Portable direct-current partial discharge current pulse train generation system and equipment detection method thereof

Abstract

The invention relates to a portable direct-current partial discharge current pulse train generation system and an equipment detection method thereof, belongs to the technical field of direct-current partial discharge testing, and solves the problem that a portable direct-current partial discharge current pulse train generation system and a matched equipment detection method are lacked in the prior art. The invention relates to a portable direct-current partial discharge current pulse train generation system. The generation system comprises a central processing unit, a current pulse-time sequence generator and an inductor, wherein the central processing unit is used for loading an algorithm file of an abc equivalent model and constructing a reference direct current TPRPD spectrogram; the current pulse-time sequence generator is used for generating a corresponding transient current pulse train according to the reference direct current TPRPD spectrogram; and the inductor is used for being connected in a test loop of the direct-current electric equipment and simulating the direct-current PD source to output an adjustable transient current pulse train in the test loop of the direct-current electric equipment based on the transient current pulse train injected into the inductor.

Description

Technical Field

[0001] The invention relates to the technical field of direct current partial discharge testing, and in particular to a portable direct current partial discharge current pulse group generating system and an equipment detection method thereof. Background Art

[0002] During the operation of high-voltage DC electrical equipment (such as converter transformers and DC cables), the insulation system may cause partial discharge (PD) due to various reasons such as electrical corrosion, vibration wear cracking, thermal decomposition and moisture. Therefore, the PD signal often contains the gradual process information of insulation degradation and performance degradation, making PD detection the most core means to control the quality and operation status of such main equipment throughout the life cycle. The PD source inside the equipment continuously generates a single ns-level rising edge current pulse. The ultra-wideband method (including high-frequency method) is used to detect the current pulse generated by the DC PD source. As the most commonly used technical means at present, it is used to carry out daily live detection and online monitoring of converter transformers and DC cable equipment. These instruments and systems for PD live detection and online monitoring are delivered to users after type tests and factory tests required by relevant standards. However, for users such as power supply companies, there is a lack of relevant technical means to judge and evaluate whether the instruments used and the online monitoring systems that have been put into operation can work normally and meet the requirements of DC PD detection.

[0003] The commonly used judgment method is to entrust a professional organization to set defects (tips, air gaps, suspensions, etc.) in the laboratory real equipment, conduct high-voltage tests, and cause the defects to discharge stably to simulate the PD source formed by insulation defects to determine whether the ultra-wideband method (including high-frequency method) DC PD instrument or online monitoring system can work normally, and determine whether the test results given by the algorithm are consistent with the set defect model type. This working mode is time-consuming and laborious to carry out. Users such as power supply companies need to transport the equipment to the inspection unit, and it cannot be performed for online monitoring systems that have been installed on site.

[0004] Therefore, how to design a portable DC partial discharge current pulse group generation system and realize the detection of PD detection instruments or online monitoring systems based on it is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a portable DC partial discharge current pulse group generating system and a device detection method thereof, so as to solve the problem of lack of a portable DC partial discharge current pulse group generating system and a matching device detection method in the prior art.

[0006] In one aspect, the present invention provides a portable DC partial discharge current pulse group generating system, the generating system comprising a central processing unit, a current pulse-time sequence generator and an inductor; wherein,

[0007] The central processing unit is used to load the algorithm file of the abc equivalent model and construct a reference DC TPRPD spectrum;

[0008] A current pulse-time series generator, used to generate a corresponding transient current pulse group according to the reference DC TPRPD spectrum;

[0009] The inductor is used to be connected in the test circuit of the DC electrical equipment, and based on the transient current pulse group injected into the inductor, simulate the DC PD source output adjustable transient current pulse group in the test circuit of the DC electrical equipment.

[0010] On the basis of the above scheme, the present invention also makes the following improvements:

[0011] Furthermore, the abc equivalent model refers to the abc equivalent model of the internal insulation defect air gap of the DC electrical equipment.

[0012] Furthermore, by adjusting the amplitude strength of the transient pulse group injected into the inductor, a corresponding adjustable transient current pulse group is induced on the conductor or grounding wire of the test loop of the DC electrical equipment.

