Corrosion resistance testing device and method

Abstract

The invention provides a corrosion resistance testing device and method.The corrosion resistance testing device comprises a testing cavity, a winding fixing mechanism, a sensing mechanism, a heating mechanism and a supply mechanism. By arranging the temperature sensing assembly, the magnetic sensing assembly, the oxygen supply unit, the sulfide supply unit and the like, the corrosion condition of the winding in the transformer is researched by combining multiple influence factors such as temperature, a magnetic field, oxygen and sulfide. Therefore, factors and mechanisms that the winding is influenced by corrosion can be mastered by the system, and the method has important significance for long-term safe and stable operation of the power transformer.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a corrosion resistance testing device and method capable of combining multiple testing factors. Background Art

[0002] Power transformer oil contains many trace elements, among which sulfur in substances such as mercaptans (RSH), sulfides (DBS), and thiophene is believed to be related to many transformer accidents. A large number of related transformer failure studies have found that the corrosion of insulating oil sulfides on copper windings 1 will form cuprous sulfide (Cu2S) precipitation on the surface of winding insulation paper, which is also recognized as one of the core causes of transformer corrosion failures.

[0003] Specifically, the dielectric properties of the oil-paper insulation on the winding surface corroded by sulfides will be significantly reduced, which can easily induce winding turn-to-turn discharge faults. Minor turn-to-turn discharge faults are not easy to identify, but when they further develop into interlayer or even interphase discharges, they may even cause serious consequences such as transformer damage.

[0004] However, the current research on transformer winding corrosion has problems such as poor systematicity, limited test conditions, and inaccurate analysis results. Therefore, it is necessary to propose further solutions to the above problems. Summary of the invention

[0005] The present invention aims to provide a corrosion resistance testing device and method to overcome the deficiencies in the prior art.

[0006] In order to solve the above technical problems, the technical solution of the present invention is:

[0007] A corrosion resistance testing device, which can be used for corrosion resistance testing of windings in transformers; it comprises: a testing chamber, a winding fixing mechanism, a sensing mechanism, a heating mechanism and a supply mechanism;

[0008] The winding fixing mechanism comprises: a fixing column and an iron core assembly; one end of the fixing column extends into the test cavity; the winding can be wound on the fixing column and located in the test cavity; the iron core assembly is located in the fixing column;

[0009] The sensing mechanism comprises: a temperature sensing component and a magnetic sensing component; the temperature sensing component and the magnetic sensing component are integrated in the fixing column, the temperature sensing component can sense the temperature inside the test cavity; the magnetic sensing component can sense the magnetic field strength inside the test cavity;

[0010] The heating mechanism comprises a heater, and the heater extends into the test cavity; the supply mechanism comprises: an oxygen supply unit and a sulfide supply unit, and the oxygen supply unit and the sulfide supply unit are respectively connected to the test cavity.

[0011] As an improvement of the corrosion resistance testing device of the present invention, an insulating layer is further provided between the winding and the fixing column.

[0012] As an improvement of the corrosion resistance testing device of the present invention, the core assembly can be lifted and lowered in the fixing column to change the overlapping range between the core assembly and the winding.

[0013] As an improvement of the corrosion resistance testing device of the present invention, the winding fixing mechanism also includes a lifting component; the lifting component includes: a screw and a lifting controller, one end of the screw is connected to the core component, and the other end is connected to the lifting controller.

[0014] As an improvement of the corrosion resistance testing device of the present invention, the winding fixing mechanism also includes a winding current loop control module, which includes: a first terminal, a second terminal and an AC power supply; the first terminal and the second terminal are arranged on the test cavity, and the AC power supply is connected in series with the winding through the first terminal and the second terminal.

[0015] As an improvement of the corrosion resistance testing device of the present invention, the temperature sensing assembly includes a plurality of temperature sensors; the number n of the plurality of temperature sensors satisfies: 10≤n≤20; the plurality of temperature sensors are evenly spaced along the axial direction on the inner side wall of the fixed column.

