Reactive power compensation device

Abstract

The utility model relates to a reactive power compensation device, which comprises an incoming cable and a three-phase isolation grounding switch electrically connected with the incoming cable, and the three-phase isolation grounding switch comprises an operating mechanism used for operating the three-phase isolation grounding switch to switch between an isolation position and a grounding position. Wherein the free end of the rotating shaft of the operating mechanism is designed to extend into a bearing positioned in a shell of the reactive power compensation device, so that the free end of the rotating shaft is pivotally supported near the shell of the reactive power compensation device. According to the utility model, the reactive power compensation device is allowed to be arranged in a limited or long and narrow space without influencing daily use or maintenance of the reactive power compensation device by maintainers.

Description

Technical Field

[0001] The utility model relates to the technical field of medium and high voltage reactive power compensation, in particular to a medium and high voltage reactive power compensation device. Background Art

[0002] With the rapid development of the national economy, there are more and more high-voltage and large-capacity power equipment, the power quality of the power system is getting worse and worse, and the power factor is getting lower and lower. With the country's higher and higher requirements for the power quality and power factor of the power system, a high-voltage reactive power compensation device suitable for local compensation, high power, and high voltage level came into being. The so-called reactive power compensation, referred to as reactive compensation, plays a role in improving the power factor of the power grid in the power supply system, reducing the loss of power supply transformers and transmission lines, improving power supply efficiency, and improving the power supply environment. Therefore, the reactive power compensation device plays an indispensable and very important role in the power supply system.

[0003] At present, with the continuous development and maturity of high-voltage AC and DC power transmission, customers have higher requirements for the performance of high-voltage electrical equipment. At present, for reactive power compensation equipment, safer operation, more convenient installation and maintenance, smaller footprint, stronger environmental adaptability and other aspects are becoming the mainstream elements pursued by users. In order to meet user needs and quickly meet delivery dates, reactive power compensation equipment manufacturers need to respond quickly to user needs.

[0004] In order to realize the switching of the reactive power compensation device, the isolating grounding switch is an indispensable component in the reactive power compensation device. The isolating grounding switch is a switch that allows maintenance personnel to operate manually. With the increase of power load, the electrical devices in the reactive power compensation device need to be frequently inspected and maintained, and the isolating grounding switch needs to be frequently opened and closed during operation and maintenance, and the number of operations is relatively large, so the convenience and safety of its operation are required to be high. It is known that the operating mechanism of the existing isolating grounding switch often needs to be arranged in a housing on one side of the rotating shaft of the isolating grounding switch. Due to the structural design of the operating handle, in order to enable maintenance personnel to reduce the operating torque when manually operating the isolating earthing switch, when designing the size and spatial layout of the operating mechanism of the isolating earthing switch, it is necessary to consider the operating space and safe live distance required for each operating part, and it is also necessary to consider the convenience of on-site operation and maintenance personnel for maintenance. This often makes the position where the operating mechanism can be placed in the reactive compensation device quite limited, or may cause the size of the reactive compensation device to be undesirably large, thereby failing to make more reasonable and effective use of the precious factory site and causing a certain amount of site waste, and also unfavorably increasing the land cost.

[0005] Therefore, there is a technical demand in the relevant technical field to improve the existing reactive power compensation device to allow a more flexible arrangement of the operating mechanism of the isolating grounding switch, thereby easily achieving miniaturization of the reactive power compensation device and compactness of the structural design. Utility Model Content

[0006] Therefore, the task of the present invention is to provide a reactive power compensation device to overcome the above-mentioned shortcomings of the prior art.

