Small arc light protection device

Abstract

The utility model relates to a small arc light protection device, which comprises a circuit board, a shell, a mounting bracket, a transmission optical fiber and a passive arc light sensor, the circuit board is installed in the shell, the shell is installed on a switch cabinet of a power supply system through the installation support, and the passive arc light sensor is connected with the circuit board through the transmission optical fiber. The passive arc light sensor is a plastic passive arc light sensor. Compared with the prior art, the plastic passive arc light sensor is adopted, the size is small, an external power supply is not needed for power supply, the installation and maintenance are convenient, the cost is low, and the hidden danger of electric leakage possibly caused by a traditional metal active arc light sensor is avoided; photoelectric conversion is completed in the device by adopting the plastic optical fiber as a transmission medium, and the plastic optical fiber has the advantages of being excellent in insulating property, not easy to conduct, capable of effectively shielding external electromagnetic interference and noise interference, ensuring stability and accuracy of signals and the like.

Description

Technical Field

[0001] The utility model relates to power supply system protection, in particular to a small arc protection device. Background Art

[0002] Arc flash faults are common in medium and low voltage power supply systems due to factors such as a lack of busbar protection, numerous outgoing lines, frequent operations, relatively close distances between three-phase conductors and the ground, vulnerability to small animals, and inferior equipment manufacturing quality compared to high-voltage equipment. Once an arc flash occurs, the severity of the damage depends on the arc current and the time it takes to clear it. If the fault is not cleared promptly, it can cause minor equipment burns, severe cases such as explosions in switch cabinets, casualties, and even fires.

[0003] Existing arc protection devices use active arc sensors, and the photoelectric conversion is completed outside the device, which makes the wiring complex and susceptible to interference. In addition, many existing arc protection devices are large in size, which leads to inconvenience during installation, commissioning and maintenance. Especially in scenarios with limited space, large devices may take up too much space and affect the layout and operation of other equipment.

[0004] In summary, how to design a smaller arc protection device is a technical problem that needs to be solved. Utility Model Content

[0005] The purpose of the present invention is to provide a small arc protection device in order to overcome the defect of large volume in the above-mentioned prior art.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] According to one aspect of the utility model, a small arc protection device is provided for a power supply system. The protection device includes a circuit board, a housing, a mounting bracket, a transmission optical fiber, and a passive arc sensor. The circuit board is installed in the housing, and the housing is installed on a switch cabinet of the power supply system via the mounting bracket. The passive arc sensor is connected to the circuit board via a transmission optical fiber. The passive arc sensor is a plastic passive arc sensor.

[0008] As an optimal technical solution, the circuit board includes a core board, an arc light collection board, a power board, a bus board and a liquid crystal board. The bus board includes a switch quantity collection circuit, a passive relay output circuit, an RS485 circuit and a GPS timing circuit; the core board, arc light collection board, power board and liquid crystal board are all connected to the bus board.

[0009] As an optimal technical solution, the core board is equipped with a main control chip STM32H723ZGT6 with a main frequency of 550MHz. The main control chip has a built-in ADC acquisition module, 1M byte flash memory and 564K bytes of static random access memory. The main control chip is also connected to a 256M-BIT external flash memory and a 4M×16×4Banks synchronous dynamic random access memory.

[0010] As a preferred technical solution, the power board includes a voltage transformer, a current transformer and a power module. The voltage transformer and current transformer are connected to the ADC acquisition module through a bus board, and the power module provides the required voltage to the circuit board.

[0011] As a preferred technical solution, the arc light collection board is provided with an arc light collection module, and the arc light collection module is connected to the passive arc light sensor via a transmission optical fiber.

[0012] As a preferred technical solution, the passive relay output circuit is configured with an outlet through protection logic; the RS485 circuit is an RS485 circuit that supports IEC60870-5-103 and Modbus-RTU protocols; and the GPS timing circuit is a GPS timing circuit that supports IRIG-B timing.

[0013] As a preferred technical solution, the liquid crystal panel includes a liquid crystal screen, buttons and indicator lights, and the liquid crystal screen is connected to the bus board via an MMI line.