[0016] As an improvement of the corrosion resistance testing device of the present invention, the magnetic sensing assembly includes a plurality of magnetic sensors; the number m of the plurality of magnetic sensors satisfies: 10≤m≤20; the plurality of magnetic sensors are evenly spaced along the axial direction on the inner side wall of the fixed column.

[0017] As an improvement of the corrosion resistance testing device of the present invention, the plurality of temperature sensors and the plurality of magnetic sensors are all connected with independent signal transmission lines.

[0018] As an improvement of the corrosion resistance testing device of the present invention, the heater is a temperature-controlled heating rod; the working state of the temperature-controlled heating rod is controlled by the host of the device.

[0019] As an improvement of the corrosion resistance test device of the present invention, the oxygen supply unit includes: an oxygen tank and an oxygen control valve; the oxygen tank is connected to the test chamber through a first pipeline, and the oxygen control valve is arranged on the first pipeline;

[0020] The sulfide supply unit comprises: a sulfide storage tank and a sulfide control valve; the sulfide storage tank is connected to the test chamber through a second pipeline, and the sulfide control valve is arranged on the second pipeline.

[0021] In order to solve the above technical problems, the technical solution of the present invention is:

[0022] A corrosion resistance testing method, the corrosion resistance testing method is based on the corrosion resistance testing device according to any one of claims 1 to 10; the method comprises the following steps:

[0023] S1. Test environment configuration, which includes:

[0024] Adjusting the height of the core assembly to make it consistent with the center height of the winding in the vertical direction;

[0025] injecting oxygen and sulfide with preset concentrations into the oil inside the test chamber;

[0026] heating the oil in the test chamber to a preset temperature;

[0027] S2. Winding corrosion test, which includes:

[0028] Pass alternating current into the current loop where the winding is located, and record the corresponding magnetic field information at the same time;

[0029] Keep the power on according to the preset test time and temperature;

[0030] S3. Test result analysis, including:

[0031] The oil in the test chamber is subjected to oil chromatography analysis to analyze the concentration of copper and sulfur elements therein;

[0032] Combined with the recorded magnetic field information, image analysis was performed on the amount and distribution characteristics of the deposits on the winding surface, and the characteristics of the deposit generation process on the winding surface affected by the magnetic field were obtained;

[0033] After the winding is cleaned and dried, the weight change of the winding before and after the test is measured, and the corrosion rate of the winding under the current test conditions is calculated based on the weight change.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention provides a temperature sensor component, a magnetic sensor component, an oxygen supply unit and a sulfide supply unit, thereby realizing the study of the corrosion of the transformer winding by combining multiple influencing factors such as temperature, magnetic field, oxygen, sulfide, etc. Therefore, it is helpful to systematically grasp the factors and mechanisms affecting the corrosion of the winding, which is of great significance to the long-term safe and stable operation of the power transformer.

[0036] The present invention also optimizes the design of the winding fixing mechanism, which can not only assist the installation and fixing of the core assembly, but also prevent the core assembly from being corroded and thus affecting the test results. It can also assist the installation and fixing of the temperature sensor assembly and the magnetic sensor assembly, so that it is no longer necessary to arrange the sensor assembly between the turns of the winding, etc., thereby affecting the precipitation adhesion or deposition process occurring on the winding surface during the sulfur corrosion test, resulting in deviations in the test results.

[0037] Finally, the present invention can adjust the core assembly in the vertical direction by setting a lifting assembly, thereby broadening the adjustment method and range of the magnetic induction intensity of the winding. It is no longer simply dependent on changing the current value of the winding itself to excite the magnetic field, thereby improving the flexibility of the test device and extending its scope of application.

[0038] In addition, by setting up the lifting assembly, the range of the overlapping part of the core assembly and the winding can be flexibly controlled, so that the upper and lower parts of the same copper winding 1 are respectively under the influence of two magnetic fields with extremely different intensities in the same experimental environment, thereby improving the scientific nature of the design of the test device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 It is a structural schematic diagram of an embodiment of a corrosion resistance testing device of the present invention;

[0041] Figure 2 for Figure 1 Schematic diagram of the internal structure of the middle fixed column;

[0042] Figure 3 for Figure 1 A top view of the middle fixed column;

[0043] Figure 4 This is a schematic diagram of the connection relationship between the host and other control modules in one embodiment of the corrosion resistance testing device of the present invention. DETAILED DESCRIPTION

[0044] 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 only 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.

