A miniaturized on-load voltage regulating switch and on-load voltage regulating distribution transformer

Abstract

The invention discloses a miniaturized on-load voltage regulating switch and an on-load voltage regulating distribution transformer, comprising a driving mechanism, a metal fixing plate, a selection switch assembly, a switching switch assembly, a transition element, an insulating mounting main board, and an insulating mounting bracket. The three-phase selection switch assembly, the switching switch assembly, and the transition element are mounted on the insulating mounting main board in a trisection form. The miniaturized on-load voltage regulating switch and the on-load voltage regulating distribution transformer are suitable for distribution transformers of any structure, especially three-dimensional wound core transformers. When installed in a distribution transformer, the shape and volume of a conventional distribution transformer are hardly changed, and the production cost increased due to the large volume of the switch is greatly reduced. At the same time, frequent voltage adjustment under load is realized, the power supply voltage is stabilized, and the loss is reduced.

Description

Technical Field

[0001] The device relates to the technical field of electric power products, and in particular to a miniaturized on-load voltage regulating switch and an on-load voltage regulating distribution transformer. Background Art

[0002] The distribution transformer is the last transformer of the power supply network. It is used in various fields of national economy and people's livelihood, and is spread all over every corner of urban and rural areas. The number is huge. The current distribution transformers are all off-excitation voltage regulation mode. When regulating the voltage, it is necessary to cut off the power supply first, and then manually adjust the off-excitation voltage regulating switch. After the adjustment is completed, the power supply can be restored. Since the voltage can only be adjusted by power outage, and it cannot be adjusted in time, the distribution transformer in the actual power supply network is equivalent to no voltage regulation measures, resulting in low qualified rate and poor stability of the power supply voltage, abnormal operation of electrical equipment, and increased losses of the distribution transformer itself and electrical equipment. With the continuous improvement and development of social economy and power grid, the requirements for voltage quality will become higher and higher, and therefore the reliability requirements for on-load voltage regulation distribution transformers will become higher and higher. In order to meet the needs of different types of distribution transformers, the requirements for the reliability, miniaturization and number of voltage regulation gears of on-load voltage regulating switches will continue to increase.

[0003] In recent years, there have been cases where the on-load voltage regulator of the main transformer has been applied to the distribution transformer to achieve on-load voltage regulation. However, the on-load voltage regulator of the main transformer is large in size and requires regular maintenance. It cannot meet the reliability requirements of the distribution transformer and is not suitable for a large number of distribution transformers. There are also on-load voltage regulators on the market that use spring energy storage and permanent magnet and electromagnetic drive methods for distribution transformers. Although vacuum arc extinguishing is also used, this type of drive method has a large impact force during the drive transmission, which affects the service life of the on-load voltage regulator related components, making its life cycle unable to meet the design life cycle of the distribution transformer, and is not suitable for use in a large number of distribution transformers. Recently, linear on-load voltage regulators have also appeared. They are relatively small in size, but their use in three-dimensional coiled iron distribution transformers will greatly increase the manufacturing cost of three-dimensional coiled iron distribution transformers. Summary of the invention

[0004] The purpose of the present invention is to provide a miniaturized on-load voltage regulating switch and an on-load voltage regulating distribution transformer, so as to solve the problem of the on-load voltage regulating distribution transformer in the prior art that requires regular maintenance due to on-load voltage regulating switching, realize the long life and maintenance-free characteristics of the on-load voltage regulating switch, and make its life cycle equal to the life of the distribution transformer body. At the same time, the problem of the on-load voltage regulating switch in the prior art being large in size and inconvenient to install is solved, and the on-load voltage regulating switch is miniaturized. It adopts a disc structure and is suitable for distribution transformers of any structural type. It is the most suitable structural mode of the voltage regulating switch for three-dimensional coiled iron core transformers. It is installed in the distribution transformer, and it is almost unnecessary to change the volume and shape of the conventional distribution transformer for installation.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A miniaturized on-load voltage regulating switch, characterized in that it comprises a driving mechanism, a metal fixing plate, a selection switch assembly, a switching switch assembly, a transition element, an insulating mounting main board, and an insulating mounting bracket;

