Ground insulation double-end detection system for mining high-voltage cable

Abstract

The utility model relates to the technical field of high-voltage power cable insulation on-line monitoring, and especially relates to a mining high-voltage cable ground insulation double-end detection system. Comprising at least two voltage transformers and at least one high-frequency current sensor, wherein the voltage transformers are arranged on a measured cable and used for measuring voltages at two ends of the measured cable; the high-frequency current sensor is used for measuring high-frequency current components in current of the measured cable; the detection unit is composed of at least two line current transformers used for measuring leakage current signals in the detected cable and at least one zero-sequence current transformer used for measuring zero-sequence current in the detected cable; and a high-speed synchronous acquisition unit, an MCU controller, a communication conditioning unit and a server. According to the utility model, the high-speed synchronous acquisition unit acquires signals of the voltage transformer, the high-frequency current sensor, the line current transformer and the zero-sequence current transformer which are arranged on the tested cable, and the MCU controller analyzes and processes the acquired data, so that the insulation state of each tested cable can be accurately judged.

Description

Technical Field

[0001] This utility model relates to the field of online monitoring technology for insulation of high-voltage power cables, and in particular to a dual-end detection system for the insulation of high-voltage cables to ground in mining applications. Background Technology

[0002] Ground insulation testing technology plays a crucial role in power systems and electrical equipment, especially in ensuring safe operation and preventing electrical faults. Existing ground insulation testing methods mainly include DC voltage testing, insulation resistance and polarization index (PI) testing, and partial discharge (PD) detection. These methods are widely used in the maintenance and testing of power equipment. However, with the increasing complexity of power systems, these traditional technologies have shown significant limitations in certain scenarios.

[0003] Currently, insulation testing has limited real-time performance and sensitivity, making it difficult to handle transient faults or rapid changes. Furthermore, existing testing systems cannot achieve distributed installation, hindering rapid and flexible networking and communication. Utility Model Content

[0004] To solve at least one of the above-mentioned technical problems, this utility model proposes a double-end detection system for the insulation of high-voltage cables to ground in mining applications. The system uses a high-speed synchronous acquisition unit to collect signals from voltage transformers, high-frequency current sensors, line current transformers, and zero-sequence current transformers installed on the cable under test. The collected data is then analyzed and processed by an MCU controller to accurately determine the insulation status of the cable under test at each location.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A dual-end detection system for the insulation of high-voltage cables used in mining, comprising:

[0007] The detection unit includes at least two voltage transformers installed on the cable under test for measuring the voltage across the two ends of the cable under test, at least one high-frequency current sensor for measuring the high-frequency current component in the current of the cable under test, at least two line current transformers for measuring the leakage current signal in the cable under test, and at least one zero-sequence current transformer for measuring the zero-sequence current in the cable under test.

[0008] A high-speed synchronous acquisition unit is used to acquire signals from a voltage transformer, a high-frequency current sensor, a line current transformer, and a zero-sequence current transformer. The voltage transformer, the high-frequency current sensor, the line current transformer, and the zero-sequence current transformer are electrically connected to the high-speed synchronous acquisition unit.

[0009] An MCU controller is electrically connected to the high-speed synchronous acquisition unit, and the MCU controller is used to receive and process the data acquired by the high-speed synchronous acquisition unit;

[0010] A communication conditioning unit is electrically connected to the MCU controller, and the communication conditioning unit is used to transmit the data processed by the MCU controller to the server via GPS;

[0011] The server is electrically connected to the communication conditioning unit. The server displays the insulation status of the measured cable, provides alarms for abnormal insulation data, and manages and stores the insulation data.

[0012] Preferably, the zero-sequence current transformer is sleeved at a position 50-100mm from the middle of the joint of the cable under test, the line current transformer is sleeved on a single phase line of the cable under test and installed in the distribution cabinet, the voltage transformer is connected in parallel on both sides of the cable under test, and the high-frequency current sensor is installed at the beginning or end of the cable under test and sleeved on the grounding shield of the cable.

[0013] Preferably, the high-speed synchronous acquisition unit includes an optical fiber interface module, an analog front-end module, a clock management module, an ADC module, an FPGA module, and an onboard high-capacity DRAM module.

[0014] The optical fiber interface module is used for optical fiber communication with external devices and converts optical fiber signals into electrical signals before transmitting them to other modules; the analog front-end module is used for amplifying, filtering, and sampling input signals; the clock management module is used for generating and managing the clock signals required by each module; the ADC module is used to receive signals from the analog front-end module and convert them into digital signals; the FPGA module is used to receive digital signals from the ADC module and perform data processing and analysis according to predetermined algorithms and logic; and the onboard high-capacity DRAM module is used to store and cache the acquired data.

