Mechanical characteristic tester suitable for 10KV ring main unit

Abstract

The invention provides a mechanical characteristic tester suitable for a 10kV ring main unit. The mechanical characteristic tester comprises a power supply unit, a data processing unit, a display unit, a voltage and current acquisition unit and a sensor unit, the equipment supplies power to each functional unit through the power supply unit, and acquires electrical and mechanical parameters in the switching operation process of the ring main unit through the voltage and current acquisition unit and the sensor unit. The tester is connected with the DTU device and monitors the voltage and current of the opening, closing and energy storage loop coil and the angle, displacement and speed of the switch in real time, the data processing unit analyzes the voltage and current, and the angle, displacement and speed of the switch, and the display unit displays a diagnosis result so as to evaluate the mechanical characteristics of the ring main unit.

Description

Technical Field

[0001] The invention relates to the technical field of ring network cabinets, and in particular to a mechanical property tester suitable for a 10KV ring network cabinet. Background Art

[0002] 10kV ring main unit is a key switchgear for the power supply of the distribution network ring main unit and the terminal power supply. It is mainly used to break the short-circuit current when the line fails and to switch the load current during daily maintenance work, playing a control and protection role, and effectively improving the power supply reliability and safety of the power grid. Mechanical failures and defects caused by mechanical life, component wear and other problems in the ring main unit account for a considerable proportion, so the detection of the mechanical characteristics of the ring main unit is very important.

[0003] Although the existing mechanical characteristic tester can test the parameters such as the circuit breaker opening and closing time, travel, and bounce speed, the wiring needs to be connected to the switch moving and static contacts. Since the switch equipment is installed in a closed ring network cabinet, the switch moving and static contacts are not exposed, so the existing mechanical characteristic tester cannot be directly used. In addition, most of the existing mechanical characteristic testers do not have diagnostic analysis functions, and the operation and maintenance personnel need to analyze the test results based on experience. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a mechanical property tester suitable for a 10KV ring main unit, so as to realize efficient mechanical property detection of the 10KV ring main unit.

[0005] In order to solve the above technical problems, the present invention provides a mechanical property tester suitable for 10KV ring main unit, comprising a power supply unit, a data processing unit, a display unit, a voltage and current acquisition unit and a sensor unit;

[0006] The power supply unit is used to supply power to the data processing unit, the display unit, the voltage and current acquisition unit and the sensor unit;

[0007] The voltage and current acquisition unit is connected to the opening and closing outlet cables, the closing outlet cables and the energy storage outlet cables of the DTU device, and is used to collect the voltage and current of the opening circuit coil, the closing circuit coil and the energy storage circuit coil of the ring network cabinet; the DTU device is connected to the opening circuit, the closing circuit and the energy storage circuit of the ring network cabinet through the opening and closing outlet cables, the closing outlet cables and the energy storage cables respectively;

[0008] The sensor unit is connected to the switch operating mechanism of the ring main unit and is used to detect the angle, displacement and speed of the switch during the opening and closing process;

[0009] The data processing unit is used to diagnose and analyze the mechanical characteristics of the ring network cabinet according to the voltage and current of the opening circuit coil, the closing circuit coil and the energy storage circuit coil, and the angle, displacement and speed of the switch during the opening and closing process, and display them.

[0010] The present invention has the following beneficial effects:

