A low-voltage uninterrupted meter changing control method based on double-channel non-inductive switching

Abstract

This invention discloses a low-voltage uninterrupted power meter replacement control method based on dual-channel seamless switching, comprising: connecting a dedicated device in parallel to the incoming and outgoing line circuits of the energy meter to be replaced through a universal connecting component to obtain a bypass channel; the main control unit automatically performs phase identification and safety verification of circuit parameters to ensure correct wiring and that the system status meets preset stability conditions; when the system status meets the preset stability conditions, the main control unit switches the user load current from the old energy meter channel to the bypass channel within a preset time using a first-on, then-off timing logic; the bypass channel continuously supplies power to the load, while the main control unit simultaneously monitors the circuit current and contact temperature throughout the process; during the bypass channel power supply, the old energy meter is removed and a new energy meter is installed; after confirming that the wiring of the new energy meter is correct, the main control unit performs a reverse switch to restore the user load current from the bypass channel to the new energy meter channel, measures the power consumption during the bypass channel power supply, and encrypts and stores the corresponding power data.

Description

Technical Field

[0001] This invention relates to the field of low-voltage uninterrupted power supply (UDPS) technology, and more specifically, to a low-voltage uninterrupted power supply meter replacement control method based on dual-channel seamless switching. Background Technology

[0002] The principle behind uninterrupted meter replacement technology is relatively simple. It primarily involves adding an external bypass circuit to short-circuit the incoming and outgoing terminals of the electricity meter, thus achieving uninterrupted meter replacement. Taking a single-phase electricity meter as an example, the phase current enters from terminal 1 and flows out from terminal 2; the neutral current enters from terminal 3 and flows out from terminal 4. By short-circuiting the phase and neutral terminals of the meter to be replaced, the old meter can be removed and the new meter installed without interrupting power.

[0003] Depending on the implementation method, there are two main categories of uninterrupted meter replacement technology solutions: (1) Uninterrupted meter replacement solution for newly installed meter boxes. This solution is implemented through connectors with built-in uninterrupted meter replacement function. This solution is convenient to operate and safe to use, but its application depends on newly installed meter boxes or prefabricated and modified meter boxes. Considering that the large number of old meter boxes currently in operation have not been equipped with uninterrupted meter replacement connectors, this solution has significant limitations in application scenarios.

[0004] (2) Uninterrupted meter replacement solution for existing meter boxes. This is achieved through a dedicated uninterrupted meter replacement device. Maintenance personnel install the uninterrupted meter replacement circuit on-site to complete the meter replacement operation. This solution is highly adaptable to various scenarios and is applicable to both non-connector meter boxes and meter boxes without uninterrupted meter replacement connectors currently in operation.

[0005] The existing technical approach involves using a meter mounting connector with basic bypass functionality. These devices may integrate a manually or electrically operated bypass switch. During uninterrupted meter replacement work, maintenance personnel use a shorting tool provided by the manufacturer to directly connect to the pre-installed short interface on the connector, ensuring full contact between the elastic copper contacts on both sides of the short connector and the bottom of the connector's copper posts, thereby creating a current loop and short-circuiting the meter.

[0006] The existing technical solutions have the following main drawbacks: (1) Poor applicability to existing old meter boxes: Existing technologies usually require the meter box to have prefabricated interfaces for modification or sufficient operating space. For a large number of existing old meter boxes of various specifications, it is often impossible to achieve "plug and play", the modification and adaptation cost is extremely high, and it is difficult to promote on a large scale, thus limiting the scope of popularization of uninterrupted meter replacement technology.

[0007] (2) There are perceived risks in the switching process: Schemes that rely on mechanical manual switching or simple relays have a slow switching speed and cannot achieve a "seamless" experience for the user. Some schemes have a switching time of up to minutes, and users may still experience short-term power outages or voltage fluctuations.

[0008] (3) There are blind spots in electricity metering during meter replacement: Most existing bypass solutions lack independent and accurate metering functions. During bypass power supply, the actual electricity consumed by users cannot be accurately recorded, resulting in electricity loss. Subsequent electricity fee refunds can only rely on estimation or negotiation with users, lacking accurate data support, which can easily lead to disputes and cannot meet the needs of lean management.

[0009] (4) The safety protection system is passive and imperfect: The safety guarantee of existing technologies relies heavily on mechanical anti-misoperation design (such as anti-misinsertion structure) and the experience and caution of operators. There is a general lack of proactive intelligent identification of phase and misconnection, and real-time status monitoring. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a low-voltage uninterrupted meter replacement control method based on dual-channel seamless switching.

