A power transformation and distribution cabinet door state monitoring device integrated with sound and light alarm

Abstract

The application relates to the technical field of power equipment security and protection, in particular to a power transformation and distribution cabinet door state monitoring device integrated with an audible and light alarm, which comprises a multi-modal sensing module, a main control processing module, an audible and light alarm module, a self-adaptive wireless communication module and a maintenance power supply module; the multi-modal sensing module collects cabinet door displacement, mechanical impact and live state data, the main control processing module performs space-time alignment and logical correlation on the data to determine the nature of the cabinet door opening behavior, the audible and light alarm module executes a hierarchical warning strategy accordingly, the self-adaptive wireless communication module dynamically adjusts the radio frequency transmission power according to the cabinet door state, and the maintenance power supply module uses a super capacitor for uninterrupted power supply when the main power supply is powered off. The application can effectively distinguish illegal prying, abnormal accidental touch and normal maintenance state, reduce the false alarm rate, reduce the electromagnetic radiation exposure of operating personnel, and ensure the continuous operation of the monitoring and alarm functions under the power-off working condition.

Description

Technical Field

[0001] This invention relates to the field of power equipment security technology, and in particular to a transformer substation door status monitoring device with integrated audible and visual alarms. Background Technology

[0002] As a critical node in the power system, the operating status of switchgear directly affects the safety, stability, and reliability of the power grid. In substations, distribution rooms, and other similar settings, real-time monitoring of switchgear door status is crucial for preventing unauthorized intrusion, ensuring maintenance safety, and preventing electrical accidents. Existing switchgear door status monitoring technologies typically employ single mechanical limit switches or magnetic sensors to detect the open / closed position of the door. Some advanced systems incorporate simple wireless transmission capabilities, uploading switch signals to a monitoring center. These solutions determine whether the door is open by detecting changes in magnetic fields or the continuity of physical contact, triggering basic alarm prompts or data reports upon detecting an open signal, thus forming a fundamental component of the current security system for power distribution facilities.

[0003] In existing technologies, due to the lack of ability to fuse and analyze multi-dimensional state information, it is difficult to accurately distinguish the specific nature of cabinet door opening. As a result, when faced with complex on-site working conditions, it is impossible to effectively identify the differences between illegal prying, abnormal accidental touch and normal inspection behavior, which can easily lead to false alarms or missed alarms, or monitoring function failure under extreme working conditions such as power outages. Summary of the Invention

[0004] The purpose of this invention is to provide a power distribution cabinet door status monitoring device with integrated audible and visual alarms, which can solve the technical problems in the prior art of being unable to accurately distinguish the nature of cabinet door opening behavior and the failure of monitoring function under power failure conditions.

[0005] This application provides a transformer substation door status monitoring device with integrated audible and visual alarm, comprising: The multimodal sensing module is configured to collect multidimensional status data of the power distribution cabinet. The multimodal sensing module includes a Hall gate magnetic sensor for detecting the displacement of the cabinet door, a vibration sensor for detecting the mechanical impact signal of the cabinet door, and a voltage detection interface for obtaining the energized state of the cabinet. The main control processing module is connected to the multimodal sensing module, the audible and visual alarm module, the adaptive wireless communication module and the power supply module respectively. The main control processing module is configured to perform spatiotemporal alignment and logical association of displacement, mechanical impact signal and electrical status in multidimensional status data in order to determine whether the cabinet door opening behavior belongs to illegal prying state, abnormal accidental touch state or normal maintenance state. The audible and visual alarm module is configured to execute a tiered warning strategy based on the status judgment result output by the main control processing module. The tiered warning strategy includes: when it is determined to be an illegal prying state and the cabinet is energized, a high-frequency flashing light and a rapid buzzer are triggered; when it is determined to be an abnormal accidental touch state, a constant light and a single tone are triggered. The adaptive wireless communication module is configured to dynamically adjust the radio frequency transmission power according to the cabinet door status output by the main control processing module. Specifically, it includes: when the cabinet door is detected to be closed, periodic heartbeat data is transmitted at a first transmission power; when the cabinet door is detected to be open, the transmission power is reduced to a second transmission power lower than a preset safety threshold to reduce electromagnetic radiation exposure to personnel working at close range, and the transmission power is restored to the first transmission power after the cabinet door is closed again. The power supply module includes an energy harvesting unit, a supercapacitor energy storage unit, and a power management circuit. The energy harvesting unit is configured to draw power from the busbar inside the cabinet or collect auxiliary power. The power management circuit is configured to control the supercapacitor energy storage unit to provide uninterrupted power to the device when the voltage detection interface detects that the cabinet has lost power.

[0006] The Hall effect sensor includes a Hall element fixed to the side of the cabinet door and a permanent magnet fixed to the cabinet door frame; the vibration sensor is a piezoelectric vibration sensor or a microelectromechanical system accelerometer, which is attached to the surface of the metal plate inside the cabinet door; the voltage detection interface is electrically connected to the busbar or live display device in the power distribution cabinet through a high-voltage step-down isolation circuit.

[0007] The specific logic for the main control processing module to determine cabinet door opening behavior is as follows: If the vibration sensor detects a mechanical impact signal exceeding the first set threshold within the preset first time window, and the Hall effect sensor detects the displacement of the cabinet door, it is determined to be an illegal prying state. If the Hall effect sensor detects the displacement of the cabinet door, but the vibration sensor does not detect a mechanical impact signal or the mechanical impact signal is below the second set threshold, and no legitimate identity authentication signal is received, then it is determined to be an abnormal false touch state. If it does not fall into either of the above two categories, it is determined to be in normal maintenance condition.

[0008] The sound and light alarm module includes a high-brightness multi-color LED array, a piezoelectric high-frequency buzzer, and a sound and light driving circuit. When the main control processing module outputs a normal maintenance status, the sound and light alarm module executes a silent strategy or triggers a low-frequency breathing light indicator to indicate that it is currently in authorized maintenance mode.

[0009] The adaptive wireless communication module includes a long-range wide area network module and a short-range low-power Bluetooth module. When the cabinet door is detected to be open, the main control processing module shuts down the radio frequency front-end of the long-range wide area network module and activates the short-range low-power Bluetooth module to establish an encrypted local communication link with the portable terminal of the personnel working at close range at the second transmission power. While performing identity authentication, the portable terminal is used as a relay node to forward alarm data.

[0010] Among them, when the adaptive wireless communication module transmits periodic heartbeat data at the first transmission power, it adopts an adaptive frequency hopping mechanism based on the characteristics of electromagnetic interference inside the cabinet; the main control processing module reuses the busbar power frequency harmonics and mechanical vibration data collected by the vibration sensor and the energy harvesting unit to construct a low-noise spectrum mask in real time, and dynamically avoids radio frequency interference frequency points generated by corona or partial discharge inside the high-voltage cabinet, and selects the idle frequency point with the highest signal-to-noise ratio as the heartbeat data transmission channel.