[0014] As a preferred technical solution, the transmission optical fiber is a plastic transmission optical fiber.

[0015] As a preferred technical solution, the housing includes a plastic shell and a front cover, one end of the plastic shell is open, and the front cover covers the open end of the plastic shell; the circuit board is located in the plastic shell.

[0016] As a preferred technical solution, the plastic shell is a plastic shell made of thermoplastic plastic material.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) This utility model adopts a plastic passive arc sensor, which is compact, does not require an external power supply, is easy to install and maintain, is low in cost, and avoids the potential leakage hazards caused by traditional metal active arc sensors;

[0019] 2) The utility model uses plastic optical fiber as the transmission medium, and the photoelectric conversion is completed within the device. The plastic optical fiber itself has excellent insulation performance and is not easy to conduct electricity. It can effectively shield external electromagnetic interference and noise interference, ensuring signal stability and accuracy. At the same time, the flexibility of the plastic optical fiber can adapt to various complex installation environments and is also easy for users to install and wire, thereby improving the monitoring range and monitoring capabilities of the arc sensor.

[0020] 3) The utility model adopts a main control chip with a main frequency of 550MHz, equipped with a 16-bit ADC, which can sample 48 points of high-speed per cycle, monitor arc signals in real time, and support burning different configuration files to achieve different protection functions, including arc single-criteria protection for arc faults, arc overcurrent dual-criteria protection, arc delay protection, arc fault point location, CT disconnection and other functions; and the main control chip has an arc self-test function, which can monitor the real-time working status of the photoelectric conversion module, optical fiber link and passive arc sensor in real time; an LCD panel is provided to inform the user through the LCD screen when working abnormally. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a small arc protection device of the utility model;

[0022] Figure 2 This is a circuit board module diagram of the utility model;

[0023] Figure 3 This is a schematic diagram of the transmission optical fiber structure of the utility model;

[0024] Figure 4 This is a schematic diagram of the structure of the passive arc sensor of the utility model;

[0025] Figure 5 This is a schematic diagram of the wiring terminal structure of the utility model;

[0026] The numbers in the figure show:

[0027] 1. LCD panel, 11. LCD screen, 12. Buttons, 13. Indicator lights, 2. Power board, 21. Voltage transformer, 22. Current transformer, 23. Power module, 3. Bus board, 31. Switching quantity acquisition circuit, 32. Passive relay output circuit, 33. RS485 circuit, 34. GPS timing circuit, 4. Core board, 41. Main control chip, 42. External flash memory, 43. Synchronous dynamic random access memory, 5. Arc light acquisition board, 51. Arc light acquisition module, 6. Front cover, 7. Plastic housing, 8. Front panel, 9. Mounting bracket, 10. Screws. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0029] like Figure 1 As shown, the present invention provides a small arc protection device, including a circuit board, a front cover 6, a housing 7, a mounting bracket 9, screws 10, a transmission fiber, and a passive arc sensor. The circuit board includes a core board 4, an arc light collection board 5, a power board 2, a bus board 3, and an LCD panel 1.

[0030] The core board 4 uses a 550MHz STM32H723ZGT6 as the main control chip 41, with built-in 1M-byte flash memory, 564K-byte static random access memory (SRAM), and ADC acquisition. It is equipped with an external 256M-bit external flash memory 42 (FLASH MEMORY) and 4M×16×4 banks of synchronous dynamic random access memory 43 (SYNCHRONOUS DRAM). The FLASH MEMORY adopts the MX25L256 specification model, supports single-line, dual-line, and four-line SPI control modes, and has a read and write speed of up to 133MHz. The SYNCHRONOUS DRAM adopts the IS42S16160J specification model, supports Auto Refresh (CBR), and supports read and write frequencies of 166, 143, and 133MHz. The main control chip 41 supports the burning of different configuration files to implement various protection functions, including single-criteria arc protection, dual-criteria arc overcurrent protection, arc delay protection, arc fault location, and CT disconnection detection. The main control chip also has an arc self-test function that monitors the real-time operating status of the optoelectronic conversion module, optical fiber link, and passive arc sensor.