[0011] The present invention collects the voltage and current of the loop coil related to the ring network cabinet by connecting the outlet cable of the DTU device, without directly contacting the moving and static contacts of the switch, and realizes the non-invasive mechanical property detection of the switch device inside the closed ring network cabinet, reducing the difficulty and risk of operation. The present invention adopts the sensor unit to monitor the key parameters such as the angle, displacement and speed of the switch in real time, and can quickly and accurately obtain the mechanical property data of the ring network cabinet, thereby improving the detection efficiency. The present invention is equipped with a data processing unit, which can comprehensively analyze the collected data such as voltage, current, angle, displacement and speed, realize the diagnosis and analysis of the mechanical characteristics of the ring network cabinet, and help to find potential faults and defects. Through the detection and analysis of the mechanical characteristics of the ring network cabinet by the present invention, the mechanical faults and defects of the ring network cabinet can be discovered and handled in time, and the power supply reliability and safety of the power grid can be effectively improved. The data processing and display functions provided by the present invention enable the operation and maintenance personnel to intuitively understand the operating status of the ring network cabinet, which helps the operation and maintenance personnel to make fault analysis and maintenance decisions based on experience. Compared with the traditional mechanical property testing method, the present invention does not need to disassemble the ring network cabinet, reduces the investment of manpower and material resources, and reduces the maintenance cost. The present invention is applicable to 10kV ring main unit, has good versatility, and can provide mechanical property detection services for ring main units of different models and specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0013] Figure 1 The structure frame diagram of a mechanical property tester suitable for a 10kV ring main unit in an embodiment of the present invention.

[0014] Figure 2 The figure is a schematic diagram of the connection between a mechanical property tester suitable for a 10kV ring main unit, a DTU device and a ring main unit in an embodiment of the present invention.

[0015] Figure 3The following are appearance diagrams of a mechanical property tester suitable for a 10kV ring main unit in an embodiment of the present invention at three different viewing angles. DETAILED DESCRIPTION

[0016] The detailed description of the drawings is intended as an illustration of the current embodiment of the present application, and is not intended to represent the only form in which the present application can be implemented. It should be understood that the same or equivalent functions can be accomplished by different embodiments intended to be included in the spirit and scope of the present application.

[0017] See also Figures 1-2 An embodiment of the present invention provides a mechanical property tester suitable for a 10kV ring main unit, comprising a power supply unit, a data processing unit, a display unit, a voltage and current acquisition unit, and a sensor unit.

[0018] The power supply unit is used to provide a stable power supply for the entire mechanical properties tester. The power supply unit may include an AC-DC converter, a battery pack or other power management system to ensure that the data processing unit, display unit, voltage and current acquisition unit and sensor unit can work normally.

[0019] The voltage and current acquisition unit is connected to the opening outlet cable, closing outlet cable and energy storage outlet cable of the DTU device, and is used to collect the voltage and current of the opening circuit coil, closing circuit coil and energy storage circuit coil of the ring network cabinet; the DTU device is respectively connected to the opening circuit, closing circuit and energy storage circuit of the ring network cabinet through the opening outlet cable, closing outlet cable and energy storage cable; by connecting the outlet cables of the DTU device, the voltage and current acquisition unit can non-invasively monitor the operating current and voltage of the ring network cabinet. These data reflect the electrical characteristics of the coil during operation and are important parameters for analyzing mechanical characteristics.

[0020] Among them, in high-voltage switchgear such as ring main units, the opening circuit coil, closing circuit coil and energy storage circuit coil are important electromagnetic components, each of which has different functions.

[0021] The opening circuit coil is used to drive the switch from the closed state (closing state) to the open state (opening state); when the opening command is issued, the opening coil is energized to generate a magnetic field, driving the tripping mechanism of the switch, thereby disconnecting the switch and cutting off the circuit; the opening coil is usually designed with a higher instantaneous starting current to generate sufficient force to quickly disconnect the circuit;

[0022] The function of the closing circuit coil is opposite to that of the opening coil. It is used to drive the switch from the open state to the closed state. When the closing command is issued, the closing coil is energized, and the generated magnetic field drives the closing mechanism of the switch to close the switch and connect the circuit. The closing coil also needs sufficient force to ensure that the switch can be closed reliably, but usually its current and magnetic field strength are designed to be slightly smaller than those of the opening coil.

[0023] The main function of the energy storage loop coil is to store energy before the switch is opened or closed. Before the operation, the energy storage coil is energized to store energy in the energy storage mechanism (such as a spring or a heavy hammer). When the opening or closing operation is required, the stored energy is released to drive the switch. The energy storage coil usually requires a longer current supply to store enough energy, but its current intensity is not necessarily greater than that of the opening or closing coil.