[0011] According to one aspect of the present invention, a low-voltage uninterrupted meter switching control method based on dual-channel seamless switching is provided, comprising: The special device is connected in parallel to the incoming and outgoing circuits of the energy meter to be replaced through a universal connection component to obtain a bypass channel; The main control unit automatically performs phase identification and loop parameter safety verification to ensure that the wiring is correct and the system status meets the preset stability conditions. When the system status meets the preset stability conditions, the main control unit switches the user load current from the old energy meter channel to the bypass channel within a preset time through the turn-on-then-off timing logic. The bypass channel continuously supplies power to the load, while the main control unit simultaneously monitors the circuit current and contact temperature throughout the process. During the bypass channel power supply period, the old energy meter is removed and a new energy meter is installed. After confirming that the wiring of the new energy meter is correct, the main control unit performs a reverse switch, restoring the user's load current from the bypass channel to the new energy meter channel, measuring the power consumption during the bypass channel power supply period, and encrypting and storing the corresponding power data.

[0012] Optionally, the specific implementation of phase recognition is as follows: Simultaneously acquire the three-phase voltage signals on the incoming side and the three-phase voltage signals on the outgoing side; The fundamental amplitude and phase of each phase signal in the three-phase voltage signals on the incoming and outgoing sides are extracted using Discrete Fourier Transform. Calculate the phase difference or Pearson correlation coefficient between the corresponding phase signals on the incoming and outgoing sides based on the fundamental amplitude and phase of each phase signal; Phase recognition is considered complete when the phase difference is less than a preset threshold or the Pearson correlation coefficient meets a preset condition.

[0013] Optionally, the formula for calculating the phase difference is: , where Δ t The time difference between the zero-crossing points of the incoming and outgoing voltages. T The power frequency cycle is used; the preset threshold value range is ±5°. Pearson correlation coefficient r pM The calculation formula is: in u s ( k () represents the incoming line voltage sequence. u M ( k () represents the outgoing line voltage sequence. Np This represents the number of sampling points.

[0014] Optionally, in the sequential logic of "on first, off later", the load switch closing signal of the main control unit controls the bypass channel to precede the old energy meter channel opening signal, forming a current parallel transfer zone of 1ms to 3ms, so that the load current is powered through two parallel paths during the switching period, achieving uninterrupted switching.

[0015] Optionally, the switching instructions of the turn-on-then-off timing logic strictly follow the sequence of phase identification completion → channel status confirmation → timing pulse triggering, and the triggering point of the timing pulse is synchronized with the zero-crossing point of the grid voltage.

[0016] Optionally, the total switching time T total It is determined by the superposition of the following components: in, T detect For phase identification and security status confirmation time, T logic The timing of internal logic processing and instruction issuance within the main control unit. T drive For the response and setup time of the drive circuit, T contact This refers to the physical action time of the switching element.

[0017] Optionally, safety verification includes overcurrent monitoring and overtemperature monitoring, specifically implemented as follows: Overcurrent monitoring uses an open-loop Hall current sensor or a closed-loop current transformer to non-contactly measure the loop current. When the loop current exceeds a preset current threshold, protection is triggered. Over-temperature monitoring monitors the contact temperature by installing temperature sensors at the contact points of the incoming and outgoing line connectors. Protection is triggered when the temperature of any contact point exceeds a preset temperature threshold. Multi-sensor differential monitoring is adopted. When the absolute value of the difference between any two temperature sensor readings exceeds the preset temperature difference abnormality threshold, a temperature difference abnormality alarm is triggered.

[0018] Optionally, after the safety verification conditions are met, the six-state machine embedded in the main control unit performs state transitions in the following order before allowing closing: State 1, the system enters the initialization / self-test state upon power-up: after the main control unit starts up, it performs a readback self-test on all sensors, memory and communication interfaces. If the self-test fails, it jumps to the fault lockout state and alarms. State 2, after passing the self-test, enters the phase recognition state: the phase recognition algorithm is started, and the voltage signals of the incoming and outgoing sides are collected and analyzed; State 3: After phase recognition is completed, the phase recognition correct flag is set, and the real-time monitored current is simultaneously... I and temperature T With preset threshold I set , T set Compare; State 4: When the "phase recognition correct" flag is valid, I < I set , T < T set A state transition is executed when five conditions are met: hardware interlock and gate input are valid, temperature difference monitoring does not exceed the threshold. State 5, jump to the allowed closing state: The main control unit sends an enable signal and a closing pulse sequence to the drive circuit, the main circuit is connected, and the equipment enters the normal operation mode; Continuous monitoring is performed while the circuit is allowed to close. If any monitored parameter exceeds the limit, the drive enable signal is immediately revoked and the circuit is forcibly switched to the fault lockout state.