[0007] According to one aspect of the utility model, a reactive power compensation device is provided, which is used to be electrically connected to a three-phase power distribution system including phase A, phase B and phase C for reactive power compensation, wherein the reactive power compensation device comprises: an incoming cable electrically connected to the three-phase power distribution system including phase A, phase B and phase C and a three-phase isolating and grounding switch electrically connected to the incoming cable, wherein the three-phase isolating and grounding switch comprises: a mounting seat; three groups of insulators respectively used for phase A, phase B and phase C; a contact seat fixedly mounted to the mounting seat by means of insulators; an isolating knife switch pivotally mounted to the mounting seat to be electrically connected to the contact seat in an isolated position; and a grounding knife switch pivotally mounted to the mounting seat to be electrically connected to the contact seat in a grounded position; a three-phase reactor connected in series to the downstream of the three-phase isolating and grounding switch via a busbar, wherein the three-phase reactor is configured to be grounded; a three-phase reactor connected in series to the three-phase reactor and used for A plurality of capacitor groups for phases A, B and C, wherein these capacitor groups are constructed to be at least partially supported in an insulating platform; and an operating mechanism for operating a three-phase isolating and earthing switch to switch between an isolating position and a earthing position, wherein the operating mechanism comprises: a first shaft pivoted on a mounting seat and operatively connected to the isolating knife switch; a second shaft pivoted on a mounting seat and operatively connected to the earthing knife switch, wherein the second shaft is operatively connected to the first shaft via a linkage rod; wherein the free end of at least one of the first shaft and the second shaft is designed to extend into a bearing located in a housing of a reactive compensation device so that its free end is pivotally supported near the housing of the reactive compensation device; an operating handle pivoted to the housing, wherein the operating handle is operatively connected to the free end of at least one of the first shaft and the second shaft to allow the three-phase isolating and earthing switch to be manually placed in the isolating position or the earthing position.

[0008] According to the reactive power compensation device of the utility model, by increasing the span of the first axis or the second axis in the operating mechanism, the joint point between the operating handle and the operating crank arm and the first axis or the second axis is transferred to the vicinity of the housing of the reactive power compensation device, so that the operating handle can be adjusted in the axial direction and in the radial direction orthogonal to the axial direction, thereby making the arrangement position of the operating handle and the knife switch in the isolating grounding switch more flexible. This helps to arrange the reactive power compensation device in a limited or narrow space (avoiding waste of space and reducing floor space) without affecting the daily use or maintenance of the reactive power compensation device by maintenance personnel.

[0009] In some embodiments, the first shaft extends into a bearing within a housing of the reactive power compensation device, wherein a length of the first shaft is substantially at least 1.5 times a length of the second shaft.

[0010] In some embodiments, the invention further includes a plurality of discharge coils connected in series downstream of the plurality of capacitor banks, wherein the plurality of discharge coils are connected in series with each other.

[0011] In some embodiments, it also includes an operating crank arm pivotally disposed between the operating handle and the free end of the first shaft, wherein the operating crank arm is arranged adjacent to the housing of the reactive power compensation device.

[0012] In some embodiments, the first shaft and the second shaft both have a protruding rocker portion, wherein the linkage rod is pivotally connected to the rocker portions of the first shaft and the second shaft to form a planar four-bar linkage mechanism for interlocking the isolation switch and the grounding switch.

[0013] In some embodiments, the mounting base of the three-phase isolating grounding switch is spaced apart from the housing of the reactive compensation device by a first distance along the axial direction of the first axis, and the operating handle is arranged to be spaced apart from the first axis by a second distance along the radial direction of the first axis, wherein the first distance is substantially three times the second distance.

[0014] In some embodiments, the operating handle is arranged below the three-phase isolating and earthing switch, wherein the operating crank arm is pivoted obliquely upward from the operating handle to the free end of the first shaft so that the operating crank arm and the mounting base of the three-phase isolating and earthing switch form an acute angle of no more than 45 degrees.

[0015] In some embodiments, the bearing is built into the housing of the reactive power compensation device via an insulating member.

[0016] In some embodiments, the bearing and the operating handle are located on the same side relative to the mounting seat.

[0017] Some of the other features and advantages of the present invention will be apparent to those skilled in the art after reading this application, and the other parts will be described in the following specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0019] Figure 1 is a top view of the reactive power compensation device according to the utility model;

[0020] Figure 2 It is a front view of the operating mechanism in the reactive power compensation device according to the utility model;

[0021] Figure 3 It is a side view of the operating mechanism in the reactive power compensation device according to the utility model, wherein the operating mechanism is located at a grounded position;

[0022] Figure 4 It is a side view of the operating mechanism in the reactive power compensation device according to the utility model, wherein the operating mechanism is located in an isolated position.