[0045] An embodiment of the present disclosure provides a corrosion resistance testing device, which can combine multiple factors that affect winding corrosion to study the corrosion of the winding. Therefore, it is helpful to systematically grasp the factors and mechanisms that affect the corrosion of the winding, which is of great significance to the long-term safe and stable operation of the power transformer. In addition, the influencing factors in this device are flexibly adjusted and the mechanisms are independent of each other, which is not only conducive to analyzing the influence of single factors such as magnetic induction intensity on the sulfur corrosion process of copper windings, but also can ensure the validity of the test results under the combination of multiple factors. In this embodiment, the winding is specifically a spiral coil wound by a copper wire with insulating oil paper evenly and densely wound on the outside.

[0046] like Figure 1 As shown, the corrosion resistance testing device of this embodiment includes: a testing chamber 81 , a winding fixing mechanism, a sensing mechanism, a heating mechanism, a supply mechanism and a host 22 .

[0047] like Figure 4 As shown, the host 22 is used to control the operation of the corrosion resistance test device, for example, to control the lifting and lowering of the core assembly 2 in the winding fixing mechanism, the collection of temperature information and magnetic field information, the supply of oxygen and sulfide, etc. In this embodiment, the host 22 can be an industrial control computer.

[0048] The test chamber 81 is used to provide a test space for the corrosion resistance test of the copper winding 1, and the test chamber 81 can be filled with transformer oil used for the test. In one embodiment, the test chamber 81 can be a steel box, and a steel top cover 82 is provided on the top of the box. The steel top cover 82 is fastened to the box by bolts.

[0049] In addition, an oil circulation control module 14 is connected to the outside of the box, and the oil circulation control module 14 includes an oil pump motor. The oil pump motor is connected to the bottom position of the test chamber 81 through a circulation pipeline, and is connected to the top position of the test chamber 81 through another circulation pipeline. At the same time, the oil pump motor is connected to the industrial control computer through an optical fiber signal line. In this way, during the test phase, when the oil pump motor is started by the industrial control computer, it is beneficial to fully mix the transformer oil in the test chamber 81 with sulfide and oxygen.

[0050] One of the functions of the winding fixing mechanism is to realize the installation and fixation of the winding. The winding fixing mechanism includes: a fixing column 4 and an iron core assembly 2. Among them, one end of the fixing column 4 extends into the test cavity 81, and the part of the fixing column 4 extending into the test cavity 81 forms the main body of the winding winding and fixing. Correspondingly, the winding can be wound on the fixing column 4 and located in the test cavity 81. In addition, an insulating layer 18 is also provided between the winding and the fixing column 4. In one embodiment, the insulating layer is an insulating paper tube with a thickness of 2 to 4 mm.

[0051] During the winding test, it is necessary to pass AC power through the winding. In order to meet the requirements of the test, the winding fixing mechanism also includes a winding current loop control module 20, which includes: a first wiring terminal 31, a second wiring terminal 32 and an AC power supply. The first wiring terminal 31 and the second wiring terminal 32 are arranged on the steel top cover 82 of the test cavity 81, and the AC power supply is connected in series with the winding through the first wiring terminal 31 and the second wiring terminal 32. Thus, the AC power supply can continuously provide a constant AC voltage or current, and the output frequency of the AC power supply can preferably be 50Hz.

[0052] The core assembly 2 can more realistically simulate the magnetic field environment in which the copper winding 1 of the transformer is running, making the test research results closer to the actual situation, because after the core is inserted, the magnetic field around the copper winding 1 will be greatly improved. In order to assist in the fixation of the core assembly 2, the fixing column 4 is set to a hollow tube structure, and the material of the hollow tube is tempered glass. The core assembly 2 is located in the hollow tube. The core assembly 2 is made of silicon steel sheets of different sizes stacked tightly and is set to a cylindrical structure that imitates the shape of the hollow tube. The inner diameter of the hollow tube cavity is 20 to 40 mm longer than the circumferential diameter of the core cross section to facilitate the lifting of the core and reserve installation space for the sensor.

