High-temperature electro-acoustic pulse method space charge measuring device and method

Abstract

The invention relates to the technical field of space charge measurement, and discloses a high-temperature electro-acoustic pulse method space charge measurement device and method, and the device comprises a measurement unit, an upper electrode unit, and a lower electrode unit. The measuring unit comprises a wiring device and a signal acquisition device; the upper electrode unit comprises an upper electrode, a first shell arranged on the upper electrode in a sleeving mode and a heating device arranged in the first shell. The wiring device is electrically connected with the upper electrode; the lower electrode unit comprises a lower electrode, and the lower portion of the lower electrode is connected with the signal collecting device. The upper electrode and the lower electrode can heat the upper surface and the lower surface of a sample at the same time, so that the sample is rapidly heated; and a water cooling device is arranged below the lower electrode to ensure that the piezoelectric sensor works at a safe working temperature. When the device for measuring the electroacoustic pulse space charge at the high temperature is used for measuring the characteristics of the space charge at the high temperature, a sample can be uniformly heated and rapidly heated to a set temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of space charge measurement, and in particular to a high-temperature electroacoustic pulse space charge measurement device and method. Background Art

[0002] With the rapid development of the modern electric power industry, power electronic devices are also developing towards high voltage and high power. Silicon carbide devices are widely used in DC transmission due to their faster switching speed, higher frequency and higher voltage tolerance. The application of silicon carbide devices also means that packaging materials need to withstand higher temperatures and greater voltages. High electric fields and high temperatures can easily lead to the accumulation of space charge inside the material, and space charge is considered to be one of the important reasons that affect electric field distortion and reduce insulation reliability. Understanding the space charge characteristics of materials at high temperatures can provide guidance for evaluating electric field distortion and improving device packaging insulation reliability.

[0003] In the prior art, to study the spatial charge distribution in solid dielectrics, the first thing to do is to measure the spatial charge distribution. The electroacoustic pulse method (PEA method) spatial charge measurement technology is one of the most widely used measurement methods at home and abroad. The prior art solution is implemented by the electroacoustic pulse method spatial charge measurement system. It mainly includes an electrode system, a nanosecond pulse generator, a high-voltage DC generator, an oscilloscope, a heating\water-cooling constant temperature system and a computer. During the measurement, the sheet sample is first clamped between the upper and lower measuring electrodes. Under the pressurized state, the nanosecond pulse voltage acts on the sample. The charge in the sample causes electrostatic force under the action of the pulse electric field, generating pressure waves. The pressure wave then passes through the sample and the lower electrode, is detected by the piezoelectric sensor and converts the acoustic signal into an electrical signal, and then amplified by the amplifier, observed by the oscilloscope to obtain real-time data and collected and saved by the computer, and then the waveform is restored and analyzed.

[0004] Existing charge measurement devices are unable to stably provide materials with high temperatures exceeding 150°C and measure the spatial charge characteristics of materials at high temperatures. They cannot be used to study the spatial charge characteristics of high-power power electronic device packaging materials under high-temperature working environments. Summary of the invention

[0005] The present invention aims to at least solve the technical problem that the existing charge measurement device cannot provide a stable high temperature for the material, cannot measure the space charge characteristics of the material at high temperature, and cannot be used to study the space charge characteristics of high-power power electronic device packaging materials under high temperature working environment.

[0006] To this end, an object of the present invention is to provide a high temperature electroacoustic pulse method space charge measurement device, comprising a measurement unit, an upper electrode unit and a lower electrode unit;

[0007] The measuring unit includes a wiring device and a signal acquisition device;

[0008] The upper electrode unit comprises an upper electrode, a first shell sleeved on the upper electrode, and a heating device arranged inside the first shell; the wiring device is electrically connected to the upper electrode;

[0009] The lower electrode unit comprises a lower electrode, and the lower part of the lower electrode is connected to the signal acquisition device.

[0010] The lower electrode unit also includes a heating plate connected below the lower electrode;

[0011] A circulation groove is provided between the heating plate and the lower electrode for heating and raising the temperature of the lower electrode.