[0024] The working principle of these coils is based on electromagnetic induction, that is, when current passes through the coil, a magnetic field is generated around it. The magnetic field interacts with the iron core inside the coil to generate mechanical force, thereby driving the operation of the switch; in high-voltage switchgear such as ring main units, the design and performance of these coils have an important impact on the reliability and life of the switch.

[0025] The sensor unit is connected to the switch of the ring main unit to detect the angle, displacement and speed of the switch during the opening and closing process;

[0026] The data processing unit is used to diagnose and analyze the mechanical characteristics of the ring main unit according to the voltage and current of the opening circuit coil, the closing circuit coil and the energy storage circuit coil, and the angle, displacement and speed of the switch during the opening and closing process, and display them. The results of the analysis by the data processing unit are displayed to the operator in the form of graphics or text. The display unit can be a liquid crystal display (LCD), an organic light emitting diode display (OLED) or other display technology, which can visualize the processed data so that the operator can intuitively understand the mechanical state of the ring main unit.

[0027] The overall workflow of the mechanical properties tester is as follows:

[0028] When the mechanical characteristics of the ring main unit need to be tested, the power supply unit starts to supply power to the entire system; the voltage and current acquisition unit starts to collect voltage and current data of the relevant loop coils of the ring main unit through the cable connected to the DTU device; at the same time, the sensor unit monitors the action of the switch and records parameters such as angle, displacement and speed; the collected data is sent to the data processing unit for processing and analysis; the data processing unit conducts a comprehensive analysis of the data based on the preset diagnostic algorithm to evaluate the mechanical characteristics of the ring main unit; finally, the analysis results are presented to the operator through the display unit for further maintenance and troubleshooting.

[0029] In some embodiments, the voltage and current acquisition unit includes three voltage sensors and three current sensors;

[0030] One end of the three voltage sensors is connected to the opening outlet cable, the closing outlet cable and the energy storage cable, and the other end is connected to the outlet neutral line of the DTU device;

[0031] The three current sensors are all Hall sensors, which clamp the opening outlet cable, the closing outlet cable and the energy storage cable respectively.

[0032] Specifically, the voltage sensor determines the voltage of the opening, closing and energy storage loop coils by measuring the voltage difference between the cable and the neutral line. The Hall current sensor measures the current by sensing the magnetic field generated by the current in the cable. When the current passes through the cable, a magnetic field is generated around it. The Hall sensor detects this magnetic field and outputs a signal proportional to the current. The voltage and current sensors convert the collected analog signals into digital signals, which are then transmitted to the data processing unit for further analysis and processing. The data processing unit diagnoses and analyzes the mechanical characteristics of the ring network cabinet based on the data from the voltage and current sensors, combined with the angle, displacement and speed information collected by the sensor unit. In this way, the voltage and current acquisition unit can non-invasively monitor the key electrical parameters of the ring network cabinet and provide important information for the maintenance and fault diagnosis of the ring network cabinet.

[0033] In some embodiments, the sensor unit includes an angular displacement sensor and a velocity sensor;

[0034] The angle displacement sensor is used to detect the angle and displacement of the switch in the ring main unit in the open, closed and energy storage states;

[0035] The speed sensor is used to detect the speed of the switch in the ring main unit in the open, closed and energy storage states.

[0036] In some embodiments, the data processing unit is used to generate corresponding voltage waveforms and current waveforms based on the voltages and currents of the opening circuit coil, closing circuit coil and energy storage circuit coil, compare the voltage waveforms and current waveforms with the voltage waveforms and current waveforms under normal conditions one by one, and obtain diagnostic results based on the comparison results.