[0053] The hollow tube made of glass fiber reinforced plastic has the following advantages: 1) the core assembly 2 is physically separated from the external copper winding 1, thus preventing the chemical corrosion of the silicon steel sheet from affecting the sulfur corrosion test result of the copper winding 1; 2) a place for installing and fixing the temperature sensor and the magnetic sensor is provided, and it is no longer necessary to arrange the sensor between the turns of the copper winding 1, thereby affecting the adhesion or deposition process of the precipitate on the surface of the winding during the sulfur corrosion test, resulting in deviation of the test result; 3) the tempered glass material has weak shielding effect on the magnetic field, and the core assembly 2 inside the hollow tube has a strong aggregation effect on the magnetic field around the energized copper winding 1.

[0054] Furthermore, the core assembly 2 can be lifted and lowered in the fixing column 4 to change the overlapping range between the core assembly 2 and the winding. It is believed that by inserting the core assembly 2 that can be adjusted in the vertical direction, the adjustment method and range of the magnetic induction intensity of the copper winding 1 can also be broadened, and the magnetic field is no longer simply excited by changing the current value of the copper winding 1 itself, which makes the test device more flexible and has a wider range of applications.

[0055] Correspondingly, the winding fixing mechanism also includes a lifting component; the lifting component includes: a screw 5 and a lifting controller 6, one end of the screw 5 is connected to the core component 2, and the other end is connected to the lifting controller 6. When working, the lifting controller 6 controls the vertical lifting of the core component 2 through the rotation of the motor. The lifting component can flexibly control the range of the overlapping part of the core component 2 and the winding, so that the upper and lower parts of the same copper winding 1 are under the influence of two magnetic fields with extremely different intensities in the same experimental environment, thereby improving the scientific nature of the test device design. It also makes the test evaluation analysis, especially the influence of the magnetic field on the sulfur corrosion process of the copper winding 1 obtained by the test and the mechanism more convincing.

[0056] like Figure 2 As shown, the sensing mechanism includes: a temperature sensing component and a magnetic sensing component; the temperature sensing component and the magnetic sensing component are integrated in the fixing column 4, the temperature sensing component can sense the temperature inside the test cavity 81; the magnetic sensing component can sense the magnetic field strength inside the test cavity 81. By setting the above temperature sensing component and magnetic sensing component, the corrosion of the winding in the transformer can be studied by combining temperature and magnetic field.

[0057] The temperature sensing assembly includes a plurality of temperature sensors 161-16n; the number n of the plurality of temperature sensors 161-16n satisfies: 10≤n≤20; the plurality of temperature sensors 161-16n are evenly spaced along the axial direction on the inner side wall of the fixed column 4. The magnetic sensing assembly includes a plurality of magnetic sensors 171-17m; the number m of the plurality of magnetic sensors 171-17m satisfies: 10≤m≤20; the plurality of magnetic sensors 171-17m are evenly spaced along the axial direction on the inner side wall of the fixed column 4. With such an arrangement, it is no longer necessary to arrange the sensor at the turns of the copper winding 1, etc., thereby affecting the deposition or deposition process of the precipitate on the winding surface during the sulfur corrosion test, resulting in a deviation in the test result.

[0058] Among them, the temperature sensor and magnetic sensor are both patch sensors, so that they can be evenly spaced along the axial direction on the inner wall of the fixed column 4. The temperature sensors are equipped with connecting signal transmission lines, and all signal output lines are connected to the external temperature monitoring module 19 through the flange through-disks 71 and 72 on the side of the rising seat 7 on the upper part of the fixed seat. The signal transmission line is made of oil-resistant and heat-resistant material, preferably a conductor with ceramic, glass fiber or polyimide as the main component of the surface material. The temperature monitoring module 19 is further connected to the industrial control computer to send real-time temperature information to the host computer, so as to facilitate the system to control the configuration of various test conditions of the test device.