[0023] Description of reference numerals:

[0024] 1000, reactive power compensation device; 100, three-phase isolating grounding switch; 200, busbar;

[0025] 300, frame; 400, three-phase reactor; 500, capacitor bank; 600, discharge coil;

[0026] 700, insulator; 10, operating handle; 20, operating crank arm; 20A, swing arm;

[0027] 30. bearing; 40. first shaft; 41. second shaft; 42. linkage rod;

[0028] 50, mounting seat; 50A, 50B, 50C, insulators; 51-54, contact seats;

[0029] 51A, 52A, 53A, 54A, grounding switch;

[0030] 51B, 52B, 53B, 54B; isolation switch;

[0031] 51C, isolating contact; 51D, grounding contact; K, span; DETAILED DESCRIPTION

[0032] Now, with reference to the accompanying drawings, a schematic scheme of the reactive power compensation device disclosed in the utility model is described in detail. Although the accompanying drawings are provided to present some embodiments of the utility model, the accompanying drawings do not have to be drawn according to the dimensions of the specific implementation scheme, and certain features may be enlarged, removed or partially cut to better illustrate and explain the disclosure of the utility model. Some components in the accompanying drawings can be adjusted in position according to actual needs without affecting the technical effect. The phrase "in the accompanying drawings" or similar terms appearing in the specification do not necessarily refer to all drawings or examples.

[0033] Certain directional terms used to describe the drawings below, such as "inside", "outside", "above", "below" and other directional terms, will be understood to have their normal meanings and refer to those directions involved when the drawings are normally viewed. Unless otherwise specified, the directional terms described in this specification are basically in accordance with the conventional directions understood by those skilled in the art.

[0034] The terms "first", "first", "second", "second" and the like used in the present invention do not indicate any order, quantity or importance, but are used to distinguish one component from other components.

[0035] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the present invention is described in detail below with reference to the embodiments.

[0036] exist Figure 1 The reactive power compensation device 1000 according to the present invention is shown in FIG. 1 , which is used to be electrically connected to a three-phase power distribution system including phases A, B and C of, for example, 10 to 33 kV to perform reactive power compensation (see FIG. 1 ). Figure 1 ,), in the embodiment shown here, the reactive power compensation device 1000 can adopt a frame-type design, wherein the reactive power compensation device 1000 includes the following multiple different types of electrical components in sequence to meet the technical requirements of reactive power compensation of the reactive power compensation device. Since the reactive power compensation device 1000 will also be used in a restricted factory building or outdoor complex environment, this puts higher requirements on the flexible layout, floor space and ease of operation of the reactive power compensation device. It is expected that the reactive power compensation device can be flexibly arranged in a restricted or narrow space without affecting the daily use or maintenance of the reactive power compensation device 1000 by maintenance personnel.

[0037] To this end, in this embodiment, the reactive power compensation device 1000 can be designed as a generally long shell, in which the shell can be made of one of aluminum-zinc coated plates, composite plates or non-metals, and it is also feasible to have a sufficiently far safety live distance from the electrical components in the reactive power compensation device 1000. The overall size of the shell is, for example, a rectangle with a width of 2.2 meters and a length of 5 meters, wherein a plurality of electrical components to be described in detail below are arranged in sequence along the long side direction of the shell, and when the reactive power compensation device is arranged against a wall, a plurality of inspection doors for maintenance personnel to enter the reactive power compensation device 1000 are provided at the long side opposite to the wall. Of course, those skilled in the art can adaptively adjust the overall size of the reactive power compensation device 1000 based on the teachings of the utility model, which does not depart from the scope of the utility model, as long as the reactive power compensation device 1000 can meet a sufficient protection level (for example, outdoor IP55 level) and ensure the safe use of the reactive power compensation device 1000.