[0019] Optionally, the hardware interlock AND gate is a multi-input AND gate. The inputs of the multi-input AND gate include a phase recognition correct signal, a voltage monitoring normal signal, a current monitoring normal signal, and a mechanical connection in place detection signal. The multi-input AND gate only outputs a drive enable signal when all inputs are at a valid level.

[0020] Optionally, the electricity data is uniquely associated with a specific user and the current meter replacement operation through the meter replacement work order number, the old meter asset code, and the new meter asset code, and is exported to the marketing business system via Bluetooth or RS485 interface as the metering basis for electricity fee refunds and subsidies.

[0021] According to another aspect of the present invention, a low-voltage uninterrupted meter replacement control device based on dual-channel seamless switching is provided, comprising: a main control unit, an old energy meter channel, a bypass channel, a sensing and monitoring module, a safety actuator, and a data storage and communication module; The main control unit is connected to the old energy meter channel, bypass channel, sensor monitoring module, safety actuator and data storage and communication module respectively, and is used to execute switching logic, safety monitoring and data processing. The sensing and monitoring module is used to collect electrical parameters on the incoming and outgoing sides, as well as temperature parameters of key contacts; The safety actuator is used to switch the circuit on and off and output alarms according to the control commands of the main control unit; The data storage and communication module is used to store operation logs and interact with external systems.

[0022] Therefore, this invention provides a low-voltage uninterrupted meter replacement control method based on dual-channel seamless switching. A dedicated device is connected in parallel to the incoming and outgoing circuits of the meter to be replaced via a universal connecting component, creating a bypass channel. The main control unit automatically performs phase identification and circuit parameter safety verification to ensure correct wiring and that the system status meets preset stability conditions. When the system status meets the preset stability conditions, the main control unit, through a first-on, then-off timing logic, switches the user load current from the old meter channel to the bypass channel within a preset time. The bypass channel continuously supplies power to the load, while the main control unit simultaneously monitors the circuit current and contact temperature. During the bypass channel power supply, the old meter is removed and a new meter is installed. After confirming that the new meter wiring is correct, the main control unit performs a reverse switch, restoring the user load current from the bypass channel to the new meter channel. The power consumption during the bypass channel power supply is measured, and the corresponding power data is encrypted and stored. This method aims to safely, quickly, and accurately complete the replacement of single-phase and three-phase meters without modifying existing old meter boxes or interrupting user power supply. Attached Figure Description

[0023] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a flowchart illustrating a low-voltage uninterrupted meter replacement control method based on dual-channel seamless switching, provided by an exemplary embodiment of the present invention. Detailed Implementation

[0024] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0025] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0026] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0027] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0028] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0029] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0030] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0031] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0032] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0033] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0035] Figure 1 This is a flowchart illustrating a low-voltage uninterrupted meter replacement control method based on dual-channel seamless switching, provided in an exemplary embodiment of the present invention. Figure 1 As shown, the low-voltage uninterrupted meter replacement control method 100 based on dual-channel seamless switching includes the following steps: Step 101: Connect the special device in parallel to the incoming and outgoing circuits of the energy meter to be replaced through a universal connection component to obtain a bypass channel; Step 102: The main control unit automatically performs phase identification and loop parameter safety verification to ensure that the wiring is correct and the system status meets the preset stability conditions. Step 103: When the system status meets the preset stability conditions, the main control unit switches the user load current from the old energy meter channel to the bypass channel within a preset time through the timing logic of first turning on and then turning off. Step 104: The bypass channel continuously supplies power to the load. The main control unit simultaneously monitors the circuit current and contact temperature throughout the process. During the bypass channel power supply, the old energy meter is removed and a new energy meter is installed. Step 105: After confirming that the wiring of the new energy meter is correct, the main control unit performs a reverse switch to restore the user load current from the bypass channel to the new energy meter channel, measures the power consumption during the bypass channel power supply, and encrypts and stores the corresponding power data.

