A miniaturized on-load voltage regulating switch and on-load voltage regulating method

Abstract

The present invention discloses a miniaturized on-load voltage regulating switch and an on-load voltage regulating method, which are characterized in that the three-phase on-load voltage regulating switch is used for frequent voltage adjustment of a distribution transformer under load, and comprises a base plate, a driving mechanism, a selection switch assembly, a switching switch assembly, and a transition assembly. The switch adopts a linear design, and adopts electromagnets and permanent magnets to switch and select the drive, eliminating the spring energy storage mechanism with a complex mechanical structure, so that the switch structure is simple and small in size, improves the operational reliability, reduces the production cost, and is installed in the distribution transformer without changing the conventional volume and shape of the distribution transformer, thereby reducing the production cost of producing on-load voltage regulating distribution transformers. At the same time, the switch adopts a vacuum arc extinguishing chamber for switching during the voltage regulation process, which avoids the influence of arcing caused by contact switching on the performance of the transformer insulating oil, reduces the maintenance cost brought to the user by oil filtering and oil changing, and realizes maintenance-free during the life cycle of the switch, which is suitable for a large number of distribution transformers.

Description

Technical Field

[0001] The present invention relates to the field of on-load voltage regulation of distribution transformers, and in particular to a miniaturized on-load voltage regulation switch and an on-load voltage regulation method. Background Art

[0002] With the continuous development of social economy and the continuous improvement of people's living standards, higher and higher requirements are put forward for the quality of electric energy. Voltage is one of the main indicators to measure the quality of electric energy. The voltage stability of the entire transmission and distribution network is achieved by on-load voltage regulation of transformers at all levels, but the on-load voltage regulation of distribution transformers has not been promoted. Since the existing on-load voltage regulator will generate arcs when switching under power, long-term and frequent arcs affect the performance of insulating oil and require regular maintenance. The existing on-load voltage regulators that use vacuum arc extinguishing have complex mechanical structures, large volumes, and high costs, and are not suitable for a large number of distribution transformers.

[0003] Beijing Pingkai Intelligent Electric Co., Ltd. has applied for the following invention patent in China: Application No.: 201610121960, Invention Name: A Permanent Magnet Vacuum On-load Voltage Regulating Switch, Transformer and On-load Voltage Regulating Method. The core of its protection is to use a permanent magnet mechanism and two vacuum interrupter chambers per phase to simplify its structure, but its patent does not explain the components of its switch and their necessary connection features. From the attached drawings 4 and 5 of its specification and the introduction of related principles, it can be seen that its components are not fixed on the same board, and the structural design is relatively complex, which increases the length, width and height of the switch, and the volume is still large. Compared with the on-load voltage regulating switch in the prior art, although the structural complexity of the motor drive is avoided, the technical effect achieved by it still cannot meet the demand for on-load voltage regulation of a large number of distribution transformers. When installed in a conventional 100kVA distribution transformer, the volume of the distribution transformer needs to be increased to install the switch, which will increase the cost of users to produce on-load voltage regulating distribution transformers. Secondly, when the on-load voltage regulating method in its specification is used for voltage regulation transition, there is a problem of large voltage fluctuation. Because its transition circuit is fixed in the same position, rather than following the change of the voltage regulating gear, it will cause large voltage fluctuations during voltage adjustment transition, affecting the voltage quality. At the same time, its manual explains the voltage regulation method of using the voltage regulating winding to set proportionally, and explains its advantages: it can save the number of taps compared to the demand for a large number of gears; but for a small number of gears, such as 3 to 7 gears (5 gears are more commonly used in the market), the voltage regulating taps of this voltage regulation method will increase and it will also increase the workload and insulation cost when winding the transformer winding. Summary of the invention