[0037] Specifically, the core function of the data processing unit is to analyze the electrical characteristics of the ring main unit and diagnose the mechanical state of the ring main unit by comparing the voltage and current waveforms during operation with the waveforms in normal state. The data processing unit first receives the voltage and current data of the opening circuit coil, the closing circuit coil and the energy storage circuit coil from the voltage and current acquisition unit. These data are time series data, that is, they record the voltage and current values ​​that change over time. The data processing unit converts these time series data into voltage waveforms and current waveforms, which can intuitively display the changes of voltage and current over time. The voltage and current waveforms during operation are generated, and the data processing unit compares them with the pre-stored voltage and current waveforms in normal state. The waveforms in normal state are recorded under normal working conditions of the ring main unit, and they represent the ideal electrical characteristics of the ring main unit in a fault-free state. The comparison process may include analysis of multiple aspects such as the shape, amplitude, phase, frequency component and duration of the waveform. If the waveform during operation is highly consistent with the normal waveform, this indicates that the mechanical state of the ring main unit is good. If there is a significant difference in the waveform, this may indicate that there is a mechanical fault or abnormality in the ring main unit. For example, the waveform may show unusual spikes, fluctuations or changes in shape, which may be signs of a fault. The data processing unit generates a diagnostic report based on the waveform comparison results, indicating possible problems such as jerky switching, worn contacts, damaged coils, etc.

[0038] In some embodiments, the data processing unit is used to determine the core starting stage based on the current waveform. In the core starting stage, if the real-time current is greater than the normal current and the real-time starting time is shorter than the normal starting time, it is determined that the coil turns are short-circuited; if the real-time current is greater than the normal current and the real-time starting time is longer than the normal starting time, it is determined that the core is stuck; wherein the starting time refers to the time required from the start of the coil being energized to the start of the movement of the core in the coil.

[0039] Specifically, the core startup phase refers to the time point when the core starts to move after the coil is energized. This phase is a critical period for current waveform analysis because it is directly related to whether the electromagnetic action of the coil is normal. The data processing unit can determine the moment when the core starts to move, that is, the beginning of the startup time, by monitoring the changes in the current waveform. Real-time current refers to the current value actually measured during the core startup phase. Normal current refers to the expected current value during the core startup phase under fault-free conditions. This value is usually based on historical data or standard values ​​of the ring main unit under normal working conditions. Real-time startup time refers to the time required from the coil being energized to the core starting to move. Normal startup time refers to the expected time required from the core being energized to the core starting to move under fault-free conditions.

[0040] If the real-time current is greater than the normal current and the real-time start-up time is shorter than the normal start-up time, this indicates that the current in the coil has risen sharply, which may be caused by a short circuit between the coil turns. The short circuit between the turns will cause the effective resistance of the coil to decrease, thereby increasing the current. At the same time, due to the reduced magnetic resistance of the short-circuited part, the iron core will be attracted more quickly, resulting in a shorter start-up time. If the real-time current is greater than the normal current and the real-time start-up time is longer than the normal start-up time, this indicates that although the current has increased, the movement of the iron core has been hindered. The core jamming may be caused by mechanical failures, such as dust, dirt or wear that increase the friction between the iron core and the coil housing, causing the iron core to move slowly, resulting in a longer start-up time. Through this analysis method, the data processing unit can effectively diagnose two common faults of the ring main unit coil: short circuit between the coil turns and core jamming. These diagnostic results are of great significance for timely maintenance and repair of the ring main unit to ensure the stable operation of the power grid.

[0041] In some embodiments, the data processing unit is used to determine the core movement stage based on the electric current waveform. During the core movement stage, if the real-time current increases relative to the normal current, and the time required for the core to move from the beginning to reach the predetermined position is prolonged relative to the normal time, the core is determined to be stuck.

[0042] Specifically, the core movement phase refers to the process from the beginning of the core movement until it reaches the predetermined position. This phase is a key part of the current waveform analysis because it reflects the behavior of the core during the entire movement process. Real-time current refers to the current value actually measured during the core movement phase. Normal current refers to the expected current value during the core movement phase under fault-free conditions. This value is usually based on historical data or standard values ​​of the ring main unit under normal working conditions. Real-time movement time refers to the time required for the core to move from the beginning to the predetermined position. Normal movement time refers to the expected time required for the core to move from the beginning to the predetermined position under fault-free conditions.

