Low-power-consumption time synchronization method suitable for traveling wave positioning

Abstract

The invention relates to a low-power-consumption time synchronization method suitable for traveling wave positioning, and the method specifically comprises the following steps: firstly, in a traveling wave positioning device, no time synchronization operation is carried out at ordinary times; a global crystal oscillator counter is maintained in the device, and when a fault is detected, fault recording is carried out and a crystal oscillator counting value of a traveling wave data head is recorded; after fault recording is completed, the device performs time synchronization for the first time, and records a time value and a crystal oscillator count value after the first time synchronization; delaying the device for a period of time to carry out the second time synchronization, and recording the time value and the crystal oscillator count value after the two times of synchronization; and calculating a first data moment value of the traveling wave data and an actual sampling interval of the traveling wave data through the recorded data. And finally, completing accurate fault positioning according to a conventional wave head arrival time method. According to the invention, the frequency of time synchronization is reduced, so that the power consumption of the system is reduced; the method also has the characteristics of strong adaptability and easy implementation, and is suitable for various traveling wave positioning devices.

Description

Technical Field

[0001] The invention belongs to the technical field of power systems, and in particular relates to a low-power consumption time synchronization method suitable for traveling wave positioning. Background Art

[0002] In the power system, fault detection and location of distribution lines are crucial to ensure the reliability of power supply and the stability of the system. Traveling wave positioning technology relies on the characteristic that the speed of traveling waves is close to the speed of light, and determines the location of the fault point or target by measuring the propagation time of the traveling waves. However, this high-precision positioning requirement places extremely high demands on the accuracy of time synchronization, which usually requires an accuracy of 0.1 microsecond.

[0003] In the prior art, in order to meet this accuracy requirement, the system has to perform regular time synchronization operations with a time interval of seconds to ensure the accuracy of the positioning data. Due to the installation, the traveling wave positioning device can only be powered by electric field energy or solar energy. However, frequent time synchronization operations will cause the system power consumption to increase significantly, which greatly limits the practicality of the traveling wave positioning function and also limits the reliability and stability of the system. Especially in the wild or remote areas, when energy supply is limited, the problem of high power consumption is particularly prominent.

[0004] To address this challenge, the present invention proposes a low-power time synchronization method, which aims to significantly reduce the power consumption of the system while maintaining high-precision time synchronization. The core idea of ​​this method is to avoid any time synchronization operation during non-fault periods, thereby reducing the energy consumption of the system under normal operating conditions. The time synchronization process is only started after a fault is detected and the fault recording is completed to ensure the accuracy of the fault data. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and propose a low-power time synchronization method suitable for traveling wave positioning, aiming to solve the challenge of reducing system power consumption while maintaining high-precision time synchronization. In the traveling wave positioning system, since the speed of the traveling wave is close to the speed of light, the requirement for time synchronization accuracy is extremely high (reaching 0.1 microseconds). In order to meet this accuracy requirement, the prior art has to perform time synchronization operations frequently, resulting in a contradiction between limited energy supply of the device and excessive power consumption of the system. In response to this problem, the present invention proposes an optimized time synchronization strategy, which greatly reduces the frequency of time synchronization while ensuring the accuracy of time synchronization, thereby significantly reducing system power consumption.

