. Equipotential line; 7. Grounding wire of insulating support column base. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0032] 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 claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] In the description of the embodiments of this utility model, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0034] When an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments. The use of the term "horizontal" does not imply that the component is required to be absolutely horizontal, but rather that it may be slightly tilted. "Horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0035] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this utility model, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0037] The present invention will now be described in detail with reference to the accompanying drawings.

[0038] This utility model discloses a reactive power compensation device for experimental capacitors, comprising: an insulating platform 3, an insulating support 4 connected to the bottom of the insulating platform 3, and a plurality of capacitors 2 placed in a single layer on the insulating platform 3; each capacitor 2 has a sleeve 1 on its top, and the sleeves 1 are connected to each other by wiring 5; the outer shells of the capacitors 2 are connected to each other by equipotential lines 6; and an insulating support column base grounding wire 7 is connected to the bottom of the insulating support 4. The capacitors 2 are placed vertically on the insulating platform 3. Optionally, the length of the insulating support 4 is less than 2m.

[0039] This utility model discloses a reactive power compensation device for a test capacitor. When in use, it includes the following steps:

[0040] Before installation, select the appropriate number of capacitors and voltage-matching insulation supports based on the compensation capacity and test voltage. The cross-sectional area of ​​the bare copper conductors should be matched with the compensation current.

[0041] During installation, capacitor 2 is placed vertically on insulating platform 3;

[0042] Connect the sleeves 1 of each capacitor 2 via wiring 5; connect the outer casing of each capacitor 2 via equipotential lines 6.

[0043] The sleeve 1 of this invention is the main insulation device for the capacitor, with the leads of the internal capacitor plates led out to the outside, ensuring insulation between the leads and between the leads and the capacitor casing, while also fixing the leads. The capacitor 2 serves as the main body of the reactive power compensation device, and multiple units can be arranged vertically on the insulating platform 3. The insulating platform 3 supports the entire capacitor. The insulating support column 4 provides potential insulation between the capacitor and the ground, ensuring the overall stability of the capacitor. The current-conducting connecting wire 5 connects the capacitors in parallel and in series, forming an effective current loop for reactive power compensation. The casing equipotential line 6 connects the capacitor casings on the same platform, ensuring they are at the same potential and preventing floating discharge. The grounding wire 7 of the insulating support column base is used to fix the potential of the metal base of the insulating support column, preventing floating.

[0044] Existing laboratory compensation capacitor structures are multi-layered towers, ranging in height from 5 to over 10 meters, requiring the use of lifting vehicles for maintenance. This invention's single-layer platform structure maintains a height below 2 meters, significantly reducing space requirements and maintenance difficulty. The single-layer platform structure allows for vertical placement of the compensation capacitors, with series and parallel connections directly using wires, saving space and cost.

[0045] Example 1

[0046] The capacitor 2 of this invention is placed vertically rather than horizontally because of space constraints. Horizontal placement would occupy too much space, making the second wiring difficult and preventing centralized wiring; furthermore, the potential distance to ground would be reduced, so vertical placement is the optimal arrangement for the capacitor. Due to the insulating characteristics of capacitor 2, the insulation level between the terminals and the casing cannot be too high, otherwise insulation breakdown will occur. Therefore, in this invention, the potential level of the casing and terminals of capacitor 2 is kept below its maximum operating voltage.

[0047] Specifically, in this invention, capacitor 2 is designed with fully insulated terminals to ensure the insulation level of the two terminals to the outer casing.

[0048] Capacitor 2 includes capacitor plates, dielectric, fuse, casing, and bushing 1. Each capacitor has two terminals. When multiple capacitors are connected in parallel or series, the capacitor terminals are connected together via conductive connecting lines and then connected to an external load. The capacitor casings are connected via equipotential lines to form an equipotential structure, preventing floating discharge.

[0049] Optionally, since the capacitor 2 of this invention is not stacked, the weight per unit projected area is greatly reduced, and a thinner and lighter insulating support 4 is used for insulating support.

[0050] Optionally, the insulating support 4 is made of composite material.

[0051] Optionally, the insulating support 4 is an insulator, which is made of a glass fiber resin core rod and an organic material sheath and skirt. Its characteristics include small size, light weight, high tensile strength, and excellent resistance to pollution flashover.

[0052] The insulating support 4 has a base at its bottom, which is made of cast iron. The insulating support 4 is fixed to the ground with bolts. The ground must be clean, level, and have sufficient strength to ensure the stability of the insulating support column. The bases of all the insulating support components 4 at the bottom are grounded through the grounding wire 7 of the insulating support column base to prevent floating potential.

[0053] Insulating platform 1 is an insulating object, so potential issues are not considered. However, the upper metal fixing component that is fixed to the insulating support needs to be connected to the capacitor shell via an equipotential line, but it cannot be grounded because the shell has a certain potential. This method is simple, reliable, and self-explanatory.