[0007] The driving mechanism includes a motor, a gearbox, a driving shaft wheel, a transmission gear, a grooved wheel mechanism, and a driving turntable;

[0008] The selection switch assembly of each phase includes two moving contacts and a plurality of stationary contacts;

[0009] The switching switch assembly of each phase includes two vacuum interrupters and two sets of driving arms;

[0010] The motor is connected to the gearbox and mounted on the gearbox;

[0011] The gearbox is mounted on the metal fixing plate;

[0012] The driving shaft wheel is connected to the gearbox;

[0013] The driving shaft wheel is meshed with the transmission gear;

[0014] The moving contact is mounted on the driving rotary disc;

[0015] A plurality of the static contacts, the switching switch assembly, and the transition element are all mounted on the insulating mounting main board;

[0016] The insulating mounting main board is connected to the metal fixing plate through the three insulating mounting brackets;

[0017] The driving turntable is located on the lower side of the pressure bearing on the insulating mounting bracket;

[0018] The motor drives the transmission gear to rotate through the gearbox and the driving shaft, the transmission gear drives the grooved wheel mechanism to operate, the grooved wheel mechanism drives the driving turntable to rotate, the driving turntable drives the moving contact and the driving arm to operate in a timely manner, the moving contact selects the corresponding static contact in the static contact assembly, the driving arm drives the vacuum interrupter to operate, and the voltage regulating gear is switched.

[0019] According to a preferred embodiment of the present invention, the groove wheel mechanism includes a shift rod and a groove wheel, the shift rod is fixedly connected to the transmission gear, a gear is provided on one side of the groove wheel and is integrated with the groove wheel, the transmission gear drives the shift rod thereon to rotate, the shift rod drives the groove wheel to rotate, the rotation of the groove wheel drives the gear to rotate, and the gear meshes with the teeth on the driving turntable to drive the driving turntable to rotate.

[0020] According to a preferred embodiment of the present invention, a cam is arranged on the driving turntable, and the cam drives the driving arm to move, thereby driving the vacuum interrupter to be opened.

[0021] According to a preferred embodiment of the present invention, a through square hole is provided in the middle of the protruding portion of the insulating mounting bracket, a pressure bearing is provided in the square hole, the driving turntable is located below the pressure bearing, and the pressure bearing exerts a certain pressure on the driving turntable.

[0022] According to a preferred embodiment of the present invention, the driving arm includes an arm A, an arm B, and a connecting shaft, the arm A is located on the upper side of the insulating mounting main board, one end of the arm A is connected to the connecting shaft, and the other end is in contact with the driving turntable; the connecting shaft is installed through the insulating mounting main board; the arm B is located on the lower side of the insulating mounting main board, one end of the arm B is connected to the connecting shaft, and the other end is connected to the moving contact of the vacuum arc chamber; the driving turntable drives the arm A to move, the arm A drives the arm B to move through the connecting shaft, and the arm B drives the vacuum arc chamber to move.

[0023] According to a preferred embodiment of the present invention, protrusions are arranged on the insulating mounting main board, and the protrusions are all arranged between the static contacts. The protrusions are all higher than the plane of the static contacts to prevent the moving contact from short-circuiting two adjacent static contacts during movement.

[0024] According to a preferred embodiment of the present invention, the plurality of static contacts are connected to the voltage regulating winding tap of the transformer high-voltage coil, the two vacuum arc extinguishing chambers of each phase are electrically connected to each corresponding moving contact respectively, and the transition element is electrically connected to one vacuum arc extinguishing chamber of each phase.

[0025] According to a preferred implementation manner of the present invention, a connector for communication is provided on the gearbox.

[0026] According to a preferred embodiment of the present invention, the three-phase selection switch assembly, the switching switch assembly, and the transition element are installed on the insulating mounting main board in the form of dividing the insulating mounting main board into three equal parts.

[0027] An on-load voltage-regulating distribution transformer adopts any of the above-mentioned miniaturized on-load voltage-regulating switches.

