A three-phase power parameter wireless synchronous measurement and vector analysis method and system

Abstract

The present application belongs to the technical field of power system measurement, and relates to a three-phase power parameter wireless synchronous measurement and vector analysis method and system, comprising the following steps: generating and broadcasting a synchronization pulse code containing trigger phase information; generating a predicted phase angle; obtaining a comprehensive phase deviation value; performing dynamic characteristic separation processing on the comprehensive phase deviation value to generate a slowly-varying propagation delay characteristic and a transient predicted error characteristic; injecting the predicted error characteristic into a local phase predictor for calibration; collecting local phase voltage / current data based on the compensated sampling time, calculating the fundamental effective value and the phase angle relative to the local calibration time reference; and encapsulating the fundamental effective value, the phase angle and the local timestamp into a simplified data packet and transmitting the data packet to an analysis terminal. The present application solves the problem that the satellite timing in the traditional mode is rejected in the indoor or underground scene of a transformer substation, and is prone to electromagnetic interference, which leads to synchronization interruption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power system measurement, and relates to a three-phase power parameter wireless synchronization measurement and vector analysis method and system. BACKGROUND

[0002] In the field of three-phase parameter measurement of power systems, the phase synchronization accuracy between distributed nodes directly affects the reliability of power quality analysis. Traditional measurement methods rely on independent acquisition of voltage and current waveforms of each phase. Due to differences in the spatial distribution of nodes, signal air propagation delay and local clock drift cause phase reference misalignment. Especially when the grid frequency fluctuates or there is harmonic interference, the instantaneous phase angle deviation collected by different nodes can reach several milliseconds, causing three-phase vector synthesis error to exceed the limit, which cannot meet the accuracy requirements of fault location and unbalance degree calculation.

[0003] The existing technology mainly uses satellite time service or wired synchronization scheme to solve this problem. Satellite time service broadcasts absolute time reference to each node through GPS / Beidou receiver, achieving microsecond-level hard synchronization; wired synchronization transmits clock signals using IRIG-B encoding or optical fiber network. Some improved schemes use software synchronization protocols, such as the Precision Time Protocol based on IEEE 1588, which calculates transmission delay and corrects clock drift through master-slave node message exchange.

[0004] Based on the above problems, the traditional method has the problems that satellite time service is prohibited in indoor or underground scenarios of substations, and is easily interrupted by electromagnetic interference. SUMMARY

[0005] In a first aspect, the application provides a three-phase power parameter wireless synchronization measurement and vector analysis method, which adopts the following technical scheme:

[0006] A three-phase power parameter wireless synchronization measurement and vector analysis method, comprising the following steps:

[0007] S1, acquiring a grid A-phase voltage waveform, generating and broadcasting a synchronization pulse code containing trigger phase information at a predetermined accurate phase point when the phase tracking state reaches stability;

[0008] S2, receiving the synchronization pulse code and recording the reception timestamp, while acquiring the local phase frequency characteristics, and generating a predicted phase angle by running a local phase predictor;

[0009] S3, calculating a theoretical expected phase angle based on three-phase phase difference constraints and trigger phase information, comparing it with the predicted phase angle to obtain a comprehensive phase deviation value;

[0010] S4, performing dynamic feature separation processing on the comprehensive phase deviation value to generate a slowly varying propagation delay feature caused by signal air propagation time, and a transient prediction error feature caused by local predictor drift;

[0011] S5、According to the propagation delay characteristics, the equivalent propagation time is calculated and the local sampling time is adjusted, and the prediction error characteristics are injected into the local phase predictor for calibration;

[0012] S6、Based on the compensated sampling time, the local voltage / current data is collected, the fundamental effective value and the phase angle relative to the local calibration time reference are calculated;

[0013] S7、The fundamental effective value, the phase angle and the local timestamp are packaged into a simplified data packet and transmitted to an analysis terminal.

[0014] Further schemes of the present application, generate and broadcast synchronization pulse encoding containing trigger phase information, including the following steps:

[0015] The voltage waveform of the A-phase of the power grid is continuously monitored by a preset phase tracking device;

[0016] When the maximum phase angle offset of the continuous N cycles is less than the preset offset threshold, it is determined that the phase tracking state reaches stability;

[0017] The predetermined accurate phase point triggers the synchronization pulse generation unit, and encodes the current instantaneous phase angle to generate the synchronization pulse encoding.

[0018] Further schemes of the present application, generate a predicted phase angle, including the following steps:

[0019] The receiving timestamp is latched when receiving the synchronization pulse encoding through the hardware interrupt mechanism;

[0020] The local signal monitoring device detects the local zero-crossing point and updates the power grid frequency characteristics;

[0021] The power grid frequency characteristics are input into the local phase predictor, and the predicted phase angle sequence is generated by incremental calculation and the output value is frozen at the receiving timestamp.

[0022] Further schemes of the present application, get the comprehensive phase deviation value, including the following steps:

[0023] Based on the inherent three-phase phase difference constraint of the power grid, the main node trigger phase information in the synchronization pulse encoding is combined to calculate the theoretical expected phase angle of the local phase;

[0024] The theoretical expected phase angle is directly compared with the predicted phase angle generated by the local phase predictor at the synchronization pulse receiving timestamp, and the comprehensive phase deviation value is obtained by subtraction operation.

[0025] Further schemes of the present application, the comprehensive phase deviation value is processed by dynamic characteristic separation, including the following steps:

[0026] inputting the integrated phase deviation value into a dynamic feature separation processor;

[0027] The slowly changing component in the integrated phase deviation value is extracted by a first-order low-pass filter and is identified as a propagation delay feature; after the slowly changing component is removed by subtraction operation, the remaining high-frequency fluctuation component is identified as a prediction error feature;

[0028] Based on the physical characteristics that the propagation delay feature changes slowly over time and the prediction error feature fluctuates rapidly, the two types of features are effectively separated by digital filtering technology.