[0031] The arc light acquisition board 5 monitors the intensity of external visible or ultraviolet light in real time and transmits this data via optical fiber to the input pins of the ADC on the main control chip 41, monitoring the arc light intensity in real time. The arc light acquisition board 5 contains three high-precision arc light acquisition modules 51, which perform photoelectric conversion within the modules. These modules are installed on the arc light acquisition board 5 and are connected to passive arc light sensors via optical fiber. These passive arc light sensors monitor the intensity of external visible or ultraviolet light in real time and transmit this data to the main control chip 41 via optical fiber. Internal protection logic then determines whether to activate the arc light protection function.

[0032] The power board 2 includes a voltage transformer 21, a current transformer 22, and a power module 23. The voltage and current signals are collected and calculated by the ADC built into the main control chip 41 through the voltage transformer 21 and the current transformer 22. The power, energy, harmonic content and other electrical parameters are then displayed on the LCD screen 11 of the LCD panel 1. The power module 23 supports AC88V~500V, DC88V~360V, and DC20V~60V power supply. Figure 5 As shown, the external interfaces corresponding to the current signal are X2.11-X2.18, and the external interfaces corresponding to the voltage signal are X2.5-X2.9; the interfaces of the power module 23 are X2.1-X2.4.

[0033] The bus board 3 includes 8-way switch quantity acquisition circuit 31, 5-way passive relay output circuit 32, RS485 circuit 33 and GPS timing circuit 34; the signals that can be connected to the switch quantity acquisition circuit 31 include AC / DC110V, AC / DC220V and DC24V / 48V signals; the passive relay output circuit 32 can freely configure the output through the protection logic to cut off the fault arc at the corresponding position; the RS485 circuit 33 supports IEC60870-5-103 and Modbus-RTU protocols; the GPS timing circuit 34 supports IRIG-B timing. Figure 5 As shown, the switch value acquisition circuit 31 corresponds to the switch value input interface X1.14-X1.22, where X1.14 is the switch value input common terminal; the passive relay output circuit 32 corresponds to the switch value output interface X1.0-X1.10; the RS485 circuit 33 and the GPS timing circuit 34 use a unified hardware interface, X1.11-X1.13, and rely on internal selection protocols to achieve function switching.

[0034] The liquid crystal panel 1 comprises a liquid crystal screen 11, a key 12 and an indicator light 13. The indicator light 13 can be selected in red or green.

[0035] like Figure 3 As shown in the figure, the transmission optical fiber is a dual-mode optical fiber made of high-temperature resistant and bendable plastic. It supports one transmission and one reception and can be used with a passive arc light sensor to realize the sensor self-test function.

[0036] like Figure 4 As shown, the passive arc light sensor is made of plastic, is not easy to conduct electricity, and can flexibly sense visible light and ultraviolet light.

[0037] The shell 7 is made of thermoplastic material and has the advantages of high impact resistance, strong heat resistance, and good flame retardancy.

[0038] like Figure 2As shown, the core board 4 is connected to the bus board 3 through the first computer bus (BUS1) and the second computer bus (BUS2), and is powered by the bus board 3; the liquid crystal panel 1 is powered by the bus board 3, and the LCD screen 11 on the liquid crystal panel 1 is connected to the bus board 3 through the MMI line; the signals collected by the arc light collection board 5 and the arc light collection module 51 are transmitted to the bus board 3; the power supply board 2 provides 5V and 24V power to the bus board 3, and is connected to the bus board 3 through the analog input line.

[0039] The top plate of the front cover 6 is the front panel 8. The circuit boards are all located in the housing 7. The power board 2 and bus board 3 are fixed to the housing 7 by pan head screws 10. The housing 7 is fixed to the switch cabinet door by mounting brackets 9. The front cover 6 covers one end of the housing 7 to form a closed structure. Figure 5 As shown, the housing 7 is provided with connection terminals.

