Low-voltage power supply self-throwing device and control method thereof

Abstract

This invention relates to a low-voltage power supply automatic transfer device and its control method, specifically including: a main incoming power supply; a backup incoming power supply; a main circuit breaker; a backup circuit breaker; a low-voltage busbar; electrical equipment; and further including: a damping switching module; an oscillation suppression control unit; a detection unit; a blocking logic unit; a main and backup interlocking unit; wherein after the software logic interlocking is completed, the other closing output command is permanently blocked, maintaining the interlocking state effective, and is released when the power grid power supply returns to normal or a manual reset command is issued; a main control unit; a communication unit; and an auxiliary power supply unit. The beneficial effects are: designing a brand-new integrated solution with high-precision detection, adaptive damping smooth switching, pre-blocking, post-interlocking, and network remote transmission, based on the damping switching module, and innovatively designing an adaptive adjustable damping structure.

Description

Technical Field

[0001] This invention belongs to the field of low-voltage power distribution uninterruptible power supply control technology, specifically relating to a low-voltage power supply automatic transfer device and its control method. Background Technology

[0002] Existing low-voltage dual-power transfer switches and automatic transfer devices generally suffer from several technical shortcomings: low detection accuracy, capable of only roughly monitoring voltage and current, lacking high-precision online detection capabilities for contact temperature, circuit contact resistance, coil current, etc., and unable to detect minor equipment degradation and transient grid anomalies; and simple switching methods, mostly mechanically disconnecting before closing, which can lead to power outages and circulating current impacts during closing. Currently, damped smooth switching modules and complete sets of devices have emerged in the industry. These products employ a short-time closing principle using bridging damping resistors and current-limiting reactants to achieve a seamless transition from closing to disconnecting, reducing switching impacts to a certain extent, and are suitable for applications requiring resistance to power fluctuations and uninterrupted loads.

[0003] The inventors discovered significant shortcomings in existing damping smooth switching devices during their research: they only have fixed-parameter damping modules, lack high-precision multi-dimensional detection capabilities, and cannot adaptively adjust damping parameters based on load size and harmonic content; they only have basic closing timing sequences and lack comprehensive pre-switching multi-interlocking logic, making it impossible to achieve all-round interlocking for asynchronous, overcurrent, sampling anomalies, and reverse power supply from electrical equipment; most only have simple mechanical interlocking and lack dedicated hardware and software dual interlocking units after switching, still presenting risks such as parallel operation of main and backup switches, excessive circulating current, and phase-to-phase short circuits; the damping module, detection unit, and control unit are independent and not integrated, resulting in slow linkage response and poor coordination; they lack complete network remote transmission capabilities, making it difficult to remotely transmit damping activation events, interlocking reasons, and interlocking statuses, hindering compatibility with unattended operation and maintenance of smart distribution networks.

[0004] Therefore, there is an urgent need for a low-voltage power supply automatic transfer device and its control method that overcomes the shortcomings of existing technologies, features adaptive adjustable damping smooth switching, multi-condition safety interlocking before switching, dual hardware and software interlocking after switching, and encrypted remote transmission of signals across the entire network. Summary of the Invention