[0059] like Figure 3As shown, the magnetic sensor can monitor the magnetic induction intensity in the vertical and horizontal directions at the same time. The vertical direction refers to the direction of the central axis of the copper winding 1, and the horizontal direction refers to the tangent direction at the intersection of each sensor and the circumference of the horizontal cross-section circle of the hollow tube cavity. The magnetic sensors are equipped with connecting signal transmission lines, and all signal output lines are connected to the external magnetic field monitoring module 21 through the side flange through-disks 71 and 72 of the rising seat 7 on the upper part of the fixed seat. The above-mentioned signal transmission line is made of oil-resistant and heat-resistant material, preferably with ceramic, glass fiber or polyimide as the main component of the surface material. The magnetic field monitoring module 21 is further connected to the industrial control computer to send real-time magnetic field information to the host computer, which is convenient for the system to control the configuration of various test conditions of the test device.

[0060] The heating mechanism is used to maintain the preset test temperature inside the test cavity 81. Specifically, the heating mechanism includes a heater 9, which extends into the test cavity 81. In one embodiment, the heater 9 is a temperature-controlled heating rod, which is installed on the steel top cover 82 and controlled by an industrial control computer.

[0061] The supply mechanism includes an oxygen supply unit and a sulfide supply unit, and the oxygen supply unit and the sulfide supply unit are respectively connected to the test chamber 81. By setting the oxygen supply unit and the sulfide supply unit, the corrosion of the transformer winding by oxygen and sulfide is studied.

[0062] The oxygen supply unit includes: an oxygen tank 13 and an oxygen control valve 12; the oxygen tank 13 is connected to the test chamber 81 through a first pipeline, and the oxygen control valve 12 is arranged on the first pipeline. The oxygen control valve 12 is an electronic flow control valve, which is connected to the industrial control computer through an oxygen control device; the oxygen control valve 12 is fixedly connected to the side wall of the test chamber 81 through the first pipeline and communicates with the internal space of the chamber; the oxygen control valve 12 is connected to the industrial control computer through an optical fiber signal line, and the industrial control computer accurately controls the amount of oxygen taken according to the test needs.

[0063] The sulfide supply unit includes: a sulfide storage tank 11 and a sulfide control valve 10; the sulfide storage tank 11 is connected to the test chamber 81 through a second pipeline, and the sulfide control valve 10 is arranged on the second pipeline. A plurality of mutually isolated small chambers are arranged inside the sulfide storage tank 11, which are used to separately store different types of sulfides, preferably mercaptan, dibenzyl sulfide, dibenzyl sulfide, etc. The sulfide control valve 10 is correspondingly arranged in plurality, and each sulfide control valve 10 is independently connected to the corresponding small chamber. The sulfide control valve 10 is connected to the industrial control computer through an optical fiber signal line. The industrial control computer controls the on-off of the sulfide control valve 10 according to the test needs, so as to quantitatively control the single use of different types of sulfides in each small chamber.

[0064] Based on the corrosion resistance testing device described in the above embodiment, the present invention also provides a corrosion resistance testing method, which performs corresponding testing steps through the above corrosion resistance testing device.

[0065] The corrosion resistance testing method of this embodiment includes the following steps:

[0066] S1. Test environment configuration, which includes:

[0067] S11, adjusting the height of the core assembly so that it is consistent with the center height of the winding in the vertical direction;

[0068] S12, injecting oxygen and sulfide with preset concentrations into the oil inside the test chamber;

[0069] S13. Heat the oil in the test chamber to a preset temperature.

[0070] Steps S11 to S13 are described in detail below.

