Spare transformer wide adaptation system and method based on impedance element

Abstract

The invention discloses a spare part transformer wide adaptation system and method based on an impedance element, relates to the technical field of transformers, and solves the problems that in the prior art, a power grid 220kV transformer has many voltage combinations and impedance combinations, spare parts with fixed parameters are poor in adaptability, part of spare part transformers are prone to being idle for a long time, and power consumption is low. Or the fault transformer lacks an appropriate spare transformer. According to the invention, the change of the basic voltage of each winding of the transformer is realized by adopting a variable magnetic flux technology, and the combination matching problem of different voltages of each winding can be realized by combining the tapping taps in a proper voltage regulating range. A conventional impedance transformer is adopted to reserve an expansion interface and can be externally connected with a modular reactance element, and switching of different high-impedance values, low-impedance values and medium-low-impedance values is achieved according to application scenes. The development of flexible and wide-adaptability spare part transformers is realized, and the utilization efficiency of the spare part transformers is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a spare transformer wide adaptation system and method based on impedance elements. Background Art

[0002] As an indispensable primary equipment in the power system, power transformers have the characteristics of high value, multiple models, and long fault recovery cycle. Proper reserve of spare transformers is of great significance to shorten the power outage time and improve the power supply reliability index. After a transformer fails, a spare transformer is usually put into use to ensure the stable operation of the power grid.

[0003] The common practice is to use 3 (or 6) single-phase transformers to form 1 (or 2) transformer groups for ultra-high voltage transformers with large transformer capacity, and configure a single spare transformer of the same model to improve power supply reliability. For 220kV power transformers, most provincial grid companies purchase a certain number of spare transformers based on statistical analysis of parameters such as model and impedance. However, the existing 220kV transformers in the power grid have many voltage combinations and impedance combinations, and the spare parts with fixed parameters have poor adaptability. It is easy for some spare transformers to be idle for a long time, or there is a lack of suitable spare transformers for faulty transformers. The social and economic benefits are poor, and it is difficult to ensure the stable operation of the power grid.

[0004] In view of this, a spare transformer wide adaptation system and method based on impedance elements is needed. Summary of the invention

[0005] In view of the fact that the 220kV transformer of the power grid in the prior art has many voltage combinations and impedance combinations, and the spare parts with fixed parameters have poor adaptability, it is easy for some spare transformers to be idle for a long time, or there is a lack of suitable spare transformers for faulty transformers. The present invention provides a wide adaptation system and method for spare transformers based on impedance elements, which can achieve matching of different high impedance values ​​by externally connecting reactor groups with different reactance values. When the application scenario is 14% / 24% / 8% conventional impedance, the transformer body can be put into operation; when the application scenario is 14% / 35% / 20% high impedance, reactor module 1 is connected in series on the low-voltage side of the transformer; when the application scenario is 14% / 50% / 35% high impedance, reactor module 2 is connected in series on the low-voltage side of the transformer. Through the combination of high voltage (on-load voltage regulation), medium voltage (no-load voltage regulation) low voltage, and voltage stabilizing coils, a spare transformer that adapts to 2 connection groups, 3 impedances, and multiple voltage level transformers is realized. The specific technical scheme is as follows:

[0006] A spare transformer wide adaptation system based on impedance elements, comprising:

[0007] The transformer unit includes a voltage regulating coil, a high-voltage coil, a medium-voltage coil, a low-voltage coil, a voltage stabilizing coil, a high-voltage on-load voltage regulator and an iron core, wherein the voltage stabilizing coil, the low-voltage coil, the medium-voltage coil, the high-voltage coil and the voltage regulating coil are arranged in sequence from the iron core outward;

[0008] An impedance element unit, comprising a reactor, wherein the impedance element unit is arranged at one side of the transformer unit and is used to be connected to the transformer unit;

[0009] The extended interface unit is arranged in the transformer unit and the impedance element unit, and is used to open an interface in the transformer unit and the impedance element unit and connect them through the interface.