[0005] To overcome the problems in existing technologies, the inventors have adopted an integrated low-voltage automatic transfer switch device and control method with high-precision detection, adaptive damping smooth switching, switching interlocking, and post-switching interlocking. This comprehensively improves power supply safety and reliability through a five-layer architecture: accurate detection, adaptive damping smooth execution, pre-locking safety interlocking, post-locking interlocking, and remote operation and maintenance. It automatically performs equipment inspection and predictive maintenance based on real-time data acquisition; under normal operating conditions, it supports manual switching modes / switching operations. The technical solution adopted in this invention is: a low-voltage automatic transfer switch device, comprising: Main incoming power supply; Backup power supply; The main circuit breaker is connected to the main incoming power supply; A backup circuit breaker is connected to the backup incoming power supply. Low-voltage busbar; The electrical equipment is connected to the main incoming power supply and the backup incoming power supply respectively through the low-voltage busbar via the main circuit breaker and the backup circuit breaker; Also includes: The damping switching module includes: an adjustable non-inductive damping resistor, an adjustable reactance, and a thyristor switching mechanism. The damping switching module is connected across the main circuit breaker and the standby circuit breaker. It collects load current, phase difference, and harmonic data in real time, and adjusts the damping resistance and reactance parameters according to the collected information. It adopts a short-time closing loop control sequence of closing before opening to actively suppress the closing loop transient circulating current. The oscillation suppression control unit detects circuit oscillations and outputs an adjustment amount that is inversely phase to the oscillation, thus canceling out the oscillation energy. The detection unit includes: a synchronous sampling chip, a PT / CT, a contact temperature sensor, and a micro resistance detection module. The detection unit collects the three-phase voltage, current, phase, frequency, and harmonics of the main incoming power supply, the backup incoming power supply, and the low-voltage bus, and determines the contact temperature, circuit contact resistance, and operating current of the opening and closing coils of the main circuit breaker and the backup circuit breaker. The interlocking logic unit determines the interlocking status of asynchronous interlocking, incoming line overcurrent fault interlocking, circuit breaker abnormal position interlocking, sampling circuit disconnection / distortion interlocking, reverse power flow interlocking, and local / remote manual maintenance interlocking. After triggering, the damping switching module is disabled. The primary and backup interlocking unit includes a dual redundancy architecture of hardware electrical interlocking and software logic interlocking. The hardware electrical interlock is cross-hard interlocked with the contacts of the main circuit breaker and the backup circuit breaker. After any circuit breaker is closed, the closing control circuit of the other circuit breaker is physically cut off. After the software logic interlock switch is completed, it permanently blocks the other closing output command, keeping the interlock state effective. It is released when the power grid power supply is restored to normal or a manual reset command is issued. The main control unit communicates with the main circuit breaker, the backup circuit breaker, the damping switching module, the oscillation suppression control unit, the detection unit, the interlocking logic unit, and the main / backup interlocking unit. The communication unit is connected to the main control unit via signals, outputs and displays control parameters, and provides control commands. The auxiliary power supply unit provides separate control power to the damping switching module, the oscillation suppression control unit, the interlocking logic unit, the main and backup interlocking unit, and the detection unit.

[0006] Furthermore, The detection unit has a voltage detection accuracy of ≤ ±0.05%, a current detection accuracy of ≤ ±0.1%, a temperature detection accuracy of ≤ ±0.2℃, and a contact resistance resolution of ≤ 0.5μΩ.

[0007] Furthermore, The damping switching module completes the switching without power outage and without circulating current in 15ms-25ms, and automatically trips and locks out after the timeout.

[0008] Furthermore, The detection unit includes a 24-bit ultra-high precision synchronous sampling chip.

[0009] Furthermore, The main control unit includes an industrial-grade dual-core processor with built-in data filtering, synchronous phase-locking, damping parameter adaptive adjustment, switching interlocking discrimination, post-switching interlocking control, fault analysis program, control detection, damping switching, interlocking, and interlocking timing.

[0010] Furthermore, The communication unit integrates Ethernet, wireless communication and industrial bus interfaces, and can remotely transmit real-time parameters, the damping switching module, smooth switching events, locking reasons, interlock status and fault recordings, and supports remote parameter setting and remote operation and maintenance.

[0011] A control method for a low-voltage power supply automatic transfer device includes the following steps: The low-voltage power supply automatic transfer device is initialized upon power-up, and completes hardware self-test, sampling channel calibration, damping module switching self-test, and interlocking logic and interlocking circuit self-test. The detection unit synchronously collects power grid electrical parameters, status parameters of the main circuit breaker and standby circuit breaker, and grid-connected operation parameters of the electrical equipment in real time. The main control unit performs filtering operations on the collected data, power quality analysis, and equipment health assessment, and simultaneously executes the pre-switching interlocking condition judgment; when the main control unit detects that the interlocking condition has been triggered, it immediately blocks the damping switching output, records the interlocking reason and sends it remotely, and returns to the loop monitoring. When there is no triggering lockout condition, the main incoming power supply is abnormal or the health deterioration of the main circuit breaker exceeds the threshold, the main control unit initiates the automatic transfer process, and the backup incoming power supply synchronizes the amplitude, frequency and phase of the main incoming power supply to close the backup circuit breaker. After the load has been completely transferred, disconnect the main circuit breaker and deactivate the damping switching module.

[0012] Furthermore, it also includes the following steps: After the switchover is completed, the main and backup interlocking unit is activated to forcibly lock the closing circuit of the main circuit breaker or the backup circuit breaker. The interlock status remains in effect until the power grid returns to normal or a manual reset is performed.

[0013] Furthermore, it also includes the following steps: The communication unit uploads detection data, switching records, interlocking events, and interlocking status throughout the process, enabling remote monitoring and traceability maintenance.