[0011] The energy harvesting unit includes an open-type current transformer energy harvesting coil, which also serves as a secondary sensing element for load fluctuations on the busbar of the power distribution cabinet. The power management circuit is equipped with a nonlinear wide-range adaptive impedance matching circuit. When the busbar current is in a low-load state below the preset current threshold, resulting in insufficient induced power, the quality factor of the matching circuit is improved and the supercapacitor energy storage unit is linked to provide peak power supply. When the busbar current suddenly surges and exceeds the preset overcurrent threshold, the leakage protection is activated.

[0012] The power management circuit controls the supercapacitor energy storage unit to provide uninterrupted power supply using a predictive seamless switching logic: the main control processing module monitors the falling edge slope and phase characteristics of the AC waveform at the voltage detection interface in real time. When a power outage trend caused by relay protection action or system fault is detected, the supercapacitor energy storage unit is controlled to switch to the main power supply circuit in advance within the time margin before the bus voltage drops. During the switching transition period, the current execution state of the audible and visual alarm module is forcibly latched to prevent alarm interruption caused by system reset at the moment of power outage.

[0013] The integrated audible and visual alarm power distribution cabinet door status monitoring device is integrated into a flame-retardant and explosion-proof enclosure. The top surface of the enclosure adopts a shielding grid structure. The metal conductor of the shielding grid is conformally interconnected with the ground plane of the internal PCB motherboard to form a composite coplanar waveguide antenna structure to optimize the radiation directionality of the adaptive wireless communication module. Vibration sensors and Hall effect sensors are arranged on the PCB motherboard at the electromagnetic wave transmission blind zone corresponding to the shielding grid. The shielding grid also serves as a physical isolation layer to resist high-voltage arc impact and a structural reinforcing rib to resist mechanical deformation.

[0014] This application provides a power distribution cabinet door status monitoring device integrating audible and visual alarms. This solution uses a multi-modal sensing module to simultaneously collect door displacement, mechanical impact signals, and the cabinet's energized status. This multi-dimensional data is then input into the main control processing module for spatiotemporal alignment and logical association, accurately determining whether the door opening behavior constitutes illegal prying, accidental activation, or normal maintenance. Based on this determination, the audible and visual alarm module implements a tiered warning strategy. When illegal prying and energization are detected, a high-frequency flashing light and a rapid buzzer are triggered. In case of accidental activation, only a continuous light and a single-tone warning are triggered, ensuring that the alarm method matches the actual risk level and effectively avoiding false alarms caused by a single signal source. Furthermore, the adaptive wireless communication module dynamically adjusts the radio frequency transmission power according to the door's opening and closing status. When the door is open, the power is automatically reduced to below a safe threshold, thereby reducing electromagnetic radiation exposure for personnel working nearby. Simultaneously, high-power transmission is restored when the door is closed to ensure data link stability. Furthermore, the power supply module utilizes the energy harvesting unit to draw power from the busbar and immediately controls the supercapacitor energy storage unit to intervene when a power failure is detected in the cabinet, achieving uninterrupted power supply under all operating conditions. This effectively solves the problems of traditional monitoring devices being unable to distinguish the nature of operations, having a high false alarm rate, and failing upon power failure. It significantly improves the accuracy, environmental adaptability, and operational reliability of the substation security system, providing solid technical support for the intelligent operation and maintenance of power facilities.

[0015] In summary, this application constructs a logically rigorous and fully functional closed-loop cabinet door status monitoring system through the systematic collaboration of multi-source data fusion, hierarchical response mechanism, dynamic power regulation, and self-sustaining power supply system. This system not only achieves accurate identification and differentiated handling of various opening behaviors, but also ensures continuous online capability in complex electromagnetic environments and sudden power outage scenarios, thus possessing extremely high engineering application value. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 A structural block diagram of a transformer substation door status monitoring device integrating audible and visual alarms provided in this application; Figure 2 This is a structural block diagram of the audible and visual alarm module provided in this application; Figure 3 This is a structural diagram of the flame-retardant and explosion-proof enclosure provided in this application.

[0018] In the diagram: 1-Multimodal sensing module; 2-Main control processing module; 3-Audio-visual alarm module; 4-Adaptive wireless communication module; 5-Sustaining power supply module; 6-High-brightness multi-color LED array; 7-Piezoelectric high-frequency buzzer; 8-Audio-visual driving circuit; 9-Flame-retardant and explosion-proof housing; 10-Shielding grid structure; 11-PCB motherboard. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0020] First embodiment: In the operation and maintenance of power distribution systems, real-time monitoring of cabinet door status is crucial for ensuring the safety of power equipment, preventing unauthorized intrusion, and standardizing maintenance procedures. Existing power distribution cabinet door status monitoring technologies largely rely on single mechanical switches or simple magnetic induction devices, which can only determine the open or closed state of the cabinet door but cannot effectively distinguish the specific reasons for its opening, such as unauthorized prying, accidental touch by maintenance personnel, or normal authorized maintenance operations. This single-dimensional monitoring method is prone to high false alarm rates and lacks an effective hierarchical response mechanism in complex field environments. Furthermore, traditional monitoring devices often rely on external power supply; once a power failure occurs in the power distribution cabinet, the monitoring device immediately fails, unable to provide alarm information in critical accident situations. Simultaneously, existing technologies fail to consider the potential electromagnetic radiation impact on personnel working at close range when the cabinet door is open for maintenance, posing a safety hazard.

[0021] To address the aforementioned issues, this application provides a power distribution cabinet door status monitoring device integrating audible and visual alarms. The device aims to achieve accurate identification and graded response to the cabinet door status through multi-dimensional data fusion analysis and intelligent decision-making, and to maintain stable system operation and personnel safety under conditions of no external power supply and special operating conditions.

[0022] Based on the above issues, please refer to Figures 1-3 This application provides a transformer substation door status monitoring device with integrated audible and visual alarm, the device comprising: The multimodal sensing module 1 is configured to collect multidimensional status data of the power distribution cabinet. The multimodal sensing module 1 includes a Hall effect magnetic sensor for detecting the displacement of the cabinet door, a vibration sensor for detecting the mechanical impact signal of the cabinet door, and a voltage detection interface for obtaining the energized state of the cabinet. The main control processing module 2 is connected to the multimodal sensing module 1, the audible and visual alarm module 3, the adaptive wireless communication module 4 and the power supply module 5 respectively. The main control processing module 2 is configured to perform spatiotemporal alignment and logical association of the displacement, mechanical impact signal and electrical status in the multidimensional status data in order to determine whether the cabinet door opening behavior belongs to the illegal prying state, the abnormal accidental touch state or the normal maintenance state. The audible and visual alarm module 3 is configured to execute a graded warning strategy based on the status judgment result output by the main control processing module 2. The graded warning strategy includes: when it is determined to be an illegal prying state and the cabinet is energized, a high-frequency flashing light and a rapid buzzer are triggered; when it is determined to be an abnormal accidental touch state, a constant light and a single tone are triggered. The adaptive wireless communication module 4 is configured to dynamically adjust the radio frequency transmission power according to the cabinet door status output by the main control processing module 2. Specifically, when the cabinet door is detected to be in a closed state, periodic heartbeat data is transmitted at a first transmission power; when the cabinet door is detected to be in an open state, the transmission power is reduced to a second transmission power lower than a preset safety threshold to reduce electromagnetic radiation exposure to personnel working at close range, and the transmission power is restored to the first transmission power after the cabinet door is closed again. The power supply module 5 includes an energy harvesting unit, a supercapacitor energy storage unit, and a power management circuit. The energy harvesting unit is configured to draw power from the busbar inside the cabinet or collect auxiliary power. The power management circuit is configured to control the supercapacitor energy storage unit to provide uninterrupted power to the device when the voltage detection interface detects that the cabinet has lost power.

