Single-phase large-current generating device and large-current transformer test system

Abstract

The utility model discloses a single-phase large-current generating device, a large-current transformer test system and application, a station-used three-phase 380V line is used as a power supply, a rectification filtering loop and an inversion loop are combined, and then the current is boosted to a large current required by a test through N current boosters. The large current is applied to a primary copper conductor of the large current testing device, and after the primary copper conductor penetrates through an inner window hole of a tested piece, the large current or the ultra-large current can be directly applied to the physical center of the plane of the tested piece or the position deviating from the physical center. The method is used for testing and detecting the operation effect and state of related electric power and electrical equipment under direct large current or ultra-large current, and the method is called as a direct method large current test detection method. The defects of inaccuracy, large deviation and the like caused by a simple connection method in which an equal ampere-turn formed by combining a plurality of turns of small currents is adopted to replace a direct large current or an ultra-large current in the prior art are thoroughly overcome.

Description

TECHNICAL FIELD

[0001] The utility model relates to the electrical complete device or equipment field of large current to super large current, specifically relates to a kind of special electrical test device of temperature rise or error test of large current or super large current mutual inductor to the test of power electrical equipment using direct method. BACKGROUND

[0002] At present, the demand and technical level of power equipment at home and abroad are increasingly high, and the power generation capacity of generator set is increasingly large, especially large-scale hydropower, thermal power and even nuclear power unit, and the power generation capacity is above 1000MW, and the highest nuclear power unit currently reaches above 1400MW, which needs to be matched with corresponding large-capacity or super large-capacity power equipment. These matching power electrical equipment, such as super large test generator, super large test transformer, super large current circuit breaker, generator outlet insulating bushing and generator outlet insulating bus, are world problems in production and manufacturing, and it is required to ensure that the current value is above 50000A or even above 55000A for more than 10 minutes, and the long-term stable current-carrying performance is above 45000A or even above 50000A. According to the search, such current value index has not appeared at home and abroad. After the production and manufacturing of these power equipment, large current and super large current test detection and acceptance are required, but there is no corresponding device or equipment to output super large current to directly test the power electrical equipment at home and abroad, that is, the direct large current method is used to test and detect the power equipment with super large current performance, and a small current conductor is wound and combined together to become a turn of conductor directly passing through large (or super large) current, which is also called "equal ampere-turn method". The "equal ampere-turn method" is also called "indirect method" scheme compared with the "direct method" scheme of directly passing large current in a turn of conductor for test and detection, to realize approximate equivalence. The test and detection data will have certain deviation by using the "indirect method" scheme to replace the "direct method" scheme of directly passing large (or super large) current or super large current in a turn of conductor for test and detection, which is not completely equivalent to the test and detection data under actual operation. At the same time, when the number of winding turns is large, the capacity of current output transformer needs to be increased due to the increase of impedance, and larger capacity transformer is needed, which also limits the test. In order to realize more accurate test and detection data, the "direct method" scheme of passing large (or super large) current or super large current in a turn of conductor for test and detection is the best option. SUMMARY

[0003] In view of the deficiencies of the prior art and equipment, the utility model provides a kind of technical scheme of single-phase 50kA super large current generating device and its complete set device or equipment, and this complete set test device can directly test and detect the operating effect and state of relevant power electrical equipment under direct large current or super large current.The structure is simple, the manufacturing cost is low, the performance is reliable, and the current source and the corresponding test detection device capable of outputting stable super large current can be realized in the 380V power system of normal mains or plant power.

[0004] The utility model adopts technical scheme of single-phase large current generating device, including basic power unit and steady current raising unit, the basic power unit includes rectifier circuit and inverter circuit, rectifier circuit is converted into direct current power with three-phase alternating current input power supply, and inverter circuit is converted into alternating current power supply again with direct current power supply, and the alternating current power supply of one phase with relatively large current value is output again through N sets of current riser (abbreviation: riser) parallel current raising in steady current raising unit, wherein, N is greater than or equal to 1, and the large current after current raising is added to the large current busbar of large current test device.

[0005] A kind of large current transformer test detection system using single-phase large current generating device, when N is greater than 1, N sets of current riser are arranged symmetrically with large current busbar as center, the large current test device includes the frame structure of large support, the tested large current transformer is placed in the lower center position of large support, the upper end of large support is provided with upper busbar, the lower end of the tested large current transformer is provided with lower busbar, the riser is electrically connected with the upper busbar and lower busbar through upper side current collection conductor and lower side current collection conductor respectively, lifting motor support frame is connected to the top of large support, lifting motor and gearbox are connected to lifting motor support frame, the gearbox is connected with large current busbar through lead screw, drives the large current busbar to be movable up and down, and is lifted and put down, so that it can pass through the inner cavity of the tested large current transformer and contact with upper busbar and lower busbar.