[0029] In a further aspect of the application, the prediction error feature is injected into the local phase predictor for calibration, including the following steps:

[0030] According to the propagation delay feature and the locally measured real-time frequency, the equivalent propagation time caused by the over-the-air transmission of the radio signal is calculated;

[0031] The prediction error feature is input into the proportional-integral regulator of the local phase predictor, and a phase correction amount is generated by proportional-integral operation and is superimposed in real time on the angle cumulative value of the local phase predictor to suppress its inherent drift error.

[0032] In a further aspect of the application, based on the compensated sampling time, the local voltage / current data is collected, the fundamental effective value and the phase angle relative to the local calibration time reference are calculated, including the following steps:

[0033] Based on the adjusted sampling time, the analog-to-digital converter is triggered to obtain the voltage / current raw data;

[0034] The fundamental component is extracted by a digital band-pass filter;

[0035] The fundamental effective value is calculated by a full-cycle integration algorithm;

[0036] The phase angle is calculated based on the sampling time offset with respect to the current cycle zero-crossing point.

[0037] In a further aspect of the application, the fundamental effective value, the phase angle and the local timestamp are packaged into a simplified data packet and transmitted to an analysis terminal, including the following steps:

[0038] The obtained fundamental effective value, phase angle and local timestamp are combined into a fixed format transmission unit, and the transmission unit is packaged into a simplified data packet according to a predetermined protocol;

[0039] The transmission process adopts a time division multiple access mechanism with collision avoidance to ensure that no data collision occurs when multiple nodes work cooperatively;

[0040] The time sequence is aligned according to the local timestamp, and the voltage and current vector diagram is reconstructed based on the inherent phase relationship of the three phases.

[0041] In a further aspect, the time division multiple access mechanism comprises the steps of:

[0042] Each slave node sends data in a fixed time window;

[0043] The time window position is determined by the last byte of the node MAC address modulo the time slot base value broadcasted by the master node, and the sending time slot is The total number of time slots.

[0044] In a second aspect, the application provides a three-phase power parameter wireless synchronous measurement and vector analysis system, which adopts the following technical scheme:

[0045] A three-phase power parameter wireless synchronous measurement and vector analysis system comprises the following modules:

[0046] A master node phase synchronization module is configured to obtain an A-phase voltage waveform of a power grid, and generate and broadcast a synchronization pulse code containing trigger phase information at a predetermined accurate phase point when a phase tracking state reaches stability;

[0047] A slave node signal processing module is configured to receive the synchronization pulse code and record a receiving time stamp, and obtain a local phase predictor to generate a predicted phase angle while obtaining a frequency characteristic of the power grid;

[0048] A phase deviation calculation module is configured to calculate a theoretically expected phase angle based on a three-phase phase difference constraint and trigger phase information, and compare the theoretically expected phase angle with the predicted phase angle to obtain a comprehensive phase deviation value;

[0049] A dynamic characteristic separation module is configured to perform dynamic characteristic separation processing on the comprehensive phase deviation value to generate a slowly-varying propagation delay characteristic caused by signal air propagation time and a transient prediction error characteristic caused by local predictor drift;

[0050] A double-path calibration module is configured to calculate an equivalent propagation time according to the propagation delay characteristic and adjust a local sampling time, and inject the prediction error characteristic into the local phase predictor for calibration;

[0051] A vector parameter calculation module is configured to collect A-phase voltage / current data based on the compensated sampling time, and calculate a fundamental effective value and a phase angle relative to a local calibration time reference;

[0052] A data transmission module is configured to encapsulate the fundamental effective value, the phase angle and a local time stamp into a simplified data packet and transmit the data packet to an analysis terminal.

[0053] In summary, the application has the following beneficial technical effects:

[0054] 1. Through dynamic separation of the double interference sources of propagation delay and prediction error, and respectively performing hardware sampling time compensation and software predictor closed-loop calibration, the spatial transmission delay and local clock drift are cooperatively suppressed. The phase reference broadcast by the master node is converted into the theoretical phase difference of the slave node, compared with the local prediction value to generate the comprehensive deviation, and after feature separation, it is corrected in a targeted manner: the hardware compensation directly adjusts the ADC sampling trigger timing to offset the air delay, and the software calibration dynamically corrects the predictor cumulative error through a proportional-integral algorithm;

[0055] 2. The local phase predictor combines a dynamic feature separation mechanism to effectively deal with power grid frequency fluctuations and sudden disturbances. The predictor tracks frequency changes in an incremental calculation mode reset by the zero-crossing point, avoiding the spread of cumulative errors; the feature separation processor extracts the slowly drifting signal propagation delay feature through low-pass filtering, automatically filtering transient spikes caused by harmonic disturbances. When the signal propagation delay slowly drifts due to changes in environmental temperature and humidity, the system continuously updates the compensation value to maintain synchronization stability;

[0056] 3. Innovatively use the inherent phase difference constraint of the power grid to build a relative time reference, breaking the dependence of traditional synchronization technology on GPS / Beidou signals. The master node locks the A-phase voltage zero-crossing point through a phase-locked loop to generate a synchronization pulse, and the slave node calculates the local phase theoretical value based on the fixed phase difference of 120° / 240°, and then realizes closed-loop tracking through the local predictor. Even in satellite-denied environments such as underground substations and densely packed factories, the system can still maintain sub-millisecond synchronization between nodes through radio broadcasts. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, and the drawings are used to provide further understanding of the present application, and for those skilled in the art, no creative labor is needed to obtain other drawings from these drawings.

[0058] Fig. 1 The flowchart of the embodiment in the present application is disclosed.

