A smart grid-oriented electric energy metering information real-time transmission method

Abstract

The application discloses a kind of smart grid-oriented electric energy metering information real-time transmission method, belongs to electric energy meter transmission technical field, specifically includes: the measurement data abstract is converted into modulation unit sequence, the length ratio of injection segment and silence interval of each modulation unit is selected one of two preset ratios according to current bit value;The sending end applies driving pulse string in injection segment, and stops applying in silence interval;After receiving end detects injection segment start-stop time, it is calculated quotient value by pair to form ratio sequence, the start point of data load section is positioned by sliding window matching synchronous ratio mode, and quotient value is adjacent domain discrimination and reorganization measurement data abstract.The application realizes not depending on power frequency voltage zero-crossing point absolute time reference, and bit information is carried in the self-reference ratio of length in modulation unit.

Description

Technical Field

[0001] This invention relates to the field of electricity meter transmission technology, and specifically to a method for real-time transmission of electricity meter metering information for smart grids. Background Technology

[0002] As smart grid construction continues to extend to the low-voltage distribution and consumption ends, real-time collection of electricity metering information has become a fundamental aspect of distribution automation and user-side energy management. In centralized deployment scenarios such as industrial and commercial metering circuits, multi-tenant distribution boxes, and equipment zones in medical facilities, multiple electricity meters are often densely installed in the same metering box or adjacent locations. It is necessary to periodically upload summary metering data, such as accumulated electricity consumption, instantaneous power, and power quality indicators, to a local concentrator or building energy management platform. Existing transmission methods mainly rely on dedicated communication cables, short-range wireless modules, or narrowband power line carriers. However, in situations involving renovation of existing buildings, environments with strong electromagnetic interference, or where additional communication cables cannot be laid, these methods face multiple constraints, including construction limitations, signal attenuation, and spectrum control. Therefore, utilizing the existing electrical connection circuits of electricity meters to achieve non-intrusive transmission of metering information has become a technological exploration direction in recent years.

[0003] Existing research has proposed a power frequency communication technology scheme that utilizes instantaneous current pulses near the zero-crossing point of the power frequency voltage for information modulation. This scheme connects a signal injection circuit consisting of a controllable switch and a capacitor branch in parallel at the power input terminal of the electricity meter. The capacitor is connected within a microsecond-level time window before and after the voltage zero-crossing point. Weak distorted pulses in the voltage or current waveform are detected at a centralized point on the low-voltage side of the distribution transformer to achieve uplink data transmission. This method exhibits good adaptability in low-voltage distribution networks because the signal can naturally pass through the distribution transformer without the need for additional relay equipment. To carry binary information, the transmitting end typically quantizes and distinguishes the delay time of the pulse deviating from the zero-crossing point, and the receiving end reconstructs the bit information based on the detected pulse arrival time.

[0004] However, the aforementioned power frequency communication method suffers from an over-reliance on the accuracy of power frequency voltage zero-crossing detection. When multiple energy meters inject pulses densely on the same bus, the superimposed instantaneous current distortion causes a dynamic shift in the zero-crossing position. The zero-crossing times detected by different energy meters are inconsistent, resulting in each meter injecting pulses within an incorrect time window, thus shaking the absolute time reference of the receiving end's decision bit value. Simultaneously, existing modulation methods encode bit values ​​as a fixed delay time relative to the zero-crossing point of the pulse. Under the superimposed influence of waveform zero-crossing jitter introduced by power frequency periodic expansion or harmonic distortion caused by changes in the load of the distribution circuit, a non-negligible deviation occurs between the actual value and the preset value of the delay time. Furthermore, the measurement noise at the receiving end regarding the pulse arrival time further compresses the distinction interval between the delay time windows corresponding to adjacent bit values, causing a rapid degradation in the reliability of signal identification when multiple meters are operating concurrently. Summary of the Invention

[0005] The purpose of this invention is to provide a method for real-time transmission of electricity metering information for smart grids, solving the following technical problems:

[0006] When multiple meters are connected in a dense manner using power frequency communication, the superposition of current pulses causes dynamic offset of the zero-crossing point, making the absolute time reference of each energy meter inaccurate. At the same time, load changes and harmonic distortion cause the pulse delay time to deviate from the preset value, and the decision interval for the receiver to distinguish adjacent bit values ​​is insufficient, resulting in degradation of signal identification reliability when multiple meters are connected concurrently.

[0007] The objective of this invention can be achieved through the following technical solutions: A method for real-time transmission of electricity metering information for smart grids includes the following steps: S1. Input the metering data reading command for multiple energy meters to be read in the target metering loop, and obtain the metering data summary to be transmitted for each energy meter; S2. Convert the measurement data summary into a modulation unit sequence. The ratio of the injection segment duration to the silence interval of each modulation unit is selected from one of two preset ratios based on the current bit value. S3. For a single energy meter, receive the time base pulse, determine the injection segment duration and the silence interval duration according to the ratio of the modulation unit, apply a fixed frequency drive pulse train within the injection segment duration, and stop applying it within the silence interval duration. S4. Continuously sample the received signal at the centralized signal acquisition point, detect the start and end times of the injection segment through the envelope threshold and calculate its duration, and obtain the silence interval duration from the time difference between adjacent injection segments. S5. Calculate the ratio of each pair of durations to obtain the ratio sequence, search for the synchronization ratio pattern, perform neighborhood discrimination on the matched ratios, output the bit value and reconstruct the metering data summary. S6. Establish an association pair between the electricity meter identifier and the recombined metering data summary, encapsulate all association pairs into a data message and attach a reception completion time marker, and transmit it to the electricity acquisition concentrator through the local communication interface.

[0008] As a further aspect of the present invention: in step S2, the process of converting the metrological data summary into a modulation unit sequence is as follows: Cyclic redundancy check (CRC) calculations are performed on the measurement data summary. The CRC bit string is concatenated to the end of the original bit sequence of the measurement data summary to form a protection bit string to be transmitted. The duration of the injection segment corresponding to the first preset ratio is pre-stored as the first injection duration value and the duration of the silence interval is pre-stored as the first silence duration value. The duration of the injection segment corresponding to the second preset ratio is pre-stored as the second injection duration value and the duration of the silence interval is pre-stored as the second silence duration value. The first injection duration value is greater than the second injection duration value, and the first silence duration value is less than the second silence duration value. A synchronization ratio pattern bit string consisting of six binary bits is pre-stored. Each bit of the synchronization ratio pattern bit string is sequentially mapped to a modulation unit. Binary '1' is mapped to the first preset ratio value, and binary '0' is mapped to the second preset ratio value, generating a synchronization ratio pattern segment consisting of six modulation units. Each bit of the protection bit string to be transmitted is converted into the preset ratio value of each modulation unit in the data payload segment according to the same rule. The synchronization ratio pattern segment is placed before the data payload segment to form a modulation unit sequence.

[0009] As a further aspect of the present invention: In step S3, the injection segment duration and the silence interval duration are determined based on the ratio of the modulation units. A fixed frequency driving pulse train is applied during the injection segment duration, and the application is stopped during the silence interval duration. The ratio decoding circuit reads the preset ratio type selected for the current modulation unit. When the preset ratio type is the first preset ratio, the first injection duration value is loaded into the injection duration counter, and the first silence duration value is loaded into the interval duration counter. When the preset ratio type is the second preset ratio, the second injection duration value is loaded into the injection duration counter, and the second silence duration value is loaded into the interval duration counter. The injection duration counter starts counting down from the start of the effective edge of the time base pulse. During the counting period, it outputs an enable level to the drive pulse generator. The drive pulse generator outputs a drive pulse train to the controllable switching element control terminal at a fixed repetition frequency. When the injection duration counter returns to zero, the enable level is deactivated. The interval duration counter starts counting down when the injection duration counter returns to zero. During the counting period, the enable level is continuously turned off. When the interval duration counter returns to zero, the current modulation unit ends and waits for the next effective edge of the time base pulse.