[0006] Preferably, the large support is made of non-magnetic material, and the non-magnetic material includes hard aluminum alloy profile and non-magnetic stainless steel profile.

[0007] Preferably, the large current busbar is in cylindrical structure and made of T2 copper, and the long-term current-carrying capacity of the large current busbar is more than 55000A.

[0008] Preferably, the large current busbar is internally provided with liquid cooling channels, and external liquid cooling pipes are connected to the busbar to output cooling liquid, and another external liquid cooling pipe is connected to the busbar to discharge the injected cooling liquid, thereby forming flowing liquid cooling.

[0009] A large current transformer test system is applied to the temperature rise and error test of a large current transformer.

[0010] A large current transformer test system is applied to the test and detection of other power equipment related to large current, such as large current circuit breakers, bushings, busbars, etc.

[0011] The beneficial effects of the utility model are: 1. Through the energy conversion superposition principle, a basic starting power supply capable of realizing output single-phase large-capacity super-large current can be easily completed by using conventional plant 380V three-phase power without large-capacity transformers or large-capacity power supplies and other high, large, upper, difficult and other equipment. The conventional three-phase 380V line of the factory power supply system is used as the power supply, and the capacity of each phase is ensured to be more than 150kW (the total capacity of three phases is more than 450kW). If a larger super-large current is to be output, the power supply capacity needs to be increased. Through the technical scheme of combining the rectification filter circuit widely used at present and the corresponding capacity inverter, three-phase alternating current is converted into single-phase direct current, and then the single-phase direct current is converted into single-phase alternating current by the inverter. Through this technical scheme, the total capacity of the three-phase power supply is superimposed together and applied to a single phase. At this time, the output capacity is about three times (about 450kVA) of the original capacity. At this time, if the voltage value is determined to be 400V (which can be adjusted high or low according to the loop required during the super-large current test), the current can reach more than 1000A (estimated according to 150kVA). This provides a necessary power supply capacity and a basic starting current source for subsequent output of super-large current.

[0012] If a larger current is required, the capacity of the plant transformer, the capacity of the rectification filter circuit and the inverter, the capacity of the current booster or the number of current boosters, and the current-carrying capacity of the related conductors of the busbar can be increased accordingly.

[0013] 2. Through the control device and N current booster transformers, the current of the previous basic starting current source is increased to a long-term stable super-large current that can meet the requirements of the power electrical equipment to be tested, so as to realize the requirement of changing a small thing into a big one.

[0014] 3. According to the power electrical equipment to be tested in the super-large current related test, a special test and detection device that can meet the requirements of the super-large current related test is specially designed. For example, a special device for the temperature rise and error test of a super-large current transformer is designed to realize the temperature rise or error test of a super-large current. This kind of special device can be designed and manufactured according to the situation of the equipment to be tested.

[0015] 4. Through the comprehensive test regulation system, different unit parts and units are regulated, and accurate regulation, test detection and coordination between different units of the complete test detection equipment are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 It is a basic circuit principle schematic diagram of the special electrical test device.

[0017] Fig. 2 It is a large current or super large current transformer test system schematic diagram of the utility model.

[0018] Fig. 3 It is a schematic diagram of the N (8) sets of current risers which are uniformly and symmetrically arranged around a single-phase primary super large current conductor.

[0019] Marked in the figure: 1-large support, 2-lower bus bar, 3-lower current collection conductor, 4-support frame of the tested large current transformer, 5-current riser, 6-tested large current transformer, 7-upper current collection conductor, 8-large current collection conductor, 9-upper bus bar, 10-lifting motor support frame, 11-screw rod, 12-speed changer, 13-lifting motor, 14-external cooling liquid pipe. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the embodiments of the utility model described and shown in the drawings herein can be arranged and designed in various different configurations.

[0021] One of the purposes of the utility model is to provide a simple structure, low manufacturing cost, reliable performance, and stable super large current source equipment device which can be output in the normal 380V power system.

[0022] The utility model does not need a special super power power system or power line, nor a special super large current power generation equipment or large current output transformer, but on the conventional factory conventional three-phase 380V line, under the condition of transformer capacity ≥ 150kVA, a relatively simple power source complete equipment device manufacturing scheme method which can stably output super large current (up to 50000A or more) can be developed, and the scheme method includes the following technical units: the schematic diagrams are respectively seen Figs. 1 to 3 .