[0059] Fig. 2 The structural schematic diagram of the embodiment in the present application is disclosed. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0061] The application is illustrated in detail below with reference to the accompanying drawings Figs. 1-2 The application is illustrated in detail below with reference to the accompanying drawings

[0062] The application is illustrated in detail below with reference to the accompanying drawings Fig. 1 The application provides a three-phase power parameter wireless synchronous measurement and vector analysis method, comprising the following steps:

[0063] S1, acquiring a voltage waveform of a power grid A phase, and generating and broadcasting a synchronization pulse code containing trigger phase information at a predetermined accurate phase point when a phase tracking state reaches stability;

[0064] S2, receiving the synchronization pulse code and recording a receiving time stamp, simultaneously acquiring a local phase predictor to generate a predicted phase angle;

[0065] S3, calculating a theoretically expected phase angle based on a three-phase phase difference constraint and trigger phase information, comparing the theoretically expected phase angle with the predicted phase angle to obtain a comprehensive phase deviation value;

[0066] S4, performing dynamic characteristic separation processing on the comprehensive phase deviation value to generate a slowly-varying propagation delay characteristic caused by signal air propagation time and a transient prediction error characteristic caused by local predictor drift;

[0067] S5, calculating an equivalent propagation time according to the propagation delay characteristic and adjusting a local sampling time, and simultaneously injecting the prediction error characteristic into the local phase predictor for calibration;

[0068] S6, collecting a local voltage / current data based on the compensated sampling time, calculating a fundamental effective value and a phase angle relative to a local calibration time reference;

[0069] S7, encapsulating the fundamental effective value, the phase angle and a local time stamp into a simplified data packet and transmitting the data packet to an analysis terminal.

[0070] In one embodiment of the application, step S1 comprises the following steps:

[0071] A master node deployed in the power grid A phase continuously monitors a voltage waveform of the power grid A phase by using a phase tracking device, and generates and wirelessly broadcasts a synchronization pulse code at a predetermined accurate phase point when a phase tracking state reaches stability.

[0072] Specifically, the master node deployed on phase A of the power grid continuously captures the phase A voltage waveform signal through its built-in phase tracking device. This phase tracking device operates based on the principle of a digital phase-locked loop (PLL) and represents the combination of integrated hardware circuitry and firmware within the master node. The phase tracking device first periodically samples the phase A voltage signal and calculates the real-time grid frequency by comparing the zero-crossing time difference of voltage waveforms in adjacent periods. It then tracks the instantaneous phase angle of the voltage waveform through integration, generating continuous phase angle trajectory data that satisfies the following formula:

[0073]

[0074] in, for Instantaneous phase angle of phase A of the power grid at any given time, in degrees; for The instantaneous phase angle of phase A of the power grid at a given moment, in degrees. The initial value is reset to 0° at the zero-crossing point. This refers to the real-time power grid frequency, in Hz. (Number of cycles per second) is measured by a hardware zero-crossing detection circuit; The sampling interval is fixed and determined by the ADC sampler; the unit is seconds (S). Calculated based on the time difference between adjacent zero crossings:

[0075]

[0076] in, and Indicates the time between adjacent zero crossings; This indicates the real-time power grid frequency.

[0077] The phase tracking device continuously detects a preset number of complete cycles. When the maximum phase angle offset between adjacent cycles is less than a set offset threshold (the offset threshold is set according to the application scenario, with a typical value of 0.1 degrees), the phase tracking state is determined to be stable. The master node, based on the locked phase angle trajectory, triggers the synchronization pulse generation unit at a predetermined precise phase point (not a voltage zero-crossing point; typically a 30-degree phase position is chosen to avoid steep waveform regions). The synchronization pulse generation unit encodes the instantaneous phase angle value at the current moment into a synchronization pulse code. This synchronization pulse code is then incorporated into the GPS pulse timing or master node clock broadcast mechanism and broadcast to all slave nodes.

[0078] The phase tracking device includes a voltage transformer, an ADC sampler, and a digital phase-locked loop logic unit. The voltage transformer converts the high-voltage signal of phase A into a low-voltage signal. The ADC sampler collects the low-voltage signal at a fixed sampling interval (e.g., 10kHz). The digital phase-locked loop logic unit determines the real-time grid frequency by calculating the time difference between adjacent zero-crossing points.

[0079] Phase tracking state reaches stability refers to the phase angle trajectory output by the digital phase-locked loop logic unit in the next N cycles (N≥5), the maximum offset of the phase angle in adjacent cycles is less than the set offset threshold; the number of cycles meeting the condition is recorded by a software counter, and the state flag bit is triggered when the continuous counting reaches N.

[0080] The offset threshold is set according to the accuracy requirement of phase stability in the application scene, and a typical value is 0.1 degrees, which is relaxed to 0.5 degrees in the industrial vibration monitoring scene, and is tightened to within 0.01 degrees in the super-sensitive scene such as precise optical measurement. The predetermined accurate phase point refers to the time position calculated dynamically according to the power grid frequency, and the position of 30 degrees is usually selected to avoid the steep region of the waveform.

[0081] The synchronization pulse coding refers to a data structure including two fields, field 1 is a 4-byte floating point number, recording the accurate phase information of the trigger time of the master node; and field 2 is a 2-byte integer, recording the millisecond timestamp of the local clock of the master node.

[0082] The GPS pulse time service is to receive the pulse signal transmitted by the GPS satellite every second, and to realize the microsecond-level hard synchronization of cross-regional devices by using the satellite atomic clock, which is suitable for power system synchronous phasor measurement, 5G base station and other scenes requiring high-precision absolute time reference.

[0083] The master node clock broadcast mechanism is to preset the master node to periodically broadcast the time reference value generated by the local high-stability clock in the data packet, to realize the sub-millisecond relative time synchronization of the local area network, and is suitable for the scene of industrial Internet of Things, Internet of Vehicles and the like which does not require absolute time but requires internal consistency.

[0084] For example, after the master node is installed on the phase bus of the power distribution room A of the factory, the phase tracking device continuously monitors the voltage waveform. When the angle jumps of the same 30° phase point in adjacent cycles in the next 5 cycles are all less than the set offset threshold 0.08° (for example, 30.02° in the first cycle, 30.07° in the second cycle, 30.03° in the third cycle, 30.01° in the fourth cycle, and 30.05° in the fifth cycle), it is determined that the phase tracking state reaches stability. The master node starts the synchronization pulse generation unit immediately: taking the latest zero-crossing point as the reference, according to the current cycle length 20 ms (50 Hz power grid), it is calculated that the 30° phase point is located at 1.667 ms after the zero-crossing point, and the instantaneous phase angle is 30.05° at this moment, and the synchronization pulse coding "30.05|12345" is generated by combining the local clock stamp "12345 ms". The synchronization pulse coding is broadcast and sent through the LoRa wireless module, and the slave node realizes synchronization verification by comparing the received synchronization pulse coding with the local monitoring result.