[0015] Preferably, the communication conditioning unit includes an FFD module, a microprocessor module, an external power supply module, and a GPS communication module;

[0016] The FFD module is used to communicate with other devices and is electrically connected to the microprocessor module, the external power supply module, and the GPS communication module. The microprocessor module is used to process and control the communication process and is electrically connected to the FFD module, the external power supply module, and the GPS communication module. The external power supply module is used to provide power and is electrically connected to the microprocessor module and the FFD module. The GPS module is used to communicate with GPS to obtain current location and time information and is electrically connected to the microprocessor module and the FFD module.

[0017] Preferably, the GPS communication adopts the NMEA0183V3.0 / UBX protocol, 2.4G physical layer.

[0018] Preferably, the server is connected to a display screen and an alarm device.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention uses a high-speed synchronous acquisition unit to collect signals from voltage transformers, high-frequency current sensors, line current transformers, and zero-sequence current transformers installed on the cable under test. The acquired data is then analyzed and processed by an MCU controller to accurately determine the insulation status of the cable at each point. The system has a simple structure, facilitating distributed installation. The high-speed synchronous acquisition unit can also function as a communication router, enabling rapid and flexible networking and communication. Furthermore, the system possesses strong anti-interference capabilities, improving the accuracy of insulation detection. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a double-end detection system for the insulation of high-voltage cables used in mining.

[0022] Figure 2 is a flowchart of the insulation judgment process of this utility model;

[0023] Figure 2a For ΔI j Flowchart of the algorithm for the phase relationship with the three-phase ground voltage;

[0024] Figure 2b Here is a flowchart of the two-phase insulation degradation algorithm;

[0025] In the diagram: 1. Voltage transformer; 2. Line current transformer; 3. Zero-sequence current transformer; 4. Cable under test; 5. High-frequency current sensor. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions in this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments in this utility model, and not all of the embodiments in this utility model.

[0027] Please refer to Figure 1 As shown, the dual-end detection system for the insulation of high-voltage cables to ground in mining applications includes:

[0028] The detection unit includes at least two voltage transformers 1 installed on the cable under test 4 for measuring the voltage across the two ends of the cable under test 4, at least one high-frequency current sensor 5 for measuring the high-frequency current component in the current of the cable under test 4, at least two line current transformers 2 for measuring the leakage current signal in the cable under test 4, and at least one zero-sequence current transformer 3 for measuring the zero-sequence current in the cable under test 4.

[0029] The high-speed synchronous acquisition unit is used to acquire signals from voltage transformer 1, high-frequency current sensor 5, line current transformer 2 and zero-sequence current transformer 3. Voltage transformer 1, high-frequency current sensor 5, line current transformer 2 and zero-sequence current transformer 3 are electrically connected to the high-speed synchronous acquisition unit respectively.

[0030] The MCU controller is electrically connected to the high-speed synchronous acquisition unit and is used to receive and process the data acquired by the high-speed synchronous acquisition unit.

[0031] The communication conditioning unit is electrically connected to the MCU controller and is used to transmit the data processed by the MCU controller to the server via GPS.

[0032] The server is electrically connected to the communication conditioning unit. The server displays the insulation status of the measured cable, provides alarms for insulation data anomalies, and manages and stores the insulation data.

[0033] The above embodiment uses a high-speed synchronous acquisition unit to collect signals from the voltage transformer 1, high-frequency current sensor 5, line current transformer 2, and zero-sequence current transformer 3 installed on the cable under test 4. The collected data is then analyzed and processed by an MCU controller to accurately determine the insulation status of the cable under test 4 at each location. This system has a simple structure, facilitating distributed installation. The high-speed synchronous acquisition unit can also function as a communication router, enabling rapid and flexible networking and communication. Furthermore, this system has strong anti-interference capabilities, improving the accuracy of insulation detection.

[0034] It should be noted that in this embodiment, the zero-sequence current transformer 3 is installed 50-100mm away from the middle of the joint of the cable under test 4, and the line current transformer 2 is installed in the distribution cabinet where the cable 4 is connected. The zero-sequence current transformer 3 is installed on the three phase wires of the cable under test 4 to form a three-wire connection; the line current transformer 2 is installed on a single phase wire of the cable under test 4 in the distribution cabinet to form a single-wire connection; the voltage transformer 1 is connected in parallel on both sides of the cable under test 4 to form a parallel connection; the high-frequency current sensor 5 is installed at the beginning or end of the cable under test 4 and is installed on the grounding shield wire of the cable 4.

