PMU expansion module and integration method of PMU expansion module and power utilization information acquisition terminal

Abstract

The invention discloses a PMU expansion module and an integration method of the PMU expansion module and an electricity utilization information acquisition terminal. Wherein the PMU expansion module comprises a high-speed data acquisition unit, a high-precision clock synchronization unit, a high-performance data processing unit and a standardized communication interface unit, the high-speed data acquisition unit is used for performing high-speed sampling on voltage and current signals, the high-precision clock synchronization unit is connected with the high-speed data acquisition unit and is used for realizing high-precision clock synchronization, and the standardized communication interface unit is connected with the high-performance data processing unit. The high-performance data processing unit is connected with the high-speed data acquisition unit and the high-precision clock synchronization unit and is used for calculating and processing PMU data, and the standardized communication interface unit is connected with the high-performance data processing unit and is used for realizing plug-and-play connection and data interaction with an electricity consumption information acquisition terminal.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution networks, and more specifically, to a PMU expansion module and an integration method with an electricity consumption information acquisition terminal. Background Art

[0002] With the rapid development of smart grids, as a key link facing users, the reliable, efficient, flexible, and interactive characteristics of distribution networks have attracted much attention. To achieve intelligent control of distribution networks, more refined and dynamic monitoring of distribution networks is required. Traditional monitoring means mainly rely on distribution automation terminals, such as intelligent distribution transformer terminals (TTUs), feeder terminals (FTUs), fault indicators (FIs), etc., which mainly collect conventional data such as voltage, current, power, and electrical energy, lacking the ability to deeply perceive the real-time dynamic characteristics of distribution networks.

[0003] A PMU is an advanced measuring device that can measure the amplitudes and phase angles of phasors (such as voltage phasors and current phasors) in the power grid in real time, and through high-precision GPS time synchronization technology, achieve synchronous alignment of data between different measuring points. PMUs were initially mainly applied to transmission networks for wide area measurement systems (WAMS). With the development of technology and the reduction of costs, it has gradually become possible to introduce PMUs into distribution networks, and it is expected to establish a distribution network-level dynamic monitoring system (DPMS). However, due to the complexity of distribution networks themselves and the non-standard nature of existing distribution automation terminals, there are still many challenges in large-scale deployment of PMUs in distribution networks.

[0004] Currently, electricity consumption information acquisition terminals, such as low-voltage concentrators and special transformer acquisition terminals, are widely used in the construction of distribution automation in China for electricity consumption information acquisition and management of residential and industrial and commercial users. These terminals have certain metering functions and are equipped with standard sensor interfaces and communication interfaces, providing a natural carrier for the integration of PMU functions. However, electricity consumption information acquisition terminals themselves do not support synchronous phasor measurement, and their hardware and software need to be specifically modified. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a PMU expansion module and an integration method with an electricity consumption information acquisition terminal.

[0006] According to one aspect of the present invention, a PMU expansion module based on an electricity consumption information acquisition terminal is provided, including: a high-speed data acquisition unit, a high-precision clock synchronization unit, a high-performance data processing unit, and a standardized communication interface unit. The high-speed data acquisition unit is used for high-speed sampling of voltage and current signals. The high-precision clock synchronization unit is connected to the high-speed data acquisition unit and is used to achieve high-precision clock synchronization. The high-performance data processing unit is connected to the high-speed data acquisition unit and the high-precision clock synchronization unit and is used to calculate and process PMU data. The standardized communication interface unit is connected to the high-performance data processing unit and is used to achieve plug-and-play connection and data interaction with the electricity consumption information acquisition terminal.

[0007] Optionally, the high-speed data acquisition unit uses a multi-channel synchronous ADC to perform high-speed sampling of voltage and current signals, supports a sampling rate of 12.8 kHz or higher, and has a dynamic range better than 96 dB.

[0008] Optionally, the high-precision clock synchronization unit receives GNSS timing signals and uses PPS pulses and IRIG-B time codes to achieve sub-microsecond clock synchronization.

