Converter transformer paperboard moisture determination method, equipment, medium and product

Abstract

The invention discloses a converter transformer paperboard moisture determination method and device, a medium and a product, and relates to the field of converter transformer paperboard moisture determination, and the method comprises the steps: obtaining the moisture content in oil under a set temperature, a set electric field intensity and a balance state; according to the water content in the oil, determining the water content of the paperboard under the set temperature and the set electric field intensity by utilizing a paperboard water content calculation model; wherein the paperboard moisture content calculation model is an oil paper moisture balance curve equation considering the electric field intensity-temperature combined effect; the oil paper moisture balance curve equation considering the electric field intensity-temperature combined action is determined based on the oil paper moisture balance curve equation only considering the temperature and the oil paper moisture balance point considering the electric field intensity-temperature combined action; the oil paper moisture balance point under the electric field intensity-temperature combined action is determined by utilizing an electric heating combined action test platform. The method can accurately determine the moisture of the paperboard of the converter transformer.

Description

Technical Field

[0001] The present application relates to the field of determining moisture content of converter transformer paperboard, and in particular to a method, device, medium and product for determining moisture content of converter transformer paperboard. Background Art

[0002] At present, the oil-paper moisture curve of the on-site transformer is the most commonly used method to calculate the moisture content of the paperboard. For AC transformers, the balance curve is not greatly affected by the AC electric field, so only the influence of temperature is considered. However, due to the advantages of DC transmission technology in long-distance and large-capacity transmission, converter transformers are increasingly being put into the power grid. For converter transformers, the DC electric field inside has been proven to have a significant effect on the diffusion and migration of moisture, so it will affect the oil-paper moisture curve. When calculating the moisture content of the paperboard, if the influence of the DC electric field is not considered, an accurate oil-paper moisture curve cannot be obtained, and thus the moisture content of the paperboard cannot be accurately obtained. Summary of the invention

[0003] The purpose of this application is to provide a method, device, medium and product for determining the moisture content of converter transformer paperboard, so as to improve the accuracy of determining the moisture content of converter transformer paperboard.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a method for determining moisture content of a converter transformer paperboard, comprising:

[0006] Obtain the water content in the oil at a set temperature, set electric field strength and equilibrium state;

[0007] According to the moisture content in the oil, the moisture content of the paperboard under the set temperature and the set electric field strength is determined by using a paperboard moisture content calculation model; wherein the paperboard moisture content calculation model is an oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature; the oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature is determined based on the oil-paper moisture balance curve equation considering only the temperature and the oil-paper moisture balance point under the combined effect of electric field strength and temperature; the oil-paper moisture balance point under the combined effect of electric field strength and temperature is determined by using an electric-thermal combined effect test platform.

[0008] Optionally, the electric-thermal combined action test platform comprises: an adjustable DC power supply, an adjustable temperature box and a pressurized electrode;

[0009] The adjustable DC power supply is used to provide voltage to the pressure electrode;

[0010] The adjustable temperature box is used to control the temperature of the experimental environment;

[0011] The voltage-applying electrode is used to apply the voltage provided by the adjustable DC power supply to the insulating sample to generate a uniform electric field.

[0012] Optionally, the electric-thermal combined action test platform further comprises: a protection circuit;

[0013] The protection circuit is arranged between the adjustable DC power supply and the voltage-applying electrode to provide over-current protection and over-voltage protection.

[0014] Optionally, the moisture balance curve equation of oil-paper considering the combined effect of electric field intensity and temperature is:

[0015]

[0016] Where C is the moisture content of the paperboard at a set temperature and a set electric field strength; C oil is the water content in the oil at a set temperature, set electric field strength and equilibrium state; S is the solubility of water in the oil; P S is the saturated water vapor partial pressure; T is the set temperature; k is the electric field coefficient; E is the set electric field strength.

[0017] Optionally, obtaining the water content in the oil at a set temperature, a set electric field strength and a balanced state specifically includes:

[0018] Using formula C oil =RH×S; where C oil It is the moisture content in the oil at a set temperature, set electric field strength and equilibrium state; RH is the relative humidity in the air; S is the solubility of water in the oil.