[0038] Next, we will combine Figure 1 Each electrical component in the reactive power compensation device 1000 is described in more detail.

[0039] like Figure 1 As shown, the reactive power compensation device 1000 is provided with an incoming line cabinet for being electrically connected to a three-phase power distribution system including phase A, phase B and phase C of 10 to 33 kV, and an incoming line cable electrically connected to the three-phase power distribution system including phase A, phase B and phase C is provided at the side wall of the incoming line cabinet, and the incoming line cable includes three contacts respectively connected to the three phases A, phase B and phase C of the power distribution system. Further, a three-phase isolating grounding switch 100 electrically connected to the incoming line cable is installed on the side wall of the incoming line cabinet by means of an insulator to serve as a clear disconnection point in the entire electrical system to control the power on or off of the reactive power compensation device 1000 in the isolated position, and the three-phase isolating grounding switch 100 can also allow the electrical circuit to be grounded in the grounding position to ensure the safety of the maintenance personnel when moving the electrical components into or out of the reactive power compensation device 1000. In order to facilitate the operator to know whether the reactive compensation device 1000 is currently energized, a energized display is preferably connected to the cabinet wall of the incoming line cabinet, which lights up when the reactive compensation device 1000 is energized to improve the operational safety of the reactive compensation device 1000.

[0040] As in Figure 2As shown in detail in FIG. 1 , the three-phase isolating earthing switch 100 according to the utility model includes, for example, a rectangular mounting seat 50 that can be mounted to the side wall of the incoming line cabinet, wherein a plurality of groups of insulators for phase A, phase B, phase C and phase N are arranged side by side at a sufficiently large safe live distance in the width direction of the rectangular mounting seat 50. In the utility model, the three-phase isolating earthing switch 100 is preferably designed to include, in addition to the incoming lines for phase A, phase B and phase C, an N phase with a neutral point and a grounding knife switch that can be connected to the reactor 400, so that when the knife switch of N is engaged, the reactor 400 and the capacitor group 500 connected thereto can be fully and quickly discharged to zero potential, thereby better ensuring the safety of the maintenance personnel. Of course, those skilled in the art know that although the isolating earthing switch 100 is preferably designed to be additionally provided with 4 poles of the N phase with a neutral point for the reactor, this is not necessary, that is, the isolating earthing switch 100 without the N phase or the neutral point also belongs to the part intended to be protected by the utility model patent.

[0041] As an example, in Figure 3-4 , a set of insulators 50A, 50B, 50C for one of the items is shown, wherein the insulator 50B is used to fix the contact base 51 to the mounting base 50, wherein the contact base 51 has a grounding contact 51D located above and an isolating contact 51C located below. Figure 3-4 As shown, a grounding switch 51A is pivotally mounted above the rectangular mounting seat 50, wherein the grounding switch 51A is as shown in FIG. Figure 3 As shown, the three-phase isolating and grounding switch 100 can be pivoted to be electrically connected with the grounding contact 51D on the contact seat 51, so that the three-phase isolating and grounding switch 100 is in its grounding position. At the same time, an isolating knife switch 51B is pivotally mounted below the rectangular mounting seat 50 by means of an insulator 50A, wherein the isolating knife switch 51B is as shown in FIG. Figure 4 As shown, the three-phase isolating and grounding switch 100 can be pivoted to be electrically connected to the isolating contact 51C on the contact seat 51, so that the three-phase isolating and grounding switch 100 is in its isolating position. Figure 1 As shown, the three-phase isolating and grounding switch 100 is operably connected to an operating handle 10 which is pivotally attached to the housing of the reactive compensation device 1000 as part of an operating mechanism (to be described in detail below), thereby allowing maintenance personnel to safely operate the three-phase isolating and grounding switch 1000 to switch between an isolation position and a grounding position.

