A voltage transformer secondary grounding on-line monitoring device

Abstract

The utility model relates to a kind of voltage transformer secondary grounding on-line monitoring device, including device shell, the front end of device shell is equipped with front baffle, the rear end of device shell is equipped with rear baffle, the left and right sides of rear baffle are equipped with annular heat dissipation hole, the center position of rear baffle is equipped with connector port, the upper end of device shell is equipped with cover plate, the lower end rear side left end of device shell is equipped with power supply heat dissipation frame,and device shell inside rear end left side is equipped with power supply support, the inside of power supply support is equipped with industrial power module, the lower side of industrial power module is integrated with heat dissipation fin, heat dissipation fin is aligned power supply heat dissipation frame, the right side of power supply support is equipped with circuit board support, the upper end of circuit board support is equipped with circuit board, the circuit board is electrically connected with connector port, with the advantage that the whole monitoring device keeps good electrical performance and mechanical reliability in long-term operation, improve the stability and service life of device overall.

Description

Technical Field

[0001] This utility model relates to the field of online monitoring technology for secondary grounding of voltage transformers, and in particular to an online monitoring device for secondary grounding of voltage transformers. Background Technology

[0002] Voltage transformers (TVs) are one of the important pieces of equipment in substations. Their secondary side must have one and only one grounding point. If there are multiple grounding points in the TV secondary circuit at the same time, there is a risk of misjudgment, maloperation, or failure to operate by the relay protection device, which threatens the safe and stable operation of the power grid. At present, the detection and investigation of multiple grounding points mainly adopts the method of manual periodic inspection, which has the problems of "difficulty in detection, difficulty in investigation, and difficulty in maintenance".

[0003] Patent application number CN202211406369.3 is a Chinese invention patent that discloses an N600 online monitoring device, including a device body and a sampling terminal electrically connected to the device body for collecting N600 current signals. The device body includes a housing and a circuit board disposed in the housing. The front end of the housing is provided with a human-machine interaction panel, and the rear end of the housing is provided with a plug-in port panel. The sampling terminal is connected to the plug-in port panel through a wire. This invention monitors the N600 grounding point current in real time across the entire substation. It determines whether multiple grounding points have occurred at N600 using preset values. Once multiple grounding occurs, an alarm is issued, and a "multi-point grounding action signal" is output to the substation's computer monitoring system, alerting maintenance personnel to take action. This achieves real-time monitoring of grounding points, effectively preventing multiple grounding at N600 points, improving the reliability of relay protection, reducing protection malfunctions and power outages, and ensuring the safe and stable operation of the power grid. However, this device has the following problems: firstly, its overall heat dissipation and dust prevention are poor; secondly, it cannot reduce the vibration of the internal circuit board, affecting the accuracy of data acquisition. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies. By incorporating annular heat dissipation holes, ventilation openings, and a power supply heat dissipation frame into the device housing, and integrating heat dissipation fins into the industrial power module within the heat dissipation frame, all heat dissipation holes are equipped with dust filters. This ensures that key components such as the power module and circuit board maintain suitable temperatures during long-term operation, preventing performance degradation or malfunctions due to overheating. This solves the technical problem of poor overall heat dissipation and dust prevention in existing devices. The inner side of the circuit board bracket uses nitrile rubber shock-absorbing strips, which are flush with the mounting base and abut against the inner wall. The circuit board is mounted on the top, protecting it from impacts that may occur during the operation of voltage transformer equipment, ensuring data acquisition accuracy. This solves the technical problem that existing devices cannot reduce the vibration of internal circuit boards, affecting data acquisition accuracy.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An online monitoring device for secondary grounding of a voltage transformer includes a housing. A front baffle is located at the front end of the housing, and a rear baffle is located at the rear end. Annular heat dissipation holes are located on the left and right sides of the rear baffle, and a connection port is located at the center of the rear baffle. A cover plate is located at the top of the housing. A power heat dissipation frame is located at the lower left rear end of the housing, and a power support is located on the left rear end inside the housing. An industrial power module is located inside the power support, and heat dissipation fins are integrated on the lower side of the industrial power module, aligning with the power heat dissipation frame. A circuit board support is located on the right side of the power support, and a circuit board is located on the upper end of the circuit board support. The circuit board is electrically connected to the connection port. Uniformly distributed heat dissipation holes are located on the left and right sides of the housing.

