CN110187221B

CN110187221B - Power distribution network micro PMU fault recording cooperation method and system based on block chain

Info

Publication number: CN110187221B
Application number: CN201910440738.2A
Authority: CN
Inventors: 贠志皓; 王成斌; 石访; 张恒旭
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2019-05-24
Filing date: 2019-05-24
Publication date: 2020-06-30
Anticipated expiration: 2039-05-24
Also published as: CN110187221A

Abstract

The utility model provides a distribution network miniature PMU fault recording cooperation method and system based on a block chain, all miniature PMUs are used as the nodes of the block chain network, the block chain network is constructed, and the judgment process is started: when any micro PMU triggers fault recording, the micro PMU broadcasts the fault recording to the whole block chain network to inform other micro PMUs of cooperative recording, and when some micro PMUs judge the fault according to the real-time detected fault characteristic quantity by using a built-in fault criterion to start the fault recording, corresponding operation is automatically executed. The method realizes the coordination and autonomy between the decentralized management independent of the main station and each micro PMU.

Description

Power distribution network micro PMU fault recording cooperation method and system based on block chain

Technical Field

The disclosure relates to a block chain-based power distribution network micro PMU fault recording cooperation method and system.

Background

The power distribution network is an important component of the power system and is closely related to users. The power distribution network fault diagnosis technology directly influences the reliability of power supply and the safe operation of a distributed power supply, and is always a research hotspot due to the existence of special faults such as weak fault characteristics, large noise interference and the like. The data basis of fault diagnosis is fault recording signals, and the traditional fault recording of the power distribution network is always a bottleneck factor in fault diagnosis due to the limitations that the distribution points are few, no time mark is available, synchronization is difficult and the like.

The appearance of the miniature PMU device brings new opportunities for power distribution network fault diagnosis. The device integrates the functions of synchronous phasor measurement and fault recording, is installed on each node or line, can upload the synchronous phasor measurement to a power grid master station in real time, can judge a power grid fault according to a fault criterion arranged in the device, and then starts fault recording to be recorded locally, so that transient fault waveform data with a time scale is formed to wait for master station waveform calling. The micro PMU device is widely used in the power distribution network, so that the master station can conveniently and accurately acquire fault recording data under the fault condition while acquiring synchronous measurement phasors.

However, in the implementation of a partial algorithm represented by a high-resistance ground fault diagnosis algorithm of a low-current grounding system, except for the need of obtaining the waveform of the micro PMU which automatically starts fault recording because the built-in criterion is satisfied, other node synchronous fault waveform information is also needed for auxiliary judgment, but the micro PMUs which are far away from the fault position cannot autonomously obtain the fault waveform at the corresponding moment because the measured signal cannot meet the fault waveform starting requirement. In order to solve the problem of how to notify the specific micro PMU to start recording, an existing implementation scheme is a centralized scheme in which the micro PMU device that starts recording notifies a master station, and the master station issues a start instruction.

In the centralized scheme of the main station, after receiving a fault signal uploaded by a miniature PMU which automatically starts wave recording, the main station sends a signal to other miniature PMUs according to a communication protocol to inform the miniature PMUs of starting the fault wave recording and waits for the main station to call a waveform. The existing scheme can generally realize the coordination control of the main station on the fault recording start of the miniature PMU, but the existing scheme has many problems that the main station is used as a key link of signal forwarding. The main station receives synchronous phasor signals uploaded at high speed from each device in real time, works with high real-time performance such as state estimation, coordination control and the like are carried out, on the basis of ensuring the basic works, judgment is carried out according to fault recording starting information uploaded by the micro PMU in real time, and the fault recording starting information is sent to other micro PMU starting signals according to a communication protocol.

Disclosure of Invention

In order to solve the problems, the invention provides a fault recording cooperation method and a fault recording cooperation system for a micro PMU of a power distribution network based on a block chain.

In order to achieve the purpose, the following technical scheme is adopted in the disclosure:

a fault recording cooperation method for a miniature PMU of a power distribution network based on a block chain is characterized in that all miniature PMUs are used as nodes of the block chain network, the block chain network is constructed, and a judgment process is started: when any micro PMU triggers fault recording, the micro PMU broadcasts the fault recording to the whole block chain network to inform other micro PMUs of cooperative recording, and when some micro PMUs judge the fault according to the real-time detected fault characteristic quantity by using a built-in fault criterion to start the fault recording, corresponding operation is automatically executed.