[0042] Next, a three-phase reactor 400 is arranged in a grounding manner on one side of the reactive power compensation device 1000 away from the three-phase isolating grounding switch 1000, wherein the three-phase isolating grounding switch 1000 is electrically connected to the three-phase reactor 400 located downstream thereof by means of a busbar 200 suspended by a plurality of insulators 700. Here, the three-phase reactor 400 will also be electrically connected to the capacitor bank 500 located downstream thereof to suppress the amplification of high-order harmonics of the power grid system and limit the capacitor closing inrush current. Specifically, here, the three-phase reactor 400 is used to suppress the 5th, 7th and above harmonics with a reactance rate of 5% to 6%, and is used to suppress the 3rd and above harmonics with a reactance rate of 12 to 13%. Reactors with different reactance rates are configured according to the harmonics of the user's on-site system to limit the closing inrush current and suppress the harmonic current of the system. As a preferred aspect, a current transformer connected in series between the three-phase isolating grounding switch 1000 and the three-phase reactor 400 may be further provided, wherein the current transformer may be configured to monitor the current flowing through the three-phase reactor 400 to disconnect the circuit under preset conditions.

[0043] A plurality of capacitor banks 500 connected to the three-phase reactor 400 and used for phase A, phase B and phase C are arranged between the three-phase isolation grounding switch 1000 and the three-phase reactor 400. Specifically, the phase A capacitor bank, the phase B capacitor bank and the phase C capacitor bank each include a plurality of capacitors connected in series with each other, and each of these capacitor banks is connected to the corresponding phases of phase A, phase B and phase C. In this article, these capacitor banks 500 are used to provide capacitive reactive power to compensate for the inductive reactive power in the system, so as to improve the power factor of the power grid, improve the quality of the distribution voltage, reduce losses, and increase the supply capacity of the power equipment, so as to obtain safe, reliable and economical operation of the distribution system. Here, these capacitor banks 500 can be arranged on an insulating platform composed of a steel frame and a support insulator 700 as an example.

[0044] As a preferred aspect, in the present invention, each capacitor in the capacitor bank 500 is respectively wound with a film-paper composite insulation structure composed of polypropylene film and cable paper, wherein the number of layers of the polypropylene film and cable paper is more than 20 layers and the outermost layer is cable paper. Based on such a design, the part of the capacitor in the capacitor bank 500 where the capacitance is too small or the part where the field strength is concentrated is reinforced, and the composite insulation structure is used to solve the problem of the small main insulation of the capacitor, so that the safe charged distance of the capacitor bank can be significantly reduced.

[0045] As a preferred aspect, a plurality of discharge coils 600 may be sequentially arranged downstream of the capacitor bank 500 , wherein the discharge coils 600 may be configured to allow the capacitor bank 500 in the reactive power compensation device 1000 to perform a discharge operation under predetermined conditions.

[0046] During normal use of the reactive power compensation device 1000, in order to prevent the grounding wire from being switched on and the grounding wire from being energized, it is desirable that the three-phase isolating grounding switch 1000 be designed to be located in its isolating position and grounding position alternatively, which can be achieved by means of Figure 2-4 This is achieved by the operating mechanism shown in detail in FIG.

[0047] Specifically, Figure 2 As shown, the operating mechanism of the present invention comprises a first shaft 40 pivotally mounted on a mounting seat 50 and operatively connected to isolation knife gates 51B, 52B, 53B, wherein preferably Figure 3-4 As shown in the figure, the first shaft 40 has a plurality of tie rod insulators 50C arranged side by side at a sufficiently large safety live distance along its own axial direction, wherein these tie rod insulators 50C are respectively connected to the middle parts of the isolating switches 51B, 52B, 53B, and 54B, thereby the isolating switches 51B, 52B, 53B, and 54B can be pivoted by means of the rotation of the first shaft 40 itself and then through the tie rod insulators 50C, thereby placing the three-phase isolating and grounding switch 1000 in the isolating position or pivoting away from the isolating position.

[0048] like Figure 2 As shown, above the first shaft 40, a second shaft 41 is pivotally provided on the mounting seat 50, which is parallel to the first shaft 40 and spaced a sufficient distance away, wherein the second shaft 41 is operationally connected to multiple grounding switches 51A, 52A, 53A, and 54A at a sufficiently large safety energized distance along its own axial direction, thereby enabling the grounding switches 51A, 52A, 53A, and 54A to pivot by means of the rotation of the second shaft 41 itself, thereby placing the three-phase isolating grounding switch 1000 in the grounding position or pivoting away from the grounding position.

