Intelligent feeder terminal equipment with automatic power supply switching function

Abstract

The invention relates to intelligent feeder terminal equipment with an automatic power supply switching function, which comprises an intelligent detection module, a fault diagnosis module, an automatic switching control module and a load protection module, and is characterized in that the intelligent detection module comprises a voltage sensor and a current sensor, and power supply signals are acquired through the voltage sensor and the current sensor; the fault diagnosis module checks fault points based on the electric signals in combination with a fault tree algorithm; the automatic switching control module realizes switching from the main power supply to the standby power supply or switching from the standby power supply to the main power supply according to the output switching instruction; the load protection module comprises a multi-stage protection circuit and a linkage lockout circuit, when a load is short-circuited, a load fault signal is sent to the intelligent detection module, power supply switching is forbidden, and after the fault is removed and the intelligent detection module confirms that the power supply is normal, automatic reclosing is supported. According to the invention, a closed-loop control system of'detection-diagnosis-switching-protection 'is formed, and the problem of traditional FTU control flow splitting is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system distribution automation, and in particular to an intelligent feeder terminal device with an automatic power supply switching function. Background Art

[0002] As the core equipment of the distribution automation system, the feeder terminal (FTU) is deployed on outdoor pole switches and undertakes key functions such as line status monitoring, fault analysis and remote control. However, the outdoor environment is full of complex conditions such as lightning strikes, power grid fluctuations, and extreme temperatures. Traditional FTUs have gradually exposed many pain points during operation: (1) Shortcomings in power supply reliability: They mostly rely on a single power supply mode such as voltage transformer power supply. Once the power supply fails, the equipment will lose power, which will directly cause the distribution network monitoring and control process to be interrupted, greatly prolonging the fault recovery time and posing a threat to the stable operation of the distribution system; (2) Switching logic defects: The existing dual power switching mechanism only performs switching based on the simple logic judgment of "power on / power off", and does not fully consider voltage quality factors. Conditions such as undervoltage and harmonics are not included in the judgment, which can easily cause incorrect switching or (1) The single dimension of judgment leads to untimely switching and inability to adapt to the precise power supply requirements under complex power grid conditions; (2) Lack of load coordinated protection: The power switching system and the load protection device operate independently of each other. When a short circuit fault occurs in the load, the risk of fault spread remains high, which will not only damage the equipment itself, but also affect the service life of the line, increase operation and maintenance costs and safety hazards; (3) Lack of load coordinated protection: The power switching system and the load protection device operate independently of each other. When a short circuit fault occurs in the load, the risk of fault spread remains high, which will not only damage the equipment itself, but also affect the service life of the line, increase operation and maintenance costs and safety hazards; (4) Fault diagnosis lag: The fault location link relies heavily on manual troubleshooting. From fault discovery to location and repair, it takes a long time, and the operation and maintenance efficiency is extremely low, which further prolongs the power outage time and has an adverse impact on the normal power consumption of power users and the reliable power supply of the distribution system.

[0003] In summary, although existing technologies involve dual power switching, none of them have built a closed-loop control system of "intelligent perception-precise switching-coordinated protection-self-diagnosis". They are unable to meet the stringent requirements of outdoor distribution networks for high reliability and cannot effectively respond to various power supply challenges in complex environments. Therefore, it is extremely necessary to innovate and optimize the FTU power switching and protection mechanism. Summary of the Invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the technical defects of the existing technology and propose an intelligent feeder terminal device with automatic power switching function. Through the closed-loop control system of "detection-diagnosis-switching-protection", it solves the problem of fragmentation of traditional FTU control process and meets the high reliability requirements of distribution network in complex outdoor environments.

[0005] To solve the above technical problems, the present invention provides an intelligent feeder terminal device with an automatic power supply switching function, comprising:

[0006] An intelligent detection module, comprising a voltage sensor and a current sensor, which collect power supply signals and convert them into recognizable electrical signals after signal conditioning;

[0007] Fault diagnosis module, which uses electrical signals combined with fault tree algorithm to identify the fault point and output switching instructions according to the fault point;

[0008] an automatic switching control module, which implements switching from the main power supply to the backup power supply, or from the backup power supply to the main power supply according to the switching instruction output by the fault diagnosis module;

[0009] The load protection module includes a multi-level protection circuit and a linkage locking circuit. When the load is short-circuited, it sends a load fault signal to the intelligent detection module to prohibit power switching. After the fault is eliminated and the intelligent detection module confirms that the power supply is normal, it supports automatic reclosing.

[0010] In one embodiment of the present invention, the intelligent detection module includes a processor and a 5G communication module, the voltage sensor is connected in parallel to the main power supply and / or backup power supply line, the voltage sensor is connected to the processor through an analog input interface, the current sensor is connected in series to the power supply circuit, the current sensor is connected to the processor through an analog input interface, and the 5G communication module is connected to the processor.