[0010] Preferably, the extended interface unit arranged on the transformer unit includes six interfaces led out from the three-phase ends of the low-voltage coil.

[0011] Preferably, the expansion interface unit provided on the transformer unit further includes:

[0012] Three ports led out from the three-phase head end of the voltage stabilizing coil and a common interface led out from the tail end;

[0013] Three ports led out from the three-phase head end of the medium voltage coil and a common interface led out from the tail end;

[0014] Three ports led out from the three-phase head end of the high-voltage coil and a common interface led out from the tail end.

[0015] Preferably, the expansion interface unit provided in the reactance element unit includes six interfaces led out from the reactor.

[0016] Preferably, the reactor is oil-immersed and has an independent oil tank.

[0017] Preferably, the independent oil tank is suspended at the end of the transformer body and at one end close to the low voltage side.

[0018] Preferably, the independent low-voltage lead is led out from the upper and lower ends of the oil tank through three low-voltage bushings respectively, and is connected to the three corresponding bushings on the upper and lower walls of the reactor group box.

[0019] A wide adaptation method for spare transformers based on impedance elements is applied to the system as described above, and is specifically as follows:

[0020] Based on the expansion interface unit on the transformer unit, the impedance element unit is externally connected to realize the change of high-low and medium-low impedance. The transformer unit adopts a conventional impedance transformer, and the conventional impedance is: 14% / 24% / 8%;

[0021] When the application scenario is 14% / 35% / 20% high impedance, the reactor module 1 is connected in series on the low-voltage side of the transformer unit. The reactor module 1 is a module in the reactance element unit.

[0022] When the application scenario is 14% / 50% / 35% high impedance, the reactor module 1 and the reactor 2 are connected in series on the low-voltage side of the transformer unit, and the reactor module 2 is a module in the reactance element unit.

[0023] Preferably, the reactor module 1 adopts CKSG-825000 / 11.

[0024] Preferably, the reactor module 2 adopts CKSG-825000 / 38.5.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention adopts variable flux technology to achieve the change of the basic voltage of each transformer winding. Combined with the tapping of the appropriate voltage regulation range, the combination matching problem of different voltages of each winding can be achieved. The conventional impedance transformer is used to reserve an expansion interface, and the modular inductor element can be connected externally. According to the application scenario, the switching of high-low, medium-low and different high impedance values ​​can be achieved. The development of flexible and widely adaptable spare transformers is realized, and the utilization efficiency of spare transformers is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0028] Figure 1 It is a schematic diagram of the transformer unit structure of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the expansion interface unit of the present invention;

[0030] Figure 3 This is the low voltage wiring diagram;

[0031] Figure 4 Wiring diagram for YNyn0d11;

[0032] Figure 5 This is the wiring diagram for YNyn0yn0+d11.

[0033] Description of reference numerals:

[0034] 1- voltage regulating coil, 2- high voltage coil, 3- medium voltage coil, 4- low voltage coil, 5- voltage stabilizing coil, 6- high voltage on-load voltage regulation. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0037] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0038] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] Combine the following Figure 1-Figure 5 , the implementation modes of the present invention are further described.

[0040] In one embodiment of the present invention, a spare transformer wide adaptation system based on impedance elements is provided, comprising:

[0041] Transformer units, such as Figure 1 As shown, it includes a voltage regulating coil, a high-voltage coil, a medium-voltage coil, a low-voltage coil, a voltage stabilizing coil, a high-voltage on-load voltage regulator and an iron core, wherein the voltage stabilizing coil, the low-voltage coil, the medium-voltage coil, the high-voltage coil and the voltage regulating coil are arranged in sequence from the iron core to the outside;

[0042] The impedance element unit includes a reactor, which is arranged on one side of the transformer unit and is used to connect to the transformer unit. The reactor is oil-immersed and has an independent oil tank, which is suspended at the end of the transformer body and at one end close to the low-voltage side. The independent low-voltage lead is led out from the upper and lower ends of the oil tank through three low-voltage bushings, and connected to the three bushings corresponding to the upper and lower walls of the reactor group box.

