CN113691013A - Little electric wire netting observes and controls protection equipment - Google Patents

Abstract

The invention relates to a micro-grid measurement and control protection device, and belongs to the technical field of intelligent power grid protection. The invention adopts a synchronous measurement acquisition unit to acquire and process signals, wherein the synchronous measurement acquisition unit utilizes a sampling pulse generator to generate sampling pulse signals which are synchronous in a wide area range, detects electric field and current signals in a microgrid based on the sampling pulse signals, processes the acquired electric field and current signals, and carries out alarm processing when the electric field or the current exceeds a set value so as to record and upload faults. The measurement and control protection device can realize synchronous acquisition of electric field and current signals, process the signals according to the synchronous acquisition result and accurately find faults in time.

Description

Little electric wire netting observes and controls protection equipment

Technical Field

The invention relates to a micro-grid measurement and control protection device, and belongs to the technical field of intelligent power grid protection.

Background

The development of the smart power grid brings new challenges to fault diagnosis, protection and control of the power distribution network. The following aspects are embodied.

(1) The problem of protection and control of mass access of distributed power supplies is urgently to be solved. The large access of the distributed power supply enables the power distribution network to become an active network with normal operation power and fault current flowing in two directions, and a new problem is brought to the protection control of the power distribution network. Under the limitation of factors such as protection control performance, the existing guide rules all make strict limitation on the access capacity of the distributed power supply, which is not beneficial to fully playing the role of the distributed power supply.

(2) The improvement of the power supply quality requirement of the user provides new requirements for the power distribution network protection control technology. For high-tech digital equipment, even a second-level short-time power failure can bring serious economic loss and social influence. Annual blackout losses in the united states are reported to exceed $ 1500 billion; according to the current power supply reliability condition in China, the annual power failure loss also reaches hundreds of billions of yuan RMB. The statistical data of the power failure of the China power reliability management center show that more than 90% of power failure is caused by a power distribution network. The imperfect protection performance is an important reason for more power failure of the power distribution network.

(3) The problem of low operating efficiency needs to be solved. At present, in the overall loss of a power system, the loss of a power distribution network is close to half; the equipment utilization rate of the power distribution network is low, and the annual average load rate is less than 40%. Improving the level of distribution automation and control is an important measure to solve this problem.

The traditional power distribution network protection control technology can be divided into a local control mode (such as current protection, voltage reactive power control and the like) which only utilizes information of a device installation place and a centralized control mode based on a main station. The local control mode is easy to realize and has high action speed, but the utilized information is limited and the control performance is imperfect. The centralized control mode utilizes global information, can optimize control performance, but has a plurality of involved links and low response speed. The distributed intelligent measurement and control technology can improve the protection control performance by utilizing the measurement information of a plurality of stations, can avoid the problem of long communication and data processing delay caused by centralized control of the main station, and is the development direction of the power distribution network protection control technology. At home and abroad, researches for realizing power distribution network protection and feeder automation by applying distributed intelligent control based on an IP network exist, but the researches mostly stay on the development of a specific application system, deep researches on communication networking modes, data and information exchange models, real-time data rapid peer-to-peer exchange technologies, control mechanisms and algorithms, station-domain-level data analysis, fault location and the like are lacked, and a technical system of the system cannot be formed.

On the other hand, at present, secondary equipment for protection of a power distribution network, voltage reactive power control, power distribution monitoring and the like are respectively arranged and independently constructed, interoperability among various equipment is poor, plug and play are difficult to achieve, and the problems of repeated investment and large workload of management and maintenance exist. The method for solving the problems is to construct a unified station domain Internet of things measurement and control terminal for the power distribution network, realize various in-situ control and distributed intelligent control applications and realize high sharing of software and hardware resources; meanwhile, based on the technology of the Internet of things and the container, the measurement and control terminal of the Internet of things has high openness and supports plug and play of automation equipment and application software. At present, the research on the measurement and control terminal of the internet of things of a power distribution website domain is relatively lacked at home and abroad.

The large access of the existing distributed power supply and the improvement of the requirements on power supply quality and operation efficiency make the measurement and control and protection control of the power distribution network face new challenges. The traditional protection control technology based on the centralized and local control modes respectively has the problems of low response speed, limited information utilization and incomplete functions.