[0049] As a preferred aspect, in order to achieve interlocking between the first shaft 40 and the second shaft 41, for example, to prevent the switch from closing with a grounding wire and hanging the grounding wire with power on, the first shaft 40 and the second shaft 41 in the operating mechanism both have a protruding swing rod portion (such as Figure 3 and 4 As shown), and these rocker parts are all pivotally connected to the linkage rod 42 constructed as a straight rod, so that the first shaft 40, the second shaft 41 and the linkage rod 42 pivotally connected thereto form a planar four-bar linkage with four pivot points relative to the mounting seat 50, that is, the pivoting movement of the first shaft 40 itself must drive the second shaft 41 to rotate accordingly with the help of the linkage rod 42, and then drive the isolation switch or the grounding switch to open or close respectively to achieve the grounding or disconnection of the internal circuit of the reactive compensation device. This transmission achieved by relying on a mechanical structure has high reliability, and the implementation method is simple and safe, thereby effectively solving the problem of avoiding accidental electric shock caused by improper operation during the maintenance of the reactive compensation device 1000.

[0050] In order to flexibly arrange the reactive power compensation device 1000 in a limited or narrow space and reduce the torque required by the maintenance personnel when operating the operating mechanism, the operating mechanism in the present invention has a span K greater than that of the conventional operating mechanism. Here, the increased span K is achieved by extending the free end of the first shaft 40. Figure 2 It is shown that the free end of the first shaft 40 is extended, but those skilled in the art know that it is also feasible to extend the free end of the second shaft 41 or to extend both free ends.

[0051] like Figure 2 As shown, unlike conventional operating mechanisms, the first shaft 40 in the operating mechanism of the utility model has an increased span K so that its free end extends to the vicinity of the housing of the reactive compensation device 1000, and here it is extended into a bearing 30 built into the housing of the reactive compensation device via an insulating member. Here, the bearing 30 is preferably a thrust bearing to avoid undesired axial movement of the first shaft 40. Thus, the free end of the first shaft 40 is allowed to be pivotally supported near the housing of the reactive compensation device. Here, the length of the increased span K in the axial direction can be designed to be roughly half of the length of the second shaft 41, that is, at this time, the axial length of the first shaft 40 is, for example, roughly at least 1.5 times the length of the second shaft 41.

[0052] Correspondingly, an operating handle 10 is arranged adjacent to the first shaft 40 in a radial direction orthogonal to the axial direction of the first shaft 40, wherein Figure 1 As shown, the operating handle is arranged to be spaced apart from the first axis 40 by a second distance L2 along the radial direction of the first axis 40. Correspondingly, the mounting base 50 of the three-phase isolating and grounding switch 100 is spaced apart from the housing of the reactive power compensation device 1000 by a first distance L1 along the axial direction of the first axis 40. Here, the first distance L1 is substantially three times the second distance L2. Such a layout allows the reactive power compensation device 1000 to maintain a narrow and long shape design to reduce the footprint.