[0012] Furthermore, the circulation groove is an annular structure, and is arranged below the electrode plate of the lower electrode.

[0013] Furthermore, the signal acquisition device is connected to the center of the lower electrode and contacts the tail end of the lower electrode.

[0014] Furthermore, the heating device includes a heating chamber connected to the upper electrode and a heating tube connected to the heating chamber.

[0015] Furthermore, the signal acquisition device includes a piezoelectric sensor and a circulating water channel arranged around the piezoelectric sensor, and the circulating water channel is used for heat dissipation of the piezoelectric sensor.

[0016] Furthermore, the signal acquisition device includes an amplifier connected to the piezoelectric sensor and a shielding box arranged outside the amplifier.

[0017] Furthermore, the upper electrode unit includes a first insulating sleeve sleeved on the upper electrode and a locking column threadedly connected to the first insulating sleeve, and the locking column is arranged above the first shell.

[0018] Furthermore, the wiring device includes a second shell, a capacitor connected to the upper electrode, and a high-voltage line interface and a BNC connector arranged on the second shell.

[0019] Furthermore, the upper electrode, the lower electrode and the second shell are all made of aluminum alloy.

[0020] The present invention provides a method for measuring space charge using a high temperature electroacoustic pulse method, which is implemented using any of the above-mentioned high temperature electroacoustic pulse method space charge measuring devices, and comprises the following steps:

[0021] Place the test sample on the upper surface of the lower electrode;

[0022] Fixing the first shell above the lower electrode;

[0023] Use the upper electrode to press the sample to be tested;

[0024] Connecting the wiring device to the upper electrode;

[0025] Connecting circulating baths of different temperatures to the heating device and the signal acquisition device respectively, so that the heating device is heated up and the signal acquisition device is cooled down;

[0026] Then, the wiring device is connected to a high voltage DC source and a pulse generator; and the signal acquisition device is connected to an oscilloscope;

[0027] Turn on the circulating bath and the heating plate, turn on the pulse generator, turn on the high-voltage direct current source to the required voltage, and turn on the oscilloscope to collect signals.

[0028] The present invention discloses a high temperature electroacoustic pulse method space charge measurement device and method, which has the following beneficial effects:

[0029] The invention discloses a device for measuring space charge of an electroacoustic pulse at high temperature. An upper electrode and a lower electrode can heat the upper and lower surfaces of a sample at the same time, so that the temperature of the sample rises rapidly. A water cooling device is arranged under the lower electrode to ensure that the piezoelectric sensor works at a safe working temperature. When the device for measuring space charge of an electroacoustic pulse at high temperature is used, the sample can be uniformly heated and quickly heated to a set temperature when measuring space charge characteristics at high temperature.

[0030] The first shell of the upper electrode unit is connected and fixed with the lower electrode through a stud, and then the lock pin of the upper electrode unit is screwed down to press the sample tightly; the shielding box of the lower electrode and the measuring device is separated by a circulating water channel to ensure that the signal acquisition device can collect data at room temperature; the piezoelectric sensor and the amplifier are connected through an SMA interface, and the circulating water channel can be easily removed after the connection between the piezoelectric sensor and the amplifier is disconnected. The assembly and disassembly of the entire experimental device is very convenient.

[0031] A high-temperature heating chamber is provided in the first shell, and a circulation groove is provided between the lower electrode and the heating plate. The lower electrode adopts a hollow circulation groove to control the temperature. As long as the volume of the circulation groove is large enough, the upper and lower electrodes in contact with the upper and lower surfaces of the material to be tested can be quickly heated to the set temperature.

[0032] The circulation tank adopts a circular ring structure and is set under the lower electrode plate. The piezoelectric sensor is placed at the center of the circular ring structure and directly contacts the tail end of the lower electrode. In this way, the piezoelectric sensor directly contacts the lower electrode, so that the signal transmission of the lower electrode will not be affected by the existence of the circulation tank, making the measurement result more accurate. At the same time, if the circulation tank accidentally leaks, the piezoelectric sensor will not be damaged. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 1 This is a structural diagram of a high-temperature electroacoustic pulse method space charge measurement device of the present invention.