[0013] Furthermore, the sensor adopts an ultra-wideband current transformer.

[0014] Furthermore, the generation system further comprises a mobile terminal and a communication module; the mobile terminal is connected to the central processor via the communication module; wherein,

[0015] The mobile terminal is used to pre-store the algorithm file of the abc equivalent model and transmit it to the central processing unit via the communication module.

[0016] Furthermore, the generating system further comprises a power supply module and a human-computer interaction module; wherein,

[0017] The power supply module is used to supply power to the human-computer interaction module, the central processing unit, the current pulse-time sequence generator and the communication module;

[0018] The human-computer interaction module is used to obtain and display the status of the power module, the central processing unit, the current pulse-time sequence generator and the communication module.

[0019] Furthermore, the power module, human-computer interaction module, central processing unit, current pulse-time sequence generator and communication module form an integrated device; the integrated device is connected to the sensor via a coaxial cable and connected to the mobile terminal via a wireless or wired communication module.

[0020] On the other hand, the present invention also provides a device detection method based on the portable DC partial discharge current pulse group generating system, the device detection method comprising:

[0021] Take the PD detection instrument or online monitoring system used in the actual detection scenario of DC electrical equipment as the device under test, and select the sensor according to the device under test;

[0022] The central processing unit loads the algorithm file of the abc equivalent model, constructs a reference DC TARPD spectrum, and generates a transient current pulse group by the current pulse-time series generator, and outputs the transient current pulse group to the sensor;

[0023] The sensor simulates a DC PD source to output an adjustable transient current pulse group in a test circuit of the DC electrical equipment based on the received transient current pulse group;

[0024] The device under test detects the adjustable transient current pulse group and records the test DC PRPD spectrum; by comparing the reference DC TARPD spectrum with the test DC PRPD spectrum, it is determined whether the device under test is working normally.

[0025] On the basis of the above scheme, the present invention also makes the following improvements:

[0026] Further, the sensor is selected according to the device under test, and the following is performed:

[0027] If the system under test includes multiple ultra-wideband current transformers, one of them is selected as the sensor; if the system under test has only one ultra-wideband current transformer, a card-mounted ultra-wideband current transformer is configured as the sensor.

[0028] Furthermore, by comparing the reference DC TARPD spectrum with the test DC PRPD spectrum, it is determined whether the device under test is working properly. Execute:

[0029] The difference between the reference DC TARPD spectrum and the test DC PRPD spectrum is compared according to the given judgment basis. If the difference between the two is not higher than the preset difference threshold, it indicates that the device under test is working normally; otherwise, the device under test is working abnormally.

[0030] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0031] The portable DC partial discharge current pulse group generating system provided by the present invention, through the cooperation of the central processing unit, the current pulse-time series generator and the sensor, makes the amplitude intensity of each transient current pulse in the transient current pulse group adjustable, can truly simulate the signal generated by the DC PD source in both the time domain and the frequency domain, and the time distribution characteristics are also consistent with the real DC PD source, thereby well simulating the generation process of the DC partial discharge current pulse group. In addition, the system adopts a portable, integrated device with a visual input window, and can also select different sensors according to actual conditions, and inject the signal of the transient current pulse group into the selected sensor, which can well adapt to different working scenes and meet on-site needs, and well solves the problem of the lack of portable DC partial discharge current pulse group generating system in the prior art, and provides strong technical guidance for the relevant technical field.

[0032] In addition, the present invention also provides an equipment detection method based on a portable DC partial discharge current pulse group generating system, which utilizes the above-mentioned generating system to induce an adjustable transient current pulse group, detects the adjustable transient current pulse group through the device under test (DC PD instrument or online monitoring system based on ultra-wide band method), and compares the reference DC TARPD spectrum with the test DC PRPD spectrum to determine whether the device under test is working normally, thereby providing a relatively fast equipment detection method, which effectively solves the problem that users such as power supply companies have no technical means to judge and evaluate whether the DC PD instrument or online monitoring system based on ultra-wide band method (including high frequency method) can work normally and meet the requirements of DC PD detection.

