Self-adaptive processing method and system for reducing loop impedance

Abstract

The invention discloses a self-adaptive processing method and system for reducing loop impedance, and relates to the technical field of loop control, and the method comprises the steps: triggering a loop impedance suppression event after receiving a switching-out instruction when an electric energy meter operates with a load; aC voltage periodic signals are obtained through a voltage sampling loop, and a single-chip microcomputer determines a voltage zero crossing point time sequence position; by taking the zero crossing point time sequence as a constraint, generating a switching-out delay control quantity matched with the current period; and the load switch is controlled to be disconnected at the zero crossing point, so that contact separation occurs in a low-current interval, and self-adaptive suppression of current loop impedance is realized. The technical problems of large loop instantaneous current, serious heating, impedance rise and contact damage caused by non-zero-crossing disconnection of a built-in load switch electric energy meter during switching-out operation are solved, low-current disconnection is realized through adaptive detection of a voltage zero crossing point and accurate control of switching-out time, loop impedance rise is effectively inhibited, and the switching-out operation reliability is improved. Contact electric corrosion and heating are reduced, and the service life of the load switch is prolonged.

Description

Technical Field

[0001] This invention relates to the field of loop control technology, and specifically to an adaptive processing method and system for reducing loop impedance. Background Technology

[0002] With the continuous advancement of smart grids and electricity information collection systems, smart meters with built-in load switches are widely used in residential, industrial, and commercial electricity consumption scenarios to achieve remote power outages, power on / off switching, and electricity management and control. In actual operating environments, electricity meters are typically in a long-term load-bearing state, and the current circuit often uses manganese-copper alloy resistors and relay-type load switch structures. The circuit impedance and temperature rise directly affect the metering accuracy, safety, and overall lifespan of the meter.

[0003] In existing technologies, after receiving a tripping control command, electricity meters typically do not distinguish the phase state of AC voltage and current, but directly drive the load switch to perform a disconnection operation. When the tripping action occurs in a region with high AC current, it can easily generate large instantaneous current surges and arcing phenomena at the load switch contacts, leading to accelerated erosion and oxidation of the contact surfaces, which in turn increases contact resistance, circuit temperature rise, and a continuous increase in circuit impedance. This not only affects the long-term stable operation of the electricity meter, but may also shorten the service life of the load switch and key components of the current circuit, making it difficult to meet the increasingly stringent requirements of current power grid standards for the reliability and lifespan of electricity meters. Summary of the Invention

[0004] This application provides an adaptive processing method and system for reducing circuit impedance, which addresses the technical problems of large instantaneous current, severe heat generation, increased impedance, and contact damage caused by non-zero-crossing disconnection of built-in load switch energy meters during circuit breaker operation.

[0005] The first aspect of this application provides an adaptive processing method for reducing loop impedance, the method comprising: When the electricity meter is operating under load, upon receiving a trip control command, a complete trip process is triggered as an independent loop impedance suppression event. The periodic change signal of the AC voltage is acquired through a voltage sampling circuit connected to the live and neutral wires of the electricity meter, and the microcontroller determines the timing position of the voltage zero-crossing point within the current voltage cycle based on this signal. After the loop impedance suppression event is triggered, the timing position of the voltage zero-crossing point is used as the timing constraint for trip execution, and a trip delay control quantity matching the current voltage cycle is generated based on this timing position. According to the trip delay control quantity, the built-in load switch is controlled to perform a disconnection operation at the corresponding voltage zero-crossing point, ensuring that the load switch contact disconnection process occurs in a low-current range. Based on the control result, adaptive suppression processing of the current loop impedance is completed.

[0006] A second aspect of this application provides an adaptive processing system for reducing loop impedance, the system comprising: The system comprises the following modules: a trigger module, used to trigger a complete circuit breaker process as an independent loop impedance suppression event when the energy meter is operating under load and a circuit breaker control command is received; a data acquisition module, used to acquire the periodic change signal of AC voltage through a voltage sampling circuit connected to the live and neutral wires of the energy meter, and a microcontroller to determine the timing position of the voltage zero-crossing point within the current voltage cycle based on the periodic change signal; a control quantity determination module, used as the timing constraint condition of the voltage zero-crossing point after the loop impedance suppression event is triggered, and generating a circuit breaker delay control quantity matching the current voltage cycle based on the timing position; a disconnection execution module, used to control the built-in load switch to perform a disconnection operation at the corresponding voltage zero-crossing point according to the circuit breaker delay control quantity, so that the load switch contact disconnection process occurs in the low current range; and a suppression processing module, used to perform adaptive suppression processing of the current loop impedance based on the control results.

[0007] One or more technical solutions provided in this application have at least the following technical effects or advantages: This application, when the energy meter is operating under load and a trip control command is received, treats a complete trip process as an independent loop impedance suppression event. It acquires the periodic change signal of the AC voltage through a voltage sampling circuit connected to the live and neutral wires of the energy meter, and the microcontroller determines the timing position of the voltage zero-crossing point within the current voltage cycle based on this signal. After the loop impedance suppression event is triggered, the timing position of the voltage zero-crossing point is used as the timing constraint for trip execution, and a trip delay control quantity matching the current voltage cycle is generated based on this timing position. According to the trip delay control quantity, the built-in load switch is controlled to perform a disconnection operation at the corresponding voltage zero-crossing point, ensuring that the load switch contact disconnection process occurs in a low-current range. Based on the control result, adaptive suppression processing of the current loop impedance is completed. This invention solves the technical problems of large instantaneous current, severe heat generation, increased impedance, and contact damage caused by non-zero-crossing disconnection during the operation of the built-in load switch energy meter. It achieves the technical effect of low-current disconnection by adaptively detecting the voltage zero-crossing point and accurately controlling the timing of disconnection, effectively suppressing the increase of circuit impedance, reducing contact erosion and heat generation, and improving the service life of the load switch. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic flowchart of an adaptive processing method for reducing loop impedance provided in an embodiment of this application.