[0028] Compared with the prior art, the beneficial effect of the present invention is the invention of a miniaturized on-load voltage regulating switch and an on-load voltage regulating distribution transformer. The on-load voltage regulating switch is suitable for distribution transformers of any structure, especially three-dimensional coiled iron core transformers. When installed in a distribution transformer, the shape and volume of the conventional distribution transformer are hardly changed, which greatly reduces the production cost increased by the large volume of the switch; it achieves more than 600,000 trouble-free and maintenance-free continuous voltage regulating actions, and can be maintenance-free within the life cycle of the distribution transformer, thereby improving the reliability of the on-load voltage regulation of the distribution transformer; it achieves frequent voltage adjustment under load, stabilizes the power supply voltage, and reduces losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of a miniaturized on-load voltage regulating switch of the present invention;

[0030] Figure 2 It is a partial mechanism schematic diagram of a miniaturized on-load voltage regulating switch driving mechanism of the present invention;

[0031] Figure 3 This is a structural schematic diagram a of a miniaturized on-load voltage regulating switch of the present invention without part of the driving mechanism;

[0032] Figure 4 This is a structural schematic diagram b of the other side of a miniaturized on-load voltage regulating switch of the present invention without part of the driving mechanism;

[0033] Figure 5 The present invention is a schematic diagram of the voltage regulating gear conversion principle of a miniaturized on-load voltage regulating switch. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings. The embodiments described below are only used to more clearly illustrate the technical solution of the present invention (only a miniaturized on-load voltage regulator with 5 voltage regulating gears is used for illustration), which is the selected embodiment of the present invention, but not all the embodiments, and cannot be used to limit the protection scope of the present invention. All other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present invention.

[0035] Figures 1 to 4 This is a schematic diagram of the structure of a miniaturized on-load voltage regulating switch preferably used in the present invention. Figures 1 to 4A miniaturized on-load voltage regulating switch for a three-phase on-load voltage regulating transformer comprises a driving mechanism, a metal fixing plate 2, a selection switch assembly, a switching switch assembly, a transition element 5, an insulating mounting main board 6, and an insulating mounting bracket 7 (three insulating mounting brackets 7.1, 7.2, and 7.3). The three-phase selection switch assembly, the switching switch assembly, the transition element 5, and the insulating mounting bracket 7 are distributed on the insulating mounting main board 6 in a three-part pattern.

[0036] The driving mechanism comprises a motor 1.1, a gearbox 1.2, a driving shaft wheel 1.3, a transmission gear 1.4, a grooved wheel mechanism 1.5, and a driving turntable 1.6. The gearbox 1.2 is provided with a connector 1.2.1 for transmitting communication information.

[0037] Each phase selection switch assembly includes two moving contacts 3.1, 3.2 and a plurality of stationary contacts, of which five are shown in the figure, namely 3.3.1, 3.3.2, 3.3.3, 3.3.4 and 3.3.5; each phase switching switch assembly includes two vacuum interrupters 4.1, 4.2 and two sets of driving arms 4.3, 4.4.

[0038] The motor 1.1 is connected to the gearbox 1.2, and the motor 1.1 is installed on the gearbox 1.2; the gearbox 1.2 is installed on the metal fixing plate 2; the driving shaft wheel 1.3 is connected to the gearbox 1.2; the driving shaft wheel 1.3 is meshed with the transmission gear 1.4; the groove wheel mechanism 1.5 includes a groove wheel 1.5.1 and a lever, and the lever is fixedly connected to the transmission gear 1.4; the moving contacts 3.1 and 3.2 are installed on the driving turntable 1.6; the static contacts, the switching switch assembly, and the transition element 5 are all installed on the insulating mounting main board 6; the insulating mounting main board 6 is provided with a plurality of protrusions 6.1, and the protrusions 6.1 are all arranged between the static contacts, and the protrusions 6.1 are all higher than the plane of the static contacts to prevent the moving contacts 3.1 and 3.2 from moving relative to each other during the movement. The two adjacent static contacts are short-circuited; the insulating mounting main board 6 is connected to the metal fixing plate 2 through three insulating mounting brackets 7.1, 7.2, and 7.3; a gear is arranged on one side of the groove wheel 1.5.1, and the gear is meshed with the teeth on the driving turntable 1.6, and the rotation of the groove wheel 1.5.1 drives the driving turntable 1.6 to rotate; a plurality of cams 1.6.1 are arranged on the driving turntable 1.6; pressure bearings 7.1.1, 7.2.1, and 7.3 are arranged on the insulating mounting brackets 7.1, 7.2, and 7.3, and the pressure bearings 7.1.1, 7.2.1, and 7.3.1 are pressed on the driving turntable 1.6 to ensure that the moving contacts 3.1, 3.2 on the driving turntable 1.6 and the static contacts on the insulating mounting main board 6 can be electrically connected well.

