Drop-out fuse on-site maintenance self-opening system based on infrared control

Abstract

The invention discloses a drop-out fuse field maintenance self-opening system based on infrared control, and belongs to the technical field of electrical equipment maintenance assistance. According to the method, an infrared receiving module, an instruction verification unit and a local control link are integrated, a worker sends an opening instruction through an infrared remote controller on site, a fuse electromagnetic driving mechanism is triggered to execute opening operation, and the problems that in traditional manual falling operation, equipment needs to be in close contact, safety is low, and operation difficulty is large are solved. The infrared instruction response time is less than or equal to 20ms, the opening operation success rate is greater than or equal to 99%, fuse opening can be rapidly realized in an electrified or power-off maintenance scene, and the safety and efficiency of field maintenance are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of power system distribution network equipment maintenance technology, specifically to an infrared control self-tripping system for drop-out fuses, applicable to on-site maintenance scenarios of drop-out fuses in 10kV and below distribution networks. Background Technology

[0002] Field maintenance of drop-out fuses (such as cleaning surface contaminants, replacing fuse tubes, and testing insulation performance) must be performed with the equipment in the open position to ensure the personal safety of maintenance personnel. Currently, the mainstream opening operation methods in the industry have significant technical defects: 1. It relies on the communication link between the master station and the device (such as 4G / LoRa). However, in remote mountainous areas, dense building clusters, and around substations, communication is often interrupted due to signal obstruction and electromagnetic interference. At this time, remote commands cannot be delivered, directly hindering the maintenance work. In addition, remote operation requires the master station's authorization approval process, which results in a delayed response in emergency maintenance scenarios (average time ≥ 5 minutes), affecting the efficiency of fault handling.

[0003] 2. The traditional method requires maintenance personnel to hold an insulated rod and pull the high-voltage insulating pull ring, forcing the fuse to drop and trip. This operation carries multiple risks: ① It requires close contact with the equipment (usually ≤2 meters), which can easily lead to electric shock if the equipment insulation is aging or the operation is improper; ② When working at height, the operating angle is limited, and uneven force on the pull ring may cause the equipment to tilt, the wires to loosen, and secondary faults to occur; ③ The operation takes a long time (average ≥30 seconds) and requires two people (one to operate and one to monitor), resulting in high labor costs; ④ There is a lack of clear operational feedback. If the pull ring is mechanically jammed, it is difficult to quickly determine whether the trip is in place, increasing the risk of misjudgment. Summary of the Invention

[0004] This invention aims to provide an infrared-controlled self-tripping system for field maintenance of drop-out fuses. Through the collaborative design of infrared directional communication, multi-level security verification, localized control, and real-time feedback, it solves the problems of traditional field tripping operations relying on remote communication, low security, complex operation, and easy malfunction. It achieves "non-contact, high security, and high efficiency" tripping control in maintenance scenarios, ensuring the safety of maintenance personnel and the stable operation of the power distribution network.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an infrared-controlled field maintenance self-tripping system for drop-out fuses, which works in conjunction with the original main control unit, electromagnetic drive mechanism, and remote signaling unit of the fuse. Its hardware architecture includes an infrared receiving unit, an instruction parsing module, a security verification unit, a local control unit, a status feedback unit, and a linkage protection module. The functions and technical details of each module are as follows: The infrared receiving unit receives the on-site infrared tripping command; The instruction parsing module decodes and identifies the specific tripping instruction; The security verification unit performs dual verification of permissions and status. The local control unit triggers the electromagnetic drive mechanism to perform a circuit breaker trip. The status feedback unit returns the operation result. The infrared receiving unit uses a 38kHz carrier frequency, a receiving angle ≥60°, an effective receiving distance of 5-10m, and includes a filtering circuit to eliminate infrared interference.

[0006] The instruction parsing module has a built-in infrared encoding library that only recognizes the "maintenance trip" instruction. The parsed content includes an 8-bit operation permission code and a 16-bit trip confirmation code.

[0007] The security verification unit includes authorization verification (comparing the pre-stored authorization code) and status verification (detecting that the circuit is closed and there is no fault). The circuit is allowed to open after both verifications are passed.

