Wide-area synchronous power distribution monitoring system and working method thereof

Abstract

The invention provides a wide-area synchronous power distribution monitoring system and a working method thereof, and relates to the technical field of power distribution monitoring. The method comprises the following steps: a high-speed sampling ADC unit circuit of the synchronous power distribution terminal samples voltage and current data of a power distribution network according to a set sampling frequency; the voltage and current data of the power distribution network collected by each synchronous power distribution terminal are sent to a server through a 4G / 5G network, and the server monitors the received data in real time and judges a current abrupt change fault and a voltage amplitude abnormity; and if a fault occurs, the server collects synchronous sampling data of the plurality of synchronous power distribution terminals before and after the fault occurs, analyzes characteristics including fault current flow direction and phase change, and adopts a fault positioning algorithm model to determine a line section where the fault position is located to perform fault positioning. According to the invention, the monitoring data of the power distribution terminals at different positions can be accurately synchronized in time, and the fault type can be quickly positioned and the position of the fault point can be accurately calculated through the preset fault judgment logic.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution monitoring, and in particular to a wide-area synchronous power distribution monitoring system and a working method thereof. Background Art

[0002] In modern power systems, the stable operation and efficient management of distribution networks are crucial to ensuring the normal power consumption of social production and life. With the continuous growth of power demand, the widespread access of distributed energy and the advancement of smart grid construction, higher requirements are placed on the monitoring, control and management of distribution systems.

[0003] Traditional power distribution monitoring methods have gradually exposed many limitations in the face of increasingly complex power distribution environments. On the one hand, in terms of synchronous measurement, traditional equipment is difficult to achieve high-precision synchronous sampling in a wide area, resulting in the inability to effectively integrate and analyze measurement data at different locations, which brings great difficulties to accurately assessing the operating status of the distribution system, locating fault points, and analyzing power quality issues. For example, in a power distribution network in a large area, due to the lack of precise synchronization, when a fault occurs, the data from each monitoring point cannot accurately reflect the change relationship of the electrical quantity at the moment of the fault, so that fault location often requires a lot of time and manpower for troubleshooting, which prolongs the power outage time and reduces the reliability of power supply.

[0004] On the other hand, the functions of traditional power distribution terminals are relatively simple. In terms of power supply methods, most of them rely on only a single power supply mode. When the operating conditions of the distribution lines are complex and changeable (such as voltage fluctuations, power outages, etc.), the stability of power supply cannot be guaranteed, affecting the continuous operation of terminal equipment, which may lead to missing or incomplete monitoring data. At the same time, traditional terminals are unable to cope with new demands such as possible power theft and the need to interact with peripheral equipment for more comprehensive system monitoring and management. For example, in terms of anti-power theft, there is a lack of effective monitoring means and intelligent judgment methods, making it difficult to quickly and accurately identify complex and diverse power theft behaviors.

[0005] In addition, with the continuous expansion of the scale of the distribution network and the increasing complexity of its structure, traditional management models and technical means have been unable to meet the needs of refined management and optimized operation of the entire distribution system. An innovative technology and equipment is urgently needed to solve these problems, realize comprehensive monitoring of distribution lines, rapid fault handling, reliable power supply and multi-functional integration, so as to improve the intelligence level and operational reliability of the distribution system and meet the requirements of the development of modern power systems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a wide-area synchronous power distribution monitoring system and a working method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0007] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0008] A wide-area synchronous power distribution monitoring system, comprising: a plurality of synchronous power distribution terminals arranged in a distribution network, the plurality of synchronous power distribution terminals being wirelessly connected to a 4G / 5G base station, the 4G / 5G base station being wirelessly connected to a server, the server being wirelessly connected to a mobile monitoring terminal and a large monitoring screen;

[0009] The synchronous power distribution terminal comprises an A-phase unit, a B-phase unit and a C-phase unit, wherein the B-phase unit is a main unit and the A-phase unit and the C-phase unit are auxiliary units;

[0010] The A-phase unit and the C-phase unit respectively include an electronic current transformer, an electronic voltage transformer, a high-voltage power supply capacitor and a power supply transformer, wherein the A-phase unit electronic voltage transformer and the C-phase unit electronic voltage transformer are respectively connected between the AB phase and between the BC phase;

[0011] The B-phase unit includes an electronic current transformer, a power supply module, a power supply group, a high-speed ADC sampling circuit, a processor circuit, a 4G module, an encryption chip, a Bluetooth circuit, a clock circuit, a Beidou timing circuit, a first storage chip, a second storage chip, and a battery. The processor circuit is electrically connected to the power supply group, the high-speed ADC sampling circuit, the 4G module, the encryption chip, the Bluetooth circuit, the clock circuit, the Beidou timing circuit, the first storage chip, the second storage chip, and the battery. The power supply group is electrically connected to the power supply module.