To be more specific, the states of all the micro PMUs are checked every set time to determine whether the determination condition is satisfied.

As a further limitation, it is assumed that the micro PMU for spontaneous start recording is located at node i, and the node performs package coding and encryption processing on the recording start time of the micro PMU for spontaneous start recording and triggering other micro PMU recording commands and the Merkle tree by using a hash function at the data layer to form a command packet.

As a further limitation, the node where the spontaneously started recording miniature PMU is located broadcasts the command packet over the network using P2P technology.

As a further limitation, after receiving the broadcasted encrypted command packet, the micro PMU that does not start recording autonomously performs decryption and restoration, then judges whether the command meets the provisions of the intelligent contract by applying a node consensus mechanism such as a byzantine fault-tolerant mechanism and the like on a consensus layer, after each micro PMU that does not start autonomously recognizes the data validity, the micro PMU starts recording simultaneously in coordination with the micro PMU according to the recording start time and the recording command in the command packet, that is, transient waveform data starting at the start time is transferred from a cache to a storage area.

As a further limitation, the fault recording data of each micro PMU is encapsulated into independent blocks with time stamps, and then the blocks formed by the current recording are linked according to the node numbers, stored in a block chain network in a distributed block chain manner, and waiting for the calling of the master station waveform.

The utility model provides a miniature PMU trouble record ripples cooperative system in distribution network based on block chain, includes the block chain network, the block chain network includes five layer architecture, does in proper order:

the data layer is configured to package wave recording data of the miniature PMU and store the data in a decentralized and distributed manner;

a network layer configured to provide a data transmission channel for each micro PMU between each other by using a P2P point-to-point transmission protocol and a verification mechanism;

the consensus layer is configured to utilize a distributed node consensus algorithm to realize data generation and update, ensure that each micro PMU checks the reasonability of the action of the micro PMU of the action according to the consensus algorithm, and the micro PMU of the action can execute operation after consensus is achieved;

a contract layer configured to encapsulate the intelligent contract such that individuals accessing the blockchain execute the operating instructions of the intelligent contract in an orderly manner according to the contract;

and the application layer is configured to encapsulate various application scenes and cases of the block chain.

As a further limitation, after any micro PMU in the network triggers fault recording, the intelligent contract provides a broadcast to the whole network to notify other micro PMUs of cooperative recording. In the contract execution process, the states of all the miniature PMUs are checked once every delta t time, and whether the contract achievement conditions are met is judged.

As a further limitation, when a power system fails, the micro PMU at the corresponding node starts wave recording because the detected fault characteristic value meets the fault wave recording starting criterion, and the micro PMU devices at other nodes that do not start wave recording autonomously also perform wave recording to wait for the master station to call the waveform when necessary.

As a further limitation, after the micro PMUs that are not started autonomously acquire common identification of data validity, the micro PMUs are started autonomously in cooperation with the start of the recording at the same time according to the recording start time and the recording instruction in the command packet, that is, transient waveform data starting at the start time is transferred from the cache to a storage area of the data layer.

Compared with the prior art, the beneficial effect of this disclosure is:

the data storage capacity in the block chain is large, the storage time is long, and the storage requirement of the fault recording data of the miniature PMU can be met. The data format with the time stamp realizes the tracing query of the data. An encryption mechanism, a verification mechanism and a consensus mechanism in the block chain ensure the safe storage and reliable transmission of data;

the block chain scheme adopts a decentralized distributed cooperative operation mode, and the task amount is distributed to each micro PMU, so that the workload of a power distribution network master station is greatly reduced, and the loss caused by the fault of a central node in the traditional centralized management mode is reduced.

The unique data transmission and common identification technology of the block chain can reduce the probability of time delay of the cooperative start of the fault recording of the miniature PMU and the influence caused by error information. The intelligent contract is used as a working guide of each miniature PMU, and an optimal coordination scheme is provided for the miniature PMU to start fault recording.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a smart contract schematic of the present disclosure;

FIG. 2 is a blockchain technology infrastructure of the present disclosure;

FIG. 3 is a block chaining scheme schematic of the present disclosure;

FIG. 4 is a schematic diagram of a master station approach of the present disclosure;

the specific implementation mode is as follows:

the present disclosure is further described with reference to the following drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only relational terms determined for convenience in describing structural relationships of the parts or elements of the present disclosure, and do not refer to any parts or elements of the present disclosure, and are not to be construed as limiting the present disclosure.