[0008] The local control unit outputs a 15ms pulse command through the optocoupler isolation interface to control the electromagnetic coil to pass a reverse current to trigger the circuit breaker to trip.

[0009] The status feedback unit provides feedback on whether the circuit breaker tripped successfully or failed via a 40kHz infrared response signal and a status indicator light.

[0010] Compared with the prior art, the present invention has the following significant advantages: 1. Enables non-contact operation from 5-10m, completely avoiding close contact between maintenance personnel and live equipment, reducing the risk of electric shock by 100%; Dual safety verification mechanism (authorization + status) ensures that only authorized personnel can operate, and automatically detects the line status before tripping, eliminating tripping with faults, reducing the misoperation rate to below 0.1‰; Optical isolation and drive protection circuit completely isolate the control module from the high-voltage circuit, so that module failure will not affect the operation of the main circuit, and electrical safety complies with GB / T16927.1-2011 standard.

[0011] 2. The infrared command response time is ≤20ms, and the total time for the tripping operation (from the command being sent to the tripping position) is ≤55ms (including the action time of the electromagnetic drive mechanism), which greatly improves efficiency compared with traditional manual operation; a single person can complete the operation (no supervision required), reducing labor costs by 50%; real-time status feedback (sound and light + infrared response) shortens the operation result confirmation time to 1 second, avoiding repeated operations.

[0012] 3. The anti-interference filtering circuit of the infrared receiver unit enables the device to achieve a command recognition success rate of ≥99.5% in strong electromagnetic environments (such as around substations, where electromagnetic interference intensity ≤100V / m); the receiving angle is ≥60°, so maintenance personnel do not need to precisely aim at the device and can operate it from below the pole or the side of the device, adapting to complex installation scenarios; the operating temperature range is -40℃~+70℃, and the humidity is ≤95%RH (non-condensing), meeting the needs of use in harsh outdoor environments.

[0013] 4. It adopts a universal infrared remote control (customizable with a waterproof shell). The buttons are only set to "Break Off" and "Maintenance Complete". The operation logic is simple and the training time for new maintenance personnel is ≤30 minutes. The status feedback is intuitive (indicator light + remote control prompts). No professional knowledge is required to judge the operation results, reducing the reliance on personnel skills. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a block diagram of the overall structure of the method of the present invention, showing the connection relationship between each module of the method and the original fuse system; Figure 3 This is a schematic diagram of the infrared receiving unit circuit of the present invention; Figure 4 This is a schematic diagram of the workflow of the present invention, illustrating the entire process from the sending of an instruction to the completion of the operation; In the diagram: 1-Infrared receiving unit, 101-Infrared photoelectric sensor, 102-RC filter circuit, 103-Operational amplifier, 104-Level conversion circuit, 105-Power supply module, 2-Command parsing module, 3-Safety verification unit, 4-Remote signaling unit, 5-Telemetry unit, 6-Local control unit, 7-Electromagnetic drive mechanism, 701-Closing and closing coil, 702-Silicon steel rod, 8-Status feedback unit, 9-Infrared remote controller, 10-Interlocking protection module, 11-Main control unit, 12-Status indicator light. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] Example The infrared-controlled drop-out fuse field maintenance self-tripping system works in conjunction with the original fuse main control unit, electromagnetic drive mechanism, and remote signaling unit. Its hardware architecture includes an infrared receiving unit, command parsing module, security verification unit, local control unit, status feedback unit, and linkage protection module. The functions and technical details of each module are as follows: The infrared receiving unit receives the on-site infrared tripping command; The instruction parsing module decodes and identifies the specific tripping instruction; The security verification unit performs dual verification of permissions and status. The local control unit triggers the electromagnetic drive mechanism to perform a circuit breaker trip. The status feedback unit returns the operation result. The infrared receiving unit uses a 38kHz carrier frequency, a receiving angle ≥60°, an effective receiving distance of 5-10m, and includes a filtering circuit to eliminate infrared interference.

