Thermal aging test device and system

Abstract

The application relates to a heat aging test device and system. The heat aging test device comprises a test box for accommodating an insulation sample; a temperature control assembly connected with the test box and used for regulating the internal temperature of the test box; and a measurement and control assembly partially located in the test box and partially located outside the test box, wherein the measurement and control assembly comprises at least two measurement modules and a selection module, the selection module is connected with each measurement module and the insulation sample, and the selection module is used for selecting a passageway between the measurement module and the insulation sample; the measurement module is used for measuring the dielectric property parameters of the insulation sample under the internal temperature in the case of electrical connection with the insulation sample; and each measurement module measures different dielectric property parameters. The heat aging test device can accurately reflect the operation condition of cable insulation materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid, in particular to a thermal aging test device and system. BACKGROUND

[0002] As the main medium for power transmission in the power system, power cables play an important role in the power system. In the actual operation process, power cables will continuously bear the action of thermal stress. The insulation performance of power cables will inevitably deteriorate under the long-term action of thermal stress.

[0003] Therefore, it is necessary to conduct thermal aging tests on power cables to observe the thermal aging of insulation materials under different conditions. The test conditions and performance parameters of the test device in the related art are relatively single, and cannot accurately reflect the operating conditions of cable insulation materials. SUMMARY

[0004] Therefore, it is necessary to conduct thermal aging tests on power cables to observe the thermal aging of insulation materials under different conditions. The test conditions and performance parameters of the test device in the related art are relatively single, and cannot accurately reflect the operating conditions of cable insulation materials.

[0005] In a first aspect, the present application provides a thermal aging test device, which comprises:

[0006] A test box for accommodating an insulation sample;

[0007] A temperature control assembly connected to the test box for regulating the internal temperature of the test box;

[0008] A measurement and control assembly, part of which is located in the test box and the rest is located outside the test box. The measurement and control assembly comprises at least two measurement modules and a selection module. The selection module is connected to each measurement module and the insulation sample. The selection module is used to select the path between the measurement module and the insulation sample. The measurement module is used to measure the dielectric performance parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample. Each measurement module measures different dielectric performance parameters.

[0009] In one embodiment, the measurement and control assembly comprises at least two of the conductance measurement module, the space charge measurement module and the dielectric loss measurement module; wherein,

[0010] The conductance measurement module is used to determine the conductance parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample;

[0011] The space charge measurement module is used to determine the space charge parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample;

[0012] The dielectric loss measurement module is configured to determine the dielectric loss parameter of the insulation sample at the internal temperature when the insulation sample is electrically connected.

[0013] In one of the embodiments, the device further comprises:

[0014] An insulation shielding assembly is connected with the insulation sample, the insulation shielding assembly is different from the extending direction of the insulation sample, the conductance measurement module and the space charge measurement module are located at a first side of the insulation shielding assembly, the dielectric loss measurement module is located at a second side of the insulation shielding assembly, the first side and the second side of the insulation shielding assembly are opposite sides in the extending direction of the insulation sample, and the insulation shielding assembly is configured to shield signal interference between the conductance measurement module, the space charge measurement module and the dielectric loss measurement module.

[0015] In one of the embodiments, the conductance measurement module comprises:

[0016] A first pressure electrode is connected with one side of the insulation sample and a first end of the selection module, respectively;

[0017] A first measurement electrode is configured to ground the other side of the insulation sample;

[0018] A first direct current power supply is connected with a second end of the selection module at a first end thereof and grounded at a second end thereof, and the first direct current power supply is configured to provide a direct current stabilized voltage signal;

[0019] A first measurement unit is connected with the first measurement electrode and configured to determine the conductance parameter of the insulation sample at the internal temperature by measuring the current information of the insulation sample when the selection module is turned on to connect the first direct current power supply with the first pressure electrode.

[0020] In one of the embodiments, the space charge measurement module comprises:

[0021] A second pressure electrode is connected with one side of the insulation sample and a third end of the selection module, respectively;

[0022] A second measurement electrode is configured to ground the other side of the insulation sample;

[0023] a power supply unit comprising a second direct current power supply and a pulse power supply, a first end of the second direct current power supply and a first end of the pulse power supply are connected with a fourth end of the selection module respectively, a second end of the second direct current power supply and a second end of the pulse power supply are grounded respectively, the second direct current power supply is used for providing the direct current signal, and the pulse power supply is used for providing the pulse signal;

[0024] a second measurement unit connected with the second measurement electrode, used for determining the space charge parameter of the insulating sample at the internal temperature by measuring the acoustic pulse signal generated by the insulating sample under the joint action of the direct current signal and the pulse signal in the case that the second direct current power supply and the pulse power supply are turned on by the selection module and connected with the second pressure electrode respectively.