[0010] As a further aspect of the present invention: In step S4, the received signal is continuously sampled at the centralized signal acquisition point, the start and end times of the injection segment are detected by the envelope threshold and its duration is calculated, and the silence interval duration is obtained from the time difference between adjacent injection segments as follows: The signal components coupled to the signal receiving loop are subjected to bandpass filtering. The center frequency of the passband of the bandpass filter is aligned with the fundamental frequency of the driving pulse train. The filtered signal is continuously sampled to obtain the original sampled value sequence. The original sampled value sequence is squared and then a moving average is performed to obtain a smooth envelope sequence. Each envelope value in the smooth envelope sequence is compared with a preset sensing threshold. When the envelope value crosses from below the preset sensing threshold to above the preset sensing threshold, the corresponding sampling time is recorded as the start time of the injection segment. When the envelope value crosses from above the preset sensing threshold to below the preset sensing threshold, the corresponding sampling time is recorded as the end time of the injection segment. The end time of the same injection segment is subtracted from the start time to obtain the measured value of the duration of the injection segment. The start time of the current injection segment is subtracted from the end time of the previous injection segment to obtain the measured value of the duration of the silence interval.

[0011] As a further aspect of the present invention: In step S5, the process of calculating the ratio of each pair of durations to obtain a ratio sequence and searching for a synchronization ratio pattern is as follows: The measured values ​​of the injection segment duration and the silence interval duration of multiple consecutive modulation units are paired and their quotients are calculated. All quotients are arranged in the order of appearance of the modulation units to form a ratio sequence. Starting from the first quotient of the ratio sequence, six consecutive quotients are extracted as the current comparison window. The absolute values ​​of the differences between the six quotients in the current comparison window and the six target ratios of the synchronization ratio pattern template are calculated bit by bit and accumulated to obtain the cumulative deviation value. If the cumulative deviation value is less than the preset synchronization deviation tolerance value, the starting position of the current comparison window is marked as the synchronization pattern matching position, and the quotient value immediately following the synchronization pattern matching position is taken as the starting point of the data payload segment. If the cumulative deviation value is greater than or equal to the preset synchronization deviation tolerance value, the comparison window is moved one quotient position to the right and six quotients are extracted again for comparison. This process is repeated until all positions in the ratio sequence have been searched.

[0012] As a further aspect of the present invention: In step S5, the process of performing neighborhood discrimination on the matched ratio, outputting bit values, and reconstructing the measurement data summary is as follows: Each quotient value is sequentially extracted from the starting position of the data payload segment. The absolute value of the difference between the current quotient value and the reference constant corresponding to the first preset ratio and the reference constant corresponding to the second preset ratio is obtained to obtain the first deviation and the second deviation. If the first deviation is less than the second deviation, it is determined to be the first bit value. If the second deviation is less than the first deviation, it is determined to be the second bit value. If the first deviation is equal to the second deviation, the determination result of the previous quotient value is used. All bit values ​​are concatenated in order to obtain the transmission bit sequence. Cyclic redundancy check is performed on the transmission bit sequence. After the check passes, the check bit string is stripped to restore the measurement data summary.

[0013] As a further aspect of the present invention: In step S6, the process of establishing an association pair between the electricity meter identifier and the reconstructed metering data summary, encapsulating all association pairs into a data message and attaching a reception completion time marker, and transmitting it to the electricity acquisition concentrator through the local communication interface is as follows: Within the centralized signal acquisition point controller, a storage buffer block is statically allocated for each registered energy meter. The fixed starting address of the storage buffer block is mapped one-to-one with the energy meter identifier. After each metering data summary is reconstructed, the energy meter identifier is determined based on the matched synchronization ratio pattern. The metering data summary is written to the corresponding storage buffer block and the data ready flag is set. A periodic reporting timer is set. When the periodic reporting timer overflows, the data ready flags of each storage buffer block are queried in turn. The ready metering data summary, the corresponding energy meter identifier, and the timestamp of the periodic reporting timer overflow are concatenated into a single record, and the data ready flag of the corresponding storage buffer block is cleared. All records are sorted in ascending order by energy meter identifier, and after adding the total number of records and the cyclic redundancy check code, they are encapsulated into a data packet and sent to the energy acquisition concentrator through the universal asynchronous transceiver interface.

[0014] As a further aspect of the present invention: when the input metering data reading command involves multiple energy meters simultaneously, the method for distinguishing signals from different energy meters is as follows: In S1, a corresponding synchronization ratio mode bit string is pre-assigned to each energy meter. The number of different bits between the synchronization ratio mode bit strings of different energy meters exceeds a preset distinguishing lower limit. The length of the synchronization ratio mode bit string is uniformly six bits. In S2, each energy meter generates a corresponding synchronization ratio mode segment and data payload segment according to its assigned synchronization ratio mode bit string. The combined modulation unit sequence contains its own synchronization ratio mode. In S5, the ratio sequence is compared in parallel with all the stored synchronization ratio mode templates. Each synchronization ratio mode template independently performs sliding window comparison and records the cumulative deviation value and matching position. When the cumulative deviation value of any synchronization ratio mode template is less than the preset synchronization deviation tolerance value, the data payload segment after the matching position of the synchronization ratio mode template is used to restore the metering data summary of the corresponding energy meter. When multiple synchronization ratio mode templates are simultaneously less than the preset synchronization deviation tolerance value, the metering data summary of each energy meter is restored independently.

[0015] The beneficial effects of this invention are: This invention uses the ratio of the duration of the injection segment to the duration of the silent interval to carry bit information, replacing the dependence on the absolute delay time of the zero-crossing point of the power frequency voltage. This transforms the bit decision benchmark from an external power frequency phase reference to a self-reference of the time structure within the modulation unit, fundamentally eliminating the impact of dynamic zero-crossing offset caused by the superposition of multiple pulses on the inaccuracy of the injection timing. The modulation unit ratio encoding naturally resists waveform jitter introduced by power frequency periodic stretching and harmonic distortion at the time-domain envelope level. Within the same modulation unit, the injection segment and the silent interval are stretched or compressed in the same direction by the same channel disturbance, and their ratio remains relatively stable with load changes, thereby widening the decision interval for the receiver to distinguish between the two preset ratios. The receiver forms a ratio sequence by pairwise quotients of the measured values ​​of the injection segment duration and the silent interval duration. A sliding window matching is performed using a synchronization ratio pattern template to determine the synchronization position and complete neighborhood discrimination from the quotient sequence at once. Synchronization acquisition and data restoration share the same ratio dimension, avoiding the accumulation of timing deviations caused by the separation of synchronization and data paths in time-division multiplexing. Based on this, different synchronization ratio mode templates are assigned to different energy meters. After the modulation unit sequences sent by multiple energy meters are matched by parallel templates at the centralized signal acquisition point, the starting point of each data load segment is located according to the matching position of each template, so as to realize the concurrent separation and restoration of signals from multiple meters on the same bus. Attached Figure Description

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a flowchart illustrating the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1 As shown, this invention provides a method for real-time transmission of electricity metering information for smart grids, comprising the following steps: S1. Input the metering data reading command for multiple energy meters to be read in the target metering loop, and obtain the metering data summary to be transmitted for each energy meter; S2. Convert the measurement data summary into a modulation unit sequence. The ratio of the injection segment duration to the silence interval of each modulation unit is selected from one of two preset ratios based on the current bit value. S3. For a single energy meter, receive the time base pulse, determine the injection segment duration and the silence interval duration according to the ratio of the modulation unit, apply a fixed frequency drive pulse train within the injection segment duration, and stop applying it within the silence interval duration. S4. Continuously sample the received signal at the centralized signal acquisition point, detect the start and end times of the injection segment through the envelope threshold and calculate its duration, and obtain the silence interval duration from the time difference between adjacent injection segments. S5. Calculate the ratio of each pair of durations to obtain the ratio sequence, search for the synchronization ratio pattern, perform neighborhood discrimination on the matched ratios, output the bit value and reconstruct the metering data summary. S6. Establish an association pair between the electricity meter identifier and the recombined metering data summary, encapsulate all association pairs into a data message and attach a reception completion time marker, and transmit it to the electricity acquisition concentrator through the local communication interface.