[0012] The power taking module is electrically connected to the power taking transformers of the A phase unit and the C phase unit, and the high-speed ADC sampling circuit is electrically connected to the electronic voltage transformers of the A phase unit and the C phase unit and the electronic current transformers of the A phase unit, the B phase unit and the C phase unit.

[0013] Optionally, the electronic current transformers of the A-phase unit, the B-phase unit and the C-phase unit all adopt a secondary current mutual inductance structure.

[0014] Optionally, the power supply module is electrically connected to the secondary of the A-phase power supply transformer corresponding to the A-phase unit and the C-phase power supply transformer corresponding to the C-phase unit, and the primary of the A-phase power supply transformer and the C-phase power supply transformer are respectively connected to the A-phase power line and the C-phase power line through corresponding high-voltage power supply capacitors.

[0015] Optionally, the electronic voltage transformer input terminals of the A-phase unit and the C-phase unit are connected to the A-phase power line and the C-phase power line respectively through a high-voltage capacitor voltage divider circuit.

[0016] Optionally, the power supply module includes an electrical connection with a supercapacitor, and the power supply module includes a rectifier and filter sub-module, a DC-DC sub-module, a control sub-module, and a protection sub-module. The rectifier and filter sub-module, the DC-DC sub-module, the protection sub-module are electrically connected to the control sub-module, and the input end of the rectifier and filter sub-module is electrically connected to the secondary of the power supply transformer.

[0017] Optionally, insulating epoxy resin is poured between the coil and the magnetic core of the secondary current mutual inductance structure of the electronic current transformer for voltage-resistant isolation.

[0018] The present invention also provides a working method of a wide-area synchronous power distribution monitoring system, comprising the following steps:

[0019] The high-speed sampling ADC unit circuit of the synchronous power distribution terminal samples the voltage and current data of the distribution network according to the set sampling frequency; the voltage and current data include the A, B, and C phase currents I of the A phase unit, B phase unit, and C phase unit measured and detected by the electronic current transformer. A ,I B ,I C , and the AB phase and BC phase line voltage U of the A phase unit and the C phase unit detected by the electronic voltage transformer relative to the B phase AB , U BC ;

[0020] The voltage and current data of the distribution network collected by each synchronous distribution terminal are sent to the server via the 4G / 5G network. The server monitors the received data in real time to judge the current mutation fault and the voltage amplitude abnormality.

[0021] If a fault occurs, the server collects synchronous sampling data from multiple synchronous distribution terminals before and after the fault occurs, analyzes the characteristics of not limited to the fault current flow direction and phase change, and uses the fault location algorithm model to determine the line section where the fault is located for fault location.

[0022] Optionally, it also includes using an electricity theft judgment algorithm to determine whether there is electricity theft, and the electricity theft judgment algorithm includes calculating the power comparison factor Δ p , current and voltage phase relationship factor Δ θ , current voltage mutation factor Δ a , for power contrast factor Δ p , current and voltage phase relationship factor Δ θ , current voltage mutation factor Δ a Normalize and factor the normalized Assign weights K1, K2, and K3 respectively and calculate the judgment criteria for electricity theft , when Δ S Exceeding the preset threshold , determining that electricity theft occurred.

[0023] Optionally, the determination of a current mutation fault or a voltage amplitude abnormality is specifically as follows:

[0024] For current mutation detection, assume that the average current value during normal operation is , standard deviation is σ, k is the correction coefficient, and the current mutation threshold is When the current value I is detected to meet And the duration exceeds the set time t th When , it is judged as a current mutation fault;

[0025] For voltage amplitude abnormality detection, the voltage rating is assumed to be U r , the allowable fluctuation range is ±ΔU, when the voltage value U satisfies U<U r (1-ΔU) or U>U r (1+ΔU), it is judged as abnormal voltage amplitude fault; three-phase unbalance When ε>ε th When , it is judged as a three-phase unbalanced fault.

[0026] Optionally, the fault location algorithm model is used to determine the line segment where the fault location is located for fault location. Specifically, a fault location algorithm based on the traveling wave principle is used. Assume that the distance from the fault point to the monitoring point 1 is x, the propagation speed of the traveling wave on the transmission line is υ, the time of fault occurrence is t0, the time when the monitoring point 1 detects the first arrival of the fault traveling wave is t1, and the time when the monitoring point 2 detects the first arrival of the fault traveling wave is t2. Then the position of the fault point is L is the line inductance per unit length, and C is the line capacitance per unit length.