[0043] If the real-time current increases relative to the normal current during the core movement stage, and the time required for the core to move from the beginning to the predetermined position is extended relative to the normal time required, this indicates that the core has encountered an obstacle during movement. The causes of core jamming may include increased mechanical friction, component wear, foreign matter intrusion, or insufficient lubrication, all of which can cause the core to move unsmoothly and take longer to reach the predetermined position. The reason for the increase in current is that in order to overcome the additional resistance, the coil needs to generate a greater magnetic force, which causes an increase in the current passing through the coil. Through this analysis method, the data processing unit can effectively identify the fault condition of core jamming. This diagnosis helps to promptly discover and solve potential problems of the ring main unit and prevent more serious faults from occurring, thereby ensuring the stable operation of the power grid and the safety of the equipment.

[0044] In some embodiments, the data processing unit is used to determine the coil core stop stage based on the current waveform. In the core stop stage, if the real-time current waveform drops rapidly or shows abnormal peaks relative to the normal current waveform, it is determined that the coil turns are short-circuited. If the real-time current waveform fluctuates or peaks relative to the normal current waveform, and the real-time current drop speed is inconsistent with the normal current, it is determined that the joint is loose. If the real-time current drop speed is abnormally slow relative to the normal current or the current remains at a high level after stopping, it is determined that the half-shaft is buckled too deeply.

[0045] Specifically, the coil core stop phase refers to the time when the core has completed its movement and reached its final position, at which point the current should begin to drop from the higher value that drives the core to a steady-state value or zero. If the real-time current waveform drops rapidly relative to the normal current waveform or has abnormal spikes during the core stop phase, this may be due to a short circuit between turns inside the coil. A short circuit between turns causes the current to pass through the short-circuited path, causing a rapid change in current, which is reflected as a rapid drop or spike on the current waveform.

[0046] If the real-time current waveform fluctuates or spikes relative to the normal current waveform, and the real-time current drop speed is inconsistent with the normal current, this may be caused by loose joints. Loose joints can cause unstable contact resistance, causing current fluctuations or spikes, and changes in the current drop speed.

[0047] The half shaft is a mechanical component in the ring main unit switch. If the real-time current drop speed is abnormally slow compared to the normal current or the current remains at a high level after stopping, it may be caused by the half shaft being buckled too deep. Buckling the half shaft too deep means that when the core is in the stopped position, there is still a large magnetic resistance, causing the coil to maintain a higher current to keep the core in position, so the current drop speed will be slower or the current will remain high after stopping.

[0048] In some embodiments, the data processing unit is used to analyze the frequency distribution of the voltage waveform by Fourier transform, and if the high-frequency component increases relative to the frequency distribution of the voltage waveform under normal conditions, it is determined that the coil insulation is aged.

[0049] Specifically, the Fourier transform is a mathematical tool used to convert a time domain signal (such as a voltage waveform) into a frequency domain signal, so that the signal's composition and strength at different frequencies can be analyzed. Under normal circumstances, the voltage waveform of the ring main unit coil will have a specific frequency distribution, mainly containing the fundamental wave (the same as the grid frequency) and some lower frequency harmonic components. When the insulation of the coil ages, the performance of the insulation material deteriorates, which may cause more high-frequency components in the voltage waveform. These high-frequency components may be caused by insulation breakdown or partial discharge. Insulation aging may cause partial discharges in the coil during operation, and these discharges appear as high-frequency noise in the voltage waveform. Based on the diagnosis results of insulation aging, preventive maintenance can be performed to replace the aged insulation material and avoid potential failures and downtime.

[0050] In some embodiments,

[0051] The data processing unit is used to determine that the operation is incomplete or there is a mechanical obstruction if the real-time angle of the switch is smaller than the normal angle during the opening and closing process of the switch; specifically, if the real-time angle of the switch is smaller than the angle during normal operation during the switch operation, this may indicate that:

[0052] Incomplete operation: The switch may not be fully opened or closed, which may be caused by insufficient operating force or control signal problems;

[0053] Presence of Mechanical Obstruction: The movement of the switch may be mechanically obstructed, such as foreign objects getting stuck, parts being worn or deformed, etc., which may prevent the switch from reaching the intended position.