[0025] In one of the embodiments, the space charge measurement module further comprises:

[0026] a protection resistor, the first end of the second direct current power supply is connected with the fourth end of the selection module through the protection resistor;

[0027] an isolation capacitor, the first end of the pulse power supply is connected with the fourth end of the selection module through the isolation capacitor.

[0028] In one of the embodiments, the dielectric loss measurement module comprises an alternating current power supply, a first bridge arm, a second bridge arm and a third measurement unit, a first end of the alternating current power supply is connected with a midpoint of the second bridge arm, the selection module is connected with a second end of the alternating current power supply and a midpoint of the first bridge arm respectively, the first bridge arm, the second bridge arm and the third measurement unit are connected with each other in parallel, the first bridge arm comprises the insulating sample and a constant value capacitor connected in series, a connection point between the insulating sample and the constant value capacitor is the midpoint of the first bridge arm, the second bridge arm comprises an adjustable resistor and an equivalent unit connected in series, the equivalent unit comprises a constant value resistor and an adjustable capacitor connected in parallel, a connection point between the adjustable resistor and the equivalent unit is the midpoint of the second bridge arm, the alternating current power supply is used for providing the pulse signal; the third measurement unit is used for determining the dielectric loss parameter of the insulating sample according to a capacitance value of the adjustable capacitor and a resistance value of the constant value resistor in the case that the selection module turns on the alternating current power supply and the midpoint of the first bridge arm, and the voltages at both ends of the first bridge arm and the second bridge arm are equal.

[0029] In one of the embodiments, the thermal aging test device further comprises at least one protection electrode, and the insulating sample is grounded through the protection electrode.

[0030] In one of the embodiments, the temperature control assembly comprises:

[0031] a heating module connected with the test box, used for generating heat;

[0032] a cooling module, connected with the test box, for transmitting cooling to the test box;

[0033] a temperature detection module, connected with the test box, for measuring the internal temperature of the test box;

[0034] a control module, connected with the heating module and the cooling module respectively, for controlling the working states of the heating module and the cooling module according to the preset target temperature and the internal temperature, so as to regulate the internal temperature of the test box.

[0035] In a second aspect, the present application provides a thermal aging test system, which comprises an insulation sample and the thermal aging test device according to any one of the above embodiments.

[0036] The thermal aging test device and system comprise a test box, a temperature control assembly and a measurement and control assembly. The insulation sample can be placed in the test box. The temperature control assembly is connected with the test box, and can regulate the internal temperature of the test box in real time, so as to control the thermal stress of different degrees applied to the insulation sample. The measurement and control assembly is partially located in the test box and partially located outside the test box. The measurement and control assembly comprises at least two measurement modules and a selection module. The selection module is connected with each measurement module and the insulation sample. The selection module is used for selecting a path between the measurement module and the insulation sample. The measurement module is used for measuring the dielectric property parameters of the insulation sample under the internal temperature in the case of electrical connection with the insulation sample. The dielectric property parameters measured by each measurement module are different. By selecting different paths between the measurement module and the insulation sample through the selection module, the simultaneous measurement of different dielectric property parameters of the insulation sample can be realized. Therefore, the thermal aging test device of the present application can accurately reflect the operating conditions of the cable insulation material. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0038] Figure 1 FIG. 1 is a structural schematic diagram of a thermal aging test device in an embodiment;

[0039] Figure 2 FIG. 2 is a structural schematic diagram of a thermal aging test device in another embodiment;

[0040] Figure 3 FIG. 3 is a structural schematic diagram of a thermal aging test device in another embodiment;

[0041] Figure 4 Structure diagram of the electric conductivity measurement module in one embodiment;

[0042] Figure 5 Structure diagram of the space charge measurement module in one embodiment;

[0043] Figure 6 Structure diagram of the dielectric loss measurement module in one embodiment;

[0044] Figure 7 Structure diagram of the heat aging test device in another embodiment;

[0045] Figure 8 Structure diagram of the heat aging test device in another embodiment.