[0053] In order to perform operation transmission between the first shaft 40 and the operating handle 10 which are arranged close to each other in the radial direction of the first shaft 40, as shown in FIG. Figure 2 As shown, an operating crank arm 20 is pivotally provided between the operating handle 10 and the first shaft 40 in a manner close to the housing of the reactive power compensation device 1000 or the bearing 30 or the free end of the first shaft 40, so that the bearing 30 and the operating handle 10 are located on the same side relative to the mounting seat 50. Figure 2 The left side of the figure is shown in the figure. Figure 3-4As better shown in FIG. 1 , since the mounting base 50 is often located above the operating handle 10 and the first axis 40 has an increased span K from the reactive power compensation device 1000, it is possible to fully utilize the space volume in the reactive power compensation device 1000. Specifically, it can be as follows Figure 3-4 As shown, the slender rod-shaped operating crank arm 20 is pivoted upward from the operating handle 10 to the free end of the first shaft 40, so that the operating crank arm 20 and the mounting seat 50 of the three-phase isolating grounding switch 100 generally form an acute angle of no more than 45 degrees, preferably an acute angle of approximately 30 degrees. Such a design, on the one hand, ensures that the action of the operating crank arm 20 will not cause undesirable interference with any electrical components in the reactive power compensation device 1000, and on the other hand, such a transmission switch allows maintenance personnel to operate the first shaft 40 in a labor-saving manner. Preferably, a swing arm 20A can also be additionally provided between the operating handle 10 and the operating crank arm 20, wherein the swing arm 20A is designed to pivot about 90 degrees around its own pivot axis, and by virtue of its size design, the torque required for maintenance personnel to pull the operating handle 10 can be further reduced.

[0054] Next, combine Figure 3 and Figure 4 To describe the working mode of the operating mechanism of the utility model.

[0055] like Figure 4 As shown, the three-phase isolating grounding switch 100 is in its isolating position at this time. If the maintenance personnel need to perform power-off grounding maintenance on the reactive power compensation device 1000, they can manually pull the operating handle 10 downward in the clockwise direction. The operating handle 10 then pulls down the operating crank arm 20 with the help of the swing arm 20A, thereby driving the first shaft 40 to rotate clockwise around its own axis. Since the first shaft 40 is pivotally supported by the bearing 30 and the operating crank arm 20 is operatively connected to the free end of the first shaft 40, this reduces the torque of the maintenance personnel to actuate the first shaft 40. The clockwise pivoting of the first shaft 4O itself drives the pull rod insulator 50C arranged in sequence along its axial length and the isolating switches 51B, 52B, 53B, and 54B connected thereto to rotate in the clockwise direction, which causes the isolating switches 51B, 52B, 53B, and 54B to be disconnected from the conductive connection with the isolating contacts 51C on the corresponding contact seats 51 to 54, i.e., pivot away from their isolating positions.

[0056] At the same time, the rotation of the first shaft 40 causes the linkage rod 42 pivotally connected to the protrusion on the first shaft 40 to move vertically downward accordingly, which in turn drives the second shaft 40 to move clockwise around its own axis with the help of the protrusion on the second shaft 41. The second shaft 41 pivots in the clockwise direction and drives the grounding switches 51A, 52A, 53A, and 54A arranged in sequence along its axial length to rotate in the clockwise direction, thereby achieving conductive connection with the grounding contacts 51D on the corresponding contact seats 51, i.e., pivoting to their grounding positions. Thus, the three-phase isolating grounding switch 100 can be switched from the isolation position to its grounding position with the help of the operating handle 10.

[0057] Similarly, if the three-phase isolating grounding switch 100 needs to be switched from the grounding position back to the isolating position, the maintenance personnel only need to operate the handle 10 to move upwards, and the operating arm 20 will drive the first shaft 40 and the second shaft 41 to move counterclockwise around their own axes. As a result, the grounding switches 51A, 52A, 53A, and 54A rotate counterclockwise to pivot away from the grounding contact 51D on the contact seat 51, while the isolating switches 51B, 52B, 53B, and 54B rotate counterclockwise to pivotally engage the isolating contact 51C on the contact seat 51, thereby switching the three-phase isolating grounding switch 100 from the grounding position back to its isolating position.

[0058] Those skilled in the art can understand that, with the aid of such an operating mechanism, two independent operating processes of isolation and grounding can be realized at one time, and there will be no mistakes of mistakenly hanging the ground wire with power on and mistakenly closing the switch with the ground wire. At the same time, since the junction point between the operating handle 10 and the operating crank arm 20 and the first shaft 40 or the second shaft 41 is located near the housing of the reactive power compensation device 1000, the operating handle 10 no longer needs to be arranged adjacent to the mounting seat 50, but can be adjusted in the axial direction and in the radial direction orthogonal to the axial direction, so that the arrangement position of the operating handle and the knife switch in the isolation and grounding switch is more flexible. This helps to arrange the reactive power compensation device into a limited or narrow space (avoiding waste of space and reducing floor space) without affecting the daily use or maintenance of the reactive power compensation device 1000 by maintenance personnel.

