A partial discharge signal simulation device for power cables

Abstract

The application discloses a kind of power cable partial discharge signal simulation devices, including signal generation module, digital-analog conversion module, signal conditioning module and isolated access module, wherein, the output of signal generation module is electrically connected with the input of digital-analog conversion module, the output of digital-analog conversion module is electrically connected with the input of signal conditioning module, the output of signal conditioning module is electrically connected with the input of isolated access module, the output of isolated access module is electrically connected with cable joint.The amplified filtered partial discharge simulation signal is accessed to actual high-voltage cable by isolated access module, realizes that partial discharge simulation signal is injected into actual high-voltage cable, and improves the calibration accuracy of partial discharge detection equipment.

Description

Technical Field

[0001] This utility model belongs to the field of cable testing technology, specifically relating to a device for simulating partial discharge signals in power cables. Background Technology

[0002] As the core carrier of electrical energy transmission, the insulation condition of power cables directly determines the reliability of power grid operation. Partial discharge (PD) is an early sign of cable insulation degradation, usually caused by bubbles, cracks, or contaminants within the insulation. Therefore, partial discharge detection equipment is used to detect partial discharge in cables. Commonly used partial discharge detection equipment captures electromagnetic pulses, ultrasonic waves, or chemical products generated by discharge, providing early warning of insulation faults and preventing sudden power outages. However, partial discharge detection equipment requires regular calibration; otherwise, the accuracy of the detection results will be affected.

[0003] Currently, the common calibration method for partial discharge detection equipment involves generating an injection signal using a signal generator, detecting the output signal using the partial discharge detection equipment, and comparing the detected signal with the target signal to determine the calibration result. However, existing partial discharge signal generation methods only support low-voltage laboratory environments, which differ from the high-voltage environment of actual cables, resulting in relatively low calibration accuracy for existing partial discharge detection equipment.

[0004] Therefore, a partial discharge signal generation device is needed that can be connected to actual cables to improve the calibration accuracy of partial discharge detection equipment. Utility Model Content

[0005] In view of this, the present invention provides a power cable partial discharge signal simulation device, the main purpose of which is to solve the problem that the injection signal generated by the current power cable partial discharge signal simulation device cannot be connected with the actual cable.

[0006] To address the aforementioned problems, this application provides a power cable partial discharge signal simulation device, comprising a signal generation module, a digital-to-analog conversion module, a signal conditioning module, and an isolation access module, wherein...

[0007] The output terminal of the signal generation module is electrically connected to the input terminal of the digital-to-analog converter module, the output terminal of the digital-to-analog converter module is electrically connected to the input terminal of the signal conditioning module, the output terminal of the signal conditioning module is electrically connected to the input terminal of the isolation access module, and the output terminal of the isolation access module is electrically connected to the cable connector.

[0008] In one embodiment of this utility model, optionally, the signal conditioning module includes an RC filter unit, an amplification unit, and an LC filter unit. The input terminal of the RC filter unit is electrically connected to the output terminal of the digital-to-analog conversion module, the output terminal of the RC filter unit is electrically connected to the input terminal of the amplification unit, the output terminal of the amplification unit is electrically connected to the input terminal of the LC filter unit, and the output terminal of the LC filter unit is electrically connected to the isolation access module.

[0009] In one embodiment of this utility model, optionally, the power cable partial discharge signal simulation device further includes a power supply module, and the isolation access module includes an isolation interface and a current transformer. The first end of the isolation interface is electrically connected to the output end of the LC filter unit, the second end of the isolation interface is electrically connected to the first end of the primary side of the current transformer, the second end of the primary side of the current transformer is electrically connected to the negative terminal of the power supply module, the first end of the secondary side of the current transformer is electrically connected to the cable connector, and the second end of the secondary side of the current transformer is electrically connected to the cable grounding terminal.

[0010] In one embodiment of this utility model, optionally, the power cable partial discharge signal simulation device further includes a feedback calibration module, wherein the feedback calibration module is a current sensor, and the output terminal of the current sensor is electrically connected to the feedback signal input terminal of the signal generation module.