[0036] Specifically, this invention provides a dedicated device and control method for uninterrupted meter replacement based on dual-channel seamless switching. It aims to safely, quickly, and accurately complete the replacement of single-phase and three-phase energy meters without modifying existing old meter boxes or interrupting the user's power supply. This invention mainly solves the following five technical problems: (1) Poor compatibility of existing meter boxes: For the massive number of existing old meter boxes, a tool-based implementation plan that requires no modification and is plug-and-play is provided to reduce modification costs and implementation threshold; (2) Insufficient power supply continuity: Overcome the shortcomings of traditional solutions with long switching time (minutes) that cause users to perceive power outages, and achieve a true "zero power outage" experience on the user side; (3) Power loss during meter replacement period: Overcome the problem of power loss caused by metering gaps during meter replacement period, and provide reliable data support for accurate electricity bill calculation; (4) Passive safety protection for operations: Change the existing safety mode that is mainly based on passive protection, and build a multi-layered safety protection system with active prediction and intelligent interlocking functions; (5) Weak field connection versatility: solves the problem that traditional connection components are difficult to reliably connect in non-standard or space-constrained wiring environments, and improves the field adaptability of the device.

[0037] 1. Hardware System Composition The dedicated device is a portable tooling unit integrating control, metering, protection, and communication functions. Its core electrical principle module includes: (1) Main control unit (MCU): responsible for running phase recognition algorithm, switching logic, security monitoring algorithm and data processing.

[0038] (2) Dual power supply channels: including the operating channel and the bypass channel. The operating channel is the power supply path that connects to the user's existing electricity meter; the bypass channel is an independent power supply path built inside the device and connected in parallel with the operating channel. It integrates a high-precision metering module and a bypass load switch (such as a contactor).

[0039] (3) Sensing and monitoring module: voltage / current monitoring channel, which can collect voltage and current signals of the incoming side (power supply) and outgoing side (load) in real time; temperature sensor, deployed at key contacts such as incoming / outgoing connectors, with a monitoring accuracy of ±1℃, used to calculate temperature rise.

[0040] (4) Safety actuators: including controlled high-speed relays (or contactors), status indicator LEDs and alarm units.

[0041] (5) Data storage and communication module: The built-in memory can store no less than 200 operation logs (including power data) and retain them for no less than 2 years after power failure; it supports multiple communication interfaces such as Bluetooth and RS485. The communication module must support the national cryptographic algorithms SM1, SM2, SM3, SM4, SM7 and SM9 and pass the test of the State Cryptography Administration.

[0042] 2. Uninterrupted meter replacement method based on the above hardware system Step 1: Establish a bypass. The device is connected in parallel to the incoming and outgoing circuits of the energy meter to be replaced via a universal connection component, providing a stable electrical path for subsequent current switching.

[0043] Step 2: Electrical safety verification. The MCU automatically performs phase identification and circuit parameter safety verification to ensure that the wiring is correct and the system status meets the preset stability conditions (these conditions are set by the user based on the application scenario), thus establishing a safe prerequisite for subsequent switching.

[0044] Step 3: Ultra-fast switching. The MCU uses precise timing logic of "on first, off later" to seamlessly switch the user's load current from the old energy meter channel to the device bypass channel within ≤40ms, without the user noticing.

[0045] Step 4: Safe Meter Replacement. The bypass channel continuously supplies power to the load, while the device simultaneously monitors the circuit current and temperature throughout the process, providing operators with a safe window to remove the old meter and install the new one.

[0046] Step 5: Resumption Switching and Data Archiving. After confirming that the new meter wiring is correct, the MCU performs a reverse switch, restoring the current to the new meter channel. The system meters the power consumption during the bypass period and encrypts and stores the data for subsequent accurate electricity billing, ensuring a complete closed loop of metering and management.

[0047] Seamless switching between dual channels This invention employs a dual guarantee mechanism of "mechanical linkage + electronic control" to achieve ultra-fast and seamless switching of ≤40ms. The details of its core technology implementation are as follows: 1. MCU Control Logic and Algorithm The control logic employs a timing pulse generation algorithm based on a state machine and a high-precision hardware timer. The release of the switching command strictly follows a three-step logic: "phase identification completed → channel status confirmed → timing pulse triggered," ensuring that the action trigger point is synchronized with the zero-crossing point of the grid voltage to minimize transient inrush current.

[0048] 2. Drive circuit design There are two ways to implement the drive circuit: (1) Solid-state relay (SSR) drive: If a solid-state relay is selected as the actuator, the drive circuit adopts a combination of optocoupler isolation and power MOSFET / IGBT. For example, the 3.3V / 5V logic signal of the MCU is isolated and converted into the drive side voltage through a high-speed optocoupler (such as 6N137), and then the gate of the MOSFET is driven to control the large current switching.

