A low-power intelligent fuse monitoring device

Abstract

This application relates to the field of power system distribution equipment status monitoring and fault alarm technology, specifically to a low-power intelligent fuse monitoring device, including a collection terminal and three acquisition units. The acquisition units are installed on the fuse tubes of phases A, B, and C, respectively, drawing power from a current transformer (CT) and measuring the current to detect protection events. They are equipped with vibration and attitude sensors to monitor the drop-out action of the drop-out fuse or changes in the fuse tube's attitude. The collection terminal is powered by 220V AC and equipped with a backup battery. When a preset emergency event occurs, the collection terminal sends an SMS alarm to the on-duty personnel. The acquisition units communicate bidirectionally with the collection terminal via 433MHz, and the collection terminal communicates with the main station via a 4G / 5G communication module. This application ensures critical functions under conditions of insufficient low-current power intake by switching between a supercapacitor and a backup battery, reducing missed alarms due to power failure. It also significantly reduces power consumption through domain-based gating and sleep strategies, meeting the requirements for long-term online monitoring.

Description

Technical Field

[0001] This application relates to the field of power system distribution equipment status monitoring and fault alarm technology, specifically to a low-power intelligent fuse monitoring device. Background Technology

[0002] Fuses, especially drop-out fuses, are widely used in distribution substations and low-voltage lines for overcurrent protection and isolation. In existing technology, the operating status and operation events of fuses largely rely on manual inspections or on-site confirmation after a fault, which has the following shortcomings: 1. The status is not visible and the positioning is slow. After the fuse blows, it is necessary to manually confirm the blown phase, the blown position, and whether it is a drop-induced action, which makes fault location and power restoration take a long time.

[0003] 2. The lack of a stable power supply on site makes long-term reliable operation of online monitoring difficult, and fuse installation points often lack stable auxiliary power supply. Battery power supply has high maintenance costs; CT energy extraction is insufficient under low current conditions, which can easily lead to terminal power failure, data loss, or missed alarms.

[0004] 3. The transient characteristics of the event are obvious, and key evidence is easily lost. Fault events such as overcurrent and instantaneous failure occur quickly and last for a short time. If the terminal is in sleep mode, power supply is interrupted, or communication packets are lost, it is often impossible to fully capture the fault current characteristics and waveform evidence, which affects the analysis and determination of responsibility.

[0005] 4. Insufficient communication link reliability and uncertain alarm arrival: Low-power wireless (e.g., 433MHz) in the field is susceptible to interference, collisions, and packet loss; cellular networks (4G / 5G) may experience weak coverage or congestion, leading to delays. If alarms rely on only a single path, their arrival is easily uncertain.

[0006] 5. Increased requirements for remote operation and maintenance and security: Terminals need to support remote parameter configuration, log traceability and firmware upgrades, and should have basic security mechanisms to reduce the risks of accidental access, tampering and unauthorized operation.

[0007] Therefore, there is an urgent need for an intelligent terminal device that can still monitor fuse / drop status, reliably report protection events, record key waveforms, transmit alarms from the main station, and send alarms via SMS under conditions of unstable CT power supply and limited power consumption. Summary of the Invention

[0008] This application provides a low-power intelligent fuse failure monitoring device to solve or partially solve the problems mentioned in the background art.

[0009] This application provides a low-power intelligent fuse monitoring device, characterized in that it includes a collection terminal and three acquisition units; Acquisition Unit: Installed in the fuse tubes of phases A, B, and C respectively, it draws power from the CT and measures the current, detects protection events, and is equipped with vibration attitude sensors to monitor the drop action of the drop-out fuse or the attitude change of the fuse tube. Aggregator Terminal: Powered by 220V AC and equipped with a backup battery, the aggregation terminal sends an SMS alarm to the on-duty personnel when a preset emergency occurs; The acquisition unit communicates bidirectionally with the aggregation terminal via 433MHz, and the aggregation terminal communicates with the main station via a 4G / 5G communication module.

[0010] Preferably, the acquisition unit includes: a CT energy harvesting device, a supercapacitor, a backup battery, a power management circuit, an MCU control module, a current sampling module, a vibration attitude sensor and its gate switch, a 433 communication module and its gate switch, and a hardware trigger wake-up circuit. The aggregation terminal includes an AC input and power management module, a backup battery, a 433 communication module, a main control and cache module, a 4G / 5G communication module, and an SMS alarm module.