[0009] Optionally, the high-performance data processing unit is based on an FPGA and ARM heterogeneous computing architecture.

[0010] Optionally, the standardized communication interface unit provides a fiber optic Ethernet interface and supports IEC 61850-90-5 and IEEE C37.118.2 standard protocols.

[0011] According to another aspect of the present invention, an integration method of a PMU expansion module and an electricity consumption information acquisition terminal is provided, including:

[0012] Connect the high-speed data acquisition unit of the PMU expansion module in parallel with the voltage transformer and current transformer of the electricity consumption information acquisition terminal;

[0013] Connect the standardized communication interface unit of the PMU expansion module to the Ethernet interface of the electricity consumption information acquisition terminal;

[0014] Connect the high-precision clock synchronization unit of the PMU expansion module to the GNSS receiving antenna of the electricity consumption information acquisition terminal to achieve the integrated integration of the PMU expansion module and the electricity consumption information acquisition terminal.

[0015] Optionally, the PMU expansion module obtains the working power supply from the electricity consumption information acquisition terminal to achieve integrated power supply.

[0016] Optionally, the PMU expansion module adopts a package and installation structure compatible with the housing size of the electricity consumption information acquisition terminal to achieve the integration of the mechanical structure.

[0017] According to another aspect of the present invention, there is provided an electricity consumption information acquisition terminal, including: an electricity consumption information acquisition terminal integrated with a PMU expansion module.

[0018] According to another aspect of the present invention, there is provided a distribution network monitoring method, including:

[0019] Deploying an integrated electricity consumption information acquisition terminal at key measurement points of the distribution network, and realizing all-round dynamic monitoring of the operation state of the distribution network by accessing the distribution automation master station, wherein the monitoring content includes power flow monitoring, fault diagnosis, harmonic detection, and voltage quality assessment.

[0020] Optionally, the power flow monitoring calculates the real-time active / reactive power flow, network loss level, and economic operation state of the distribution network through the phasor measurement data of the PMU expansion module.

[0021] Optionally, the fault diagnosis uses the phasor changes measured by the PMU expansion module before and after the fault to determine the fault type and fault section, and guides fault isolation and emergency repair.

[0022] Optionally, the harmonic detection uses the high-order harmonic measurement of the PMU expansion module to evaluate the harmonic pollution level of the distribution network and trace the harmonic-exceeding load.

[0023] Optionally, the voltage quality assessment uses the high-precision voltage phasor data of the PMU expansion module to evaluate the voltage qualification rate, flicker, and voltage dip index of the distribution network.

[0024] According to another aspect of the present invention, there is provided a distribution network monitoring system, including: a plurality of electricity consumption information acquisition terminals integrated with PMU expansion modules distributed at each key node of the distribution network, a distribution automation master station, and a communication network, wherein the electricity consumption information acquisition terminal is connected to the distribution automation master station through the communication network, and the distribution automation master station receives and aggregates the PMU data uploaded by the electricity consumption information acquisition terminal, and performs distribution network monitoring analysis and intelligent control.

[0025] Optionally, the distribution automation master station has functions of data access, data storage, online analysis, visual display, and intelligent decision-making, and supports parallel computing and distributed processing.

[0026] Optionally, the communication methods adopted by the communication network include: fiber optic private network and wireless public network.

[0027] Accordingly, the present invention provides a PMU expansion module based on an electricity consumption information collection terminal. Through innovative hardware design and software design, on the basis of not changing the existing terminal functions, the PMU measurement function is integrated, and the sampling, clock, communication and other resources of the terminal itself are fully utilized to minimize the system upgrade cost and provide an economical and efficient PMU solution for the distribution network. This not only enriches the functions of the electricity consumption information collection terminal, but also lays a solid data foundation for applications such as refined management, real-time control, and online analysis of the distribution network, marking an important progress in the construction of distribution automation and distribution Internet of Things, and having important significance for the safe, stable, and reliable operation of the smart grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0029] Figure 1 is a hardware structure block diagram of the PMU expansion module provided by an exemplary embodiment of the present invention;

[0030] Figure 2 is a flowchart of the integration method of the PMU expansion module and the electricity consumption information collection terminal provided by an exemplary embodiment of the present invention;

[0031] Figure 3 is an integration diagram of the PMU expansion module and the electricity consumption information collection terminal provided by an exemplary embodiment of the present invention;

[0032] Figure 4 is a software architecture diagram of the PMU expansion module provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described herein.