[0023] The core innovation of this application lies in constructing an intelligent cabinet door status discrimination system based on multimodal data fusion and logical association, and linking it with hierarchical alarms, adaptive communication, and self-sustaining power supply mechanisms to form a closed-loop intelligent monitoring solution. By aligning the data from the Hall effect magnetic sensor, vibration sensor, and voltage detection interface in time and space, this application can effectively distinguish three distinct behavior modes: illegal prying, abnormal accidental contact, and normal maintenance, overcoming the shortcomings of existing technologies that are prone to false alarms based on a single displacement signal.

[0024] The multimodal sensing module 1 collects real-time data on the displacement, vibration, and electrical status of the cabinet door and transmits it to the main control processing module 2. The main control processing module 2 performs synchronous analysis and logical matching on the data. If it detects severe vibration accompanied by displacement and the cabinet is energized, it is determined to be an illegal prying and instructs the audible and visual alarm module 3 to trigger a high-frequency flash and a rapid buzzer. At the same time, it controls the adaptive wireless communication module 4 to optimize the power strategy while maintaining necessary communication. If it detects displacement but no significant vibration, it is determined to be an abnormal false trigger or normal maintenance and triggers the corresponding mild warning. Throughout this process, the power supply module 5 continuously monitors the bus voltage. Once the main power supply fails, the supercapacitor energy storage unit immediately takes over the power supply to ensure that the system can still complete the status judgment and alarm output under extreme conditions.

[0025] As a preferred embodiment, the solution of this application is specifically implemented as follows: In a substation scenario, when maintenance personnel open a cabinet door for routine maintenance with a valid work order, the Hall effect sensor detects door displacement, but the vibration sensor does not detect a mechanical impact signal exceeding the threshold. The main control processing module 2, combined with a preset time period or an authorized signal issued from the background, determines it to be a normal maintenance state. The audible and visual alarm module 3 only triggers a low-frequency breathing light indicator, and the adaptive wireless communication module 4 reduces its transmission power to the second transmission power to reduce radiation to personnel. At the same time, the power supply module 5 monitors that the bus voltage is normal and is powered by the energy harvesting unit. If unauthorized personnel attempt to forcibly pry open the cabinet door, the vibration sensor instantly detects a high-frequency, high-amplitude mechanical impact signal, and the Hall effect sensor detects displacement. The main control processing module 2 immediately determines it to be an illegal prying state, and the audible and visual alarm module 3 immediately emits a high-frequency flash and a rapid buzzer to deter on-site. The adaptive wireless communication module 4 sends alarm data to the monitoring center at the first transmission power or a specific emergency mode. Even if a power grid failure causes the bus to lose power, the power management circuit will control the supercapacitor energy storage unit to seamlessly switch power supply within milliseconds to ensure that the alarm signal is not interrupted.

[0026] Through the above technical solutions, this application achieves the following beneficial effects: Because the multimodal sensing module 1 jointly collects and spatiotemporally aligns the displacement, vibration, and electrical states, it can accurately distinguish between illegal prying, abnormal accidental contact, and normal maintenance, significantly reducing the false alarm rate and improving the intelligence level of the security system; Because the audible and visual alarm module 3 can execute a graded warning strategy based on the judgment results, it can provide targeted on-site responses to different types of cabinet door opening behaviors, enhancing the deterrent effect against illegal intrusion while avoiding excessive interference with normal maintenance operations; Because the adaptive wireless communication module 4 can dynamically reduce the radio frequency transmission power when the cabinet door is opened, it effectively reduces the electromagnetic radiation exposure of personnel working at close range, improving the safety of the working environment; Because the power supply module 5 combines inductive energy harvesting and supercapacitor energy storage technologies and achieves uninterrupted power supply switching when a power failure is detected, it ensures that the device can continue to operate online under extreme conditions such as grid failures or power outages, avoiding the generation of monitoring blind spots.

[0027] Furthermore, the Hall effect magnetic sensor includes a Hall element fixed to the side of the cabinet door and a permanent magnet fixed to the cabinet door frame; the vibration sensor is a piezoelectric vibration sensor or a microelectromechanical system accelerometer, which is attached to the surface of the metal plate inside the cabinet door; the voltage detection interface is electrically connected to the busbar or live display device in the power distribution cabinet through a high-voltage step-down isolation circuit.

[0028] When the transformer cabinet door moves, the Hall element fixed to the side of the door moves with the door, changing its position relative to the permanent magnet fixed to the door frame. This causes a change in the electrical signal output by the Hall element, thus reflecting the displacement of the cabinet door in real time. Simultaneously, if the cabinet door is subjected to an external impact, a vibration sensor attached to the surface of the metal plate inside the door immediately detects the vibration wave and converts it into an electrical signal output. Furthermore, a high-voltage step-down isolation circuit collects the voltage signal from the busbar or the live display device in real time, and after step-down isolation processing, outputs a low-voltage signal representing the energized state of the cabinet. These three signals represent the displacement, force, and energized state of the cabinet door, respectively. Through this specific sensor selection and installation layout, accurate perception of the cabinet door's state from different physical dimensions is achieved.

[0029] Through the above technical solutions, this application achieves the following: by adopting a separate Hall element and permanent magnet structure, the wear problem caused by mechanical contact is avoided, thus improving the long-term stability and anti-interference ability of displacement detection; by directly attaching the vibration sensor to the surface of the metal plate, the coupling efficiency of mechanical vibration is enhanced, improving the acquisition accuracy of small impact signals and facilitating the accurate extraction of impact features; by introducing a high-voltage step-down isolation circuit, effective isolation between strong and weak currents is achieved, ensuring electrical safety during voltage detection and preventing damage to the monitoring device from high-voltage faults.

[0030] Furthermore, the specific logic for the main control processing module 2 to determine the cabinet door opening behavior is as follows: if the vibration sensor detects a mechanical impact signal exceeding the first set threshold within a preset first time window, and the Hall effect sensor detects the cabinet door displacement, it is determined to be an illegal prying state; if the Hall effect sensor detects the cabinet door displacement, but the vibration sensor does not detect a mechanical impact signal or the mechanical impact signal is lower than the second set threshold, and no legitimate identity authentication signal is received, it is determined to be an abnormal accidental touch state; if neither of the above two situations applies, it is determined to be a normal maintenance state.