[0004] The present invention provides a miniaturized on-load voltage regulating switch and an on-load voltage regulating method, so that the transformer can adjust the voltage uninterruptedly under load. The vacuum arc extinguishing is adopted to solve the maintenance problem. Meanwhile, the structure is simple and the volume is small. The conventional shape and volume of the transformer can be installed in the distribution transformer without changing the transformer (the conventional shape and volume can be installed in the distribution transformer with a capacity of 100kVA without changing the transformer). The reliability is improved and the production cost of the on-load voltage regulating transformer is reduced. The invention is suitable for a large number of distribution transformers.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0006] A miniaturized on-load voltage regulating switch, characterized in that it is a three-phase on-load voltage regulating switch used for frequent voltage adjustment of a distribution transformer under load, comprising a base plate, a drive mechanism, a selection switch assembly, a switching switch assembly, and a transition assembly, and all components of the switch are mounted on the same surface of the base plate;

[0007] The driving mechanism includes a permanent magnet, an electromagnet, a linear guide rail A, a linear guide rail B, and a metal support frame;

[0008] The selector switch assembly comprises a moving contact, a stationary contact, a moving contact insulating frame, and a stationary contact insulating frame;

[0009] The switching switch assembly includes a vacuum interrupter, a static contact insulating seat, and a moving contact insulating seat;

[0010] The transition assembly includes a transition element and a transition insulating seat;

[0011] The electromagnet drives the linear guide rail B to move, and the linear guide rail B drives the moving contact insulation seat to move, and then drives the moving contact of the vacuum interrupter to move, connect or disconnect the corresponding vacuum interrupter, and complete the switching of the voltage regulating main circuit and the transition circuit;

[0012] The permanent magnet drives the linear guide rail A to move, and the linear guide rail A drives the moving contact insulation frame to move, thereby driving the moving contact in the selection switch assembly to select the static contact, thereby completing the selection of the corresponding voltage regulation gear.

[0013] According to a preferred embodiment of the present invention, the permanent magnet and the electromagnet are both fixed to the base plate via the metal support frame, the driving rod of the permanent magnet is fixedly connected to the linear guide rail A, and the driving rod of the electromagnet is fixedly connected to the linear guide rail B.

[0014] According to a preferred embodiment of the present invention, the moving contact in the selection switch assembly is fixed to the linear guide rail A through the moving contact insulating frame, the stationary contact is fixed to the base plate through the stationary contact insulating frame, and the stationary contacts are located on both sides of the moving contact.

[0015] According to a preferred embodiment of the present invention, each phase includes two vacuum arc chambers, the moving contacts of the two vacuum arc chambers of each phase are fixed on the same moving contact insulating seat, the moving contact insulating seat is fixed on the linear guide rail B, and the static contact of each vacuum arc chamber is fixed on the base plate through the static contact insulating seat.

[0016] According to a preferred embodiment of the present invention, one of the two vacuum interrupters in each phase is connected to the voltage regulating main circuit, and the other is connected to the voltage regulating transition circuit. The two vacuum interrupters in each phase are connected or disconnected in a timely manner under the drive of the electromagnet.

[0017] According to a preferred embodiment of the present invention, the vacuum interrupter chambers of the three phases are arranged in a straight line.

[0018] According to a preferred embodiment of the present invention, the transition element is fixed on the base plate via the transition insulating seat.

[0019] According to a preferred embodiment of the present invention, bearings are provided below the linear guide rails A and B, and the bearings are fixed on the base plate.

[0020] According to a preferred embodiment of the present invention, the number and connection mode of the moving contacts and the static contacts in the selection switch assembly are determined according to the number of voltage regulation gears and the connection mode of the voltage regulation circuit.

[0021] An on-load voltage regulation method, characterized in that it is used for the transformer to continuously regulate the voltage under load, including a main circuit and a transition circuit, and the on-load voltage regulation switch is used to switch the voltage regulation gear;

[0022] When voltage adjustment is performed, the miniaturized vacuum on-load voltage regulating switch connects the vacuum interrupter connected to the transition circuit, and the transition circuit is turned on; then the vacuum interrupter connected to the main circuit is disconnected, and the corresponding selection switch is selected in the absence of current and connected to the corresponding voltage regulating tap;

[0023] After the gear selection is completed, the vacuum interrupter in the main circuit is connected first, and the vacuum interrupter in the transition circuit is disconnected, and the voltage regulation is completed.