[0011] In one embodiment of the present invention, the intelligent detection module further includes a signal conditioning module, and the signal conditioning module is connected to the processor.

[0012] In one embodiment of the present invention, the fault diagnosis module is connected to the intelligent detection module via an RS485 bus, the fault code is displayed by driving the light-emitting diode through the interface, and the log storage module is installed on a PCB daughter card next to the main control board of the feeder terminal device through an external device interface expansion.

[0013] In one embodiment of the present invention, the automatic switching control module includes a dual-power automatic transfer switch, and the dual-power automatic transfer switch is installed on the power input side of the feeder terminal equipment.

[0014] In one embodiment of the present invention, the automatic switching control module automatically switches back to the main power supply after the main power supply operates normally and stably for 30 seconds.

[0015] In one embodiment of the present invention, the multi-stage protection circuit includes a short-circuit protection circuit, an overload protection circuit and a surge protection circuit. The surge protection circuit is connected in parallel to the main power input end, and the linkage lockout signal is connected to the interface of the intelligent detection module after being isolated by an optocoupler.

[0016] In one embodiment of the present invention, the short-circuit protection circuit includes a magnetic trip circuit breaker for cutting off a short-circuit circuit of ≥10 times the rated current within 10ms, and the overload protection circuit includes a thermal trip circuit breaker for cutting off a continuous overload current of 1.2 times within 2s.

[0017] The above technical solution of the present invention has the following advantages over the prior art:

[0018] The present invention provides an intelligent feeder terminal device with automatic power switching function. It collects power signals in real time through an intelligent detection module, accurately locates faults in combination with a fault tree algorithm, and quickly triggers an automatic switching control module to achieve seamless switching of the main and standby power supplies, ensuring continuous operation of the equipment, significantly shortening the fault recovery time, and forming a "detection-diagnosis-switching-protection" closed-loop control system. It solves the problem of fragmented traditional FTU control processes, meets the high reliability requirements of distribution networks in complex outdoor environments, and provides an intelligent and safe solution for distribution automation. In addition, the load protection module integrates multi-level protection circuits and a linkage locking mechanism. Power switching is prohibited in the event of a short circuit to prevent the spread of faults. After the fault is eliminated, the circuit breaker automatically recloses and restores power supply, effectively reducing the risk of equipment damage and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0020] Figure 1 The diagram is a structural diagram of an intelligent feeder terminal device with an automatic power switching function proposed in an embodiment of the present invention.

[0021] Figure 2 The figure is a hardware structure diagram of an intelligent feeder terminal device with automatic power switching function proposed in an embodiment of the present invention.

[0022] Among them, the description of the accompanying drawings is as follows: 1. Feeder terminal equipment; 2. Automatic power switching system; 21. Intelligent detection module; 22. Fault diagnosis module; 23. Automatic switching control module; 24. Load protection module. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0024] Reference Figure 1 and Figure 2As shown, an embodiment of the present invention provides an intelligent feeder terminal device 1 with an automatic power switching function, including an automatic power switching system 2, the automatic power switching system 2 including an intelligent detection module 21, a fault diagnosis module 22, an automatic switching control module 23 and a load protection module 24, the intelligent detection module 21 including a voltage sensor and a current sensor, which collects power signals through the voltage sensor and the current sensor and converts them into recognizable electrical signals after signal conditioning; the fault diagnosis module 22 detects the fault point based on the electrical signal in combination with the fault tree algorithm, and outputs a switching instruction according to the fault point; the automatic switching control module 23 implements the switching from the main power supply to the backup power supply, or the switching from the backup power supply to the main power supply according to the switching instruction output by the fault diagnosis module 22; the load protection module 24 includes a multi-stage protection circuit and a linkage locking circuit. When the load is short-circuited, a load fault signal is sent to the intelligent detection module 21 to prohibit power switching. After the fault is eliminated, after the intelligent detection module 21 confirms that the power supply is normal, it supports automatic reclosing.

[0025] The present invention provides an intelligent feeder terminal device 1 with an automatic power switching function. It collects power signals in real time through an intelligent detection module 21, accurately locates faults in combination with a fault tree algorithm, and quickly triggers an automatic switching control module 23 to achieve seamless switching of primary and standby power supplies, ensure continuous operation of the equipment, significantly shorten fault recovery time, and form a closed-loop control system of "detection-diagnosis-switching-protection". It solves the problem of fragmentation of traditional FTU control processes, meets the high reliability requirements of distribution networks in complex outdoor environments, and provides an intelligent and safe solution for distribution automation. In addition, the load protection module 24 integrates multi-level protection circuits and a linkage locking mechanism. Power switching is prohibited in the event of a short circuit to prevent the spread of the fault. After the fault is eliminated, the circuit breaker automatically recloses and restores power supply, effectively reducing the risk of equipment damage and extending its service life.