[0034] It should be noted that: unless otherwise specifically stated, the relative arrangements, numerical expressions and values of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0035] Those skilled in the art can understand that the terms "first", "second", etc. in the embodiments of the present invention are only used to distinguish different steps, devices or modules, etc., and do not represent any specific technical meaning, nor do they represent an inevitable logical order between them.

[0036] It should also be understood that in the embodiments of the present invention, "a plurality of" may refer to two or more, and "at least one" may refer to one, two or more.

[0037] It should also be understood that for any component, data, or structure mentioned in the embodiments of the present invention, in the absence of clear limitations or contrary implications in the context, it is generally understood to be one or more.

[0038] In addition, the term "and / or" in the present invention is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the associated objects before and after.

[0039] It should also be understood that the present invention emphasizes the differences between various embodiments. Their similarities or similarities can be referred to each other. For the sake of brevity, they will not be elaborated one by one.

[0040] At the same time, it should be understood that for the sake of description, the sizes of the various parts shown in the drawings are not drawn in actual proportional relationships.

[0041] The following description of at least one exemplary embodiment is actually merely illustrative and in no way constitutes any limitation on the present invention and its application or use.

[0042] Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and devices should be regarded as part of the specification.

[0043] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0044] Figure 1 It is a schematic structural diagram of a PMU expansion module provided by an embodiment of the present application. Refer to Figure 1 As shown, the PMU expansion module based on the power consumption information acquisition terminal includes: a high-speed data acquisition unit, a high-precision clock synchronization unit, a high-performance data processing unit, and a standardized communication interface unit. The high-speed data acquisition unit is used to perform high-speed sampling on voltage and current signals. The high-precision clock synchronization unit is connected to the high-speed data acquisition unit and is used to achieve high-precision clock synchronization. The high-performance data processing unit is connected to the high-speed data acquisition unit and the high-precision clock synchronization unit and is used to perform calculations and processing on PMU data. The standardized communication interface unit is connected to the high-performance data processing unit and is used to achieve plug-and-play connection and data interaction with the power consumption information acquisition terminal.

[0045] Optionally, the high-speed data acquisition unit uses a multi-channel synchronous ADC to perform high-speed sampling on voltage and current signals, supports a sampling rate of 12.8 kHz and above, and has a dynamic range better than 96 dB.

[0046] Optionally, the high-precision clock synchronization unit receives GNSS timing signals and uses PPS pulses and IRIG-B time codes to achieve sub-microsecond synchronization, meeting the requirements of the IEEE C37.118.1a-2014 standard.

[0047] Optionally, the high-performance data processing unit is based on an FPGA and ARM heterogeneous computing architecture. It uses the parallel processing ability of the FPGA to implement functions such as phasor calculation, harmonic analysis, and data packaging, and uses the flexible control ability of the ARM to perform tasks such as parameter configuration, status monitoring, and communication management.

[0048] Optionally, the standardized communication interface unit provides a fiber optic Ethernet interface, supports standard protocols such as IEC 61850-90-5 and IEEE C37.118.2, and realizes plug-and-play interconnection with the power consumption information acquisition terminal and interoperability with the dispatching master station.