[0014] The advantages of this invention over existing technologies are as follows: 1) Based on the damping switching module, an innovative adaptive adjustable damping structure is designed, which differs from existing fixed parameter damping modules and can automatically match damping parameters according to load, harmonics, and phase difference; 2) With the help of the six-dimensional ultra-high precision synchronous detection of the detection unit, the electrical quantity and switch status are precisely monitored in all dimensions, providing accurate data support for smooth damping switching; 3) With the help of the interlocking logic unit, six safety interlocks are used before switching to avoid the safety risks of starting damping loop switching under conditions such as asynchrony, overcurrent, islanding, and sampling abnormality; 4) A main and backup interlocking unit is added, and after switching, the software and hardware are double interlocked to prevent the simultaneous closing of two switches after switching and to prevent long-term parallel operation and circulating current short circuit accidents after damping loop closing; 5) A brand-new integrated solution integrating high-precision detection, adaptive damping smooth switching, pre-interlocking, post-interlocking, and network remote transmission is designed; 6) The damping switching status, interlocking, and interlocking events are fully transmitted remotely, adapting to unattended operation and maintenance of intelligent distribution networks. Attached Figure Description

[0015] Figure 1 This is a topology diagram of a specific embodiment of the present invention; Figure 2 This is a flowchart of the control method according to a specific embodiment of the present invention; The annotation is represented as follows: 1-Main incoming power supply; 2-Backup incoming power supply; 3-Main circuit breaker; 4-Backup circuit breaker; 5-Low voltage busbar; 6-Damping switching module; 7-Suppressing oscillation control unit; 8-Interlocking logic unit; 9-Main and backup interlocking unit; 10-Detection unit; 11-Main control unit; 12-Communication unit; 13-Auxiliary power supply unit; 14-Electrical equipment. Detailed Implementation

[0016] The technical solutions in the embodiments are clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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, and therefore should not be construed as a limitation of the present invention.

[0017] To overcome the problems in existing technologies, the inventors have adopted an integrated low-voltage standby automatic transfer device and control method with high-precision detection, adaptive damping smooth switching, switching interlocking, and post-switching interlocking. This comprehensively improves power supply safety and reliability through a five-layer architecture: accurate detection, adaptive damping smooth execution, pre-locking safety interlocking, post-locking interlocking, and remote operation and maintenance. It automatically performs equipment inspection and predictive maintenance based on real-time data acquisition; under normal operating conditions, manual switching modes / transfer operations are also supported. Please refer to [link / reference]. Figure 1 and Figure 2 The technical solution adopted in the specific embodiment of the present invention is as follows: a low-voltage power supply automatic transfer device, comprising: Main incoming power supply 1; Backup power supply 2; It is suitable for high-reliability power supply scenarios such as 0.4kV industrial power distribution, data centers, medical buildings, precision equipment, and photovoltaic-storage microgrids.

[0018] The main circuit breaker 3 is connected to the main incoming power supply 1; The backup circuit breaker 4 is connected to the backup incoming power supply 2; Low-voltage busbar 5; Electrical equipment 14 is connected to the main incoming power supply 1 and the backup incoming power supply 2 via the low-voltage busbar 5 through the main circuit breaker 3 and the backup circuit breaker 4 respectively. Existing ordinary switching devices suffer from large impact and power failure, as well as the shortcomings of existing damping smooth switching modules such as low detection accuracy, non-adjustable damping, lack of perfect interlocking, low integration and lack of remote operation and maintenance.

[0019] Also includes: The damping switching module 6 comprises an adjustable non-inductive damping resistor, an adjustable reactance, and a thyristor switching mechanism. The damping switching module 6 is connected across the main circuit breaker 3 and the standby circuit breaker 4. It collects load current, phase difference, and harmonic data in real time and adjusts the damping resistance and reactance parameters based on the collected information. It employs a short-time closing-loop control sequence (closing first, then opening) to actively suppress transient circulating current during closing. Unlike commercially available fixed-parameter damping modules, this invention specifically integrates an adjustable non-inductive damping resistor, a high-precision adjustable reactance, and a high-speed thyristor switching mechanism into a single module, connected across the outgoing lines of the main and standby circuit breakers.