[0011] Preferably, the power management circuit of the acquisition unit adopts an energy conversion architecture of first regulating voltage and then bucking voltage to achieve low-power power supply and energy harvesting, as follows: The CT sensing voltage is rectified and regulated to form a preset bus voltage, and then converted into the system operating voltage via DC-DC converter; The vibration sensor and the 433 communication chip are powered on / off via a domain-gated switch. When the CT power supply is insufficient, the power management circuit automatically switches to backup battery power. When the CT power supply is restored and the switching back condition is met, the power supply is switched back to the backup battery. Anti-jitter and delayed switching back strategies are set to avoid frequent switching.

[0012] Preferably, the anti-shake and delayed back-cut strategy is as follows: The switching criterion is based on the bus voltage or the supercapacitor voltage. The switching criterion must be met for a period of time exceeding a preset duration. After resuming power acquisition, there is a delay before switching back, and the supercapacitor can be recharged before high-frequency communication is restored.

[0013] Preferably, the acquisition unit achieves reliable reporting of events through event triggering and hardware wake-up, as follows: The acquisition unit adopts a sleep-wake mechanism: the MCU control module sleeps according to a preset cycle and wakes up periodically to perform current and attitude acquisition and send summary data to the collection terminal; the 433 communication module can send data at low-frequency heartbeat intervals. When emergency protection events such as overcurrent, instantaneous trip, and dropout are detected, the acquisition unit immediately activates the 433 communication module to report the event, and adopts a retransmission mechanism. After receiving the event, the aggregation terminal returns an acknowledgment to the acquisition unit, and the acquisition unit retransmits when no acknowledgment is received. The event message can carry the acquisition unit identifier, phase, event type, event sequence number, and timestamp, and the aggregation terminal completes event deduplication and traceability based on this. A hardware trigger wake-up circuit independent of the main loop of the MCU control module is set up. When the primary side current suddenly increases to reach the threshold, the MCU control module is forcibly awakened through the IO.

[0014] Preferably, the acquisition unit has the capabilities of dual-range current sampling and cycle recording, specifically as follows: To reduce the volume, the CT sampling coil supporting the acquisition unit has only one output. Therefore, the acquisition unit sets up a dual-channel current sampling link: Measurement channel: used for high-resolution measurement of a smaller range. Event channel: used for fault capture of a larger range. When the trigger condition of the event channel is met, the acquisition unit performs cycle waveform recording, and sends the waveform data in packets to the aggregation terminal via 433, and then the aggregation terminal uploads it to the main station via 4G / 5G for analysis.

[0015] Preferably, the aggregation terminal uploads data based on a hierarchical alarm routing of main station upload + SMS direct access, specifically as follows: The aggregation terminal executes different alarm strategies according to the event priority: for high-priority events such as instantaneous trip and dropout, in addition to uploading to the main station, it also sends SMS to the duty personnel to achieve direct alarm and skip redundant paths; for events such as overload and general overcurrent, it only uploads to the main station or uploads according to the configured strategy.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: This application ensures key functions through the switching between supercapacitors and backup batteries under the condition of insufficient small-current energy harvesting, reducing power-off false alarms; significantly reducing power consumption through domain gating and sleep strategies to meet long-term online monitoring; improving the capture success rate of emergency fault events through hardware forced wake-up; enhancing communication reliability through event confirmation retransmission, deduplication, and cache retransmission; enhancing event traceability and analysis value through dual-range sampling and cycle recording; and achieving alarm redundancy through SMS direct access and main station upload to improve the operation and maintenance response efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following further illustrates this application in conjunction with the drawings and embodiments.

[0018] Figure 1 It is the schematic diagram of the overall system structure of this application. Figure 2 This is a schematic diagram of the acquisition unit structure in this application. Figure 3 This is a schematic diagram of the aggregation terminal structure of this application. Figure 4 This is a schematic diagram of the power management and power supply switching of the data acquisition unit. Figure 5 This is a flowchart of the hibernation / wake-up and event handling process. Figure 6 Flowchart for event reporting confirmation and retransmission. Figure 7 This is a schematic diagram of dual-channel range sampling. Figure 8 A flowchart for recording and transmitting Zhou Bo. Detailed Implementation

[0019] The specification and claims use certain terms to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element 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 this application.

[0021] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] Example 1 like Figure 1As shown, this application provides a low-power intelligent fuse monitoring device, specifically including: a collection terminal and three acquisition units; Acquisition Unit: Installed in the fuse tubes of phases A, B, and C respectively, it draws power from the CT and measures the current, detects protection events, and is equipped with vibration attitude sensors to monitor the drop action of the drop-out fuse or the attitude change of the fuse tube. Aggregator Terminal: Powered by 220V AC and equipped with a backup battery, the aggregation terminal sends an SMS alarm to the on-duty personnel when a preset emergency occurs; The acquisition unit communicates bidirectionally with the aggregation terminal via 433MHz, and the aggregation terminal communicates with the main station via a 4G / 5G communication module.