[0031] The first time window refers to the time interval during which the main control processing module 2 synchronously acquires and compares vibration and displacement signals. Its length can be set according to the response speed requirements and anti-interference needs of the actual application scenario; for example, it can be any value between 0.5 seconds and 2 seconds. This embodiment does not impose any special limitation on this. The function of this first time window in the overall technical solution is to ensure the strong temporal correlation between the two physical events, mechanical impact and cabinet door displacement, preventing misjudgment due to environmental noise or asynchronous independent events. By simultaneously satisfying both the impact exceeding the threshold and displacement within this window, the system can lock onto the composite action with destructive characteristics, thereby outputting the judgment result of an illegal prying state.

[0032] The first set threshold refers to the critical point of the signal amplitude or energy value output by the vibration sensor, used to distinguish between normal environmental vibration and destructive mechanical impact. The value of this threshold can be set according to the actual situation, based on the installation environment of the power distribution cabinet, the cabinet material, and the characteristics of surrounding mechanical interference sources. For example, it can be 3 to 5 times the average background vibration amplitude obtained from historical data statistics, or it can be based on the peak acceleration corresponding to the resonant frequency of the cabinet structure. This application does not impose any special limitations on this. The first set threshold is used in conjunction with a first time window. When the signal collected by the vibration sensor within the window period exceeds this threshold, it indicates that the cabinet door has been subjected to an external force sufficient to cause structural deformation or lock damage. If this is combined with the displacement detected by the Hall effect sensor, a complete chain of evidence for determining an illegal prying state can be formed.

[0033] The second set threshold refers to the lower limit of the vibration signal used to identify slight touch or abnormal probing behavior, and its value is usually lower than the first set threshold. This threshold can be a fixed value or an adaptive value that is dynamically adjusted according to the ambient background noise. For example, it can be 10% to 30% of the first set threshold, or slightly higher than the maximum ambient background noise. This application does not impose any special limitations on this. The role of the second set threshold in the logical judgment is to act as a filter for abnormal accidental touch states: when the Hall effect sensor detects that the cabinet door has been displaced (i.e., the door is opened), but the vibration sensor does not detect a significant impact (below the second set threshold or no signal is detected), it indicates that the opening behavior is not accompanied by violent destruction characteristics; if the system has not yet received a legitimate identity authentication signal at this time, it is inferred that the behavior may be an unauthorized person's probing opening or accidental touch, and thus it is determined to be an abnormal accidental touch state.

[0034] The legitimate authentication signal refers to the confirmation instruction sent by authorized maintenance personnel to the main control processing module 2 via a portable terminal, card reader, or biometric device, used to prove that the current cabinet door opening behavior is a planned maintenance operation. The source form of this signal can be set according to the actual situation, such as a digital signature after a successful Bluetooth encrypted handshake, an electrical signal after a successful RFID tag reading, or a correct password sequence input through a wired interface. This application embodiment does not make any special limitations on this. The legitimate authentication signal and the vibration absence condition together constitute the logical branch for determining the abnormal false touch state, and also serve as the key basis for excluding illegal prying and abnormal false touch, and finally classifying it as a normal maintenance state; that is, when cabinet door displacement is detected and a legitimate authentication signal is received, regardless of the vibration signal (as long as it does not reach the extreme damage level of illegal prying), the system tends to determine it as a normal maintenance state to avoid generating false alarms for compliant operations.

[0035] Specifically, the working process and principle of this application are as follows: The main control processing module 2 monitors the data streams from the vibration sensor and the Hall effect sensor in real time. When the system captures the displacement jump signal output by the Hall effect sensor, it immediately backtracks and retrieves the vibration data within a preset first time window. If the retrieval result shows that there is a mechanical impact signal exceeding the first set threshold within the window, the logic circuit directly triggers the flag of the illegal prying state, indicating that the cabinet door is being violently damaged; if the retrieval result shows that the vibration signal is missing or the amplitude is lower than the second set threshold, the logic circuit further queries the status of the identity authentication module. If no legitimate identity authentication signal is received, the flag of the abnormal accidental touch state is triggered, indicating that there is an unauthorized opening attempt; if a legitimate identity authentication signal is received at the same time as the above displacement occurs, or if the combination of vibration and displacement does not meet the characteristics of the first two situations, the system marks the current behavior as a normal maintenance state. The entire judgment process achieves a refined classification of the nature of cabinet door opening through the spatiotemporal alignment and logical interlocking of multi-dimensional data.

[0036] Through the above technical solution, this application realizes the use of a dual-condition linkage mechanism of impact and displacement, which effectively filters out false alarms caused by the susceptibility of a single sensor to environmental interference. This is because illegal prying is only determined when both high-intensity impact and displacement are met simultaneously within a specific time window, thereby significantly reducing the sensitivity to non-destructive vibrations. By introducing a legitimate identity authentication signal as the third dimension of logical judgment, the technical problem of distinguishing between authorized operation and illegal intrusion when only displacement signal is available is solved. This is because the system verifies the identity signal when it detects displacement without significant vibration, and only determines it as an abnormal false touch when there is no authorized signal, thereby accurately identifying unauthorized exploratory opening behavior and reducing interference with normal maintenance work.

[0037] The audible and visual alarm module 3 includes a high-brightness multi-color LED array 6, a piezoelectric high-frequency buzzer 7, and an audible and visual driving circuit 8. When the main control processing module 2 outputs a normal maintenance status, the audible and visual alarm module 3 executes a silent strategy or triggers a low-frequency breathing light indicator to indicate that it is currently in authorized maintenance mode.

[0038] The sound and light driving circuit 8 refers to the power amplification and logic conversion interface circuit located between the main control processing module 2 and the sound and light alarm actuator. Its specific implementation can be set according to the actual situation. For example, it can be a discrete circuit containing a transistor switch array, or it can be a dedicated driver chip integrating PWM modulation function. This application embodiment does not make any special limitation on this. The functional positioning of the sound and light driving circuit 8 is as a signal relay and energy matching hub. It converts the low-level logic signal output by the main control processing module 2 into a high-level driving signal that can drive the high-brightness multi-color LED array 6 and the piezoelectric high-frequency buzzer 7, and adjusts the output waveform according to different state commands, thereby realizing different sound and light combination modes in the graded warning strategy.

[0039] Specifically, when the main control processing module 2 determines, based on the spatiotemporal alignment and logical association of multi-dimensional state data, that the current cabinet door opening behavior is neither an illegal prying state nor an abnormal accidental touch state, i.e., it is determined to be a normal maintenance state, the audible and visual alarm module 3 enters the authorized maintenance mode response process. In this process, the audible and visual drive circuit 8 receives the normal maintenance identification signal from the main control processing module 2, and then cuts off the power supply or drive signal to the piezoelectric high-frequency buzzer 7, keeping it silent to avoid continuous noise interference during legitimate maintenance work, ensuring a quiet and efficient working environment. At the same time, the audible and visual drive circuit 8 controls the high-brightness multi-color LED array 6 to work in a specific low-frequency mode, such as presenting a slow change in green brightness (breathing light effect). This visual indication is distinct from the flashing or constant light in an emergency, and can clearly indicate to surrounding personnel that the current operation is a legitimate behavior certified by the system, preventing panic or secondary alarms caused by misjudgment.