[0049] The present invention proposes a PMU expansion module based on a power consumption information acquisition terminal. Through innovative hardware design and software design, without changing the existing terminal functions, it integrates PMU measurement functions, fully utilizes the sampling, clock, and communication resources of the terminal itself, minimizes the system upgrade cost, and provides an economical and efficient PMU solution for the distribution network. This not only enriches the functions of the power consumption information acquisition terminal, but also lays a solid data foundation for applications such as refined management, real-time control, and online analysis of the distribution network, marking an important progress in the construction of distribution automation and distribution Internet of Things, and having important significance for the safe, stable, and reliable operation of the smart grid.

[0050] In another embodiment of the present invention, referring to Figure 2 and Figure 3 as shown, a method 200 for integrating a PMU expansion module and a power consumption information acquisition terminal is provided, including:

[0051] Step 201: Connect the high-speed data acquisition unit of the PMU expansion module in parallel with the voltage transformer and current transformer of the power consumption information acquisition terminal;

[0052] Step 202: Connect the standardized communication interface unit of the PMU expansion module to the Ethernet interface of the power consumption information acquisition terminal;

[0053] Step 203: Connect the high-precision clock synchronization unit of the PMU expansion module to the GNSS receiving antenna of the power consumption information acquisition terminal to achieve the integrated integration of the PMU expansion module and the power consumption information acquisition terminal.

[0054] Optionally, the PMU extension module obtains the working power supply from the electricity consumption information acquisition terminal to achieve integrated power supply.

[0055] Optionally, the PMU extension module adopts a packaging and installation structure compatible with the housing size of the electricity consumption information acquisition terminal to achieve the integration of the mechanical structure.

[0056] In another embodiment of the present invention, there is provided an electricity consumption information acquisition terminal, including: an electricity consumption information acquisition terminal integrated with a PMU extension module.

[0057] In another embodiment of the present invention, there is provided a distribution network monitoring method, including:

[0058] Deploy integrated electricity consumption information acquisition terminals at key measurement points of the distribution network, and through access to the distribution automation master station, achieve all-round dynamic monitoring of the operation status of the distribution network, where the monitoring content includes power flow monitoring, fault diagnosis, harmonic detection, and voltage quality assessment.

[0059] Optionally, the power flow monitoring calculates the real-time active / reactive power flow, network loss level, and economic operation status of the distribution network through the phasor measurement data of the PMU extension module.

[0060] Optionally, the fault diagnosis uses the phasor changes measured by the PMU extension module before and after the fault to judge the fault type and fault section, and guide fault isolation and emergency repair.

[0061] Optionally, the harmonic detection uses the high-order harmonic measurement of the PMU extension module to evaluate the harmonic pollution level of the distribution network and trace the harmonic-exceeding load.

[0062] Optionally, the voltage quality assessment uses the high-precision voltage phasor data of the PMU extension module to evaluate the voltage qualification rate, flicker, and voltage dip indicators of the distribution network.

[0063] In another embodiment of the present invention, there is provided a distribution network monitoring system, including: a number of electricity consumption information acquisition terminals integrated with PMU extension modules distributed at key nodes of the distribution network, a distribution automation master station, and a communication network, where the electricity consumption information acquisition terminal is connected to the distribution automation master station through the communication network, and the distribution automation master station receives and aggregates the PMU data uploaded by the electricity consumption information acquisition terminal, and performs distribution network monitoring analysis and intelligent control.

[0064] Optionally, the distribution automation master station has functions such as data access, data storage, online analysis, visualization display, and intelligent decision-making, and supports parallel computing and distributed processing.

[0065] Optionally, the communication network adopts multiple communication methods, such as fiber optic private network, wireless public network, etc., with bandwidth adaptability and link redundancy protection functions to ensure communication quality and real-time performance.

[0066] In this embodiment, taking the electricity consumption information acquisition terminal of State Grid 2022 version (referred to as the new terminal) as an example, the integrated application solution of the PMU expansion module is described in detail.