[0027] The beneficial effects of the above technical solution of the present invention are as follows:

[0028] 1. The present invention is based on the high-precision wide-area synchronous sampling technology of the Beidou timing module to ensure that the monitoring data of the distribution terminals at different locations are accurately synchronized in time with minimal error. Whether it is the power quality assessment under normal operating conditions or the analysis of electrical quantity changes when a fault occurs, accurate and synchronous information can be obtained, greatly improving the reliability of the monitoring results.

[0029] 2. The fast fault alarm function provided by the present invention can detect abnormalities in time at the moment of fault occurrence, and can quickly locate the fault type through the preset fault judgment logic. The wide-area synchronous fault location method based on the traveling wave principle uses transient waveform data provided by multiple terminals, combined with precise time synchronization, to accurately calculate the location of the fault point. This greatly shortens the troubleshooting and repair time, reduces the scope of power outages, effectively improves power supply reliability, ensures normal power supply for users, and reduces economic losses and social impacts caused by power outages.

[0030] 3. The present invention integrates multiple functions such as line monitoring, power extraction, anti-power theft, data collection and upload, and peripheral equipment data interaction, which reduces the number and types of equipment required in the power distribution system and simplifies the system architecture and management process.

[0031] 4. The present invention adopts the dual isolation technology of current transformer to ensure safe and reliable measurement under 10KV high voltage environment. The dual-line voltage power supply technology enables the terminal to obtain power stably under different line conditions (such as voltage fluctuations, power outages, etc.), ensuring the continuous operation of key functions of the terminal, extending the service life of the equipment, and improving the reliability and availability of the equipment in complex power distribution environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the overall principle block diagram of the wide area synchronous power distribution monitoring system of the present invention;

[0033] Figure 2 This is a principle block diagram of the synchronous power distribution terminal of the present invention;

[0034] Figure 3 It is a flow chart of the working method of the wide area synchronous power distribution monitoring system of the present invention. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] like Figure 1 As shown, the present invention proposes a wide-area synchronous power distribution monitoring system, including: a plurality of synchronous power distribution terminals arranged in the distribution network, the plurality of synchronous power distribution terminals are wirelessly connected to a 4G / 5G base station, the 4G / 5G base station is wirelessly connected to a server, and the server is wirelessly connected to a mobile monitoring terminal and a large monitoring screen through a network.

[0038] like Figure 2 As shown, the synchronous power distribution terminal includes an A-phase unit, a B-phase unit, and a C-phase unit, wherein the B-phase unit is a main unit, and the A-phase unit and the C-phase unit are auxiliary units;

[0039] The A-phase unit and the C-phase unit respectively include an electronic current transformer, an electronic voltage transformer, a high-voltage power supply capacitor and a power supply transformer, wherein the A-phase unit electronic voltage transformer and the C-phase unit electronic voltage transformer are respectively connected between the AB phase and between the BC phase;

[0040] The B-phase unit includes an electronic current transformer, a power supply module, a power supply group, a high-speed ADC sampling circuit, a processor circuit, a 4G module, an encryption chip, a Bluetooth circuit, a clock circuit, a Beidou timing circuit, a first storage chip, a second storage chip, and a battery. The processor circuit is electrically connected to the power supply group, the high-speed ADC sampling circuit, the 4G module, the encryption chip, the Bluetooth circuit, the clock circuit, the Beidou timing circuit, the first storage chip, the second storage chip, and the battery. The power supply group is electrically connected to the power supply module.

[0041] The power taking module is electrically connected to the power taking transformers of the A phase unit and the C phase unit, and the high-speed ADC sampling circuit is electrically connected to the electronic voltage transformers of the A phase unit and the C phase unit and the electronic current transformers of the A phase unit, the B phase unit and the C phase unit.

[0042] In this embodiment, the electronic current transformers of the A-phase unit, the B-phase unit and the C-phase unit all adopt a secondary current mutual inductance structure.

[0043] In this embodiment, the power supply module is electrically connected to the secondary of the A-phase power supply transformer corresponding to the A-phase unit and the C-phase power supply transformer corresponding to the C-phase unit. The primary of the A-phase power supply transformer and the C-phase power supply transformer are respectively connected to the A-phase power line and the C-phase power line through corresponding high-voltage power supply capacitors.

[0044] In this embodiment, the input terminals of the electronic voltage transformers of the A-phase unit and the C-phase unit are connected to the A-phase power line and the C-phase power line respectively through high-voltage capacitor voltage divider circuits.

[0045] In this embodiment, the power taking module includes an electrical connection with the supercapacitor, and the power taking module includes a rectifier and filter sub-module, a DC-DC sub-module, a control sub-module, and a protection sub-module. The rectifier and filter sub-module, the DC-DC sub-module, the protection sub-module are electrically connected to the control sub-module, and the input end of the rectifier and filter sub-module is electrically connected to the secondary of the power taking transformer.