[0010] Figure 2 This is a schematic diagram of an adaptive processing system for reducing loop impedance provided in an embodiment of this application.

[0011] Explanation of reference numerals in the attached diagram: Trigger module 11, Data acquisition module 12, Control quantity determination module 13, Disconnection execution module 14, Suppression processing module 15. Detailed Implementation

[0012] This application provides an adaptive processing method and system for reducing circuit impedance, which addresses the technical problems of large instantaneous current, severe heat generation, increased impedance, and contact damage caused by non-zero-crossing disconnection during the tripping operation of built-in load switch energy meters. It achieves the technical effect of adaptively detecting the voltage zero-crossing point and accurately controlling the tripping timing to realize low-current disconnection, effectively suppressing the increase in circuit impedance, reducing contact erosion and heat generation, and improving the service life of the load switch.

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0014] It should be noted that any variation of the terms "comprising" and "having" is intended to cover non-exclusive inclusion, for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0015] Example 1, as Figure 1 As shown, this application provides an adaptive processing method for reducing loop impedance, the method comprising: Step S100: When the energy meter is in a loaded operating state, upon receiving a trip control command, a complete trip process is triggered as an independent loop impedance suppression event.

[0016] In this embodiment, when the electricity meter is operating normally and carrying electrical load, and receives a tripping control command via a local button, remote control, or management system, the system does not immediately execute the load switch disconnection operation. Instead, it defines the impending tripping action as an independent loop impedance suppression event. After this event is triggered, the internal control unit of the electricity meter enters a dedicated impedance suppression processing flow to uniformly manage and schedule this tripping operation. This loop impedance suppression event begins when the tripping command is received, spans the entire process including tripping timing calculation, delay control generation, and actual load switch disconnection, and automatically exits after the event ends. By triggering and processing each tripping process as an independent event, the system can perform targeted control of the tripping action based on the current load, voltage state, and loop conditions. This provides a complete and controllable execution environment for subsequent low-current tripping operations based on voltage zero-crossing points, ensuring the effectiveness and consistency of loop impedance suppression processing.

[0017] Step S200: Obtain the periodic change signal of AC voltage through the voltage sampling circuit connected to the live wire and neutral wire of the electricity meter, and the microcontroller determines the timing position of the voltage zero crossing point within the current voltage cycle based on the periodic change signal.

[0018] In this embodiment, a voltage sampling circuit is installed inside the energy meter. Its input terminals are connected to the live wire and neutral wire of the energy meter, respectively, to acquire AC voltage information between the two terminals in real time. The voltage sampling circuit performs current limiting, voltage division, and isolation processing on the AC voltage, coupling the signal that changes periodically with the AC voltage into a periodically changing signal in level / pulse form recognizable by the microcontroller. Subsequently, the microcontroller continuously reads this periodically changing signal at a preset sampling period and identifies the polarity switching or level inversion feature points of the signal within each AC voltage cycle. When a switching edge from the negative half-cycle to the positive half-cycle is detected, the edge moment is recorded as the zero-crossing neighborhood trigger moment of the current cycle, and a timing process is started. Afterwards, the time interval between two adjacent edge triggers is recorded within at least one complete cycle to obtain the cycle length of the current AC voltage, and the timing position of the voltage zero-crossing point relative to the start of the cycle within the current voltage cycle is calculated. Through the above steps of sampling, edge recognition, period measurement and delay compensation, the microcontroller can stably and in real time determine the zero-crossing point of the current voltage cycle under the field conditions of the power meter operating under load, providing a reliable time reference for subsequent power outages based on the zero-crossing point constraint.

[0019] Furthermore, in the method provided in the application embodiments, the microcontroller determines the timing position of the voltage zero-crossing point within the current voltage cycle based on the periodic change signal, which further includes: A current-limiting voltage divider branch, composed of multiple series resistors, couples the AC voltage between the neutral and live wire output terminals of the energy meter to a zero-crossing detection branch composed of diodes and optocouplers. This causes the optocoupler receiver to output a zero-crossing trigger level signal that changes with the polarity of the AC voltage. The zero-crossing trigger level signal is sent to the first pin of the microcontroller via the first resistor branch to form a zero-crossing detection level reference, and then sent to the second pin of the microcontroller via the second resistor branch to form a zero-crossing trigger signal for detecting level transitions. When the second pin detects a low-to-high edge transition of the zero-crossing trigger signal, and the corresponding edge transition satisfies the validity determination condition based on the zero-crossing detection level reference, it is determined that the zero-crossing neighborhood of the current AC voltage cycle has been entered, and the timing process is started. After the loop impedance suppression event is triggered, within the zero-crossing neighborhood, the time interval between adjacent edge transitions within at least one AC voltage cycle is recorded, using the edge transition time as the timing start point. Based on the time interval, the timing position of the voltage zero-crossing point within the current voltage cycle is determined.