[0046] Legend: 1- test box, 2- temperature control assembly, 21- heating module, 22- cooling module, 23- temperature detection module, 24- control module, 3- measurement and control assembly, 31- electric conductivity measurement module, 311- first pressure electrode, 312- first measurement electrode, 313- first DC power supply, 314- first measurement unit, 315- guard electrode, 32- space charge measurement module, 321- second pressure electrode, 322- second measurement electrode, 323- power supply unit, 3231- second DC power supply, 3232- pulse power supply, 324- second measurement unit, 33- dielectric loss measurement module, 331- AC power supply, 332- first bridge arm, 333- second bridge arm, 334- third measurement unit, 34- selection module, 4- insulation sample, 5- insulation shielding assembly. DETAILED DESCRIPTION

[0047] For the purpose of promoting the understanding of the present application, the present application will be more fully described by reference to the following drawings. The embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It should be noted that the embodiments of the present application are not intended to limit the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0049] It should be understood that the terms "first", "second" and so on used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

[0050] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is inverted, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The devices can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatial description terminology will be interpreted accordingly.

[0051] It is noted that when an element is referred to as being "connected", it can be directly connected to the other element or electrically connected via an intervening element. Also, "connected" in the following embodiments, if there is a transmission of electrical signals or data between the connected objects, should be understood as "electrically connected", "communicatively connected", etc.

[0052] As used herein, the singular forms "a", "an" and "the" can include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0053] In the related art, the method for testing the long-term thermal aging of power cable insulation material is generally to place the insulation material in a certain temperature oven for several hours to achieve the thermal aging of the insulation material under different conditions. However, the conventional test device cannot monitor the real-time state of the insulation material, and can only obtain discrete insulation material trends over time by taking out the test sample at specific intervals and testing various methods.

[0054] In addition, space charge, polarization depolarization current, dielectric loss and dielectric parameters are three important parameters of dielectric performance. In the microstructure of dielectric, the three have obvious correlation. For example: the trapping and detrapping process of space charge will produce current, which will affect the measured external current. At the same time, the dielectric loss and the dielectric parameters are also related to the polarization component of the external current. If the polarization component increases, the dielectric loss and the dielectric constant will also increase accordingly. At the same time, the accumulation of space charge is related to the trap distribution in the dielectric, and the conduction current can reflect the trap distribution in the dielectric. In summary, the three dielectric performance tests can reflect the insulation performance of the dielectric, and the results of different tests are related to each other. The combined measurement results can further reflect and characterize the insulation performance of the dielectric.

[0055] However, in the detection device in the related art, space charge, conduction current and dielectric loss are tested separately. That is, they cannot be jointly measured at the same time, and the insulation performance inside the dielectric cannot be better characterized.

[0056] Based on the above technical problems, the present application provides a heat aging test device, which allows the tester to monitor and measure the three parameters in real time during the aging process, and obtains the accurate performance parameters of the insulation material through the joint evaluation and analysis of different parameters.

[0057] In one embodiment, referring to Figure 1 The present application provides a heat aging test device, which comprises a test box 1, a temperature control assembly 2 and a measurement and control assembly 3.

[0058] The test box 1 is used to accommodate the insulation sample 4. The temperature control assembly 2 is connected with the test box 1 and is used to regulate the internal temperature of the test box 1. The measurement and control assembly 3 is partially located in the test box 1 and partially located outside the test box 1. The measurement and control assembly 3 comprises at least two measurement modules and a selection module. The selection module is connected with each measurement module and the insulation sample 4, and is used to select the path between the measurement module and the insulation sample 4. The measurement module is used to measure the dielectric performance parameters of the insulation sample 4 at the internal temperature under the condition of electrical connection with the insulation sample 4. Each measurement module measures different dielectric performance parameters.

[0059] In the application, when the insulating sample 4 is tested, the insulating sample 4 is first placed in the test box 1, and the technician can control the internal temperature of the test box 1 through the temperature control assembly 2 to apply thermal stress to the insulating sample 4. In an example, the technician can control the internal temperature of the test box 1 in real time through the temperature control assembly 2, or the temperature control assembly 2 can control the internal temperature of the test box 1 to change over time according to a preset temperature sequence to simulate the thermal stress that the power cable bears in the actual working process, because the temperature of the power cable is usually higher when the load is higher during the day and lower when the load is lower at night.