[0011] In one embodiment of this utility model, optionally, the current sensor is sleeved on the line between the first end of the secondary side of the current transformer and the cable connector.

[0012] In one embodiment of the present invention, optionally, the signal generation module modifies the output partial discharge simulation signal based on the comparison result between the feedback signal transmitted by the feedback calibration module and the target signal.

[0013] In one embodiment of the present invention, the power cable partial discharge signal simulation device may optionally include an interaction module, which is electrically connected to the signal generation module via serial communication.

[0014] In one embodiment of this utility model, optionally, the signal generation module and the digital-to-analog conversion module are connected via serial communication.

[0015] The beneficial effects of this application are as follows: The power cable partial discharge signal simulation device provided by this utility model generates a partial discharge simulation signal through a signal generation module, transmits the partial discharge simulation signal to a digital-to-analog conversion module, converts the partial discharge simulation signal from a digital signal to an analog signal, and amplifies and filters the analog signal through a signal conditioning signal. The amplified and filtered analog signal is then connected to the actual high-voltage cable through an isolation access module, thereby realizing the injection of the partial discharge simulation signal into the actual high-voltage cable and improving the calibration accuracy of the partial discharge detection equipment.

[0016] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of a power cable partial discharge signal simulation device, which is an exemplary embodiment of the present invention.

[0019] Figure 2 A structural connection diagram of the signal conditioning module of the power cable partial discharge signal simulation device, which is an exemplary embodiment of this utility model;

[0020] Figure 3 A structural connection diagram of the isolation access module of the power cable partial discharge signal simulation device, which is an exemplary embodiment of this utility model;

[0021] Figure 4 A structural connection diagram of the signal generation module of the power cable partial discharge signal simulation device, which is an exemplary embodiment of this utility model;

[0022] Figures 1-3 In the diagram, 1-Signal generation module; 2-Digital-to-analog conversion module; 3-Signal conditioning module; 4-Isolation access module; 5-Cable connector; 6-Interaction module; 31-RC filter unit; 32-Amplification unit; 33-LC filter unit; 41-Isolation interface; 42-Current transformer; 43-Current sensor. Detailed Implementation

[0023] To overcome the deficiencies in the prior art, this utility model provides a power cable partial discharge signal simulation device. To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the preferred embodiments of this utility model will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this utility model. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. The embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0024] This application provides a device for simulating partial discharge signals in power cables, see [link]. Figure 1 It includes a signal generation module 1, a digital-to-analog conversion module 2, a signal conditioning module 3, and an isolation access module 4, wherein...

[0025] The output of signal generation module 1 is electrically connected to the input of digital-to-analog converter module 2. The output of digital-to-analog converter module 2 is electrically connected to the input of signal conditioning module 3. The output of signal conditioning module 3 is electrically connected to the input of isolation access module 4. The output of isolation access module 4 is electrically connected to cable connector 5.

[0026] Specifically, the signal generation module retrieves a partial discharge waveform template (such as surface discharge or air gap discharge lamp) from its internal data storage unit, generates noise (with adjustable signal-to-noise ratio) through a noise injection unit, and then superimposes the retrieved waveform signal with the noise through a waveform generation unit to obtain a partial discharge simulation signal. The signal generation module can be implemented using an FPGA. The signal generation module outputs the partial discharge simulation signal to a high-speed digital-to-analog converter module via the JESD204B protocol.

[0027] The high-speed digital-to-analog converter module converts digital signals into high-fidelity, high-precision analog signals and transmits them to the signal conditioning module. The signal conditioning module amplifies and filters the signal to suppress high-frequency noise and then transmits the conditioned analog signal to the high-voltage side. The signal is then injected into the high-voltage cable through the isolation access module to achieve electrical isolation between the low-voltage side and the high-voltage cable. The module also safely injects the cable partial discharge simulation signal into the operating cable to simulate a real discharge scenario.

[0028] It should be noted that the signal generation module calls the corresponding waveform template, superimposes adjustable noise, and generates a partial discharge simulation signal through existing technology. The generation of the partial discharge simulation signal by the signal generation module is an existing technology.