[0035] In the figure, the reference numerals are as follows:

[0036] 101. Second shell; 102. Fourth insulating sleeve; 103. Second insulating sleeve; 104. Locking column; 105. BNC connector; 106. Insulating flange; 107. First shell; 108. Third insulating sleeve; 109. First insulating sleeve; 110. Heating tube; 111. Heating chamber; 112. Upper electrode; 113. Lower electrode; 114. Heating plate; 115. Heat sink; 116. Circulating water channel; 117. Piezoelectric sensor; 118. Water channel container; 119. Shielding box; 120. Amplifier; 121. Circulating tank. DETAILED DESCRIPTION

[0037] Various aspects and features of the present invention are described herein with reference to the accompanying drawings.

[0038] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of the embodiments. Other modifications within the scope and spirit of the present invention will occur to those skilled in the art.

[0039] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

[0040] These and other characteristics of the invention will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the accompanying drawings.

[0041] It should also be understood that, although the invention has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the invention that have the characteristics recited in the claims and are therefore within the scope of protection defined thereby.

[0042] The above and other aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0043] Specific embodiments of the present invention are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present invention, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid obscuring the present invention with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present invention in a variety of ways with substantially any suitable detailed structure.

[0044] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0045] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

[0046] Example 1

[0047] like Figure 1 As shown, this embodiment provides a high-temperature electroacoustic pulse method space charge measurement device, including a measurement unit, an upper electrode unit and a lower electrode unit;

[0048] The measuring unit includes a wiring device and a signal acquisition device;

[0049] The upper electrode unit includes an upper electrode 112, a first shell 107 sleeved on the upper electrode 112, and a heating device arranged inside the first shell 107; the wiring device is electrically connected to the upper electrode 112;

[0050] The lower electrode unit includes a lower electrode 113 , and the lower portion of the lower electrode 113 is connected to the signal acquisition device.

[0051] In the present invention, the high-voltage cable and the cable of the high-frequency pulse power supply are connected to the upper electrode 112 through the wiring device; the heating device heats the upper electrode 112, and the temperature inside the first shell 107 rises rapidly, which has an insulating effect on the upper electrode 112, which is beneficial to ensure the constant temperature state of the upper electrode 112, thereby enabling the sample to be evenly heated and quickly heated to the set temperature.

[0052] Example 2

[0053] like Figure 1 As shown, this embodiment provides a high-temperature electroacoustic pulse method space charge measurement device, including a measurement unit, an upper electrode unit and a lower electrode unit;

[0054] The measuring unit includes a wiring device and a signal acquisition device;

[0055] The upper electrode unit includes an upper electrode 112, a first shell 107 sleeved on the upper electrode 112, and a heating device arranged inside the first shell 107; the wiring device is electrically connected to the upper electrode 112;

[0056] The lower electrode unit includes a lower electrode 113 , and the lower portion of the lower electrode 113 is connected to the signal acquisition device.

[0057] In the present invention, the high-voltage cable and the cable of the high-frequency pulse power supply are connected to the upper electrode 112 through the wiring device; the heating device heats the upper electrode 112, and the temperature inside the first shell 107 rises rapidly, which has an insulating effect on the upper electrode 112, which is beneficial to ensure the constant temperature state of the upper electrode 112, thereby enabling the sample to be evenly heated and quickly heated to the set temperature.

[0058] The difference between this embodiment and the first embodiment is that:

[0059] The lower electrode unit further includes a heating plate 114 connected below the lower electrode 113, and the heating plate 114 heats the lower electrode 113 to increase the temperature of the sample above the lower electrode 113;

[0060] Specifically, the heating plate 114 is disposed below the lower electrode 113 .

[0061] Specifically, a circulation groove 121 is provided between the heating plate 114 and the lower electrode 113 for heating the lower electrode 113 .

[0062] More specifically, the circulation groove 121 is an annular structure, which is arranged under the electrode plate of the lower electrode 113; the signal acquisition device is connected at the center of the lower electrode 113 and is in direct contact with the tail end of the lower electrode 113, so that the signal transmission of the lower electrode 113 will not be affected by the existence of the circulation groove 121, so that the measurement result is more accurate; moreover, if the circulation groove 121 accidentally leaks, the signal acquisition device will not be damaged.