[0067] 1. Overview of the new terminal

[0068] The electricity consumption information acquisition terminal of State Grid 2022 version is a standardized product formed by integrating new technologies such as edge computing, mobile Internet, and artificial intelligence on the basis of the original type II dedicated transformer terminal, type III low-voltage concentrator, etc. The new terminal adopts a modular design, supports various function combinations such as power metering, power quality monitoring, digital input acquisition, and interactive display, and reserves standard function expansion interfaces. According to different capacities and application scenarios, the new terminal is divided into different specifications.

[0069] 2. Select the access point

[0070] Considering the access convenience and monitoring coverage, in this embodiment, the PMU expansion module is integrated into the new terminal of the dedicated transformer user or the public transformer substation area. It is used in occasions such as the substation area and switchgear, responsible for the acquisition and management of electricity consumption information of important users and key nodes, integrating 6 or more AC sampling channels, and reserving interfaces such as RS485, Ethernet, and SIM card. Select 1 electricity consumption information acquisition terminal in each substation area and directly install the PMU expansion module on its reserved hardware interface.

[0071] 3. Hardware integration design

[0072] The hardware structure of the PMU expansion module is as shown in the appendix Figure 1 It is mainly composed of a high-speed data acquisition unit, a high-precision clock synchronization unit, a high-performance data processing unit, a standardized communication interface unit, etc. To adapt to the interface and power supply conditions of the new terminal, the following optimization design is carried out for the PMU expansion module in this embodiment:

[0073] (1) Voltage and current sampling: The PMU expansion module comes with 7 AC sampling channels, and the range covers different voltage levels such as 10kV and 400V. Considering that the B-specification terminal generally has 6-8 AC sampling channels and built-in qualified potential transformers (PT) and current transformers (CT), the PMU expansion module directly reuses the existing PT / CT of the terminal as the primary side sensing unit, and only connects a high-speed ADC chip in parallel on the secondary side, sharing signal conditioning circuits such as anti-aliasing filters, saving hardware costs. When selecting the ADC chip, the accuracy requirements of the PMU are preferably met, such as using a 24-bit Σ-Δ ADC, supporting a sampling rate of 12.8kHz or higher.

[0074] (2) Clock synchronization: The PMU expansion module uses an OCXO (oven-controlled crystal oscillator) as the local high-stability clock source, and the absolute time accuracy of up to the order of 20 ns can be achieved through B-code calibration. The new terminal is built-in with a Beidou / GPS dual-mode timing module, and the second pulse (PPS) and time code (IRIG-B) interfaces comply with the IEEE 1344 and IEEE C37.118 series standards. The PMU expansion module is connected to the timing module of the terminal through a dedicated PPS / IRIG-B interface line, receives its hardware second pulse and time code, and performs local clock synchronization and timestamp marking.

[0075] (3) Data processing: The data processing unit of the PMU expansion module adopts an FPGA+ARM heterogeneous computing architecture. Among them, the FPGA selects the Xilinx Artix-7 series, and realizes the hardware acceleration of algorithms such as DFT phasor calculation, harmonic analysis, and data packing based on the Verilog hardware description language, and communicates with the ARM through the AXI4 bus. The ARM processor selects the TI AM5728 with a main frequency of 1 GHz and runs a customized Linux operating system, which is responsible for tasks such as PMU parameter management, clock synchronization, and communication protocol processing. The computing resources can be flexibly allocated between the FPGA and the ARM to optimize the edge computing ability.

[0076] (4) Communication connection: The B-specification terminal is equipped with 2 RJ45 Ethernet interfaces and 1 RS485 interface. The PMU expansion module is connected to it in a board-to-board connection method, which ensures high-speed data throughput and is also convenient for the independent upgrade and maintenance of the module. The Ethernet interface transmits the PMU data stream, and the IEC 61850-90-5 is preferentially adopted for the uplink communication protocol to ensure interoperability with the master station, and the transmission rate is not less than 100 Mbps. The RS485 interface is mainly used for local debugging, parameter configuration, etc.

