Power cabinet partial discharge monitoring device and method

Abstract

The invention discloses a power cabinet partial discharge monitoring device and method. The power cabinet partial discharge monitoring device comprises a detection module, a main control module and a three-phase acquisition sub-node module. The detection module is used for capturing a sound signal and / or an optical signal in the power cabinet; the main control module is used for judging whether suspected discharge occurs or not according to the detection signal and outputting a communication driving signal when the suspected discharge is determined to occur; the three-phase acquisition sub-node module is used for carrying out carrier communication with a communication network main node module in an upstream concentrator of the power cabinet in response to the communication driving signal, and feeding back the received signal strength of each phase of communication signal in three-phase communication signals from the communication network main node module to the main control module; and the main control module judges whether discharge occurs or not according to the received signal strength of each phase and judges the phase of the discharge when determining that the discharge occurs. The main control module can accurately identify the discharge condition and position the discharge, so that the reliability and the safety are improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a device and method for monitoring partial discharge of an electric power cabinet. Background Art

[0002] Partial discharge (PD) in distribution cabinets refers to localized electrical discharges caused by defects or uneven stress in the insulation materials within the cabinet. Although these discharges do not penetrate the conductors, they can gradually degrade the insulation, threatening equipment safety. PD is typically caused by air gaps, impurities, or mechanical damage, resulting in local electric field strength exceeding the insulation's tolerance limit. Discharge types include internal discharge (solid insulation defects), surface discharge (contamination or moisture), and corona discharge (sharp edges). Discharge in distribution cabinets can carbonize and age the materials, shortening equipment lifespan and potentially causing fires and even paralyzing the distribution system.

[0003] Currently, there are many methods for local fault monitoring in distribution cabinets. The core methods include electrical measurement (such as pulse current and high-frequency current monitoring) and non-electrical measurement methods (such as optical detection, ultrasonic detection, transient ground wave monitoring, and ultra-high frequency monitoring). In practical applications, a combination of these methods is often used to improve monitoring accuracy.

[0004] However, these monitoring methods mainly capture the sound, current or high-frequency signals generated when the discharge occurs. It is difficult to locate the discharge after the discharge occurs and whether it is caused by other non-discharge reasons. Summary of the Invention

[0005] In view of the above problems, the present application provides a partial discharge monitoring device and method for a power cabinet to solve the above technical problems.

[0006] In a first aspect, the present application provides a partial discharge monitoring device for a power cabinet, the partial discharge monitoring device for a power cabinet comprising a detection module, a main control module and a three-phase acquisition sub-node module;

[0007] A detection module, used to capture sound signals and / or light signals in the power cabinet to obtain a detection signal;

[0008] The main control module is connected to the detection module and is used to determine whether a suspected discharge occurs based on the detection signal, and output a communication drive signal when it is determined that a suspected discharge occurs;

[0009] The three-phase acquisition sub-node module is connected to the main control module and is used to respond to the communication drive signal to perform carrier communication with the communication network main node module in the upstream communication equipment of the power cabinet, and feed back the received signal strength of each phase communication signal in the three-phase communication signal from the communication network main node module to the main control module, so that the main control module determines whether discharge occurs based on the received signal strength of each phase and determines the phase of discharge when it is determined that discharge occurs.

[0010] In one possible implementation of the present application, the main control module is used to:

[0011] Compare the received signal strength of each phase with the initial signal strength of each phase;

[0012] If the difference between the initial signal strength of one of the three phases and the received signal strength of the phase is greater than or equal to a preset judgment threshold, it is determined that the discharge occurs, and the discharge occurs in the phase;

[0013] If the difference between the initial signal strength of one of the three phases and the received signal strength of that phase is greater than or equal to a preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that discharge has occurred, and the discharge occurs between one of the phases and at least one of the other two phases.

[0014] In one possible implementation of the present application, the main control module is further configured to:

[0015] When determining that a discharge has occurred, a target discharge level interval corresponding to a signal drop amplitude is determined according to a plurality of preset discharge level intervals to determine the severity of the discharge of the current line; wherein the signal drop amplitude is the difference between the initial signal strength of the discharge phase and the received signal strength.