[0040] The utility model is compact, economical, has complete arc protection functions, good electromagnetic compatibility, high measurement accuracy, good reliability, and is easy to install and maintain. The passive arc sensor is made of plastic, does not require an external power supply, is low in cost, and avoids the potential leakage risks caused by traditional metal active arc sensors. Plastic optical fiber is used as the transmission medium, and the photoelectric conversion is completed within the device. The plastic optical fiber itself has excellent insulation properties and is not easy to conduct electricity. It can effectively shield external electromagnetic interference and noise interference, ensuring signal stability and accuracy; at the same time, the flexibility of the plastic optical fiber can adapt to various complex installation environments, and a more flexible optical path can be designed, which is easy for users to install and wire, thereby improving the monitoring range and monitoring capabilities of the arc sensor. The main control chip 41 of the utility model is equipped with an arc self-test function, which can monitor the real-time working status of the photoelectric conversion module, optical fiber link and passive arc sensor in real time, and inform the user through the human-machine interface when the work is abnormal. It uses a main control chip 41 with a main frequency of 550MHz, equipped with a 16-bit ADC, and can perform 48-point high-speed sampling per cycle, which can monitor arc signals in real time. In addition, it is equipped with arc single-criteria protection, arc overcurrent dual-criteria protection, arc delay protection, arc fault point location and CT disconnection functions for arc faults.

[0041] The utility model can be widely used in power distribution systems such as substations, industrial and mining enterprises, hospitals, schools, commercial plazas and large buildings, and can monitor the real-time status of arc light in each power distribution circuit in real time, meeting the user's requirements for safe operation and reliability of power energy in power systems with voltage levels of 20kV and below.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A small arc protection device for a power supply system, characterized in that: The protection device comprises a circuit board, a housing, a mounting bracket (9), a transmission optical fiber, and a passive arc light sensor; the circuit board is mounted in the housing, the housing is mounted on a switch cabinet of a power supply system via the mounting bracket (9), and the passive arc light sensor is connected to the circuit board via the transmission optical fiber; the passive arc light sensor is a plastic passive arc light sensor; The circuit board comprises a core board (4), an arc light collection board (5), a power board (2), a bus board (3) and a liquid crystal board (1); the bus board (3) comprises a switch quantity collection circuit (31), a passive relay output circuit (32), an RS485 circuit (33) and a GPS timing circuit (34); the core board (4), the arc light collection board (5), the power board (2) and the liquid crystal board (1) are all connected to the bus board (3).

2. A small arc protection device according to claim 1, characterized in that: The core board (4) is provided with a main control chip (41) of STM32H723ZGT6 with a main frequency of 550MHz. The main control chip (41) has a built-in ADC acquisition module, a 1M-byte flash memory and a 564K-byte static random access memory. The main control chip (41) is also connected to a 256M-BIT external flash memory (42) and a synchronous dynamic random access memory (43).

3. A small arc protection device according to claim 2, characterized in that: The power supply board (2) comprises a voltage transformer (21), a current transformer (22) and a power supply module (23); the voltage transformer (21) and the current transformer (22) are connected to the ADC acquisition module via the bus board (3); and the power supply module (23) provides the required voltage to the circuit board.

4. A small arc protection device according to claim 1, characterized in that: The arc light collection board (5) is provided with an arc light collection module (51), and the arc light collection module (51) is connected to a passive arc light sensor via a transmission optical fiber.

5. A small arc protection device according to claim 1, characterized in that: The passive relay output circuit (32) is configured as an outlet through protection logic; the RS485 circuit (33) is an RS485 circuit (33) that supports IEC60870-5-103 and Modbus-RTU protocols; and the GPS timing circuit (34) is a GPS timing circuit (34) that supports IRIG-B timing.

6. A small arc protection device according to claim 1, characterized in that: The liquid crystal panel (1) comprises a liquid crystal screen (11), a button (12) and an indicator light (13), and the liquid crystal screen (11) is connected to the bus board (3) via an MMI line.

7. A small arc protection device according to claim 1, characterized in that: The transmission optical fiber is a plastic transmission optical fiber.

8. The small arc protection device according to claim 1, characterized in that: The housing comprises a plastic shell (7) and a front cover (6); one end of the plastic shell (7) is open, and the front cover (6) covers the open end of the plastic shell (7); and the circuit board is located inside the plastic shell (7).

9. The small arc protection device according to claim 1, characterized in that: The plastic shell (7) is a plastic shell made of thermoplastic plastic material.

Images