[0071] The height of the core assembly is adjusted by the industrial control computer to make the core assembly and the copper winding 1 have the same center height in the vertical direction; the test cavity and the hollow tube are filled with transformer oil, and according to the specific requirements of the test plan, the industrial control computer generally controls the test conditions: first, a certain amount of oxygen and sulfide are respectively injected into the oil in the test cavity, wherein the oxygen concentration is preferably 1% to 5%, and the concentration of various sulfides is preferably 0.2 to 10 ppm; the temperature control heater is turned on to heat the oil to the set temperature value, preferably 80°C, 100°C, 120°C and 140°C; while keeping the temperature control heater turned on, the oil pump motor is turned on to fully mix the transformer oil in the test cavity with the sulfide and oxygen

[0072] S2. Winding corrosion test, which includes:

[0073] S21, passing alternating current into the current loop where the winding is located, and recording corresponding magnetic field information at the same time;

[0074] S22. Keep the power on according to the preset test time and temperature.

[0075] Steps S21 and S22 are described in detail below.

[0076] Control the current loop where the copper winding 1 is connected, control the loading of a stable alternating current, the frequency is preferably 50, 100, 150 Hz, and the current density is preferably 1-3 A / mm 2, and record the magnetic field information of the magnetic sensors 171~17m at this time; place the test device in an area with good heat dissipation and ventilation, and keep it powered on for a certain period of time. The test time is preferably 3 to 12 weeks; during the test, when the temperature exceeds the test preset stability, the industrial control computer 22 will automatically turn off the temperature control heater. On the contrary, when the oil temperature is too low, the temperature control heater will be turned on to keep the temperature stable at the preset value ±2°C.

[0077] S3. Test result analysis, including:

[0078] S31, performing oil chromatography analysis on the oil in the test cavity to analyze the concentrations of copper and sulfur elements therein;

[0079] S32, combining the recorded magnetic field information, performing image analysis on the amount and distribution characteristics of the deposits on the winding surface, and obtaining the characteristics of the deposit generation process on the winding surface affected by the magnetic field;

[0080] S33. After cleaning and drying the winding, measure the weight change of the winding before and after the test, and calculate the corrosion rate of the winding under the current test conditions based on the weight change.

[0081] Steps S31 to S33 are described in detail below.

[0082] 1) Oil chromatographic analysis: After each test, take an oil sample through the oil drain valve 15 for oil analysis, and use chromatography to analyze the specific content concentration of copper and sulfur elements in the oil;

[0083] 2) Image analysis: Open the steel cover of the test chamber, take out the copper winding 1, and record the amount and distribution characteristics of the deposits on the upper, middle and lower insulating oil paper surfaces of the copper winding 1 in detail in the form of images. Combined with the quantitative magnetic field information of each magnetic sensor, the characteristics of the sulfur corrosion deposit generation process of the copper winding 1 affected by the magnetic field can be analyzed. The more deposits on the surface, the more serious the corrosion of the copper winding 1. Since the magnetic induction intensity at different positions of the winding is quite different, such as the large difference in the amount of deposits generated at different positions on the surface of the insulating oil paper, it indicates that the magnetic field has a great influence on the sulfur corrosion process of the copper winding 11, otherwise it means that there is no obvious influence.

[0084] 3) Weight loss analysis: Separate the winding and the surface insulating oil paper, and use the weight loss method to evaluate the corrosion rate of the copper winding 1: Clean the copper winding 1 thoroughly with acetone and then dry it, measure the weight change of the copper winding 1 before and after the test, and calculate the corrosion rate of the copper winding 1 under the current test configuration conditions. The greater the weight loss of the copper winding 1, the faster the corrosion rate, and vice versa.

[0085] Finally, comparative analysis of control variables was performed.

[0086] Taking the type and content of sulfide added to the test chamber, oxygen content, magnetic induction intensity, test temperature value, winding current value and current frequency, test time and other factors as variables, strictly follow the principle of controlled variable method to conduct group tests, and repeat steps S1-S3 to complete the multi-factor combined sulfur corrosion test of transformer copper winding 1. According to the test results, the influence degree and mechanism of each factor on the sulfur corrosion rate and process of copper winding 1 when configured alone or in combination can be evaluated and analyzed.