[0006] The advantage of the low-power time synchronization method of the present invention is that it starts time synchronization only after a fault occurs and the recording is completed, which significantly reduces the frequency of time synchronization, thereby reducing the power consumption of the system; at the same time, the data obtained through multiple time synchronizations is used to accurately calculate the timestamp of the traveling wave data through the nonlinear least squares method, thereby avoiding timing errors caused by crystal oscillator deviations due to temperature changes, etc., and ensuring the accuracy of time synchronization; finally, the actual sampling interval of the traveling wave data is also sent to the traveling wave positioning master station, so that the traveling wave positioning master station can resample through cubic spline oversampling interpolation, unify the traveling wave waveforms of each device to the same target sampling rate, thereby completing a more accurate time difference calculation and ensuring the accuracy of traveling wave positioning. In addition, this method is also highly adaptable and easy to implement, and is suitable for various traveling wave positioning devices. In order to achieve the above object, the technical solution of the present invention is as follows: a low-power time synchronization method suitable for traveling wave positioning, the method comprising the following steps: Step 1: In the traveling wave positioning device, no time synchronization operation is usually performed to reduce system power consumption; Step 2: A global crystal oscillator counter is maintained in the device, and the resolution of the global crystal oscillator counter is not less than 10ns; Step 3: When a fault is detected, perform fault recording and record the crystal oscillator count value corresponding to the first data of the traveling wave data; Step 4: After completing the fault recording, the device shall perform time synchronization for no less than 2 times, and record the time value and crystal oscillator count value after each synchronization; the time interval between each 2 adjacent synchronizations shall be determined according to the travel time deviation of the crystal oscillator, and the empirical value shall be greater than 5 minutes, so as to accurately calculate the travel time deviation per unit time in the device.

[0007] Step 5: According to the recorded count value of the first data of the traveling wave, the moment of each time synchronization and the count value of the crystal oscillator, the change trend of the crystal oscillator count value is predicted by the nonlinear least square method, and the moment of the first data of the traveling wave and the actual sampling interval of the traveling wave data are calculated; (1) Assume that the number of time synchronizations is , No. The time value and crystal oscillator count value recorded in the second synchronization are and ; (2) Calculate the fitting coefficients based on the nonlinear least squares method , , , , , , in, is the time average, is the average value of the crystal oscillator counts, , is the fitting coefficient of the time series relationship between the crystal oscillator count value and the timestamp, (3) Calculate the first data moment of the traveling wave: , in is the crystal oscillator count value of the traveling wave head (4) The fitting coefficients As the actual sampling interval, Step 6: Synchronously send the traveling wave waveform data, the first data time of the traveling wave and the actual sampling interval of the device to the traveling wave positioning master station; Step 7: After the traveling wave positioning master station receives the traveling wave waveform data, the first data time of the traveling wave and the sampling interval of the traveling wave waveform, it first uses cubic spline oversampling interpolation to perform traveling wave data; then resamples according to the target sampling rate to obtain the traveling wave waveform data for final positioning; The target frequency of the cubic spline oversampling is not less than 100 MHz, and the process is as follows: Construct a cubic spline: For every four consecutive data points of the original data, construct a cubic spline polynomial , ensuring that the spline is continuous at the data points and continuous in the second-order derivative. The data points are represented as , , The coefficient is calculated as follows: , , , , , in is the difference between adjacent data points, , , , are the coefficients of the cubic spline polynomial respectively; The interpolated sampling points are located between the original data points according to the target oversampling frequency. For , New sampling points between original data points , using a cubic spline polynomial Calculate interpolation , in is the data after oversampling interpolation, is the position of the new sampling point, , , , are the coefficients of the cubic spline polynomial respectively; All calculated interpolation points , combined into new oversampled data.

[0008] Step 8: The traveling wave positioning master station uses the conventional wave head arrival time method to complete accurate fault location based on the resampled traveling wave waveform data.

[0009] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the low-power time synchronization method suitable for traveling wave positioning is implemented.