[0063] The present invention provides a high-temperature electroacoustic pulse method space charge measurement device. By providing a heating device for the upper electrode 112 and a heating plate for the lower electrode 113, the upper and lower surfaces of the sample can be heated simultaneously, thereby improving work efficiency.

[0064] Example 3

[0065] like Figure 1 As shown, this embodiment provides a high-temperature electroacoustic pulse method space charge measurement device, including a measurement unit, an upper electrode unit and a lower electrode unit;

[0066] The measuring unit includes a wiring device and a signal acquisition device;

[0067] The upper electrode unit includes an upper electrode 112, a first shell 107 sleeved on the upper electrode 112, and a heating device arranged inside the first shell 107; the wiring device is electrically connected to the upper electrode 112;

[0068] The lower electrode unit includes a lower electrode 113 , and the lower portion of the lower electrode 113 is connected to the signal acquisition device.

[0069] In the present invention, the high-voltage cable and the cable of the high-frequency pulse power supply are connected to the upper electrode 112 through the wiring device; the heating device heats the upper electrode 112, and the temperature inside the first shell 107 rises rapidly, which has an insulating effect on the upper electrode 112, which is beneficial to ensure the constant temperature state of the upper electrode 112, thereby enabling the sample to be evenly heated and quickly heated to the set temperature.

[0070] The difference between this embodiment and the first embodiment is that:

[0071] The heating device includes a heating chamber 111 connected to the upper electrode 112 and a heating tube 110 connected to the heating chamber 111 .

[0072] Specifically, the heating chamber 111 is connected to the upper electrode 112 through an insulating sleeve.

[0073] Specifically, openings are provided on both sides of the first shell, and a third insulating sleeve 108 is provided at the opening. One end of the heating tube 110 passes through the third insulating sleeve 108 and is connected to a heat source. The heating tube 108 is a hose, and the heating medium is silicone oil.

[0074] Specifically, the heating tube 110 is connected to a high-temperature constant-temperature circulating bath. When in use, the high-temperature silicone oil in the high-temperature circulating bath enters the heating chamber 111 through one end of the heating tube 110, forms a circulation flow in the heating chamber 111, and returns to the high-temperature circulating bath through another heating tube 110, so that the heating chamber 111 is always maintained at a set temperature, thereby providing a high-temperature environment for the upper electrode 112.

[0075] Example 4

[0076] like Figure 1 As shown, this embodiment provides a high-temperature electroacoustic pulse method space charge measurement device, including a measurement unit, an upper electrode unit and a lower electrode unit;

[0077] The measuring unit includes a wiring device and a signal acquisition device;

[0078] The upper electrode unit includes an upper electrode 112, a first shell 107 sleeved on the upper electrode 112, and a heating device arranged inside the first shell 107; the wiring device is electrically connected to the upper electrode 112;

[0079] The lower electrode unit includes a lower electrode 113 , and the lower portion of the lower electrode 113 is connected to the signal acquisition device.

[0080] In the present invention, the high-voltage cable and the cable of the high-frequency pulse power supply are connected to the upper electrode 112 through the wiring device; the heating device heats the upper electrode 112, and the temperature inside the first shell 107 rises rapidly, which has an insulating effect on the upper electrode 112, which is beneficial to ensure the constant temperature state of the upper electrode 112, thereby enabling the sample to be evenly heated and quickly heated to the set temperature.

[0081] The difference between this embodiment and the first embodiment is that:

[0082] The signal acquisition device includes a piezoelectric sensor 117 and a circulating water channel 116 arranged around the piezoelectric sensor 117 , and the circulating water channel 116 is used for heat dissipation of the piezoelectric sensor 117 .

[0083] Specifically, the signal acquisition device further includes a water channel container 118, and the circulating water channel 116 is disposed in the water channel container 118.

[0084] The signal acquisition device includes an amplifier 120 connected to the piezoelectric sensor 117 and a shielding box arranged outside the amplifier 120 .