[0016] In one possible implementation of the present application, the main control module is further configured to:

[0017] When it is determined that no discharge occurs in the power cabinet, the three-phase data acquisition sub-node module is controlled to establish a network with the communication network main node module and communicate phase by phase;

[0018] According to the received signal strength of each phase fed back by the three-phase acquisition sub-node module, the initial signal strength of each phase is obtained.

[0019] In one possible implementation of the present application, the main control module is used to:

[0020] If the intensity of the ultrasonic signal and the intensity of the light-sensing signal in the detection signal both reach the set start threshold, the ultrasonic signal is analyzed;

[0021] When the waveform amplitude of the ultrasonic signal is greater than a preset amplitude threshold, it is determined that a suspected discharge has occurred.

[0022] In a second aspect, the present application provides a method for monitoring partial discharge in a power cabinet, the method comprising:

[0023] Obtaining a detection signal from a detection module and determining whether a suspected discharge has occurred based on the detection signal; wherein the detection module is disposed inside the power cabinet to capture sound signals and / or light signals inside the power cabinet to obtain the detection signal;

[0024] If suspected discharge is determined to have occurred, a communication drive signal is generated and output to the three-phase acquisition sub-node module; wherein the three-phase acquisition sub-node module is arranged inside the power cabinet and is communicatively connected to the communication network main node module of the communication equipment upstream of the power cabinet;

[0025] Obtain the received signal strength of each phase fed back by the three-phase acquisition sub-node module, determine whether discharge occurs based on the received signal strength of each phase, and determine the phase of the discharge when it is determined that discharge occurs; wherein, the received signal strength of each phase is the signal strength of each phase communication signal in the three-phase communication signal received from the communication network main node module when the three-phase acquisition sub-node module responds to the communication drive signal and performs carrier communication with the communication network main node module.

[0026] In a possible implementation of the present application, determining whether discharge occurs according to the received signal strength of each phase and determining the phase of the discharge when discharge occurs includes:

[0027] Compare the received signal strength of each phase with the initial signal strength of each phase;

[0028] If the difference between the initial signal strength of one of the three phases and the received signal strength of the phase is greater than or equal to a preset judgment threshold, it is determined that a discharge occurs, and the discharge occurs in the phase;

[0029] If the difference between the initial signal strength of one of the three phases and the received signal strength of that phase is greater than or equal to a preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that discharge has occurred, and the discharge occurs between one of the phases and at least one of the other two phases.

[0030] In a possible implementation of the present application, after determining that a discharge occurs, the method further includes:

[0031] The target discharge level interval corresponding to the signal drop amplitude is determined according to the preset multiple discharge level intervals to determine the discharge severity of the current line; wherein the signal drop amplitude is the difference between the initial signal strength of the discharge phase and the received signal strength.

[0032] In one possible implementation of the present application, before comparing the received signal strength of each phase with the initial signal strength of each corresponding phase, the method further includes:

[0033] When it is determined that no discharge occurs in the power cabinet, a networking communication signal is generated and output to the three-phase acquisition sub-node module, so that the three-phase acquisition sub-node module and the communication network main node module establish a network and communicate phase by phase;

[0034] According to the received signal strength of each phase fed back by the three-phase acquisition sub-node module, the initial signal strength of each phase is obtained.

[0035] In one possible implementation of the present application, the detection signal includes an ultrasonic signal and a light-sensing signal, and determining whether a suspected discharge occurs based on the detection signal includes:

[0036] If the intensity of the ultrasonic signal and the intensity of the light-sensing signal both reach the set start threshold, the ultrasonic signal is analyzed;

[0037] When the waveform amplitude of the ultrasonic signal is greater than a preset amplitude threshold, it is determined that a suspected discharge has occurred.