[0026] In an optional embodiment, the intelligent detection module 21 includes a processor and a 5G communication module. A voltage sensor is connected in parallel to the main power supply and / or backup power supply line, and the voltage sensor is connected to the processor via an analog input interface. A current sensor is connected in series to the power supply circuit, and the current sensor is connected to the processor via an analog input interface. The 5G communication module is connected to the processor. Specifically, the voltage sensor is connected in parallel to the main / backup power supply line to sense the line voltage in real time, convert it into an analog electrical signal, and transmit it to the processor through the analog input interface for analysis of parameters such as voltage amplitude, frequency, and harmonics; the current sensor is connected in series in the power supply circuit to detect changes in the circuit current and also transmit the analog signal to the processor via the analog input interface. The processor has a built-in AD conversion module that converts the analog signal into a digital signal and analyzes the power supply status based on a preset algorithm to determine whether there are abnormalities such as overvoltage, undervoltage, and overcurrent. The 5G communication module is connected to the processor via a communication interface such as UART, receives power data and fault information processed by the processor, encapsulates it in a 5G network protocol, and sends it to the power distribution master station. At the same time, it receives control instructions from the master station and feeds them back to the processor.

[0027] In terms of power supply monitoring, the above-mentioned intelligent detection module 21 accurately collects the voltage and current data of the main / backup power supply to provide a basis for fault diagnosis; fault warning and reporting, timely identify power supply anomalies, combine algorithms to locate faults, and quickly report to the main station through the 5G communication module, so that operation and maintenance personnel can remotely grasp them; in terms of remote interaction function, with the help of 5G communication, two-way communication between the main station and FTU is realized, remote parameter configuration and equipment status query are supported, and operation and maintenance efficiency is improved; in addition, data support is provided for functional modules such as automatic power switching and load protection to ensure that each module works together and guarantees the stable operation of the feeder terminal equipment 1FTU.

[0028] In an optional embodiment, the intelligent detection module 21 further includes a signal conditioning module, which is connected to the processor. The original analog signals collected by the voltage sensor and the current sensor have problems such as weak signals, noise interference, and level mismatch. The signal conditioning module first filters the original signals and uses low-pass and band-pass filters to remove high-frequency noise and clutter; then, the weak signal is amplified to an appropriate level (such as from mV level to V level) through an amplification circuit to ensure that the processor's ADC (analog-to-digital converter) can effectively recognize it; then, a level conversion is performed to convert the sensor output level to a level standard compatible with the processor's analog input interface; finally, the conditioned signal is transmitted to the processor, and after AD conversion and algorithm analysis, the power status data is extracted. This implementation significantly enhances the system's anti-interference capability through the signal conditioning module, reducing the voltage and current data acquisition error to within ±0.5%, effectively avoiding misjudgments due to signal distortion. It also improves sensor compatibility and can adapt to sensors with different ranges and output characteristics. It ensures the real-time and stability of data acquisition, and can still provide accurate data support for the FTU's intelligent control in complex outdoor electromagnetic environments, thereby improving equipment operation reliability and fault response efficiency.

[0029] In an optional embodiment, the fault diagnosis module 22 is connected to the intelligent detection module 21 via an RS485 bus. The fault code is displayed on a light-emitting diode (LED) through an interface. The log storage module is installed on a PCB daughter card next to the main control board of the feeder terminal device 1 via an external device interface extension. The intelligent detection module 21 collects voltage / current data in real time (sampling frequency 10kHz) and transmits it to the fault diagnosis module 22 via the RS485 bus. The fault diagnosis module 22 performs logical judgment based on a fault tree algorithm (preset 128 rules), completing a fault scan every 20ms. When an anomaly is detected (such as a voltage sag >30%), a fault code is immediately generated (such as E001 indicating a main power failure). This code is driven by an LED display and written to the log storage module via the SPI interface. The log is stored in the format of timestamp (accurate to milliseconds) + fault code + voltage / current value, with each record occupying 128 bytes. The storage module supports quick retrieval by time range and fault type, and can be queried through the OLED display (128×64 pixels) on the front panel of the FTU or a remote communication interface (such as 5G). The retrieval response time is ≤500ms, and it supports processing 3 concurrent query requests at the same time. The independent daughter card design of this embodiment enables the log storage module to withstand vibrations up to 10g, and the data retention rate is ≥99.9% within the temperature range of -40℃ to +85℃, meeting the long-term operation requirements in harsh outdoor environments. When the storage capacity needs to be expanded, only the daughter card needs to be replaced (such as 1GB→4GB) without changing the main control board design. The upgrade cost is reduced by 70%, and the upgrade time is ≤10 minutes.