[0020] The oscillation suppression control unit 7 detects circuit oscillations and outputs an adjustment amount that is inversely phase to the oscillation, thereby canceling out the oscillation energy. The detection unit 10 includes: a synchronous sampling chip, a PT / CT, a contact temperature sensor, and a micro resistance detection module. The detection unit 10 collects the three-phase voltage, current, phase, frequency, and harmonics of the main incoming power supply 1, the backup incoming power supply 2, and the low-voltage bus 5, and determines the contact temperature, circuit contact resistance, and operating current of the opening and closing coils of the main circuit breaker 3 and the backup circuit breaker 4. The interlocking logic unit 8 determines the interlocking status of asynchronous interlocking, incoming line overcurrent fault interlocking, circuit breaker position abnormal interlocking, sampling circuit disconnection / distortion interlocking, reverse power flow interlocking, and local / remote manual maintenance interlocking. After triggering, it disables the damping switching module 6; this is a built-in six independent interlocking criterion in the specific embodiment of the present invention.

[0021] The primary and backup interlocking unit 9 includes a dual redundancy architecture of hardware electrical interlocking and software logic interlocking. The hardware electrical interlock is cross-hard interlocked with the contacts of the main circuit breaker 3 and the backup circuit breaker 4. After any circuit breaker is closed, the closing control circuit of the other circuit breaker is physically cut off. After the software logic interlock switch is completed, it permanently blocks the other closing output command, keeping the interlock state effective. It is released when the power grid power supply is restored to normal or a manual reset command is issued. The main control unit 11 communicates with the main circuit breaker 3, the backup circuit breaker 4, the damping switching module 6, the oscillation suppression control unit 7, the detection unit 10, the interlocking logic unit 8, and the main / backup interlocking unit 9. The main control unit 11 is an industrial-grade dual-core processor with built-in high-precision data filtering, synchronous phase locking, damping parameter adaptive adjustment, switching interlocking discrimination, post-switching interlocking control, and fault analysis algorithms. It coordinates the detection of the entire device, smooth damping switching, interlocking, and interlocking timing control.

[0022] Communication unit 12 is connected to the main control unit 11 by signal, outputs and displays control parameters, and provides control commands; The auxiliary power supply unit 13 provides separate control power to the damping switching module 6, the oscillation suppression control unit 7, the interlocking logic unit 8, the main and backup interlocking unit 9, and the detection unit 10. It is a wide voltage adaptive power supply module with power failure retention capability to ensure that the status, interlocking, interlocking, and event records of the damping module are not lost when the device loses power.

[0023] In some embodiments, preferably, this is to achieve high-precision synchronous monitoring of all dimensions of power grid electrical quantities and switch body status. The detection unit 10 has a voltage detection accuracy of ≤ ±0.05%, a current detection accuracy of ≤ ±0.1%, a temperature detection accuracy of ≤ ±0.2℃, and a contact resistance resolution of ≤ 0.5μΩ.

[0024] In some preferred embodiments The damping switching module 6 completes the power-off-free and circulating current-free switching in 15ms-25ms, and automatically trips and locks out upon timeout. It also completes a smooth load transfer in 15-25ms, actively suppressing loop-closing transient circulating current, achieving seamless load switching without power outages, circulating current, or voltage surges. The module has built-in switching timing logic and loop-closing timeout protection, automatically forcibly tripping upon timeout to avoid long-term parallel operation.

[0025] In other embodiments, preferably, The detection unit 10 includes a 24-bit ultra-high precision synchronous sampling chip.

[0026] In other embodiments, preferably, The main control unit 11 includes: an industrial-grade dual-core processor, with built-in data filtering, synchronous phase-locking, damping parameter adaptive adjustment, switching interlocking discrimination, post-switching interlocking control, fault analysis program, control detection, damping switching, interlocking, and interlocking timing.

[0027] In other embodiments, preferably, The communication unit 12 integrates Ethernet, wireless communication and industrial bus interfaces, and can remotely transmit real-time parameters, the damping switching module 6, smooth switching events, locking reasons, interlock status and fault recordings, and supports remote parameter setting and remote operation and maintenance.