[0023] like Figure 2 As shown, the acquisition unit includes: a CT energy harvesting device, a supercapacitor, a backup battery, a power management circuit, an MCU control module, a current sampling module, a vibration attitude sensor and its gate switch, a 433 communication module and its gate switch, and a hardware trigger wake-up circuit.

[0024] like Figure 3 As shown, the aggregation terminal includes an AC input and power management module (220V), a backup battery, a 433 communication module, a main control and cache module, a 4G / 5G communication module, and an SMS alarm module. The 433 communication module is used for sending and receiving data with the acquisition unit and for ACK confirmation. The main control and cache module is used for event deduplication, cache retransmission, and logging. The 4G / 5G communication module is used for communication with the main station. The SMS alarm module can be set up independently or integrated into the 4G / 5G communication module.

[0025] Specifically, the power management circuit of the acquisition unit adopts an energy conversion architecture of first regulating and then bucking the voltage to achieve low-power power supply and energy harvesting, as follows: The CT sensing voltage is rectified and regulated to form a preset bus voltage (e.g., 12V), and then converted to the system operating voltage (e.g., 3.3V) via DC-DC converter to improve energy harvesting efficiency and stabilize power supply. Compared with LDO circuits, DC-DC conversion can achieve energy conversion more efficiently. By using a domain-gated switch to control the power-on / power-off of the vibration sensor and the 433 communication chip, the static power consumption is negligible when not in operation. When the CT power supply is insufficient (e.g., low current), the power management circuit automatically switches to backup battery power. When the CT power supply recovers and the cut-off conditions are met, it switches back to power supply. Anti-jitter and delayed cut-off strategies can be set to avoid frequent switching.

[0026] like Figure 4In the implementation example shown, the acquisition unit obtains energy through the CT. Since the open-circuit induced voltage of the CT is high, in order to improve the energy extraction efficiency, the voltage is first stabilized to the intermediate bus voltage (e.g., 12V), and then through DC-DC conversion. The supercapacitor is used for short-term energy storage and pulse load support. When the bus energy is insufficient, it automatically switches to the backup battery power supply. To avoid frequent power switching at critical points, one or a combination of the following control strategies can be used: The switching criterion is based on the bus voltage or the supercapacitor voltage. The switching criterion must be met for a period of time exceeding a preset duration. After resuming power acquisition, there is a delay before switching back, and the supercapacitor can be recharged before high-frequency communication is restored.

[0027] Specifically, the acquisition unit achieves reliable event reporting through event triggering and hardware wake-up, as follows: The acquisition unit adopts a sleep-wake mechanism: the MCU control module sleeps according to a preset cycle and wakes up at regular intervals (e.g., 60 seconds) to perform current and attitude acquisition and send summary data to the collection terminal; the 433 communication module can send data at low-frequency heartbeat intervals (e.g., 10 seconds) to save energy; When an emergency protection event such as overcurrent, instantaneous interruption, or drop is detected, the acquisition unit immediately activates the 433 communication module to report the event and adopts a retransmission mechanism. After receiving the event, the aggregation terminal sends an acknowledgment to the acquisition unit. If the acquisition unit does not receive an acknowledgment, it retransmits the event, thereby improving the reporting success rate in interference environments. Event messages can carry the collection unit identifier, phase, event type, event sequence number and timestamp, which the collection terminal uses to complete event deduplication and tracing.

[0028] The acquisition unit is equipped with a hardware trigger wake-up circuit that is independent of the main loop of the MCU control module. When the primary current suddenly increases to the threshold, the MCU control module is forcibly woken up through IO to ensure that fault current and events can still be captured in a timely manner during the MCU sleep period.

[0029] like Figure 5 As shown, this is an example of the sleep / wake-up and event handling of the acquisition unit. In normal state, the acquisition unit adopts a periodic sleep strategy. The MCU control module wakes up periodically (e.g., every 60 seconds), completes current measurement and attitude sampling, and sends data once before entering sleep mode. The vibration sensor and the 433 communication module are powered off by a gate switch during non-working windows. In the event of an emergency, the acquisition unit immediately enters the event handling process, activates the 433 module to send event messages and performs confirmation retransmission, and starts cycle recording if necessary.