[0039] The driving arms 4.3 and 4.4 include arm A 4.3.1 and 4.4.1, arm B 4.3.2 and 4.4.2, and connecting shafts 4.3.3 and 4.4.3. The arm A 4.3.1 and 4.4.1 are located on the upper side of the insulating mounting main board, one end of the arm A 4.3.1 and 4.4.1 is connected to the connecting shafts 4.3.3 and 4.4.3, and the other end is in contact with the driving turntable 1.6; the connecting shafts 4.3.3 and 4.4.3 are installed through the insulating mounting main board 6; the arm B 4.3.2 and 4.4.2 are located on the lower side of the insulating mounting main board 6, and the arm B One end of 4.3.2 and 4.4.2 is connected to the connecting shaft 4.3.3 and 4.4.3, and the other end is connected to the moving contact of the vacuum interrupter 4.1 and 4.2; the motor 1.1 drives the transmission gear 1.4 to rotate through the gearbox 1.2 and the driving shaft 1.3, and the transmission gear 1.4 drives the lever thereon to rotate, the lever drives the groove wheel 1.5.1 to rotate, the groove wheel 1.5.1 drives the driving turntable 1.6 to rotate, the driving turntable 1.6 drives the moving contacts 3.1, 3.2 and the driving arms 4.3 and 4.4 to move in a timely manner, the moving contacts 3.1 and 3.2 select one of the corresponding static contacts (the figure shows 5 static contacts 3.3.1, 3.3.2, 3.3.3, 3.3.4 and 3.3.5) to connect, and a plurality of cams 1.6.1 are arranged on the driving turntable 1.6, and the cam 1.6.1 drives the arm A 4.3.1, 4.4.1 are in motion, arm A 4.3.1, 4.4.1 drives arm B 4.3.2, 4.4.2 to move through connecting shaft 4.3.3, 4.4.3, arm B 4.3.2, 4.4.2 drives vacuum interrupter 4.1, 4.2 to move, thus completing the conversion of voltage regulating gear.

[0040] See also Figure 5 The present invention is a miniaturized on-load voltage regulating switch for voltage regulating selection and switching in 7 steps. In the figure, N and N+1 represent two adjacent coil taps of the voltage regulating winding, A and B represent two moving contacts 3.1 and 3.2 in the selection switch assembly, R represents the transition element 5, and D1 and D2 represent two vacuum interrupters 4.1 and 4.2 in the switching switch assembly; the timing of switching from the N+1 tap of the voltage regulating winding to the N tap is:

[0041] Step 1: The moving contacts A and B are connected to the N+1 tap, and the vacuum interrupters D1 and D2 are connected. The current flows from the N+1 tap through the moving contact A and the vacuum interrupter D2;

[0042] Step 2: The vacuum interrupter D2 is disconnected, the moving contact A is disconnected from the N+1 tap, and the moving contact B is still connected to the N+1 tap. The current flows from the N+1 tap through the moving contact B, the vacuum interrupter D1, and the transition element R;

[0043] Step 3: The moving contact B is still connected to the N+1 tap, and the moving contact A is switched from the N+1 tap without current to the N tap. The current flows from the N+1 tap through the moving contact B, the arc extinguishing chamber D1, and the transition element R;

[0044] Step 4: The moving contact B is still connected to the N+1 tap, the vacuum interrupter D2 is closed, the moving contact A is connected to the N tap, the current flows from the N+1 tap through the moving contact B, the vacuum interrupter D1, and the transition element R, and the current flows from the N tap through the moving contact A and the vacuum interrupter D2. At this time, a short-term circulating current is generated between the N+1 tap and the N tap;

[0045] Step 5: The vacuum interrupter D1 is disconnected, the moving contact B is disconnected from the N+1 tap, the moving contact A is still connected to the N tap, and the current flows from the N tap through the moving contact A and the vacuum interrupter D2;

[0046] Step 6: The moving contact A is still connected to the N tap, and the moving contact B is switched from the N+1 tap with no current to the N tap. The current flows from the N tap through the moving contact A and the vacuum interrupter D2.