[0046] In this embodiment, the coil and the magnetic core of the secondary current mutual inductance structure of the electronic current transformer are filled with insulating epoxy resin for voltage isolation. Specifically, the first-level current measurement coil and the magnetic core are filled with epoxy resin with excellent insulation performance, which can withstand a voltage of 48KV, and the second-level small current transformer is also an electronic current transformer filled with epoxy resin, ensuring safe and reliable measurement in a 10KV high-voltage environment.

[0047] When the system is implemented, the terminal body is hung on the middle phase (the middle phase of the line is phase B by default), and the two arms of the body are respectively hung on the two side phases (the two side phases are phase A and phase C by default). There are electronic current transformers on the three-phase lines. The current transformers are isolated at two levels and can work reliably on 10KV lines. They are used to measure the three-phase phase (line) current I A ,IB ,I C .

[0048] Both the side phases and the middle phase are connected to an electronic voltage transformer with high-voltage capacitor voltage division, which is used to measure the voltage U between the two side phases and the middle phase. AB , U BC , both sides of the phase are connected to the middle phase of the high-voltage capacitor to divide the voltage and match the appropriate power transformer to draw power. After the dual transformer draws power, it is combined to supply power to the terminal after rectification and filtering, and charges the battery at the same time. The backup super capacity of the power supply circuit provides short-term power support when the external power is abnormal, ensuring the continuous operation of the terminal's key functions, improving the reliability and stability of power supply, and adapting to different working conditions of the distribution line.

[0049] Voltage conversion formula during power extraction: Assume that the high-voltage side line voltage is U L , the voltage after the high voltage capacitor divides the voltage is U d , the power transformer ratio is n, then the voltage U after the power transformer t for The DC voltage after rectification and filtering is U dc It can be calculated by the corresponding formula according to the type of rectifier circuit (such as half-wave rectification, full-wave rectification or bridge rectification) and the size of the filter capacitor. In general, the DC voltage after full-wave rectification and simple filtering is approximately U dc ≈1.2×U t (Ignore factors such as diode voltage drop). The total supply voltage after the two-way power supply is combined is the sum of the two DC voltages, that is, U total =U dc1 +U dc2 .

[0050] This terminal can measure 3 phase currents and 2 line voltages on a circuit board at the same time. The sampling is guided by the second pulse of the Beidou timing module for system synchronous sampling (settable within 51.2KSPS), and there is no cumulative error of more than one second. Different terminal data can be synchronously analyzed for waveform data. The sampling is based on the second pulse of the Beidou timing module with an absolute time accuracy of 20nS. According to the second pulse, the phase-locked frequency multiplication technology is used. The sampling frequency can be set arbitrarily within the 51.2KSPS sampling range. The terminal can correct the system clock error based on the absolute time second pulse count. The terminal stores test data according to the preset sampling frequency with the second pulse as a reference for processing data waveform data and fault judgment. Multiple terminals hung on different lines can realize fault alarm and positioning under wide area synchronization.

[0051] In a monitoring system composed of multiple terminals, each terminal provides transient waveform data. The master station collects and integrates the synchronous sampling data of each terminal, analyzes the characteristics of fault current flow direction, phase change, etc., and combines a specific fault location algorithm model to determine the line section where the fault location is located, thereby achieving accurate fault location under wide area synchronization.

[0052] The system works like this:

[0053] First, carefully hang the terminal body on the middle phase (Phase B) of the 10KV distribution line to ensure that it is firmly installed. Then connect the two arms to the two side phases (Phase A and Phase C) respectively, so that the electronic current transformer and voltage transformer on the three-phase line are correctly connected to the circuit, and check whether the high-voltage power supply capacitor and power supply transformer of the power supply part are connected reliably. After the system is powered on, the high-stability clock circuit starts to work, and the timing circuit receives the second pulse signal of the Beidou timing module, initializes and calibrates the terminal system clock, and ensures the time accuracy of subsequent sampling and data processing.

[0054] The timing module continuously receives Beidou satellite signals to obtain high-precision second pulses. The terminal uses phase-locked frequency multiplication technology to set the sampling frequency within the range of 51.2KSPS according to actual monitoring needs. For example, when monitoring normal operation, it can be set to 10KSPS; when performing fault analysis or power quality monitoring, the sampling frequency can be increased to 51.2KSPS. Under the control of the processor circuit, the high-speed ADC sampling circuit synchronously samples the three-phase current and the line voltage on both sides according to the set sampling frequency. During the sampling process, the terminal continuously corrects the system clock error based on the count of second pulses to ensure the time synchronization of each sampling point. The sampled data is preliminarily processed by the processor circuit, such as filtering, calculating the effective value and phase of the electrical quantity, etc. The processed data is stored in the storage chip together with the time tag for subsequent fault judgment, waveform analysis and data upload.