[0054] In some embodiments, the data processing unit is used to determine mechanical failure or improper adjustment if the real-time displacement of the switch is less than or exceeds the expected normal displacement during the opening and closing process of the switch;

[0055] Specifically, during the opening and closing process of the switch, the real-time displacement and speed of the switch are monitored to diagnose whether the operation is normal. If the real-time displacement of the switch is insufficient relative to the normal displacement, this may indicate:

[0056] Mechanical failure: such as insufficient spring force, drive mechanism failure or jamming, which causes the switch to fail to reach the predetermined position.

[0057] Improper adjustment: The mechanical adjustment of the switch may be incorrect, for example, the limit stop is not set correctly, resulting in the switch not being able to fully open or close.

[0058] If the real-time displacement of the switch exceeds expected relative to normal displacement, this may indicate:

[0059] Mechanical failure: such as overshoot of the drive mechanism, which may cause excessive movement of the switch or even damage.

[0060] Improper adjustment: If the adjustment force is too large, the switch will exceed the normal operating range.

[0061] The data processing unit is used to determine that the operation is unstable if the real-time speed of the switch is too fast or too slow relative to the normal speed during the opening and closing process of the switch.

[0062] Specifically, during the opening and closing of a switch, if the real-time speed of the switch is too fast relative to the normal speed, this may indicate:

[0063] Jerky operation: The movement of the switch may be too rapid, causing shock and vibration that may cause damage to the device.

[0064] If the real-time speed of the switch is too slow relative to normal speed, this may indicate:

[0065] Jerky operation: The movement of the switch may be hindered by excessive friction or an inefficient drive mechanism, causing the switch to operate slowly.

[0066] Through this monitoring and analysis method, the data processing unit can achieve the following goals:

[0067] Fault Detection: By comparing real-time displacement and velocity with data from normal operation, possible mechanical faults or adjustment problems in switch operation can be detected.

[0068] Operation quality assessment: Evaluate whether the switch operation is smooth, so as to judge the working status and potential risks of the equipment.

[0069] Preventive maintenance: By promptly detecting abnormalities in displacement and speed, preventive maintenance measures can be taken to avoid more serious failures.

[0070] This approach helps ensure the reliability and safety of the ring main unit and reduces downtime caused by improper operation or mechanical failure.

[0071] See also Figure 3 The overall appearance design of the mechanical properties tester is to facilitate operation and use while ensuring the safety and functionality of the equipment. The following is a Figure 3 Description of the mentioned parts:

[0072] Power switch: used to control the power on and off of the mechanical properties tester. The operator can turn the device on or off through this switch.

[0073] Power inlet: The interface for connecting the device to an external power source, usually a standard power jack, used to provide a stable power supply for the tester.

[0074] Ground Screw: Used to ground the equipment to prevent electrical interference and ensure operator safety. Grounding is a very important safety measure when working with high voltage equipment.

[0075] Voltage and current acquisition interface: that is, the interface of the voltage and current acquisition unit in this embodiment, which is used to connect to the voltage signal of the device under test so that the tester can collect and analyze voltage data.

[0076] Sensor acquisition interface: that is, the interface of the sensor unit in this embodiment, which is used to connect various sensors, such as angle displacement sensors and speed sensors, to collect angle, displacement, speed and other data of the switch device during operation.

[0077] Device communication port: An interface used for data communication with other devices (such as computers, printers, or network devices). It may be a USB port, RS-232 port, or other type of communication interface.

[0078] LCD communication port: used to connect to an external LCD display.

[0079] Touch screen (i.e. display unit): provides a user interface, through which operators can input commands, view test results and operate equipment. The touch screen makes operation more intuitive and convenient.

[0080] Carrying handle: Designed on the equipment so that the operator can easily carry or move the tester. This is especially important for field testing and situations where the equipment needs to be moved frequently.

[0081] The overall appearance design takes into account the portability, ease of use and safety of the equipment, ensuring that the mechanical properties tester can be effectively operated and maintained in various environments.