[0054] Capacitor 2, insulating platform 1, and insulating support 4 constitute a compensation unit. Multiple compensation units can be placed depending on the size of the site. The compensation units can be connected in parallel or series, and can be configured for single-phase or three-phase output. Depending on the site, they can be arranged in a triangular or linear pattern. The linear arrangement saves space, ensures sufficient insulation distance, allows the upper terminals to be directly connected to the high-voltage line, and provides support and isolation at the bottom through the insulating support, thus minimizing the size. Each compensation unit can hold multiple parallel capacitors 2, which are connected in parallel to form groups. The number of series stages in each group is determined by the insulation class of the support.

[0055] like Figure 1 As shown, when there are two outputs, the voltage is 80kV, and potential analysis is required. Figure 4 As shown, red represents 2 strings of 5-cable connecting wires, and blue represents 5-cable equipotential bonding wires for the outer casing.

[0056] When used in a two-string configuration, the ground potential at point 51 is 80kV, at point 52 it is 60kV, at point 53 it is 40kV, at point 54 it is 20kV, and at point 55 it is 0kV. Since the insulation level of insulating support 4 is 40kV, when the operating voltage is 53.3kV, the ground potential at point 52 is 40kV.

[0057] Example 2

[0058] In this embodiment, the rated voltage of each of the parallel capacitors is 20kV. An insulating wooden board of 1500mm×1100mm×40mm is selected as the platform, and six platforms are placed according to the size of the site.

[0059] During the setup, based on the compensation capacity, first determine the number of compensation capacitors, the size and weight of each capacitor, then determine the combination method and distance selection based on the existing site, then determine the size of the insulation platform to ensure appropriate area and thickness, and finally calculate the total weight. Based on the total weight, select appropriate insulation supports to ensure pressure resistance and insulation strength, in order to obtain the optimal solution for the best insulation size and weight support.

[0060] like Figure 2As shown, the platform for placing the parallel capacitors 2 consists of insulating wooden boards and supports. Based on the platform dimensions, 12 parallel capacitors 2 are placed on each platform. Insulating supports 4 with a voltage rating of 40kV are selected based on the space height. Six parallel capacitors 2 are connected in parallel to form one group, and the two groups are connected in series for output (maximum 40kV).

[0061] Before constructing the capacitor compensation platform, it is necessary to measure the dimensions of the connected high-voltage busbar to ground and the space below. Based on the volume of a single capacitor and the required insulation distance, determine the distance coefficient between adjacent capacitors (one bushing length), the distance coefficient between the upper and lower spaces (five times the bushing distance for the upper part and two times the bushing distance for the lower part), and the distance coefficient between the front and back (three times the bushing distance plus a safety distance of 0.5 meters). The calculated space is smaller than the currently available installation space, thus allowing the calculation of the number and capacity of capacitors that can be installed.

[0062] Example 3

[0063] In this embodiment, when the capacitor bank is connected in a three-phase configuration, it can output two capacitors in parallel or two capacitors in series. When connected in a single-phase configuration, it can output six capacitors in parallel or three capacitors in parallel and two capacitors in series.

[0064] like Figure 3 As shown, the capacitor bank adopts a three-phase Y-connection (40kV). Two sets of capacitor banks are placed on each insulating platform 3. The capacitor banks of the two insulating platforms 3 constitute one phase, and the capacitor banks of each phase constitute two parallel and two series connections.

[0065] like Figure 4 As shown, the capacitor bank is connected in a three-phase D-connection (40kV). Two sets of capacitor banks are placed on each insulating platform 3. The capacitor banks of the two insulating platforms 3 constitute one phase, and the capacitor banks of each phase constitute two parallel and two series connections.

[0066] Three-phase Y-connection or three-phase D-connection, using six insulated platforms 3, 72 capacitors, two insulated platforms 3 constitute one phase, divided into three phases, connected to the high-voltage bus via lead wires.

[0067] like Figure 5 As shown, the capacitor bank adopts single-phase (80kV), and two sets of capacitor banks are placed on each insulating platform 3. The two sets of capacitor banks are connected in series, and the capacitor banks of the six insulating platforms 3 form a three-parallel two-series configuration.

[0068] like Figure 6 As shown, the capacitor bank adopts single-phase (40kV), and two sets of capacitor banks are placed on each insulating platform 3. The two sets of capacitor banks are connected in series, and the capacitor banks of the six insulating platforms 3 form a six-parallel structure.

[0069] When six insulating platforms 3 are connected in parallel, all terminals on the same side are connected in parallel, thus forming a single head and tail, which can be led out to the high-voltage bus. When three are connected in parallel and two in series, the three insulating platforms 3 on the left are connected in parallel, and the three insulating platforms 3 on the right are also connected in parallel. Then, they are shorted on one side, and the terminals on the other side of each are led out to the high-voltage bus.