[0019] Optionally, the oil-paper moisture balance point under the combined action of electric field intensity and temperature is determined using an electric-thermal combined action test platform, specifically including:

[0020] Prepare cardboard samples;

[0021] Setting multiple groups of test conditions; the test conditions are setting the operating temperature and setting the electric field strength that the paperboard is subjected to;

[0022] Based on the paperboard sample, the electric-heat combined action test platform and multiple groups of test conditions, an oil-paper moisture balance test is carried out to determine the oil-paper moisture balance point under the combined action of electric field strength and temperature.

[0023] Optionally, preparing a paperboard sample includes:

[0024] The Weidman paperboard was placed in a blast drying oven at 110°C for 24 hours for drying and dehydration to obtain a dried Weidman paperboard;

[0025] The KI50X converter transformer oil is placed in a vacuum drying oven at 90°C and 100Pa for 48 hours for drying, dehydration and degassing to obtain the dried, dehydrated and degassed KI50X converter transformer oil;

[0026] The dried Weidmann paperboard is placed in a constant temperature and humidity chamber, and the moisture absorption time is controlled to prepare samples with different initial moisture contents to obtain a moisture-absorbing Weidmann paperboard;

[0027] The hygroscopic Weidmann paperboard was immersed in the dried, dehydrated and degassed KI50X converter transformer oil for 24 hours to prepare the paperboard sample.

[0028] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-described methods for determining moisture content of converter transformer paperboard.

[0029] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for determining moisture content of converter transformer paperboard.

[0030] In a fourth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned methods for determining the moisture content of a converter transformer paperboard.

[0031] According to the specific embodiments provided in this application, this application has the following technical effects:

[0032] The present application provides a method, device, medium and product for determining the moisture content of paperboard of a converter transformer, which obtains the moisture content of oil at a set temperature, a set electric field strength and a balanced state; according to the moisture content of the oil, the moisture content of the paperboard under the set temperature and the set electric field strength is determined by using a paperboard moisture content calculation model; wherein the paperboard moisture content calculation model is an oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature; the oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature is determined based on the oil-paper moisture balance curve equation considering only temperature and the oil-paper moisture balance point under the combined effect of electric field strength and temperature; the oil-paper moisture balance point under the combined effect of electric field strength and temperature is determined by using an electric-heat combined effect test platform. The present application can accurately determine the moisture content of paperboard of a converter transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic flow chart of a method for determining moisture content of paperboard of a converter transformer provided in one embodiment of the present application;

[0035] Figure 2 A flow chart was constructed for the moisture balance curve equation of oil-paper considering the combined effect of electric field intensity and temperature;

[0036] Figure 3 This is a schematic diagram of the structure of the electric and thermal combined action test platform;

[0037] Figure 4 This is the curve of the moisture content of the paperboard at 40℃ under different electric field strengths;

[0038] Figure 5 This is a curve diagram showing the change of water content in oil at 40℃ under different electric field strengths;

[0039] Figure 6 It is a curve diagram of the change of water content in paper and oil with equilibrium time under different temperatures and electric fields;

[0040] Figure 7 It is a comparison curve diagram of the moisture balance data points of oil-paper under different temperatures and electric field strengths and Griffin's curves;

[0041] Figure 8 It is the fitting relationship curve diagram of electric field coefficient and temperature;

[0042] Fig. 9 A schematic diagram of the structure of a computer device provided in one embodiment of the present application.

[0043] Figure numerals: 1. adjustable DC power supply; 2. adjustable temperature box; 3. pressurized electrode; 4. protection circuit. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0046] In an exemplary embodiment, Figure 1 As shown, a method for determining the moisture content of a converter transformer paperboard is provided, comprising the following steps:

[0047] S1: Obtain the water content in the oil at a set temperature, set electric field strength and equilibrium state.

[0048] S2: According to the moisture content in the oil, the moisture content of the paperboard under the set temperature and the set electric field strength is determined by using a paperboard moisture content calculation model; wherein the paperboard moisture content calculation model is an oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature; the oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature is determined based on the oil-paper moisture balance curve equation considering only the temperature and the oil-paper moisture balance point under the combined effect of electric field strength and temperature; the oil-paper moisture balance point under the combined effect of electric field strength and temperature is determined by using an electric-thermal combined effect test platform.