[0049] (2) High-speed magnetic latching relay drive: If a magnetic latching relay is selected, the drive circuit needs to generate a momentary high voltage and high current pulse to change the state of its permanent magnet (set / reset). The circuit is usually composed of an energy storage capacitor, an H-bridge driver chip (such as L298N) and a discharge circuit to ensure that sufficient momentary drive energy can be provided to the relay coil under the control of the MCU pulse signal.

[0050] 3. Implementation of Phase Synchronization Algorithm (1) Hardware configuration The core hardware of the phase automatic recognition module includes: 1) Voltage signal acquisition: The high-voltage signal of the power grid is converted into a low-voltage signal that can be processed by the MCU through a high-precision resistor divider network and voltage transformer (PT).

[0051] 2) Signal conditioning: Operational amplifiers are used to construct signal follower and filter circuits to filter out high-frequency noise.

[0052] 3) Zero-crossing detection (ZCD): A high-speed comparator (such as LM311) is used to convert a sinusoidal voltage signal into a square wave signal, and the rising / falling edge corresponds to the zero-crossing point of the voltage.

[0053] (2) Software Algorithm 1) Switching time calculation formula Total switching time It is determined by the combination of the following factors: in: The phase identification and safety status confirmation time is typically 10-20ms. This step is deeply integrated with the "prevention" and "process monitoring" of the four-layer safety protection system. The system will only start the switching timer after phase identification is completed and the intelligent interlocking system is in the "allow closing" state. This refers to the time for internal logic processing and instruction issuance within the MCU, including the global timing scheduling and token verification process in the intelligent interlocking linkage technology based on multi-timing collaboration, which takes less than 1ms. For the response and setup time of the drive circuit, solid-state relays take about 0.1-1ms, and magnetic latching relays take about 2-5ms. For the physical action time of switching elements, solid-state relays have almost zero time, while high-quality magnetic latching relays have ≤5ms.

[0054] 2) Phase recognition implementation The MCU calculates the input line voltage by capturing the edge of the zero-crossing detection signal. U in ) and outgoing line voltage ( U out The algorithm first performs digital filtering on the signal, then uses cross-correlation or measures the zero-crossing time difference (Δ). t The phase difference is calculated using the following method: Where T is the power frequency period (20ms). The threshold for determining phase synchronization is Δ. The setting needs to be based on system tolerance. The specific method is not a simple absolute value, but should combine signal quality and zero-crossing jitter tolerance. The determination formula is: |Δ |≤Δ , usually Δ Set it to ±5∘.

[0055] The "phase recognition complete" signal serves as a key condition for the transition of the "intelligent interlocking state machine"; conversely, the "safety interlocking" state will hardware-disable the output of switching pulses. Through bus interaction within the MCU and hardware interlocking circuitry, a deep balance between safety and speed is achieved, ensuring that any switching action is executed under absolutely safe electrical and logical conditions.

[0056] 3) Implementation of the "first on, then off" mechanism circuit The core circuit involves controlling the pulse width of two PWM signals via an MCU at the drive terminals of the dual relays (K1 for bypass and K2 for operation) to control the accuracy Δ.t min Timing ensures the closure signal of K1. Slightly ahead of the disconnect signal of K2 The timing arrangement must satisfy: ,in The effective pulse width driven by K1.

[0057] During the overlap time (typically designed to be 1-3ms), the bypass channel K1 is closed while the operating channel K2 is not yet open, and the load current is supplied through the two parallel paths. Subsequently, K2 is opened, and all current is transferred to the K1 path, achieving uninterrupted switching. The essence of this mechanism is to create a temporary current parallel transfer zone, completely avoiding power interruption.

[0058] 3. Bypass Metering Compensation System Design The bypass power consumption data recorded by the device is uniquely linked to a specific user and the current meter replacement operation through information such as the meter replacement work order number and the asset codes of the old and new meters. The data can be exported via Bluetooth or RS485 interface and provided to the marketing business system as a basis for accurate refunds or additional payments to users' electricity bills, thereby eliminating metering blind spots and achieving a closed-loop management system.

[0059] 4. Work safety protection 1. Incorrect wiring protection The three-phase voltage signals of the incoming line (power supply side) and the outgoing line (load / meter side) are synchronously acquired through a high-precision resistor voltage divider network and voltage transformers. and After anti-aliasing filtering and ADC sampling, the signal undergoes digital filtering within the MCU. The fundamental amplitude and phase of each phase signal are extracted using Discrete Fourier Transform (DFT). Finally, analysis and identification are performed to calculate the Pearson correlation coefficient or phase difference between corresponding phase signals of the incoming and outgoing lines. The correlation coefficient calculation formula is as follows: Where u s (k), u M (k) represents the incoming and outgoing line voltage sequences, respectively. By comparing the correlation coefficient or phase difference, the system automatically matches the connection relationship of phases A / B / C with an accuracy of up to 100%.