[0047] Step 7: The moving contact A is still connected to the N tap, the vacuum interrupter D1 is connected, the moving contact B is connected to the N tap, and the current flows from the N tap through the moving contact A and the vacuum interrupter D2;

[0048] The above is an explanation of the voltage selection and switching process of the on-load tap-changing switch. During the entire selection and switching process, the arc is only generated in the vacuum interrupter chamber, and the selection switch components move or select the corresponding contacts in a no-current state, which will not pollute the transformer oil. There is no need to perform regular oil filter maintenance or replace the filter element, which greatly saves the operation and maintenance costs. It is well known to technicians in this technical field and will not be explained again.

[0049] When designing a miniaturized on-load voltage regulating switch, the present invention is developed from the perspectives of miniaturization, maintenance-free, and a life span equivalent to the design life span of a transformer. The driving mechanism of the present invention is driven by a motor 1.1, and a flexible driving strategy is adopted to greatly reduce the impact force on the relevant components (switching switch assembly, selection switch assembly) of the miniaturized on-load voltage regulating switch during the re-driving transmission process, thereby improving the actual service life and reliability of the switch components; a motor protection housing is provided outside the motor 1.1, and the motor protection housing belongs to a fully protected design structure, and a fully protected communication connector is provided on the gearbox, and this design position has a good waterproof and dustproof effect; two vacuum arc extinguishing chambers 4.1 and 4.2 are provided in the switching switch assembly, and when the voltage regulating gear is switched, the two vacuum arc extinguishing chambers 4.1 and 4.2 are only actuated once, compared with other vacuum arc extinguishing chambers that only have one vacuum arc extinguishing chamber, which need to be actuated twice for each gear switching, and need to cooperate with a more complex mechanical mechanism, if the same type of vacuum arc extinguishing chamber is selected, the present invention is twice as long as other vacuum arc extinguishing chambers that only have one vacuum arc extinguishing chamber, thereby improving the reliability of the switch; the maintenance-free service life of the on-load voltage regulating switch can be equivalent to the service life of the transformer body. The present invention adopts an insulating mounting mainboard with sufficient tolerance strength to fix and install various components to reduce the overall height of the on-load voltage regulating switch; at the same time, the selection switch component and the switching switch component of the on-load voltage regulating switch are both arranged on the same insulating mounting mainboard, and the driving transmission mechanism thereof is controlled by the same mechanism in a timing sequence, so that the structural design of the present invention is simple and compact, and the overall design of the switch is miniaturized. By selecting the above-mentioned scheme, the present invention realizes the characteristics of miniaturization, maintenance-free and high reliability of the on-load voltage regulating switch, and is suitable for a large number of distribution transformers. Improvements can be made according to the preferred embodiments of the present invention in the technical field, for example, a motor mechanism such as a servo motor, a linear motor or a stepping motor can be used to replace the motor of the present invention in combination with a control program for driving, which also belongs to the protection scope of the present invention. The preferred embodiment of the present invention is to explain the structure and principle of a miniaturized on-load voltage regulating switch with 5 voltage regulating gears. For other voltage regulating gear numbers (3 gears, 7 gears, 9 gears, 17 gears, etc.), the improved switches made according to the present invention also belong to the protection scope of the present invention.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for technicians in this technical field, several changes and improvements can be made without departing from the technical principles of the present invention. These changes and improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A miniaturized on-load voltage regulating switch, characterized in that: It includes a driving mechanism, a metal fixing plate, a selection switch assembly, a switching switch assembly, a transition element, an insulating mounting main board, and an insulating mounting bracket; The driving mechanism includes a motor, a gearbox, a driving shaft wheel, a transmission gear, a grooved wheel mechanism, and a driving turntable; The selection switch assembly of each phase includes two moving contacts and a plurality of stationary contacts; The switching switch assembly of each phase includes two vacuum interrupters and two sets of driving arms; The motor is connected to the gearbox and mounted on the gearbox; The gearbox is mounted on the metal fixing plate; The driving shaft wheel is connected to the gearbox; The driving shaft wheel is meshed with the transmission gear; The moving contact is mounted on the driving rotary disc; A plurality of the static contacts, the switching switch assembly, and the transition element are all mounted on the insulating mounting main board; The insulating mounting main board is connected to the metal fixing plate through the three insulating mounting brackets; The driving turntable is located on the lower side of the pressure bearing on the insulating mounting bracket; The motor drives the transmission gear to rotate through the gearbox and the driving shaft, the transmission gear drives the grooved wheel mechanism to operate, the grooved wheel mechanism drives the driving turntable to rotate, the driving turntable drives the moving contact and the driving arm to operate in a timely manner, the moving contact selects the corresponding static contact in the static contact assembly, the driving arm drives the vacuum interrupter to operate, and the voltage regulation gear is switched.