[0049] As an optional implementation method, the moisture balance curve equation of oil paper considering the combined effect of electric field intensity and temperature is:

[0050]

[0051] Where C is the moisture content of the paperboard at a set temperature and a set electric field strength; C oil is the water content in the oil at a set temperature, set electric field strength and equilibrium state; S is the solubility of water in the oil; P S is the saturated water vapor partial pressure; T is the set temperature; k is the electric field coefficient; E is the set electric field strength.

[0052] As an optional implementation, S1 specifically includes:

[0053] Using formula C oil =RH×S; where C oil It is the moisture content in the oil at a set temperature, set electric field strength and equilibrium state; RH is the relative humidity in the air; S is the solubility of water in the oil.

[0054] In practical applications, the process of establishing the oil-paper moisture balance curve equation considering the combined effect of electric field intensity and temperature is mainly divided into three steps. The overall process is as follows: Figure 2 shown.

[0055] 1. Construction of an electric-thermal combined action test platform: The test platform supports the adjustment of electric field intensity and temperature, and conducts moisture balance tests on oil-paper samples under different DC electric fields and temperatures.

[0056] 2. Analysis of moisture balance characteristics of oil-paper under DC electric field: Obtain the data on the change of moisture content of oil-paper under different temperatures and different electric field strengths in the experiment, and determine the moisture balance point of oil-paper based on the fact that the moisture content of oil-paper no longer changes within the error range, and obtain a new moisture balance curve of oil-paper.

[0057] 3. Correction of the moisture balance equation of oil-paper: The new moisture balance curve of oil-paper is compared with the moisture balance curve of oil-paper (Griffin's curves) that only considers temperature, and the coupling influence of electric field intensity and temperature is introduced to realize the correction of the moisture balance equation of oil-paper.

[0058] The oil-paper moisture balance curve equation proposed in this application, which takes into account the combined effect of electric field strength and temperature, is used to more accurately calculate the moisture content of paperboard and provide data support for on-site operation and maintenance.

[0059] As an optional implementation method, the oil-paper moisture balance point under the combined action of electric field intensity and temperature is determined using an electric-thermal combined action test platform, specifically including:

[0060] Step 1: Prepare the paperboard sample.

[0061] As an optional embodiment, preparing a paperboard sample specifically includes:

[0062] The Widmanstätten paperboard was placed in a forced air drying oven at 110° C. for 24 hours for drying and dehydration to obtain a dried Widmanstätten paperboard.

[0063] The KI50X converter transformer oil was placed in a vacuum drying oven at 90°C and 100 Pa for 48 hours for drying, dehydration and degassing to obtain the dried, dehydrated and degassed KI50X converter transformer oil.

[0064] The dried Widmann paperboard is placed in a constant temperature and humidity chamber, and the moisture absorption time is controlled to prepare samples with different initial moisture contents to obtain a hygroscopic Widmann paperboard.

[0065] The hygroscopic Weidmann paperboard was immersed in the dried, dehydrated and degassed KI50X converter transformer oil for 24 hours to prepare the paperboard sample.

[0066] 1. Construction of electric and thermal combined action test platform.

[0067] In practical applications, in order to correct the oil-paper moisture balance curve, this application refers to the Oommen method to process and test the paperboard samples. First, the Weidmann paperboard is placed in a 110°C blast drying oven for 24 hours for drying and dehydration, and the KI50X converter transformer oil is placed in a 90°C, 100Pa vacuum drying oven for 48 hours for drying, dehydration and degassing. Then, the dried Weidmann paperboard is placed in a constant temperature and humidity chamber, and the moisture absorption time is controlled to prepare samples with different initial moisture contents. Finally, the hygroscopic Weidmann paperboard is immersed in the KI50X converter transformer oil for 24 hours as the initial sample (paperboard sample).

[0068] Step 2: setting multiple groups of test conditions; the test conditions are setting the operating temperature and setting the electric field strength that the paperboard is subjected to.

[0069] Test conditions: In order to study the effect of DC electric field on the moisture balance of oil-paper, an electric-heat combined test platform was built to ensure that the temperature and electric field are adjustable. By calculating the temperature field and DC electric field inside the converter transformer, it is found that the normal operating temperature range is generally 20℃-80℃, and the DC electric field strength that the paperboard withstands is 0V / mm-30kV / mm. Therefore, in the experimental study, the temperature selection is 40℃, 60℃, and 80℃, and the electric field selection is 0kV / mm (control group), 5kV / mm, 15kV / mm, and 25kV / mm.