[0085] The piezoelectric sensor 117 is installed at the bottom of the lower electrode 113. Although the lower electrode 113 is relatively thick, it is made of aluminum alloy, and the acoustic wave attenuation coefficient of aluminum alloy is small, so the loss of signal acquisition accuracy is very small.

[0086] The side of the piezoelectric sensor 117 is coated with thermal conductive silicone to strengthen the contact with the circulating water channel 116. The present invention relies on gravity to make the piezoelectric sensor 117 press the circulating water channel 116, ensuring sufficient forced water cooling and heat dissipation effect, so that the temperature in the shielding box 119 of the signal acquisition device is close to the room temperature, avoiding negative impact on signal acquisition.

[0087] Example 5

[0088] like Figure 1 As shown, this embodiment provides a high-temperature electroacoustic pulse method space charge measurement device, including a measurement unit, an upper electrode unit and a lower electrode unit;

[0089] The measuring unit includes a wiring device and a signal acquisition device;

[0090] The upper electrode unit includes an upper electrode 112, a first shell 107 sleeved on the upper electrode 112, and a heating device arranged inside the first shell 107; the wiring device is electrically connected to the upper electrode 112;

[0091] The lower electrode unit includes a lower electrode 113 , and the lower portion of the lower electrode 113 is connected to the signal acquisition device.

[0092] In the present invention, the high-voltage cable and the cable of the high-frequency pulse power supply are connected to the upper electrode 112 through the wiring device; the heating device heats the upper electrode 112, and the temperature inside the first shell 107 rises rapidly, which has an insulating effect on the upper electrode 112, which is beneficial to ensure the constant temperature state of the upper electrode 112, thereby enabling the sample to be evenly heated and quickly heated to the set temperature.

[0093] The difference between this embodiment and the first embodiment is that:

[0094] The upper electrode unit includes a first insulating sleeve 109 sleeved on the upper electrode 112 and a locking column 104 threadedly connected to the first insulating sleeve 109 . The locking column 104 is disposed above the first shell 107 .

[0095] Specifically, the locking column 104 is provided with an internal thread, and the first insulating sleeve 109 is provided with an external thread. The locking column 104 is rotated to move the upper electrode 112 downward, thereby pressing the sample.

[0096] The first insulating sleeve 109 is a polytetrafluoroethylene sleeve for achieving insulation.

[0097] An insulating flange 106 is provided at the connection between the upper electrode 112 and the first shell 107 , and the upper electrode 112 passes through the insulating flange 106 .

[0098] The lower electrode 113 is connected to the first shell 107 by screws, which facilitates the assembly and disassembly of the entire device.

[0099] Example 6

[0100] like Figure 1 As shown, this embodiment provides a high-temperature electroacoustic pulse method space charge measurement device, including a measurement unit, an upper electrode unit and a lower electrode unit;

[0101] The measuring unit includes a wiring device and a signal acquisition device;

[0102] The upper electrode unit includes an upper electrode 112, a first shell 107 sleeved on the upper electrode 112, and a heating device arranged inside the first shell 107; the wiring device is electrically connected to the upper electrode 112;

[0103] The lower electrode unit includes a lower electrode 113 , and the lower portion of the lower electrode 113 is connected to the signal acquisition device.

[0104] In the present invention, the high-voltage cable and the cable of the high-frequency pulse power supply are connected to the upper electrode 112 through the wiring device; the heating device heats the upper electrode 112, and the temperature inside the first shell 107 rises rapidly, which has an insulating effect on the upper electrode 112, which is beneficial to ensure the constant temperature state of the upper electrode 112, thereby enabling the sample to be evenly heated and quickly heated to the set temperature.

[0105] The difference between this embodiment and the first embodiment is that:

[0106] The wiring device includes a second housing 101 , a capacitor connected to the upper electrode 112 , and a high-voltage line interface and a BNC connector 105 arranged on the second housing 101 .

[0107] The second housing 101 is disposed on the outside of the lock cylinder 104;

[0108] A fourth insulating sleeve 102 is provided in the high voltage line interface;

[0109] A second insulating sleeve 102 is disposed between the fourth insulating sleeve 102 and the locking column 104 .