[0024] Compared with the prior art, the beneficial effect of the present invention is that the electromagnet and permanent magnet are used to adjust the voltage regulating gear, which not only simplifies the voltage regulating process, but also has a simple structure and small size (installed in the distribution transformer without changing the volume and shape of the conventional distribution transformer), greatly simplifies the structure of the on-load voltage regulating switch, improves the operating reliability, and reduces the production cost of the user's on-load distribution transformer. At the same time, it uses a vacuum interrupter for switching during the voltage regulation process, avoiding the impact of arcing due to contact switching on the performance of the transformer insulating oil, and reducing the maintenance cost brought to the user due to oil filtering and oil changing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a miniaturized on-load voltage regulating switch of the present invention.

[0026] Figure 2 It is a schematic diagram of the principle of an on-load voltage regulation method of the present invention. DETAILED DESCRIPTION

[0027] 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. They are selected embodiments of the present invention, not all embodiments, and cannot be used to limit the scope of protection of the present invention. All other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1 , is a miniaturized on-load voltage regulating switch of the present invention, comprising a base plate 1, a driving mechanism 2, a selection switch assembly 3, a switching switch assembly 4, and a transition assembly 5. The driving mechanism 2, the selection switch assembly 3, the switching switch assembly 4, and the transition assembly 5 are all installed on the same surface of the base plate 1.

[0029] The driving mechanism 2 includes a permanent magnet 6, an electromagnet 7, a linear guide A8, a linear guide B9, and a metal support frame 10; the permanent magnet 6 and the electromagnet 7 are fixed to the base plate 1 through the metal support frame 10, the driving rod of the permanent magnet 6 is fixedly connected to the linear guide A8, and the driving rod of the electromagnet 7 is fixedly connected to the linear guide B9; bearings are provided under the linear guides A8 and B9, and the bearings are fixed on the base plate 1 for supporting and reducing the friction of the linear guides A8 and B9 during operation.

[0030] The selection switch assembly 3 includes a moving contact 11, a stationary contact 12, a moving contact insulating frame 13, and a stationary contact insulating frame 14; the moving contact 11 is fixed to the linear guide rail A8 through the moving contact insulating frame 13, and the stationary contact 12 is fixed to the base plate 1 through the stationary contact insulating frame 14, and the stationary contacts 12 of each phase are located on both sides of the moving contact 11.

[0031] The switching switch assembly 4 includes a vacuum arc chamber 15, a static contact insulating seat 16, and a moving contact insulating seat 17; each phase includes two vacuum arc chambers, and the vacuum arc chambers of the three phases are arranged in a straight line. The moving contacts of the two vacuum arc chambers of each phase are fixed on the same moving contact insulating seat 17, and the moving contact insulating seat 17 is fixed on the linear guide B9. The static contact of each vacuum arc chamber is fixed on the base plate 1 through the static contact insulating seat 16.

[0032] The transition assembly 5 includes a transition element 18 and a transition insulating seat 19 , and the transition element 18 is fixed on the base plate 1 via the transition insulating seat 19 .

[0033] When voltage regulation is required, the driving rod of the electromagnet 7 drives the linear guide B9 to move linearly, and the linear guide B9 drives the moving contact insulating seat 17 to move, thereby driving the moving contact of the vacuum interrupter 15 to control the connection or disconnection of the corresponding vacuum interrupter 15.

[0034] The driving rod of the permanent magnet 6 drives the linear guide rail A8 to move linearly, and the linear guide rail A8 drives the moving contact insulation frame 13 to move, and then drives the moving contact 11 to move, so as to select the static contact 12.

[0035] See also Figure 2 Taking the voltage regulation gear position as 5 gears and the voltage regulation circuit connection adopting the coarse and fine adjustment method as an example, a method using Figure 1 The principle of the on-load voltage regulation method of the on-load voltage regulating switch; Figure 2 D1 and D2 in each phase represent vacuum interrupter, K1, K2, K3 represent selection switches in the main circuit, K4 and K5 represent selection switches in the transition circuit, K1, K2, K3, K4 and K5 can select upper and lower contacts, R represents transition resistance, L1, L2 and L3 represent transformer voltage regulating winding, L3, L2 and L1 winding turns ratio = 2:1:1, L3 is the coarse adjustment section of the voltage regulating winding, L1 and L2 are fine adjustment sections.