[0070] Step 3: Based on the paperboard sample, the electric-heat combined test platform and multiple groups of test conditions, an oil-paper moisture balance test is performed to determine the oil-paper moisture balance point under the combined action of electric field strength and temperature.

[0071] As an optional implementation, the electric-thermal combined action test platform includes: an adjustable DC power supply 1, an adjustable temperature box 2, a pressurized electrode 3 and a protection circuit 4.

[0072] The adjustable DC power supply 1 is used to provide voltage to the pressure electrode 3 .

[0073] The adjustable temperature box 2 is used to control the temperature of the experimental environment.

[0074] The voltage electrode 3 is used to apply the voltage provided by the adjustable DC power supply 1 to the insulating sample.

[0075] The protection circuit 4 is arranged between the adjustable DC power supply 1 and the voltage-applying electrode 3 to provide over-current protection and over-voltage protection.

[0076] In practical applications, the electric and thermal combined action test platform is Figure 3As shown in the figure, the electric-heat combined action test platform is mainly composed of an adjustable DC power supply 1, an adjustable temperature box 2, a pressurized electrode 3 and a protection circuit 4. Among them, the adjustable DC power supply 1 provides a variable voltage for the pressurized electrode 3 to simulate the working state of the insulating material (cardboard sample) under different voltage conditions; the adjustable temperature box 2 is used to accurately control the temperature of the test environment, so as to observe the influence of temperature on the characteristics of the insulating material; the pressurized electrode 3 is a plate-plate electrode with a diameter of 25 mm, which can apply voltage to the insulating material to generate a uniform electric field and test the combined effect of electric field strength and temperature on the performance of the insulating material; the protection circuit 4 provides over-current and over-voltage protection between the adjustable DC power supply 1 and the pressurized electrode 3 to ensure the safety of the test process and the reliability of the equipment.

[0077] These devices are functionally integrated through electrical connections, so that the electric and thermal combined action test platform can stably simulate a variety of electric and thermal combined action test conditions. In addition, the coulometric moisture meter is used for the test of moisture in oil. Each cardboard sample is measured 3 times and the average value is taken. The measurement range is 3μg to 100mg. The moisture content of cardboard is tested using a Karl Fischer moisture analyzer and terahertz spectroscopy. Since the moisture distribution of the cardboard after later diffusion is uneven, and Karl Fischer can only measure the moisture in a local position of the cardboard, and the test process is destructive, at the same time, during the oil-paper moisture balance test, the moisture of the cardboard needs to be measured cyclically. Therefore, this application uses terahertz spectroscopy for non-destructive full-range testing of cardboard moisture. The Karl Fischer measurement range is 10μg to 200mg, and the terahertz spectrum peak range is 0a.u-3200a.u. When conducting the test, the water-containing cardboard sample is placed in the middle of the plate-plate electrode, and parallel pressure is used to support the simultaneous testing of multiple groups of cardboard samples. Starting from the initial sample (0h), the moisture content in the paperboard and oil was measured every 24h until the moisture content stabilized, which indicated that the moisture content of the oil-paper had reached equilibrium.

[0078] 2. Analysis of moisture balance characteristics of oil-paper under DC electric field.

[0079] In this example, cardboard samples with the same initial moisture content and 50 mL of insulating oil were used to carry out orthogonal tests of 0 kV / mm-25 kV / mm at 40°C-80°C. In order to obtain the variation of moisture in paper and moisture in oil under the influence of electric field at different temperatures, this example takes cardboard samples with 0 kV / mm and 25 kV / mm at 40°C as examples, and linearly converts the test results to ensure that the initial moisture content of the cardboard samples is consistent. The variation of cardboard moisture in the cardboard sample group at 40°C under different electric field strengths is shown in the figure. Figure 4As time goes by, the moisture content of the paperboard decreases first, then rises slightly, and finally tends to equilibrium. As the electric field strength increases, the moisture content of the paperboard in equilibrium increases. When the oil is saturated with water, the moisture in the oil will be absorbed back by the paperboard with strong water absorption capacity. Finally, the moisture will transfer back and forth between the oil and paper, and finally reach an equilibrium state.