[0029] Compared with the prior art, the power cable partial discharge signal simulation device provided by this utility model generates a partial discharge simulation signal through a signal generation module, transmits the partial discharge simulation signal to a digital-to-analog conversion module, converts the partial discharge simulation signal from a digital signal to an analog injection signal, and amplifies and filters the analog injection signal through a signal conditioning module. The amplified and filtered injection signal is then connected to the actual high-voltage cable through an isolation access module, thereby realizing the injection of the partial discharge simulation signal into the actual high-voltage cable and improving the calibration accuracy of the partial discharge detection equipment.

[0030] In one embodiment of this utility model, see Figure 2 The signal conditioning module 3 includes an RC filter unit 31, an amplification unit 32, and an LC filter unit 33. The input terminal of the RC filter unit 31 is electrically connected to the output terminal of the digital-to-analog converter module 2. The output terminal of the RC filter unit 31 is electrically connected to the input terminal of the amplification unit 32. The output terminal of the amplification unit 32 is electrically connected to the input terminal of the LC filter unit 33. The output terminal of the LC filter unit 33 is electrically connected to the isolation access module 4.

[0031] In this embodiment, the analog signal output by the digital-to-analog converter module is filtered by the combination of capacitors and resistors in the RC filter unit to suppress high-frequency noise, and then output to the programmable gain amplifier unit. The programmable gain amplifier unit sets the amplification factor according to the actual application to amplify the analog signal. The signal output by the amplifier unit is filtered by the combination of inductors and capacitors in the LC filter unit for anti-aliasing, and then output to the high-voltage isolation interface.

[0032] In one embodiment of this utility model, see Figure 3 The power cable partial discharge signal simulation device also includes a power supply module. The isolation access module 4 includes an isolation interface 41 and a current transformer 42. The first end of the isolation interface 41 is electrically connected to the output end of the LC filter unit 33. The second end of the isolation interface 41 is electrically connected to the first end of the primary side of the current transformer 42. The second end of the primary side of the current transformer 42 is electrically connected to the negative terminal of the power supply module. The first end of the secondary side of the current transformer 42 is electrically connected to the cable connector. The second end of the secondary side of the current transformer 42 is electrically connected to the cable grounding terminal.

[0033] In this embodiment, the isolation interface itself includes isolation elements (such as optocouplers, magnetic isolators, etc.) to further achieve electrical isolation of the signal, ensuring safe isolation between the low-voltage side (signal generation circuit) and the high-voltage side (cable system), and preventing interference or damage from the high-voltage side to the low-voltage side circuit. An analog signal (after LC filtering and the isolation interface) flows through the primary side of the current transformer, generating an alternating magnetic field. When an alternating current flows through the primary side of the current transformer, a corresponding current signal (i.e., a partial discharge simulation signal) is induced on the secondary side of the current transformer. This signal flows into the cable body through the cable connector, forming a loop with the cable grounding terminal, effectively simulating a real partial discharge current in the cable system.

[0034] In one embodiment of this utility model, see Figure 3 The power cable partial discharge signal simulation device also includes a feedback calibration module, which is a current sensor 43. The output terminal of the current sensor 43 is electrically connected to the feedback signal input terminal of the signal generation module 1. The current sensor 43 is mounted on the line between the first end of the secondary side of the current transformer 42 and the cable connector.

[0035] In one embodiment of this utility model, the signal generation module 1 modifies the output partial discharge simulation signal based on the comparison result between the feedback signal transmitted by the feedback calibration module and the target signal.

[0036] In this embodiment, the feedback calibration module collects the signal from the actual high-voltage cable and sends it to the signal generation module. The signal generation module dynamically compensates for amplitude attenuation and phase deviation, and adjusts the output waveform to ensure accuracy.

[0037] On the high-voltage side, a current sensor monitors the output current and transmits the current value to the signal generation module. The signal generation module compares the data sampled by the current sensor with the expected waveform, calculates the amplitude error and phase deviation, and modifies the data transmitted to the digital-to-analog converter module in real time.