[0070] Taking the insulation platform 3 as a unit, three phases can form two series Y connections, two parallel Y connections, two series D connections, and two parallel D connections; single phases can form six series, five series, four series, three series two parallel connections, two series three parallel connections, and one parallel connection; the insulation platform 3 can form series and parallel connections internally to adapt to different voltage levels.

[0071] To prevent the insulating support 4 from exceeding its withstand level, a potential analysis is necessary. Taking the voltage level of the insulating support 4 selected in this embodiment as an example, when two insulating platforms 3 are connected in series (four capacitors 2 are used in series), the series voltage can reach 80kV, far exceeding the 40kV withstand level of the insulating support 4. Therefore, improving the output efficiency of the capacitor 2 without exceeding the withstand level of the insulating support 4 is extremely important. Since the rated voltage between the output terminal and the casing is 20kV, when adjacent capacitors 2 are connected in series, the output efficiency of the capacitor 2 is maximized when the casing is at the average of its lowest and highest voltages. Therefore, when the two sets of capacitors 2 on the second insulating platform 3 are connected in series, the casing voltage reaches a maximum of the 40kV withstand voltage of the insulating support 4 on the insulating platform 3. Calculations show that the 40kV casing voltage of the capacitors 2 on the second insulating platform 3 is the series voltage of three capacitors 2, meaning each stage has a voltage of 13.3kV, and the four-stage voltage is 53.3kV.

[0072] Therefore, by connecting the outer casing and the equipotential line 6, the output efficiency of capacitor 2 can be maximized while ensuring that the voltage of capacitor 2 does not exceed the rated voltage. However, if the outer casing is completely grounded, or connected to the output terminal, or connected to the second-stage capacitor terminal, the output efficiency of capacitor 2 cannot be maximized.

[0073] Due to space and economic constraints, the insulation level of the insulating support 4 is set at 40kV. The most extreme case is four single-phase capacitors 2 connected in series. Other wiring methods, due to the voltage reduction, can generally achieve 100% efficiency for capacitors 2. For example, in a three-phase configuration with two parallel and two series connections, the highest phase voltage output is 40kV, and the voltage of the casing to ground is 30kV; in a three-phase configuration with four parallel connections, the highest phase voltage output is 40kV, and the voltage of the casing to ground is 10kV; in a single-phase configuration with two parallel and three series connections, the highest phase voltage output is 60kV, and the voltage of the casing to ground is 40kV; in a single-phase configuration with three parallel and two series connections, the highest phase voltage output is 40kV, and the voltage of the casing to ground is 20kV. Under the condition of meeting full capacity output, each insulating component will not exceed its respective insulation level, achieving maximum cost-effectiveness.

[0074] This utility model, through partial circuit diagrams, clearly illustrates the composition and connection methods of the entire architecture. The six insulated platforms 3 can form three-phase Y-connections, D-connections, single-phase series, and parallel outputs. The diverse configurations allow for different combinations of current and voltage to meet the reactive power compensation needs of various types of products. Within a limited height space, it avoids the inefficiency of compensation capacity caused by insufficient insulation distance and inadequate connection methods resulting from the use of knife switches.

[0075] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the structural settings, working methods or control methods involved are all conventional settings, working methods or control methods in the art unless otherwise specified.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A reactive power compensation device for a test capacitor, characterized in that, include: An insulating platform (3) is provided, with an insulating support (4) connected to the bottom of the insulating platform (3). Several capacitors (2) are placed on the insulating platform (3) in a single layer. Each capacitor (2) has a sleeve (1) on its top, and the sleeves (1) are connected to each other by wiring (5). The outer shells of the capacitors (2) are connected to each other by equipotential lines (6). The bottom of the insulating support (4) is connected to an insulating support column base grounding wire (7).

2. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, The insulating support (4) is an insulating support column, and the bottom of the insulating support (4) has a metal base.

3. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, The capacitor (2) is placed vertically on the insulating platform (3), and the length of the insulating support (4) is less than 2m.

4. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, The number of insulating platforms (3) is greater than one. Multiple insulating platforms (3) are arranged in multiple groups. Each group of insulating platforms (3) is arranged linearly. The capacitors (2) in the same group of insulating platforms (3) form a capacitor group. The capacitors (2) in the same capacitor group are connected in parallel.

5. The reactive power compensation device for a test capacitor according to claim 4, characterized in that, The capacitor banks are connected by star or delta connection to form a three-phase output, or multiple banks are connected in parallel or series to form a single-phase output.

6. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, Both the wiring (5) and the equipotential line (6) are bare copper wires.

7. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, The insulating platform (3) is an insulating wooden board.

8. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, The capacitor (2) is an oil-filled capacitor.

9. The reactive power compensation device for a test capacitor according to claim 1, characterized in that, The capacitance of the capacitor (2) is 50 kvar, 100 kvar, 200 kvar, 300 kvar, or 500 kvar.

10. A reactive power compensation device for a test capacitor according to claim 1, characterized in that, The insulating support (4) is an insulator.

Images