[0038] From the above content, it can be concluded that this application has the following beneficial effects:

[0039] In the present application, the sound signal and / or light signal in the power cabinet is captured by the detection module, and the obtained detection signal is transmitted to the main control module, so that the main control module can determine whether a suspected discharge occurs based on the detection signal. If it is determined that a suspected discharge occurs, the main control module outputs a communication drive signal to the three-phase acquisition sub-node module, so that the three-phase acquisition sub-node module performs carrier communication with the communication network main node module in the upstream communication equipment of the power cabinet, and feeds back the received signal strength of each phase in the three phases to the main control module, so that the main control module can determine whether a discharge occurs based on the received signal strength of each phase and locate the phase where the discharge occurs when it is determined that a discharge occurs, which greatly improves the safety and reliability of the power cabinet and facilitates troubleshooting and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 It is an equivalent circuit diagram when the distribution cabinet discharges;

[0042] Figure 2 This is another equivalent circuit diagram when the distribution cabinet discharges;

[0043] Figure 3 This is another equivalent circuit diagram when the distribution cabinet discharges;

[0044] Figure 4 This is a structural diagram of a partial discharge monitoring device for a power cabinet provided in an embodiment of the present application;

[0045] Figure 5This is a flow chart of a method for monitoring partial discharge in a power cabinet provided in an embodiment of the present application;

[0046] Figure 6 Schematic diagram of a waveform of an ultrasonic signal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0048] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0049] In the embodiments of the present application, it should be noted that, in this document, relational terms such as first and second, etc., are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0050] Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not explicitly listed or inherent to such article or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the article or device comprising the element.

[0051] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0052] In addition, in the embodiments of the present application, "plurality" refers to two or more. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two, or more. For example, "including at least one" means including one, two, or more, and does not limit which ones are included. For example, "including at least one of A, B, and C" means including A, B, C, A and B, A and C, B and C, or A, B, and C.

[0053] Distribution cabinets, typically located at the first level of primary power distribution, are crucial components of the system. Power from distribution transformers is distributed to users via distribution cabinets. Partial discharge (PD) in distribution cabinets refers to localized electrical discharges caused by defects or uneven stress in the insulation materials within the cabinet. PD primarily occurs within distribution cabinets or within their insulation systems. This is due to a variety of factors, including the design and construction of the equipment itself and the external operating environment, all of which contribute to PD.

[0054] The following are the common reasons why distribution cabinets produce more serious discharges: First, during long-term use, the insulation materials inside the equipment will gradually age, resulting in a decrease in insulation performance. Aged insulation materials are prone to defects such as cracks and bubbles, which in turn cause partial discharge. Second, environmental factors also have a great impact on the operation of high-voltage cabinets. For example, harsh environments such as high temperature and high humidity will accelerate the aging of insulation materials and increase the risk of partial discharge. In addition, dust and pollutants may also adhere to the surface of the insulation material, reducing its insulation performance. Third, installation factors. If there are problems such as poor wiring and loose fasteners during installation, partial discharge may occur.

[0055] When the distribution cabinet is in good condition, the overall line performance is very good, and the output from the transformer to the switch cabinet is equivalent to a very small resistance. When insulation aging or contaminants cause local discharge, the metal wire and the discharge part, such as the metal tip, are usually equivalent to a large resistor and bypass capacitor. Poor wiring or loose fasteners will cause the overall line resistance to increase and form an equivalent discharge capacitor at the poor location. Another case is that the insulation between phases becomes smaller, resulting in discharge. The equivalent circuits of these three cases are as follows Figures 1 to 3 IN(A / B) indicates the input side, and OUT(A / B) indicates the output side.

[0056] As can be seen from the figure, when the line is functioning properly, the impedance between the line and ground or the discharge point is large, preventing discharge. When a problem occurs, the equivalent impedance to ground near the discharge point is low, causing a discharge. This discharge generates light and sound signals. If high-frequency HPLC (High-Speed ​​Power Line Communication) signals are transmitted on the line, changes in the line's equivalent impedance will inevitably have a significant impact on the signal quality.

[0057] Many related partial discharge detection systems use a combination of acoustics and optics for monitoring. However, due to the multiple sources of acoustics and optics, misjudgments can sometimes occur, and it is difficult to determine the discharge phase and type.

[0058] Based on this, the embodiments of the present application provide a device and method for monitoring partial discharge in a power cabinet. By combining acoustic and optical detection with HPLC power line carrier communication, it is possible to more accurately determine whether discharge has occurred and locate the discharge, thereby improving safety and reliability.

[0059] The power cabinet partial discharge monitoring device and method provided in this application are described in detail below.