[0040] The adaptive wireless communication module 4 includes a long-range wide area network module and a short-range low-power Bluetooth module. When the cabinet door is detected to be open, the main control processing module 2 shuts down the radio frequency front-end of the long-range wide area network module and activates the short-range low-power Bluetooth module to establish an encrypted local communication link with the portable terminal of the personnel working at close range at the second transmission power. While performing identity authentication, the portable terminal is used as a relay node to forward alarm data.

[0041] Long-range wide-area network (WAN) modules refer to wireless communication units that support long-distance, wide-coverage communication protocols. These can be communication modules based on technologies such as NB-IoT, LoRa, LTE-Cat1, or 5G RedCap. They are primarily used to periodically upload status data collected by monitoring devices to a remote monitoring center when the cabinet door is closed or during normal operation and maintenance. While these WAN modules typically have high transmission power and long transmission distances, their continuous high-frequency radio frequency radiation may pose a potential health risk when the cabinet door is open and personnel are in close proximity to the cabinet. Therefore, their use needs to be restricted in specific scenarios.

[0042] A short-range low-power Bluetooth module refers to a short-range wireless communication unit built on Bluetooth Low Energy technology. It typically operates in the 2.4GHz ISM band and features low power consumption, fast connection establishment, and high security. This short-range low-power Bluetooth module can establish a point-to-point encrypted communication link with portable terminals carried by operators (such as smartphones, dedicated handheld inspection devices, or tablets). In this application, the short-range low-power Bluetooth module not only performs data transmission but also serves as an authentication interface, verifying the operator's legitimate authority through a two-way handshake with the portable terminal.

[0043] The second transmission power refers to a lower power level set to meet electromagnetic compatibility requirements and human radiation safety standards, and its value is strictly lower than the preset safety threshold. The specific value of this second transmission power can be set according to the communication distance requirements, environmental interference levels, and relevant regulatory limits in the actual application scenario. For example, it can be -10dBm, 0dBm, or +4dBm, etc., and this application embodiment does not impose any special limitations on this. By adopting this second transmission power, the near-field low-power Bluetooth module can minimize electromagnetic radiation exposure to personnel working at close range while ensuring stable communication with portable terminals.

[0044] A portable terminal can refer to a mobile electronic device with wireless communication capabilities, data processing capabilities, and a human-machine interface, running an application or middleware compatible with the monitoring device of this application. After the local communication link is established, the portable terminal first performs an identity authentication process to verify whether the current operator has maintenance or operation permissions. After successful authentication, the portable terminal further acts as a relay node, receiving alarm data or status information generated by the monitoring device, and using its stronger communication capabilities (such as 4G / 5G / Wi-Fi) to forward the data to the cloud server or back-end management system, thereby achieving secure data backhaul and path optimization.

[0045] An encrypted local communication link can refer to a data channel that uses symmetric or asymmetric encryption algorithms to protect transmitted data, such as AES-128, AES-256, or elliptic curve cryptography (ECC). This encryption mechanism ensures that during the high-risk window period when the cabinet door is open, the command interaction and data transmission between the monitoring device and the external terminal are not eavesdropped on, tampered with, or forged, thereby guaranteeing the overall security of the system.

[0046] When the main control processing module 2 detects the cabinet door displacement through the multimodal sensing module 1 and determines that the cabinet door is open, the system immediately triggers the communication mode switching logic. First, the main control processing module 2 sends a shutdown command to the long-range wide area network module, cutting off the power supply to its radio frequency front-end or putting it into a deep sleep state, thereby eliminating the high-intensity radio frequency radiation source from the physical source. Subsequently, the main control processing module 2 activates the short-range low-power Bluetooth module, which broadcasts a specific service UUID (Universally Unique Identifier) ​​at the second transmit power. After scanning the broadcast signal, a nearby portable terminal initiates a connection request, and both parties complete key exchange and identity authentication. After successful authentication, the monitoring device packages and sends the current cabinet door status, alarm level, and raw sensor data to the portable terminal, which then relays the data upload through its wide area network interface. When the cabinet door closes again and the system determines that it has returned to normal, the main control processing module 2 automatically shuts down the short-range low-power Bluetooth module and re-wakes up the long-range wide area network module, restoring the periodic heartbeat data transmission mode at the first transmit power.

[0047] Through the above technical solution, this application achieves a significant reduction in the electromagnetic radiation exposure level of operators in high-risk operation scenarios where cabinet doors are opened by shutting down the long-distance high-radiation communication module and switching to low-power Bluetooth communication mode. At the same time, by using a portable terminal as a trusted relay node, identity authentication and data encryption forwarding are completed locally. This not only solves the problem of not being able to perform on-site real-time identity verification in the traditional mode, but also utilizes the network resources of the on-site terminal to achieve reliable feedback of alarm data, thereby enhancing the safety and availability of the system in complex electromagnetic environments.

[0048] When the adaptive wireless communication module 4 transmits periodic heartbeat data at the first transmission power, it adopts an adaptive frequency hopping mechanism based on the characteristics of electromagnetic interference inside the cabinet. The main control processing module 2 reuses the busbar power frequency harmonics and mechanical vibration data collected by the vibration sensor and the energy harvesting unit to build a low-noise spectrum mask in real time, and dynamically avoids radio frequency interference frequency points generated by corona or partial discharge inside the high-voltage cabinet, and selects the idle frequency point with the highest signal-to-noise ratio as the heartbeat data transmission channel.

[0049] The adaptive frequency hopping mechanism based on the characteristics of electromagnetic interference within the cabinet refers to a technical means of dynamically adjusting the wireless communication frequency according to real-time changes in the electromagnetic environment inside the power distribution cabinet. The function of this mechanism is to solve broadband or narrowband radio frequency interference caused by corona discharge, partial discharge, and other phenomena under high-voltage environments, preventing interruption or errors in heartbeat data transmission. In the system linkage, this mechanism works closely with the main control processing module 2 and the adaptive wireless communication module 4: the main control processing module 2 acts as the decision center, receiving interference characteristic data from the sensor end, calculating and generating frequency hopping commands; the adaptive wireless communication module 4 acts as the execution unit, quickly switching to an interference-free or low-interference channel according to the commands. The result is that the communication link can automatically avoid noisy frequency points and always maintain operation on idle frequency points with a high signal-to-noise ratio, thereby ensuring the continuity and integrity of periodic heartbeat data.

[0050] The reuse of busbar power frequency harmonics and mechanical vibration data collected by vibration sensors and energy harvesting units refers to indirectly obtaining auxiliary information characterizing the intensity of electromagnetic interference using existing sensing resources in the device. Vibration sensors are typically piezoelectric or microelectromechanical system (MEMS) accelerometers, which not only detect mechanical shocks but also sensitively respond to cabinet micro-vibrations caused by high-voltage electric fields or electromagnetic force-induced vibrations. During the induction power harvesting process, the output waveform of the energy harvesting coil in the energy harvesting unit is superimposed with the power frequency harmonics of the busbar current and high-frequency noise components caused by partial discharge. These data are functionally redefined as fingerprint characteristics of the electromagnetic environment. In the linkage mechanism, this multi-source heterogeneous data is transmitted to the main control processing module 2 as input variables for constructing the interference model, avoiding the need for additional deployment of dedicated spectrum analyzers or RF detection antennas and maximizing the utilization of hardware resources.