[0055] The processor circuit monitors the sampled data in the storage chip in real time and analyzes it according to the preset fault judgment logic. For example, when it is detected that a phase current suddenly changes in a short period of time and exceeds the set threshold, and the duration reaches a certain length of time, it is judged that a short circuit fault may occur; when the voltage amplitude exceeds the normal range or the three-phase imbalance exceeds the allowable value, it is judged as an abnormal voltage fault. In a monitoring system composed of multiple terminals, each terminal uploads the synchronous sampling data to the main station through a 4G module. The main station collects and integrates the data of each terminal, and compares and analyzes the transient waveforms collected by each terminal at the same time. According to the propagation characteristics of the fault characteristics in the power grid, such as the attenuation of the fault current from the fault point to both ends, the phase change law, etc., the line segment where the fault location is located is determined through calculation and algorithm models, and fault location under wide area synchronization is achieved.

[0056] The high-voltage capacitor voltage-dividing power-taking circuit on both sides (phase A and phase C) steps down the 10KV line voltage, converts it into a suitable voltage through the power-taking transformer, and then converts the AC power into DC power through the rectifier and filter circuit. The DC power after the dual-circuit power is combined to power the various components of the terminal and charge the battery at the same time. The backup supercapacitor equipped in the power supply circuit can temporarily maintain the operation of key components of the terminal (such as processor circuits, storage chips, communication modules, etc.) when the external power supply is abnormal (such as line power outage or power supply equipment failure), ensuring that the terminal can complete operations such as important data storage and fault alarm information upload to prevent data loss.

[0057] The processor circuit continuously analyzes the sampled current, voltage and power data, and makes judgments based on historical data and the preset electricity theft judgment algorithm model. For example, by comparing the real-time power with the theoretical power, analyzing whether the current and voltage phase relationship is abnormal, and detecting whether there is a sudden change in current or voltage without a corresponding power change, it is determined whether there is electricity theft. When suspected electricity theft is detected, the terminal immediately triggers the anti-electricity theft alarm, and uploads the alarm information to the background management system through the 4G module. At the same time, it can communicate with the local inspection equipment through the Bluetooth circuit, which is convenient for on-site staff to obtain the alarm information in time and conduct investigation and processing.

[0058] The terminal establishes a connection with peripheral devices (such as environmental sensors, other intelligent monitoring devices, etc.) through Bluetooth circuits or other extended communication interfaces, and regularly collects data collected by peripheral devices, such as ambient temperature, humidity, and electromagnetic field strength around the line. The collected peripheral device data is integrated with the distribution line data collected by itself, such as analyzing the impact of environmental factors on line electrical parameters, or judging whether there is an external interference source based on changes in the surrounding electromagnetic field. The processed data is uploaded to the background system through the 4G module together with its own monitoring data, providing more comprehensive information for the comprehensive management and operation optimization of the distribution system.

[0059] The terminal uploads the collected and processed monitoring data, fault alarm information, anti-electricity theft detection results, and peripheral equipment data to the server backend management system through the 4G module according to the set time interval or event trigger (such as fault occurrence, data anomaly, etc.). The server backend management system can remotely configure and manage the terminal, such as remotely setting the sampling frequency, adjusting the fault alarm threshold, and updating the electricity theft judgment algorithm. At the same time, the server backend management system can conduct in-depth analysis of the uploaded data, generate reports and draw waveforms through the monitoring screen, provide decision support for operation and maintenance personnel, and realize intelligent remote monitoring and management of 10KV distribution lines.

[0060] Example 2

[0061] like Figure 3As shown, the present invention also proposes a working method of a wide-area synchronous power distribution monitoring system, comprising the following steps:

[0062] S1. The high-speed sampling ADC unit circuit of the synchronous distribution terminal samples the voltage and current data of the distribution network according to the set sampling frequency; the voltage and current data include the A, B, and C phase currents I of the A phase unit, the B phase unit, and the C phase unit measured and detected by the electronic current transformer. A ,I B ,I C , and the AB phase and BC phase line voltage U of the A phase unit and the C phase unit detected by the electronic voltage transformer relative to the B phase AB , U BC ;

[0063] S2. The voltage and current data of the distribution network collected by each synchronous distribution terminal are sent to the server via the 4G / 5G network. The server monitors the received data in real time to determine the current mutation fault and voltage amplitude abnormality;

[0064] S3. If a fault occurs, the server collects synchronous sampling data from multiple synchronous distribution terminals before and after the fault occurs, analyzes the characteristics of the fault current flow direction and phase change, and uses the fault location algorithm model to determine the line section where the fault is located for fault location.