[0060] After the thermal stress is applied to the insulating sample 4, the technician can control the switch state of the selection module according to the specific dielectric property parameter to be detected to turn on the corresponding test path. In the case that the test module is electrically connected to the insulating sample 4, the test module can apply electrical stress to the insulating sample 4 and detect the dielectric property parameter of the insulating sample 4 under electrical stress and thermal stress. In the application, the number of measurement modules is multiple, and the dielectric property parameters measured by each measurement module are different. In the application, the selection module can simultaneously turn on the test paths between each measurement module and the insulating sample 4 to simultaneously measure multiple dielectric property parameters.

[0061] The thermal aging test device described above includes a test box, a temperature control assembly, and a measurement and control assembly. The insulating sample can be placed in the test box. The temperature control assembly is connected to the test box and can control the internal temperature of the test box in real time to control the thermal stress applied to the insulating sample at different levels. The measurement and control assembly is partially located in the test box and partially located outside the test box. The measurement and control assembly includes at least two measurement modules and a selection module. The selection module is connected to each measurement module and the insulating sample. The selection module is used to select and turn on the paths between the measurement modules and the insulating sample. The measurement modules are used to measure the dielectric property parameters of the insulating sample at the internal temperature in the case that the measurement modules are electrically connected to the insulating sample. Each measurement module measures different dielectric property parameters. Different paths between the measurement modules and the insulating sample are turned on through the selection module to simultaneously measure different dielectric property parameters of the insulating sample. Therefore, the thermal aging test device of the application can accurately reflect the operating conditions of the cable insulating material.

[0062] In an embodiment, referring to Figure 2 The measurement and control assembly 3 includes at least two of the conductance measurement module 31, the space charge measurement module 32, and the dielectric loss measurement module 33. The conductance measurement module 31 is used to determine the conductance parameter of the insulating sample 4 at the internal temperature in the case that the conductance measurement module 31 is electrically connected to the insulating sample 4. The space charge measurement module 32 is used to determine the space charge parameter of the insulating sample 4 at the internal temperature in the case that the space charge measurement module 32 is electrically connected to the insulating sample 4. The dielectric loss measurement module 33 is used to determine the dielectric loss parameter of the insulating sample 4 at the internal temperature in the case that the dielectric loss measurement module 33 is electrically connected to the insulating sample 4.

[0063] In the application, since the space charge, conductive current and dielectric loss are three important parameters of dielectric properties of insulating materials, the combined measurement results can further reflect and characterize the dielectric insulation performance of the insulating materials compared with the single measurement results. Therefore, the measurement and control assembly 3 in the application includes at least two of the conductive measurement module 31, the space charge measurement module 32 and the dielectric loss measurement module 33. The conductive measurement module 31, the space charge measurement module 32 and the dielectric loss measurement module 33 are respectively connected with the insulating sample 4 through the selection module 34. The technician can select at least two of the dielectric performance parameters such as the space charge, the conductive current and the dielectric loss of the insulating sample 4 according to the needs.

[0064] In one embodiment, referring to Figure 3 , the thermal aging test device further includes an insulation shielding assembly 5.

[0065] The insulation shielding assembly 5 is connected with the insulating sample 4, and the extension direction of the insulation shielding assembly 5 is different from that of the insulating sample 4. The conductive measurement module 31 and the space charge measurement module 32 are located on the first side of the insulation shielding assembly 5, and the dielectric loss measurement module 33 is located on the second side of the insulation shielding assembly 5. The first side and the second side of the insulation shielding assembly 5 are opposite sides in the extension direction of the insulating sample 4. The insulation shielding assembly 5 is used to shield the signal interference between the conductive measurement module 31 and the space charge measurement module 32 and the dielectric loss measurement module 33.

[0066] In the application, since the conductive measurement module 31 and the space charge measurement module 32 are both high-voltage direct-current measurement systems, and the dielectric loss measurement module 33 is a high-voltage alternating-current measurement system, the insulation shielding assembly 5 is connected with the insulating sample 4, and the conductive measurement module 31 and the space charge measurement module 32 are located on the first side of the insulation shielding assembly 5, and the dielectric loss measurement module 33 is located on the second side of the insulation shielding assembly 5. The insulation shielding assembly 5 prevents the coupling between signals of different systems.