[0051] Real-time construction of the noise floor spectrum mask refers to the dynamic model generated by the main control processing module 2 after performing time-frequency analysis on the acquired multimodal data, representing the noise energy distribution of each frequency band at the current moment. This mask is essentially a threshold curve or probability distribution map that updates over time, used to identify which frequency bands are occupied by strong interference. Specifically, the main control processing module 2 performs a Fast Fourier Transform (FFT) on the voltage waveform output by the energy harvesting unit to extract the amplitude characteristics of specific harmonic components. Simultaneously, combined with the spectral characteristics of the vibration signal, a preset mapping algorithm is used to calculate the radio frequency noise intensity of the corresponding frequency band. This feature serves as the basis for frequency hopping decisions in the overall scheme, transforming continuous physical quantities into discrete frequency availability judgment logic.

[0052] Dynamic avoidance of radio frequency interference frequencies generated by corona or partial discharge within the high-voltage cabinet can refer to the communication system actively abandoning frequency channels whose noise power exceeds a preset safety threshold based on real-time feedback from the noise floor spectrum mask. Corona and partial discharge are common interference sources in high-voltage environments of power distribution cabinets, and the resulting radio frequency noise is random and impulsive. The specific implementation of this process can be as follows: when the main control processing module 2 detects that the noise energy of a certain frequency point is higher than the background noise baseline for several consecutive cycles, it marks that frequency point as disabled or high-priority avoidance and immediately notifies the adaptive wireless communication module 4 to stop transmitting data at that frequency point. This action forms a closed-loop control with the heartbeat data transmission process, ensuring that the data stream does not pass through contaminated spectrum regions.

[0053] Selecting the idle frequency with the highest current signal-to-noise ratio (SNR) as the heartbeat data transmission channel means, after eliminating all interfering frequencies, choosing the frequency with the best signal quality from the remaining available spectrum resources for data transmission. Signal-to-noise ratio (SNR) is a key indicator of communication quality; the highest SNR signifies the strongest anti-interference capability and the lowest bit error rate. The implementation logic for this step can be as follows: the main control processing module 2 iterates through the list of frequencies not marked as interference, estimates the expected SNR of each frequency, and uses a comparison algorithm to lock the frequency index corresponding to the optimal value. Then, it sends a switching command to the adaptive wireless communication module 4. The final operating state is that, under complex electromagnetic backgrounds, the device can automatically find and reside on the cleanest communication channel, similar to navigation and obstacle avoidance, to complete the heartbeat packet transmission.

[0054] Specifically, the working process of this application is as follows: During the normal operation of the power distribution cabinet and when the cabinet door is closed, the adaptive wireless communication module 4 prepares to transmit periodic heartbeat data at the first transmission power. At this time, the main control processing module 2 synchronously starts the interference sensing program, continuously collecting the output signal of the vibration sensor and the induced voltage waveform of the energy harvesting unit. By performing spectrum analysis on these signals, the main control processing module 2 identifies the characteristic noise frequency band caused by bus corona or partial discharge, and updates the background noise spectrum mask in real time accordingly. Once the mask shows that the currently used communication frequency point falls into the strong interference area, the main control processing module 2 immediately calculates the new optimal frequency point and controls the adaptive wireless communication module 4 to perform frequency hopping operation, switching to the idle channel with the highest signal-to-noise ratio to continue transmitting heartbeat data. The entire process is completed in milliseconds, resulting in seamless maintenance of the communication link.

[0055] The energy harvesting unit includes an open-type current transformer energy harvesting coil, which also serves as a secondary sensing element for load fluctuations on the busbar of the power distribution cabinet. The power management circuit is equipped with a nonlinear wide-range adaptive impedance matching circuit. When the busbar current is in a low-load state below the preset current threshold, resulting in insufficient induced power, the quality factor of the matching circuit is improved and the supercapacitor energy storage unit is linked to provide peak power supply. When the busbar current suddenly surges and exceeds the preset overcurrent threshold, the leakage protection is activated.

[0056] An open-type current transformer energy harvesting coil refers to an induction coil with an openable magnetic core structure, configured to be sleeved outside the busbar of a substation, utilizing the alternating magnetic field generated by the busbar current to obtain electrical energy through electromagnetic induction. In this application, this open-type current transformer energy harvesting coil not only performs the function of energy harvesting but also serves as a secondary sensing element for load fluctuations on the substation busbar. That is, its output induced signal is used for both rectification and power supply, and also reflects the current current amplitude and fluctuation characteristics of the busbar, thus achieving integration of energy harvesting and monitoring. The specific turns ratio, magnetic core material (such as nanocrystalline alloy, ferrite, etc.), and open mechanical structure of this open-type current transformer energy harvesting coil can be set according to actual conditions; this application does not impose any special limitations on these aspects. By reusing this coil as a sensing element, the installation requirements for additional sensors are reduced, the overall size and cost of the device are lowered, and the consistency between load monitoring data and energy harvesting status in time and space is ensured.

[0057] A nonlinear wide-range adaptive impedance matching circuit is an electronic circuit network that dynamically adjusts its input impedance characteristics according to changes in the input source impedance. It is installed within the power management circuit to optimize energy transfer efficiency between the energy harvesting unit and the downstream load. The function of this nonlinear wide-range adaptive impedance matching circuit is to solve the problem of unstable energy harvesting caused by large fluctuations in busbar current: when the busbar current is small, resulting in a low induced electromotive force, the circuit improves the quality factor (Q value) of the circuit by adjusting the parameters of the internal variable inductor or capacitor, thereby obtaining a higher voltage gain near the resonant point and ensuring effective energy extraction even with weak energy input; when the busbar current is too large, the circuit limits the transmitted power by changing the impedance matching state to prevent overload of the downstream circuit. The specific topology of this nonlinear wide-range adaptive impedance matching circuit can be a passive matching circuit based on an LC resonant network or an active impedance transformation circuit controlled by active switching devices; this application does not impose any special limitations on this. This circuit has a close working relationship with the supercapacitor energy storage unit and the main control processing module 2, together forming a dynamic energy management system.

[0058] A supercapacitor energy storage unit is an electrochemical energy storage device with high power density and fast charge / discharge characteristics. In this scheme, it serves as a buffer to smooth out instantaneous fluctuations in the output power of the energy harvesting unit. When the busbar is under low load, the energy induced by the open-type current transformer's harvesting coil may be insufficient to support the real-time operating power consumption of the entire device. At this time, the nonlinear wide-range adaptive impedance matching circuit improves the quality factor, while the supercapacitor energy storage unit releases pre-stored charge to provide peak power supply, filling the energy gap and ensuring uninterrupted operation of the device. The capacity, rated voltage, and packaging form of the supercapacitor energy storage unit can be set according to the actual load power consumption and the expected duration of low load. For example, it can be a double-layer capacitor or a hybrid supercapacitor; this application does not impose any special limitations on these aspects.