[0060] First, the present invention provides a partial discharge monitoring device for a power cabinet. Figure 4 , Figure 4 It is a structural schematic diagram of a partial discharge monitoring device for a power cabinet provided in an embodiment of the present application. The partial discharge monitoring device 100 for a power cabinet may include a detection module 110, a main control module 120 and a three-phase acquisition sub-node module 130; the detection module 110 can be used to capture sound signals and / or light signals in the power cabinet to obtain a detection signal; the main control module 120 is connected to the detection module 110, and is used to determine whether a suspected discharge has occurred based on the detection signal, and output a communication drive signal when it is determined that a suspected discharge has occurred; the three-phase acquisition sub-node module 130 is connected to the main control module 120, and can be used to respond to the communication drive signal and perform carrier communication with the communication network main node module 200 in the upstream communication equipment of the power cabinet, and feed back the received signal strength of each phase communication signal in the three-phase communication signal from the communication network main node module 200 to the main control module 120, so that the main control module 120 determines whether a discharge has occurred based on the received signal strength of each phase and determines the phase of the discharge when it is determined that a discharge has occurred.

[0061] In an embodiment of the present application, the detection module 110 may include any existing sensor capable of detecting ambient sound, such as an ultrasonic sensor, a piezoelectric sound sensor, etc. Taking an ultrasonic sensor as an example, the ultrasonic sensor can be used to detect sound signals within the power cabinet. The detection module 110 may also include any existing sensor capable of detecting ambient light, such as an ambient light sensor, which can be used to detect light signals within the power cabinet. Therefore, the detection signal may be one or both of an ultrasonic signal and a light-sensing signal, which may be determined based on the actual application scenario and is not limited here.

[0062] The main control module 120 can be any existing controller, including but not limited to a system on chip (SOC), a microcontroller unit (MCU), a central processing unit (CPU), etc. The main control module 120 can be in communication with the detection module 110, thereby making a preliminary judgment on discharge based on the detection signal from the detection module 110. If the detection signal determines that discharge is suspected to have occurred, the main control module 120 outputs a communication drive signal to the three-phase acquisition sub-node module 130.

[0063] The three-phase interface of the three-phase acquisition sub-node module 130 can be connected to the output side of a power cabinet, such as a distribution cabinet. The three-phase acquisition sub-node module 130 is communicatively connected to an upstream communication device, such as a communication network master node module 200 in a concentrator, via the three-phase interface. The three-phase acquisition sub-node module 130 is also configured with a sensor for monitoring the strength of each phase of the communication signal. Thus, after receiving a communication drive signal from the main control module 120, the three-phase acquisition sub-node module 130 can respond to the communication drive signal to perform carrier communication with the communication network master node module 200, and detect the received signal strength of each phase of the communication signal through the sensors in each phase. The received signal strength of each phase is then fed back to the main control module 120, allowing the main control module 120 to determine whether a discharge has occurred within the power cabinet and, if a discharge has occurred, to determine the phase of the discharge.

[0064] It can be understood that the power cabinet partial discharge monitoring device 100 can also include a power supply 140, which provides corresponding working voltage signals to the detection module 110, the main control module 120 and the three-phase acquisition sub-node module 130 respectively, so that the detection module 110, the main control module 120 and the three-phase acquisition sub-node module 130 can operate normally.

[0065] In an embodiment of the present application, the detection module 110 captures the sound signal and / or light signal in the power cabinet, and transmits the obtained detection signal to the main control module 120, so that the main control module 120 can determine whether a suspected discharge occurs based on the detection signal. If it is determined that a suspected discharge occurs, the main control module 120 outputs a communication drive signal to the three-phase acquisition sub-node module 130, so that the three-phase acquisition sub-node module 130 performs carrier communication with the communication network main node module 200 in the upstream communication equipment of the power cabinet, and feeds back the received signal strength of each phase in the three phases to the main control module 120, so that the main control module 120 can determine whether a discharge occurs based on the received signal strength of each phase and locate the phase where the discharge occurs when it is determined that a discharge occurs, thereby greatly improving the safety and reliability of the power cabinet and facilitating troubleshooting and maintenance.

[0066] Next, continue to Figure 4 Each unit module shown and the specific implementation methods that may be used in practical applications are described in detail.