[0030] In an optional embodiment, the automatic switching control module 23 includes a dual-power automatic transfer switch, which is installed on the power input side of the feeder terminal device 1. The dual-power automatic transfer switch has mechanical + electrical interlocking (to prevent two power supplies from being connected in parallel), and the switching time is ≤20ms. When the main power supply is normal (voltage 85%-115% rated value, frequency 49.5-50.5Hz, THD ≤5%), the main power supply is given priority; when the main power supply is abnormal (any parameter exceeds the limit), the "main→standby" switching is triggered, and the backup power supply (such as supercapacitor + DC converter, battery) is put into use; when the main power supply returns to normal and runs stably for 30s (to prevent frequent switching), the "standby→main" switchback is triggered. Preferably, a manual switching knob can be configured to support forced intervention by operation and maintenance personnel in the event of a fault.

[0031] In an optional embodiment, the multi-level protection circuit includes a short-circuit protection circuit, an overload protection circuit and a surge protection circuit. The surge protection circuit is connected in parallel to the main power input terminal, and the interlocking lock signal is connected to the interface of the intelligent detection module 21 after being isolated by an optocoupler. The short-circuit protection circuit includes a magnetic trip circuit breaker for cutting off a short-circuit circuit of ≥10 times the rated current within 10ms, and the overload protection circuit includes a thermal trip circuit breaker for cutting off a continuous overload current of 1.2 times within 2s. In this embodiment, surge protection resists transient overvoltages, short-circuit protection responds to sudden large currents, and overload protection handles continuous abnormal currents, forming a three-dimensional protection network of "transient suppression-instantaneous cutoff-delay protection", which effectively reduces the failure rate of the equipment. The 10ms rapid cutoff of short-circuit protection and the 2s delay design of overload protection accurately match different fault characteristics, which not only avoids false operation affecting normal power supply, but also can respond quickly in the event of a real fault.

[0032] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An intelligent feeder terminal device with automatic power switching function, characterized by: include: An intelligent detection module, comprising a voltage sensor and a current sensor, which collect power supply signals and convert them into recognizable electrical signals after signal conditioning; Fault diagnosis module, which uses electrical signals combined with fault tree algorithm to identify the fault point and output switching instructions according to the fault point; An automatic switching control module, which implements switching from the main power supply to the backup power supply, or from the backup power supply to the main power supply according to the switching instruction output by the fault diagnosis module; The load protection module includes a multi-level protection circuit and a linkage locking circuit. When the load is short-circuited, it sends a load fault signal to the intelligent detection module to prohibit power switching. After the fault is eliminated and the intelligent detection module confirms that the power supply is normal, it supports automatic reclosing.

2. The intelligent feeder terminal device with automatic power switching function according to claim 1, characterized in that: The intelligent detection module includes a processor and a 5G communication module. The voltage sensor is connected in parallel to the main power supply and / or backup power supply line, the voltage sensor is connected to the processor through an analog input interface, the current sensor is connected in series to the power supply circuit, the current sensor is connected to the processor through an analog input interface, and the 5G communication module is connected to the processor.

3. The intelligent feeder terminal device with automatic power switching function according to claim 2, characterized in that: The intelligent detection module further includes a signal conditioning module, and the signal conditioning module is connected to the processor.

4. The intelligent feeder terminal device with automatic power switching function according to claim 2, characterized in that: The fault diagnosis module is connected to the intelligent detection module through the RS485 bus, the fault code is displayed by driving the light-emitting diode through the interface, and the log storage module is installed on the PCB daughter card next to the main control board of the feeder terminal equipment through the external device interface expansion.

5. The intelligent feeder terminal device with automatic power switching function according to claim 1, characterized in that: The automatic switching control module includes a dual-power automatic transfer switch, and the dual-power automatic transfer switch is installed on the power input side of the feeder terminal equipment.

6. The intelligent feeder terminal device with automatic power switching function according to claim 1 or 5, characterized in that: The automatic switching control module automatically switches back to the main power supply after the main power supply operates normally and stably for 30 seconds.

7. The intelligent feeder terminal device with automatic power switching function according to claim 1, characterized in that: The multi-level protection circuit includes a short-circuit protection circuit, an overload protection circuit and a surge protection circuit. The surge protection circuit is connected in parallel to the main power input terminal, and the linkage lockout signal is connected to the interface of the intelligent detection module after being isolated by an optical coupler.

8. The intelligent feeder terminal device with automatic power switching function according to claim 6, characterized in that: The short-circuit protection circuit includes a magnetic trip circuit breaker for cutting off a short-circuit loop of ≥10 times the rated current within 10ms, and the overload protection circuit includes a thermal trip circuit breaker for cutting off a continuous overload current of 1.2 times within 2s.

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