[0067] In one embodiment, referring to Figure 4 , the conductive measurement module 31 includes a first pressure electrode 311, a first measurement electrode 312, a first direct-current power supply 313 and a first measurement unit 314.

[0068] The first pressurized electrode 311 is connected with one side of the insulating sample 4 and the first end of the selection module 34 respectively, and the other side of the insulating sample 4 is grounded through the first measuring electrode 312. The first end of the first direct current power supply 313 is connected with the second end of the selection module 34, and the second end of the first direct current power supply 313 is grounded, and the first direct current power supply 313 is used for providing a direct current stabilized voltage signal. The first measuring unit 314 is connected with the first measuring electrode 312, and is used for determining the conductance parameter of the insulating sample 4 at the internal temperature by measuring the current information of the insulating sample 4 when the selection module 34 turns on the first direct current power supply 313 and the first pressurized electrode 311.

[0069] It can be understood that the selection module 34 can include the first switch S1, and the first switch S1 is connected with the first direct current power supply 313 and the first pressurized electrode 311 respectively. The first pressurized electrode 311 and the first measuring electrode 312 are arranged on the opposite sides of the insulating sample 4 respectively, and when the first switch S1 is turned on, the first direct current power supply 313 can provide the direct current stabilized voltage signal to the insulating sample 4 through the first pressurized electrode 311, and a current path can be formed between the first pressurized electrode 311 and the first measuring electrode 312, so that the electric stress can be applied to the insulating sample 4. The PA ammeter can be included in the first measuring unit 314, and the PA ammeter is connected with the first measuring electrode 312 to measure the current flowing through the insulating sample 4, so that the first measuring unit 314 can determine the conductance parameter of the insulating sample 4 at the internal temperature according to the current flowing through the insulating sample 4. The minimum range of the PA ammeter can reach 10 -14 A, and the first direct current power supply 313 can be a program-controlled direct current power supply, and the first direct current power supply 313 can output a voltage in the range of 1kV~10kV according to the requirement.

[0070] In the application, the conductance measurement module 31 can further include at least one protection electrode 315, one end of the protection electrode 315 is connected with the insulating sample 4, the other end is grounded, and the protection electrode 315 is located on the same side as the first pressurized electrode 311. The protection electrode 315 can protect the conductance measurement module 31. In addition, if the surface insulation performance of the insulating sample 4 is poor, the current may flow through the surface of the insulating sample 4 during the test, and at this time, the current measured by the PA ammeter cannot accurately reflect the conductance in the body of the insulating sample 4. In the case of connecting the protection electrode 315, the surface current of the insulating sample 4 will be directly introduced into the ground, which greatly increases the measurement reliability. The first pressurized electrode 311, the first measuring electrode 312 and the protection electrode 315 are located in the test box 1, and the selection module 34, the first direct current power supply 313 and the first measuring unit 314 are located outside the test box 1.

[0071] In one embodiment, please refer to Figure 5The space charge measuring module 32 comprises a second voltage electrode 321, a second measuring electrode 322, a power supply unit 323 and a second measuring unit 324.

[0072] The second voltage electrode 321 is connected with one side of the insulation sample 4 and the third end of the selection module 34 respectively. The other side of the insulation sample 4 is grounded through the second measuring electrode 322. The power supply unit 323 comprises a second direct current power supply 3231 and a pulse power supply 3232. The first end of the second direct current power supply 3231 and the first end of the pulse power supply 3232 are connected with the fourth end of the selection module 34 respectively. The second end of the second direct current power supply 3231 and the second end of the pulse power supply 3232 are grounded respectively. The second direct current power supply 3231 is used to provide a direct current signal. The pulse power supply 3232 is used to provide a pulse signal. The second measuring unit 324 is connected with the second measuring electrode 322. When the second direct current power supply 3231 and the pulse power supply 3232 are turned on by the selection module 34 respectively, the second voltage electrode 321 is used to provide the direct current signal and the pulse signal to the insulation sample 4. The space charge parameters of the insulation sample 4 at the internal temperature are determined by measuring the acoustic pulse signals generated by the insulation sample 4 under the joint action of the direct current signal and the pulse signal.