[0059] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0060] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A reactive power compensation device, which is used to be electrically connected to a three-phase power distribution system including phase A, phase B and phase C for reactive power compensation, characterized in that: The reactive power compensation device comprises: An incoming cable electrically connected to a three-phase power distribution system of phases A, B and C, and a three-phase isolating and grounding switch electrically connected to the incoming cable, wherein the three-phase isolating and grounding switch comprises: Mounting seat; Three sets of insulators for phase A, phase B and phase C respectively; A contact holder fixedly mounted to a mounting seat by means of an insulator; An isolating knife switch pivotably mounted to the mounting base to be in electrical conduction with the contact base in the isolating position; and A grounding switch pivotably mounted to the mounting base to be electrically connected to the contact base in a grounding position; A three-phase reactor connected in series via a busbar to a downstream of a three-phase isolating and earthing switch, wherein the three-phase reactor is configured to be grounded; a plurality of capacitor banks connected in series to the three-phase reactor, respectively for phase A, phase B, and phase C, wherein the capacitor banks are configured to be at least partially supported within the insulating platform; and An operating mechanism for operating a three-phase isolating and earthing switch to switch between an isolating position and an earthing position, wherein the operating mechanism comprises: A first shaft pivotally mounted on a mounting seat and operatively connected to the isolating knife switch; A second shaft pivotally mounted on the mounting seat and operatively connected to the earthing switch, wherein the second shaft is operatively connected to the first shaft via a linkage rod; wherein the free end of at least one of the first shaft and the second shaft is designed to extend into a bearing located in a housing of the reactive power compensation device so that the free end is pivotally supported near the housing of the reactive power compensation device; An operating handle is pivotally connected to the housing, wherein the operating handle is operatively connected to a free end of at least one of the first shaft and the second shaft to allow the three-phase isolating and earthing switch to be manually placed in an isolating position or an earthing position.

2. The reactive power compensation device according to claim 1, characterized in that: The first shaft is extended into a bearing in a housing of the reactive power compensation device, wherein the length of the first shaft is generally at least 1.5 times the length of the second shaft.

3. The reactive power compensation device according to claim 1, characterized in that: Also included are a plurality of discharge coils connected in series downstream of the plurality of capacitor banks, wherein the plurality of discharge coils are connected in series with each other.

4. The reactive power compensation device according to claim 2, characterized in that: It also includes an operating crank arm pivotally arranged between the operating handle and the free end of the first shaft, wherein the operating crank arm is arranged adjacent to the housing of the reactive power compensation device.

5. The reactive power compensation device according to claim 4, characterized in that: The first shaft and the second shaft both have a protruding rocker portion, wherein the linkage rod is pivotally connected to the rocker portions of the first shaft and the second shaft to form a planar four-bar linkage mechanism for interlocking the isolation switch and the grounding switch.

6. The reactive power compensation device according to claim 4, characterized in that: The mounting base of the three-phase isolating earthing switch is spaced apart from the housing of the reactive compensation device by a first distance along the axial direction of the first axis, and the operating handle is arranged to be spaced apart from the first axis by a second distance along the radial direction of the first axis, wherein the first distance is substantially three times the second distance.

7. The reactive power compensation device according to claim 6, characterized in that: The operating handle is arranged below the three-phase isolating and earthing switch, wherein the operating crank arm is pivoted obliquely upward from the operating handle to the free end of the first shaft so that the operating crank arm and the mounting base of the three-phase isolating and earthing switch form an acute angle of no more than 45 degrees.

8. The reactive power compensation device according to claim 1, characterized in that: The bearing is built into the housing of the reactive power compensation device via an insulating member.

9. The reactive power compensation device according to claim 1, characterized in that: The bearing and the operating handle are located on the same side relative to the mounting seat.

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