Disclosure of Invention

The invention aims to provide a micro-grid measurement and control protection device, which solves the problems of low response speed, limited information utilization and incomplete functions of the existing micro-grid measurement and control protection device.

The invention provides a micro-grid measurement and control protection device for solving the technical problems, which comprises:

the synchronous measurement acquisition unit comprises a signal acquisition unit, a sampling pulse generator and a data processing unit, wherein the signal acquisition unit is used for detecting electric field and current signals in the microgrid according to sampling pulse signals, and the sampling pulse generator is used for generating sampling pulse signals synchronous in a wide area range by taking clock synchronous second pulse signals as synchronous references; and the data processing unit is used for processing the collected electric field and current signals, performing alarm processing when the electric field or the current exceeds a set value, and recording and uploading faults.

The invention adopts a synchronous measurement acquisition unit to acquire and process signals, wherein the synchronous measurement acquisition unit utilizes a sampling pulse generator to generate sampling pulse signals which are synchronous in a wide area range, detects electric field and current signals in a microgrid based on the sampling pulse signals, processes the acquired electric field and current signals, and carries out alarm processing when the electric field or the current exceeds a set value so as to record and upload faults. The measurement and control protection device can realize synchronous acquisition of electric field and current signals, process the signals according to the synchronous acquisition result and accurately find faults in time.

Furthermore, the signal acquisition unit comprises a signal detection circuit, a signal conditioning circuit and an analog-to-digital conversion circuit, wherein the signal detection circuit is used for acquiring electric field and current signals to be detected, the signal conditioning circuit is used for converting the detected signals into electric signals suitable for sampling and analog-to-digital conversion, and comprises a filter circuit, an amplitude adjusting circuit and an amplitude limiting protection circuit, the filter circuit is used for filtering the signals before signal sampling so as to eliminate high-frequency components in the signals and meet the sampling theorem so as to avoid aliasing; the amplitude adjusting circuit is used for carrying out amplitude modulation processing on the acquired signals so as to meet the input requirements of the sampling and AD conversion device; the amplitude limiting circuit is used for limiting the amplitude of the input signal within an allowable range when the input signal is too large.

Furthermore, the signal detection circuit comprises a current signal acquisition module and an electric field signal acquisition module, the current signal acquisition module adopts a current transformer to detect current signals, and the electric field signal acquisition module adopts a capacitance induction circuit to realize the acquisition of electric field signals to ground phase voltage.

Furthermore, the sampling pulse generator comprises a digital phase discriminator, a digital loop filter, a digital voltage-controlled oscillator and a signal adjusting module, wherein the digital phase discriminator detects the phase relation between an input clock signal and a local estimation signal and transmits the lead-lag state of the phase to the digital loop filter; the digital loop filter plays a role in inhibiting false operation caused by noise fluctuation and generates control signals ahead and lag for adjusting the phase of an output signal of the voltage-controlled oscillator; the digital voltage-controlled oscillator adjusts the phase of the signal sclk according to the control signals ahead, lag and adjust from the loop filter, so that the phase of the rising edge of the signal sclk is the same as that of the rising edge of the output signal ppsout from the clock synchronization within a certain error range; the signal adjusting module is used for adjusting the duty ratio and the level of the sclk signal to enable the sclk signal to become a control signal which can be used for signal sampling.

Furthermore, the protection device also comprises a CIM model semantic verification service module, wherein the CIM model semantic verification service module is used for completing CIM model verification through a semantic verification component, providing association verification and topology verification for power equipment data so as to find the missing data association or broken electrical connection relation and timely repair the data.

Furthermore, the protection device further comprises a data transmission publish/subscribe module which adopts an IEC 61968 message publish-subscribe and request-answer mechanism and realizes the publish-subscribe and message routing of each service system through a proxy-based publish-subscribe engine in the service component.

Further, the protection device further comprises a cross-physical isolation transmission module, which is used for being arranged in the safety I/II area and the safety III/IV area so as to realize reverse physical isolation between the safety I/II area and the safety III/IV area.

Further, the protection device further includes a load balancing module, which is used to implement that the load can be shared among the plurality of data bus servers, and when a system or a network fails, the load balancing can be automatically performed, and the servers in the same cluster can be located in different operating system platforms and physical locations.