[0073] In the embodiment, the selection module 34 can further comprise a second switch S2. One end of the second switch S2 is connected with the power supply unit 323. The other end of the second switch S2 is connected with the second voltage electrode 321. When the second switch is turned on, the second direct current power supply 3231 and the pulse power supply 3232 can provide the direct current signal and the pulse signal to the insulation sample 4 through the second voltage electrode 321 respectively. The current path can be formed between the first voltage electrode 311 and the first measuring electrode 312. The electric stress can be applied to the insulation sample 4. The space charge and the electrode interface in the insulation sample 4 can be affected by the pulse electric field force to generate the acoustic pulse signals correspondingly. The piezoelectric electroacoustic pulse sensor can be included in the second measuring unit 324. The piezoelectric electroacoustic pulse sensor can receive the acoustic pulse signals. The space charge parameters of the insulation sample 4 can be obtained by the second measuring unit 324 according to the acoustic pulse signals. The space charge measuring module 32 can further comprise a protection resistor R1 and an isolation capacitor C1. The first end of the second direct current power supply 3231 is connected with the fourth end of the selection module 34 through the protection resistor R1. The first end of the pulse power supply 3232 is connected with the fourth end of the selection module 34 through the isolation capacitor C1. The second voltage electrode 321 and the second measuring electrode 322 are located in the test box 1. The selection module 34, the power supply unit 323 and the second measuring unit 324 are located outside the test box 1.

[0074] In one example, when the measurement and control assembly 3 simultaneously includes the electrical conductivity measurement module 31 and the space charge measurement module 32, the first pressurizing electrode 311 can be multiplexed as the second pressurizing electrode 321, the first measurement electrode 312 can be multiplexed as the second measurement electrode 322, and the first direct current power supply 313 can be multiplexed as the second direct current power supply 3231.

[0075] In one embodiment, referring to Figure 6 The dielectric loss measurement module 33 includes an alternating current power supply 331, a first bridge arm 332, a second bridge arm 333, and a third measurement unit 334. The first end of the alternating current power supply 331 is connected to the midpoint of the second bridge arm 333. The selection module 34 is connected to the second end of the alternating current power supply 331 and the midpoint of the first bridge arm 332, respectively. The first bridge arm 332, the second bridge arm 333, and the third measurement unit 334 are connected in parallel to each other. The first bridge arm 332 includes the insulating sample 4 and a constant capacitor connected in series. The connection point between the insulating sample 4 and the constant capacitor C2 is the midpoint of the first bridge arm 332. The second bridge arm 333 includes an adjustable resistor R2 and an equivalent unit connected in series. The equivalent unit includes a constant resistor R3 and an adjustable capacitor C3 connected in parallel. The connection point between the adjustable resistor R2 and the equivalent unit is the midpoint of the second bridge arm 333. The alternating current power supply 331 is used to provide a pulse signal. The third measurement unit 334 is used to determine the dielectric loss parameter of the insulating sample 4 according to the capacitance value of the adjustable capacitor and the resistance value of the constant resistor when the selection module 34 turns on the alternating current power supply 331 and the voltage at both ends of the first bridge arm 332 and the second bridge arm 333 is equal.

[0076] In application, the selection module 34 can further include a third switch S3, and the third measurement unit 334 can include an alternating current galvanometer. When the third switch S3 is turned on, the alternating current power supply 331 can apply an alternating voltage to the first bridge arm 332 and the second bridge arm 333. Under the action of the alternating voltage, by adjusting the sizes of the adjustable resistor R2 and the adjustable capacitor C3, the first bridge arm 332 and the second bridge arm 333 can reach balance, that is, the current through the alternating current galvanometer is 0. The third measurement unit 334 can calculate the dielectric loss parameter of the insulating sample 4. Specifically: tan δ = ωC3R3, where ω is the angular frequency of the alternating voltage, and δ is the dielectric loss angle, that is, the dielectric loss parameter.

[0077] The test box 1 can further include a high-temperature insulation pipe. The connection lines of the selection module 34, the electrical conductivity measurement module 31, the space charge measurement module 32, and the dielectric loss measurement module 33 with the insulating sample 4 are arranged in the high-temperature insulation pipe, avoiding the deterioration of the connection lines caused by high temperature, and further affecting the test results.

[0078] In one embodiment, referring to Figure 7The temperature control assembly 2 comprises a heating module 21, a cooling module 22, a temperature detection module 23 and a control module 24.