[0028] A control method for the low-voltage power supply automatic transfer device includes the following steps: The low-voltage power supply automatic transfer device is initialized upon power-up, and completes hardware self-test, sampling channel calibration, damping module switching self-test, and interlocking logic and interlocking circuit self-test. The detection unit 10 synchronously collects power grid electrical parameters, status parameters of the main circuit breaker 3 and the standby circuit breaker 4, and grid-connected operation parameters of the electrical equipment 14 in real time. The main control unit 11 performs filtering calculations on the collected data, power quality analysis, and equipment health assessment, and simultaneously performs pre-switching interlocking condition judgment; when the main control unit 11 detects that the interlocking condition has been triggered, it immediately blocks the damping switching outlet, records the interlocking reason and sends it remotely, and returns to the loop monitoring. When there is no triggering lockout condition, the main incoming power supply 1 is abnormal or the health deterioration of the main circuit breaker 3 exceeds the threshold, the main control unit 11 initiates the automatic transfer process, and the backup incoming power supply 2 synchronizes the amplitude, frequency and phase of the main incoming power supply 1 and closes the backup circuit breaker 4. After the load is completely transferred, disconnect the main circuit breaker 3 and deactivate the damping switching module 6.

[0029] Preferably, the following steps are also included: After the switchover is completed, the main and backup interlocking unit 9 is activated to forcibly lock the closing circuit of the main circuit breaker 3 or the backup circuit breaker 4. The interlock status remains in effect until the power grid returns to normal or a manual reset is performed.

[0030] Preferably, the following steps are also included: The communication unit 12 uploads detection data, switching records, locking events, and interlock status throughout the process, enabling remote monitoring and traceability maintenance.

[0031] In specific operation: both the main incoming power supply 1 and the backup incoming power supply 2 are connected to the electrical equipment 14. When the main incoming power supply 1 is abnormal, the damping switching module 6 adjusts the damping resistance and reactance parameters according to the real-time collected load current, phase difference, and harmonic data. It adopts a short-time closing loop control sequence of closing before opening to actively suppress the closing loop transient circulating current. The blocking logic unit 8 judges the non-synchronous blocking, incoming line overcurrent fault blocking, circuit breaker position abnormal blocking, sampling circuit disconnection / distortion blocking, reverse power flow blocking, and local / remote manual maintenance blocking status. After triggering, the damping switching module 6 is disabled. The detection unit 10 synchronously samples the chip, PT / CT, contact temperature sensor, and micro resistance detection module. The detection unit 10 collects the three-phase voltage, current, phase, frequency, and harmonics of the main incoming power supply 1, backup incoming power supply 2, and low-voltage bus 5, and judges the contact temperature, circuit contact resistance, and opening and closing coil operating current of the main circuit breaker 3 and the backup circuit breaker 4. The main control unit 11 performs filtering calculations on the collected data, power quality analysis, and equipment health assessment. Simultaneously, it executes pre-switching interlocking condition judgment. When no interlocking condition is triggered, the automatic transfer procedure is initiated. The backup incoming power supply 2 synchronizes with the main incoming power supply 1 in amplitude, frequency, and phase. After the backup circuit breaker 4 is closed and the load is completely transferred, the main circuit breaker 3 is disconnected, and the damping switching module 6 is deactivated. The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A low-voltage power supply automatic transfer device, comprising: Main incoming power supply (1); Backup power supply (2); The main circuit breaker (3) is connected to the main incoming power supply (1); The backup circuit breaker (4) is connected to the backup incoming power supply (2); Low-voltage busbar (5); The electrical equipment (14) is connected to the main incoming power supply (1) and the backup incoming power supply (2) respectively through the main circuit breaker (3) and the backup circuit breaker (4) via the low-voltage bus (5); Its characteristic is that it further includes: The damping switching module (6) is a module including: an adjustable non-inductive damping resistor, an adjustable reactance, and a thyristor switching mechanism. The damping switching module (6) is connected across the main circuit breaker (3) and the backup circuit breaker (4). The load current, phase difference, and harmonic data are collected in real time. The damping resistance and reactance parameters are adjusted according to the collected information. The short-time closing loop control sequence of closing before opening is adopted to actively suppress the closing loop transient circulating current. The oscillation suppression control unit (7) detects circuit oscillation and outputs an adjustment amount that is inverse to the oscillation to counteract the oscillation energy; The detection unit (10) includes: a synchronous sampling chip, a PT / CT, a contact temperature sensor, and a micro resistance detection module. The detection unit (10) collects the three-phase voltage, current, phase, frequency, and harmonics of the main incoming power supply (1), the backup incoming power supply (2), and the low-voltage bus (5), and determines the contact temperature, circuit contact resistance, and operating current of the opening and closing coils of the main circuit breaker (3) and the backup circuit breaker (4). The interlocking logic unit (8) determines the interlocking status of asynchronous interlocking, incoming line overcurrent fault interlocking, circuit breaker position abnormal interlocking, sampling circuit disconnection / distortion interlocking, reverse power flow interlocking, and local / remote manual maintenance interlocking. After triggering, the damping switching module (6) is disabled. The primary and backup interlocking unit (9) includes a dual redundancy architecture of hardware electrical interlocking and software logic interlocking. The hardware electrical interlock is cross-interlocked with the contacts of the main circuit breaker (3) and the backup circuit breaker (4). After any circuit breaker is closed, the closing control circuit of the other circuit breaker is physically cut off. After the software logic interlock switch is completed, it permanently blocks the other closing output command, keeping the interlock state effective. It is released when the power grid power supply is restored to normal or a manual reset command is issued. The main control unit (11) communicates with the main circuit breaker (3), the backup circuit breaker (4), the damping switching module (6), the oscillation suppression control unit (7), the detection unit (10), the interlocking logic unit (8), and the main and backup interlocking unit (9); The communication unit (12) is connected to the main control unit (11) by signal, outputs and displays control parameters, and provides control commands; The auxiliary power supply unit (13) provides separate control power to the damping switching module (6), the oscillation suppression control unit (7), the interlocking logic unit (8), the main and backup interlocking unit (9), and the detection unit (10).