[0020] In a preferred embodiment of the present invention, the process of converting the metrological data summary into a modulation unit sequence in step S2 is as follows: First, it is necessary to define a modulation unit. In this invention, a modulation unit is the basic transmission unit constituting an intermittent pulse train sequence. Each modulation unit consists of a time-closely connected injection segment and a silence interval. An injection segment refers to the time interval during which the energy meter continuously applies a drive pulse train to the controllable switching element in the signal injection circuit, causing the signal injection circuit to continuously couple signal components to the distribution circuit. The silence interval refers to the time interval immediately following the injection segment where the energy meter stops applying any drive to the controllable switching element, and the signal injection circuit is in a high-impedance, non-injection state. An injection segment and a silence interval constitute a complete modulation unit. The boundary of the modulation unit is defined by the start time of the injection segment and the end time of the silence interval.

[0021] The microcontroller inside the electricity meter reads the metering data summary to be transmitted from the metering chip. The metering data summary can be coded data of the accumulated active power, reactive power, instantaneous power, or power quality indicators within a single data acquisition cycle. The microcontroller performs a cyclic redundancy check (CRC) calculation on the original bit sequence of the metering data summary. The CRC calculation uses a well-known CRC-16 or CRC-32 generator polynomial, generating a fixed-length check bit string. The microcontroller directly appends the check bit string to the end of the original bit sequence of the metering data summary in a pre-defined order (most significant bit first, least significant bit first), forming the protection bit string to be transmitted. The total number of bits in the protection bit string is equal to the number of bits in the original bit sequence of the metering data summary plus the number of bits in the check bit string.

[0022] The microcontroller internally stores two preset ratios, each corresponding to one of two configuration combinations. The first preset ratio combination specifies that the duration of each injection segment is the first injection duration, and the duration of the silence interval is the first silence duration. The second preset ratio combination specifies that the duration of each injection segment is the second injection duration, and the duration of the silence interval is the second silence duration. The first injection duration is numerically greater than the second injection duration, and the first silence duration is numerically less than the second silence duration. For example, the first injection duration can be 6 time base pulse cycles, and the first silence duration can be 3 time base pulse cycles, resulting in a first preset ratio of 2:1. The second injection duration can be 3 time base pulse cycles, and the second silence duration can be 6 time base pulse cycles, resulting in a second preset ratio of 1:2. The ratio of the duration of the injection segment to the duration of the silence interval is determined by the current bit value to be transmitted. When the bit value to be transmitted is binary 1, the modulation unit is assigned a first preset ratio. When the bit value to be transmitted is binary 0, the modulation unit is assigned a second preset ratio.

[0023] The microcontroller also pre-stores a synchronization ratio mode bit string consisting of six binary bits. The purpose of this bit string is to provide a frame synchronization reference at the receiving end, enabling the centralized signal acquisition points to identify the starting boundary of the data payload segment from a continuous sequence of modulation units. Each bit of the synchronization ratio mode bit string corresponds sequentially to the first six modulation units in the sequence. A binary 1 maps to the first preset ratio, and a binary 0 maps to the second preset ratio. For example, if the synchronization ratio mode bit string is 101100, then the corresponding six modulation units will sequentially use the first preset ratio, the second preset ratio, the first preset ratio, the first preset ratio, the second preset ratio, and the second preset ratio. These six modulation units constitute the synchronization ratio mode segment.

[0024] The microcontroller places the synchronization ratio mode segment before the data payload segment, forming a complete modulation unit sequence. The preset ratio of each modulation unit in the data payload segment is determined by the corresponding bits of the protection bit string to be transmitted according to the same mapping rule. In the entire modulation unit sequence, the first six modulation units belong to the synchronization ratio mode segment, and the subsequent modulation units belong to the data payload segment. The number of modulation units in the data payload segment is equal to the total number of bits in the protection bit string to be transmitted.

[0025] During implementation, the microcontroller stores the entire modulation unit sequence in a table format in its internal transmit buffer. Each entry in the transmit buffer records all control parameters for a modulation unit, including the duration of the injection segment and the duration of the silence interval corresponding to that modulation unit. The transmit program reads the control parameters one by one in order and submits them to the ratio decoding circuit in S3 for execution.

[0026] In another preferred embodiment of the present invention, in step S3, the injection segment duration and the silence interval duration are determined based on the ratio of the modulation units. A fixed frequency driving pulse train is applied during the injection segment duration, and the application is stopped during the silence interval duration. The electricity meter incorporates an independent ratio decoding circuit. This circuit is implemented using a hardware logic gate array (GGBA) or a programmable logic unit (PLU) within a microcontroller, and is connected to the transmit buffer via a parallel data bus. At the start of each modulation unit, the ratio decoding circuit reads the preset ratio type identifier selected for that modulation unit from the transmit buffer. This preset ratio type identifier is a 1-bit binary signal; a high level indicates the first preset ratio, and a low level indicates the second.

[0027] The output of the ratio decoding circuit is connected to the load input of the injection duration counter and the interval duration counter. Both the injection duration counter and the interval duration counter are decrementing counters, each containing a load register storing the initial decrement value and a decrementing counting logic. When the preset ratio type identifier output by the ratio decoding circuit is the first preset ratio, the load register of the injection duration counter is written with the first injection duration value, and the load register of the interval duration counter is written with the first silence duration value. When the preset ratio type identifier is the second preset ratio, the load register of the injection duration counter is written with the second injection duration value, and the load register of the interval duration counter is written with the second silence duration value.

[0028] The time base pulse is generated by a high-stability crystal oscillator within the energy meter body via a frequency divider circuit. The center frequency of the high-stability crystal oscillator can be selected from integer multiples of the power frequency, such as 32768 Hz or 1 MHz. The frequency divider circuit divides the crystal oscillator frequency to a time base frequency that matches the time resolution of the modulation unit. The effective edge of the time base pulse refers to the rising edge of the time base pulse transitioning from a low level to a high level. The processing cycle of each modulation unit is triggered by the effective edge of the time base pulse.

[0029] When the effective edge of the time base pulse arrives, the injection duration counter loads the value in the load register into the decrement count register in parallel, and starts counting down from that value in steps of the time base pulse period. During the decrement count, the output of the injection duration counter maintains a high-level enable signal, which is directly connected to the enable input of the drive pulse generator. Upon receiving the enable level, the drive pulse generator internally generates a continuous train of drive pulses at a fixed repetition frequency. The fixed repetition frequency is determined by the oscillation circuit inside the drive pulse generator, and the oscillation frequency is set between several kilohertz and tens of kilohertz, so that a sufficient number of drive pulses can be accommodated within the injection segment to form a reliable envelope detection energy at the receiving end. The drive pulse train output by the drive pulse generator is applied to the control terminal of the controllable switching element via an isolated drive circuit. The controllable switching element uses a bidirectional thyristor or a solid-state relay. In its on state, it connects the capacitor branch in the signal injection circuit connected in parallel to the power input terminal of the energy meter to the AC power circuit. The instantaneous charging current of the capacitor branch forms a current pulse in the power distribution circuit. Because the drive pulse train continuously triggers the controllable switching element at a fixed repetition frequency, the signal injection circuit repeatedly injects a series of densely arranged current pulses into the power distribution circuit during the entire injection segment duration.