Furthermore, the protection device further comprises a large message processing module, which is used for reading large messages in groups or segments in the interface server when large messages appear or large files need to be transmitted, then putting the large messages into a message queue according to the reading sequence, and the bus reads the large messages in sequence according to the putting sequence and then carries out integration and recovery.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the present invention;

FIG. 2 is a schematic block diagram of a synchronous measurement acquisition unit of the present invention;

FIG. 3 is a flowchart of the process of the present invention;

FIG. 4 is a flow chart of the interrupt handling of the second pulse of the present invention;

FIG. 5 is a diagram of a terminal system according to the present invention;

fig. 6 is a schematic block diagram of a data processing unit of the present invention.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings.

The microgrid measurement and control protection equipment disclosed by the invention adopts a mode of theoretical research and product development, and is shown in figure 1. The synchronous measurement acquisition unit adopts an external low-power-consumption high-precision A/D conversion circuit to acquire data, an external GPS/Beidou time service module is adopted to perform time synchronization, the high-speed parallel maximum time synchronization precision of the FPGA is utilized, the FPGA with embedded soft cores is adopted to realize filtering, operation, judgment and wave recording, meanwhile, data uploading is realized through an external 2G/3G/4G communication module, the embedded soft core processor of the FPGA has strong real-time performance and parallel processing capacity, the occupied space is small, and the anti-electromagnetic compatibility capacity is strong. The external low-power-consumption high-precision A/D conversion circuit of the synchronous measurement acquisition unit is used for acquiring data, an external GPS/Beidou time service module is used for time synchronization, the high-speed parallel maximum time synchronization precision of the FPGA is utilized, the FPGA with embedded soft cores is used for realizing filtering, operation, judgment and wave recording, meanwhile, data uploading is realized through an external 2G/3G/4G communication module, the embedded soft core processor of the FPGA has strong real-time performance and parallel processing capacity, the occupied space is small, and the anti-electromagnetic compatibility capacity is strong.

In the embodiment of the present invention, as shown in fig. 2, the synchronous measurement and acquisition unit includes a signal acquisition unit, a sampling pulse generator and a data processing unit, the signal acquisition unit is configured to detect electric field and current signals in the microgrid according to sampling pulse signals, and the sampling pulse generator is configured to generate sampling pulse signals synchronized in a wide area range with clock-synchronized pulse signals as a synchronization reference; the data processing unit is used for processing the collected electric field and current signals, performing alarm processing when the electric field or the current exceeds a set value, and recording and uploading faults. The specific working process is shown in fig. 3 and 4.

The signal acquisition unit comprises a signal detection circuit, a signal conditioning circuit and an analog-digital conversion circuit, wherein the signal detection circuit is used for acquiring electric field and current signals to be detected, the signal conditioning circuit is used for converting the detected signals into electric signals suitable for sampling and analog-digital conversion, and comprises a filter circuit, an amplitude adjusting circuit and an amplitude limiting protection circuit, the filter circuit is used for filtering the signals before signal sampling so as to eliminate high-frequency components in the signals, meet the sampling theorem and avoid the generation of aliasing; the amplitude adjusting circuit is used for carrying out amplitude modulation processing on the acquired signals so as to meet the input requirements of the sampling and AD conversion device; the amplitude limiting circuit is used for limiting the amplitude of the input signal within an allowable range when the input signal is too large; the signal detection circuit comprises a current signal acquisition module and an electric field signal acquisition module, the current signal acquisition module adopts a current transformer to detect current signals, and the electric field signal acquisition module adopts a capacitance induction circuit to realize the acquisition of electric field signals to ground phase voltages.

In order to obtain a high-precision current value, a Rogowski coil is selected as a current transformer circuit measuring element of the signal acquisition unit, the Rogowski coil works on the principle that current passing through the center of the coil is converted into a voltage signal proportional to current differential through electromagnetic induction, and the Rogowski coil has the advantages of high measuring precision, wide measuring range, wide frequency range, low cost and the like. The voltage signal generated by the Rogowski coil needs to be reduced into a signal proportional to the measured current through the integrating circuit, in order to prevent noise from being amplified, the voltage signal is subjected to noise filtering before entering the integrating circuit, so that the drift of the voltage signal subjected to integration can be avoided, and because the voltage signal output by the Rogowski coil is very small, an amplifier needs to be added behind the integrating circuit to amplify the signal and then enter the A/D converter.