[0020] In this embodiment, inside the energy meter, the AC voltage between the live wire output terminal and the neutral wire is first processed by a current-limiting and voltage-dividing branch composed of multiple resistors connected in series. This multi-stage resistor is used to limit the current and divide the amplitude of the AC voltage, ensuring that the voltage and current entering the subsequent detection circuit are within a safe range. The AC signal after current limiting and voltage division is coupled to a zero-crossing detection branch composed of diodes and optocouplers. The diodes are used to limit the current direction and suppress reverse voltage. The light-emitting terminal of the optocoupler alternates between conducting and cutting off states during the alternation of the positive and negative half-cycles of the AC voltage, causing the optocoupler receiver to output corresponding high and low level signals. Thus, the level signal output by the optocoupler receiver periodically flips with the change of AC voltage polarity, forming a clear level jump characteristic near the zero crossing of the AC voltage, thereby constituting a zero-crossing trigger level signal.

[0021] Subsequently, the zero-crossing trigger level signal is isolated by a resistor and then split into two paths, which are input to the microcontroller. The first path is sent to the first pin of the microcontroller via the first resistor branch, and is used as a zero-crossing detection level reference signal. This signal is used to characterize the current half-cycle state of the AC voltage and the signal stability. The second path is sent to the second pin of the microcontroller via the second resistor branch, and is used as a zero-crossing trigger signal for detecting level transitions. This pin is configured to edge-triggered or timed sampling detection mode to capture the moment of level change near the zero crossing.

[0022] Subsequently, during program execution, the microcontroller continuously monitors the input state of the second pin. When a zero-crossing trigger signal transitions from low to high, it immediately reads the zero-crossing detection level reference signal corresponding to the first pin and determines whether the transition is within the valid operating range. This determination condition includes at least the level amplitude being within the legal range, the transition duration meeting the minimum pulse width requirement, and the logical relationship between the reference level and the trigger level conforming to the preset zero-crossing criterion. When all the above conditions are met simultaneously, the microcontroller determines that the AC voltage corresponding to the level transition has entered the zero-crossing neighborhood of the current voltage cycle.

[0023] Upon confirming entry into the zero-crossing neighborhood, the microcontroller immediately starts its internal timer, using the moment of the level transition as the timing start point, and continues to monitor the next valid zero-crossing trigger edge during subsequent operation. The microcontroller records the time interval between two adjacent valid edge transitions within at least one complete AC voltage cycle, and can perform averaging or consistency checks on the time intervals of multiple consecutive cycles to eliminate errors caused by jitter and transient interference.

[0024] Under the condition that the loop impedance suppression event has been triggered, after detecting a valid zero-crossing trigger signal edge, the microcontroller records the moment of the edge occurrence as the timing start point. It then continues to monitor at least one subsequent valid zero-crossing trigger edge to obtain the time interval between two adjacent edges, thus determining the actual cycle length of the current AC voltage. The microcontroller combines the propagation delay caused by the switching on and off processes of the optocoupler, the phase shift time introduced by the resistor voltage divider and diode current limiting network, and the system processing delay generated by the microcontroller's own sampling, calculation, and control output to compensate and correct the timing start point. The time quantities corresponding to each delay are superimposed to form a comprehensive compensation quantity, which is then used to correct the original timing start point, thereby calculating the timing position of the actual zero-crossing point of the voltage within the current AC voltage cycle. This timing position serves as the time reference for subsequently generating the trip delay control quantity. After compensating for the inherent action delay of the load switch, it controls the built-in load switch to perform a disconnection operation in the low-current range near the voltage zero-crossing point, thereby achieving adaptive suppression of the current loop impedance.

[0025] Step S300: After the loop impedance suppression event is triggered, the timing position of the voltage zero crossing point is used as the timing constraint condition for the circuit breaker execution, and a circuit breaker delay control quantity matching the current voltage cycle is generated based on the timing position.

[0026] In this embodiment of the application, after the loop impedance suppression event is triggered, the microcontroller reads the determined timing position of the voltage zero crossing point and uses the timing position of the voltage zero crossing point as the timing constraint condition for the circuit breaker to be tripped, thereby limiting the time range of the built-in load switch disconnection action.

[0027] The microcontroller then calculates the actual cycle length of the current AC voltage based on the time interval between adjacent zero-crossing trigger edges and saves this result as the cycle calibration result. Subsequently, based on the timing position of the voltage zero-crossing point and the corresponding cycle calibration result, the microcontroller calculates the time deviation between the actual zero-crossing point and the ideal zero-crossing point, and constructs a zero-crossing phase offset compensation amount to characterize this time deviation.

[0028] After obtaining the zero-crossing phase offset compensation, the microcontroller superimposes it onto a preset tripping delay reference determined experimentally under the rated operating conditions of the energy meter, generating a tripping delay control quantity that matches the current AC voltage cycle. This tripping delay control quantity controls the microcontroller to output a load switch disconnection control signal when the appropriate delay is reached, ensuring that the contact disconnection action of the built-in load switch is synchronized with the voltage zero-crossing point in time. This guarantees that the tripping operation occurs in the low-current range, achieving adaptive suppression of the current loop impedance.

[0029] Furthermore, in the method provided in the application embodiment, generating a tripping delay control quantity that matches the current voltage cycle based on the timing position further includes: Based on the timing position and the corresponding period calibration result, a zero-crossing phase offset compensation amount is constructed; the zero-crossing phase offset compensation amount is superimposed on the preset circuit breaker delay reference to generate a circuit breaker delay control amount that matches the current AC voltage cycle.

[0030] Furthermore, the method provided in the application embodiments also includes: The preset tripping delay reference is determined based on the experimental calibration results of the electricity meter under rated operating conditions, and the preset tripping delay reference is 5ms-7ms.