[0030] When the injection duration counter decrements to zero, its operating status output flips to a low level, deactivating the enable signal to the drive pulse generator. Simultaneously with the injection duration counter reaching zero, its carry output signal triggers the interval duration counter to start. The interval duration counter loads the silence interval duration value from the load register into the decrement count register and begins counting down from that value. During the decrementing period, the interval duration counter's operating status output remains low. This signal, through an AND gate, disables the enable input of the drive pulse generator, resulting in no pulse output from the drive pulse generator. The controllable switching elements remain off, and the signal injection circuit injects no signal component into the power distribution circuit during the entire silence interval. When the interval duration counter decrements to zero, the entire processing of this modulation unit ends. The ratio decoding circuit pointer moves to the next entry in the transmit buffer, and the ratio decoding circuit waits for the next valid edge of the time base pulse to start the processing of the next modulation unit.

[0031] In another preferred embodiment of the present invention, in step S4, the received signal is continuously sampled at the centralized signal acquisition point, the start and end times of the injection segment are detected by the envelope threshold and its duration is calculated, and the silence interval duration is obtained from the time difference between adjacent injection segments as follows: Centralized signal acquisition points are deployed at the low-voltage side outgoing terminals of distribution transformers or at centralized signal acquisition locations on the busbar. The core detection component of the centralized signal acquisition point is a signal receiving loop. This loop can utilize a current transformer connected to the busbar to couple the current pulse signal component injected by the energy meter from the busbar current. Alternatively, it can extract the voltage distortion component caused by the pulse through a high-pass filter circuit on the secondary side of the busbar voltage transformer. The raw signal components coupled by the signal receiving loop include discontinuous pulse trains injected by the energy meter, the fundamental component of the power frequency current or voltage, and various background noises in the distribution circuit.

[0032] The signal conditioning circuit within the centralized signal acquisition point first performs bandpass filtering on the signal components coupled to the signal receiving loop. The passband center frequency of the bandpass filter is set to match the fundamental frequency of the driving pulse train. The fundamental frequency of the driving pulse train refers to the center frequency of the main lobe of the pulse train output by the driving pulse generator in the spectrum, which is determined by the fixed repetition frequency of the driving pulse generator in S3. The passband width of the bandpass filter is selected to be 20% to 50% of the fundamental frequency, which allows most of the energy of the pulse train to pass through while effectively suppressing the power frequency fundamental wave and its low-order harmonics, as well as high-frequency noise above the pulse train frequency band.

[0033] The signal, after bandpass filtering, is fed into an analog-to-digital converter (ADC). The ADC continuously samples the signal at a preset sampling rate, which is 8 to 16 times the fundamental frequency of the driving pulse train, ensuring sufficient sampling points for subsequent envelope extraction within each driving pulse cycle. The original sampled value sequence output by the ADC consists of signed or unsigned integer values ​​arranged at equal intervals according to the sampling time, with each sampled value corresponding to one sampling time.

[0034] The signal processing logic performs square-law envelope detection on the original sampled value sequence. Specifically, square-law envelope detection involves squaring each sampled value in the original sequence, multiplying it by itself to obtain a sequence of squared values. During the squaring operation, the positive and negative signs of the original sampled values ​​are eliminated, and the energy contribution of all sampled values ​​is uniformly positive. A moving average is then applied to the squared values ​​of multiple adjacent sample points in the squared value sequence. The width of the moving average window is the ratio of the analog-to-digital converter's sampling rate to one cycle of the fundamental frequency of the driving pulse train. For example, when the sampling rate is 12 times the fundamental frequency, the moving average window width is 12 sample points. The moving average operation involves summing all squared values ​​within the window and dividing by the window width. The average value calculated by the sliding window at the current sampled point is used as the smoothed envelope value corresponding to that sampled point. The sliding window moves forward point by point in sequence, recalculating the average value after each move, and outputting a smoothed envelope sequence that corresponds one-to-one with the original sampled value sequence.

[0035] Each envelope value in the smooth envelope sequence reflects the energy strength of the pulse signal component in the signal receiving loop near the current moment. During the duration of the injection segment, the signal receiving loop is continuously coupled to a densely packed array of drive pulses, and the smooth envelope value remains at a high level. During the duration of the silence interval, the signal receiving loop receives no pulse signal input and only background noise, causing the smooth envelope value to drop back to a low level.

[0036] The signal processing logic compares each envelope value in the smooth envelope sequence sequentially with a preset sensing threshold. The preset sensing threshold is a pre-calibrated fixed threshold, with its value falling between the maximum value of the smooth envelope caused by background noise without injection and the minimum value of the smooth envelope caused by a single driving pulse. The calibration method can be to continuously sample and calculate the smooth envelope sequence without any energy meter injection signal, and then take 1.5 to 2 times the maximum value of the smooth envelope sequence as the preset sensing threshold.

[0037] When the envelope value at a point in the smooth envelope sequence is lower than a preset sensing threshold, while the envelope value at the next point is higher than the preset sensing threshold, an upward crossing is determined to have occurred. The signal processing logic records the sampling time corresponding to this crossing moment. The precise location of the crossing moment is calculated by linear interpolation of the sampling times of two consecutive sampling points below and above the threshold. The linear interpolation process is as follows: take the sampling time of the previous sampling point as time one, take the sampling time of the next sampling point as time two, subtract the envelope value of time one from the preset sensing threshold as difference one, and subtract the preset sensing threshold value from the envelope value of time two as difference two. The crossing moment is equal to time one plus the time difference between time one and time two multiplied by difference one, and then divided by the sum of difference one and difference two. This crossing moment is recorded as the start time of the injection segment.

[0038] When the envelope value at a point in the smooth envelope sequence is higher than a preset sensing threshold, while the envelope value at the next point is lower than the preset sensing threshold, a top-down crossing is determined to have occurred. The crossing time is calculated using the same linear interpolation method and is recorded as the end time of the injection segment.

[0039] The signal processing logic pairs detected adjacent start and end times. The pairing rule is that, in the detection order, the first end time appearing after a start time belongs to the same injection segment as that start time. Subtracting the start time from the successfully paired end time gives the measured duration of the injection segment. Subtracting the previously successfully paired end time from the currently successfully paired start time gives the measured duration of the silence interval of the previous modulation unit. For the first injection segment in the entire modulation unit sequence, the measured duration of its silence interval is not calculated, or the moment when the first crossover of the envelope value is detected is used as the global starting reference point.

[0040] The signal processing logic stores the measured duration values ​​of each injection segment and the measured duration value of the silence interval, obtained consecutively, into the detection buffer in chronological order of detection time. The detection buffer is a circular buffer; when the buffer write pointer reaches the end of the buffer, it automatically wraps back to the beginning address of the buffer, overwriting the earliest historical record. The capacity of the detection buffer is set to be sufficient to hold the duration measurement value pairs of all modulation units in the modulation unit sequence.