[0033] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components;

[0035] Figure 1 A schematic diagram of the structure of a portable DC partial discharge current pulse group generating system provided in Example 1 of the present invention;

[0036] Figure 2 The abc equivalent model of the internal insulation defect air gap of the DC electrical equipment provided in Example 1 of the present invention;

[0037] Figure 3 A DC TARPD spectrum constructed by the abc equivalent model provided in Example 1 of the present invention;

[0038] Figure 4 A schematic diagram of a single transient current pulse provided in Example 1 of the present invention;

[0039] Figure 5 A schematic structural diagram of another portable DC partial discharge current pulse group generating system provided in Example 1 of the present invention;

[0040] Figure 6 This is a flow chart of a device detection method based on a portable DC partial discharge current pulse group generating system provided in Example 2 of the present invention.

[0041] Figure 7 The present invention is a schematic diagram of the equipment detection connection relationship when the DC electrical equipment is a converter transformer.

[0042] Figure 8 The present invention is a schematic diagram of the equipment detection connection relationship when the DC electrical equipment is a DC cable. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0044] Specific embodiment 1 of the present invention provides a portable DC partial discharge current pulse group generating system, the structural schematic diagram is as follows Figure 1 As shown, the system includes a central processing unit, a current pulse-time sequence generator and a sensor; the functions of each component are described as follows.

[0045] (1) A central processing unit, used to load the algorithm file of the abc equivalent model and construct a reference DC TPRPD spectrum.

[0046] The DC TPRPD spectrum, i.e., the peak-time series (qt), is constructed by the central processor after loading the algorithm file (.txt) of the abc equivalent model. In order to distinguish it from the DC TPRPD spectrum detected by the PD detection instrument or the online monitoring system, the constructed DC TPRPD spectrum is called the reference DC TPRPD spectrum. The structural diagram of the abc equivalent model of the internal insulation defect air gap of DC electrical equipment is shown in Figure 2 Below, the algorithm file of the abc equivalent model of the internal insulation defect air gap of DC electrical equipment is described as follows.

[0047] The algorithm file for loading the abc equivalent model mainly consists of equations (1) to (4). Assuming that no discharge occurs in the air gap during the pressurization process (one of the assumptions for solving the model, after the defect charging time is reached, the abc equivalent model will discharge, that is, the voltage will suddenly change), consider the RC hybrid circuit connected to a DC voltage source at time t=0, and solve the zero-state response of the circuit under the excitation of the step voltage U0. Figure 2 In the equation, b represents the defect, a is the insulating medium in series with the defect, and c is the insulating medium other than a. The following circuit equation can be established:

[0048]

[0049] Among them, U a , U b Respectively represent the capacitance C corresponding to a and b a , C b The voltage across the terminals, i b1 、i b2 、i a1 、i a2 Respectively represent the flow through R b , C b , R a , C a of current.

[0050] Formula (1) is simplified to:

[0051] C ba Ud b / dt+U b R ba / (R b R a )=U0 / R a (2)

[0052] Where: C ba =C b +C a ; R ba =R b +R a .

[0053] Solving equation (2) yields:

[0054] U b (t) = R b U0 / R ba +U0(C a / C ba -R a / R ba ) -t / τ (3)

[0055] Where: τ represents the defect charging time constant, τ=Rb R a / (R ba C ba ).

[0056] By C a / C ba Much smaller than R a / R ba , formula (3) can be simplified as:

[0057] U b (t) = R b / R ba (1-e -t / τ )U0 (4)

[0058] Thus, the occurrence time t can be randomly set, and the peak-time series (qt) is subsequently formed, q = C b *U b The DC TPRPD spectrum is q(i)-t(i), that is, the peak-time series, the horizontal axis is the occurrence time t(i), and the vertical axis is the discharge amount q(i). An example of a DC TPRPD spectrum is shown below: Figure 3 shown.

[0059] (2) A current pulse-time series generator, used to generate a corresponding transient current pulse group according to a reference DC TPRPD spectrum.