[0077] 4. Software integration design

[0078] The software and hardware platform of the new terminal adopts the unified technical specifications of the State Grid, and is equipped with a "terminal operating system" customized and developed based on the Linux kernel. The software architecture is open and compatible, supporting secondary development. The software architecture of the PMU expansion module is as shown in the appendix Figure 2 and is as unified as possible with the software interface and data specifications of the new terminal to achieve plug-and-play.

[0079] (1) Driver adaptation layer: Responsible for docking with the kernel of the terminal operating system, abstracting the hardware resources of the PMU expansion module, and providing device driver interfaces, mainly including ADC drivers, FPGA drivers, IRIG-B drivers, serial port drivers, etc. It is developed based on the Linux device driver model and supports hot plugging. After power-on, the PMU driver is automatically loaded by the terminal operating system.

[0080] (2) Data acquisition layer: Periodically acquire the original waveform data of voltage and current through ADC drive. After digital filtering and correction compensation are implemented by FPGA, the data is stored in the on-chip RAM of FPGA. The new terminal also has its own sampling task and storage space, and the two operate independently without interference, reducing the coupling degree.

[0081] (3) Data processing layer: Implement DFT phasor calculation through a pipeline in FPGA, solve the amplitude, phase angle, frequency, etc. of fundamental waves and harmonics, and at the same time evaluate the data quality, eliminate invalid data, and perform data compression as needed. ARM is responsible for reading the calculation results from FPGA and encapsulating the data according to the IEEE C37.118 standard. The calculation module supports remote configuration by the master station.

[0082] (4) Clock synchronization layer: The new terminal has metrological clock synchronization capabilities, guaranteed by Beidou / GPS time service. The PMU expansion module is frequency-synchronized and time-synchronized with it. Specifically, the IRIG-B is used to drive and decode the hardware time code, combined with the OCXO clock frequency, and sub-μs-level synchronization is achieved through an improved Kalman filtering algorithm, meeting the PMU time homogeneity and clock stability indicators.

[0083] (5) Communication service layer: The PMU expansion module uses the communication unit and communication link of the new terminal, and adopts a combination of "transparent transmission + parsing" method. It can either directly transmit the original data transparently to the master station, or the terminal communication module can parse the data of the PMU expansion module and upload it in batches after aggregation. The uplink supports multiple methods such as fiber optic private network, 4G / 5G public network, 230MHz wireless private network, etc., and has an encryption and authentication mechanism.

[0084] (6) Application service layer: In response to the management requirements of the PMU expansion module, a dedicated function menu and human-machine interface are added to the "terminal management system" of the new terminal to achieve parameter configuration, version upgrade, status monitoring, working condition diagnosis, etc. of the PMU expansion module. During the debugging stage, it can be accessed through Web or APP methods. The powerful Edge Computing ability of the new terminal can realize intelligent applications of PMU data locally.

[0085] 5. Pilot application plan

[0086] One county-level power supply branch company in a certain city is selected to carry out a pilot application of the new terminal + PMU expansion module, covering 7 distribution transformers and 3 switchgear stations, with a total of 10 monitoring points. The monitoring scope covers all 10kV main lines, some sensitive loads, and distributed power access points.

[0087] (1) Selection of monitoring points: Select 1 B - specification terminal in each of the 7 substations, giving priority to covering substations with complex structures, dense loads, and frequent faults; select 1 B - specification terminal in each of the 3 switching stations, giving priority to covering the ends of branch lines, the outlets of tie lines, and the important power supply sides. Ensure that the monitoring points have a certain representativeness and coverage.

[0088] (2) Integrated installation and commissioning: Technical personnel from the power supply branch company carry portable computers, install PMU expansion modules on the selected terminals, connect to AC sampling signals and clock synchronization signals, and debug through Web mode or on - site wiring to ensure the normal functions of data acquisition, clock synchronization, data upload, etc. of the PMU expansion modules.