[0065] In this embodiment, it is also included to determine whether there is electricity theft using an electricity theft determination algorithm, and the electricity theft determination algorithm includes calculating the power comparison factor Δ p , current and voltage phase relationship factor Δ θ , current voltage mutation factor Δ a , for power contrast factor Δ p , current and voltage phase relationship factor Δ θ , current voltage mutation factor Δ a Normalize and factor the normalized Assign weights K1, K2, and K3 respectively and calculate the judgment criteria for electricity theft When Δ S Exceeding the preset threshold It is determined that electricity theft has occurred.

[0066] (1) The power contrast factor calculation method is:

[0067] Based on the collected voltage and current data, combined with the load characteristics of the distribution line (such as resistance, inductance, power factor and other parameters), the theoretical power P that the line should consume under normal circumstances is calculated. 理论 For example, for a purely resistive load, P 理论 =U×I (U is the voltage RMS value, I is the current RMS value); for inductive or capacitive loads, ( is the power factor).

[0068] Real-time power monitoring: The synchronous power distribution terminal continuously calculates the actual power P 实际 , obtained by multiplying and integrating the sampled voltage and current data. 理论 With P 实际 The absolute value of the difference (i.e., the power contrast factor Δ p ) exceeds the set threshold, there may be electricity theft. For example, if the actual power is much lower than the theoretical power and lasts for a period of time, there may be electricity theft, resulting in inaccurate energy measurement.

[0069] (2) The calculation method of the current and voltage phase relationship factor is:

[0070] Under normal circumstances, the phase relationship between voltage and current is relatively stable, depending on the nature of the load (inductive, capacitive or resistive). The synchronous distribution terminal calculates the phase difference Δ between voltage and current by analyzing the sampled data. θ For example, for inductive loads, the current lags behind the voltage by a certain angle; for capacitive loads, the current leads the voltage by a certain angle. If an abnormal change in the phase difference is detected, such as a sudden change or exceeding the normal range, it may be due to the fact that the power theft device has changed the electrical characteristics of the line, thus judging that power theft may exist.

[0071] (3) The calculation method of current and voltage mutation factor is:

[0072] The synchronous power distribution terminal monitors the changes of current and voltage in real time. When a sudden and large change in current or voltage is detected (such as exceeding the set multiple of the normal fluctuation range), and this change has no reasonable power system operation reason (such as the start of large equipment, etc.), and there is no corresponding normal change in power, it may be caused by the connection or operation of the power theft device. For example, by setting the current mutation threshold (such as determined according to the statistical characteristics of the normal operating current), when |II p |>I th And the duration exceeds the set time t th When (I is the current current value, I p If the current value at the previous moment lasts for more than a certain period of time and the power change does not conform to the normal rules, an alarm for suspected power theft is triggered.

[0073] In this embodiment, the determination of current sudden change fault and voltage amplitude abnormality is specifically as follows:

[0074] For current mutation detection, assume that the average current value during normal operation is The standard deviation is σ, k is the correction coefficient, and the current mutation threshold is When the current value I is detected to meet And the duration exceeds the set time t th When , it is judged as a current mutation fault;

[0075] For voltage amplitude abnormality detection, the voltage rating is assumed to be U r , the allowable fluctuation range is ±ΔU, when the voltage value U satisfies U<U r (1-ΔU) or U>U r (1+ΔU), it is judged as abnormal voltage amplitude fault; three-phase unbalance When ε>ε th When , it is judged as a three-phase unbalanced fault.

[0076] In this embodiment, the fault location algorithm model is used to determine the line segment where the fault location is located for fault location. Specifically, the fault location algorithm based on the traveling wave principle is used. Assume that the distance from the fault point to the monitoring point 1 is x, the propagation speed of the traveling wave on the transmission line is υ, the time of fault occurrence is t0, the time when the fault traveling wave first arrives at the monitoring point 1 is t1, and the time when the fault traveling wave first arrives at the monitoring point 2 is t2. Then the position of the fault point is L is the line inductance per unit length, and C is the line capacitance per unit length.