[0085] In one embodiment of the application, step S2 comprises the following steps:

[0086] The slave node synchronously receives the pulse and listens to the local power grid signal. The slave node deployed in phase B, phase C or current measurement point receives the synchronization pulse code and records the receiving timestamp, while continuously acquiring the local phase voltage signal through the local signal listening device and executing the local phase predictor to generate the predicted phase angle sequence.

[0087] Specifically, after the slave node captures the synchronization pulse code broadcast by the master node through the wireless receiving module, it immediately triggers the hardware interrupt mechanism to record the accurate receiving timestamp at that moment. The hardware interrupt mechanism refers to that when the physical layer circuit of the wireless receiving module detects the specific signal transition (such as rising edge / falling edge) of the synchronization pulse code, the physical layer circuit of the wireless receiving module immediately sends a high-priority electrical signal to the processor through a dedicated hardware line, forcing the processor to pause the current task and execute the predefined interrupt service program within microseconds or even nanoseconds. The local signal listening device built-in the slave node continuously samples the local phase voltage signal periodically, identifies the crossing point of the voltage waveform from negative to positive through the phase tracking device, calculates the time difference between adjacent zero-crossing points and takes the reciprocal to obtain the grid frequency characteristic. The grid frequency characteristic is input to the local phase predictor, which accumulates the phase angle based on the phase endpoint of the previous period as the starting point, multiplies the current measured frequency by a fixed angle step, and generates a continuously updated predicted phase angle sequence. Each zero-crossing point resets the phase angle to 0° and restarts the incremental calculation at the current frequency. The slave node synchronously freezes the real-time output value of the local phase predictor at the same microsecond-level time point when recording the synchronization pulse receiving timestamp, as the local phase predicted phase angle reference at that moment.

[0088] Wherein, the receiving timestamp refers to the microsecond-level time label generated by GPS pulse timing or the master node clock at the moment when the physical layer chip of the slave node's wireless communication module completely receives the last byte of the synchronization pulse code. The grid frequency characteristic is the instantaneous frequency value calculated by the time difference between adjacent zero-crossing points, which is updated each time a new zero-crossing point is detected.

[0089] The wireless receiving module refers to the dedicated wireless communication hardware unit in the slave node that is responsible for physically receiving the synchronization pulse code signal sent by the master node through radio waves, real-time demodulating the signal by its underlying hardware circuit, detecting specific transition edges (such as rising edge / falling edge) to directly trigger interrupts.

[0090] The local signal listening device includes a voltage signal conversion circuit that converts the local high voltage into a processable low voltage analog signal, an analog-to-digital converter that samples the voltage signal at a fixed rate, and a zero-crossing detection comparator that outputs a transition pulse when the sampling value changes from negative to positive. The transition pulse of the zero-crossing detection comparator triggers the wireless receiving module to record the receiving timestamp, and the time difference between adjacent transitions is the period length.

[0091] The predicted phase angle refers to a real-time phase angle value output by the local phase predictor at a synchronization pulse receiving timestamp. The real-time phase angle value is latched to a cache area when a receiving interrupt occurs, thereby ensuring strict correspondence with the receiving timestamp.

[0092] The local phase predictor is composed of an initialization module and an incremental calculation module. The initialization module resets the phase angle to 0° each time a zero-crossing point is detected, and the incremental calculation module performs incremental calculation at each sampling time: the phase angle of the current sampling point is the sum of the phase angle of the previous sampling point and a fixed angle step.

[0093] For example, a slave node deployed in the B-phase of a factory distribution room detects adjacent zero-crossing points at 100.00 ms and 120.05 ms, respectively, and thus calculates an instantaneous frequency of 49.88 Hz. The local phase predictor takes 49.88 Hz as a reference, and under a sampling interval of 0.1 ms (10 kHz sampling rate), the fixed angle step by which the phase angle of each sampling point increases is 1.79568°. When the slave node completely receives the synchronization pulse code "30.05|12345" sent by the master node at a local clock time of 12345.678 ms, the output value of the predictor at this moment is immediately latched, and the predictor has accumulated to 118.75° when the receiving interrupt is detected. 118.75° is taken as the reference of the predicted phase angle of the receiving timestamp, and is compared with the phase information of the A-phase of the master node for subsequent comparison.

[0094] In one embodiment of the present application, step S3 includes the following steps:

[0095] The slave node calculates the theoretical phase difference and the actual phase deviation, calculates the theoretical expected phase angle of the local phase based on the inherent three-phase phase difference constraint of the power grid and the master node trigger phase information in the synchronization pulse code, and compares the theoretical expected phase angle with the predicted phase angle generated by the local phase predictor to obtain the comprehensive phase deviation value.

[0096] Specifically, after receiving the synchronization pulse code broadcast by the master node, the slave node decodes the synchronization pulse code to extract the accurate phase information of the master node trigger time. The slave node calculates the theoretical expected phase angle of the local phase based on the inherent three-phase phase difference constraint of the power grid, i.e., the fixed phase difference relationship between the A-phase, B-phase and C-phase voltage waveforms of the standard three-phase power system. Specifically, the B-phase lags behind the A-phase by 120 degrees, and the C-phase lags behind the A-phase by 240 degrees or leads the A-phase by 120 degrees. This phase difference relationship is determined by the physical characteristics of three-phase alternating current, and the slave node directly applies the fixed offset value as a reference when calculating the theoretical expected phase angle of the local phase, satisfying the following formula:

[0097]

[0098] wherein, theoretical expected phase angle of the local phase; decoded sync pulse encoding extraction master node trigger phase angle of phase A; fixed phase difference relationship between phase A, phase B and phase C voltage waveforms.

[0099] The theoretical expected phase angle is directly compared with the predicted phase angle generated by the local phase predictor at the sync pulse receiving timestamp, and the comprehensive phase deviation value is obtained by subtraction operation. The whole process relies on the sync pulse encoding provided in step S1 and the receiving timestamp and predicted phase angle recorded in step S2, ensuring the alignment of time points.