[0089] (3) Networking communication configuration: The data of the PMU expansion modules at 10 monitoring points are accessed by the local terminal through the optical fiber private network to the distribution main station of the local dispatching. According to the unified point table and data format specifications, transmit the PMU data stream to the main station. The data frame rate is set to 50 frames / s, and the harmonics are limited within the 13th order. The main station can send control frames as needed to adjust the acquisition frequency, communication mode, start - stop status, etc. of the PMU expansion modules.

[0090] (4) Artificial intelligence application: The distribution main station aggregates the PMU data of each monitoring point. After data governance and feature engineering, construct AI algorithm models such as fault identification, load modeling, harmonic tracing, and low - voltage line loss calculation. The fault identification model establishes phasor mutation templates for typical faults and realizes fault type judgment (such as single - phase grounding, two - phase short - circuit, etc.) and fault range positioning through template matching; the load modeling uses the statistical characteristics of phasor data to depict the fine portraits of different types of loads (such as active / reactive demand, daily load curve, Z - I characteristics, etc.) for load decomposition and prediction; the harmonic tracing model installs low - cost PMU chips on the user side and finds the responsible party for harmonics through the correlation analysis of harmonic amplitude, direction, impedance, etc.; the low - voltage line loss calculation model uses the PMU data on both sides of the distribution transformer, combines the actual network topology and wire parameters, and calculates the current distribution and power flow loss of the low - voltage line. Through the closed - loop business process of human - machine collaboration, convert PMU big data into the productivity of distribution network lean operation and maintenance.

[0091] 6. Application effect evaluation

[0092] After 3 months of stable operation in the pilot county, good application effects have been achieved:

[0093] (1) The fault identification accuracy rate reaches 95%, the positioning error does not exceed 100 meters, and the average processing time is shortened from 10 minutes to within 2 minutes, significantly improving the distribution network power supply reliability index;

[0094] (2) The accuracy of the big data pest control and electricity theft identification model exceeds 90%, and the accuracy of the power consumption anomaly analysis model exceeds 85%, effectively blocking the leakage points of electricity fees and improving operating efficiency;

[0095] (3) The error rate of the low-voltage line loss calculation model was controlled within 5%, the line loss rate of the substation area generally decreased by 3 to 5 percentage points, more than 10 high-loss substation areas were accurately identified, and a distribution network loss reduction and efficiency improvement strategy was formulated;

[0096] (4) The harmonic source tracing model has identified 86 users with seriously excessive harmonic emissions. Through on-site verification, the accuracy rate of diagnosis is over 95%, which helps customers to reduce the harmonic emissions of their equipment through transformation.

[0097] (5) The three-dimensional distribution network map integrating PMU data realizes the panoramic visualization management of the distribution operation status. Artificial intelligence technology enables distribution automation and smart electricity use, which has been fully recognized by front-line employees.

[0098] This embodiment shows that the integrated application of PMU extension modules and new power consumption information collection terminals has greatly improved the efficiency and refinement of distribution network operation and maintenance, explored a new model of ubiquitous intelligent perception driven by big data, and will play an important role in promoting the construction of a world-class urban power grid with "three types and two networks", innovating energy ecology and service systems, and accelerating digital transformation and high-quality development. In the next step, the city will promote the successful experience of this embodiment, accelerate large-scale deployment throughout the city, and help build a modern power distribution and consumption Internet of Things that is safe, reliable, clean, efficient, interactive, friendly, open and compatible.

[0099] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A PMU expansion module based on a power consumption information collection terminal, characterized in that: include: A high-speed data acquisition unit, a high-precision clock synchronization unit, a high-performance data processing unit and a standardized communication interface unit, wherein the high-speed data acquisition unit is used to perform high-speed sampling of voltage and current signals, the high-precision clock synchronization unit is connected to the high-speed data acquisition unit to achieve high-precision clock synchronization, the high-performance data processing unit is connected to the high-speed data acquisition unit and the high-precision clock synchronization unit to achieve calculation and processing of PMU data, and the standardized communication interface unit is connected to the high-performance data processing unit to achieve plug-and-play connection and data interaction with the power consumption information collection terminal.