[0035] In one embodiment, the high-speed synchronous acquisition unit described above includes an optical fiber interface module, an analog front-end module, a clock management module, an ADC module, an FPGA module, and an onboard high-capacity DRAM module.

[0036] The fiber optic interface module is used for fiber optic communication with external devices and converts fiber optic signals into electrical signals before transmitting them to other modules. The fiber optic interface module typically uses photoelectric converters and fiber optic transceivers to achieve photoelectric conversion and fiber optic communication.

[0037] The analog front-end module is used to amplify, filter, and sample input signals. It typically includes analog signal processing circuitry, such as amplifiers, filters, and sampling circuits. The analog front-end module converts the acquired analog signals into digital signals and passes them to other modules for further processing.

[0038] The clock management module generates and manages the clock signals required by each module. It typically includes a clock generator and clock distribution circuitry. The clock management module ensures the timing synchronization and stability of each module, guaranteeing the accuracy and reliability of data acquisition and processing.

[0039] An ADC module receives signals from an analog front-end module and converts them into digital signals for subsequent digital signal processing. The performance of the ADC module (such as resolution and sampling rate) has a significant impact on the accuracy and speed of data acquisition.

[0040] An FPGA module is a programmable hardware platform used to implement various data processing algorithms and logic functions. It receives digital signals from the ADC module and performs data processing and analysis according to predetermined algorithms and logic. FPGA modules offer high flexibility and programmability, allowing for customized data processing based on specific needs.

[0041] The onboard high-capacity DRAM module is used to store and cache the acquired data to enable high-speed data reading, writing and transmission.

[0042] In one embodiment, the communication conditioning unit includes an FFD module, a microprocessor module, an external power supply module, and a GPS communication module;

[0043] The FFD (Full Function Device) module is a fully functional device responsible for communicating with other devices. It acts as the master device, coordinating and managing the communication process. The FFD module is connected to the microprocessor module, external power supply module, and GPS communication module via circuitry.

[0044] The processor module is the core of the communication conditioning unit, responsible for processing and controlling the communication process. It can execute various communication protocols and algorithms to achieve data transmission, parsing, and processing. The microprocessor module is connected to the FFD module, external power supply module, and GPS communication module via circuitry.

[0045] External power supply module: The external power supply module is responsible for providing a stable power supply to the communication conditioning unit. It can receive external power input and connect to the microprocessor module and FFD module through circuitry to supply them with the power they need.

[0046] GPS Communication Module: The GPS communication module is responsible for communicating with the GPS system to obtain current location and time information. It can receive GPS signals and is connected to the microprocessor module and FFD module via circuitry. The data from the GPS communication module can be used for applications such as positioning and time synchronization. The GPS communication can adopt the NMEA0183V3.0 / UBX protocol, 2.4G physical layer.

[0047] It should be noted that the modules included in the high-speed synchronous acquisition unit and communication conditioning unit can be added or removed according to actual needs during actual operation, and the functional principles of the corresponding modules can be understood as existing technologies.

[0048] like Figure 2a and Figure 2b As shown, in this embodiment, the decision tree algorithm is used to process the relevant data of the cable under test 4. Specifically, the relationship between voltage and zero-sequence current of the symmetrical insulation circuit is different from that of the asymmetrical insulation circuit. Therefore, the insulation conductance and distributed capacitance values ​​calculated are also different, which can realize the classification and identification of the insulation status of the cable under test 4.

[0049] First, the insulation condition of the cable under test 4 is divided into two categories: symmetrical insulation and asymmetrical insulation. Second, the symmetrical insulation category is further divided into two cases: normal insulation and symmetrical insulation degradation, and the asymmetrical insulation category is divided into single-phase insulation degradation and two-phase insulation degradation.

[0050] Before determining the insulation state of the cable under test 4, it is assumed that the insulation of all lines of the cable under test 4 is symmetrical and satisfies the equation. If the insulation of the four lines of the cable under test is symmetrical, the assumption holds, and the conductivity and distributed capacitance of the four lines can be calculated. Based on the conductivity value, it can be determined whether the cable insulation is in a good or symmetrically deteriorated state. Conversely, if the insulation of the four lines of the cable under test is asymmetrical, the assumption does not hold, meaning the actual zero-sequence equivalent circuit relationship of the line is not satisfied. In this case, the calculated conductivity and distributed capacitance values ​​will be negative, indicating that the insulation of the line is asymmetrical. Because the types of deteriorated phases of the insulated cable under various conditions are considered, the measurement accuracy is high, the anti-interference ability is strong, and the reliability is high.