[0080] In addition, the moisture content of the oil in the cardboard sample group at 40°C changes as follows Figure 5 As shown in the figure, as time goes by, the water content in the oil first increases, then decreases, and finally gradually tends to equilibrium. And as the electric field strength increases, the water content in the oil at equilibrium also tends to increase.

[0081] Similarly, the changes in moisture content of oil paper under different temperatures and electric fields were tested, such as Figure 6 As shown in the figure, the same rules are found. And with the increase of electric field strength, the moisture content in paper and oil in equilibrium increases.

[0082] 3. A new moisture balance curve for oil-paper considering the influence of electric field and temperature and correction of its calculation equation.

[0083] (1) New moisture balance curve of oil paper.

[0084] In order to correct the oil-paper moisture balance curve, this embodiment compares the data of the oil-paper moisture balance point that takes into account the synergistic effect of electric field and temperature with the original oil-paper moisture balance curve (Griffin's curves) generated by the Fessler formula. Based on the oil-paper moisture balance curve (Griffin's curves) and the oil-paper moisture balance points at 40°C, 60°C, and 80°C under different electric field strengths, a new oil-paper moisture balance curve (the oil-paper moisture balance curve that takes into account the combined effect of electric field strength and temperature) is obtained, as shown in FIG. Figure 7 shown.

[0085] Figure 7 It can be seen that the test results of 0kV / mm are basically consistent with the oil-paper moisture balance curve (Griffin's curves) considering only temperature, which proves the effectiveness and accuracy of the test. With the increase of electric field strength, the moisture content in the paper corresponding to the same moisture in the oil increases significantly, which shows that the existence of the electric field causes the paperboard in the strong electric field area to retain more moisture, and finally causes the new moisture balance curve of the oil-paper to rise.

[0086] (2) Equation correction of the new moisture balance curve of oil paper.

[0087] In order to obtain the calculation equation of the new moisture balance curve of oil paper under the influence of electric field strength, this embodiment introduces the electric field coefficient k of the influence of electric field strength on moisture content into the calculation equation of Griffin's curves, and performs curve fitting on the moisture balance points of oil paper under different electric field strengths and temperatures to calculate the k value, while the electric field coefficient k is also affected by temperature. Therefore, the k values ​​calculated at different temperatures are fitted through the test results and Griffin's curves, as shown in FIG. Figure 8 As shown, the unit of the vertical coordinate electric field coefficient is 1.

[0088] Finally, the calculation equation of the oil-paper moisture balance curve considering the combined effect of electric field and temperature can be expressed as:

[0089]

[0090] C oil =RH×S (4)

[0091] The purpose of this embodiment is to calculate the moisture content of oil-paper under the electric field temperature. Generally, only the moisture content in the oil can be monitored on site, and the moisture content in the paperboard cannot be monitored or measured. Therefore, it is necessary to use the formula of Griffin's curves to calculate. However, Griffin's curves only considers the temperature, not the electric field. Therefore, this embodiment conducts an oil-paper moisture balance test under the influence of electric field temperature. By obtaining the moisture balance point data of oil-paper under different electric field strengths and temperatures (multiple groups of moisture content in oil and paper under 216h with different initial moisture contents, about 5-6 groups of data points can fit a new curve), and then correcting it according to the formula of Griffin's curves, while considering the effects of electric field strength and temperature, formula (1) is obtained. When the on-site oil moisture monitoring value is known, the moisture content of the paperboard can be accurately calculated based on the data results of the electric field and temperature fields.

[0092] The new moisture balance curve of oil-paper obtained adds the influence of electric field on the basis of the original Griffin's curves. The calculation equation of the new moisture balance curve of oil-paper shows a significant increase in the moisture content of paperboard calculated under different electric fields and temperatures at the same moisture content in oil, which provides a theoretical calculation equation for the subsequent more accurate moisture evaluation. For example, at 40°C, the moisture content in paper increased by 2.951% and 15.65% at 5kV / mm and 25kV / mm, respectively, and at 80°C, it increased by 5.85% and 32.92%.

[0093] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the above-mentioned method for determining moisture content of paperboard of a converter transformer when executing the computer program.

[0094] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the method for determining the moisture content of paperboard of a converter transformer is implemented.