[0079] The heating module 21 is connected with the test box 1 and is used for generating heat; the cooling module 22 is connected with the test box 1 and is used for transmitting cooling matter to the test box 1; the temperature detection module 23 is connected with the test box 1 and is used for measuring the internal temperature of the test box 1; and the control module 24 is connected with the heating module 21 and the cooling module 22 respectively and is used for controlling the working states of the heating module 21 and the cooling module 22 according to the preset target temperature and the internal temperature, so as to regulate the internal temperature of the test box 1.

[0080] Specifically, the cooling module 22 can be an air cooling module, the test box 1 can be provided with an air inlet and an air outlet, the cooling module 22 can send cooling air into the test box 1 through the air inlet, and the cooling air can be discharged from the test box 1 through the air outlet. The heating module 21 can include a resistance wire, the control module 24 can receive the temperature information detected by the temperature detection module 23, and the working states of the heating module 21 and the cooling module 22 can be controlled according to the preset target temperature and the actual temperature information, so as to regulate the internal temperature of the test box 1.

[0081] In a detailed embodiment, please refer to Figure 8 The measurement and control assembly 3 comprises an electric conductance measurement module 31, a space charge measurement module 32 and a dielectric loss measurement module 33. The first pressurizing electrode 311 can be reused as the second pressurizing electrode 321, the first measurement electrode 312 can be reused as the second measurement electrode 322, the first direct current power supply 313 can be reused as the second direct current power supply 3231, the first measurement unit 314 can include a low-pass filter and a PA ammeter, the PA ammeter is connected with the first measurement electrode 312 through the low-pass filter, and the low-pass filter is used for filtering the pulse signal in the space charge measurement module 32, so that the first measurement unit 314 only measures the electric conductance current caused by the direct current voltage. In addition, two protection electrodes 315 can also be installed near the insulating shielding assembly 5 of the insulating sample 4, so as to remove the surface current caused by high voltage and prevent mutual interference between different measurement modules.

[0082] The internal temperature of the test box 1 is cooperatively regulated by the heating module 21 and the cooling module 22, and the switching states of the control switches S1-S3 can be controlled, so that the electric conductance parameters, the space charge parameters and the dielectric loss parameters of the insulating sample 4 under the internal temperature can be selectively measured. In summary, the thermal aging test device of the present application can simulate the thermal stress condition of the power cable in the actual working process and simultaneously measure multiple dielectric performance parameters, so as to accurately reflect the operation condition of the cable insulating material.

[0083] In one embodiment, the present application provides a heat aging test system, the heat aging test system comprising an insulation sample and the heat aging test device of any of the above embodiments.

[0084] In the description of the present specification, the description referring to the terms "some embodiments", "other embodiments", "ideal embodiments", and the like means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0085] The technical features of the above embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present specification.

[0086] The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the present application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A heat aging test device characterized by comprising: The heat aging test device comprises: a test box for accommodating an insulation sample; a temperature control assembly connected with the test box for regulating the internal temperature of the test box; a measurement and control assembly, part of which is located in the test box and the rest is located outside the test box, the measurement and control assembly comprising at least two measurement modules and a selection module, the selection module being connected with each of the measurement modules and the insulation sample, the selection module being used for selecting to turn on the passage between the measurement modules and the insulation sample; the measurement modules being used for measuring the dielectric performance parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample; wherein the dielectric performance parameters measured by each of the measurement modules are different; the measurement and control assembly comprising at least two of a conductance measurement module, a space charge measurement module and a dielectric loss measurement module; wherein the conductance measurement module is used for determining the conductance parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample; the space charge measurement module is used for determining the space charge parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample; and the dielectric loss measurement module is used for determining the dielectric loss parameters of the insulation sample at the internal temperature under the condition of electrical connection with the insulation sample; the device further comprising an insulation shielding assembly connected with the insulation sample, the insulation shielding assembly being different from the extension direction of the insulation sample, the conductance measurement module and the space charge measurement module being located on a first side of the insulation shielding assembly, the dielectric loss measurement module being located on a second side of the insulation shielding assembly, the first side and the second side of the insulation shielding assembly being opposite sides in the extension direction of the insulation sample, the insulation shielding assembly being used for shielding the signal interference between the conductance measurement module and the space charge measurement module and the dielectric loss measurement module.