[0060] In hardware, this is implemented through an enable interlock logic circuit. This circuit is essentially a multi-input AND gate, whose inputs include a phase identification correct signal, normal voltage / current monitoring signals for each phase, and a mechanical connection in-place detection signal. The AND gate only outputs a valid drive enable signal when all signals are validly high, thus preventing any unsafe connection operations from occurring at the hardware level.

[0061] 2. Overcurrent and overtemperature monitoring Current monitoring employs an open-loop Hall effect current sensor or a closed-loop current transformer (CT) for non-contact measurement, with an accuracy of ±2%. The signal conditioning circuit includes a regulated power supply, sampling resistors, an instrumentation amplifier, and a low-pass filter. Temperature monitoring utilizes K-type thermocouples or digital temperature sensors installed at key contacts, with an accuracy of ±1℃. To prevent localized hot spots from being ignored by averaging, multi-sensor differential monitoring is used, where the temperature difference between any two points is |Δ|. T | Exceeding the set threshold Δ T th At that time, a temperature difference alarm is triggered.

[0062] 3. Safety protection interlocking procedure All state transitions are controlled by the six-state machine embedded in the MCU, and their timeout is monitored by a hardware watchdog. The transition from safety interlocking to allowing closing must strictly follow the sequence of states in phase identification and obtain a positive result.

[0063] 1) Upon system power-up, the system enters the initialization / self-test state: The MCU starts and performs a readback self-test on all sensors, memory, and communication interfaces. If the self-test fails, the system jumps to the fault lockout state and triggers an alarm.

[0064] 2) Self-test passed, enter phase recognition state: Start phase recognition algorithm, collect and analyze incoming and outgoing line voltage signals, which takes about 10-20ms.

[0065] 3) Phase recognition completed and correct: The MCU sets the "Phase recognition correct" flag. Simultaneously, the real-time monitoring circuit continuously transmits current I and temperature T. i Parameters and preset current threshold I set Preset temperature threshold T set By comparison, the threshold determination function can be defined as follows: , where Δ T ij This represents the difference between any two temperature sensor readings.

[0066] 4) Comprehensive judgment of safety conditions: Only when the "phase recognition correct" flag is valid and all... I < I set ,all T < T set The system will only perform a state transition when five conditions are met: hardware interlock and gate input are valid, temperature differential monitoring does not exceed the threshold.

[0067] 5) When the conditions are met, the circuit jumps to the state where closing is allowed (working): The MCU sends an enable signal and a closing pulse sequence to the drive circuit, the main circuit is connected, and the equipment enters the normal working mode.

[0068] 6) Continuous monitoring during operation: In this state, the monitoring algorithm runs continuously. Once any monitored parameter exceeds the limit (I≥Iset or T≥Tset), the comparator hardware interrupt or software polling immediately triggers the protection logic.

[0069] 7) Fault Triggering and Locking: The MCU executes the preset instantaneous protection logic, immediately cancels the drive enable signal, forces the control state machine to jump to the fault lock state, outputs the lockout signal and records the fault code, and waits for manual reset.

[0070] In summary, the present invention has the following beneficial effects: 1. Achieve "zero power outages" on the user side and improve power supply reliability. Compared to the planned power outages of minutes (usually 3-10 minutes) caused by traditional meter replacement methods, and the brief interruptions that may occur with early simple bypass solutions, this invention uses mechanical linkage and electronic control to ensure that the switching time is strictly controlled within ≤40ms, which is lower than the threshold of human perception and equipment restart. This ensures that the user's precision electrical appliances, smart home devices, and continuous production processes are not affected, realizing the change from "short-term power outage" to "seamless switching".

[0071] 2. Overcame the problem of power loss during meter replacement, supporting accurate and fair electricity bill refunds and reimbursements. Traditional meter replacement procedures have a metering gap between the removal of the old meter and the commissioning of the new meter, resulting in lost electricity and insufficient grounds for refunds or compensation, which can easily lead to disputes. The "dual-channel" meter replacement solution proposed in this invention can accurately measure the user's electricity consumption in real time, continuously, and independently during bypass power supply.