2. A miniaturized on-load voltage regulating switch according to claim 1, characterized in that: The groove wheel mechanism includes a shift rod and a groove wheel, the shift rod is fixedly connected to the transmission gear, a gear is provided on one side of the groove wheel and is integrated with the groove wheel, the transmission gear drives the shift rod thereon to rotate, the shift rod drives the groove wheel to rotate, the rotation of the groove wheel drives the gear to rotate, the gear is engaged with the teeth on the driving turntable, and drives the driving turntable to rotate.

3. A miniaturized on-load voltage regulating switch according to claim 1, characterized in that: A cam is arranged on the driving turntable, and the cam drives the driving arm to move, thereby driving the vacuum interrupter to be opened.

4. A miniaturized on-load voltage regulating switch according to claim 1, characterized in that: A through square hole is arranged in the middle of the protruding part of the insulating mounting bracket, the pressure bearing is arranged in the square hole, the driving turntable is located below the pressure bearing, and the pressure bearing exerts a certain pressure on the driving turntable.

5. The miniaturized on-load voltage regulating switch according to claim 1, characterized in that: The driving arm includes an arm A, an arm B, and a connecting shaft, wherein the arm A is located on the upper side of the insulating mounting main board, one end of the arm A is connected to the connecting shaft, and the other end is in contact with the driving turntable; the connecting shaft is installed through the insulating mounting main board; the arm B is located on the lower side of the insulating mounting main board, one end of the arm B is connected to the connecting shaft, and the other end is connected to the moving contact of the vacuum arc chamber; the driving turntable drives the arm A to move, the arm A drives the arm B to move through the connecting shaft, and the arm B drives the vacuum arc chamber to move.

6. The miniaturized on-load voltage regulating switch according to claim 1, characterized in that: Protrusions are arranged on the insulating mounting main board, and the protrusions are all arranged between the static contacts. The protrusions are all higher than the planes of the static contacts, so as to prevent the moving contact from short-circuiting two adjacent static contacts during movement.

7. The miniaturized on-load voltage regulating switch according to claim 1, characterized in that: The plurality of stationary contacts are connected to the voltage regulating winding tap of the transformer high voltage coil, the two vacuum interrupters of each phase are electrically connected to the corresponding moving contacts respectively, and the transition element is electrically connected to one vacuum interrupter of each phase.

8. The miniaturized on-load voltage regulating switch according to claim 1, characterized in that: A connector for communication is arranged on the gearbox.

9. The miniaturized on-load voltage regulating switch according to claim 1, characterized in that: The three-phase selection switch assembly, the switching switch assembly, and the transition element are installed on the insulating mounting main board in the form of dividing the insulating mounting main board into three equal parts.

10. An on-load voltage-changing distribution transformer, characterized in that: An on-load voltage-regulating distribution transformer using the miniaturized on-load voltage-regulating switch according to any one of the preceding claims.

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