[0031] In this embodiment of the application, after determining the timing position of the voltage zero crossing point, the microcontroller performs timing measurement on the time interval between two adjacent valid zero crossing trigger signals, and calculates the actual cycle length of the current AC voltage accordingly. The cycle length is stored as the cycle calibration result to reflect the actual change of the current AC voltage cycle.

[0032] The microcontroller then maps the timing position of the voltage zero-crossing point to the complete AC voltage cycle corresponding to the cycle calibration result. Through time difference calculation, it determines the time deviation between the actual voltage zero-crossing point and the theoretical zero-crossing position of the ideal AC voltage cycle, and defines this time deviation as the zero-crossing point phase offset compensation amount, which is used to describe the impact of zero-crossing detection, voltage fluctuation and system processing on the zero-crossing timing.

[0033] Subsequently, the microcontroller corrects the time characteristics in the trip control link. By recording the inherent time delay between the microcontroller outputting the disconnection control signal and the actual separation of the built-in load switch contacts, a response lag compensation quantity is constructed to describe the response characteristics of the load switch. The response lag compensation quantity reflects the action lag caused by factors such as load switch drive, contact movement, and mechanical inertia.

[0034] Based on this, the microcontroller reads a preset tripping delay reference obtained through experimental calibration of the energy meter under rated operating conditions. The preset tripping delay reference is 5ms-7ms, used to characterize the basic delay time required for the load switch to complete the disconnection action. The microcontroller adds the zero-crossing phase offset compensation and response lag compensation to the preset tripping delay reference to compensate and correct the tripping execution time, thereby generating a tripping delay control quantity that matches the current AC voltage cycle. The tripping delay control quantity is then used to control the built-in load switch to perform the disconnection operation at the corresponding voltage zero-crossing point, ensuring that the contact disconnection process stably occurs in the low current range, achieving adaptive suppression of the current loop impedance.

[0035] Furthermore, in the method provided in the application embodiments, generating a tripping delay control quantity that matches the current AC voltage cycle further includes: Record the inherent time delay between the microcontroller outputting the disconnection control signal and the actual separation of the built-in load switch contacts, and construct a response hysteresis compensation amount; perform compensation and correction on the trip delay control amount based on the response hysteresis compensation amount, and use the compensation and correction result to control the built-in load switch to perform a disconnection operation at the corresponding voltage zero crossing point.

[0036] In this embodiment, the microcontroller, while outputting the disconnection control signal, timestamps the output moment of the disconnection control signal and determines the corresponding moment when the built-in load switch contacts actually separate by monitoring the current change in the load switch circuit. By calculating the time difference between the control signal output moment and the actual contact separation moment, the inherent time delay between the microcontroller outputting the disconnection control signal and the actual separation of the built-in load switch contacts is recorded. This inherent time delay record is used as a time parameter to characterize the load switch's response lag and is determined as a response lag compensation amount to reflect the inherent action lag characteristics of the load switch from receiving the disconnection control signal to the actual separation of the contacts.

[0037] After obtaining the response lag compensation, the target disconnection time corresponding to the timing position of the voltage zero-crossing point is used as the time reference. This target disconnection time is set as the expected time point when the built-in load switch contacts need to complete actual separation. The response lag compensation is then introduced into the tripping timing calculation process. By moving the target disconnection time backward by one response lag compensation, the control trigger time for the microcontroller to output the disconnection control signal is determined. Then, the moment the tripping control command is received is used as the timing start point. The time difference between the control trigger time and the timing start point is calculated, and this time difference is determined as the compensated and corrected tripping delay control quantity.

[0038] Timing control is performed based on the compensated and corrected trip delay control quantity. When the delay reaches the corresponding time, a disconnection control signal is output, so that the built-in load switch contacts complete the actual separation at the target disconnection time corresponding to the timing position of the voltage zero crossing point. This ensures that the load switch disconnection operation is aligned with the voltage zero crossing point in time, guaranteeing that the contact disconnection process occurs in the low current range and achieving adaptive suppression of the current loop impedance.

[0039] Step S400: According to the aforementioned circuit breaker delay control quantity, control the built-in load switch to perform a disconnection operation at the corresponding voltage zero-crossing point, so that the load switch contact disconnection process occurs in the low current range.

[0040] In this embodiment, the microcontroller uses the moment of receiving the trip control command as the timing start point to count the trip delay control quantity. When the count reaches the time point corresponding to the trip delay control quantity, it outputs a disconnection control signal to drive the built-in load switch into the disconnection process. Since the trip delay control quantity is generated based on the timing position of the voltage zero-crossing point and compensated for the load switch response lag, the output time of the disconnection control signal corresponds to the voltage zero-crossing point in time. This ensures that the built-in load switch contacts align with the voltage zero-crossing point when they complete the actual separation, and that the contact disconnection process occurs in a low-current range where the AC current amplitude is close to zero.

[0041] Step S500: Based on the control results, complete the adaptive suppression processing of the current loop impedance.

[0042] In this embodiment, after controlling the disconnection sequence of the built-in load switch based on the aforementioned disconnection delay control quantity, the resulting control is that the built-in load switch contacts complete the actual disconnection in the low-current range corresponding to the voltage zero-crossing point. This control result reflects whether the disconnection operation is executed according to the predetermined timing constraints and the actual current conditions at the moment of disconnection. Based on this control result, by continuously ensuring that the load switch contacts disconnect in the low-current range, the arc energy and local heating at the moment of disconnection are reduced, the contact material ablation and thermal stress in the manganese-copper current loop are mitigated, and the increase in contact resistance and loop impedance caused by repeated high-current disconnection are suppressed. By repeatedly constraining the disconnection behavior according to the above control result during operation, the current loop impedance is kept at a low and stable level during use, thereby achieving adaptive suppression of the current loop impedance.