[0043] The extended interface unit is arranged in the transformer unit and the impedance element unit, and is used to open an interface in the transformer unit and the impedance element unit and connect them through the interface.

[0044] The expansion interface unit provided on the transformer unit includes:

[0045] Six interfaces are led out from the three-phase ends of the low-voltage coil.

[0046] Three ports led out from the three-phase head end of the voltage stabilizing coil and a common interface led out from the tail end;

[0047] Three ports led out from the three-phase head end of the medium voltage coil and a common interface led out from the tail end;

[0048] Three ports led out from the three-phase head end of the high-voltage coil and a common interface led out from the tail end.

[0049] The expansion interface unit provided in the reactance element unit includes six interfaces led out from the reactor.

[0050] This embodiment is aimed at the problem that the voltage and voltage regulation range of transformers in operation in different regions of the power grid are different. The measures of designing wide-range voltage regulation power transformers are adopted to achieve the matching of different voltage levels to meet the requirements of parallel operation. The high voltage is designed into a wide range of on-load voltage regulation, and the medium voltage is combined with the no-load voltage regulation line segment to achieve the switching of different voltages. The impedance of transformers in operation in the power grid is divided into conventional impedance (14% / 24% / 8%) and high impedance (14% / 35% / 20%, 14% / 50% / 35%). The conventional impedance transformer is used to reserve an expansion interface, and the modular inductive element can be connected externally. According to the application scenario, the switching of high, low, medium and low high impedance values ​​can be achieved.

[0051] The use of conventional impedance transformers combined with three-phase reactor groups (impedance elements) is a feasible technology for realizing high-impedance transformers. The current mainstream 220kV high-impedance transformers have two types of high-low and medium-low impedance values, namely 14% / 50% / 35% and 14% / 35% / 20%. As mentioned above, based on the 14% / 24% / 8% transformer, it is considered to achieve the change of high-low and medium-low impedance by connecting the reactor in series on the low-voltage side. After market research, the technology that can adjust the reactance value at will is not mature at present, and it is possible to consider externally connecting reactor groups with different reactance values ​​to achieve the matching of different high impedance values. The reactor group can have an independent oil tank, and the base and bracket are designed and installed on the transformer body. When the reactor group is used, the required reactor group is directly hung on the wall of the oil tank, and the upper and lower soft connection bellows are used to connect to the transformer body oil tank to meet the heat dissipation needs of the reactor during operation.

[0052] like Figure 2 As shown in the figure, the low voltage winding has 6 bushings from the three-phase head and tail, which are represented by a, b, c, y, z, and x respectively; for the voltage stabilizing winding, 4 bushings are led out, which are the three-phase head ends Sa, Sb, and Sc respectively, and the tail ends share a common outlet represented by So; the medium voltage leads out 4 bushings, which are the three-phase head ends Am, Bm, and Cm respectively, and the tail ends share a common outlet represented by Om (medium voltage zero phase); the high voltage leads out 4 bushings, which are the three-phase head ends A, B, and C respectively, and the tail ends share a common outlet represented by O (high voltage zero phase); the reactor leads out 6 outlets, which are Indicated by a', b', c', y', z', x'. The reactor is oil-immersed and has an independent oil tank. It is suspended at the end of the transformer body, close to the low-voltage side. The low-voltage lead is led out from the upper and lower ends of the oil tank through three low-voltage bushings, and connected to the three bushings corresponding to the upper and lower walls of the reactor group. It is divided into two modules according to different reactance values. When the reactor module 1 is needed, the reactor module 1 is connected to the transformer body. When the reactor module 2 is needed, the reactor module 1 is connected to the transformer body. It can be disassembled when not in use.