2. The PMU expansion module according to claim 1, characterized in that: The high-speed data acquisition unit uses a multi-channel synchronous ADC to perform high-speed sampling on voltage and current signals, supporting a sampling rate of 12.8 kHz and above.

3. The PMU expansion module according to claim 1, characterized in that: The high-precision clock synchronization unit receives the GNSS timing signal and uses the PPS pulse and IRIG-B time code to achieve sub-microsecond clock synchronization.

4. The PMU expansion module according to claim 1, characterized in that: The high-performance data processing unit is based on FPGA and ARM heterogeneous computing architecture.

5. The PMU expansion module according to claim 1, characterized in that: The standardized communication interface unit provides a fiber optic Ethernet interface and supports IEC 61850-90-5 and IEEE C37.118.2 standard protocols.

6. A method for integrating the PMU extension module and the power consumption information collection terminal according to any one of claims 1 to 5, characterized in that: include: Connect the high-speed data acquisition unit of the PMU extension module in parallel with the voltage transformer and current transformer of the power consumption information collection terminal; Connecting the standardized communication interface unit of the PMU extension module to the Ethernet interface of the power consumption information collection terminal; The high-precision clock synchronization unit of the PMU extension module is connected to the GNSS receiving antenna of the power consumption information collection terminal to achieve integrated integration of the PMU extension module and the power consumption information collection terminal.

7. The integration method according to claim 6, characterized in that: The PMU extension module obtains working power from the power consumption information collection terminal to achieve integrated power supply.

8. The integration method according to claim 6, characterized in that: The PMU extension module adopts a packaging and installation structure that is compatible with the shell size of the power consumption information collection terminal to achieve the integration of mechanical structure.

9. An electricity consumption information collection terminal integrated by the method described in any one of 6-8, characterized in that: include: Electricity consumption information collection terminal integrated with PMU expansion module.

10. A distribution network monitoring method implemented by the power consumption information collection terminal according to claim 9, characterized in that: include: The power consumption information collection terminal is deployed and integrated at the key measuring points of the distribution network, and is connected to the distribution automation master station to realize all-round dynamic monitoring of the distribution network operation status, wherein the monitoring content includes power flow monitoring, fault diagnosis, harmonic detection and voltage quality assessment.

11. The monitoring method according to claim 10, characterized in that: The power flow monitoring calculates the real-time active / reactive power flow, network loss level and economic operation status of the distribution network through the phasor measurement data of the PMU extension module.

12. The monitoring method according to claim 10, characterized in that: The fault diagnosis utilizes the phase change measured by the PMU extension module before and after the fault to determine the fault type and fault section, and guide the fault isolation and emergency repair.

13. The monitoring method according to claim 10, characterized in that: The harmonic detection utilizes the high-order harmonic measurement of the PMU extension module to evaluate the harmonic pollution level of the distribution network and trace the source of the excessive harmonic load.

14. The monitoring method according to claim 10, characterized in that: The voltage quality assessment utilizes the high-precision voltage phasor data of the PMU extension module to assess the voltage qualification rate, flicker and sag indicators of the distribution network.

15. A distribution network monitoring system, characterized in that: include: A plurality of power consumption information collection terminals with integrated PMU extension modules, a distribution automation master station and a communication network distributed at key nodes of the distribution network, wherein the power consumption information collection terminals are connected to the distribution automation master station via the communication network, and the distribution automation master station receives and aggregates the PMU data uploaded by the power consumption information collection terminals, and performs distribution network monitoring, analysis and intelligent regulation.

16. The distribution network monitoring system according to claim 15, characterized in that: The distribution automation master station has data access, data storage, online analysis, visual display and intelligent decision-making functions, and supports parallel computing and distributed processing.

17. The distribution network monitoring system according to claim 15, characterized in that: The communication methods adopted by the communication network include: optical fiber private network and wireless public network.

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