2. The low-voltage power supply automatic transfer device according to claim 1, characterized in that, The detection unit (10) has a voltage detection accuracy of ≤ ±0.05%, a current detection accuracy of ≤ ±0.1%, a temperature detection accuracy of ≤ ±0.2℃, and a contact resistance resolution of ≤ 0.5μΩ.

3. The low-voltage power supply automatic transfer device according to claim 1, characterized in that, The damping switching module (6) completes the switching without power outage and without circulating current in 15ms-25ms, and automatically trips and locks out after the timeout.

4. The low-voltage power supply automatic transfer device according to claim 1, characterized in that, The detection unit (10) includes a 24-bit ultra-high precision synchronous sampling chip.

5. The low-voltage power supply automatic transfer device according to claim 1, characterized in that, The main control unit (11) includes: an industrial-grade dual-core processor with built-in data filtering, synchronous phase-locking, damping parameter adaptive adjustment, switching interlocking discrimination, post-switching interlocking control, fault analysis program, control detection, damping switching, interlocking, and interlocking timing.

6. The low-voltage power supply automatic transfer device according to claim 1, characterized in that, The communication unit (12) integrates Ethernet, wireless communication and industrial bus interfaces, and can remotely send real-time parameters, the damping switching module (6), smooth switching events, locking reasons, interlock status, fault recordings, and supports remote parameter setting and remote operation and maintenance.

7. A control method for a low-voltage power supply automatic transfer device according to any one of claims 1-6, characterized in that, Includes the following steps: The low-voltage power supply automatic transfer device is initialized upon power-up, and completes hardware self-test, sampling channel calibration, damping module switching self-test, and interlocking logic and interlocking circuit self-test. The detection unit (10) collects in real time the electrical parameters of the power grid, the status parameters of the main circuit breaker (3) and the backup circuit breaker (4), and the grid-connected operation parameters of the electrical equipment (14). The main control unit (11) performs filtering calculations on the collected data, power quality analysis and equipment health assessment, and simultaneously performs pre-switching interlocking condition judgment; when the main control unit (11) detects the triggering interlocking condition, it immediately blocks the damping switching outlet, records the interlocking reason and sends it remotely, and returns to the loop monitoring. When there is no triggering lockout condition, the main incoming power supply (1) is abnormal or the health of the main circuit breaker (3) deteriorates beyond the threshold, the main control unit (11) initiates the automatic transfer process, and the backup incoming power supply (2) synchronizes the amplitude, frequency and phase of the main incoming power supply (1) and closes the backup circuit breaker (4). After the load is completely transferred, disconnect the main circuit breaker (3) and deactivate the damping switching module (6).

8. The control method for the low-voltage power supply automatic transfer device according to claim 7, characterized in that, It also includes the following steps: After the switch is completed, the main and backup interlocking unit (9) is activated to forcibly lock the closing circuit of the main circuit breaker (3) or the backup circuit breaker (4); The interlock status remains in effect until the power grid returns to normal or a manual reset is performed.

9. The control method for the low-voltage power supply automatic transfer device according to claim 7, characterized in that, It also includes the following steps: The communication unit (12) uploads detection data, switching records, locking events and interlock status throughout the process, realizing remote monitoring and traceability maintenance.

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