[0072] 3. Improve the safety of meter replacement operations. This invention utilizes automatic phase identification technology and intelligent incorrect wiring protection logic to automatically check the phase before closing the circuit. Once a phase-to-phase incorrect connection is detected, it immediately locks out and issues an alarm, eliminating the risk of short circuits caused by wiring errors at the source. Simultaneously, it integrates overcurrent (±2% accuracy) and overtemperature (±1℃ accuracy) monitoring to monitor the circuit and contact status in real time. When the current exceeds a safety threshold (e.g., 40A) or the contact temperature rises abnormally, the system can immediately issue an alarm or perform protective disconnection. Through a logic control algorithm, it strictly adheres to the "on first, off later" switching sequence and ensures that the bypass switch will never malfunction before the power line is reliably connected, effectively preventing the risks of live plugging / unplugging and misoperation.

[0073] 4. Adapts to existing old meter boxes, achieving "no modification required" Addressing the challenges and high costs of retrofitting outdated meter boxes in my country, which are numerous, diverse in model, and often located in confined spaces, this solution employs a universal connection technology. By combining various compatible connectors such as piercing splitters, insulated alligator clips, and pre-installed connectors, it achieves safe and reliable plug-and-play functionality without requiring pre-fabrication modifications or wiring adjustments to existing meter boxes. This design breaks down the dependence of technical tools on on-site infrastructure, enabling uninterrupted meter replacement technology to be rapidly and economically deployed to all residential single-phase and industrial three-phase scenarios.

[0074] 5. Empowering digital and intelligent operation and maintenance, significantly improving operational efficiency and management level. The device records and transmits key data (time, electricity consumption, voltage, current, temperature, and event logs) for each meter replacement operation completely and securely to the back-end management system, enabling traceability of the operation process. All operations are verifiable, facilitating quality auditing and problem tracing. Meanwhile, standardized process guidance and status indicators reduce manual judgment and recording time, and the tool-based design makes meter replacement operations more standardized and efficient.

[0075] Furthermore, another embodiment of this application proposes a low-voltage uninterrupted meter switching control device based on dual-channel seamless switching, the device comprising: Main control unit, old energy meter channel, bypass channel, sensor monitoring module, safety actuator and data storage and communication module; The main control unit is connected to the old energy meter channel, bypass channel, sensor monitoring module, safety actuator and data storage and communication module respectively, and is used to execute switching logic, safety monitoring and data processing. The sensing and monitoring module is used to collect electrical parameters on the incoming and outgoing sides, as well as temperature parameters of key contacts; The safety actuator is used to switch the circuit on and off and output alarms according to the control commands of the main control unit; The data storage and communication module is used to store operation logs and interact with external systems.

[0076] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A low-voltage uninterrupted meter switching control method based on dual-channel seamless switching, characterized in that, include: The pre-set special device is connected in parallel to the incoming and outgoing circuits of the energy meter to be replaced through a universal connection component to obtain a bypass channel; The dedicated transposed main control unit automatically performs phase identification and loop parameter safety verification to ensure that the wiring is correct and the system status meets the preset stability conditions. When the system state meets the preset stability conditions, the main control unit switches the user load current from the old energy meter channel to the bypass channel within a preset time period through a preset turn-on-off timing logic. The bypass channel continuously supplies power to the load, and the main control unit simultaneously monitors the circuit current and contact temperature throughout the process. During the power supply period through the bypass channel, the old energy meter is removed and a new energy meter is installed. After confirming that the wiring of the new energy meter is correct, the main control unit performs a reverse switch to restore the user load current from the bypass channel to the new energy meter channel, measures the power consumption during the power supply period of the bypass channel, and encrypts and stores the corresponding power data.

2. The method according to claim 1, characterized in that, The specific implementation method of the phase recognition is as follows: Simultaneously acquire the three-phase voltage signals on the incoming side and the three-phase voltage signals on the outgoing side; The fundamental amplitude and phase of each phase signal in the three-phase voltage signals on the incoming side and the three-phase voltage signals on the outgoing side are extracted by using Discrete Fourier Transform. Based on the fundamental amplitude and phase of each phase signal, calculate the phase difference or Pearson correlation coefficient between the corresponding phase signals on the incoming and outgoing sides; When the phase difference is less than a preset threshold or the Pearson correlation coefficient meets a preset condition, the phase recognition is determined to be complete.