[0043] Based on the above adaptive circuit breaker control, in order to verify the effectiveness of the adaptive suppression method for reducing circuit impedance in actual operation, a comparative test was conducted on an energy meter that detects the AC voltage zero-crossing point in real time and dynamically adjusts the timing of circuit breaker execution during the circuit breaker process, and an energy meter that directly executes the circuit breaker operation without zero-crossing point detection and timing adjustment.

[0044] Under the same experimental conditions, a resistive load with a rated voltage of 220V and a load current of 10A was selected to keep the energy meter in a continuous load-bearing state, and to periodically trigger a trip command during operation. In the adaptive suppression process, the trip execution time is determined in real time based on the zero-crossing timing position detected in each AC voltage cycle, and timing compensation adjustment is performed in combination with the cycle measurement results and device response characteristics; while in the comparison method, the load switch performs a disconnection operation immediately after receiving the trip command, without detecting or correcting the AC voltage phase state.

[0045] Test results show that, without zero-point detection and timing adjustment, the instantaneous current value of the load switch contacts during multiple tripping operations is concentrated in the range of 6.5A to 8.8A. Some tripping actions occur in the range where the AC current is close to the peak value, and continuous visible arcs are formed at the contacts, with the duration of a single arc typically ranging from 1.3ms to 1.8ms. With the continuous accumulation of tripping operations, obvious ablation and oxidation phenomena gradually appear on the contact surface. After 5000 consecutive tripping operations, the circuit contact resistance increases from the initial measured value of approximately 0.35mΩ to the range of 0.46mΩ to 0.49mΩ, and the stable operating temperature of the conductor near the contacts increases from approximately 32℃ to the range of 45℃ to 48℃, indicating a significant trend of circuit impedance deterioration.

[0046] In contrast, when the AC voltage zero-crossing point is detected in real time during the tripping process and the tripping execution time is dynamically compensated and adjusted, the actual separation time of the load switch contacts can be stably aligned to the low current range according to changes in operating conditions. During the test, the current value at the moment of disconnection remained within the range of 0.6A to 0.9A for a long time, and only a brief and discontinuous weak arc was generated at the contact, with the duration of a single arc controlled between 0.1ms and 0.18ms. After 5000 tripping operations were completed continuously under the same load conditions, no obvious ablation was observed on the contact surface, and its circuit contact resistance only changed from the initial measured value of about 0.35mΩ to the range of 0.36mΩ to 0.38mΩ. The stable operating temperature of the conductor near the contact was maintained between 33℃ and 35℃, and the circuit impedance remained relatively stable.

[0047] The comparison results from the above operation process show that by continuously detecting the zero-crossing point of AC voltage and dynamically compensating and adjusting the timing of the disconnection during the disconnection process, the load switch can complete the disconnection operation under low current conditions under different operating states. This reduces the current surge and arc energy at the moment of disconnection as the number of disconnections accumulates, slows down contact erosion and thermal stress accumulation, suppresses the continuous rise of circuit contact resistance, and achieves adaptive suppression of current circuit impedance.

[0048] Furthermore, the method provided in the application embodiments also includes: Before determining the timing position of the voltage zero-crossing point within the current voltage cycle, based on the zero-crossing trigger signals acquired in at least two consecutive AC voltage cycles, the consistency of the time deviation between adjacent zero-crossing trigger times is determined. When the time deviation meets the preset stable threshold range, the corresponding voltage zero-crossing point is taken as the reference time for effective circuit breaker tripping.

[0049] In this embodiment, before determining the timing position of the voltage zero-crossing point within the current voltage cycle, the microcontroller uses a continuous periodic sampling method to collect the zero-crossing trigger signal output by the zero-crossing detection circuit within at least two consecutive AC voltage cycles, and timestamps the edges of the zero-crossing trigger signal appearing in each AC voltage cycle to obtain the corresponding zero-crossing trigger time. The zero-crossing trigger signal is a level transition signal formed near the voltage polarity switch after the AC voltage undergoes current limiting, voltage division, and isolation detection. The zero-crossing trigger time is used to characterize the time position of the AC voltage entering the zero-crossing neighborhood.

[0050] After acquiring the zero-crossing trigger moment, the microcontroller uses a time difference calculation method to perform a one-to-one time difference calculation on the zero-crossing trigger moments acquired in two adjacent consecutive AC voltage cycles, obtaining the time deviation between adjacent zero-crossing trigger moments. This time deviation is used to describe the degree of change in the zero-crossing trigger moment within a continuous cycle, reflecting the consistency characteristics of the zero-crossing detection results across different AC voltage cycles from a time perspective.

[0051] After obtaining the time deviation, a threshold discrimination method is used to compare the time deviation with a pre-set stable threshold range. The stable threshold range is used to limit the allowable jitter interval of the zero-crossing trigger moment, so as to eliminate abnormal triggering caused by power grid transient disturbances, noise interference, or detection edge jitter. When the time deviation falls within the stable threshold range, it is determined that the zero-crossing trigger signal in the corresponding continuous AC voltage cycle has time consistency and meets the stability requirements.