[0007] As a preferred embodiment, the connection ports include voltage input and current input ports, relay dry contact output ports, RS communication ports, analog output ports, and power input ports arranged in sequence, and the voltage input and current input ports are connected to snap-fit ​​CT current transformers.

[0008] As a preferred embodiment, the annular heat dissipation holes and the interior of the heat dissipation holes are all equipped with dust filters.

[0009] As a preferred embodiment, the front baffle includes an indicator light unit, which includes a power indicator light, a fault indicator light, and an operation indicator light arranged in sequence. A display unit is provided on the right side of the indicator light unit, and an operation button unit is provided on the right side of the display unit. The left and right ends of the front baffle protrude from the device housing, and mounting holes are provided on the upper and lower sides of the left and right ends of the front baffle.

[0010] As a preferred embodiment, the circuit board bracket includes a mounting base, with positioning screw holes on the upper left and right sides of the mounting base. The circuit board is mounted on the mounting base using screws. Four nitrile rubber shock-absorbing strips are provided on the inner side of the mounting base.

[0011] As another preferred embodiment, the nitrile rubber damping strip is 2mm higher than the mounting base, and the nitrile rubber damping strip abuts against the left and right inner walls of the mounting base.

[0012] The beneficial effects of this utility model are:

[0013] (1) In this utility model, a power heat dissipation frame is set on the rear side of the lower end of the device housing and aligned with the heat dissipation fins under the industrial power module integrated inside the power bracket. This allows the heat generated by the power module during operation to be quickly conducted to the external environment through the heat dissipation fins, thus preventing heat from accumulating inside the housing and causing electronic components to age or fail.

[0014] (2) In this utility model, the device housing is provided with evenly distributed heat dissipation holes on the left and right sides, and the rear baffle is provided with annular heat dissipation holes on both sides. These multi-directional heat dissipation channels form a good air convection path, which helps to accelerate the discharge of internal hot air and the entry of external cold air, thereby achieving efficient natural ventilation and heat dissipation. In addition, the heat dissipation holes are equipped with dust filters, which effectively block dust from entering the housing and prevent dust accumulation from causing short circuits or affecting the heat dissipation efficiency of electronic components, thereby improving the overall stability and service life of the device.

[0015] (3) In this utility model, four nitrile rubber shock-absorbing strips are set on the inner side of the circuit board bracket and the positioning screw holes on both sides of the mounting base are used to fix the circuit board firmly on the bracket with screws. At this time, the lower side of the circuit board will evenly abut against the nitrile rubber strips. The four nitrile rubber strips can evenly support the circuit board. The nitrile rubber strips can reduce the impact of external vibration on the circuit board and prevent the circuit board from fatigue fracture, solder joint detachment or poor contact due to vibration. It is particularly suitable for the common operating environment of frequent vibration and strong electromagnetic interference in power systems, so that the entire monitoring device can maintain good electrical performance and mechanical reliability in long-term operation and ensure continuous and accurate monitoring of the secondary grounding status of the voltage transformer.

[0016] In summary, this lamp has the advantages of maintaining good electrical performance and mechanical reliability of the entire monitoring device during long-term operation, improving the overall stability and service life of the device, and is especially suitable for the field of online monitoring technology for secondary grounding of voltage transformers. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0019] Figure 2 This is a bottom view of the device housing and a schematic diagram of the power supply heat dissipation frame position in this utility model.

[0020] Figure 3 This is a schematic diagram of the rear baffle structure and the location of the connector port in this utility model.

[0021] Figure 4 This is a structural diagram of the internal structure of the device housing, a power supply bracket, and a schematic diagram showing the positions of the circuit board bracket in this utility model.