[0041] In another preferred embodiment of the present invention, in step S5, the process of calculating the ratio of each pair of durations to obtain a ratio sequence and searching for a synchronization ratio pattern is as follows: The signal processing logic within the centralized signal acquisition point sequentially reads the measured durations of injection segments and silence intervals from the detection buffer in chronological order. The detection buffer stores paired duration records, each pair consisting of a first member (member 1) and a second member (member 2). Member 1 is the measured duration of the injection segment, and member 2 is the measured duration of the silence interval immediately following the injection segment. The order in which the paired duration records are stored in the detection buffer is completely consistent with the order in which the modulation units arrive at the centralized signal acquisition point.

[0042] The signal processing logic starts from the first record in the detection buffer and retrieves the measured values ​​of the injection segment duration and the silence interval duration in pairs. For each pair of duration records, the signal processing logic performs a quotient calculation. The specific operation of the quotient calculation involves using the measured value of the injection segment duration as the dividend and the measured value of the silence interval duration as the divisor, and obtaining the ratio between the two through integer division or floating-point division. Due to the combined effects of signal attenuation, noise superposition, and quantization errors at the envelope detection threshold crossing time during channel transmission, the measured quotient results obtained for the same preset ratio in different modulation units will exhibit a discrete distribution around a central value. For example, for the first preset ratio with a nominal injection segment duration of 6 time base periods and a nominal silence interval duration of 3 time base periods, its theoretical ratio is 2.0, but the quotient measured at the receiver may fluctuate within the range of 1.8 to 2.2. For the second preset ratio with a nominal injection segment duration of 3 time base periods and a nominal silence interval duration of 6 time base periods, the theoretical ratio is 0.5, and the quotient obtained by actual measurement at the receiving end may fluctuate in the range of 0.4 to 0.6.

[0043] The signal processing logic sequentially writes the calculated quotients into a first-in, first-out shift register group according to the order in which the modulation units appear. The depth of this shift register group matches the total number of quotients that the receiver needs to buffer. The quotients stored in each memory cell of the shift register group form a ratio sequence. The first quotient in the ratio sequence corresponds to the first modulation unit received by the centralized signal acquisition point, the second quotient corresponds to the second modulation unit received, and so on.

[0044] Simultaneously with the formation of the ratio sequence, the signal processing logic initiates a synchronization search process. The purpose of the synchronization search process is to pinpoint the precise boundary position within the ratio sequence where the synchronization ratio pattern segment ends and the data payload segment is about to begin. The synchronization ratio pattern template is a set of six target ratios pre-stored within the centralized signal acquisition points. These six target ratios correspond bit-by-bit to the synchronization ratio pattern bit string defined in S2. Each bit of the synchronization ratio pattern bit string determines whether a target ratio belongs to the theoretical value of the first preset ratio or the theoretical value of the second preset ratio. For example, when the synchronization ratio pattern bit string is 101100, the corresponding six target ratios are, in order, the theoretical values ​​of the first preset ratio, the second preset ratio, the first preset ratio, the first preset ratio, the second preset ratio, and the second preset ratio.

[0045] The signal processing logic extracts six consecutive quotient values ​​from the first quotient value in the ratio sequence as the current comparison window. This window covers the first to sixth quotient values ​​in the ratio sequence. The signal processing logic calculates the absolute difference between the first quotient value in the current comparison window and the first target ratio of the synchronization ratio pattern template, obtaining the absolute difference for the first quotient. Then, it calculates the absolute difference between the second quotient value and the second target ratio of the synchronization ratio pattern template, obtaining the absolute difference for the second quotient, and so on, until all six quotients have been calculated. This bit-by-bit comparison process examines whether the overall change pattern of the six consecutive quotient values ​​in the current comparison window is similar in shape to the preset alternating high and low ratio pattern specified by the synchronization ratio pattern template. Because the synchronization ratio pattern template specifies a specific sequence pattern of high and low ratios, while the quotient values ​​in the comparison window are a series of measured values, simply comparing whether the quotient values ​​are equal is meaningless. Therefore, the accumulated absolute difference is used as a measure of pattern similarity. The signal processing logic sums the absolute values ​​of the differences between the six bits to obtain the cumulative deviation value.

[0046] The signal processing logic compares the cumulative deviation value with a preset synchronization deviation tolerance value. The preset synchronization deviation tolerance value is a pre-defined numerical threshold, set based on statistical analysis of the quotient fluctuation range caused by channel noise. For example, when the typical fluctuation range of the quotient corresponding to the first preset ratio is 2.0 ± 0.2, and the typical fluctuation range of the quotient corresponding to the second preset ratio is 0.5 ± 0.1, the cumulative deviation of the six modulation units within a complete synchronization mode segment is ideally close to zero, but under maximum fluctuation conditions, it may reach 6 times 0.2, or approximately 1.2. The preset synchronization deviation tolerance value can be between 1.5 and 2.0, which tolerates normal fluctuations without misclassifying asynchronous segments with different ratio modes as synchronous segments.

[0047] If the cumulative deviation is less than the preset synchronization deviation tolerance, the signal processing logic determines that the overall pattern of the six consecutive quotients in the current comparison window matches the synchronization ratio pattern template successfully. The signal processing logic records the index of the starting position of the current comparison window in the ratio sequence as the synchronization pattern matching position. The synchronization pattern matching position corresponds to the position of the first modulation unit in the synchronization ratio pattern segment within the ratio sequence. Since the synchronization ratio pattern segment is fixed at six modulation units, the starting position of the data payload segment is six quotients forward from the synchronization pattern matching position. The signal processing logic adds the quotient value in the ratio sequence pointed to by 6 to the synchronization pattern matching position as the first quotient of the data payload segment.

[0048] If the cumulative deviation value is greater than or equal to the preset synchronization deviation tolerance value, the signal processing logic determines that the current comparison window does not match the synchronization ratio pattern template. The signal processing logic moves the starting position of the comparison window one quotient value position to the end of the ratio sequence, that is, moves the comparison window from the original 1st to 6th quotient values ​​to the 2nd to 7th quotient values, and re-truncates 6 quotient values ​​to perform the same operation of subtracting each quotient, taking the absolute value, and accumulating. If there is still no match, the comparison window continues to move one position to the end, becoming the 3rd to 8th quotient values, and so on. The comparison window slides along the ratio sequence one position at a fixed pace of one quotient value at a time until the cumulative deviation value is less than the preset synchronization deviation tolerance value for the first time or the end of the comparison window exceeds the end of the ratio sequence. If no matching position with a cumulative deviation value less than the preset synchronization deviation tolerance value is found after scanning all positions in the ratio sequence, the signal processing logic determines that the received signal sequence does not contain a valid synchronization ratio pattern segment, abandons the current reception, clears the detection buffer, and waits for the next round of signal detection.

[0049] In another preferred embodiment of the present invention, the process of performing neighborhood discrimination on the matched ratio, outputting bit values, and reconstructing the measurement data summary in step S5 is as follows: After successfully locating the start of the data payload segment, the signal processing logic initiates the payload discrimination process. Starting with the first quotient of the data payload segment, the process sequentially extracts each quotient for bit-by-bit decision-making. The length of the data payload segment within the ratio sequence is a pre-agreed fixed value, equal to the total number of bits in the protection bit string to be transmitted. During the discrimination process, the signal processing logic maintains a bit-value assembly buffer, which is a linear storage space addressed by bit-level address.

[0050] For a given quotient value, the signal processing logic calculates the degree of deviation of that quotient value from two preset ratios. The centralized signal acquisition points internally store reference constants corresponding to the first and second preset ratios. The reference constant corresponding to the first preset ratio is the theoretical ratio of the first preset ratio, obtained by dividing the first injection duration by the first silence duration. The reference constant corresponding to the second preset ratio is the theoretical ratio of the second preset ratio, obtained by dividing the second injection duration by the second silence duration. For example, when the first injection duration is 6 and the first silence duration is 3, the reference constant corresponding to the first preset ratio is 2.0. When the second injection duration is 3 and the second silence duration is 6, the reference constant corresponding to the second preset ratio is 0.5.