The electric field signal is collected through the ground phase voltage of the capacitance induction line, when a fault occurs, the line voltage is suddenly changed, the electric field value of the fault phase is reduced, the electric field value of the normal phase is increased, the electric field measurement cannot accurately reflect the actual voltage, and the electric field sudden change quantity is used for starting the logic element in practice. The nyquist sampling theorem requires a sampling rate of 2 times or more the maximum frequency component in the signal, otherwise aliasing may be caused. The sampling rate of the signal acquisition unit determines the highest frequency component that is allowed to be contained in the signal. Therefore, the signal collected by the sensor needs to pass through a low-pass filter to filter out high-frequency signals, and the cut-off frequency of the low-pass filter is 200 Hz.

Because the amplitude of the signal collected by the mutual inductor does not meet the input range of the AD converter, the collected signal needs to be conditioned and then input into a subsequent AD conversion circuit. Signals acquired by the mutual inductor in the design need to be conditioned in two aspects: amplification of signal amplitude and addition of center bias voltage. The signal amplitude amplification is mainly because the amplitude of the signal acquired by the mutual inductor is too small, so that the conversion precision is reduced. The center bias voltage is added mainly because the chip does not allow the input of a negative voltage, which would otherwise cause the damage of the AD conversion chip.

In the signal acquisition unit, once the AD conversion chip is destroyed, the detection and monitoring of the signal can not be completed, and the overlarge amplitude of the input signal is an important reason for the burning of the AD conversion chip. Therefore, it is usually necessary to add a limiting circuit in the design to limit the amplitude of the input signal within the allowed input range of the AD conversion chip, so as to protect the AD conversion chip.

In order to obtain accurate transient zero sequence data, the acquisition unit must realize the function of whole-system synchronous sampling, the synchronous sampling precision needs to reach within at least 100 mus, the GPS synchronous time synchronization principle is utilized, the whole-system acquisition unit synchronously receives second synchronous signals every 1S, the acquisition unit generates interrupt response synchronous signals, the conversion sampling period is started for calibration, and the sampling calibration of the whole-system acquisition unit is realized.

The sampling pulse generator is required to generate sampling pulse signals synchronized in a wide range so as to ensure the synchronism of signal sampling at each position. The method requires that sampling pulse signals in a wide area range have the same phase, and in the concrete implementation, the design of a synchronous second pulse signal from a clock synchronization system is completed by utilizing an all-digital phase-locked loop. Compared with the traditional PLL realized by an analog circuit, the digital phase-locked loop has the advantages of high precision, no influence of temperature and voltage, adjustable loop bandwidth and central frequency programming, easiness in constructing a high-order phase-locked loop and the like. It is essentially a feedback control system. The basic principle is as follows: and comparing the phase of the received code element with the phase of the locally generated synchronous signal by adopting a phase discriminator at a receiving end, and if the phases of the received code element and the locally generated synchronous signal are not consistent, outputting an error signal by the phase discriminator to control the phase of the local synchronous signal until the phase of the local synchronous signal is consistent with the phase of the received signal.

The sampling pulse generator comprises a digital phase discriminator, a digital loop filter, a digital voltage-controlled oscillator and a signal adjusting module, wherein the digital phase discriminator detects the phase relation between an input clock signal and a local estimation signal and transmits the lead-lag state of the phase to the digital loop filter, and when the phase difference is too large and needs to be quickly adjusted, the digital phase discriminator controls the voltage-controlled oscillator to carry out coarse adjustment through an adjust signal; the digital loop filter plays a role in inhibiting false operation caused by noise fluctuation and generates control signals ahead and lag for adjusting the phase of an output signal of the voltage-controlled oscillator; the digital voltage-controlled oscillator adjusts the phase of the signal sclk according to the control signals ahead, lag and adjust from the loop filter, so that the phase of the rising edge of the signal sclk is the same as that of the rising edge of the output signal ppsout from the clock synchronization within a certain error range; the signal adjusting module is used for adjusting the duty ratio and the level of the sclk signal to enable the sclk signal to become a control signal which can be used for signal sampling.