[0023] I. The basic power supply part of the super large current generating test device: the conventional three-phase 380V line of the factory power supply system is used as the power supply, which ensures that the capacity of its three phases meets 150kVA or more. If you want to output larger super large current, the power supply capacity will be increased. Through the technical scheme of combining the widely used rectifier filter circuit and the corresponding capacity inverter, three-phase alternating current is converted into single-phase direct current, and then the single-phase direct current is converted into single-phase alternating current by the inverter. Through this scheme, the total capacity of the three-phase power supply is stacked together and applied to a single phase. At this time, the output capacity is about three times (about 450kVA) of the original. At this time, if the voltage value is determined to be 400V (which can be adjusted high or low according to the loop required during the super large current test), the current can reach 1000A or more (estimated according to 150kVA). This provides a necessary power supply capacity and a basic current for the subsequent output of super large current. This power supply capacity value is related to the super large current value to be output, and is also related to the impedance value of the entire output large current loop. The wire (conductor) and the total length of the loop (affected by the distance between the test device and the power supply) will affect the required capacity of the power supply of the entire device.

[0024] II. Steady-state super large current raising unit,

[0025] The steady-state current raising unit device uses a single-phase current raising transformer (which can be referred to as a current raiser 5) with a certain capacity to raise the current output by the inverter to the required large current or super large current, as shown in Fig. 1 .

[0026] According to the overall test device, a plurality of larger capacity current risers 5 (the current riser 5 can be selected as a single-phase current riser with large capacity or a plurality of small-capacity single-phase current risers in parallel to form a single-phase current riser with large capacity) correspond to the number of inverters, and the AC current output by the plurality of inverters is raised to a certain high value by the corresponding number of current risers 5, and the current is concentrated and added to the large current bus conductor 8 passing through the inner window of the large current transformer, and the corresponding large current transformer test is performed. The steady-state current raising unit device is first supported by the large bracket 1 as the main support, and the large bracket 1 is a three-dimensional frame structure made of square column hard aluminum alloy profile, non-magnetic stainless steel or other high-strength insulating non-metallic materials. Other auxiliary devices are also made of hard aluminum alloy, non-magnetic stainless steel or other high-strength insulating non-metallic materials (such as epoxy glass, polycarbonate, polytetrafluoroethylene, etc.). The large current bus conductor 8 is arranged at the middle position of the frame, and the large current bus conductor 8 is a cylindrical structure made of T2 copper, which meets the temperature rise requirement when passing through the super-large current for large current transformer related tests. The current is collected by the upper current collection conductor 7 (generally selected as a flexible conductor or a joint rotatable connection type), collected into the upper bus plate 9, and then added to the large current bus conductor 8 (generally copper column) through the upper bus plate 9. The lower bus plate 2 (its plane is in close contact with the end surface of the bus conductor 8, forming a conductive loop), and the lower current collection conductor 3 (generally first using a flexible conductor or a joint rotatable connection type), the large current returns to the current riser 5, thus forming a current loop in the steady-state current raising unit device. The large current bus conductor 8 is internally provided with a liquid cooling channel, and the cooling liquid is output to the bus conductor 8 through the external cooling liquid conduit 14. The cooling liquid injected into the large current bus conductor 8 is guided out through the other external cooling liquid conduit 14, forming a flowing liquid cooling to reduce the temperature of the large current bus conductor 8 itself during the test. This scheme can reduce the cross-section of the large current bus conductor 8, reduce the cost of copper, and reduce the oxidation intensity of the conductor surface, so as to ensure that the surface contact resistance of the conductor is as small as possible.