[0077] In summary, the present invention has the following technical advantages:

[0078] 1. Improve monitoring accuracy and reliability

[0079] The high-precision wide-area synchronous sampling technology based on the Beidou timing module ensures that the distribution terminals at different locations are precisely synchronized in time with minimal errors. This makes the measurement data of electrical quantities such as the three-phase phase (line) current and the voltage of the two side phases relative to the middle phase highly consistent on the time axis, providing a solid foundation for subsequent data analysis. Whether it is the power quality assessment under normal operating conditions or the analysis of electrical quantity changes when a fault occurs, accurate and synchronous information can be obtained, greatly improving the reliability of the monitoring results. For example, when analyzing three-phase imbalance problems, the synchronously measured data can accurately reflect the real-time relationship between the phases, accurately judge the degree and cause of imbalance, and effectively avoid misjudgment caused by asynchronous measurement.

[0080] 2. Achieve fast and accurate troubleshooting

[0081] The fast fault alarm function can detect abnormalities in time at the moment of fault occurrence. Through the preset fault judgment logic, such as accurate detection of current mutation exceeding the threshold, abnormal voltage amplitude or excessive three-phase imbalance, the fault type can be quickly located. The wide-area synchronous fault location method based on the traveling wave principle uses transient waveform data provided by multiple terminals, combined with precise time synchronization, to accurately calculate the location of the fault point. This greatly shortens the troubleshooting and repair time, reduces the scope of power outages, effectively improves power supply reliability, ensures normal power supply for users, and reduces economic losses and social impacts caused by power outages. For example, in a complex urban power distribution network, once a fault occurs, it can quickly determine which line segment the fault point is located, and the operation and maintenance personnel can quickly go to deal with it to avoid large-scale and long-term power outages.

[0082] 3. Comprehensive advantages brought by multifunctional integration

[0083] Functional integration: It integrates multiple functions such as line monitoring, power extraction, anti-electricity theft, data collection and upload, and peripheral equipment data interaction, which reduces the number and types of equipment required in the power distribution system and simplifies the system architecture and management process. For example, there is no need to install multiple devices with different functions to achieve monitoring, power extraction, and anti-electricity theft functions, which reduces the cost of equipment installation and maintenance and improves overall management efficiency.

[0084] 4. Enhance the ability to adapt to complex power distribution environments

[0085] The double isolation technology of the current transformer, the first-level current measurement coil and the magnetic core are filled with epoxy resin with excellent insulation performance, which can withstand a withstand voltage of 48KV. The second-level small current transformer is also an electronic current transformer filled with epoxy resin, which ensures safe and reliable measurement under a 10KV high-voltage environment, effectively improving the pressure resistance and anti-interference performance of the equipment, and ensuring the accuracy and stability of the measurement data. For example, in a strong electromagnetic interference environment, it can still work stably and accurately measure the current value.

[0086] The dual-line voltage power supply technology uses high-voltage capacitors to divide the voltage on both sides (phase A and phase C) and uses a power supply transformer to supply power. The dual-line power supply is combined after rectification and filtering to supply power to the terminal and charge the battery at the same time. The backup supercapacitor equipped in the power supply circuit provides short-term power support when the external power supply is abnormal. This enables the terminal to obtain power stably under different line conditions (such as voltage fluctuations, power outages, etc.), ensuring the continuous operation of key terminal functions, extending the service life of the equipment, and improving the reliability and availability of the equipment in complex power distribution environments.

[0087] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A wide area synchronous power distribution monitoring system, characterized in that: include: A plurality of synchronous power distribution terminals are arranged in the power distribution network, wherein the plurality of synchronous power distribution terminals are wirelessly connected to a 4G / 5G base station, the 4G / 5G base station is wirelessly connected to a server, and the server is wirelessly connected to a mobile monitoring terminal and a large monitoring screen; The synchronous power distribution terminal comprises an A-phase unit, a B-phase unit and a C-phase unit, wherein the B-phase unit is a main unit and the A-phase unit and the C-phase unit are auxiliary units; The A-phase unit and the C-phase unit respectively include an electronic current transformer, an electronic voltage transformer, a high-voltage power supply capacitor and a power supply transformer, wherein the A-phase unit electronic voltage transformer and the C-phase unit electronic voltage transformer are respectively connected between the AB phase and between the BC phase; The B-phase unit includes an electronic current transformer, a power supply module, a power supply group, a high-speed ADC sampling circuit, a processor circuit, a 4G module, an encryption chip, a Bluetooth circuit, a clock circuit, a Beidou timing circuit, a first storage chip, a second storage chip, and a battery. The processor circuit is electrically connected to the power supply group, the high-speed ADC sampling circuit, the 4G module, the encryption chip, the Bluetooth circuit, the clock circuit, the Beidou timing circuit, the first storage chip, the second storage chip, and the battery. The power supply group is electrically connected to the power supply module. The power taking module is electrically connected to the power taking transformers of the A phase unit and the C phase unit, and the high-speed ADC sampling circuit is electrically connected to the electronic voltage transformers of the A phase unit and the C phase unit and the electronic current transformers of the A phase unit, the B phase unit and the C phase unit.