[0022] Figure 5This is a schematic diagram of the circuit board support structure in this utility model. Detailed Implementation

[0023] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0024] Example 1

[0025] like Figures 1 to 5As shown, this utility model provides an online monitoring device for secondary grounding of voltage transformers, including a device housing 1. The device housing 1 is a standard 1U chassis size, which is convenient for installation in power system cabinets and adapts to the space specifications of power control cabinets. The front end of the device housing 1 is provided with a front baffle 2, and the rear end of the device housing 1 is provided with a rear baffle 3. The left and right sides of the rear baffle 3 are provided with annular heat dissipation holes 32, and the center of the rear baffle 3 is provided with a plug-in port 31. The upper end of the device housing 1 is provided with a cover plate 4, and the lower left rear end of the device housing 1 is provided with a power supply heat dissipation frame 14. The rear left side of the device housing 1 is provided with a power supply bracket 11. The power supply bracket 11 has a groove inside, and the groove has positioning screw holes on both the left and right sides. The slot is used to hold the industrial power supply module. The screw holes secure the industrial power supply, which supports dual input modes and has an internal rectifier, allowing for DC and AC power installation. It is suitable for various substations. The power supply bracket 11 houses the industrial power supply module, and the lower side of the industrial power supply module integrates heat dissipation fins made of high thermal conductivity aluminum. The heat dissipation fins are aligned with the power heat dissipation frame 14 through precise design. Rubber pads are provided around the lower side of the slot, and the hole in the center is the location of the power heat dissipation frame 14. The lower side of the industrial power supply module abuts against the rubber pads, providing cushioning and preventing damage to the power supply module due to vibration during transportation or operation. To prevent displacement or damage and thus improve the stability of the entire power system, the heat sink fins are aligned with the power heat sink frame 14 to form an efficient heat conduction path, allowing the heat generated by the power module during operation to be quickly conducted to the outside of the housing. A circuit board support 12 is located on the right side of the power bracket 11, with a circuit board on its upper end. The circuit board includes a processor module, a current input module, a voltage input module, a power conversion module, an isolation transmitter module, and a relay dry contact output module. The current input module, voltage input module, power conversion module, isolation transmitter module, and relay dry contact output module are coupled to the processor module. The current input module and voltage input module are coupled to the voltage input on the connector port 31. The input and current input ports 311 are connected to the analog output port 314 and relay dry contact output port 312 on the plug-in port 31, respectively. The processor module is responsible for acquiring, processing, and logically judging voltage and current signals to realize real-time monitoring and alarm of the secondary grounding status of the voltage transformer. The current input module and voltage input module are connected to the secondary side signal of the external voltage transformer and the current signal output by the snap-on CT current transformer 5 through the voltage input and current input ports 311 on the plug-in port 31. The module has a signal conditioning unit, including filtering, amplification, isolation and other circuits, to ensure the accuracy and safety of signal acquisition.The power conversion module converts the power supplied by the industrial power module into various voltage levels required by the system's modules, ensuring stable system operation. The isolation transmitter module converts the data processed by the processor module into a standard 4-20mA analog current signal and outputs it through the analog output port 314. When a grounding abnormality is detected, the processor controls the relay dry contact output module to activate the relay and output a dry contact signal to trigger an external alarm or linkage control device. The circuit board is electrically connected to the connector port 31. The device housing 1 has evenly distributed heat dissipation holes 13 on its left and right sides, forming multi-directional airflow paths to improve heat dissipation efficiency.

[0026] Furthermore, the connection port 31 includes voltage input and current input ports 311 arranged in sequence. These ports are used to receive the voltage signal from the secondary side of the voltage transformer and the current signal collected by the snap-on CT current transformer 5, serving as the input signal source for the monitoring device. A relay dry contact output port 312 is used to output a fault alarm signal, which can be connected to an external alarm system or control loop to achieve remote linkage control. An RS485 communication port 313 is used to communicate with a host computer, facilitating remote monitoring and centralized data management. An analog output port 314 is also included. This is an isolation transmitter module used to output 4-20mA analog current signals. Power input port 315 is used to connect to an external AC or DC power supply to power the internal industrial power module. The voltage and current input ports 311 are connected to a snap-fit ​​CT current transformer 5. The snap-fit ​​CT current transformer 5 is a precision open-type current transformer with a ring structure, including a hinged upper ring and a snap-fit ​​lower ring, with a wire through-hole in the middle. It features high precision, low power consumption, and wide frequency response. The snap-fit ​​CT current transformer 5 adopts a hinged upper and lower ring structure, facilitating on-site installation. It can be snapped onto the measured conductor without disconnecting the wire, making it suitable for various distribution cabinet environments.