[0067] In some embodiments of the present application, the main control module 120 can be used to: compare the received signal strength of each phase with the initial signal strength of each phase; if the difference between the initial signal strength of one of the three phases and the received signal strength of the phase is greater than or equal to a preset judgment threshold, it is determined that discharge occurs, and the discharge occurs in the phase; if the difference between the initial signal strength of one of the three phases and the received signal strength of the phase is greater than or equal to a preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that discharge occurs, and the discharge occurs between one of the phases and at least one of the other two phases.

[0068] In an embodiment of the present application, the main control module 120 can compare and analyze the received signal strength of each phase of the received three-phase communication signal with the corresponding initial signal strength. If the signal strength of a phase changes significantly compared to the initial signal strength, a line abnormality is determined based on the change. If only a single phase changes, it indicates that a discharge has occurred in that phase. If the communication phase changes significantly and the non-communication phase also shows a significant increase in signal amplitude, it indicates that interphase discharge may have occurred.

[0069] That is to say, if the difference between the initial signal strength of a phase and the received signal strength of that phase is greater than or equal to the preset judgment threshold, it can be determined that the discharge occurs in that phase; and if the difference between the initial signal strength of one phase and the received signal strength of that phase is greater than or equal to the preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that the discharge occurs between one phase and at least one of the other two phases.

[0070] In the embodiment of the present application, the initial signal strength may be the received signal strength during carrier communication between the three-phase acquisition sub-node module 130 and the communication network master node module 200 when the power cabinet is installed, ensuring that no discharge occurs. It is understood that, to improve accuracy, the initial signal strength may also be the average of the received signal strengths during multiple carrier communications between the three-phase acquisition sub-node module 130 and the communication network master node module 200 when the power cabinet is installed, ensuring that no discharge occurs. The preset judgment threshold can be obtained based on past experience or multiple experiments and is not limited here.

[0071] For example, if the initial signal strength corresponding to A is a, the received signal strength of this communication or the average of the received signal strengths of multiple communications in this stage is a', and when (a'-a) is greater than or equal to the preset judgment threshold of phase A, and there are no abnormalities in phases B and C, it is determined that the discharge occurred in phase A; if not only (a'-a) is greater than or equal to the preset judgment threshold of phase A, but also the received signal strength of phase B, the non-communication phase, shows an obvious increase in signal amplitude, and there is no abnormality in phase C, then it is determined that the discharge occurred between phases A and B.

[0072] In some embodiments of the present application, the main control module 120 can also be used to: when determining that a discharge has occurred, determine the target discharge degree interval corresponding to the signal drop amplitude based on multiple preset discharge degree intervals to determine the discharge severity of the current line; wherein the signal drop amplitude is the difference between the initial signal strength of the discharge phase and the received signal strength.

[0073] In an embodiment of the present application, the severity of the discharge of the line can be judged by a discharge degree interval composed of multiple thresholds. The difference between the initial signal strength and the received signal strength of the discharge phase where the discharge occurs is compared with each threshold to determine the severity of the discharge.

[0074] For example, the discharge severity intervals include a mild discharge interval (δ0≤Δ<δ1), a moderate discharge interval (δ1≤Δ<δ2), and a severe discharge interval (Δ≥δ2). Δ represents the signal drop amplitude, or the difference between the initial signal strength and the received signal strength during the discharge phase. δ0 is the preset threshold for determining whether a discharge has occurred, while δ1 and δ2 are the thresholds used to delineate the discharge severity intervals. Based on this, the target discharge severity interval can be determined based on the signal drop amplitude Δ, thereby determining the discharge severity of the current line.

[0075] In some embodiments of the present application, the main control module 120 can also be used to: when it is determined that no discharge has occurred in the power cabinet, control the three-phase acquisition sub-node module 130 to establish a network with the communication network main node module 200, and communicate phase by phase; obtain the initial signal strength of each phase based on the received signal strength of each phase fed back by the three-phase acquisition sub-node module 130.

[0076] In an embodiment of the present application, the main control module 120 can control the three-phase acquisition sub-node module 130 to connect to the network and establish a network with the communication network main node module 200 during installation, and perform initial communication, record the received signal strength of each phase for multiple communications when the power cabinet is in good condition, that is, no discharge occurs, and use the average of the received signal strengths recorded multiple times as the initial signal strength of each phase for subsequent discharge judgment.