In addition, the protection device also comprises a CIM (common information model) semantic verification service module, a load balancing module, a protocol conversion module, a large message processing module, an information interaction log module, a data transmission publishing/subscribing module and a cross-physical isolation transmission module.

The CIM semantic verification service module is used for completing CIM verification through the semantic verification component, providing association verification and topology verification for the power equipment data so as to find the missing data association or broken electrical connection relation and repair the data in time; the data transmission publish/subscribe module adopts an IEC 61968 message publish-subscribe and request-response mechanism and realizes the publish-subscribe and message routing of each service system through a proxy-based publish-subscribe engine in a service component; and the cross-physical isolation transmission module is used for being arranged in the safety I/II area and the safety III/IV area so as to realize reverse physical isolation between the safety I/II area and the safety III/IV area. The information interaction log module realizes management, maintenance and error correction of the system through the information interaction log, avoids repeated generation and transmission of the same data, improves the operation efficiency of the bus, and is used for providing a high-speed data transmission mechanism through real-time and quasi-real-time data transmission so as to meet the requirement of data interaction.

The protocol conversion module realizes the conversion of communication protocols among the systems, supports multiple data transmission protocols of Http, Ftp, WebService, MQ or JMS, and the bus security mechanism has adapter identity authentication, authority distribution, message encryption transmission, and abnormal alarm security and active defense mechanism; the load balancing module is used for realizing the cluster function among a plurality of data bus servers, so that the servers can share the load, and when a certain system or network fails, the load balancing can be automatically carried out, and the servers in the same cluster can be positioned on different operating system platforms and physical positions; the large message processing module is used for grouping or segmenting reading the large messages in the interface server when large-capacity messages appear or large files need to be transmitted, then putting the large messages into the message queue according to the reading sequence, and the bus sequentially reads the large messages according to the putting sequence and then carries out integration and recovery.

According to the measurement and control protection equipment for the comprehensive energy microgrid, the measurement units are synchronized in high-precision time, the measurement units can obtain energy automatically, the power consumption is low, the high-frequency wide-area measurement is realized, a novel fault study and judgment algorithm is obtained based on the high-precision synchronous measurement, the fault identification and the positioning are realized based on the wide-area measurement, the edge calculation and the cloud and mist coordination, the design, the development and the equipment trial production of hardware, structures and software of the high-precision synchronous measurement and acquisition units are developed, the single-phase earth fault line selection technology of the power distribution network is broken through, the transient continuous wave recording and the fault accurate study and judgment of the power distribution line are realized, and the earth fault line selection and the fault positioning of the power distribution line are realized.

Through the station domain based on the internet of things technology, the station domain is monitored and controlled and the protection control mode is controlled with the distributed intelligence on the spot, and the unified supporting platform of open for distribution network monitoring and protection control application provides, realizes on this basis that the station domain protects, quick fault isolation and resume power supply, novel protection control techniques such as undercurrent earth fault self-healing, distributed generator grid-connected control.

As shown in fig. 5 and 6, the present invention adopts a design idea of distributed measurement and centralized data processing, and the terminal is composed of two parts of devices: distributed sensing units and a central data processing unit. The sensing unit integrates an advanced sensing technology, is suitable for various application scenes, and realizes advanced sensing and unified Internet of things access; the data processing unit integrates various internet of things communication technologies, completes station domain networking with the sensing unit and performs high-speed communication; through the application of key technologies of the Internet of things such as container deployment, plug and play and edge calculation, station domain panoramic information sharing is realized, rapid fault analysis is carried out according to a network topological structure, sensing, protection and control are intelligently and autonomously carried out on a regional power grid, and rapid and accurate judgment, rapid fault study and judgment and isolation of station domain fault equipment are realized. Through the cooperation with the high-precision synchronous measurement acquisition unit, a one-stop solution for measurement and control, line selection, positioning and station area protection is formed.