[0036] K1, K2, and K3 are connected in the main circuit, the vacuum interrupter D2 is connected in the main circuit, K4 and K5 are connected in the transition circuit, and the transition resistor R and the vacuum interrupter D1 are connected in the transition circuit. During normal operation, the vacuum interrupter D2 is connected, that is, the main circuit is turned on, and D1 is disconnected, that is, the transition circuit is disconnected. When voltage adjustment is required, the drive mechanism drives K4 and K5 to make a selection (the transition circuit is adjusted according to the gear change). After the selection is completed, the vacuum interrupter D1 is connected and the transition circuit is turned on; then the vacuum interrupter D2 is driven to disconnect, the main circuit is disconnected, and the drive mechanism drives the selection switches K1, K2, and K3 to select and adjust according to the required voltage adjustment instructions; after the selection is completed, the vacuum interrupter D2 is connected, the main circuit is turned on, the vacuum interrupter D1 is disconnected, and the transition circuit is disconnected, completing a voltage adjustment. During the voltage adjustment process, the selection switches K1, K2, K3, K4, and K5 are all selected when there is no current.

[0037] The transition sequence is introduced by taking the transition from the first gear to the second gear of the voltage regulation as an example: when the first gear is operating normally, K1, K2, and K3 are all connected to their respective lower contacts, the vacuum interrupter D2 is in the on state, and D1 is in the off state; when it is necessary to adjust the voltage from the first gear to the second gear, the selection switch K5 in the transition circuit connects its lower contact, the vacuum interrupter D1 is turned on, and the transition circuit is turned on; then the vacuum interrupter D2 is disconnected, the main circuit is disconnected, and the selection switch K3 selects to connect its upper contact, and K1 and K2 are still connected to their lower contacts; after the selection is completed, the vacuum interrupter D2 is turned on, and the main circuit is turned on; then the vacuum interrupter D1 is disconnected, the transition circuit is disconnected, and the voltage regulation from the first gear to the second gear is completed.

[0038] The selector switches K4 and K5 in the transition circuit can also be omitted. Figure 2 The transition circuit connecting the transition resistor R and the vacuum interrupter D2 is directly fixedly connected to the main tapping gear of the voltage regulating winding or other selected voltage regulating gears without the selection switches K4 and K5. When the gear is adjusted, the transition circuit no longer changes with the change of the gear, but is always fixedly connected at the same position; compared with the voltage regulation method in which the transition circuit changes with the gear change, the transition circuit is fixed at a selected tapping gear, and its voltage fluctuates greatly when the voltage is adjusted and transitioned; for areas with high voltage quality requirements, it is advisable to use the voltage regulation method in which the transition circuit changes with the gear change.

[0039] Figure 2The voltage regulation principle is introduced by taking a coarse and fine adjustment voltage regulation circuit connection method with 5 voltage regulation gears as an example. There are also various voltage regulation circuits such as linear adjustment, positive and negative adjustment, which can all use the on-load voltage regulating switch of the present invention to adjust the voltage. Different numbers of voltage regulation gears (the recommended number of gears is 5 to 17, and the number of gears is determined according to user needs) and different voltage regulation circuit connection methods require different numbers of selection switches and connection combinations, but they can all be achieved using the above-mentioned on-load voltage regulation structure and on-load voltage regulation method.