[0110] The upper electrode 112 , the lower electrode 113 , and the second shell 101 are all made of aluminum alloy.

[0111] A heat sink 115 is disposed around the lower portion of the lower electrode 113 .

[0112] When the high temperature electroacoustic pulse space charge measuring device of the present invention is used:

[0113] When measuring the space charge test at high temperature, put the sheet sample to be tested in the center of the lower electrode 113, fix the first shell 107 on the top of the lower electrode 113 with studs, and note that the sample should be placed just below the upper electrode 112. Rotate the lock column 104 downward to make the upper electrode 112 press the sample, cover the second shell 101 on the upper electrode 112, and then connect the high-temperature and low-temperature circulating baths to the heating chamber 111 and the lower circulating water channel 116 of the upper electrode unit through rubber tubes respectively; the heating chamber 111 is filled with silicone oil, and the circulating water channel 116 is filled with pure water.

[0114] Then, the high-voltage line interface of the measuring unit is connected to the high-voltage DC source, the pulse generator is connected to the BNC connector of the measuring unit; and the amplifier 120 is connected to the oscilloscope.

[0115] After the connection is completed, turn on the high-temperature and low-temperature circulating baths and the heating plate 114, set the required temperature, so that the upper and lower electrodes can quickly reach the required temperature, while ensuring the normal operation of the piezoelectric sensor 117. Turn on the pulse source, turn on the high-voltage DC source switch and rotate the knob to the required high voltage. Turn on the oscilloscope for signal acquisition.

[0116] If you only need to measure the space charge characteristics of the material at room temperature, turn off the circulating bath and the heating plate. The rest of the operations are the same as those under high temperature conditions.

[0117] The present invention discloses a device for measuring space charge of an electroacoustic pulse at high temperature. The upper electrode 112 and the lower electrode 113 can heat the upper and lower surfaces of a sample at the same time, so that the sample is heated rapidly. A water cooling device is arranged under the lower electrode to ensure that the piezoelectric sensor works at a safe working temperature. When the device for measuring space charge of an electroacoustic pulse at high temperature is used, the sample can be uniformly heated and quickly heated to a set temperature when measuring space charge characteristics at high temperature.

[0118] The first shell 107 of the upper electrode unit is connected and fixed to the lower electrode 113 through a stud, and then the lock column 104 of the upper electrode unit is screwed down to press the sample tightly; the lower electrode 113 and the shielding box 119 of the measuring device are separated by a circulating water channel 116 to ensure that the signal acquisition device can collect data at room temperature; the piezoelectric sensor 117 and the amplifier 120 are connected through an SMA interface, and the circulating water channel 116 can be easily removed after the connection between the piezoelectric sensor 117 and the amplifier 120 is released. The assembly and disassembly of the entire experimental device is very convenient.

[0119] A high-temperature heating chamber is provided in the first shell 107, and a circulation groove 121 is provided between the lower electrode 113 and the heating plate 114. The lower electrode 113 adopts the hollow circulation groove 121 to control the temperature. As long as the volume of the circulation groove 121 is large enough, the upper and lower electrodes in contact with the upper and lower surfaces of the material to be tested can be quickly heated to the set temperature.

[0120] The circulation tank 121 adopts a hollow circle structure and is installed under the lower electrode 113 plate. The piezoelectric sensor 117 is placed at the center of the hollow circle and directly contacts the plate. In this way, the piezoelectric sensor 117 directly contacts the lower electrode 113, so that the signal transmission of the lower electrode 113 is not affected by the existence of the circulation tank 121, making the measurement result more accurate. At the same time, if the circulation tank 121 accidentally leaks, the piezoelectric sensor 117 will not be damaged.