[0017] The instruction parsing module has a built-in infrared encoding library that only recognizes the "maintenance trip" instruction. The parsed content includes an 8-bit operation permission code and a 16-bit trip confirmation code.

[0018] The security verification unit includes authorization verification (comparing the pre-stored authorization code) and status verification (detecting that the circuit is closed and there is no fault). The circuit is allowed to open after both verifications are passed.

[0019] The local control unit outputs a 15ms pulse command through the optocoupler isolation interface to control the electromagnetic coil to pass a reverse current to trigger the circuit breaker to trip.

[0020] The status feedback unit provides feedback on whether the circuit breaker tripped successfully or failed via a 40kHz infrared response signal and a status indicator light.

[0021] Specifically, 1. Infrared receiving unit: Infrared photoelectric sensor: HS0038 integrated receiver head is selected, with a working frequency of 38kHz (compatible with the carrier frequency of general infrared remote control), a receiving angle ≥60° (horizontal / vertical direction), an effective receiving distance of 5-10m (adjustable by remote control transmission power), and a response time ≤10μs, ensuring stable reception of commands within the range of equipment installation height (3-10m) and operating angle; Anti-interference filtering circuit: A second-order RC low-pass filter network (resistor R=10kΩ±1%, capacitor C=100nF±5%) is adopted, with a cutoff frequency of 38kHz±2kHz. It can filter out broadband infrared interference generated by sunlight (infrared band concentrated in 500-2000nm) and industrial equipment (such as welding machines and frequency converters), thereby improving the signal-to-noise ratio to ≥40dB.

[0022] Signal amplification module: The LMV7219 low-noise operational amplifier amplifies the weak signal (amplitude 20-500μV) output by the sensor to 3.3VTTL level. The amplification factor can be calibrated by an adjustable resistor (10kΩ) (typical gain 100-500 times) to ensure that weak signals (such as commands at 10m) can still be effectively identified.

[0023] Level conversion circuit: The 74LVC1T45 chip enables 3.3V and 5V level compatibility, adapting to the input requirements of subsequent digital circuits and avoiding signal distortion caused by level mismatch.

[0024] 2. The instruction parsing module, based on the STM32L051 low-power microcontroller (32MHz), is responsible for decoding and validating the received infrared signals. Its core functions include: Encoding library storage: Built-in dual encoding system, one is the general NEC encoding (supporting mainstream infrared remote controls on the market), and the other is the custom encrypted encoding (using Manchester encoding format, including 8-bit device address code, 16-bit instruction code, and 8-bit check code). The encoding mode can be switched through software configuration to prevent accidental triggering by non-dedicated remote controls.

[0025] Decoding process: ① Detect the pulse width of the infrared signal (in NEC encoding, logic "0" is 560μs high level + 560μs low level, and logic "1" is 560μs high level + 1680μs low level); ② Extract the address code, instruction code, and check code; ③ Verify the data integrity using the CRC16 check algorithm. If the check fails, discard the instruction.

[0026] Command filtering: It only responds to the "maintenance trip" command and automatically filters other infrared signals with a filtering efficiency of ≥99.9%.

[0027] 3. Security verification unit: This unit establishes a dual verification mechanism to ensure the legality and security of the circuit breaker operation, including an authorization verification submodule and a status verification submodule. Authorization Verification: Ten sets of authorization codes (8-bit binary codes) are pre-stored in the AT24C02 EEPROM (capacity 256 bytes, supports I²C communication, data retention time ≥ 10 years). The authorization codes are stored using AES-128 encryption to prevent malicious cracking. During verification, the parsed authorization code is compared with the stored value, allowing a 1-bit data error (to accommodate slight interference in signal transmission). If a match is found, the authorization verification is passed.

[0028] Status Verification: The system interacts with the remote signaling unit and telemetry unit via the SPI interface to obtain the device's current status parameters in real time: ① The opening / closing status fed back by the remote signaling unit (must be "closed in place"); ② The line current collected by the telemetry unit (must be ≤10% of the rated current to avoid opening under load); ③ The fault indicator status (must have no short-circuit / ground fault signal). Status verification is passed only when all parameters meet safety conditions.