[0030] like Figure 6As shown in the figure, it is an example of event reporting confirmation retransmission and deduplication processing. The fields carried by the event message collected by the collection unit at least include: collection unit ID, phase, event type, event sequence number, and timestamp. After the collection unit sends an event, it waits for confirmation from the aggregation terminal. If not confirmed, it will be resent until the upper limit of the number of times is reached or the confirmation is successful; The aggregation terminal deduplicates the event sequence numbers and returns the confirmation information to the collection unit. The aggregation terminal creates a deduplication record for the received event messages according to "collection unit ID + event sequence number", and within the preset time window, only returns confirmation for duplicate events without triggering text messages repeatedly. For the same event type exceeding the time window, text messages can be triggered again according to the policy or only sent to the master station.

[0031] Specifically, the collection unit has the capabilities of dual-range current sampling and cycle recording, as follows: In order to reduce the volume, the CT sampling coil supporting the collection unit has only one output. Therefore, the collection unit sets up a dual-channel current sampling link: [[ID=**8]] Measurement channel: used for high-resolution measurement of a smaller range (such as 0 - 100A); Event channel: used for fault capture of a larger range (such as 0 - 1000A); When the trigger condition of the event channel is met, the collection unit performs cycle waveform recording (such as 10 cycles), and分包 the waveform data and sends it to the aggregation terminal via 433. Then, the aggregation terminal uploads it to the master station via 4G / 5G for analysis.

[0032] As Figure 7 shown in the figure, it is a schematic diagram of the link for the collection unit to distribute the same CT signal to two channels of conditioning and sampling: The collection unit connects the CT secondary side outputs of the current sampling module to the measurement channel conditioning circuit and the event channel conditioning circuit respectively. The two conditioning circuits include input limiting / clamping protection, gain configuration, and filtering units; The measurement channel is used to obtain the daily current value with higher resolution, and the event channel is used to obtain the fault current sampling with a wider dynamic range and is used to trigger events and the recording and wave analysis process. The two channels sample independently to balance the measurement accuracy and fault capture ability, where Measurement channel: for example, used for 0 - 100A measurement; Event channel: for example, used for 0 - 1000A fault capture.

[0033] As Figure 8 shown in the figure, it is an example of cycle recording. When the trigger condition of the event channel is met (such as: large sampling current), the collection unit performs cycle recording (such as 10 cycles), and分包 the waveform data and sends it to the aggregation terminal. The aggregation terminal caches it and uploads it to the master station via 4G / 5G.

[0034] Specifically, the aggregation terminal uploads data based on a hierarchical alarm routing system that combines data sent from the main station and data sent directly via SMS, as detailed below: The aggregation terminal executes different alarm strategies based on event priority: for high-priority events such as instantaneous interruption and drop, in addition to sending the alarm to the main station, it also sends an SMS to the on-duty personnel to achieve direct alarm delivery and skip redundant paths; for events such as overload and general overcurrent, it only sends the alarm to the main station or sends the alarm according to the configured strategy.

[0035] Specifically, the events include: overload, overcurrent, instantaneous interruption, and drop. The event criteria are configurable, and typical event criteria are as follows: Fuse overload event: A current of 50A or more lasting for 1 minute is considered an overload. Instantaneous tripping event of fuse: When the current reaches or exceeds 200A, it is immediately determined as instantaneous tripping (0-second trigger, that is, the process is triggered immediately upon detection). Fuse overcurrent event: A combination of threshold and duration between overload and instantaneous trip, configurable according to site requirements; Fuse drop event: Determined when the attitude change characteristics of the drop-out action of the drop-out fuse are detected, or when the current event and attitude characteristics meet the conditions.

[0036] The alarm routing policy for the aggregation terminal is as follows: Instantaneous interruption / fall: Triggers an SMS alarm to the on-duty personnel and simultaneously sends it to the main station; Overload, overcurrent: Send to the main station (whether to include waveform summary can be determined by configuration).

[0037] This application utilizes a combination of power harvesting-storage-backup power switching and a low-power sleep strategy to enable the acquisition unit to maintain event detection and reporting capabilities even when power harvesting is insufficient due to low current, and to suppress frequent switching under critical operating conditions. Hardware-triggered forced wake-up and wide-range sampling of the event channel ensure that the MCU can be promptly woken up and enter the event acquisition and reporting process even when encountering a large current surge during sleep. The combination of event sequence number / timestamp + acknowledgment retransmission + deduplication with the 433 link improves the event delivery rate under interference environments and avoids duplicate alarms. The combination of dual-range channels + cycle recording + aggregation and forwarding achieves a balance between daily measurement accuracy and the dynamic range of fault capture, and reliably transmits waveform evidence to the main station. Event hierarchical routing, with SMS triggered by rapid failure / drop, and normal device monitoring information transmitted to the main station, combined with the cellular communication capabilities of the aggregation terminal, achieves alarm redundancy and rapid response, improving maintenance response efficiency.