[0051] Of course, the above is just one example of a method for judging insulation status. Those skilled in the art can also use existing methods to judge the insulation status of the cable under test 4. This application will not elaborate further here.

[0052] To facilitate operators in intuitively obtaining the insulation status of the cable 4 under test, in this embodiment, the server is connected to a display screen and an alarm device.

[0053] This invention uses a high-speed synchronous acquisition unit to collect signals from voltage transformers, high-frequency current sensors, line current transformers, and zero-sequence current transformers installed on the cable under test. The acquired data is then analyzed and processed by an MCU controller to accurately determine the insulation status of the cable at each point. The system has a simple structure, facilitating distributed installation. The high-speed synchronous acquisition unit can also function as a communication router, enabling rapid and flexible networking and communication. Furthermore, the system possesses strong anti-interference capabilities, improving the accuracy of insulation detection.

[0054] The above description is a specific implementation of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A double-end detection system for the insulation of high-voltage cables to ground in mining applications, characterized in that, include: The detection unit includes at least two voltage transformers (1) installed on the cable under test (4) for measuring the voltage at both ends of the cable under test (4), at least one high-frequency current sensor (5) for measuring the high-frequency current component in the current of the cable under test (4), at least two line current transformers (2) for measuring the leakage current signal in the cable under test (4), and at least one zero-sequence current transformer (3) for measuring the zero-sequence current in the cable under test (4). The zero-sequence current transformer (3) is installed 50-100mm away from the middle of the joint of the cable under test (4), the line current transformer (2) is installed on a single phase line of the cable under test (4) and installed in the distribution cabinet, the voltage transformer (1) is connected in parallel on both sides of the cable under test (4), and the high-frequency current sensor (5) is installed at the beginning or end of the cable under test (4) and installed on the grounding shield wire of the cable under test (4). A high-speed synchronous acquisition unit is used to acquire signals from a voltage transformer (1), a high-frequency current sensor (5), a line current transformer (2), and a zero-sequence current transformer (3). The voltage transformer (1), the high-frequency current sensor (5), the line current transformer (2), and the zero-sequence current transformer (3) are electrically connected to the high-speed synchronous acquisition unit. An MCU controller is electrically connected to the high-speed synchronous acquisition unit, and the MCU controller is used to receive and process the data acquired by the high-speed synchronous acquisition unit; A communication conditioning unit is electrically connected to the MCU controller, and the communication conditioning unit is used to transmit the data processed by the MCU controller to the server via GPS; The server is electrically connected to the communication conditioning unit. The server displays the insulation status of the measured cable, provides alarms for abnormal insulation data, and manages and stores the insulation data.

2. The double-end detection system for the insulation of mining high-voltage cables to ground according to claim 1, characterized in that, The high-speed synchronous acquisition unit includes an optical fiber interface module, an analog front-end module, a clock management module, an ADC module, an FPGA module, and an onboard high-capacity DRAM module. The optical fiber interface module is used for optical fiber communication with external devices and converts optical fiber signals into electrical signals before transmitting them to other modules; the analog front-end module is used for amplifying, filtering, and sampling input signals; the clock management module is used for generating and managing the clock signals required by each module; the ADC module is used to receive signals from the analog front-end module and convert them into digital signals; the FPGA module is used to receive digital signals from the ADC module and perform data processing and analysis according to predetermined algorithms and logic; and the onboard high-capacity DRAM module is used to store and cache the acquired data.

3. The double-end detection system for the insulation of mining high-voltage cables to ground according to claim 1, characterized in that, The communication conditioning unit includes an FFD module, a microprocessor module, an external power supply module, and a GPS communication module; The FFD module is used to communicate with other devices and is electrically connected to the microprocessor module, the external power supply module, and the GPS communication module. The microprocessor module is used to process and control the communication process and is electrically connected to the FFD module, the external power supply module, and the GPS communication module. The external power supply module is used to provide power and is electrically connected to the microprocessor module and the FFD module. The GPS module is used to communicate with GPS to obtain current location and time information and is electrically connected to the microprocessor module and the FFD module.

4. The double-end detection system for ground insulation of mining high-voltage cables according to claim 3, characterized in that, The GPS communication uses the NMEA0183V3.0 / UBX protocol, 2.4G physical layer.

5. The double-end detection system for insulation to ground of mining high-voltage cables according to claim 1, characterized in that, The server is connected to a display screen and an alarm device.

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