[0053] Based on the fixed impedance transformer, the impedance of HL and ML can be increased by connecting a reactor in series on the low-voltage side of the transformer. The series inductor can effectively limit the current during operation and improve the operation quality of the power grid. The principle of the reactor to limit the short-circuit current is as follows: the reactor is connected in series in the circuit, and the principle that the inductive current cannot change suddenly is used to prevent sudden surge current, which can play a role in limiting the short-circuit current. Because the reactor is essentially an inductor coil, when the voltage is turned on, a reverse electromotive force will be formed inside, which hinders the change of the current inside the coil. Therefore, the current of the reactor (inductor) cannot change suddenly, so it can play a role in limiting the short-circuit current.

[0054] Through the different connections of the outer head and tail of the casing, it can be achieved:

[0055] (1) It is composed of high, medium and low voltage coils, with capacity (HV / MV / LV): 150 / 150 / 75MVA, connection group number: YNyn0d11, rated voltage (HV / MV / LV): 230(220) / 121(115) / 11(10.5)kV (the voltage of each voltage level can be combined arbitrarily), such as 220 / 121 / 11kV, 230 / 115 / 10.5kV, etc., impedance voltage (Uk12% / Uk13% / Uk23%).

[0056] (2) By connecting different reactor modules in series, reactor module 1 (CKSG-825000 / 11) and reactor module 2 (CKSG-825000 / 38.5) can achieve three impedances: 14% / 24% / 8%, 14% / 35% / 21%, and 14% / 50% / 35%.

[0057] (3) It is composed of high, medium, low and voltage-stabilizing coils, with a capacity (HV / MV / LV+SV): 150 / 150 / 75+50MVA, connection group number: YNyn0yn0+d11, rated voltage (HV / MV / LV): 230(220) / 121(115) / 38.5(36.67)+11(10.5)kV (except for voltage stabilization, the high, medium and low voltages can be combined arbitrarily), for example 220 / 121 / 38.5+10.5kV, 230 / 115 / 38.5+11kV, etc. Impedance voltage (Uk12%): 14%.

[0058] The variable flux and variable capacity technology is used to achieve the change of the basic voltage of each winding of the transformer, and the combination matching problem of different voltages of each winding is realized by combining the tapping of the appropriate voltage regulation range. The basic voltage of each winding can be switched by the change of magnetic flux, and the switching of different voltages can be achieved by selecting the high-voltage on-load voltage regulation and the medium-voltage no-load voltage regulation gear. The operation is simple and reliable. At the same time, the coil winding process of this structure is simple, the coil ampere-turn arrangement is balanced, the short-circuit resistance is strong, the internal electrical insulation is reliable, and the combination of various operating conditions can be achieved by changing the connection method of the external lead.

[0059] In one embodiment of the present invention, a wide adaptation method for spare transformers based on impedance elements is also provided, which is applied to the system as described above, and is specifically as follows:

[0060] Based on the expansion interface unit on the transformer unit, the impedance element unit is externally connected to realize the change of high-low and medium-low impedance. The transformer unit adopts a conventional impedance transformer, and the conventional impedance is: 14% / 24% / 8%;

[0061] When the application scenario is 14% / 35% / 20% high impedance, the reactor module 1 (CKSG-825000 / 11) is connected in series on the low-voltage side of the transformer unit. The reactor module 1 is the module in the reactance element unit.

[0062] When the application scenario is 14% / 50% / 35% high impedance, the reactor module 1 (CKSG-825000 / 11) and the reactor 2 (CKSG-825000 / 38.5) are connected in series on the low-voltage side of the transformer unit. The reactor module 2 is the module in the reactance element unit.