3. The method according to claim 2, characterized in that, The formula for calculating the phase difference is: , where Δ t The time difference between the zero-crossing points of the incoming and outgoing voltages. T The value is the power frequency cycle; the preset threshold value ranges from ±5°. The Pearson correlation coefficient r pM The calculation formula is: in, u s ( k () represents the incoming line voltage sequence. u M ( k () represents the outgoing line voltage sequence. k For sequence length, Np This represents the number of sampling points.

4. The method according to claim 1, characterized in that, In the aforementioned sequential logic of "open first, close later", the main control unit controls the load switch closing signal of the bypass channel to precede the disconnection signal of the old energy meter channel, forming a current parallel transfer zone of 1ms to 3ms, so that the load current is powered through two parallel paths during the switching period, achieving uninterrupted switching.

5. The method according to claim 4, characterized in that, The switching instruction of the first-to-close timing logic strictly follows the sequence of phase recognition completion → channel status confirmation → timing pulse triggering, and the triggering point of the timing pulse is synchronized with the zero-crossing point of the grid voltage.

6. The method according to claim 5, characterized in that, The total switching time T total It is determined by the superposition of the following components: in, T detect For phase identification and security status confirmation time, T logic The timing of internal logic processing and instruction issuance within the main control unit. T drive For the response and setup time of the drive circuit, T contact This refers to the physical action time of the switching element.

7. The method according to claim 1, characterized in that, The safety verification includes overcurrent monitoring and overtemperature monitoring, and the specific implementation method is as follows: The overcurrent monitoring measures the loop current non-contactly using an open-loop Hall current sensor or a closed-loop current transformer. When the loop current exceeds a preset current threshold, protection is triggered. The over-temperature monitoring system monitors the contact temperature by installing temperature sensors at the contact points of the incoming and outgoing line connectors. When the temperature of any contact point exceeds a preset temperature threshold, protection is triggered. Multi-sensor differential monitoring is adopted. When the absolute value of the difference between any two temperature sensor readings exceeds the preset temperature difference abnormality threshold, a temperature difference abnormality alarm is triggered.

8. The method according to claim 1, characterized in that, Once the safety verification conditions are met, the six-state machine embedded in the main control unit performs state transitions in the following order before allowing closing: State 1, the system enters the initialization / self-test state upon power-up: after the main control unit starts up, it performs a readback self-test on all sensors, memory and communication interfaces. If the self-test fails, it jumps to the fault lockout state and alarms. State 2, after passing the self-test, enters the phase recognition state: the phase recognition algorithm is started, and the voltage signals of the incoming and outgoing sides are collected and analyzed; State 3: After phase recognition is completed, the phase recognition correct flag is set, and the real-time monitored current is simultaneously... I and temperature T With preset threshold I set , T set Compare; State 4: When the "phase recognition correct" flag is valid, I < I set , T < T set A state transition is executed when five conditions are met: hardware interlock and gate input are valid, temperature difference monitoring does not exceed the threshold. State 5, jump to the allowed closing state: The main control unit sends an enable signal and a closing pulse sequence to the drive circuit, the main circuit is connected, and the equipment enters the normal operation mode; State 6: Continuously monitor the state where closing is permitted. If any monitored parameter exceeds the limit, immediately cancel the drive enable signal and force a jump to the fault lockout state.

9. The method according to claim 8, characterized in that, The hardware interlock AND gate is a multi-input AND gate. The inputs of the multi-input AND gate include a phase recognition correct signal, a voltage monitoring normal signal, a current monitoring normal signal, and a mechanical connection in place detection signal. The multi-input AND gate outputs a drive enable signal only when all inputs are at a valid level.

10. The method according to claim 1, characterized in that, The electricity data is uniquely associated with a specific user and the current meter replacement operation through the meter replacement work order number, the old meter asset code, and the new meter asset code. It is exported to the marketing business system via Bluetooth or RS485 interface as the metering basis for electricity fee refunds and subsidies.

11. A low-voltage uninterrupted power meter switching control device based on dual-channel seamless switching for implementing the method of any one of claims 1-10, characterized in that, include: Main control unit, old energy meter channel, bypass channel, sensor monitoring module, safety actuator and data storage and communication module; The main control unit is connected to the old energy meter channel, the bypass channel, the sensing and monitoring module, the safety actuator, and the data storage and communication module respectively, and is used to execute switching logic, safety monitoring, and data processing. The sensing and monitoring module is used to collect electrical parameters on the incoming and outgoing sides, as well as temperature parameters of key contacts. The safety actuator is used to switch the circuit on and off and output alarms according to the control instructions of the main control unit; The data storage and communication module is used to store operation logs and interact with external systems.

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