[0052] Under the condition that the consistency judgment is established, the voltage zero-crossing point corresponding to the zero-crossing trigger time that meets the stable threshold range condition is determined as the reference time for effective circuit breaker. In the subsequent calculation of the voltage zero-crossing point timing position and the generation of the circuit breaker delay control quantity, the reference time for effective circuit breaker is used as the time base for calculation, thereby avoiding the impact of unstable zero-crossing triggers on the circuit breaker timing control and improving the reliability and accuracy of voltage zero-crossing point identification and circuit breaker execution timing.

[0053] Furthermore, the method provided in the application embodiments also includes: After the built-in load switch is disconnected, the current change monitoring data before and after the disconnection is used to confirm whether the disconnection operation occurred in the low current range. Based on the confirmation results, a validity flag for the loop impedance suppression event is established, and the validity flag is recorded.

[0054] In this embodiment, after the built-in load switch is disconnected, the microcontroller continuously samples the current before and after the disconnection. The sampling object is the instantaneous current value in the current loop of the electricity meter, and corresponding current change monitoring data is acquired before and after the disconnection action to reflect the change of load current during the disconnection process. By analyzing the current change monitoring data, the moment when the current changes significantly from a stable load state to a near-zero state is determined, and this moment is used as the determination moment when the load switch contacts complete the actual separation.

[0055] After determining the actual contact separation time, the current amplitude corresponding to that time is extracted as the disconnection current amplitude. This disconnection current amplitude is then compared with a pre-set low current range threshold to determine whether the current is within the low current range when the tripping operation occurs. If the disconnection current amplitude falls within the low current range threshold, the tripping operation is confirmed to have occurred within the low current range. If the disconnection current amplitude exceeds the low current range threshold, the tripping operation is confirmed not to have occurred within the low current range.

[0056] Based on the above confirmation results, a validity identifier for loop impedance suppression events is established. Loop impedance suppression events that are confirmed to have occurred in the low current range are marked as valid events, while loop impedance suppression events that do not occur in the low current range are marked as invalid events. The corresponding validity identifiers are recorded together with the current loop control information.

[0057] Furthermore, the method provided in the application embodiments also includes: After packaging the control results and confirmation results into a time-series mapping, a joint encrypted dataset is constructed. The joint encrypted dataset is then distributed and encrypted for storage, and an adaptive processing encrypted record is constructed.

[0058] In this embodiment, the control result and confirmation result are first time-stamped according to the order of occurrence of loop impedance suppression events, and then associated with the corresponding tripping events to form a time-series mapping relationship containing event number, control execution time, and confirmation judgment conclusion. After establishing the time correspondence, data contents with the same time-series mapping relationship are combined to form structured data units, thereby completing the time-series mapping and packaging of control results and confirmation results.

[0059] After completing the timing mapping and packaging, the structured data units are encrypted. The control results and confirmation results are treated as a whole to generate a joint encrypted dataset, ensuring the integrity and immutability of the data content during storage. Subsequently, the joint encrypted dataset is written into multiple independent storage units for distributed storage according to preset storage rules, so that each encrypted data corresponds to the same loop impedance suppression event but is stored in different storage locations.

[0060] By performing distributed encrypted storage on the joint encrypted dataset, the control execution status and confirmation judgment results of a single loop impedance suppression event are stored in an encrypted and distributed manner for a long time, forming a corresponding adaptive processing encrypted record, thereby realizing the secure recording and subsequent traceability of the loop impedance adaptive processing process.

[0061] Furthermore, the method provided in the application embodiments also includes: If a zero-crossing trigger signal that meets the validity determination conditions is not obtained within the preset detection time window, the built-in load switch is controlled to perform a disconnection operation after a preset safety delay.

[0062] In this embodiment of the application, after receiving the power-off control command, the microcontroller starts zero-crossing trigger signal monitoring and simultaneously opens a preset detection time window to limit the detection duration. Within the preset detection time window, the zero-crossing trigger signal output by the zero-crossing detection circuit is continuously collected and judged to determine whether there is a zero-crossing trigger signal that meets the validity judgment condition.

[0063] If no zero-crossing trigger signal that meets the validity determination condition is detected at the end of the preset detection time window, it is determined that an effective zero-crossing point that can be used for circuit breaker timing control cannot be obtained under the current AC voltage state, and the circuit breaker delay calculation process based on the zero-crossing point is terminated.

[0064] After the above determination is made, the microcontroller selects a pre-set safety delay as the alternative time parameter for the circuit breaker execution, and uses the moment the circuit breaker control command is received as the starting point for timing the pre-set safety delay. When the timing reaches the time point corresponding to the pre-set safety delay, the microcontroller outputs a disconnection control signal to control the built-in load switch to perform a disconnection operation, thereby ensuring reliable disconnection of the load switch according to the preset safety strategy even without a valid zero-crossing trigger signal.

[0065] In summary, the embodiments of this application have at least the following technical effects: This application, when the energy meter is operating under load and a trip control command is received, treats a complete trip process as an independent loop impedance suppression event. It acquires the periodic change signal of the AC voltage through a voltage sampling circuit connected to the live and neutral wires of the energy meter, and the microcontroller determines the timing position of the voltage zero-crossing point within the current voltage cycle based on this signal. After the loop impedance suppression event is triggered, the timing position of the voltage zero-crossing point is used as the timing constraint for trip execution, and a trip delay control quantity matching the current voltage cycle is generated based on this timing position. According to the trip delay control quantity, the built-in load switch is controlled to perform a disconnection operation at the corresponding voltage zero-crossing point, ensuring that the load switch contact disconnection process occurs in a low-current range. Based on the control result, adaptive suppression processing of the current loop impedance is completed. This invention solves the technical problems of large instantaneous current, severe heat generation, increased impedance, and contact damage caused by non-zero-crossing disconnection during the operation of the built-in load switch energy meter. It achieves the technical effect of low-current disconnection by adaptively detecting the voltage zero-crossing point and accurately controlling the timing of disconnection, effectively suppressing the increase of circuit impedance, reducing contact erosion and heat generation, and improving the service life of the load switch.