[0100] wherein, the master node trigger phase information in the sync pulse encoding refers to the field contained in the sync pulse encoding generated by the master node in step S1, which records the accurate phase angle value of the master node at the time of triggering the sync pulse, which is received and decoded by the slave node through wireless broadcast.

[0101] Theoretical expected phase angle, the slave node calculates the expected phase angle value according to the decoded master node trigger phase information and the phase difference constraint corresponding to the local phase; for the B-phase node, the calculation method is to add 120 degrees to the master node trigger phase angle value; for the C-phase node, it is to add 240 degrees or subtract 120 degrees.

[0102] The predicted phase angle generated by the local phase predictor refers to the real-time phase angle value output by the local phase predictor built-in in the slave node at the sync pulse receiving timestamp in step S2, which is latched when the receiving interrupt is received, representing the local phase voltage phase state monitored by the slave node.

[0103] The comprehensive phase deviation value refers to the difference value obtained by subtracting the predicted phase angle generated by the local phase predictor from the theoretical expected phase angle, which represents the angle deviation between the actual measurement and the theoretical expectation, which is used for subsequent error analysis.

[0104] For example, in the application of factory power distribution room, the master node is deployed in phase A and broadcasts the sync pulse encoding, the trigger phase information is 30.05 degrees, the B-phase slave node receives the sync pulse encoding and decodes the master node trigger phase information 30.05 degrees, and calculates the theoretical expected phase angle based on the three-phase phase difference constraint (B-phase lags A-phase by 120 degrees) as 150.05 degrees. The predicted phase angle generated by the local phase predictor at the receiving timestamp is 148.75 degrees. By comparing these values, i.e. 150.05 degrees minus 148.75 degrees, the comprehensive phase deviation value is 1.3 degrees.

[0105] In one embodiment of the present application, step S4 comprises the following steps:

[0106] The propagation delay feature and the prediction error feature in the phase deviation from the node are separated, and the comprehensive phase deviation value is dynamically separated and processed to distinguish the slowly varying propagation delay feature caused by the signal air propagation time and the transient prediction error feature caused by the local predictor drift.

[0107] After obtaining the comprehensive phase deviation value calculated in step S3 from the node, the comprehensive phase deviation value is input into a dynamic feature separation processor. The slowly varying component in the comprehensive phase deviation value is extracted through a first-order low-pass filter, and it is identified as the propagation delay feature. After removing the slowly varying component through subtraction operation, the remaining high-frequency fluctuation component is identified as the prediction error feature. The whole process is based on the physical characteristics that the propagation delay feature changes slowly over time and the prediction error feature fluctuates rapidly, and the effective separation of the two types of features is realized through digital filtering technology.

[0108] The dynamic feature separation processing refers to the operation of decomposing the frequency components of the input comprehensive phase deviation value using a dynamic feature separation processor, which includes a low-pass filter channel and a high-pass operation channel, and the output results of the two are processed in parallel.

[0109] The propagation delay feature refers to the low-frequency component extracted through the low-pass filter channel, and the phase lag caused by the air propagation time of the radio signal from the master node to the slave node. The change rate of the propagation delay feature value is affected by the environmental temperature and humidity, and the typical change period is greater than 10 seconds, so a first-order low-pass filter with a cutoff frequency of 0.1 Hz is used for extraction. The implementation of the first-order low-pass filter is software iterative calculation, which satisfies the following formula:

[0110]

[0111] Wherein, represents the current output value, i.e. the current result after filtering; represents the current input value, i.e. the original signal at the current sampling time; represents the previous output value, i.e. the filtering result at the previous sampling time;

[0112] represents the filtering coefficient, which is used to determine the weight of new and old data, and satisfies the following formula:

[0113]

[0114] Wherein, is a fixed sampling interval, determined by the ADC sampler; is a time constant, which determines the response speed of the filter, and is set according to the demand, and the typical value is 1~10s. The smaller, the stronger the filtering (slower response); The larger, the faster response (filtering is weakened).

[0115] The prediction error feature refers to the high-frequency component extracted by the high-pass operation channel, calculated as the integrated phase deviation value minus the propagation delay feature, reflecting the instantaneous error of the local phase predictor due to clock drift and power grid harmonic interference. The transient prediction error feature is a random fluctuation characteristic under normal power grid conditions, and its standard deviation is used as a predictor health status evaluation index.

[0116] The slowly varying propagation delay feature refers to the change between adjacent sampling points required by the first-order low-pass filter output being less than a set change threshold. If the change threshold is exceeded, it is considered that there is abnormal interference and needs to be reinitialized. The change threshold is usually determined by adding a safety margin to the maximum fluctuation value of the phase stable change in the measured historical data.

[0117] For example, the B-phase from the node measures the integrated phase deviation value as 1.3°, and the dynamic feature separation processor performs low-pass filtering with α=0.005: if the previous propagation delay feature is 0.8°, then the output is 0.005×1.3°+0.995×0.8°=0.8065°.

[0118] The prediction error feature is calculated as 1.3°-0.8065°=0.4935°, and continuous monitoring shows that the propagation delay feature slowly changes from 0.8065° to 0.809° within 10 minutes, which is consistent with the signal propagation delay characteristics; the prediction error feature randomly fluctuates within ±0.5°, reflecting the instantaneous error of the local predictor.

[0119] In one embodiment of the present application, step S5 includes the following steps:

[0120] The slave node performs dynamic hardware compensation and local phase predictor calibration, and at the same time, calculates the equivalent propagation time according to the propagation delay feature and adjusts the local sampling time to offset the air delay; the prediction error feature is fed back to the local phase predictor to correct its output value in real time.

[0121] After the slave node obtains the propagation delay feature and the prediction error feature separated in step S4, it performs a double-path correction operation. First, the equivalent propagation time caused by the air transmission of the radio signal is calculated according to the propagation delay feature, which satisfies the following formula:

[0122]

[0123]

[0124] Wherein, Equivalent propagation time, denoted as TEP, represents the physical transmission time span from the sending of a synchronization pulse to its receiving. Phase difference accumulated for master and slave nodes, master node sending time phase angle - slave node receiving time local predicted phase angle. Radian value for a complete cycle. Radian representation for phase difference accumulated for master and slave nodes. Local real-time frequency measured for slave node, representing the reciprocal of the time difference between adjacent zero-crossing points of the voltage waveform, taken from the local signal monitoring device in step S2.