[0059] The leakage protection mechanism refers to a protection strategy that automatically bypasses or dissipates excess energy when the input energy exceeds the system's withstand threshold. When the busbar current suddenly surges and exceeds the preset overcurrent threshold, the energy induced in the energy extraction coil of the open-type current transformer may rise sharply. If this energy is directly fed into the downstream circuit, it may damage the components. At this time, the power management circuit activates the leakage protection, which clamps the bus voltage within a safe range by connecting the bleeder resistor connected in parallel in the energy extraction circuit or by directing the excess energy to other non-critical loads. The preset overcurrent threshold can be set according to the rated current range of the substation and the withstand voltage and current limits of the downstream electronic components. This application does not impose any special limitations on this.

[0060] During operation, the open-type current transformer's energy extraction coil senses the busbar current in real time. On one hand, it rectifies the induced AC power and sends it to the power management circuit; on the other hand, it transmits signals reflecting load fluctuations to the main control processing module 2. The nonlinear wide-range adaptive impedance matching circuit within the power management circuit monitors the energy level at the input in real time. When the busbar current is detected to be lower than the preset current threshold, it indicates a low-load condition and insufficient induced energy. The circuit automatically adjusts parameters to improve the quality factor and enhance energy extraction efficiency, and simultaneously issues commands to control the supercapacitor energy storage unit to discharge, which is then added to the current energy extraction power to meet the device's power supply needs, achieving peak power supplementation. Conversely, when a sudden surge in busbar current is detected and exceeds the preset overcurrent threshold, the circuit immediately triggers the leakage protection logic, bypassing or dissipating excess energy to prevent high-voltage surges from damaging subsequent circuits. The entire process achieves stable energy extraction and safety protection across a wide range, from microampere-level small currents to kiloampere-level large currents.

[0061] The power management circuit controls the supercapacitor energy storage unit to provide uninterrupted power supply using a predictive seamless switching logic: the main control processing module 2 monitors the falling edge slope and phase characteristics of the AC waveform at the voltage detection interface in real time. When it detects a power outage trend caused by relay protection action or system fault, it controls the supercapacitor energy storage unit to switch to the main power supply circuit in advance within the time margin before the bus voltage drops. During the switching transition period, it forcibly latches the current execution state of the audible and visual alarm module 3 to prevent system reset caused by power outage from interrupting the alarm.

[0062] Predictive seamless switching refers to a forward-looking power control strategy based on voltage waveform trend analysis. Its function is to eliminate power supply interruptions caused by detection lag in traditional passive switching mechanisms. This technology is closely integrated with the main control processing module 2, the voltage detection interface, and the supercapacitor energy storage unit: the main control processing module 2 continuously collects real-time analog bus voltage data through the voltage detection interface, performs differential calculations to obtain the falling edge slope, and combines this with phase characteristics for comprehensive analysis. Once the judgment result meets the preset power outage trend conditions, the main control processing module 2 issues a pre-switching command to the power management circuit, driving the supercapacitor energy storage unit to complete the connection within the time margin before the bus voltage drops below the logic circuit's operating threshold. Through this integration, the system can establish a backup power supply path before a physical power outage occurs, resulting in a smooth transition of the power supply circuit and avoiding transient drops in load-side voltage below the reset threshold.

[0063] The main control processing module 2 refers to the core computing and control unit in the device. Its name in this scheme stems from its role in precisely controlling the spatiotemporal alignment of multi-dimensional state data, logical judgment, and power switching timing. This technical feature works in conjunction with the voltage detection interface and power management circuit: the main control processing module 2 internally runs a waveform analysis algorithm specifically designed to identify specific slope change rates and phase offsets in AC waveforms that characterize relay protection activation precursors or system faults. When these characteristic parameters exceed set thresholds, the main control processing module 2 immediately triggers the switching logic and sends a status latch signal to the audible and visual alarm module 3 during the transition time of the switch. This coordinated relationship ensures that the control logic and actuators maintain continuous operation even during moments of severe fluctuations or interruptions at the power source, resulting in alarm actions not being reset or interrupted due to transient disturbances in the power supply system.

[0064] Forced latching refers to the operation method of freezing and maintaining the output drive signal or internal register state of the audible and visual alarm module 3 during the critical period of power switching. This technical feature serves the stable coordination between the audible and visual alarm module 3 and the main control processing module 2: when the main control processing module 2 detects an impending power outage and initiates the supercapacitor switching procedure, it synchronously activates the latching mechanism, fixing the current sound frequency, flashing mode, or drive level of the audible and visual alarm module 3 at the state before the switchover, temporarily blocking update instructions or reset signals from other logic units. This coordination path aims to resist false resets caused by minor voltage ripples or ground potential fluctuations that may occur during the main / backup power switching process. The result of this coordination is that the audible and visual warning signal maintains continuous output throughout the entire power outage process, without flickering interruptions or silence gaps.

[0065] Specifically, the working process and principle of this application are as follows: During normal operation, the main control processing module 2 samples the AC waveform data of the bus voltage in real time through the voltage detection interface and continuously calculates the falling edge slope and phase angle changes of the waveform. When a relay protection action or a serious fault occurs on the grid side, causing the voltage to drop, the waveform will show a specific rapid downward trend and phase distortion characteristics. After the main control processing module 2 identifies this characteristic, it determines that an effective power outage will occur within the next few milliseconds to tens of milliseconds. Subsequently, before the bus voltage drops to the minimum threshold for maintaining system operation, the main control processing module 2 issues a control signal in advance, instructing the power management circuit to seamlessly integrate the supercapacitor energy storage unit into the main power supply circuit. At the same time, the main control processing module 2 sends a latching command to the audible and visual alarm module 3, forcing it to maintain the current alarm output state. After the supercapacitor is stably powered and the system confirms the switchover is completed, the latch is released, and the system resumes normal dynamic response logic.

[0066] The audible and visual alarm power distribution cabinet door status monitoring device is integrated into a flame-retardant and explosion-proof enclosure 9. The top surface of the enclosure adopts a shielding grid structure 10. The metal conductor of the shielding grid is conformally interconnected with the ground plane of the internal PCB motherboard 11 to form a composite coplanar waveguide antenna structure to optimize the radiation directionality of the adaptive wireless communication module 4. Vibration sensors and Hall effect sensors are arranged on the PCB motherboard 11 at the electromagnetic wave transmission blind zone corresponding to the shielding grid. The shielding grid also serves as a physical isolation layer to resist high-voltage electric arc impact and a structural reinforcing rib to resist mechanical deformation.