[0087] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0088] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A corrosion resistance testing device, characterized in that: The device is used for corrosion resistance testing of windings in transformers; It includes: a test chamber, a winding fixing mechanism, a sensing mechanism, a heating mechanism and a supply mechanism; The winding fixing mechanism comprises: a fixing column and an iron core assembly; one end of the fixing column extends into the test cavity; the winding can be wound on the fixing column and located in the test cavity; the iron core assembly is located in the fixing column; The sensing mechanism comprises: a temperature sensing component and a magnetic sensing component; the temperature sensing component and the magnetic sensing component are integrated in the fixing column, the temperature sensing component can sense the temperature inside the test cavity; the magnetic sensing component can sense the magnetic field strength inside the test cavity; The heating mechanism comprises a heater, and the heater extends into the test cavity; the supply mechanism comprises: an oxygen supply unit and a sulfide supply unit, and the oxygen supply unit and the sulfide supply unit are respectively connected to the test cavity.

2. The corrosion resistance testing device according to claim 1, characterized in that: An insulating layer is also provided between the winding and the fixing column.

3. The corrosion resistance testing device according to claim 1, characterized in that: The core assembly can be lifted and lowered in the fixing column to change the overlapping range between the core assembly and the winding.

4. The corrosion resistance testing device according to claim 3, characterized in that: The winding fixing mechanism also includes a lifting component; the lifting component includes: a screw rod and a lifting controller, one end of the screw rod is connected to the core component, and the other end is connected to the lifting controller.

5. The corrosion resistance testing device according to claim 1, characterized in that: The winding fixing mechanism also includes a winding current loop control module, which includes: a first terminal, a second terminal and an AC power supply; the first terminal and the second terminal are arranged on the test cavity, and the AC power supply is connected in series with the winding through the first terminal and the second terminal.

6. The corrosion resistance testing device according to claim 1, characterized in that: The temperature sensing assembly includes a plurality of temperature sensors; the number n of the plurality of temperature sensors satisfies: 10≤n≤20; the plurality of temperature sensors are evenly spaced along the axial direction and arranged on the inner side wall of the fixing column.

7. The corrosion resistance testing device according to claim 1, characterized in that: The magnetic sensing assembly includes a plurality of magnetic sensors; the number m of the plurality of magnetic sensors satisfies: 10≤m≤20; the plurality of magnetic sensors are evenly spaced along the axial direction and arranged on the inner side wall of the fixing column.

8. The corrosion resistance testing device according to claim 6 or 7, characterized in that: The plurality of temperature sensors and the plurality of magnetic sensors are all connected with independent signal transmission lines.

9. The corrosion resistance testing device according to claim 1, characterized in that: The heater is a temperature-controlled heating rod; the working state of the temperature-controlled heating rod is controlled by the host of the device.

10. The corrosion resistance testing device according to claim 1, characterized in that: The oxygen supply unit comprises: an oxygen tank and an oxygen control valve; the oxygen tank is connected to the test chamber through a first pipeline, and the oxygen control valve is arranged on the first pipeline; The sulfide supply unit comprises: a sulfide storage tank and a sulfide control valve; the sulfide storage tank is connected to the test chamber through a second pipeline, and the sulfide control valve is arranged on the second pipeline.

11. A corrosion resistance testing method, characterized in that: The corrosion resistance test method is based on the corrosion resistance test device according to any one of claims 1 to 10; the method comprises the following steps: S1. Test environment configuration, which includes: Adjusting the height of the core assembly to make it consistent with the center height of the winding in the vertical direction; injecting oxygen and sulfide with preset concentrations into the oil inside the test chamber; heating the oil in the test chamber to a preset temperature; S2. Winding corrosion test, which includes: Pass alternating current into the current loop where the winding is located, and record the corresponding magnetic field information at the same time; Keep the power on according to the preset test time and temperature; S3. Test result analysis, including: The oil in the test chamber is subjected to oil chromatography analysis to analyze the concentration of copper and sulfur elements therein; Combined with the recorded magnetic field information, image analysis was performed on the amount and distribution characteristics of the deposits on the winding surface, and the characteristics of the deposit generation process on the winding surface affected by the magnetic field were obtained; After the winding is cleaned and dried, the weight change of the winding before and after the test is measured, and the corrosion rate of the winding under the current test conditions is calculated based on the weight change.

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