[0063] In summary, the present invention adopts variable flux technology to achieve the change of the basic voltage of each transformer winding, and combined with the tap of the appropriate voltage regulation range, it can achieve the combination matching problem of different voltages of each winding. The conventional impedance transformer is used to reserve an expansion interface, and the modular inductive element can be externally connected to realize the switching of high, low, medium and low impedance values ​​according to the application scenario. The development of flexible and widely adaptable spare transformers is realized, and the utilization efficiency of spare transformers is improved.

[0064] Those of ordinary skill in the art will appreciate that the units of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition of each example has been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0065] In the embodiments provided by the present invention, it should be understood that the division of units is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units can be combined into one unit, one unit can be split into multiple units, or some features can be ignored, etc.

[0066] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0067] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-0nlyMemory), random access memory (RAM, RandomAccessMemory), mobile hard disk, magnetic disk or optical disk, etc., which can store program code.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A spare transformer wide adaptation system based on impedance elements, characterized in that: include: The transformer unit includes a voltage regulating coil, a high-voltage coil, a medium-voltage coil, a low-voltage coil, a voltage stabilizing coil, a high-voltage on-load voltage regulator and an iron core, wherein the voltage stabilizing coil, the low-voltage coil, the medium-voltage coil, the high-voltage coil and the voltage regulating coil are arranged in sequence from the iron core outwards; An impedance element unit, comprising a reactor, wherein the impedance element unit is arranged at one side of the transformer unit and is used to be connected to the transformer unit; The extended interface unit is arranged in the transformer unit and the impedance element unit, and is used to open an interface in the transformer unit and the impedance element unit and connect them through the interface.

2. According to claim 1, a spare transformer wide adaptation system based on impedance elements is characterized in that: The extended interface unit arranged on the transformer unit comprises six interfaces led out from the three-phase ends of the low-voltage coil.

3. The wide adaptation system for spare transformers based on impedance elements according to claim 1, characterized in that: The expansion interface unit provided on the transformer unit further includes: Three ports led out from the three-phase head end of the voltage stabilizing coil and a common interface led out from the tail end; Three ports led out from the three-phase head end of the medium voltage coil and a common interface led out from the tail end; Three ports led out from the three-phase head end of the high-voltage coil and a common interface led out from the tail end.

4. The wide adaptation system for spare transformers based on impedance elements according to claim 2, characterized in that: The expansion interface unit arranged in the reactance element unit includes six interfaces led out from the reactor.

5. The wide adaptation system for spare transformers based on impedance elements according to claim 1, characterized in that: The reactor is oil-immersed and has an independent oil tank.

6. The wide adaptation system for spare transformers based on impedance elements according to claim 5, characterized in that: The independent oil tank is suspended at the end of the transformer body and at one end close to the low-voltage side.

7. The wide adaptation system for spare transformers based on impedance elements according to claim 5, characterized in that: Independent low-voltage leads are led out from the upper and lower ends of the oil tank through three low-voltage bushings, and connected to the three corresponding bushings on the upper and lower walls of the reactor group box.

8. A method for wide adaptation of spare transformers based on impedance elements, characterized in that: The system applied to any one of claims 1 to 7 is as follows: Based on the expansion interface unit on the transformer unit, the impedance element unit is externally connected to realize the change of high-low and medium-low impedance. The transformer unit adopts a conventional impedance transformer, and the conventional impedance is: 14% / 24% / 8%; When the application scenario is 14% / 35% / 20% high impedance, the reactor module 1 is connected in series on the low-voltage side of the transformer unit. The reactor module 1 is a module in the reactance element unit. When the application scenario is 14% / 50% / 35% high impedance, the reactor module 1 and the reactor 2 are connected in series on the low-voltage side of the transformer unit, and the reactor module 2 is a module in the reactance element unit.

9. The method for wide adaptation of spare transformers based on impedance elements according to claim 8, characterized in that: The reactor module 1 adopts CKSG-825000 / 11.

10. The method for wide adaptation of spare transformers based on impedance elements according to claim 8, characterized in that: The reactor module 2 adopts CKSG-825000 / 38.5.

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