[0082] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A mechanical property tester suitable for 10kV ring main unit, characterized in that: It includes a power supply unit, a data processing unit, a display unit, a voltage and current acquisition unit and a sensor unit; The power supply unit is used to supply power to the data processing unit, the display unit, the voltage and current acquisition unit and the sensor unit; The voltage and current acquisition unit is connected to the opening and closing outlet cables, the closing outlet cables and the energy storage outlet cables of the DTU device, and is used to collect the voltage and current of the opening circuit coil, the closing circuit coil and the energy storage circuit coil of the ring network cabinet; the DTU device is connected to the opening circuit, the closing circuit and the energy storage circuit of the ring network cabinet through the opening and closing outlet cables, the closing outlet cables and the energy storage cables respectively; The sensor unit is connected to the switch operating mechanism of the ring main unit and is used to detect the angle, displacement and speed of the switch during the opening and closing process; The data processing unit is used to diagnose and analyze the mechanical characteristics of the ring network cabinet according to the voltage and current of the opening circuit coil, the closing circuit coil and the energy storage circuit coil, and the angle, displacement and speed of the switch during the opening and closing process, and display them.

2. The device according to claim 1, characterized in that The voltage and current acquisition unit includes three voltage sensors and three current sensors; One end of the three voltage sensors is connected to the opening outlet cable, the closing outlet cable and the energy storage cable, and the other end is connected to the outlet neutral line of the DTU device; The three current sensors are all Hall sensors, which clamp the opening outlet cable, the closing outlet cable and the energy storage cable respectively.

3. The device according to claim 1, characterized in that The sensor unit includes an angle displacement sensor and a speed sensor; The angle displacement sensor is used to detect the angle and displacement of the switch in the ring main unit in the open, closed and energy storage states; The speed sensor is used to detect the speed of the switch in the ring main unit in the open, closed and energy storage states.

4. The device according to claim 1, characterized in that The data processing unit is used to generate corresponding voltage waveforms and current waveforms according to the voltages and currents of the opening circuit coil, closing circuit coil and energy storage circuit coil, compare the voltage waveforms and current waveforms with the voltage waveforms and current waveforms under normal conditions one by one, and obtain diagnostic results based on the comparison results.

5. The device according to claim 4, characterized in that The data processing unit is used to determine the core starting stage according to the current waveform. In the core starting stage, if the real-time current is greater than the normal current and the real-time starting time is shorter than the normal starting time, it is determined that the coil turns are short-circuited; if the real-time current is greater than the normal current and the real-time starting time is longer than the normal starting time, it is determined that the core is stuck; wherein the starting time refers to the time required from the start of the coil being energized to the start of the movement of the core in the coil.

6. The device according to claim 5, characterized in that The data processing unit is used to determine the core movement stage according to the electric current waveform. During the core movement stage, if the real-time current increases relative to the normal current, and the time required for the core to move from the beginning to reach the predetermined position is prolonged relative to the normal time, the core is determined to be stuck.

7. The device according to claim 6, characterized in that The data processing unit is used to determine the coil core stop stage based on the current waveform. During the core stop stage, if the real-time current waveform drops rapidly or shows abnormal peaks relative to the normal current waveform, it is determined that the coil turns are short-circuited. If the real-time current waveform fluctuates or shows peaks relative to the normal current waveform, and the real-time current drop speed is inconsistent with the normal current, it is determined that the joint is loose. If the real-time current drop speed is abnormally slow relative to the normal current or the current remains at a high level after stopping, it is determined that the half-shaft is buckled too deeply.

8. The device according to claim 7, characterized in that The data processing unit is used to analyze the frequency distribution of the voltage waveform through Fourier transform. If the high-frequency component increases relative to the frequency distribution of the voltage waveform in a normal state, it is determined that the coil insulation is aged.

9. The device according to claim 1, characterized in that The data processing unit is used to determine that the operation is incomplete or there is a mechanical obstruction if the real-time angle of the switch is smaller than the normal angle during the opening and closing process of the switch.

10. The device according to claim 9, characterized in that The data processing unit is used to determine mechanical failure or improper adjustment if the real-time displacement of the switch is less than or exceeds the expected normal displacement during the opening and closing process of the switch; The data processing unit is used to determine that the operation is unstable if the real-time speed of the switch is too fast or too slow relative to the normal speed during the opening and closing process of the switch.

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