In the present disclosure, terms such as "fixedly connected", "connected", and the like are to be understood in a broad sense, and mean either a fixed connection or an integrally connected or detachable connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present disclosure can be determined on a case-by-case basis by persons skilled in the relevant art or technicians, and are not to be construed as limitations of the present disclosure.

By taking reference to the decentralized application of the block chain in the past in the electric power and energy system, the cooperative start problem of each miniature PMU fault recording when the fault of the electric power system occurs is solved, and the novel distributed miniature PMU fault synchronous recording cooperation scheme is provided in the disclosure. The core idea is that by means of a distributed storage technology, an intelligent contract mechanism and a node consensus method of a block chain technology, after a micro PMU at a certain part of a power distribution network triggers fault recording, transient waveform information at a corresponding moment is recorded by cooperation of the block chain technology and other PMUs without interference of a master station, and decentralized management independent of the master station and coordination and autonomy among the micro PMUs are achieved.

A blockchain is a database in which nodes are commonly identified and maintained, and which is supported by data layer, network layer, common identification layer, excitation layer, contract layer, and application layer technologies.

The block chain technique is defined as follows: the block chain technology is a technology for decentralized and distributed storage of 'block + chain' data with time stamps in a network, updating of the data by using a node consensus algorithm, ensuring the safety of the data by using a cryptographic algorithm and realizing data transmission by a block chain individual by using an intelligent contract formed by an automatic script code.

In the block chain type micro PMU fault recording coordination starting scheme, the recording data of the micro PMU are stored in a distributed mode by adopting a block chain type structure, each micro PMU establishes a coordination starting rule through an intelligent contract, the transmission of commands and data is realized by utilizing a network layer technology, the data is added and updated through a node consensus algorithm, and the security of the data is ensured by an encryption algorithm and a verification mechanism. The method specifically comprises the following steps:

data layer

The block chain encapsulates the wave recording data of the miniature PMU, encryption processing is carried out, and each block data is linked with the previous block through specific information, so that a foundation is provided for distributed storage and mutual calling.

The block chain data storage is similar to the cloud storage, but is different from the central mechanism storage of the cloud storage, the block chain adopts decentralized distributed storage, and the integrity of the system cannot be influenced by the damage of part of nodes.

Network layer

Each PMU in the block chain is a microsystem that both downloads data from other PMUs and transfers data to them. The network layer typically employs a P2P point-to-point transport protocol and authentication mechanism. The P2P technology provides that each network participant can download and transfer data, and therefore only depends on the bandwidth and performance of the network participants, not only the performance of a few devices. The characteristics of decentralization, point-to-point, load balance and the like are beneficial to the high-efficiency transmission of network layer data and are matched with the characteristics of decentralization of a block chain.

Consensus layer

And the block chain realizes the generation and the update of data by using a distributed node consensus algorithm. The consensus algorithm is a mathematical algorithm for realizing the trust establishment and the interest acquisition of each micro PMU in the block chain system. When a micro-PMU is to perform an action, other micro-PMUs in the blockchain check the reasonableness of the action according to a consensus algorithm, and the device can perform the operation only after the consensus is achieved. The consensus algorithm is generally implemented by adopting a workload proving mechanism, a rights and interests proving mechanism or an authorized shares proving mechanism.

Excitation layer

Traditional blockchain techniques establish incentive mechanisms to attract participants of the blockchain to actively provide computing power. The technology is not applied yet because the application object of the present disclosure is the miniature PMU of the distribution network.

Contract layer

The block chain technology can make scripts with powerful functions, and system algorithms and mechanisms are packaged, so that individuals accessing the block chain can execute operation instructions in order according to contracts.

A smart contract is a trusted, shared, automatically executing program code that is deployed on a blockchain. The triggering mechanism of the intelligent contract is shown in fig. 1, and is similar to the input and output response mechanism of the control theory, namely when the triggering condition specified by the contract is met, the intelligent contract automatically drives each micro PMU to execute commands and transmit data.

When a power system fails, the micro PMU at the corresponding node starts wave recording because the detected fault characteristic value meets the fault wave recording starting criterion, however, for effective realization of a fault diagnosis algorithm, the micro PMU equipment of other nodes which do not start wave recording spontaneously also needs to record waves to wait for a master station to call the waveforms when needed. The rule and trigger condition for coordinating and starting fault recording among the miniature PMUs are intelligent contract mechanisms which fully utilize block chains.