[0038] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A low-power intelligent fuse failure monitoring device, characterized in that, It includes a collection terminal and three acquisition units; Acquisition Unit: Installed in the fuse tubes of phases A, B, and C respectively, it draws power from the CT and measures the current, detects protection events, and is equipped with vibration attitude sensors to monitor the drop action of the drop-out fuse or the attitude change of the fuse tube. Aggregator Terminal: Powered by 220V AC and equipped with a backup battery, the aggregation terminal sends an SMS alarm to the on-duty personnel when a preset emergency occurs; The acquisition unit communicates bidirectionally with the aggregation terminal via 433MHz, and the aggregation terminal communicates with the main station via a 4G / 5G communication module.

2. The low-power intelligent fuse monitoring device according to claim 1, characterized in that: The acquisition unit includes: a CT energy harvesting device, a supercapacitor, a backup battery, a power management circuit, an MCU control module, a current sampling module, a vibration attitude sensor and its gate switch, a 433 communication module and its gate switch, and a hardware trigger wake-up circuit. The aggregation terminal includes an AC input and power management module, a backup battery, a 433 communication module, a main control and cache module, a 4G / 5G communication module, and an SMS alarm module.

3. The low-power intelligent fuse monitoring device according to claim 2, characterized in that: The power management circuit of the acquisition unit adopts an energy conversion architecture of first regulating and then bucking to achieve low-power power supply and energy harvesting, as detailed below: The CT sensing voltage is rectified and regulated to form a preset bus voltage, and then converted into the system operating voltage via DC-DC converter; The vibration sensor and the 433 communication chip are powered on / off via a domain-gated switch. When the CT power supply is insufficient, the power management circuit automatically switches to backup battery power. When the CT power supply is restored and the switching back condition is met, the power supply is switched back to the backup battery. Anti-jitter and delayed switching back strategies are set to avoid frequent switching.

4. The low-power intelligent fuse failure monitoring device according to claim 3, characterized in that: The specific anti-shake and delayed back-cut strategies are as follows: The switching criterion is based on the bus voltage or the supercapacitor voltage. The switching criterion must be met for a period of time or longer than a preset time. After resuming power acquisition, there is a delay before switching back, and the supercapacitor can be recharged before high-frequency communication is restored.

5. The low-power intelligent fuse monitoring device according to claim 2, characterized in that: The acquisition unit achieves reliable event reporting through event triggering and hardware wake-up, as detailed below: The acquisition unit adopts a sleep-wake mechanism: the MCU control module sleeps according to a preset cycle and wakes up periodically to perform current and attitude acquisition and send summary data to the collection terminal; the 433 communication module can send data at low-frequency heartbeat intervals. When an emergency protection event such as overcurrent, instantaneous interruption, or drop is detected, the acquisition unit immediately activates the 433 communication module to report the event and adopts a retransmission mechanism. After receiving the event, the aggregation terminal returns an acknowledgment to the acquisition unit, and the acquisition unit retransmits the event if it does not receive an acknowledgment. Event messages can carry the collection unit identifier, phase, event type, event sequence number and timestamp, which the collection terminal uses to complete event deduplication and tracing; A hardware trigger wake-up circuit independent of the main loop of the MCU control module is set up. When the primary side current suddenly increases to reach the threshold, the MCU control module is forcibly woken up through the IO.

6. A low-power intelligent fusing monitoring device according to claim 2, wherein: The acquisition unit has the capabilities of dual-range current sampling and cycle recording, specifically as follows: To reduce the volume, the CT sampling coil supporting the acquisition unit has only one output. Therefore, the acquisition unit sets up a dual-channel current sampling link: Measurement channel: used for high-resolution measurement in a smaller range; Event channel: used for fault capture in a larger range; When the trigger condition of the event channel is satisfied, the acquisition unit performs cycle waveform recording, and the waveform data is packetized and sent to the aggregation terminal via 433. Then, the aggregation terminal uploads it to the master station via 4G / 5G for analysis.

7. A low-power intelligent fusing monitoring device according to claim 2, wherein: The aggregation terminal uploads data based on a hierarchical alarm routing of master station upload + SMS direct access, specifically as follows: The aggregation terminal executes different alarm strategies according to the event priority: for high-priority events such as quick-break and drop, in addition to uploading to the master station, it also sends SMS to the duty personnel to achieve direct alarm and skip redundant paths; for events such as overload and general overcurrent, it only uploads to the master station or uploads according to the configured strategy.

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