[0038] In one embodiment of this utility model, the power cable partial discharge signal simulation device further includes an interaction module 6, which is electrically connected to the signal generation module 1 via serial communication.

[0039] In this embodiment, see Figure 4 As shown, the user interacts with the signal generation module 1 via the UART serial communication interface through the interaction module 6. For example, the user configures the signal (such as discharge type and frequency setting) and returns the system status (such as signal amplitude and calibration progress) through the interaction module 6; the user sets parameters such as discharge type (such as corona discharge), amplitude (5V), and frequency (100MHz) through the interaction module 6.

[0040] In one embodiment of this utility model, the signal generation module 1 and the digital-to-analog conversion module 2 are connected via serial communication.

[0041] In this embodiment, the signal generation module typically transmits signals to the digital-to-analog converter module via a serial communication interface, such as through LVDS or JESD204B communication. JESD204B communication is preferred because it has a faster transmission rate and requires fewer wires than LVDS.

[0042] In one embodiment, the partial discharge detection device is calibrated using a 10kV cable as an example. The "surface discharge" mode is selected via the interactive module, and the pulse amplitude is set to 5V and the repetition rate to 100Hz. The signal is injected into the shielding layer of the 10kV cable connector through a high-voltage isolation interface. The feedback calibration module collects the signal and feeds it back to the signal generation module, automatically compensating for attenuation caused by cable impedance.

[0043] Use partial discharge detection equipment to test the cable, confirm that the set signal has been detected, and complete the calibration of the detection equipment.

[0044] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0045] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0046] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0047] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application.

[0048] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0049] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0050] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0051] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A device for simulating partial discharge signals in power cables, characterized in that, include: The signal generation module, digital-to-analog conversion module, signal conditioning module, and isolation access module are included. The output terminal of the signal generation module is electrically connected to the input terminal of the digital-to-analog converter module, the output terminal of the digital-to-analog converter module is electrically connected to the input terminal of the signal conditioning module, the output terminal of the signal conditioning module is electrically connected to the input terminal of the isolation access module, and the output terminal of the isolation access module is electrically connected to the cable connector. The signal generation module is an FPGA chip. The signal conditioning module includes an RC filter unit, an amplification unit, and an LC filter unit. The power cable partial discharge signal simulation device also includes a power supply module. The isolation access module includes an isolation interface and a current transformer. The first end of the isolation interface is electrically connected to the output end of the LC filter unit. The second end of the isolation interface is electrically connected to the first end of the primary side of the current transformer. The second end of the primary side of the current transformer is electrically connected to the negative terminal of the power supply module. The first end of the secondary side of the current transformer is electrically connected to the cable connector. The second end of the secondary side of the current transformer is electrically connected to the cable grounding terminal.

2. The power cable partial discharge signal simulation device according to claim 1, characterized in that, The input terminal of the RC filter unit is electrically connected to the output terminal of the digital-to-analog converter module, the output terminal of the RC filter unit is electrically connected to the input terminal of the amplifier unit, the output terminal of the amplifier unit is electrically connected to the input terminal of the LC filter unit, and the output terminal of the LC filter unit is electrically connected to the isolation access module.

3. The power cable partial discharge signal simulation device according to claim 1, characterized in that, The power cable partial discharge signal simulation device also includes a feedback calibration module, which is a current sensor. The output terminal of the current sensor is electrically connected to the feedback signal input terminal of the signal generation module.

4. The power cable partial discharge signal simulation device according to claim 3, characterized in that, The current sensor is mounted on the line between the first end of the secondary side of the current transformer and the cable connector.

5. The power cable partial discharge signal simulation device according to claim 3, characterized in that, The signal generation module modifies the output partial discharge simulation signal based on the comparison result between the feedback signal transmitted by the feedback calibration module and the target signal.

6. The power cable partial discharge signal simulation device according to any one of claims 1-4, characterized in that, The power cable partial discharge signal simulation device also includes an interaction module, which is electrically connected to the signal generation module via serial communication.

7. The power cable partial discharge signal simulation device according to any one of claims 1-4, characterized in that, The signal generation module and the digital-to-analog conversion module are connected via serial communication.

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