[0067] When the device is in operation, all functional modules built into the flame-retardant and explosion-proof housing 9 operate normally. The radio frequency signal generated by the adaptive wireless communication module 4 is excited by the composite coplanar waveguide antenna mode through conformal coupling between the PCB ground plane and the metal conductor of the shielding grille on the top surface of the housing. The signal is radiated outward through the grille structure. During this process, the vibration sensor and Hall effect sensor located at specific positions on the PCB motherboard 11 are minimized from radio frequency interference because they are within the electromagnetic transmission blind zone formed by the shielding grille, and can continuously and stably collect the vibration and displacement data of the cabinet door. At the same time, if an abnormality occurs inside the power distribution cabinet and causes a high-voltage arc, the shielding grille uses its dense metal mesh structure to block the arc from penetrating and its reinforcing rib structure to maintain the integrity of the housing and protect the internal circuitry from physical damage.

[0068] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A transformer substation door status monitoring device integrating audible and visual alarms, characterized in that, include: The multimodal sensing module is configured to collect multidimensional status data of the power distribution cabinet. The multimodal sensing module includes a Hall effect sensor for detecting the displacement of the cabinet door, a vibration sensor for detecting the mechanical impact signal of the cabinet door, and a voltage detection interface for obtaining the energized state of the cabinet. The main control processing module is connected to the multimodal sensing module, the audible and visual alarm module, the adaptive wireless communication module and the power supply module respectively. The main control processing module is configured to perform spatiotemporal alignment and logical association of the displacement, mechanical impact signal and electrical status in the multidimensional state data in order to determine whether the cabinet door opening behavior belongs to illegal prying state, abnormal accidental touch state or normal maintenance state. The audible and visual alarm module is configured to execute a graded warning strategy based on the status determination result output by the main control processing module. The graded warning strategy includes: when it is determined to be an illegal prying state and the cabinet is energized, triggering a high-frequency flashing light and a rapid buzzer; when it is determined to be an abnormal accidental touch state, triggering a continuous light and a single-tone prompt. The adaptive wireless communication module is configured to dynamically adjust the radio frequency transmission power according to the cabinet door status output by the main control processing module. Specifically, it includes: when the cabinet door is detected to be in a closed state, performing periodic heartbeat data transmission at a first transmission power; when the cabinet door is detected to be in an open state, reducing the transmission power to a second transmission power lower than a preset safety threshold to reduce electromagnetic radiation exposure to personnel working at close range, and restoring the transmission power to the first transmission power after the cabinet door is closed again. The power supply module includes an energy harvesting unit, a supercapacitor energy storage unit, and a power management circuit. The energy harvesting unit is configured to draw power from the busbar inside the cabinet or collect auxiliary power. The power management circuit is configured to control the supercapacitor energy storage unit to provide uninterrupted power to the device when the voltage detection interface detects that the cabinet has lost power.

2. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 1, characterized in that, The Hall effect magnetic sensor includes a Hall element fixed to the side of the cabinet door and a permanent magnet fixed to the cabinet door frame; the vibration sensor is a piezoelectric vibration sensor or a microelectromechanical system accelerometer, which is attached to the surface of the metal plate inside the cabinet door; the voltage detection interface is electrically connected to the busbar or live display device in the power distribution cabinet through a high-voltage step-down isolation circuit.

3. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 2, characterized in that, The specific logic for the main control processing module to determine cabinet door opening behavior is as follows: If the vibration sensor detects a mechanical impact signal exceeding a first set threshold within a preset first time window, and the Hall effect sensor detects the displacement of the cabinet door, it is determined to be an illegal prying state. If the Hall effect sensor detects the displacement of the cabinet door, but the vibration sensor does not detect a mechanical impact signal or the mechanical impact signal is lower than the second set threshold, and no legitimate identity authentication signal is received, then it is determined to be an abnormal accidental touch state. If it does not fall into either of the above two categories, it is determined to be in normal maintenance condition.

4. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 3, characterized in that, The audible and visual alarm module includes a high-brightness multi-color LED array, a piezoelectric high-frequency buzzer, and an audible and visual driving circuit. When the main control processing module outputs a normal maintenance status, the audible and visual alarm module executes a silent strategy or triggers a low-frequency breathing light indicator to indicate that it is currently in authorized maintenance mode.

5. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 4, characterized in that, The adaptive wireless communication module includes a long-range wide area network module and a short-range low-power Bluetooth module. When the cabinet door is detected to be open, the main control processing module shuts down the radio frequency front-end of the long-range wide area network module and activates the short-range low-power Bluetooth module to establish an encrypted local communication link with the portable terminal of the personnel working at close range at the second transmission power. While performing identity authentication, the portable terminal is used as a relay node to forward alarm data.

6. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 5, characterized in that, When the adaptive wireless communication module transmits periodic heartbeat data at the first transmission power, it adopts an adaptive frequency hopping mechanism based on the characteristics of electromagnetic interference inside the cabinet. The main control processing module reuses the busbar power frequency harmonics and mechanical vibration data collected by the vibration sensor and the energy harvesting unit to construct a low-noise spectrum mask in real time, and dynamically avoids radio frequency interference frequency points generated by corona or partial discharge inside the high-voltage cabinet, and selects the idle frequency point with the highest signal-to-noise ratio as the heartbeat data transmission channel.

7. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 6, characterized in that, The energy harvesting unit includes an open-type current transformer energy harvesting coil, which also serves as a secondary sensing element for load fluctuations on the busbar of the power distribution cabinet. The power management circuit is equipped with a nonlinear wide-range adaptive impedance matching circuit. When the busbar current is in a low-load state below a preset current threshold, resulting in insufficient induced power, the quality factor of the matching circuit is improved and the supercapacitor energy storage unit is linked to provide peak power supply. When the busbar current suddenly surges and exceeds the preset overcurrent threshold, the leakage protection is activated.

8. The integrated audible and visual alarm power distribution cabinet door status monitoring device as described in claim 7, characterized in that, The power management circuit controls the supercapacitor energy storage unit to provide uninterrupted power supply using a predictive seamless switching logic: the main control processing module monitors the falling edge slope and phase characteristics of the AC waveform at the voltage detection interface in real time. When a power outage trend caused by relay protection action or system fault is detected, the supercapacitor energy storage unit is controlled to switch to the main power supply circuit in advance within the time margin before the bus voltage drops. During the switching transition period, the current execution state of the audible and visual alarm module is forcibly latched to prevent alarm interruption caused by system reset at the moment of power outage.

9. A transformer substation door status monitoring device integrating audible and visual alarm as described in claim 8, characterized in that, The integrated audible and visual alarm power distribution cabinet door status monitoring device is integrated into a flame-retardant and explosion-proof enclosure. The top surface of the enclosure adopts a shielding grid structure. The metal conductor of the shielding grid is conformally interconnected with the ground plane of the internal PCB motherboard to form a composite coplanar waveguide antenna structure to optimize the radiation directivity of the adaptive wireless communication module. The vibration sensor and the Hall effect sensor are arranged on the PCB motherboard at the electromagnetic wave transmission blind zone corresponding to the shielding grid. The shielding grid also serves as a physical isolation layer to resist high-voltage electric arc impact and a structural reinforcing rib to resist mechanical deformation.

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