Application layer

The application layer encapsulates various application scenes and cases of the block chain, provides good technical support for function expansion, and lays a foundation for subsequent perfection of the disclosure.

The basic framework of blockchain technology is shown in fig. 2.

All the miniature PMUs are used as the nodes of the block chain network to construct the block chain network, an intelligent contract is formed on a contract layer, namely, a fault recording cooperative starting contract is defined by the contract: after any miniature PMU in the network triggers fault recording, the miniature PMU broadcasts the fault recording to the whole network and informs other miniature PMU of cooperative recording. In the contract execution process, the states of all the miniature PMUs are checked once every delta t time, and whether the contract achievement conditions are met is judged.

When some micro PMUs judge the fault according to the fault characteristic quantity detected in real time by using the built-in fault criterion and start fault recording, the intelligent contract conditions are achieved, and corresponding operation is automatically executed.

In order to realize the transmission of the recording start command in the blockchain network, assuming that the miniature PMU for spontaneous start recording is located at the node i, firstly, the node packages and codes the recording start time of the miniature PMU for spontaneous start recording and triggers other miniature PMU recording commands and a Merkle tree by adopting a hash function and encrypts the commands to form a command packet at the data layer. The Merkle tree structure is added into the command packet to facilitate other micro PMUs to verify the integrity of the command packet, and the encryption is carried out to ensure the safety of the command packet.

And then the node i broadcasts the command packet in the network layer in the whole network by adopting the P2P technology. The P2P technology is adopted because the micro PMUs in the blockchain network have equal positions and no special nodes, and each micro PMU can provide all services required by the whole network, and the characteristics are very consistent with the P2P network technology.

After receiving the broadcasted encrypted command packet, other miniature PMUs which do not start recording spontaneously perform decryption and restoration, and then judge whether the command meets the regulation of an intelligent contract or not by applying node consensus mechanisms such as a Byzantine fault-tolerant mechanism and the like on a consensus layer so as to avoid executing error commands generated by hardware errors, network congestion or malicious attacks. After the micro PMUs which are not started spontaneously acquire common identification on the data effectiveness, the micro PMUs are started spontaneously and simultaneously record waves in cooperation according to the wave recording starting time and the wave recording instruction in the command packet, namely, transient waveform data starting at the starting time is transferred to a storage area from a cache.

And finally, encapsulating fault recording data of each miniature PMU into independent blocks with time stamps, linking the blocks formed by the current recording according to the node numbers, storing the blocks in a block chain network in a distributed block chain mode, and waiting for calling of the master station waveform.

According to the method and the system, an in-place fault diagnosis application scene can be added in an application layer, and the block chain network directly transmits a fault diagnosis result to the master station, so that the burden of the master station is further reduced.

A block chain fault recording coordination scheme flow chart is shown in fig. 3.

Master station centralized scheme

The distribution network master station is a monitoring center of the state of the distribution network system and is also a regulation and control center of fault treatment. The power distribution network master station can collect data information of the terminal equipment and issue a regulation and control instruction to the terminal equipment through a network. The existing terminal equipment regulation and control mode is mostly established on the basis of a master station centralized management mode.

The main station type micro PMU fault recording cooperative start scheme is a scheme which takes a main station as a core and adopts a centralized management mode to uniformly manage all micro PMUs in a network.

When some miniature PMUs of the power grid trigger fault recording, the main station receives a fault starting signal uploaded by the main station, informs the miniature PMUs which need to be started cooperatively but do not start the recording spontaneously except the miniature PMUs which start the recording spontaneously, and sends a fault recording instruction to the miniature PMUs, so that the miniature PMUs start the recording and record the recording in a local storage system, and waits for a waveform called by the main station to assist the realization of a fault diagnosis algorithm. The main station and each device are contacted by depending on a power private network or a wireless network according to a communication protocol, and the devices do not need to be communicated.

The master station approach mechanism is shown in fig. 4.

The traditional master station system has increasingly improved functions, and meanwhile, the capacity margin of data processing and event analysis reserved at the initial construction stage is gradually reduced. While many micro PMU devices adopt a master station scheme to establish connection with and manage the master station, the large data transmission amount of the micro PMU devices also increases the workload of the master station. This phenomenon becomes more pronounced as the size of the distribution network increases. Moreover, when the workload of the master station processing is large, the processing time of the micro-PMU fault recording coordination starting event may be prolonged, so that the recording of the power grid fault data is delayed, and the fault diagnosis is seriously influenced.