[0077] In some embodiments of the present application, the main control module 120 can be used to: if the intensity of the ultrasonic signal and the intensity of the light-sensing signal in the detection signal both reach the set starting threshold, then analyze the ultrasonic signal; when the waveform amplitude of the ultrasonic signal is greater than the preset amplitude threshold, determine that a suspected discharge has occurred.

[0078] In this embodiment of the present application, when both the ultrasonic signal intensity and the light-sensing signal intensity reach corresponding activation thresholds, waveform analysis of the ultrasonic signal can be performed to determine whether a suspected discharge has occurred. If the waveform amplitude of the ultrasonic signal is greater than a preset amplitude threshold, a suspected discharge can be determined. The main control module 120 can then control the three-phase acquisition sub-node module 130 to perform carrier communication to further determine and locate the discharge.

[0079] like Figure 5 As shown, based on the above embodiment, the embodiment of the present application further provides a method for monitoring partial discharge of a power cabinet, which includes the following steps:

[0080] Step S501: Obtain a detection signal from a detection module, and determine whether suspected discharge occurs based on the detection signal; wherein the detection module is set inside the power cabinet to capture sound signals and / or light signals inside the power cabinet to obtain the detection signal.

[0081] Step S502: If suspected discharge is determined to have occurred, a communication drive signal is generated and output to the three-phase acquisition sub-node module; wherein the three-phase acquisition sub-node module is arranged inside the power cabinet and is communicatively connected to the communication network main node module of the communication equipment upstream of the power cabinet.

[0082] Step S503: Obtain the received signal strength of each phase fed back by the three-phase acquisition sub-node module, determine whether discharge occurs based on the received signal strength of each phase, and determine the phase of the discharge when it is determined that discharge occurs; wherein, the received signal strength of each phase is the signal strength of each phase communication signal in the three-phase communication signal received from the communication network main node module when the three-phase acquisition sub-node module responds to the communication drive signal and performs carrier communication with the communication network main node module.

[0083] In an embodiment of the present application, the detection module 110 captures the sound signal and / or light signal in the power cabinet, and transmits the obtained detection signal to the main control module 120, so that the main control module 120 can determine whether a suspected discharge occurs based on the detection signal. If it is determined that a suspected discharge occurs, the main control module 120 outputs a communication drive signal to the three-phase acquisition sub-node module 130, so that the three-phase acquisition sub-node module 130 performs carrier communication with the communication network main node module 200 in the upstream communication equipment of the power cabinet, and feeds back the received signal strength of each phase in the three phases to the main control module 120, so that the main control module 120 can determine whether a discharge occurs based on the received signal strength of each phase and locate the phase where the discharge occurs when it is determined that a discharge occurs, thereby greatly improving the safety and reliability of the power cabinet and facilitating troubleshooting and maintenance.

[0084] In some embodiments of the present application, determining whether a discharge occurs based on the received signal strength of each phase and determining the phase of the discharge when it is determined that the discharge occurs may further include:

[0085] The received signal strength of each phase is compared with the initial signal strength of each phase; if the difference between the initial signal strength of one of the three phases and the received signal strength of that phase is greater than or equal to the preset judgment threshold, it is determined that a discharge has occurred, and the discharge has occurred in that phase; if the difference between the initial signal strength of one of the three phases and the received signal strength of that phase is greater than or equal to the preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that a discharge has occurred, and the discharge has occurred between one of the phases and at least one of the other two phases.

[0086] In some embodiments of the present application, after determining that a discharge has occurred, the method may further include: determining a target discharge degree interval corresponding to a signal drop amplitude based on a plurality of preset discharge degree intervals to determine the discharge severity of the current line; wherein the signal drop amplitude is the difference between the initial signal strength of the discharge phase and the received signal strength.

[0087] In some embodiments of the present application, the received signal strength of each phase is compared with the initial signal strength of each phase. Before that, the method may further include: when it is determined that no discharge has occurred in the power cabinet, generating a networking communication signal and outputting it to the three-phase acquisition sub-node module, so that the three-phase acquisition sub-node module and the communication network main node module establish a network and communicate phase by phase; according to the received signal strength of each phase fed back by the three-phase acquisition sub-node module, the initial signal strength of each phase is obtained.