[0051] The signal processing logic calculates the difference between the current quotient and the reference constant corresponding to the first preset ratio, and takes the absolute value. The resulting value is called the first deviation. The signal processing logic then calculates the difference between the current quotient and the reference constant corresponding to the second preset ratio, and takes the absolute value. The resulting value is called the second deviation. The first deviation represents the numerical difference between the current quotient and the theoretical value of the first preset ratio, while the second deviation represents the numerical difference between the current quotient and the theoretical value of the second preset ratio.

[0052] The signal processing logic compares the first deviation and the second deviation. If the first deviation is less than the second deviation, it means the current quotient value is closer to the theoretical value of the first preset ratio, and the signal processing logic determines that the original transmitted bit corresponding to the current quotient value is the first bit value. In this embodiment, the first bit value corresponds to binary 1. If the second deviation is less than the first deviation, it means the current quotient value is closer to the theoretical value of the second preset ratio, and the signal processing logic determines that the original transmitted bit corresponding to the current quotient value is the second bit value. In this embodiment, the second bit value corresponds to binary 0.

[0053] If the first deviation and the second deviation are numerically equal, the signal processing logic assumes that the current quotient is equidistant from the theoretical values ​​of the two preset ratios and cannot make a direct decision. In this case, the signal processing logic adopts the decision result of the previous quotient, that is, it directly uses the determined bit value of the immediately preceding bit as the bit value of the current bit. This equidistant adoption mechanism avoids random decision flips that may occur when individual quotients are severely distorted due to single-pass channel depth fading, thus maintaining the local continuity of the decision bit stream.

[0054] The signal processing logic sequentially writes the bit values ​​output from each decision into the bit value assembly buffer in the order of the decisions. The first bit in the bit value assembly buffer stores the bit value determined by the first quotient value of the data payload segment, the second bit stores the bit value determined by the second quotient value of the data payload segment, and so on, until all quotient values ​​of the data payload segment have been decided. The complete bit sequence finally stored in the bit value assembly buffer is the transmitted bit sequence reconstructed by the receiving end.

[0055] The signal processing logic performs cyclic redundancy check (CRC) on the transmitted bit sequence. The CRC uses the same generator polynomial and calculation rules as in S2. The signal processing logic sends all bits of the transmitted bit sequence to the CRC calculation unit, which outputs the check result. If the check result indicates that no errors occurred during transmission, the signal processing logic strips a fixed-length check bit string from the end of the transmitted bit sequence. The remaining bit sequence after stripping the check bit string is the original metering data digest injected by the sender. The signal processing logic submits this metering data digest to the associated encapsulation process in S6.

[0056] If the cyclic redundancy check result indicates an error in the transmitted bit sequence, the signal processing logic determines that the restoration has failed, discards the current transmitted bit sequence, and clears the bit value assembly buffer. The signal processing logic then continues the synchronization search process from the current synchronization pattern matching position in the detection buffer, attempting to find the next possible synchronization ratio pattern matching position and restarting the data payload segment's discrimination and restoration process.

[0057] In another preferred embodiment of the present invention, the process of establishing an association pair between the energy meter identifier and the reconstructed metering data summary in step S6, encapsulating all association pairs into a data message and attaching a reception completion time marker, and transmitting it to the energy acquisition concentrator through the local communication interface is as follows: The centralized signal acquisition point controller has an internal static random access memory (SRAM), which is divided into several equal-sized storage buffer blocks during the controller's power-on initialization phase. Each storage buffer block has a fixed starting address, uniquely determined within the memory's physical address space. The partitioning of storage buffer blocks is completed during the controller firmware compilation phase, and the number of blocks is determined by the total number of registered electricity meters installed within the metering loop served by the centralized signal acquisition point. For example, when the centralized signal acquisition point connects to 16 electricity meters, the memory is divided into 16 storage buffer blocks, each set to a size sufficient to accommodate the maximum length of the metering data summary and associated information for a single transmission.

[0058] The controller maintains a static mapping table. Each entry in the table contains two fields: the first is the energy meter identifier, and the second is the fixed starting address of the storage buffer block. The energy meter identifier is a unique number assigned to each energy meter by the energy acquisition concentrator during installation and registration. This number corresponds to the energy meter's synchronization ratio mode bit string; that is, the synchronization ratio mode bit string assigned to each energy meter is stored in pairs with the energy meter identifier within the centralized signal acquisition point controller. The static mapping table is written to the controller's non-volatile memory once during the energy meter registration phase, and only read operations are performed during operation, not write operations. After the signal processing logic reconstructs a complete metering data summary, it transmits the synchronization ratio mode bit string corresponding to the successfully matched synchronization ratio mode template to the controller's main control logic.

[0059] After receiving the synchronization ratio pattern bit string, the main control logic performs a sequential search in the static mapping table using the synchronization ratio pattern bit string as the lookup key. The search process begins with the first entry in the static mapping table, sequentially reading the synchronization ratio pattern bit string field corresponding to each entry and comparing it bit by bit with the input synchronization ratio pattern bit string. When an entry is found that matches perfectly bit by bit, the main control logic reads the corresponding energy meter identifier from that entry and uses the fixed starting address in that entry as the target storage address.

[0060] The main control logic writes the restored metering data summary into the storage buffer block pointed to by the target storage address, byte-aligned. The writing order starts from the beginning address of the storage buffer block and proceeds sequentially according to the byte order of the metering data summary, with each byte occupying one address unit within the storage buffer block. After the write operation is complete, the main control logic sets the data ready flag corresponding to the storage buffer block. The data ready flag is a Boolean state variable that corresponds one-to-one with the storage buffer block, implemented using a specific memory location or a bit in an independent register. Setting the flag indicates a logic 1 or high level, while clearing it indicates a logic 0 or low level. All data ready flags are cleared during the storage buffer block initialization phase.

[0061] The centralized signal acquisition point controller has an internal periodic reporting timer. This periodic reporting timer is a hardware timer peripheral, and its counting clock source is the controller's main clock after frequency division. The periodic reporting timer is configured for automatic reload operation, with the reload value calculated based on the required reporting period and clock frequency. The reporting period is related to the data acquisition and refresh cycle of the distribution network metering data; for example, if the acquisition cycle is 15 minutes, the reporting period is also set to 15 minutes. The periodic reporting timer starts counting upon power-on initialization. When the count value reaches the reload value, an overflow event is generated. This overflow event triggers a timer overflow interrupt request, and the timer automatically reloads the reload value into the counter and begins a new round of decrementing counting.

[0062] Within the timer overflow interrupt service routine, the main control logic executes a polling and reading process of the storage buffer blocks. Starting with the storage buffer block corresponding to the smallest energy meter identifier, the main control logic sequentially queries the data readiness flags of each storage buffer block. The query order follows the ascending order of the energy meter identifiers; that is, it first queries the storage buffer block with the smallest identifier number, then the storage buffer block with the second smallest identifier number, and so on, until all storage buffer blocks have been queried.

[0063] For the currently queried storage buffer block, if its data ready flag is cleared, the main control logic skips the storage buffer block and moves the pointer to the next storage buffer block. If the data ready flag of the current storage buffer block is set, the main control logic reads all metering data summaries starting from the beginning address of the storage buffer block, and concatenates the read metering data summaries with the corresponding energy meter identifier and the timestamp of the current cycle's reporting timer overflow time to form a single record. The timestamp is taken from the controller's internal real-time clock module, which is continuously powered by a battery and maintains complete time information for year, month, day, hour, minute, and second. The timestamp format is uniformly 8-byte compressed encoding. The concatenation order of a single record is timestamp first, energy meter identifier in the middle, and metering data summary last. There are no separators between the segments, and the reading program accurately splits them according to the pre-agreed fixed length of each segment.