[0060] Specifically, the current pulse-time sequence generator can generate the corresponding transient current pulse group in the following manner: according to the DC TPRPD spectrum, the corresponding peak-time distribution characteristics are generated, and all single transient current pulses that meet the peak corresponding rising edge time less than 10ns, half-peak width time less than 50ns, and duration less than 100ns are selected to form a transient current pulse group, that is, a current pulse-time sequence, and output it to the sensor. The schematic diagram of a single transient current pulse is shown in FIG. Figure 4 As shown. Rising edge time t r , half peak width time t w , peak duration t l Respectively expressed as:

[0061] t r =t 90％ -t 10％ (5)

[0062] t w =t 50％ -t0 (6)

[0063] t l =t 10％' -t 10％ (7)

[0064] Among them, A peak Indicates the peak value of the transient current pulse, t 50％ Indicates A peak *0.5 corresponds to the second moment (ns); t0 represents the moment (ns) corresponding to the apparent zero point of the transient current pulse. According to the equation of the straight line formed by the 90% and 10% points at the rising edge in formula (4):

[0065]

[0066] Available,

[0067]

[0068] Where, t represents time, A represents peak value; t 10％' Indicates the transient current pulse peak value A peak *The second moment corresponding to 0.1 (ns). 10％ , A 90％ They represent the amplitudes corresponding to 10% and 90% of the transient current pulse rising edge, t 10％ ,t 90％ They respectively represent the time corresponding to 10% and 90% of the rising edge of the transient current pulse.

[0069] (3) An inductor is used to be connected in a test circuit of a DC electrical equipment and to simulate a DC PD source outputting an adjustable transient current pulse group in the test circuit of the DC electrical equipment based on the transient current pulse group injected into the inductor.

[0070] In the specific implementation process, an adjustable current pulse group simulating the output of a DC PD source can be generated in the test circuit of the DC electrical equipment through the inductor, that is, an adjustable transient current pulse-time series. In the specific implementation process, by adjusting the amplitude strength of the transient pulse group injected into the inductor, a corresponding adjustable transient current pulse group is induced on the conductor or ground wire of the test circuit of the DC electrical equipment, and the amplitude strength of the transient pulse group can be adjusted in the manner of 5pC-50pC-500pC.

[0071] Preferably, the sensor adopts an ultra-wideband current transformer, which is consistent with the ultra-wideband current transformer used in the PD detection instrument or online monitoring system based on the ultra-wideband method (including the high-frequency method). For example, the ultra-wideband current transformer can be a Rogowski coil, and the operating frequency band can be set to 20kHz~50MHz. Common sensors mainly include: card-mounted Rogowski coil, high-frequency current transformer (HFCT), and flexible windable current transformer. In the specific implementation process, adaptive selection can be made according to actual conditions to facilitate the arrangement of the wires or ground wires of the equipment body in a through-core manner. When a transient current pulse group is injected into the sensor, a corresponding adjustable transient current pulse group is induced on the wires or ground wires of the test loop of the DC electrical equipment.

[0072] Preferably, the generating system in this embodiment may further include a mobile terminal and a communication module; the mobile terminal is connected to the central processing unit via the communication module; wherein the mobile terminal is used to pre-store the algorithm file of the abc equivalent model and transmit it to the central processing unit via the communication module.

[0073] In addition, the generating system in this embodiment may also include a power module and a human-computer interaction module. The power module is used to supply power to the human-computer interaction module, the central processing unit, the current pulse-time sequence generator and the communication module, and can be charged by a common USB interface or the like. The human-computer interaction module is used to obtain and display the status of the power module, the central processing unit, the current pulse-time sequence generator and the communication module.

[0074] For practical application, the power module, human-computer interaction module, central processing unit, current pulse-time sequence generator and communication module form an integrated device; the integrated device is connected to the sensor through a coaxial cable, and connected to the mobile terminal through a wireless or wired communication module. At this time, the structural diagram of the generating system is as follows Figure 5 shown.