[0088] In some embodiments of the present application, the sound and light detection signals include ultrasonic signals and light-sensing signals. Determining whether a suspected discharge has occurred based on the sound and light detection signals may further include: if the intensity of the ultrasonic signal and the intensity of the light-sensing signal both reach a set starting threshold, analyzing the ultrasonic signal; when the waveform amplitude of the ultrasonic signal is greater than a preset amplitude threshold, determining that a suspected discharge has occurred.

[0089] In the embodiment of the present application, the execution of the power cabinet partial discharge monitoring method is based on the following Figure 4 Corresponding to the power cabinet partial discharge monitoring device 100 in any embodiment, the specific implementation of each step in the method can refer to the following. Figure 4 The description of the power cabinet partial discharge monitoring device 100 in any embodiment will not be repeated here.

[0090] As an example, the power cabinet partial discharge monitoring device provided in the embodiment of the present application is installed in a normal power cabinet such as a distribution cabinet, and the three-phase wiring position of the three-phase acquisition sub-node module (HPLC STA module, also known as the site module) is the output side of the distribution cabinet. After power-on, the main control module (CPU module) first controls the HPLC STA module to access the network, and establishes a network with the upstream communication equipment, such as the communication network master node module (CCO module, also known as the central coordinator) of the concentrator (if there is no concentrator, a concentrator can be connected), and communicates phase by phase, and records the communication signal strength received by each phase from the CCO module. In this embodiment, since the CCO module and the HPLC STA module are close, the average values ​​of the received signal strengths of phases A, B, and C are -30dBm, -29dBm, and -33dBm, respectively, which are not much different. Then, an insulation defect is artificially created in phase B, resulting in discharge. At this time, both the light sensor and the ultrasonic wave reacted, and the detected waveform amplitudes exceeded 0.3V. The ultrasonic wave captured synchronously is as follows Figure 6 shown.

[0091] At this point, a discharge was suspected, but other external sources, such as light and ultrasound, could not be ruled out. Therefore, the CPU module quickly activated the HPLC STA module to report the event, enabling carrier communication between the HPLC STA module and the CCO module and recording the average received signal strength of the information returned by the CCO module. Actual testing revealed that the average received signal strength of each phase was -31dBm, -42dBm, and -33dBm. Phase B experienced a significant change, exceeding the minor threshold δ1 (6dB) and below the severe threshold δ2 (15dB). Since the other two phases showed minimal changes, it was determined that a discharge had indeed occurred within the distribution cabinet, and that the discharge location was located in phase B, consistent with the actual discharge location. Based on the analysis results, the CPU module directly reported them to the concentrator, eliminating the need for additional communication methods for other sensors to report information.

[0092] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A partial discharge monitoring device for a power cabinet, characterized in that: include: A detection module, used to capture sound signals and / or light signals in the power cabinet to obtain a detection signal; a main control module, connected to the detection module, for determining whether a suspected discharge occurs based on the detection signal, and outputting a communication drive signal when it is determined that a suspected discharge occurs; The three-phase acquisition sub-node module is connected to the main control module and is used to respond to the communication drive signal to perform carrier communication with the communication network main node module in the upstream communication equipment of the power cabinet, and feed back the received signal strength of each phase communication signal in the three-phase communication signal from the communication network main node module to the main control module, so that the main control module determines whether discharge occurs based on the received signal strength of each phase and determines the phase of discharge when it is determined that discharge occurs.

2. The partial discharge monitoring device for a power cabinet according to claim 1, characterized in that: The main control module is used for: Comparing the received signal strength of each phase with the initial signal strength of each phase; If the difference between the initial signal strength of one of the three phases and the received signal strength of the phase is greater than or equal to a preset judgment threshold, it is determined that discharge occurs, and the discharge occurs in the phase; If the difference between the initial signal strength of one of the three phases and the received signal strength of that phase is greater than or equal to the preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that discharge has occurred, and the discharge occurs between one of the phases and at least one of the other two phases.