[0125] The prediction error feature is input into the proportional-integral regulator of the local phase predictor, and a phase correction quantity is generated through proportional-integral operation and is superimposed in real time on the angle accumulation value of the local phase predictor to suppress its inherent drift error. The two-path correction is independently executed but shares the same clock reference, ensuring global consistency of time alignment.

[0126] wherein the dynamic hardware compensation refers to the operation of modifying the sampling trigger timing of the ADC sampler through a programmable logic device, and the actual sampling point is moved forward by subtracting the calculated equivalent propagation time from the original sampling time. The adjusted trigger signal directly drives the conversion start pin of the ADC sampler to avoid software delay.

[0127] The local sampling time adjustment is executed by a timing controller inside the FPGA offset register, which stores the basic sampling interval. After receiving the equivalent propagation time value, the trigger timing is immediately updated to: theoretical trigger point - equivalent propagation time.

[0128] The local phase predictor calibration refers to a closed-loop correction mechanism for the output value of the local phase predictor. The prediction error feature is input into a proportional-integral regulator (the proportional coefficient Kp is 0.1-0.3, and the integral time constant Ti is 0.5-2 seconds), and a phase correction quantity is output. The phase correction quantity is accumulated to the predictor angle accumulation value in each sampling period.

[0129] The phase correction quantity represents the output variable of the proportional-integral regulator. The proportional coefficient is multiplied by the current prediction error feature value to obtain a correction component based on the current instantaneous deviation. The proportional coefficient is first divided by the integral time constant to obtain an integral gain coefficient. Then, the integral gain coefficient is multiplied by the historical accumulated integral value of the prediction error feature to obtain a correction component based on the accumulation of long-term deviation. The sum of the correction component based on the current instantaneous deviation and the correction component based on the accumulation of long-term deviation is the phase correction quantity of this time.

[0130] For example, when the propagation delay feature measured by the B-phase slave node is 0.8065° and the current grid frequency is 49.88 Hz, the equivalent propagation time is calculated as 44.98 The value of the equivalent propagation time is written into the FPGA offset register, and the sampling action at the original T time is advanced to T-44.98 The execution is performed. Meanwhile, for the prediction error characteristic 0.4935°, Kp=0.2 and Ti=1 second are taken:

[0131] If the integral cumulative value before this is 0.8°, the phase correction amount of this time = 0.2*0.4935+(0.2 / 1)*(0.8+0.4935)=0.0987°+0.2587°=0.3574°. The phase correction amount of this time is immediately superimposed on the local phase predictor output value, and after continuous operation, it is observed that the fluctuation range of the prediction error characteristic is reduced to ±0.1°, verifying the effectiveness of the calibration.

[0132] In one embodiment of the application, step S6 comprises the following steps:

[0133] The slave node calculates the local vector parameter under the time alignment reference, collects the local voltage / current data based on the compensated accurate sampling time, and calculates the fundamental effective value and the phase angle relative to the local calibration time reference.

[0134] Specifically, after the dynamic hardware compensation completed in step S5, the slave node triggers the analog-to-digital converter to collect the local voltage and current raw waveform data based on the adjusted accurate sampling time. The collected data is subjected to digital filtering to eliminate high-frequency interference and extract the fundamental component. The square average value of the voltage and current fundamental components in one complete power frequency period is calculated using the full-cycle integration algorithm. The arithmetic square root of the square average value is taken as the fundamental effective value, satisfying the following formula:

[0135]

[0136]

[0137] wherein, represents the voltage fundamental effective value; represents the current fundamental effective value; represents the number of sampling points in a complete cycle, ; is the voltage instantaneous value of the kth sampling point after bandpass filtering; is the current instantaneous value of the kth sampling point after bandpass filtering.

[0138] Taking the compensated local time reference as the phase zero point, the starting position of the cycle is determined by detecting the zero-crossing point of the fundamental voltage waveform from negative to positive, and the phase angle offset of the current sampling point relative to the starting point is calculated as the local phase angle, satisfying the following formula:

[0139]

[0140] wherein, is the current sampling point phase angle; is the compensated sampling time, the dynamic hardware compensation triggers; represents the current cycle zero-crossing time, provided by the step S2 local signal monitoring device; represents the current cycle length, .

[0141] The compensated accurate sampling time refers to the actual sampling trigger time point after the dynamic hardware compensation adjustment of the step S5, and the compensated accurate sampling time is started by the FPGA offset register output pulse signal to start the analog-to-digital conversion process, and the compensation value is stored in a special offset register.

[0142] The collected phase voltage / current data refers to the analog signal converted by the current transformer and the voltage transformer, and the discrete sequence after digitalization by the analog-to-digital converter at a fixed sampling rate (typical value 10 kHz), and the sequence length covers at least one complete power frequency cycle.

[0143] The local calibration time reference refers to the synchronized time reference system formed after the hardware compensation and the predictor calibration of the step S5, and the phase zero point thereof maintains a theoretical phase difference relationship with the master node.

[0144] For example, the B-phase slave node triggers sampling at the time of 12345.633 ms (44.98 ) after compensation (originally scheduled at 12345.678 ms), collects 200 voltage data points in a 50 Hz cycle (sampling rate 10 kHz), measures the current cycle zero-crossing time as 12345 ms, and the current cycle length as 20.05 ms. After taking the continuous 20 cycle data and extracting the fundamental component through digital band-pass filtering: taking the square sum of the 200 points after filtering and dividing by 200 and then taking the square root, the voltage effective value is 220.5 V; the timestamp of the 100th sampling point is 12345.5 ms, and the phase angle is calculated as:

[0145]

[0146] In one embodiment of the present application, the step S7 comprises the following steps:

[0147] The slave node transmits the simplified vector data to the analysis terminal, the fundamental effective value, the phase angle and the local timestamp are packaged into a simplified data packet, and are sent to the cloud or the local analysis terminal through the wireless network, for three-phase vector synthesis and power quality analysis.