An industrial personal computer platform with high real-time performance is selected to realize powerful data processing and internet of things communication; performing edge calculation through a management core, realizing software function APP through a container technology, and flexibly configuring and upgrading an application APP according to requirements; the panoramic station domain data are processed in real time through the real-time core, rapid fault analysis is carried out according to a network topological structure, sensing, protection and control are intelligently and independently carried out on a regional power grid, and rapid and accurate judgment, rapid fault study and judgment and isolation of station domain fault equipment are achieved. Communication interfaces such as an electric Ethernet, an optical fiber Ethernet, a power carrier, 4G, NB-IOT, Rola and the like are adopted or reserved to realize cloud interaction with upper systems such as a monitoring master station and a scheduling master station; unified Internet of things access of various sensing units in the station domain is realized through Internet of things communication technologies such as a wired network and a short-distance wireless technology. The communication interface adopts the modularized design, and can be flexibly configured according to the field requirement. The communication interface for local debugging and monitoring adopts an electric Ethernet interface; the interfaces for communication with the master station can be flexibly configured, and the number of the electric Ethernet is not less than 2; the number of optical Ethernet networks is not less than 2 groups. The data processing unit needs to support time synchronization of the sensing unit for realizing high-speed sampling communication, and the time synchronization precision is 10 us.

The container deployment and plug-and-play technology is adopted, the modular design of data acquisition and coordination control functions is realized, the function applications are mutually independent, an interface is provided, and the secondary development of the user functionality is facilitated.

The man-machine interaction of the platform is flexible and diverse, and the state information of the platform and the interval equipment such as operation, communication, alarm, accident and the like can be quickly known through the indicator lamp on the equipment; the PC is accessed into a local debugging port, so that detailed information such as real-time data, historical data, curves, recording waves, alarm accidents and the like can be checked; the access of the liquid crystal display screen, the standard keyboard and the mouse is supported, the operation is convenient and flexible, and the monitoring information is clear at a glance.

The realization of unified Internet of things access: and the sampling sensing unit carry out high-speed data synchronous acquisition through an electric or optical fiber Ethernet, and the data acquisition adopts an independent plug-in design and can be flexibly expanded. And the sensor units are connected with other types of sensor units in a networking manner by adopting a wired network or a short-distance wireless communication mode such as optical fiber, electric Ethernet, RS232, RS485 and the like. The equipment is accessed into a communication port: at least 2 RJ45, 2 RS-232 and 4 RS-485 channels are provided, and a short-distance wireless communication module can be configured as required. The 433M wireless communication mode is currently adopted by default. The 433MHz wireless transceiver module adopts high frequency radio frequency technology, so it is also called RF433 RF small module. The device consists of a single IC radio frequency front end produced by full digital technology and an AVR singlechip of ATMEL, and a miniature transceiver capable of transmitting data signals at high speed performs packaging, error detection and error correction processing on wirelessly transmitted data. All components adopt industrial standards, the operation is stable and reliable, and the volume is small and the installation is convenient. The method is suitable for the wide fields of safety alarm, wireless automatic meter reading, home and industrial automation, remote control, wireless data transmission and the like.

The device is composed of a plurality of modules by adopting a modular design idea, and the structure is flexible. By adopting the latest soc chip design scheme and internally arranging a multi-core floating point type high-performance CPU, high-capacity, high-precision, rapid and real-time information processing is realized; a high-performance high-capacity industrial FPGA, a high-integration transceiver and a fast Ethernet technology are built in the system to form a high-performance hardware system; the complete software anti-interference measures are taken, and the overall anti-interference capacity of the device meets 11 items of anti-interference degree highest-level tests related to the EMC in the IEC61000 standard. And the central data processing unit adopts point-to-point communication with an electric or optical Ethernet to synchronously upload sampling data at a high speed. The number of interfaces is required to support the central data processing unit redundancy mode.

And all the sensing units are distributed and deployed according to an application scene, so that sampling and uploading of the interval voltage (three phases and zero sequence) and the protection current (three phases and zero sequence) are completed. A high-resolution 16-bit parallel A/D converter is adopted, and 160-point (8kHz) high-speed sampling is carried out per cycle in order to meet the function of low-current line selection. At least 6 DC24V are provided for photoelectric isolation, and the SOE resolution is not more than 2 ms. At least 2 relay output contacts (normally open), contact capacity: AC250V, 5A.

In the embodiment of the invention, a large amount of distributed power supplies and energy storage systems in a microgrid are connected, the operation mode of the microgrid is changed, and after the microgrid fails, because of the bidirectional tide characteristics of the distributed power supplies and the energy storage devices, the traditional protection logic, coordination and fixed value adjustment cannot be directly applied.