3. The partial discharge monitoring device for a power cabinet according to claim 2, characterized in that: The main control module is also used for: When determining that a discharge has occurred, a target discharge degree interval corresponding to a signal drop amplitude is determined according to a plurality of preset discharge degree intervals to determine the discharge severity of the current line; wherein the signal drop amplitude is the difference between the initial signal strength of the discharge phase and the received signal strength.

4. The partial discharge monitoring device for a power cabinet according to claim 2, characterized in that: The main control module is also used for: When it is determined that no discharge occurs in the power cabinet, the three-phase data acquisition sub-node module is controlled to establish a network with the communication network master node module and communicate phase by phase; The initial signal strength of each corresponding phase is obtained according to the received signal strength of each phase fed back by the three-phase acquisition sub-node module.

5. The partial discharge monitoring device for a power cabinet according to any one of claims 1 to 4, characterized in that: The main control module is used for: If the intensity of the ultrasonic signal and the intensity of the light-sensing signal in the detection signal both reach a set start threshold, the ultrasonic signal is analyzed; When the waveform amplitude of the ultrasonic signal is greater than a preset amplitude threshold, it is determined that a suspected discharge occurs.

6. A method for monitoring partial discharge of a power cabinet, characterized in that: The method comprises: Obtaining a detection signal from a detection module, and determining whether a suspected discharge occurs based on the detection signal; wherein the detection module is disposed inside the power cabinet to capture sound signals and / or light signals inside the power cabinet to obtain the detection signal; If suspected discharge is determined to have occurred, a communication drive signal is generated and output to a three-phase acquisition sub-node module; wherein the three-phase acquisition sub-node module is arranged inside the power cabinet and is communicatively connected to a communication network main node module of an upstream communication device of the power cabinet; Obtain the received signal strength of each phase fed back by the three-phase acquisition sub-node module, determine whether discharge occurs based on the received signal strength of each phase, and determine the phase of the discharge when it is determined that discharge occurs; wherein, the received signal strength of each phase is the signal strength of each phase communication signal in the three-phase communication signal received from the communication network main node module when the three-phase acquisition sub-node module responds to the communication drive signal and performs carrier communication with the communication network main node module.

7. The method for monitoring partial discharge of a power cabinet according to claim 6, characterized in that: The determining whether discharge occurs according to the received signal strength of each phase and determining the phase of the discharge when it is determined that discharge occurs includes: Comparing the received signal strength of each phase with the initial signal strength of each phase; If the difference between the initial signal strength of one of the three phases and the received signal strength of the phase is greater than or equal to a preset judgment threshold, it is determined that discharge occurs, and the discharge occurs in the phase; If the difference between the initial signal strength of one of the three phases and the received signal strength of that phase is greater than or equal to the preset judgment threshold, and the received signal strength of at least one of the other two phases is greater than the signal strength when there is no communication, it is determined that discharge has occurred, and the discharge occurs between one of the phases and at least one of the other two phases.

8. The method for monitoring partial discharge of a power cabinet according to claim 7, characterized in that: After determining that a discharge occurs, the method further includes: The target discharge level interval corresponding to the signal drop amplitude is determined according to a plurality of preset discharge level intervals to determine the discharge severity of the current line; wherein the signal drop amplitude is the difference between the initial signal strength and the received signal strength of the discharge phase.

9. The method for monitoring partial discharge of a power cabinet according to claim 7, characterized in that: Before comparing the received signal strength of each phase with the initial signal strength of each phase, the method further includes: When it is determined that the power cabinet has not discharged, a networking communication signal is generated and output to the three-phase acquisition sub-node module, so that the three-phase acquisition sub-node module establishes a network with the communication network master node module and communicates phase by phase; The initial signal strength of each corresponding phase is obtained according to the received signal strength of each phase fed back by the three-phase acquisition sub-node module.

10. The method for monitoring partial discharge of a power cabinet according to any one of claims 6 to 9, characterized in that: The detection signal includes an ultrasonic signal and a light-sensing signal, and judging whether a suspected discharge occurs according to the detection signal includes: If the intensity of the ultrasonic signal and the intensity of the light-sensing signal both reach a set start threshold, analyzing the ultrasonic signal; When the waveform amplitude of the ultrasonic signal is greater than a preset amplitude threshold, it is determined that a suspected discharge occurs.

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