[0027] Furthermore, the annular heat dissipation hole 32 and the heat dissipation hole 13 are both equipped with dust filters. The dust filters can dissipate heat from the inside of the device while preventing dust, thus ensuring the long-term operational stability of the device.

[0028] Furthermore, the front baffle 2 includes an indicator light unit 21, which includes a power indicator light 211, a fault indicator light 212, and an operation indicator light 213 arranged in sequence. The power indicator light 211 is a green LED, indicating that the device is powered on and operating normally. The fault indicator light 212 is a red LED, which lights up when a grounding abnormality, communication interruption, or module failure is detected. The operation indicator light 213 is a yellow LED, used to indicate the relay operation status. The operation criteria are: sudden current: after the sudden current is greater than 20mA, it lasts for 7 seconds; steady-state current: greater than or equal to 50mA, it lasts for 7 seconds; the operation return criterion is: when the current drops to 50% of the steady-state value, the operation contact returns. Once multiple grounding occurs, the device... An alarm message is issued, and a "multi-point grounding action signal" action contact is output to the substation computer monitoring system to remind the operation and maintenance personnel to handle the situation, thereby avoiding multiple grounding of N600 and causing the protection device to fail to operate or malfunction. In addition, a display unit 22 is provided on the right side of the indicator unit 21. The display unit is a display screen that can display information such as voltage, current, grounding status, and fault codes. An operation button unit 23 is provided on the right side of the display unit 22. The button unit 23 is used for local parameter setting and fault reset operation. The left and right ends of the front baffle 2 protrude from the device housing 1. The upper and lower sides of the protruding parts of the left and right ends of the front baffle 2 are provided with mounting holes 24. The mounting holes 24 are used to fix the device to the electrical control cabinet or bracket with screws to ensure a firm installation.

[0029] Furthermore, the circuit board support 12 includes a mounting base 121, which is made of high-strength engineering plastic. The mounting base 121 has positioning screw holes 122 on both the upper left and right sides. The positioning screw holes 122 are used to install the circuit board with screws, which firmly fix the circuit board to the mounting base 12, ensuring that the circuit board does not shift during operation. The mounting base 121 has four nitrile rubber shock-absorbing strips 123 on its inner side. The strips are made of highly elastic nitrile rubber material and have excellent shock absorption, buffering and anti-aging properties.

[0030] Furthermore, the nitrile rubber damping strip 123 is 2mm higher than the mounting base 121, and the nitrile rubber damping strip 123 abuts against the inner walls of the mounting base 121 on the left and right sides. The structure of the nitrile rubber damping strip 123 being slightly higher than the mounting base 121 by 2mm allows the circuit board to fully contact the damping strip after installation, forming a uniform pressure distribution. This structural design ensures that the circuit board can be effectively buffered by the nitrile rubber damping strip 123 when subjected to external vibration, avoiding damage to the circuit board due to excessive local force. At the same time, the design of the nitrile rubber damping strip 123 abutting against the inner walls of the mounting base 121 on the left and right sides also enhances its structural stability and prevents the damping strip from shifting or deforming during use.

[0031] Working process: First, the device connects to the secondary side signal of the voltage transformer through the voltage input and current input ports 311 of the plug-in port 31. At the same time, it works with the snap-on CT current transformer 5 to collect the grounding conductor current signal to achieve real-time data input. Then, the input voltage / current signal is transmitted to the circuit board, where the current input module and voltage input module perform signal conditioning, and then input to the processor module for real-time analysis to determine whether the grounding status is abnormal. If the processor detects a grounding abnormality, it immediately triggers the relay dry contact output module to send an alarm signal through the relay dry contact output port 312 of the plug-in port 31. At the same time, the isolation transmitter module converts the monitoring data into a 4-20mA analog current signal and outputs the "multi-point grounding action signal" action contact to the substation computer monitoring system through the analog output port 314 to remind the operation and maintenance personnel to handle the situation.