2. The heat aging test apparatus according to claim 1, characterized by the conductance measurement module comprising: a first pressure electrode connected with one side of the insulation sample and a first end of the selection module respectively; a first measurement electrode, the other side of the insulation sample being grounded through the first measurement electrode; a first direct current power supply, a first end of the first direct current power supply being connected with a second end of the selection module, a second end of the first direct current power supply being grounded, the first direct current power supply being used for providing a direct current stabilized voltage signal; a first measurement unit connected with the first measurement electrode, used for determining the conductance parameters of the insulation sample at the internal temperature by measuring the current information of the insulation sample under the condition that the selection module turns on the first direct current power supply and the first pressure electrode.

3. The heat aging test apparatus according to claim 1, characterized by the space charge measurement module comprising: a second pressure electrode connected with one side of the insulation sample and a third end of the selection module respectively; a second measurement electrode, the other side of the insulation sample being grounded through the second measurement electrode; a second direct current power supply, a first end of the second direct current power supply being connected with a fourth end of the selection module, a second end of the second direct current power supply being grounded, the second direct current power supply being used for providing a direct current stabilized voltage signal; a second measurement unit connected with the second measurement electrode, used for determining the space charge parameters of the insulation sample at the internal temperature by measuring the current information of the insulation sample under the condition that the selection module turns on the second direct current power supply and the second pressure electrode. The power supply unit comprises a second direct current power supply and a pulse power supply, a first end of the second direct current power supply and a first end of the pulse power supply are connected with a fourth end of the selection module respectively, a second end of the second direct current power supply and a second end of the pulse power supply are grounded respectively, the second direct current power supply is used for providing a direct current signal, and the pulse power supply is used for providing a pulse signal. The second measurement unit is connected with the second measurement electrode, and is used for determining a space charge parameter of the insulating sample at the internal temperature by measuring an acoustic pulse signal generated by the insulating sample under the joint action of the direct current signal and the pulse signal in the case that the second direct current power supply and the pulse power supply are turned on by the selection module and are connected with the second pressure electrode respectively.

4. The heat aging test apparatus according to claim 3, characterized by The space charge measurement module further comprises: A protection resistor, and the first end of the second direct current power supply is connected with the fourth end of the selection module through the protection resistor. An isolation capacitor, and the first end of the pulse power supply is connected with the fourth end of the selection module through the isolation capacitor.

5. The heat aging test apparatus according to claim 1, characterized by The dielectric loss measurement module comprises an alternating current power supply, a first bridge arm, a second bridge arm and a third measurement unit, a first end of the alternating current power supply is connected with a midpoint of the second bridge arm, the selection module is connected with a second end of the alternating current power supply and a midpoint of the first bridge arm respectively, the first bridge arm, the second bridge arm and the third measurement unit are connected with each other in parallel, the first bridge arm comprises the insulating sample and a constant value capacitor connected in series, a connection point between the insulating sample and the constant value capacitor is the midpoint of the first bridge arm, the second bridge arm comprises an adjustable resistor and an equivalent unit connected in series, the equivalent unit comprises a constant value resistor and an adjustable capacitor connected in parallel, a connection point between the adjustable resistor and the equivalent unit is a midpoint of the second bridge arm, the alternating current power supply is used for providing a pulse signal, and the third measurement unit is used for determining a dielectric loss parameter of the insulating sample according to a capacitance value of the adjustable capacitor and a resistance value of the constant value resistor in the case that the alternating current power supply is turned on by the selection module and is connected with the midpoint of the first bridge arm, and voltages at two ends of the first bridge arm and the second bridge arm are equal.

6. The heat aging test apparatus according to any one of claims 1 to 5, characterized by The thermal aging test device further comprises at least one protection electrode, and the insulating sample is grounded through the protection electrode.

7. The heat aging test apparatus according to any one of claims 1 to 5, characterized by The temperature control assembly comprises: A heating module connected with the test box and used for generating heat; A cooling module connected with the test box and used for transmitting a cooling object to the test box; A temperature detection module connected with the test box and used for measuring an internal temperature of the test box; A control module connected with the heating module and the cooling module respectively and used for controlling working states of the heating module and the cooling module according to a preset target temperature and the internal temperature, so as to regulate and control the internal temperature of the test box.

8. A heat aging test system, characterized by, The system comprises an insulating sample and the thermal aging test device according to any one of claims 1 to 7.

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