[0066] Example 2, based on the same inventive concept as the adaptive processing method for reducing loop impedance in the foregoing examples, such as... Figure 2 As shown, this application provides an adaptive processing system for reducing loop impedance. The system and method embodiments in this application are based on the same inventive concept. The system includes: Triggering module 11 is used to trigger a complete circuit breaker process as an independent loop impedance suppression event when the power meter is in a loaded operating state and receives a circuit breaker control command; data acquisition module 12 is used to acquire the periodic change signal of AC voltage through a voltage sampling circuit connected to the live and neutral wires of the power meter, and the microcontroller determines the timing position of the voltage zero-crossing point within the current voltage cycle based on the periodic change signal; control quantity determination module 13 is used to use the timing position of the voltage zero-crossing point as the timing constraint condition for circuit breaker execution after the loop impedance suppression event is triggered, and generate a circuit breaker delay control quantity matching the current voltage cycle based on the timing position; disconnection execution module 14 is used to control the built-in load switch to perform a disconnection operation at the corresponding voltage zero-crossing point according to the circuit breaker delay control quantity, so that the load switch contact disconnection process occurs in the low current range; suppression processing module 15 is used to complete the adaptive suppression processing of current loop impedance based on the control result.

[0067] Furthermore, the system is also used to implement the following functions: A current-limiting voltage divider branch, composed of multiple series resistors, couples the AC voltage between the neutral and live wire output terminals of the energy meter to a zero-crossing detection branch composed of diodes and optocouplers. This causes the optocoupler receiver to output a zero-crossing trigger level signal that changes with the polarity of the AC voltage. The zero-crossing trigger level signal is sent to the first pin of the microcontroller via the first resistor branch to form a zero-crossing detection level reference, and then sent to the second pin of the microcontroller via the second resistor branch to form a zero-crossing trigger signal for detecting level transitions. When the second pin detects a low-to-high edge transition of the zero-crossing trigger signal, and the corresponding edge transition satisfies the validity determination condition based on the zero-crossing detection level reference, it is determined that the zero-crossing neighborhood of the current AC voltage cycle has been entered, and the timing process is started. After the loop impedance suppression event is triggered, within the zero-crossing neighborhood, the time interval between adjacent edge transitions within at least one AC voltage cycle is recorded, using the edge transition time as the timing start point. Based on the time interval, the timing position of the voltage zero-crossing point within the current voltage cycle is determined.

[0068] Furthermore, the system is also used to implement the following functions: Based on the timing position and the corresponding period calibration result, a zero-crossing phase offset compensation amount is constructed; the zero-crossing phase offset compensation amount is superimposed on the preset circuit breaker delay reference to generate a circuit breaker delay control amount that matches the current AC voltage cycle.

[0069] Furthermore, the system is also used to implement the following functions: The preset tripping delay reference is determined based on the experimental calibration results of the electricity meter under rated operating conditions, and the preset tripping delay reference is 5ms-7ms.

[0070] Furthermore, the system is also used to implement the following functions: Before determining the timing position of the voltage zero-crossing point within the current voltage cycle, based on the zero-crossing trigger signals acquired in at least two consecutive AC voltage cycles, the consistency of the time deviation between adjacent zero-crossing trigger times is determined. When the time deviation meets the preset stable threshold range, the corresponding voltage zero-crossing point is taken as the reference time for effective circuit breaker tripping.

[0071] Furthermore, the system is also used to implement the following functions: After the built-in load switch is disconnected, the current change monitoring data before and after the disconnection is used to confirm whether the disconnection operation occurred in the low current range. Based on the confirmation results, a validity flag for the loop impedance suppression event is established, and the validity flag is recorded.

[0072] Furthermore, the system is also used to implement the following functions: After packaging the control results and confirmation results into a time-series mapping, a joint encrypted dataset is constructed. The joint encrypted dataset is then distributed and encrypted for storage, and an adaptive processing encrypted record is constructed.

[0073] Furthermore, the system is also used to implement the following functions: Record the inherent time delay between the microcontroller outputting the disconnection control signal and the actual separation of the built-in load switch contacts, and construct a response hysteresis compensation amount; perform compensation and correction on the trip delay control amount based on the response hysteresis compensation amount, and use the compensation and correction result to control the built-in load switch to perform a disconnection operation at the corresponding voltage zero crossing point.

[0074] Furthermore, the system is also used to implement the following functions: If a zero-crossing trigger signal that meets the validity determination conditions is not obtained within the preset detection time window, the built-in load switch is controlled to perform a disconnection operation after a preset safety delay.