[0032] Secondly, when external vibrations, such as mechanical vibrations from the electrical cabinet, are transmitted to the device, the rubber pads at the bottom of the power supply bracket 11 compress and deform to absorb the impact energy, preventing the power module from shifting. Simultaneously, the four nitrile rubber damping strips 123 inside the circuit board bracket 12 uniformly buffer the vibrations received by the circuit board through elastic deformation, preventing solder joints from falling off or components from loosening, ensuring signal processing accuracy. Furthermore, when the industrial power module starts up, the heat generated during operation is conducted through the integrated aluminum heat sink fins at the bottom to the power supply heat sink frame 14 at the lower end of the device housing 1. The heat dissipation holes 13 on the left and right sides of the device housing 1 and the annular heat dissipation hole 32 on the rear side also facilitate the dissipation of internal heat, achieving natural ventilation inside the device.

[0033] In the description of this utility model, it should be understood that the terms "front and back", "left and right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0034] Of course, those skilled in the art should understand that the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple. The term "a" should not be understood as a limitation on the quantity.

[0035] The above description is merely a preferred embodiment of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art under the technical guidance of this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. An on-line monitoring device for voltage transformer secondary ground, characterized in that: The device includes a housing (1), a front baffle (2) at the front end of the housing (1), a rear baffle (3) at the rear end of the housing (1), annular heat dissipation holes (32) on the left and right sides of the rear baffle (3), a plug-in port (31) at the center of the rear baffle (3), a cover plate (4) at the upper end of the housing (1), a power heat dissipation frame (14) at the lower rear left end of the housing (1), and a power support (11) at the rear left side inside the housing (1). An industrial power module is installed inside the power support (11), and heat dissipation fins are integrated on the lower side of the industrial power module. The heat dissipation fins are aligned with the power heat dissipation frame (14). A circuit board support (12) is installed on the right side of the power support (11), and a circuit board is installed on the upper end of the circuit board support (12). The circuit board is electrically connected to the plug-in port (31). The housing (1) has evenly distributed heat dissipation holes (13) on the left and right sides.

2. The on-line monitoring device for secondary ground of voltage transformer according to claim 1, characterized in that, The connector (31) includes a voltage input and current input port (311), a relay dry contact output port (312), an RS485 communication port (313), an analog output port (314), and a power input port (315) arranged in sequence. The voltage input and current input port (311) is connected to a snap-fit ​​CT current transformer (5).

3. The online monitoring device for secondary grounding of a voltage transformer according to claim 1, characterized in that, The annular heat dissipation hole (32) and the heat dissipation hole (13) are both equipped with dust filters.

4. The online monitoring device for secondary grounding of a voltage transformer according to claim 1, characterized in that, The front baffle (2) includes an indicator light unit (21), which includes a power indicator light (211), a fault indicator light (212), and an action indicator light (213) arranged in sequence. A display unit (22) is provided on the right side of the indicator light unit (21), and an operation button unit (23) is provided on the right side of the display unit (22). The left and right ends of the front baffle (2) protrude from the device housing (1), and the upper and lower sides of the left and right ends of the front baffle (2) are provided with mounting holes (24).

5. The on-line monitoring device for voltage transformer secondary ground fault according to claim 1, characterized in that, The circuit board bracket (12) includes a mounting base (121), and the mounting base (121) is provided with positioning screw holes (122) on the upper left and right sides. The positioning screw holes (122) are used to install the circuit board by screws. The mounting base (121) is provided with four nitrile rubber shock-absorbing strips (123) on the inner side.

6. The on-line monitoring device for voltage transformer secondary ground fault according to claim 5, characterized in that, The nitrile rubber damping strip (123) is 2mm higher than the mounting base (121), and the nitrile rubber damping strip (123) abuts against the left and right inner walls of the mounting base (121).

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