[0121] Example 6

[0122] This embodiment provides a method for measuring space charge using a high temperature electroacoustic pulse method, which is implemented using the high temperature electroacoustic pulse method space charge measuring device described in any of the above embodiments, and includes the following steps:

[0123] The test sample is placed on the upper surface of the lower electrode 113;

[0124] Fixing the first shell above the lower electrode 113;

[0125] Using the upper electrode 112 to compress the sample to be tested;

[0126] Connecting the wiring device to the upper electrode 112;

[0127] Connecting circulating baths of different temperatures to the heating device and the signal acquisition device respectively, so that the heating device is heated up and the signal acquisition device is cooled down;

[0128] Then, the wiring device is connected to a high voltage DC source and a pulse generator; and the signal acquisition device is connected to an oscilloscope;

[0129] The circulating bath and the heating plate 114 are turned on, the pulse generator is turned on, the high voltage DC source is turned on to a required voltage, and the oscilloscope is turned on to collect signals.

[0130] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other to form a technical solution.

[0131] In addition, although each operation is described in a specific order, this should not be understood as requiring these operations to be performed in the specific order shown or in a sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination mode.

[0132] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

[0133] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Claims

1. A high temperature electroacoustic pulse method space charge measurement device, characterized in that: It includes a measuring unit, an upper electrode unit and a lower electrode unit; The measuring unit includes a wiring device and a signal acquisition device; The upper electrode unit comprises an upper electrode, a first shell sleeved on the upper electrode, and a heating device arranged inside the first shell; the wiring device is electrically connected to the upper electrode; The lower electrode unit comprises a lower electrode, and the lower part of the lower electrode is connected to the signal acquisition device; The lower electrode unit also includes a heating plate connected below the lower electrode; A circulation groove is provided between the heating plate and the lower electrode for heating and raising the temperature of the lower electrode.

2. The high temperature electroacoustic pulse method space charge measurement device according to claim 1, characterized in that: The circulation groove is an annular structure and is arranged below the electrode plate of the lower electrode.

3. The high temperature electroacoustic pulse method space charge measurement device according to claim 2, characterized in that: The signal acquisition device is connected to the center of the lower electrode and contacts the tail end of the lower electrode.

4. The high temperature electroacoustic pulse method space charge measurement device according to claim 1, characterized in that: The heating device includes a heating chamber connected to the upper electrode and a heating tube connected to the heating chamber.

5. The high temperature electroacoustic pulse method space charge measurement device according to claim 4, characterized in that: The signal acquisition device includes a piezoelectric sensor and a circulating water channel arranged around the piezoelectric sensor, and the circulating water channel is used for heat dissipation of the piezoelectric sensor.

6. The high temperature electroacoustic pulse method space charge measurement device according to claim 5, characterized in that: The signal acquisition device includes an amplifier connected to the piezoelectric sensor and a shielding box arranged outside the amplifier.

7. The high temperature electroacoustic pulse method space charge measurement device according to claim 1, characterized in that: The upper electrode unit comprises a first insulating sleeve sleeved on the upper electrode and a locking column threadedly connected to the first insulating sleeve, wherein the locking column is arranged above the first shell.

8. The high temperature electroacoustic pulse method space charge measurement device according to claim 1, characterized in that: The wiring device includes a second shell, a capacitor connected to the upper electrode, and a high-voltage line interface and a BNC connector arranged on the second shell.

9. The high temperature electroacoustic pulse method space charge measurement device according to claim 8, characterized in that: The upper electrode, the lower electrode and the second shell are all made of aluminum alloy.

10. A high temperature electroacoustic pulse method for measuring space charge, characterized in that: The method is implemented by using the high temperature electroacoustic pulse method space charge measurement device as described in any one of claims 1 to 9, comprising the following steps: Place the test sample on the upper surface of the lower electrode; Fixing the first shell above the lower electrode; Use the upper electrode to press the sample to be tested; Connecting the wiring device to the upper electrode; Connecting circulating baths of different temperatures to the heating device and the signal acquisition device respectively, so that the heating device is heated up and the signal acquisition device is cooled down; Then, the wiring device is connected to a high voltage DC source and a pulse generator; and the signal acquisition device is connected to an oscilloscope; Turn on the circulating bath and the heating plate, turn on the pulse generator, turn on the high-voltage direct current source to the required voltage, and turn on the oscilloscope to collect signals.

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