[0148] Specifically, after the slave node completes the local vector parameter calculation in step S6, the obtained three core data of fundamental effective value, phase angle and local timestamp are combined into a transmission unit of fixed format, the transmission unit is packaged into a simplified data packet according to a predetermined protocol, and the simplified data packet is transmitted to the cloud server or the local analysis terminal through the sending queue of the wireless communication module.

[0149] The transmission process adopts a time division multiple access mechanism with collision avoidance, ensuring that no data collision occurs when multiple nodes work cooperatively. After the analysis terminal receives the data packets of the nodes, the voltage and current vector diagram is reconstructed based on the alignment of the time sequence according to the local timestamp, combined with the inherent phase relationship of the three phases, and the power calculation, unbalance degree analysis and other power quality evaluations are completed.

[0150] Among them, the fundamental effective value refers to the effective value of the voltage or current fundamental component calculated in step S6, representing the energy intensity characteristic of the phase in the power frequency cycle, and the numerical type is floating point. The local timestamp refers to the microsecond-level absolute time mark recorded by the local clock of the slave node, which has been synchronized with the predictor in step S5 through hardware compensation and calibration.

[0151] The phase angle refers to the angular offset of the local voltage or current of the phase relative to the starting point of the cycle calculated based on the compensated time reference in step S6, representing the position characteristic of the phase in the time dimension, and the numerical type is floating point.

[0152] The simplified data packet has a data structure containing three fixed fields: field 1 (4-byte floating point number) stores the fundamental effective value, field 2 (4-byte floating point number) stores the phase angle, and field 3 (4-byte integer) stores the local timestamp, with a total length of 12 bytes and no check bits.

[0153] The time division multiple access mechanism refers to the wireless transmission scheduling strategy, and each slave node sends data in a fixed time window. The position of the time window is determined by the last byte of the node MAC address and the time slot base value broadcast by the master node, and the sending time slot is The total number of time slots is determined by the master node broadcasting every 5 seconds, and the slave node assigns the time slot according to the last byte of the MAC address modulo 8.

[0154] Vector diagram reconstruction refers to the process of drawing the phase angle in the A, B and C three-phase data packets in polar coordinates in a unified circular coordinate system after subtracting 120° integer multiples, forming a rotating vector diagram.

[0155] For example, the B-phase slave node measures the voltage effective value 220.5V, the phase angle 8.98°, and the local timestamp 12345678000μs. It is encapsulated into a data packet: bytes 0-3 store 220.5 (hexadecimal 435C8000), bytes 4-7 store 8.98 (hexadecimal 410FAE14), and bytes 8-11 store 12345678000 (hexadecimal 02000000).

[0156] If the MAC last byte is 0xAB and the master node allocates the total time slot 256, the sending time slot is 171 (decimal of 0xAB). After analyzing the three-phase data received by the terminal: the A-phase phase angle 30.05° is directly plotted on the 0° reference test line, the B-phase phase angle 8.98° is plotted on the 120° position line (the actual display angle is 128.98°), and the C-phase phase angle -111.02° is plotted on the 240° position line (the actual display angle is 128.98°), an accurate three-phase vector diagram is generated.

[0157] Referring to the accompanying drawings, the application further provides a three-phase power parameter wireless synchronization measurement and vector analysis system, which comprises the following modules: Fig. 2 The master node phase synchronization module is used for acquiring the A-phase voltage waveform of the power grid, and when the phase tracking state reaches stability, a synchronization pulse code containing trigger phase information is generated and broadcasted at a predetermined accurate phase point;

[0158] The slave node signal processing module receives the synchronization pulse code and records the receiving timestamp, simultaneously acquires the local power grid frequency characteristics, and generates a predicted phase angle by running a local phase predictor;

[0159] The phase deviation calculation module calculates a theoretical expected phase angle based on the three-phase phase difference constraint and the trigger phase information, compares the theoretical expected phase angle with the predicted phase angle, and obtains a comprehensive phase deviation value;

[0160] The dynamic characteristic separation module performs dynamic characteristic separation processing on the comprehensive phase deviation value, generates a slowly-varying propagation delay characteristic caused by signal air propagation time, and a transient prediction error characteristic caused by local predictor drift;

[0161] The double-path calibration module calculates the equivalent propagation time according to the propagation delay characteristic and adjusts the local sampling time, and injects the prediction error characteristic into the local phase predictor for calibration;

[0162] The vector parameter calculation module is used for collecting the local voltage / current data based on the compensated sampling time, calculating the fundamental effective value, and calculating the phase angle relative to the local calibration time reference;

[0163]

[0164] ​Data transmission module, the fundamental wave effective value, phase angle and local timestamp are packaged as a simplified data packet and transmitted to the analysis terminal.

[0165] It should be noted that: the above formula, through the principle of dimensional consistency and mathematical standardization means (such as normalization processing, dimensionless parameter conversion or unit system unification), different properties of physical quantities can be translated into unitless standard values or same dimension superimposable parameters, so as to eliminate the interference of different dimensions on the operation logic, make the formula retain the original data distribution characteristics, and have mathematical operation rationality and objective law adaptability. The above is only an exemplary embodiment of the present application, and cannot limit the scope of the present application.

[0166] The various modules can be realized by software, hardware and their combination, support hardware form embedded in or independent of the processor in the computer device, and also support software form stored in the memory in the computer device, so as to facilitate the processor to call and execute the operation corresponding to each module.

[0167] It should be noted that the human information (including but not limited to human device information and personal information) and data (including but not limited to data for analysis, stored data and displayed data) involved in the present application are all information and data authorized by the human body or fully authorized by all parties. The collection, use and processing of related data require relevant legal standards.

[0168] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; these modifications or replacements do not change the essence of the corresponding technical solutions, and should be included in the protection scope of the present application.