[0064] After the main control logic finishes reading a record, it immediately clears the data ready flag of the storage buffer block, restoring it to a zeroed state. This clearing operation signifies that the metering data summary in the storage buffer block has been successfully moved to the reporting record, and the storage buffer block becomes idle and overwriteable, awaiting the next restore write.

[0065] The main control logic sorts all individual records collected during this interrupt service routine in ascending order by their electricity meter identifiers. The sorting method compares the numerical values ​​of the electricity meter identifier field in each record, placing records with smaller identifier values ​​first, and those with larger identifier values ​​last. After sorting, the main control logic adds a header structure to the beginning of the sorted record sequence. The header structure contains two fixed fields: field one is the total number of records, and field two is the overall cyclic redundancy check (CRC) code calculated for all subsequent record sequences. The complete data block after adding the header constitutes the data message to be sent. The main control logic sends the data message byte-by-byte to the power acquisition concentrator via a general asynchronous receiver / transmitter (GARS) interface. The transmission baud rate, data bit width, stop bits, and checksum are set according to the pre-agreed communication parameters between the interface parties. After sending, the interrupt service routine returns, waiting for the next timer overflow event.

[0066] In another preferred embodiment of the present invention, when the input metering data reading command involves multiple energy meters simultaneously, the method for distinguishing signals from different energy meters is as follows: In deployment scenarios where multiple energy meters are simultaneously connected to the same metering circuit on the low-voltage side of a distribution transformer, the signal component received by the centralized signal acquisition point is a mixed signal resulting from the linear superposition of discontinuous pulse trains injected by each energy meter in the distribution circuit. To achieve the separation and reconstruction of signals from each energy meter, each energy meter is assigned a unique synchronization ratio mode bit string during factory setup or installation registration. The synchronization ratio mode bit string is a fixed-length sequence of 6 binary bits, and different combinations of these values ​​constitute multiple usable synchronization codewords. The allocation principle for the synchronization ratio mode bit string is that the number of different bits between any two energy meters' synchronization ratio mode bit strings must exceed a preset distinguishing lower limit. The number of different bits refers to the number of bits with different values ​​compared bit by bit after aligning the two synchronization ratio mode bit strings. For example, the 6-bit bit string 101100 and the 6-bit bit string 100011 have different bit values ​​in the second, third, fifth, and sixth bits, resulting in a difference of 4 bits. The preset distinction threshold is set to 3, meaning that at least 3 bits in any two synchronization ratio pattern bit strings are inconsistent. This constraint ensures that when synchronization ratio pattern templates from different energy meters are matched in parallel at the receiving end, even if the quotient of one or two bits changes across the preset ratio neighborhood due to channel noise interference, each template can still maintain sufficient distinguishability and will not be confused by a small number of misjudged bits.

[0067] During the S2 execution phase, each energy meter independently generates a modulation unit sequence based on its assigned synchronization ratio mode bit string. Taking the synchronization ratio mode bit string 101100 as an example, the microcontroller of this energy meter maps these 6 bits bit-by-bit into 6 consecutive modulation units. Bit 1 is mapped to the first preset ratio, and bit 0 is mapped to the second preset ratio, forming a synchronization ratio mode segment unique to this energy meter. The synchronization ratio mode segments of different energy meters exhibit different alternating high and low templates in the ratio sequence. The energy meters then convert their respective protection bit strings to be transmitted into data payload segments and place their respective synchronization ratio mode segments before the data payload segments, combining them to form a complete modulation unit sequence carrying their respective identifiers, which is then injected into the power distribution circuit.

[0068] During the S5 execution phase, the centralized signal acquisition point controller internally stores the synchronization ratio pattern templates for all registered energy meters within its jurisdiction. Each synchronization ratio pattern template is an array consisting of six target ratios, the values ​​of which are determined by the theoretically preset ratios mapped to each bit of the corresponding energy meter's synchronization ratio pattern bit string. When the signal processing logic extracts the ratio sequence from the received signal, the sequence is simultaneously sent to multiple parallel template matching channels. Each template matching channel corresponds to a synchronization ratio pattern template for one registered energy meter, and each channel operates independently in hardware without blocking the others.

[0069] Each template matching channel maintains an independent sliding window pointer and a cumulative deviation value register. The sliding window pointer initially points to the first quotient value of the ratio sequence. After extracting six consecutive quotient values, it performs bit-by-bit subtraction on the six target ratio values ​​of the synchronization ratio mode template bound to that channel, takes the absolute value, and accumulates the sum. The accumulated result is stored in the cumulative deviation value register. If the cumulative deviation value is less than a preset synchronization deviation tolerance value, the template matching channel outputs a matching success signal and simultaneously outputs the current quotient value position pointed to by the sliding window pointer as the synchronization mode matching position. If the cumulative deviation value does not meet the tolerance condition, the sliding window pointer moves forward by one quotient value step, re-extracts six quotient values, and recalculates the cumulative deviation value. This process is independent of other template matching channels.

[0070] When the cumulative deviation value of a certain template matching channel is less than the preset synchronization deviation tolerance value for the first time, the data frame of the energy meter corresponding to that channel is determined to be successfully captured. The centralized signal acquisition point controller immediately starts the load restoration process corresponding to the energy meter, shifts the synchronization mode matching position backward by 6 quotient positions to define the starting point of the data load segment, performs neighborhood discrimination on each quotient value within the data load segment, and restores the metering data summary of the energy meter.

[0071] When the cumulative deviation values ​​of multiple template matching channels are all below the preset synchronization deviation tolerance value at the same or similar times, the centralized signal acquisition point controller determines that multiple energy meters' data frames have been captured simultaneously. The controller creates an independent data restoration context for each successfully captured energy meter. The data restoration context is a dynamically allocated memory area used to store the starting position of the data payload segment corresponding to that energy meter, the restored bit value sequence, and the restoration progress pointer. There is no shared data between the data restoration contexts; they are completely isolated from each other. The controller schedules each restoration context using time-slice round-robin or interrupt priority, sequentially or in parallel reading the quotient value from its respective starting position and completing neighborhood discrimination and bit reconstruction. This multi-context independent restoration mechanism ensures that even when the modulation unit sequences injected by multiple energy meters on the same bus overlap in the time and ratio domains, the data from each meter can still be reliably separated based on template differences.