[0010] Compared with the prior art, the present invention has the following significant advantages: 1. This solution significantly reduces system power consumption: Compared with the frequent timed synchronization of traditional devices, the present invention does not perform any time synchronization operation during non-fault periods, which greatly reduces the energy consumption of the system under normal operation. This design makes the traveling wave positioning device in a low-power state most of the time, and the time synchronization process is only started after a fault is detected and the fault recording is completed. This strategy effectively balances the need for time synchronization and system power consumption, making the entire system more energy-efficient; 2. The scheme maintains high-precision time synchronization: Although the frequency of time synchronization is reduced, the present invention can accurately calculate the current crystal oscillator period through the data obtained through multiple time synchronizations and the nonlinear least squares method, thereby ensuring the accuracy of time synchronization. This strategy not only avoids the crystal oscillator deviation caused by temperature changes, etc., but also ensures the accuracy of traveling wave positioning by accurately calculating the first data moment of the traveling wave and the actual sampling interval; 3. This solution improves the accuracy of fault location: The present invention also sends the actual sampling interval to the traveling wave positioning master station. The traveling wave positioning master station reconstructs the traveling wave waveform through cubic spline oversampling interpolation, and then resamples it into traveling wave data at the target sampling rate according to the target sampling rate. This solves the error caused by the crystal oscillator deviation between different traveling wave positioning devices and improves the accuracy of fault location. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0013] The following descriptions of the embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention may be implemented.

[0014] Example: Figure 1 A low-power time synchronization method suitable for traveling wave positioning is shown, and the method comprises the following steps: (1) In the traveling wave positioning device, no time synchronization operation is usually performed to reduce system power consumption; (2) A global crystal oscillator counter is maintained in the device, and the resolution of the global crystal oscillator counter is not less than 10ns; (3) When a fault is detected, perform fault recording and record the crystal oscillator count value corresponding to the first data of the traveling wave data; (4) After completing the fault recording, the device shall perform time synchronization for no less than 2 times, and record the time value and crystal oscillator count value after each synchronization; the time interval between each two adjacent synchronizations shall be determined according to the travel time deviation of the crystal oscillator, and the empirical value shall be greater than 5 minutes, so as to accurately calculate the travel time deviation per unit time in the device. (5) Based on the recorded count value of the first data of the traveling wave, the moment of each time synchronization and the crystal oscillator count value, the nonlinear least squares method is used to predict the change trend of the crystal oscillator count value, and the moment of the first data of the traveling wave and the actual sampling interval of the traveling wave data are calculated; Assume that the number of time synchronizations is , No. The time value and crystal oscillator count value recorded in the second synchronization are and ; Calculate the fitting coefficients according to the nonlinear least squares method , , , , , , in, is the time average, is the average value of the crystal oscillator counts, , is the fitting coefficient of the time series relationship between the crystal oscillator count value and the timestamp, Calculate the first data moment of the traveling wave: , in is the crystal oscillator count value of the traveling wave head The fitting coefficients As the actual sampling interval, (6) Synchronously send the traveling wave waveform data, the first data time of the traveling wave, and the actual sampling interval of the device to the traveling wave positioning master station; (7) After the traveling wave positioning master station receives the traveling wave waveform data, the first data time of the traveling wave and the sampling interval of the traveling wave waveform, it first uses cubic spline oversampling interpolation to interpolate the traveling wave data, and then resamples it according to the target sampling rate (not less than 10MHz) to obtain the traveling wave waveform data for final positioning.

[0015] The target frequency of the cubic spline oversampling is not less than 100 MHz, and the process is as follows: Construct a cubic spline: For every four consecutive data points of the original data, construct a cubic spline polynomial , ensuring that the spline is continuous at the data points and continuous in the second-order derivative. The data points are represented as , , The coefficient is calculated as follows: , , , , , in is the difference between adjacent data points, , , , are the coefficients of the cubic spline polynomial respectively; The interpolation sampling points are determined according to the target oversampling frequency, and these points are located between the original data points. For , New sampling points between original data points , using a cubic spline polynomial Calculate interpolation , in is the data after oversampling interpolation, is the position of the new sampling point, , , , are the coefficients of the cubic spline polynomial respectively; All calculated interpolation points , combined into new oversampled data, (8) The traveling wave positioning master station uses the conventional wave head arrival time method to accurately locate the fault based on the resampled traveling wave waveform data.

[0016] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above technical features.