2. The wide area synchronous power distribution monitoring system according to claim 1, characterized in that: The electronic current transformers of the A-phase unit, the B-phase unit and the C-phase unit all adopt a secondary current mutual inductance structure.

3. The wide area synchronous power distribution monitoring system according to claim 1, characterized in that: The power taking module is electrically connected to the secondary of the A-phase power taking transformer corresponding to the A-phase unit and the C-phase power taking transformer corresponding to the C-phase unit. The primary of the A-phase power taking transformer and the C-phase power taking transformer are respectively connected to the A-phase power line and the C-phase power line through corresponding high-voltage power taking capacitors.

4. The wide area synchronous power distribution monitoring system according to claim 1, characterized in that: The electronic voltage transformer input ends of the A-phase unit and the C-phase unit are connected to the A-phase power line and the C-phase power line respectively through a high-voltage capacitor voltage divider circuit.

5. The wide area synchronous power distribution monitoring system according to claim 3, characterized in that: The power taking module is electrically connected to the supercapacitor, and includes a rectifier and filter submodule, a DC-DC submodule, a control submodule, and a protection submodule. The rectifier and filter submodule, the DC-DC submodule, the protection submodule and the control submodule are electrically connected, and the input end of the rectifier and filter submodule is electrically connected to the secondary of the power taking transformer.

6. The wide area synchronous power distribution monitoring system according to claim 2, characterized in that: Insulating epoxy resin is poured between the coil and the magnetic core of the secondary current mutual inductance structure of the electronic current mutual inductance to achieve voltage-resistant isolation.

7. A working method of a wide area synchronous power distribution monitoring system, the working method is based on the system according to any one of claims 1 to 6, characterized in that: The following steps are involved: The high-speed sampling ADC unit circuit of the synchronous power distribution terminal samples the voltage and current data of the distribution network according to the set sampling frequency; the voltage and current data include the A, B, and C phase currents I of the A phase unit, B phase unit, and C phase unit measured and detected by the electronic current transformer. A ,I B ,I C , and the AB phase and BC phase line voltage U of the A phase unit and the C phase unit detected by the electronic voltage transformer relative to the B phase AB , U BC ; The voltage and current data of the distribution network collected by each synchronous distribution terminal are sent to the server via the 4G / 5G network. The server monitors the received data in real time to judge the current mutation fault and the voltage amplitude abnormality. If a fault occurs, the server collects synchronous sampling data from multiple synchronous distribution terminals before and after the fault occurs, analyzes the characteristics including the direction of fault current flow and phase change, and uses the fault location algorithm model to determine the line section where the fault is located for fault location.

8. The working method of the wide area synchronous power distribution monitoring system according to claim 7, characterized in that: The working method also includes using an electricity theft judgment algorithm to determine whether there is electricity theft behavior, and the electricity theft judgment algorithm includes calculating the power comparison factor Δ p , current and voltage phase relationship factor Δ θ , current voltage mutation factor Δ a , for power contrast factor Δ p , current and voltage phase relationship factor Δ θ , current voltage mutation factor Δ a Normalize and factor the normalized Assign weights K1, K2, and K3 respectively and calculate the judgment criteria for electricity theft When Δ S Exceeding the preset threshold It is determined that electricity theft has occurred.

9. The working method of the wide area synchronous power distribution monitoring system according to claim 7, characterized in that: The determination of current mutation fault and voltage amplitude abnormality is specifically as follows: For current mutation detection, assume that the average current value during normal operation is The standard deviation is σ, k is the correction coefficient, and the current mutation threshold is When the current value I is detected to meet And the duration exceeds the set time t th When , it is judged as a current mutation fault; For voltage amplitude abnormality detection, the voltage rating is assumed to be U r , the allowable fluctuation range is ±ΔU, when the voltage value U satisfies U<U r (1-ΔU) or U>U r (1+ΔU), it is judged as abnormal voltage amplitude fault; three-phase unbalance When ε>ε th When , it is judged as a three-phase unbalanced fault.

10. The working method of the wide area synchronous power distribution monitoring system according to claim 7, characterized in that: The fault location algorithm model is used to determine the line segment where the fault location is located for fault location. Specifically, the fault location algorithm based on the traveling wave principle is used. Assume that the distance from the fault point to the monitoring point 1 is x, the propagation speed of the traveling wave on the transmission line is υ, the time of fault occurrence is t0, the time when the fault traveling wave first arrives at the monitoring point 1 is t1, and the time when the fault traveling wave first arrives at the monitoring point 2 is t2. Then the position of the fault point is L is the line inductance per unit length, and C is the line capacitance per unit length.

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