[0075] It should be noted that the order of the embodiments described above is for descriptive purposes only and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An adaptive processing method for reducing loop impedance, characterized by, The method includes: When the electricity meter is operating under load, when a trip control command is received, a complete trip process will be triggered as an independent loop impedance suppression event. The periodic change signal of AC voltage is obtained by a voltage sampling circuit connected to the live wire and neutral wire of the electricity meter, and the microcontroller determines the timing position of the voltage zero crossing point within the current voltage cycle based on the periodic change signal. After the loop impedance suppression event is triggered, the timing position of the voltage zero crossing point is used as the timing constraint condition for the circuit breaker execution, and a circuit breaker delay control quantity matching the current voltage cycle is generated based on the timing position. According to the aforementioned circuit breaker delay control amount, the built-in load switch is controlled to perform a disconnection operation at the corresponding voltage zero crossing point, so that the load switch contact disconnection process occurs in the low current range. The adaptive suppression of the current loop impedance is completed based on the control results.

2. The adaptive processing method of reducing return path impedance as claimed in claim 1, wherein, The microcontroller determines the timing position of the voltage zero-crossing point within the current voltage cycle based on the periodic change signal, including: The AC voltage between the neutral and live wire output terminals of the energy meter is coupled to the zero-crossing detection branch composed of diodes and optocouplers through a current-limiting and voltage-dividing branch consisting of multiple resistors connected in series. This allows the optocoupler receiver to output a zero-crossing trigger level signal that changes with the polarity of the AC voltage. The zero-crossing trigger level signal is sent to the first pin of the microcontroller via the first resistor branch to form a zero-crossing detection level reference, and then sent to the second pin of the microcontroller via the second resistor branch to form a zero-crossing trigger signal for detecting level transitions. When the zero-crossing trigger signal is detected by the second pin to switch from low to high edge, and the corresponding edge switch satisfies the validity determination condition based on the zero-crossing detection level reference, it is determined that the current AC voltage cycle has entered the zero-crossing neighborhood, and the timing process is started. After the loop impedance suppression event is triggered, within the zero-crossing neighborhood, the time interval between adjacent edge switchings within at least one AC voltage cycle is recorded, with the edge switching time as the timing start point, and the timing position of the voltage zero crossing point within the current voltage cycle is determined based on the time interval.

3. The adaptive processing method of reducing return path impedance according to claim 2, wherein, Based on the timing position, a trip delay control quantity matching the current voltage cycle is generated, including: Based on the timing position and the corresponding period calibration result, a zero-crossing phase offset compensation amount is constructed. The zero-crossing phase offset compensation is superimposed on the preset circuit breaker delay reference to generate a circuit breaker delay control quantity that matches the current AC voltage cycle.

4. The adaptive processing method of reducing return path impedance according to claim 3, wherein, The preset tripping delay reference is determined based on the experimental calibration results of the electricity meter under rated operating conditions, and the preset tripping delay reference is 5ms-7ms.

5. The adaptive processing method for reducing loop impedance as described in claim 2, characterized in that, Before determining the timing position of the voltage zero-crossing point within the current voltage cycle, based on the zero-crossing trigger signals acquired in at least two consecutive AC voltage cycles, the consistency of the time deviation between adjacent zero-crossing trigger times is determined. When the time deviation meets the preset stable threshold range, the corresponding voltage zero-crossing point is taken as the reference time for effective circuit breaker tripping.

6. The adaptive processing method for reducing loop impedance as described in claim 1, characterized in that, After the built-in load switch is disconnected, the current change monitoring data before and after the disconnection is used to confirm whether the disconnection operation occurred in the low current range. Based on the confirmation results, a validity identifier for the loop impedance suppression event is established, and the validity identifier is recorded.

7. The adaptive processing method for reducing loop impedance as described in claim 6, characterized in that, After packaging the control results and confirmation results into a time-series mapping, a joint encrypted dataset is constructed. The joint encrypted dataset is then distributed and encrypted for storage, and an adaptive processing encrypted record is constructed.

8. The adaptive processing method for reducing loop impedance as described in claim 3, characterized in that, Generate a trip delay control quantity that matches the current AC voltage cycle, including: Record the inherent time delay between the microcontroller outputting the disconnection control signal and the actual separation of the built-in load switch contacts, and construct the response hysteresis compensation amount. The circuit breaker delay control quantity is compensated and corrected based on the response hysteresis compensation amount, and the built-in load switch is controlled to perform a disconnection operation at the corresponding voltage zero crossing point using the compensation and correction result.

9. The adaptive processing method for reducing loop impedance as described in claim 1, characterized in that, If a zero-crossing trigger signal that meets the validity determination conditions is not obtained within the preset detection time window, the built-in load switch is controlled to perform a disconnection operation after a preset safety delay.

10. An adaptive processing system for reducing loop impedance, characterized in that, The system is used to perform an adaptive processing method for reducing loop impedance as described in any one of claims 1-9, the system comprising: The triggering module is used to trigger a complete circuit breaker process as an independent loop impedance suppression event when the power meter is in a loaded operating state and receives a circuit breaker control command. The data acquisition module is used to acquire the periodic change signal of AC voltage through the voltage sampling circuit connected to the live wire and neutral wire of the electricity meter, and the microcontroller determines the timing position of the voltage zero crossing point within the current voltage cycle based on the periodic change signal. The control quantity determination module is used to take the timing position of the voltage zero crossing point as the timing constraint condition for the circuit breaker execution after the circuit impedance suppression event is triggered, and generate a circuit breaker delay control quantity that matches the current voltage cycle based on the timing position. The disconnection execution module is used to control the built-in load switch to perform a disconnection operation at the corresponding voltage zero-crossing point according to the circuit breaker delay control amount, so that the load switch contact disconnection process occurs in the low current range. The suppression processing module is used to perform adaptive suppression processing of the current loop impedance based on the control results.

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