[0027] At the same time, there is a related electric lifting device on the conductor, and a small supporting lifting motor support frame 10 is further provided on the conductor, a lifting motor 13 for lifting the bus conductor 8 is arranged on the lifting motor support frame 10, a gearbox 12 and a lead screw 11 are used to lift the large current bus conductor 8, the large current bus conductor 8 can be lifted and lowered by a certain distance through the rotating lead screw 11, and the conductor can be moved to pass through the center of the bus type or through type super large current transformer for large current test, to ensure that the tested large current transformer 6 (which has no primary conductor itself) can be sleeved on the super large current conductor, and the super large current conductor is equivalent to the primary conductor of the tested large current transformer 6. After some related test and detection equipment are assembled, associated, regulated and controlled to form a comprehensive control system, a complete set of super large current test and detection system is formed, the large current or super large current transformer is sleeved on the through-flow conductor 8 of the special test and detection device, the conductor 8 serves as the primary winding of the transformer (equivalent to one turn of the primary winding), the comprehensive control system is operated, the current is uniformly increased from a small current to a required current value during test and detection, and related large current or super large current test and detection can be performed. During the test or operation, water or oil and other cooling liquids are injected into and output from the bus conductor 8 through the external cooling liquid pipe 14, and the flowing liquid is used to reduce the temperature of the large current bus conductor 8 itself when a large current flows through the conductor. The through-flow capacity of the conductor of the test device is more than 50,000 A or even more than 55,000 A, which can be guaranteed for more than 10 minutes, and the long-term stable through-flow capacity is more than 45,000 A or even more than 50,000 A.

[0028] If a larger current is required, the capacity of the plant transformer, the capacity of the rectifier filter circuit and the inverter, the capacity or number of the current riser, and the through-flow capacity of the bus conductor can be increased accordingly.

[0029] The special test device is designed by taking the test of temperature rise and error of the super large current transformer as an example, and the steady state single-phase large current of 50000A or above is guaranteed, the current output from the inverter can be increased to a certain large current or super large current by using a large capacity current booster 5, which is equivalent to a large capacity constant current source, and the current booster 5 is used for power supply of the transformer test detection device. Another way can also be used, that is, the current is divided into multiple parts, and each part is connected with a certain capacity current booster 5, so that the current is increased by multiple current boosters 5 and then collected on the same conductor with super large current flow capacity, and the related power electrical equipment is input with large current or super large current. However, for the super large current system, if a large capacity current booster 5 is used, the anti-interference partition can be used to prevent the bias magnetic field and the large leakage reactance of the output current equipment itself, so it is suggested to use multiple current boosters 5. When multiple current boosters 5 are used, the current output from the inverter can be divided into multiple parts through a parallel conductor structure, and each part is connected with a certain large capacity current booster 5, so that the current is increased by multiple current boosters 5 and then collected on the same conductor with super large current flow capacity, and the related power electrical equipment is input with large current or super large current. (If the capacity of the current booster 5 is insufficient, multiple existing small capacity current boosters can also be combined together, which is equivalent to a large current booster 5), when multiple current boosters 5 are used in parallel, the current booster 5 in the special test device is preferably uniformly and symmetrically arranged relative to the input current conductor, which can reduce the influence of the bias magnetic field on the tested equipment and reduce the leakage reactance, and improve the output large current effect.

[0030] Third, the scheme is to take the temperature rise and error test of the super large current transformer as an example to describe the special test detection device.

[0031] Before the invention of this complete set of test equipment (including the power supply part), all domestic and foreign production, research and development, testing and application units used the indirect method when conducting temperature rise tests and error (including composite error) tests on large current, especially ultra-large current transformers. Because the indirect method test is not carried out under the actual operating state of the simulated transformer in the actual working conditions, there may be a certain amount of deviation, which is not completely equivalent to the test and detection data under the actual operating conditions (not the true value). At the same time, when the number of winding turns is large, the capacity of the current output transformer needs to be increased due to the increase in impedance, and a larger capacity transformer is required, which will also impose certain restrictions on the test. Therefore, it is necessary to use the direct method to conduct temperature rise test and error (including composite error) test of through-type large current or ultra-large current. For this purpose, a special test device for temperature rise and error of such ultra-large current transformer is designed and manufactured. It can simulate the actual operating conditions of the transformer. After the test, the real data under the maximum limit and the most severe conditions can be obtained, so as to provide more accurate digital basis or reference for various related links such as research and design, production and manufacturing, quality control, procurement acceptance, installation and operation.

[0032] This design adopts the configuration of 8 current-boosting transformers in parallel (see Fig. 3 These eight current-boosting transformers are arranged symmetrically and evenly in eight directions, centered around the high-current bus conductor 8 of the ultra-high current transformer test device, to maximize current transmission efficiency and effectiveness. Furthermore, the use of eight current boosters 5 ensures that each current booster has a relatively small output capacity and dimensions, making it readily available on the market and costing no more than a single large-capacity unit. Furthermore, the relatively small dimensions of the eight current boosters make it easy to minimize their footprint within the test site. Therefore, employing multiple current boosters 5 in parallel and arranged symmetrically around the center is also a preferred solution.

[0033] 4. Comprehensive control system for ultra-large current complete test and detection equipment consisting of the initial rectifier inverter source to the large current special test equipment.