[0075] In actual application, the human-computer interaction module can be used to obtain and display the status of the power module, the central processing unit, the current pulse-time sequence generator and the communication module; it is also used to provide a human-computer interaction interface so that the user can set the status of the integrated device and provide corresponding display values ​​for the status of the integrated device, including the power of the power module, the working status of the current pulse-time sequence generator and the communication module, etc. It can also provide manual input means when the communication module cannot communicate with the mobile terminal, such as the status settings of the integrated device restart, the current pulse-time sequence generator pause, restart, and cycle repetition, etc. In addition, the communication module supports data interaction between the integrated device and the mobile terminal, so that the user can understand the overall status of the integrated device based on the mobile terminal, parameter setting and system control, etc.; data communication can usually be achieved by wire (I / O serial or parallel interface, optical fiber, etc.) and wireless (such as Rola, wifi, etc.). The mobile terminal can be a portable smart device such as a smartphone, tablet, or laptop computer equipped with software for maintaining data communication with the integrated device. The software installed on the mobile terminal can load the DC TARPD spectrum constructed by the algorithm file of the abc equivalent model, which is convenient for operators to observe. In addition, in addition to supporting the main data processing functions of the integrated device, the central processor can also be equipped with many different additional functions, such as device self-testing, self-diagnosis, external environmental parameter monitoring, external process control records, and data storage.

[0076] Embodiment 2 of the present invention discloses a device detection method based on a portable DC partial discharge current pulse group generating system, the flow chart is as follows: Figure 6 As shown, the device detection method includes the following steps.

[0077] Step S1: A PD detection instrument or an online monitoring system used in an actual detection scenario of DC electrical equipment is used as the device under test, and a sensor is selected according to the device under test.

[0078] Specifically, in this embodiment, the DC electrical equipment may be a converter transformer and a DC cable. In the actual detection scenario of DC electrical equipment, the sensor can be selected according to the actual situation of the PD detection instrument or online monitoring system used by the ultra-wideband method (including the high-frequency method). Preferably, if the system under test includes multiple ultra-wideband current transformers, one of them is selected as the sensor; if the system under test has only one ultra-wideband current transformer, a card-mounted ultra-wideband current transformer is configured as the sensor.

[0079] In the specific implementation process, generally speaking, for a PD detection instrument or online monitoring system: if it includes multiple ultra-wideband current transformers, one of them is selected as the sensor, and the remaining ultra-wideband current transformers are connected to the device under test as the tested object. At this time, the device detection connection relationship is as follows: Figure 7 As shown; if there is only one ultra-wideband current transformer, a card-mounted ultra-wideband current transformer can be configured as a sensor. The device detection connection relationship at this time is as follows Figure 8 shown.

[0080] Step S2: The central processing unit loads the algorithm file of the abc equivalent model, constructs a reference DC TARPD spectrum, and generates a transient current pulse group by a current pulse-time sequence generator, and outputs the transient current pulse group to the sensor.

[0081] Step S3: Based on the received transient current pulse group, the sensor simulates the DC PD source to output an adjustable transient current pulse group in the test circuit of the DC electrical equipment.

[0082] In the specific implementation process, the maximum amplitude (peak value) of the transient current pulse group can be adjusted according to the discharge amount of 5pC, 50pC and 500pC, so as to form an adjustable transient current pulse group generated by a simulated DC PD source in the test circuit of the DC electrical equipment.

[0083] Step S4: the device under test detects the adjustable transient current pulse group and records the test DC PRPD spectrum; by comparing the reference DC TARPD spectrum with the test DC PRPD spectrum, it is determined whether the device under test is working normally.

[0084] In the specific implementation process, the difference between the reference DC TARPD spectrum and the test DC PRPD spectrum can be compared according to the given judgment basis. If the difference between the two is not higher than the preset difference threshold, it indicates that the device under test has detected the air gap defect and is working normally, which can meet the requirements of PD detection; otherwise, the device under test is working abnormally and cannot meet the requirements of PD detection. Exemplarily, the given judgment standard can be: the cumulative deviation (discharge deviation) and (time deviation) of the two at all time points on the spectrum are not greater than 5%.

[0085] In addition, during the specific implementation process, after step S1, the following step may be added: using a mobile terminal to send the algorithm file of the above-mentioned abc equivalent model to the integrated device.