[0029] After both verifications pass, a "permit to open" signal (high level 3.3V) is output to the local control unit; if either verification fails, a prohibition signal is output and the reason for failure is recorded (such as "permission mismatch" or "line overcurrent").

[0030] 4. The local control unit, serving as the execution terminal for the tripping command, interfaces with the control unit of the original electromagnetic drive mechanism of the fuse, and includes an optocoupler isolation circuit, a pulse generation module, and a drive protection circuit. Optocoupler isolation circuit: The TLP521-4 optocoupler is used to achieve electrical isolation between the control circuit (3.3V) and the drive circuit (24V). The isolation voltage is ≥2500Vrms to prevent high voltage interference from entering the control module.

[0031] Pulse generation module: After receiving the "allow opening" signal, it generates a 15ms DC pulse signal (voltage 24V, current 1.5A) to match the opening action requirements of the electromagnetic drive mechanism (the electromagnetic coil needs to reverse current for 15ms during opening).

[0032] Drive protection circuit: Integrated overcurrent protection (using LM317 current limiting chip, threshold 2A) and reverse connection protection (diode D1N4007) to prevent module damage caused by coil short circuit or wiring error.

[0033] 5. Status feedback unit, providing real-time feedback on the tripping operation results to maintenance personnel, including an infrared response submodule and a status indication submodule: Infrared response submodule: It adopts IR333-A infrared emitting tube (wavelength 940nm). After the tripping operation is completed (the remote signaling unit feedback "tripping in place"), it sends a 40kHz carrier confirmation signal (encoded in the format of "device address + operation result + timestamp", lasting 500ms). After the maintenance personnel's remote control receives the signal, it will indicate success through a buzzer (3 short beeps) and LED flashing (green, 3 times / second).

[0034] Status indicator submodule: The device body is equipped with red and green dual-color LED indicator lights (5mm in diameter, high brightness ≥1000mcd): ① When the circuit breaker is successfully tripped, the red LED flashes 3 times (on for 1 second, off for 1 second); ② When the operation fails (such as verification failure or circuit breaker tripping timeout), the green LED stays on and sends a failure code through the infrared response submodule for the remote control to display the specific reason.

[0035] During operation, After the device is powered on, it enters the initialization phase and automatically starts a self-test program, sequentially checking the infrared receiving unit (whether it can normally receive the 38kHz carrier signal), the instruction parsing module (encoding library integrity), the security verification unit (EEPROM authorization code storage status), the local control unit (optical coupler isolation circuit continuity), and the status feedback unit (LED and infrared emitting tube validity). After the self-test passes, the green LED flashes once (lasting 0.5s), and the device enters standby mode (power consumption ≤5mA). If any module fails, the red LED stays on and records the fault code (stored in the Flash memory of the linkage protection module), awaiting manual repair.

[0036] The maintenance personnel operate the infrared remote control 9 and press the "Maintenance Trip" button. The remote control sends an infrared signal (38kHz carrier, lasting 100ms) containing the device address code (8 bits), authorization code (8 bits), trip valid command code, and check code (8 bits). The infrared receiving unit 1 captures the signal through a photoelectric sensor, filters out environmental interference through the filtering circuit 102, and amplifies the signal to TTL level before transmitting it to the command parsing module 2. The parsing module completes decoding within 5ms, verifies data integrity through CRC16 check, and proceeds to the next step only if the command code is valid; otherwise, it is considered an invalid signal and discarded.

[0037] Upon entering the security verification phase, instruction parsing module 2 extracts the authorization code, and security verification unit 3 reads 10 pre-stored encrypted authorization codes (after AES-128 decryption) from the AT24C02 EEPROM via the I²C interface and compares them (allowing a 1-bit error). If a match is successful, the authorization verification is passed, taking ≤10ms; if a mismatch occurs, "authorization error" is recorded, status feedback unit 8 drives the green LED to remain constantly lit, and the process ends. The security verification unit communicates with remote signaling unit 4 and telemetry unit 5 via the SPI interface to obtain real-time status: ① The opening / closing status fed back by the remote signaling unit must be "closed in place"; ② The line current collected by the telemetry unit must be ≤10% of the rated current (avoiding opening under load); ③ The fault indicator must have no short-circuit / ground fault signal. When all conditions are met, a "opening allowed" high-level signal (3.3V) is output, with a total time ≤25ms; if any condition is not met, "status abnormal" is recorded, the green LED remains constantly lit, and the process ends.