[0072] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for real-time transmission of electricity metering information for smart grids, characterized in that, Includes the following steps: S1. Input the metering data reading command for multiple energy meters to be read in the target metering loop, and obtain the metering data summary to be transmitted for each energy meter; S2. Convert the measurement data summary into a modulation unit sequence. The ratio of the injection segment duration to the silence interval of each modulation unit is selected from one of two preset ratios based on the current bit value. Specifically, this includes: performing cyclic redundancy check (CRC) calculations on the measurement data summary, concatenating the check bit string to the end of the original bit sequence of the measurement data summary to form a protection bit string to be transmitted; pre-storing the injection segment duration corresponding to the first preset ratio as the first injection duration value and the silence interval duration as the first silence duration value, and the injection segment duration corresponding to the second preset ratio as the second injection duration value and the silence interval duration as the second silence duration value, wherein the first injection duration value is greater than the second injection duration value and the first silence duration value is less than the second silence duration value; pre-storing a synchronization ratio pattern bit string consisting of six binary bits, sequentially mapping each bit of the synchronization ratio pattern bit string to a modulation unit, mapping binary '1' to the first preset ratio value and binary '0' to the second preset ratio value, generating a synchronization ratio pattern segment composed of six modulation units; converting each bit of the protection bit string to be transmitted into the preset ratio value of each modulation unit in the data payload segment according to the same rule, and arranging the synchronization ratio pattern segment before the data payload segment to form a modulation unit sequence; S3. For a single energy meter, receive the time base pulse, determine the injection segment duration and the silence interval duration according to the ratio of the modulation unit, apply a fixed frequency drive pulse train within the injection segment duration, and stop applying it within the silence interval duration. S4. Continuously sample the received signal at the centralized signal acquisition point, detect the start and end times of the injection segment through the envelope threshold and calculate its duration, and obtain the silence interval duration from the time difference between adjacent injection segments. S5. Calculate the ratio of each pair of durations to obtain the ratio sequence, search for the synchronization ratio pattern, perform neighborhood discrimination on the matched ratios, output the bit value and reconstruct the metering data summary. Specifically, this includes: sequentially extracting each quotient value from the beginning of the data payload segment; calculating the absolute difference between the current quotient value and the reference constant corresponding to the first preset ratio and the reference constant corresponding to the second preset ratio to obtain the first deviation and the second deviation; if the first deviation is less than the second deviation, it is determined to be the first bit value; if the second deviation is less than the first deviation, it is determined to be the second bit value; if the first deviation is equal to the second deviation, the determination result of the previous quotient value is used; concatenating all bit values ​​in sequence to obtain the transmission bit sequence; performing cyclic redundancy check on the transmission bit sequence; after passing the check, stripping the check bit string to restore the measurement data summary; S6. Establish an association pair between the electricity meter identifier and the recombined metering data summary, encapsulate all association pairs into a data message and attach a reception completion time marker, and transmit it to the electricity acquisition concentrator through the local communication interface.

2. The method for real-time transmission of electricity metering information for smart grids according to claim 1, characterized in that, In step S3, the injection segment duration and the silence interval duration are determined based on the ratio of the modulation units. A fixed frequency drive pulse train is applied during the injection segment duration, and the application is stopped during the silence interval duration. The ratio decoding circuit reads the preset ratio type selected by the current modulation unit. When the preset ratio type is the first preset ratio, the first injection duration value is loaded into the injection duration counter and the first silence duration value is loaded into the interval duration counter. When the preset ratio type is the second preset ratio, the second injection duration value is loaded into the injection duration counter and the second silence duration value is loaded into the interval duration counter. The injection duration counter starts counting down from the effective time of the time base pulse. During the counting period, an enable level is output to the drive pulse generator. The drive pulse generator outputs a drive pulse train to the controllable switching element control terminal at a fixed repetition frequency. The enable level is deactivated when the injection duration counter returns to zero. The interval duration counter starts counting down when the injection duration counter returns to zero. During the counting period, the enable level is continuously turned off. When the interval duration counter returns to zero, the current modulation unit ends and waits for the next effective edge of the time base pulse.

3. The method for real-time transmission of electricity metering information for smart grids according to claim 1, characterized in that, In step S4, the process of continuously sampling the received signal at the centralized signal acquisition point, detecting the start and end times of the injection segment through the envelope threshold and calculating its duration, and obtaining the silence interval duration from the time difference between adjacent injection segments is as follows: The signal components coupled to the signal receiving loop are subjected to bandpass filtering. The center frequency of the passband of the bandpass filter is aligned with the fundamental frequency of the driving pulse train. The filtered signal is continuously sampled to obtain the original sampled value sequence. The original sampled value sequence is squared and then a moving average is performed to obtain a smooth envelope sequence. Each envelope value in the smooth envelope sequence is compared with a preset sensing threshold. When the envelope value crosses from below the preset sensing threshold to above the preset sensing threshold, the corresponding sampling time is recorded as the start time of the injection segment. When the envelope value crosses from above the preset sensing threshold to below the preset sensing threshold, the corresponding sampling time is recorded as the end time of the injection segment. The end time of the same injection segment is subtracted from the start time to obtain the measured value of the duration of the injection segment. The start time of the current injection segment is subtracted from the end time of the previous injection segment to obtain the measured value of the duration of the silence interval.

4. The method for real-time transmission of electricity metering information for smart grids according to claim 1, characterized in that, In step S5, the process of calculating the ratio of each pair of durations to obtain a ratio sequence and searching for a synchronization ratio pattern is as follows: The measured values ​​of the injection segment duration and the silence interval duration of multiple consecutive modulation units are calculated one by one. All quotients are arranged in the order of appearance of the modulation units to form a ratio sequence. Starting from the first quotient of the ratio sequence, six consecutive quotients are extracted as the current comparison window. The absolute values ​​of the differences between the six quotients in the current comparison window and the six target ratios of the synchronization ratio pattern template are calculated bit by bit and accumulated to obtain the cumulative deviation value. If the cumulative deviation value is less than the preset synchronization deviation tolerance value, the starting position of the current comparison window is marked as the synchronization pattern matching position, and the quotient immediately following the synchronization pattern matching position is taken as the starting point of the data payload segment. If the cumulative deviation value is greater than or equal to the preset synchronization deviation tolerance value, the comparison window will be moved to the next quotient position and six quotient values ​​will be re-extracted for comparison. This process will be repeated until all positions in the ratio sequence have been searched.

5. The method for real-time transmission of electricity metering information for smart grids according to claim 1, characterized in that, In step S6, the process of establishing an association pair between the electricity meter identifier and the reconstructed metering data summary, encapsulating all association pairs into a data message and attaching a reception completion time marker, and transmitting it to the electricity acquisition concentrator through the local communication interface is as follows: Within the centralized signal acquisition point controller, a storage buffer block is statically allocated for each registered energy meter. The fixed starting address of the storage buffer block is mapped one-to-one with the energy meter identifier. After each metering data summary is reconstructed, the energy meter identifier is determined based on the matched synchronization ratio pattern. The metering data summary is written to the corresponding storage buffer block and the data ready flag is set. A periodic reporting timer is set. When the periodic reporting timer overflows, the data ready flags of each storage buffer block are queried in turn. The ready metering data summary, the corresponding energy meter identifier, and the timestamp of the periodic reporting timer overflow are concatenated into a single record, and the data ready flag of the corresponding storage buffer block is cleared. All records are sorted in ascending order by energy meter identifier, and after adding the total number of records and the cyclic redundancy check code, they are encapsulated into a data packet and sent to the energy acquisition concentrator through the universal asynchronous transceiver interface.

6. The method for real-time transmission of electricity metering information for smart grids according to claim 1, characterized in that, When the input metering data reading command involves multiple energy meters simultaneously, the method for distinguishing signals from different energy meters is as follows: In S1, a corresponding synchronization ratio mode bit string is pre-assigned to each energy meter. The number of different bits between the synchronization ratio mode bit strings of different energy meters exceeds a preset distinguishing lower limit. The length of the synchronization ratio mode bit string is uniformly six bits. In S2, each energy meter generates a corresponding synchronization ratio mode segment and data payload segment according to its assigned synchronization ratio mode bit string. The combined modulation unit sequence contains its own synchronization ratio mode. In S5, the ratio sequence is compared in parallel with all the stored synchronization ratio mode templates. Each synchronization ratio mode template independently performs sliding window comparison and records the cumulative deviation value and matching position. When the cumulative deviation value of any synchronization ratio mode template is less than the preset synchronization deviation tolerance value, the data payload segment after the matching position of the synchronization ratio mode template is used to restore the metering data summary of the corresponding energy meter. When multiple synchronization ratio mode templates are simultaneously less than the preset synchronization deviation tolerance value, the metering data summary of each energy meter is restored independently.

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