[0034] 1. This control system can be placed in a large control cabinet or divided into multiple different control cabinets, depending on the on-site spatial layout, user requirements or habits. It can ensure that different equipment or devices can coordinate with each other during testing and inspection, so that their technology, efficiency, etc. can reach the best state or effect.

[0035] 2. This integrated control system includes the following components:

[0036] 1) Adjust the current to rectify and filter the 380V three-phase circuit and convert it into a single-phase DC circuit control system;

[0037] 2) control system of the inverter system;

[0038] 3) control system of the step-up transformer;

[0039] 4) special electrical test device system for temperature rise or error test of large current or super large current transformer, and loading and unloading control system of the transformer and special large current device, etc;

[0040] 5) auxiliary system, including mutual coordination control and protection device between systems, etc.

[0041] The above several units are combined to form a complete set of super large current test comprehensive control system.

[0042] Five, auxiliary equipment of the complete set

[0043] The auxiliary device includes connection between control systems, temperature measurement equipment, standard transformer for error test, error tester, power factor compensation device, water cooling system added for super large current transformer test, auxiliary electric loading and unloading equipment required for the tested product, and other related auxiliary equipment and systems.

[0044] If other electrical and power equipment is tested and detected in terms of large current or super large current, only the special test and detection device for super large current transformer temperature rise and error test described in the above three items needs to be replaced by a special test and detection device suitable for the tested equipment. According to the structure of the tested equipment (such as super large current circuit breaker, super large capacity step-up transformer, super large current bushing, super large current enclosed busbar, etc.), a special test and detection device is designed to adapt to the test and detection of the tested equipment in all aspects.

[0045] The basic principles and main features of the utility model and the advantages of the utility model are shown and described. It should be understood by those skilled in the art that the utility model is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model can also have various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A single-phase high current generating device, characterized in that: The invention comprises a basic power supply unit and a steady-state current increasing unit, wherein the basic power supply unit comprises a rectifier circuit and an inverter circuit, wherein the rectifier circuit converts the three-phase AC input power supply into a DC power supply, and the inverter circuit converts the DC power supply into an AC power supply, and the output AC power supply is then increased in parallel by N current increasers (5) in the steady-state current increasing unit, wherein N is greater than or equal to 1, and the large current after the increase is applied to the large current bus conductor (8) of the large current test device.

2. A high current transformer test system using the single-phase high current generating device according to claim 1, characterized in that: When N is greater than 1, N current boosters (5) are symmetrically arranged with the large current collecting conductor (8) as the center. The large current test device includes a large bracket (1) of a frame structure, and a large current transformer (6) to be tested is placed at the center position of the lower part of the large bracket (1). The upper end of the large bracket (1) is provided with an upper current collecting plate (9), and the lower end of the large current transformer (6) to be tested is provided with a lower current collecting plate (2). The current booster (5) is connected to the upper current collecting conductor (7) and the lower current collecting conductor (3) respectively. The plate (9) and the lower busbar (2) are electrically connected, and a lifting motor support frame (10) is connected to the top of the large bracket (1), and the lifting motor support frame (10) is connected to the lifting motor (13) and the gearbox (12), and the gearbox (12) is connected to the large current busbar (8) through the screw (11), driving the large current busbar (8) to move up and down, lift and lower, and pass through the inner cavity of the tested large current transformer (6) and contact and conduct with the upper busbar (9) and the lower busbar (2).

3. The large current transformer test system according to claim 2, characterized in that: The large bracket (1) is made of non-magnetic material, and the non-magnetic material includes hard aluminum alloy profiles, non-magnetic stainless steel profiles or non-metallic insulating materials.

4. The large current transformer test system according to claim 2, characterized in that: The large current collecting conductor (8) is a cylindrical structure and is made of T2 copper. The large current collecting conductor (8) has a stable long-term current carrying capacity of more than 55,000A.

5. The large current transformer test system according to claim 2, characterized in that: A liquid cooling channel is added inside the large current bus conductor (8), and the cooling liquid is output to the bus conductor (8) through the external cooling liquid conduit (14), and the cooling liquid injected into the large current bus conductor (8) is output through the external cooling liquid conduit (14) on the other side, thereby forming a flowing liquid cooling system.

6. The large current transformer test system according to claim 2, characterized in that: The system is used for performing temperature rise test and error test of large current transformer.

7. The large current transformer test system according to claim 2, characterized in that: The system is used for performing high-current test and detection on high-current circuit breakers, bushings or busbars.

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