[0038] After receiving the "permit to open" signal, the local control unit 6 triggers the optocoupler isolation circuit (isolation voltage ≥2500Vrms) to generate a 15ms DC pulse signal (24V, 1.5A), which is transmitted to the control unit of the electromagnetic drive mechanism 7. A reverse current is applied to the electromagnetic coil, canceling the magnetic field of the neodymium iron boron magnet, and the spring force drives the moving and stationary contacts to open. Simultaneously, the linkage protection module 10 sends a "local operation in progress" signal to the main control unit 11, locking the remote opening command (for 5 minutes, or until a "maintenance complete" command is received) to prevent operational conflicts.

[0039] The remote signaling unit 4 monitors the contact position in real time. If it reports "opening in place" within 35ms (compliant with the design of the electromagnetic drive mechanism's opening time ≤ 35ms), the status feedback unit 8 activates the infrared transmitter to send a 40kHz confirmation signal (lasting 500ms). The device's red LED flashes 3 times (on for 1 second, off for 1 second). The infrared remote control 9 receives the signal, beeps 3 times, and displays "Opening successful." If the opening fails to complete within the time limit (e.g., due to mechanical jamming), the status feedback unit sends a failure code, the green LED remains constantly lit, and the remote control displays "Opening failed" and prompts the user to check the device.

[0040] After successful tripping, the linkage protection module 10 writes the operation information (timestamp accurate to milliseconds, authorization code, and current values ​​before and after tripping) into a 1MB Flash memory (supporting 100,000 erase / write cycles) and uploads it to the master station via the communication unit. After the maintenance work is completed, the maintenance personnel send a "maintenance complete" command via remote control, the linkage protection module releases the remote control lock, and the equipment returns to normal three-remote function mode.

[0041] When maintenance personnel need to perform on-site repairs, drop-out fuses also support manual drop-out for direct tripping, ensuring the safety of maintenance personnel.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An infrared control based field maintenance self-blanking system for a drop-out fuse, characterized in that, It comprises an infrared receiving unit, an instruction analysis module, a security verification unit, a local control unit and a state feedback unit connected in sequence. The infrared receiving unit receives the on-site infrared opening command. The instruction analysis module decodes and identifies the exclusive opening command. The security verification unit verifies the authority and state. The local control unit triggers the electromagnetic drive mechanism to execute opening. The state feedback unit returns the operation result.

2. The infrared control based field maintenance anti-pop system for a drop-out fuse as claimed in claim 1, wherein, The infrared receiving unit adopts 38 kHz carrier frequency, the receiving angle is ≥60°, the effective receiving distance is 5-10 m, and a filter circuit is included to eliminate infrared interference.

3. The infrared control based field maintenance anti-pop system for a drop-out fuse as claimed in claim 1, wherein, The instruction analysis module has an infrared code library built-in, only recognizes the "maintenance opening" exclusive command, and the analysis content includes 8-bit operation authority code and 16-bit opening confirmation code.

4. The infrared control based field maintenance anti-pop system for a drop-out fuse as claimed in claim 1, wherein, The security verification unit includes authority verification and state verification, and allows opening after double verification.

5. The infrared control based field maintenance anti-pop system for a drop-out fuse as claimed in claim 1, wherein, The local control unit outputs a 15 ms pulse command through an optical coupling isolation interface, controls the electromagnetic coil to input a reverse current to trigger opening.

6. The infrared control based field maintenance anti-pop system for a drop-out fuse as claimed in claim 1, wherein, The state feedback unit feeds back the opening success or failure state through a 40 kHz infrared response signal and a state indicator light.

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