[0086] Based on the above equipment detection method, it is possible to conveniently and quickly determine whether the equipment under test (i.e., the DC PD detection instrument or online monitoring system of the DC electrical equipment) can work normally and meet the DC PD detection requirements.

[0087] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0088] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A portable DC partial discharge current pulse group generating system, characterized in that: The generating system includes a central processing unit, a current pulse-time sequence generator and a sensor; wherein, The central processing unit is used to load the algorithm file of the abc equivalent model and construct a reference DC TPRPD spectrum; A current pulse-time series generator, used to generate a corresponding transient current pulse group according to the reference DC TPRPD spectrum; The inductor is used to be connected in the test circuit of the DC electrical equipment, and based on the transient current pulse group injected into the inductor, simulate the DC PD source output adjustable transient current pulse group in the test circuit of the DC electrical equipment.

2. The portable DC partial discharge current pulse group generating system according to claim 1, characterized in that: The abc equivalent model refers to the abc equivalent model of the internal insulation defect air gap of DC electrical equipment.

3. The portable DC partial discharge current pulse group generating system according to claim 2, characterized in that: By adjusting the amplitude strength of the transient pulse group injected into the inductor, a corresponding adjustable transient current pulse group is induced on the conductor or grounding wire of the test loop of the DC electrical equipment.

4. The portable DC partial discharge current pulse group generating system according to claim 3 is characterized in that: The inductor adopts an ultra-wideband current transformer.

5. The portable DC partial discharge current pulse group generating system according to claim 4, characterized in that: The generation system also includes a mobile terminal and a communication module; the mobile terminal is connected to the central processor via the communication module; wherein, The mobile terminal is used to pre-store the algorithm file of the abc equivalent model and transmit it to the central processing unit via the communication module.

6. The portable DC partial discharge current pulse group generating system according to claim 5, characterized in that: The generating system also includes a power supply module and a human-computer interaction module; wherein, The power supply module is used to supply power to the human-computer interaction module, the central processing unit, the current pulse-time sequence generator and the communication module; The human-computer interaction module is used to obtain and display the status of the power module, the central processing unit, the current pulse-time sequence generator and the communication module.

7. The portable DC partial discharge current pulse group generating system according to claim 6, characterized in that: The power module, human-computer interaction module, central processing unit, current pulse-time sequence generator and communication module form an integrated device; the integrated device is connected to the sensor via a coaxial cable and connected to the mobile terminal via a wireless or wired communication module.

8. A device detection method based on the portable DC partial discharge current pulse group generating system according to any one of claims 1 to 7, characterized in that: The device detection method comprises: Take the PD detection instrument or online monitoring system used in the actual detection scenario of DC electrical equipment as the device under test, and select the sensor according to the device under test; The central processing unit loads the algorithm file of the abc equivalent model, constructs a reference DC TARPD spectrum, and generates a transient current pulse group by the current pulse-time series generator, and outputs the transient current pulse group to the sensor; The sensor simulates a DC PD source to output an adjustable transient current pulse group in a test circuit of the DC electrical equipment based on the received transient current pulse group; The device under test detects the adjustable transient current pulse group and records the test DC PRPD spectrum; by comparing the reference DC TARPD spectrum with the test DC PRPD spectrum, it is determined whether the device under test is working normally.

9. The device detection method based on the portable DC partial discharge current pulse group generating system according to claim 8 is characterized in that: The sensor is selected according to the device under test and the following is performed: If the system under test includes multiple ultra-wideband current transformers, one of them is selected as the sensor; if the system under test has only one ultra-wideband current transformer, a card-mounted ultra-wideband current transformer is configured as the sensor.

10. The device detection method based on the portable DC partial discharge current pulse group generating system according to claim 8 or 9, characterized in that: By comparing the reference DC TARPD spectrum with the test DC PRPD spectrum, determine whether the device under test is working properly. Execute: The difference between the reference DC TARPD spectrum and the test DC PRPD spectrum is compared according to the given judgment basis. If the difference between the two is not higher than the preset difference threshold, it indicates that the device under test is working normally; otherwise, the device under test is working abnormally.

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