[0095] In an exemplary embodiment, a computer program product is provided, including a computer program, which implements the above-mentioned method for determining the moisture content of paperboard of a converter transformer when executed by a processor.

[0096] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig. 9 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for determining the moisture content of a converter transformer paperboard is implemented.

[0097] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0098] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0099] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0100] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0101] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for determining the moisture content of converter transformer paperboard, characterized in that: include: Obtain the water content in the oil at a set temperature, set electric field strength and equilibrium state; According to the moisture content in the oil, the moisture content of the paperboard under the set temperature and the set electric field strength is determined by using a paperboard moisture content calculation model; wherein the paperboard moisture content calculation model is an oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature; the oil-paper moisture balance curve equation considering the combined effect of electric field strength and temperature is determined based on the oil-paper moisture balance curve equation considering only the temperature and the oil-paper moisture balance point under the combined effect of electric field strength and temperature; the oil-paper moisture balance point under the combined effect of electric field strength and temperature is determined by using an electric-thermal combined effect test platform.

2. The method for determining the moisture content of converter transformer paperboard according to claim 1, characterized in that: The electric-heat combined action test platform comprises: an adjustable DC power supply, an adjustable temperature box and a pressurized electrode; The adjustable DC power supply is used to provide voltage to the pressure electrode; The adjustable temperature box is used to control the temperature of the experimental environment; The voltage-applying electrode is used to apply the voltage provided by the adjustable DC power supply to the insulating sample to generate a uniform electric field.

3. The method for determining the moisture content of converter transformer paperboard according to claim 1, characterized in that: The electric and thermal combined action test platform also includes: a protection circuit; The protection circuit is arranged between the adjustable DC power supply and the voltage-applying electrode to provide over-current protection and over-voltage protection.

4. The method for determining the moisture content of converter transformer paperboard according to claim 1, characterized in that: The moisture balance curve equation of oil-paper considering the combined effect of electric field intensity and temperature is: Where C is the moisture content of the paperboard at a set temperature and a set electric field strength; C oil is the water content in the oil at a set temperature, set electric field strength and equilibrium state; S is the solubility of water in the oil; P S is the saturated water vapor partial pressure; T is the set temperature; k is the electric field coefficient; E is the set electric field strength.

5. The method for determining the moisture content of converter transformer paperboard according to claim 1, characterized in that: Obtain the water content in the oil at a set temperature, set electric field strength and equilibrium state, including: Using formula C oil =RH×S; where C oil It is the moisture content in the oil at a set temperature, set electric field strength and equilibrium state; RH is the relative humidity in the air; S is the solubility of water in the oil.

6. The method for determining the moisture content of converter transformer paperboard according to claim 1, characterized in that: The electric-heat combined test platform is used to determine the oil-paper moisture balance point under the combined action of electric field intensity and temperature, including: Prepare cardboard samples; Setting multiple groups of test conditions; the test conditions are setting the operating temperature and setting the electric field strength that the paperboard is subjected to; Based on the paperboard sample, the electric-heat combined action test platform and multiple groups of test conditions, an oil-paper moisture balance test is carried out to determine the oil-paper moisture balance point under the combined action of electric field strength and temperature.

7. The method for determining the moisture content of converter transformer paperboard according to claim 6, characterized in that: Prepare paperboard samples, including: The Weidman paperboard was placed in a blast drying oven at 110°C for 24 hours for drying and dehydration to obtain a dried Weidman paperboard; The KI50X converter transformer oil is placed in a vacuum drying oven at 90°C and 100Pa for 48 hours for drying, dehydration and degassing to obtain the dried, dehydrated and degassed KI50X converter transformer oil; The dried Weidmann paperboard is placed in a constant temperature and humidity chamber, and the moisture absorption time is controlled to prepare samples with different initial moisture contents to obtain a moisture-absorbing Weidmann paperboard; The hygroscopic Weidmann paperboard was immersed in the dried, dehydrated and degassed KI50X converter transformer oil for 24 hours to prepare the paperboard sample.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for determining moisture content of converter transformer paperboard according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for determining the moisture content of the converter transformer paperboard according to any one of claims 1 to 7 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for determining the moisture content of the converter transformer paperboard according to any one of claims 1 to 7 is implemented.

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