[0040] In summary, the switch adopts a linear design scheme as a whole, and the driving mechanism linearly drives the movement of the selection switch component and the switching switch component, which greatly simplifies the mechanical structure of the switch and improves the reliability of the switch; at the same time, all components of the switch are installed on one side of the same base plate, and the spatial position of each component is reasonably compact through linear arrangement and combination, which greatly reduces the size of the switch, so that the switch can be installed in the distribution transformer without changing the conventional size and shape of the distribution transformer (the distribution transformer with a capacity of 100kVA does not need to change the conventional shape and volume), reducing the production cost of the switch and the production cost of the user's on-load voltage regulation distribution transformer. At the same time, the switch uses a vacuum interrupter to switch the gear, avoiding the impact of the arcing caused by contact switching on the performance of the transformer insulating oil, reducing the maintenance cost brought to the user by oil filtering and oil changing, and realizing maintenance-free during the life cycle of the switch, which is suitable for a large number of distribution transformers.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, 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: A three-phase on-load voltage regulating switch used for frequent voltage adjustment of a distribution transformer under load, comprising a base plate, a driving mechanism, a selection switch assembly, a switching switch assembly, and a transition assembly, wherein all components of the switch are mounted on the same surface of the base plate; the switch as a whole adopts a linear design structure, and the driving mechanism linearly drives the movement of the selection switch assembly and the switching switch assembly; The driving mechanism includes a permanent magnet, an electromagnet, a linear guide rail A, a linear guide rail B, and a metal support frame; The selector switch assembly comprises a moving contact, a stationary contact, a moving contact insulating frame, and a stationary contact insulating frame; The switching switch assembly comprises a vacuum interrupter, a static contact insulating seat, and a moving contact insulating seat, and the three-phase vacuum interrupters are arranged in a straight line; The transition assembly includes a transition element and a transition insulating seat; Bearings are provided below the linear guide rail A and the linear guide rail B, and the bearings are fixed to the bottom plate; the permanent magnet and the electromagnet are fixed to the bottom plate through the metal support frame, the driving rod of the permanent magnet is fixedly connected to the linear guide rail A, and the driving rod of the electromagnet is fixedly connected to the linear guide rail B; The moving contact in the selection switch assembly is fixed on the linear guide rail A through the moving contact insulation frame, and the stationary contact is fixed on the bottom plate through the stationary contact insulation frame, and the stationary contacts are located on both sides of the moving contact; The number and connection mode of the moving contacts and the static contacts in the selection switch assembly are determined according to the number of voltage regulation gears and the connection mode of the voltage regulation circuit; The electromagnet drives the linear guide rail B to move, and the linear guide rail B drives the moving contact insulation seat to move, and then drives the moving contact of the vacuum interrupter to move, connect or disconnect the corresponding vacuum interrupter, and complete the switching of the voltage regulating main circuit and the transition circuit; The permanent magnet drives the linear guide rail A to move, and the linear guide rail A drives the moving contact insulation frame to move, thereby driving the moving contact in the selection switch assembly to select the static contact, thereby completing the selection of the corresponding voltage regulation gear.

2. A miniaturized on-load voltage regulating switch according to claim 1, characterized in that: Each phase includes two vacuum interrupter chambers, and the moving contacts of the two vacuum interrupter chambers of each phase are fixed on the same moving contact insulating seat, and the moving contact insulating seat is fixed on the linear guide rail B. The stationary contact of each vacuum interrupter chamber is fixed on the base plate through the stationary contact insulating seat.

3. A miniaturized on-load voltage regulating switch according to claim 1, characterized in that: One of the two vacuum interrupters in each phase is connected to the voltage regulating main circuit, and the other is connected to the voltage regulating transition circuit. The two vacuum interrupters in each phase are connected or disconnected in a timely manner under the drive of the electromagnet.

4. A miniaturized on-load voltage regulating switch according to claim 1, characterized in that: The transition element is fixed on the base plate through the transition insulating seat.

5. A method for on-load voltage regulation, characterized in that: Used for uninterrupted voltage adjustment of the transformer under load, including a main circuit and a transition circuit, and using a miniaturized on-load voltage-regulating switch described in any one of claims 1 to 4 to switch the voltage adjustment gear; when adjusting the voltage, the miniaturized on-load voltage-regulating switch connects the vacuum arc extinguishing chamber connected to the transition circuit, and the transition circuit is turned on; then the vacuum arc extinguishing chamber connected to the main circuit is disconnected, and its corresponding selection switch component is selected in the absence of current and connected to the corresponding voltage regulating tap; after the gear selection is completed, the vacuum arc extinguishing chamber in the main circuit is connected first, and the vacuum arc extinguishing chamber in the transition circuit is disconnected, and the voltage adjustment is completed.

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