Claims

1. A low-power time synchronization method suitable for traveling wave positioning, characterized in that: The method comprises the following steps: Step 1: In the traveling wave positioning device, no time synchronization operation is usually performed to reduce system power consumption. Step 2: Maintain a global crystal counter in the device. Step 3: When a fault is detected, perform fault recording and record the crystal oscillator count value corresponding to the first data of the traveling wave data. Step 4: After completing the fault recording, the device performs time synchronization for no less than 2 times, and records the time value and crystal oscillator count value after each synchronization; Step 5: According to the recorded count value of the first data of the traveling wave, the moment of each time synchronization and the count value of the crystal oscillator, the change trend of the crystal oscillator count value is predicted by the nonlinear least square method, and the moment of the first data of the traveling wave and the actual sampling interval of the traveling wave data are calculated. Step 6: Synchronously send the traveling wave waveform data, the first data time of the traveling wave and the actual sampling interval of the device to the traveling wave positioning master station. Step 7: The traveling wave positioning master station first uses cubic spline oversampling interpolation to the traveling wave data according to each traveling wave waveform moment and the actual sampling interval of the traveling wave data, and then resamples it according to the target sampling rate to obtain the traveling wave waveform data for final positioning. Step 8: The traveling wave positioning master station uses the conventional wave head arrival time method to complete accurate fault location based on the resampled traveling wave waveform data.

2. A low-power time synchronization method suitable for traveling wave positioning as claimed in claim 1, characterized in that: The resolution of the global crystal oscillator counter is not less than 10ns to ensure the accuracy of time synchronization.

3. A low-power time synchronization method suitable for traveling wave positioning as claimed in claim 1, characterized in that: After completing the fault recording, the device shall perform time synchronization no less than 2 times; the time interval between each two adjacent synchronizations is determined according to the timing deviation of the crystal oscillator, and the empirical value is greater than 5 minutes, so as to accurately calculate the timing deviation per unit time in the device.

4. A low-power time synchronization method suitable for traveling wave positioning as claimed in claim 1, characterized in that: The method of calculating the time of the traveling wave head and the actual sampling interval of the traveling wave data by the nonlinear least squares method is: (1) Assume that the number of time synchronizations is , No. The time value and crystal oscillator count value recorded in the second synchronization are and ; (2) Calculate the fitting coefficients based on the nonlinear least squares method , , ， ， ， ， in, is the time average, is the average value of the crystal oscillator counts, , is the fitting coefficient of the time series relationship between the crystal oscillator count value and the timestamp, (3) Calculate the first data moment of the traveling wave: ， in is the crystal oscillator count value of the traveling wave head (4) The fitting coefficients as the actual sampling interval.

5. A low-power time synchronization method suitable for traveling wave positioning as claimed in claim 1, characterized in that: After receiving the traveling wave waveform data, the first data time of the traveling wave and the sampling interval of the traveling wave waveform, the traveling wave data is first oversampled and interpolated using cubic spline, and then resampled according to the target sampling rate; and the reconstructed traveling wave data is used for fault location. The target frequency of the cubic spline oversampling is not less than 100 MHz, and the process is as follows: Construct a cubic spline: For every four consecutive data points of the original data, construct a cubic spline polynomial , ensuring that the spline is continuous at the data points and continuous in the second-order derivative. The data points are represented as , ， The coefficient is calculated as follows: ， ， ， ， ， in is the difference between adjacent data points, , , , are the coefficients of the cubic spline polynomial, The interpolated sampling points are located between the original data points according to the target oversampling frequency. For , New sampling points between original data points , using a cubic spline polynomial Calculate interpolation ， in is the data after oversampling interpolation, is the position of the new sampling point, , , , are the coefficients of the cubic spline polynomial respectively; All calculated interpolation points , combined into new oversampled data.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, a low-power time synchronization method suitable for traveling wave positioning as described in any one of claims 1 to 5 is implemented.

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