Block chaining scheme

The data storage capacity in the block chain is large, the storage time is long, and the storage requirement of the fault recording data of the miniature PMU can be met. The data format with the time stamp realizes the tracing query of the data. An encryption mechanism, a verification mechanism and a consensus mechanism in the block chain ensure the safe storage and reliable transmission of data.

The block chain scheme adopts a decentralized distributed cooperative operation mode, the task amount is distributed to each micro PMU, the workload of a power distribution network master station is greatly reduced, and the loss caused by the central node fault in the traditional centralized management mode is reduced.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Although the present disclosure has been described with reference to specific embodiments, it should be understood that the scope of the present disclosure is not limited thereto, and those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the present disclosure.

Claims

1. A power distribution network micro PMU fault recording cooperation method based on a block chain is characterized in that: all miniature PMUs are used as nodes of the block chain network, the block chain network is constructed, and the judgment process is started: when any micro PMU triggers fault recording, the micro PMU broadcasts to the whole block chain network to inform other micro PMUs of cooperative recording, and some micro PMUs judge faults by using built-in fault criteria according to real-time detected fault characteristic quantity to start fault recording and automatically execute corresponding operation.

2. The block chain-based power distribution network micro PMU fault recording coordination method according to claim 1, characterized by: and checking the states of all the miniature PMUs once every set time, and judging whether the judgment condition is met.

3. The block chain-based power distribution network micro PMU fault recording coordination method according to claim 1, characterized by: assuming that the miniature PMU for spontaneous startup recording is located at the node i, the node performs package coding and encryption processing on the recording start time of the miniature PMU for spontaneous startup recording and triggers other miniature PMU recording commands and a Merkle tree by adopting a Hash function at the data layer to form a command packet.

4. The block chain-based power distribution network micro PMU fault recording coordination method according to claim 3, characterized by: the node where the miniature PMU for spontaneous start recording is located broadcasts the command packet in the whole network by adopting the P2P technology.

5. The block chain-based power distribution network micro PMU fault recording coordination method according to claim 1, characterized by: after receiving the broadcasted encrypted command packet, the micro PMU which does not start recording spontaneously carries out decryption reduction, then judges whether the command meets the provisions of an intelligent contract or not by applying a Byzantine fault-tolerant mechanism at a common identification layer, and after the micro PMUs which do not start spontaneously carry out common identification on data validity, simultaneously records the waves by cooperating with the self-started micro PMU according to the wave recording starting time and the wave recording instruction in the command packet, namely, transient waveform data starting at the starting time is transferred into a storage area from a cache.

6. The block chain-based power distribution network micro PMU fault recording coordination method according to claim 5, characterized by: fault recording data of each miniature PMU are packaged into independent blocks with time stamps, and then all the blocks formed by the current recording are linked according to node numbers, stored in a block chain network in a distributed block chain mode and wait for waveform calling of a main station.

7. The utility model provides a miniature PMU trouble record ripples cooperative system of distribution network based on block chain which characterized by: the block chain network comprises a five-layer structure, and sequentially comprises the following steps:

8. The system according to claim 7, wherein the micro PMU fault recording coordination system for the distribution network based on the blockchain is characterized in that: after any micro PMU in the intelligent contract specified network triggers fault recording, broadcasting the fault recording to the whole network and informing other micro PMUs of cooperative recording; in the contract execution process, the states of all the miniature PMUs are checked once every delta t time, and whether the contract achievement conditions are met is judged.

9. The system according to claim 7, wherein the micro PMU fault recording coordination system for the distribution network based on the blockchain is characterized in that: when the power system has a fault, the micro PMU at the corresponding node starts wave recording because the detected fault characteristic value meets the fault wave recording starting criterion, and the micro PMU equipment which does not start the wave recording spontaneously at other parts of nodes also needs to record the wave to wait for the master station to call the wave when needed.

10. The system according to claim 7, wherein the micro PMU fault recording coordination system for the distribution network based on the blockchain is characterized in that: after the micro PMUs which are not started spontaneously acquire common identification on the data effectiveness, the micro PMUs are started spontaneously and simultaneously record waves in cooperation according to the wave recording starting time and the wave recording instruction in the command packet, namely, transient waveform data starting at the starting time is converted into a storage area of a data layer from a cache.