Claims (9)

1. The utility model provides a little electric wire netting observes and controls protection device which characterized in that, this protection device includes:

the synchronous measurement acquisition unit comprises a signal acquisition unit, a sampling pulse generator and a data processing unit, wherein the signal acquisition unit is used for detecting electric field and current signals in the microgrid according to sampling pulse signals, and the sampling pulse generator is used for generating sampling pulse signals synchronous in a wide area range by taking clock synchronous second pulse signals as synchronous references; and the data processing unit is used for processing the collected electric field and current signals, performing alarm processing when the electric field or the current exceeds a set value, and recording and uploading faults.

2. The microgrid measurement and control protection device according to claim 1, wherein the signal acquisition unit comprises a signal detection circuit, a signal conditioning circuit and an analog-to-digital conversion circuit, the signal detection circuit is used for acquiring electric field and current signals to be measured, the signal conditioning circuit is used for converting the detected signals into electric signals suitable for sampling and analog-to-digital conversion, the signal conditioning circuit comprises a filter circuit, an amplitude adjusting circuit and an amplitude limiting protection circuit, and the filter circuit is used for carrying out filter processing on the signals before signal sampling so as to eliminate high-frequency components in the signals and meet a sampling theorem so as to avoid aliasing; the amplitude adjusting circuit is used for carrying out amplitude modulation processing on the acquired signals so as to meet the input requirements of the sampling and AD conversion device; the amplitude limiting circuit is used for limiting the amplitude of the input signal within an allowable range when the input signal is too large.

3. The microgrid measurement and control protection device according to claim 2, wherein the signal detection circuit comprises a current signal acquisition module and an electric field signal acquisition module, the current signal acquisition module adopts a current transformer to detect a current signal, and the electric field signal acquisition module adopts a capacitive sensing circuit to realize acquisition of an electric field signal to a ground phase voltage.

4. The microgrid measurement and control protection device of claim 1 or 2, wherein the sampling pulse generator comprises a digital phase discriminator, a digital loop filter, a digital voltage-controlled oscillator and a signal conditioning module, the digital phase discriminator detects the phase relationship between an input clock signal and a local estimation signal and transmits the lead-lag state of the phase to the digital loop filter; the digital loop filter plays a role in inhibiting false operation caused by noise fluctuation and generates control signals ahead and lag for adjusting the phase of an output signal of the voltage-controlled oscillator; the digital voltage-controlled oscillator adjusts the phase of the signal sclk according to the control signals ahead, lag and adjust from the loop filter, so that the phase of the rising edge of the signal sclk is the same as that of the rising edge of the output signal ppsout from the clock synchronization within a certain error range; the signal adjusting module is used for adjusting the duty ratio and the level of the sclk signal to enable the sclk signal to become a control signal which can be used for signal sampling.

5. The microgrid measurement and control protection device according to claim 1 or 2, characterized in that the protection device further comprises a CIM model semantic verification service module, and the module is used for completing CIM model verification through a semantic verification component, providing association verification and topology verification for power equipment data, finding missing data association or broken electrical connection relation, and repairing the data in time.

6. The microgrid measurement and control protection device according to claim 1 or 2, characterized in that the protection device further comprises a data transmission publish/subscribe module which adopts an IEC 61968 message publish-subscribe and request-response mechanism and implements publish-subscribe and message routing of each business system through a proxy-based publish-subscribe engine in a service component.

7. The microgrid measurement and control protection device according to claim 1 or 2, characterized in that the protection device further comprises a cross-physical isolation transmission module, and the cross-physical isolation transmission module is used for being arranged in the secure I/II area and the secure III/IV area so as to realize reverse physical isolation between the secure I/II area and the secure III/IV area.

8. The microgrid measurement and control protection device of claim 5, characterized in that the protection device further comprises a load balancing module, the load balancing module is used for realizing load sharing among a plurality of data bus servers, and when a system or a network fails, load balancing can be automatically performed, and servers in the same cluster can be located in different operating system platforms and physical locations.

9. The microgrid measurement and control protection device according to claim 5, characterized in that the protection device further comprises a large message processing module, and the module is used for reading large messages in groups or segments in the interface server when large messages appear or large files need to be transmitted, then putting the messages into a message queue according to a reading sequence, and sequentially reading the large messages according to the putting sequence by the bus, and then performing integration recovery.

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