Claims

1. A method for wireless synchronous measurement and vector analysis of three-phase power parameters, characterized in that, Includes the following steps: S1. Acquire the voltage waveform of phase A of the power grid. When the phase tracking state reaches a stable state, generate and broadcast a synchronization pulse code containing trigger phase information at a predetermined precise phase point. S2. Receive the synchronization pulse code and record the receiving timestamp, while obtaining the local power grid frequency characteristics and running the local phase predictor to generate the predicted phase angle. S3. Calculate the theoretically expected phase angle based on the three-phase phase difference constraint and trigger phase information, and compare it with the predicted phase angle to obtain the comprehensive phase deviation value; S4. Perform dynamic feature separation processing on the comprehensive phase deviation value to generate slowly varying propagation delay features caused by signal air propagation time, and transient prediction error features caused by local predictor drift. S5. Calculate the equivalent propagation time based on the propagation delay characteristics and adjust the local sampling time. At the same time, inject the prediction error characteristics into the local phase predictor for calibration. S6. Collect local phase voltage / current data based on the compensated sampling time, and calculate the fundamental effective value and the phase angle relative to the local calibration time reference; S7. Encapsulate the fundamental effective value, phase angle, and local timestamp into a simplified data packet and transmit it to the analysis terminal.

2. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, Generating and broadcasting a synchronization pulse code containing trigger phase information includes the following steps: The voltage waveform of phase A of the power grid is continuously monitored through a preset phase tracking device; When the maximum phase angle offset is less than a preset offset threshold for N consecutive cycles, the phase tracking state is determined to be stable. The predetermined precise phase point triggers the synchronization pulse generation unit, which encodes the current instantaneous phase angle to generate a synchronization pulse code.

3. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, Generating the predicted phase angle includes the following steps: The receive timestamp is latched during the receiving of the synchronization pulse encoding via a hardware interrupt mechanism; The zero-crossing point of this phase is detected by a local signal monitoring device, and the grid frequency characteristics are updated accordingly. The grid frequency characteristics are input to the local phase predictor, which generates a predicted phase angle sequence through incremental calculation and freezes the output value at the receiving timestamp.

4. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, To obtain the overall phase deviation value, the following steps are included: Based on the inherent three-phase phase difference constraint of the power grid, and combined with the master node triggering phase information in the synchronization pulse coding, the theoretical expected phase angle of this phase is calculated. The theoretically expected phase angle is directly compared with the predicted phase angle generated by the local phase predictor at the synchronization pulse reception timestamp, and the comprehensive phase deviation value is obtained by subtraction.

5. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, The dynamic feature separation process for the composite phase deviation value includes the following steps: The comprehensive phase deviation value is input into the dynamic feature separation processor; The slowly changing components in the overall phase deviation value are extracted by a first-order low-pass filter and identified as propagation delay features. After removing the slowly changing components by subtraction, the remaining high-frequency fluctuation components are identified as prediction error features. Based on the physical property that the propagation delay characteristics change slowly over time while the prediction error characteristics fluctuate rapidly, digital filtering technology is used to effectively separate the two types of features.

6. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, The prediction error characteristics are injected into the local phase predictor for calibration, including the following steps: The equivalent propagation time caused by the air transmission of radio signals is calculated based on the propagation delay characteristics and the local real-time measurement frequency. The prediction error characteristics are input into the proportional-integral regulator of the local phase predictor, and a phase correction is generated through proportional-integral operation. This correction is then added to the cumulative angle value of the local phase predictor in real time to suppress its inherent drift error.

7. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, Based on the compensated sampling time, the phase voltage / current data is acquired, and the fundamental RMS value and phase angle relative to the local calibration time reference are calculated, including the following steps: The analog-to-digital converter is triggered based on the adjusted sampling time to acquire the raw voltage / current data; The fundamental component is extracted using a digital bandpass filter; The fundamental frequency RMS value is calculated using a full-cycle integral algorithm. The phase angle is calculated based on the sampling time offset, using the current zero-crossing point as a reference.

8. The method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 1, characterized in that, The fundamental frequency RMS value, phase angle, and local timestamp are encapsulated into a simplified data packet and transmitted to the analysis terminal, including the following steps: The three core data points—fundamental effective value, phase angle, and local timestamp—are combined into a fixed-format transmission unit, which is then encapsulated into a simplified data packet according to a predetermined protocol. The transmission process employs a time-division multiple access mechanism with collision avoidance to ensure that no data collisions occur when multiple nodes work together. The voltage and current vector diagram is reconstructed by aligning the time series with the local timestamp and combining the inherent phase relationship of the three phases.

9. A method for wireless synchronous measurement and vector analysis of three-phase power parameters according to claim 8, characterized in that, The time-division multiple access mechanism includes the following steps: Each slave node sends data within a fixed time window; The time window position is determined by modulo operation between the last byte of the node's MAC address and the base value of the time slot broadcast by the master node. Transmission time slot = Total number of time slots.

10. A wireless synchronous measurement and vector analysis system for three-phase power parameters, characterized in that, Includes the following modules: The master node phase synchronization module is used to acquire the voltage waveform of phase A of the power grid. When the phase tracking state reaches a stable state, it generates and broadcasts a synchronization pulse code containing trigger phase information at a predetermined precise phase point. The node signal processing module receives the synchronization pulse code and records the receiving timestamp, while simultaneously acquiring the local grid frequency characteristics and running the local phase predictor to generate the predicted phase angle. The phase deviation calculation module calculates the theoretically expected phase angle based on the three-phase phase difference constraint and the trigger phase information, and compares it with the predicted phase angle to obtain the comprehensive phase deviation value. The dynamic feature separation module performs dynamic feature separation processing on the comprehensive phase deviation value to generate slowly varying propagation delay features caused by signal propagation time in the air, and transient prediction error features caused by local predictor drift. The dual-path calibration module calculates the equivalent propagation time based on the propagation delay characteristics and adjusts the local sampling time, while injecting the prediction error characteristics into the local phase predictor for calibration. The vector parameter calculation module is used to collect local phase voltage / current data based on the compensated sampling time, and calculate the fundamental effective value and the phase angle relative to the local calibration time reference. The data transmission module encapsulates the fundamental effective value, phase angle, and local timestamp into a simplified data packet and transmits it to the analysis terminal.

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