CN114663091B - Power trading method based on multi-chain blockchain architecture - Google Patents

Abstract

The invention discloses a power transaction method based on a multi-chain block chain architecture, which comprises the following steps: a multi-chain block chain structure is constructed in advance, a plurality of block chains are coupled through a plurality of common nodes, and a transaction objective function and constraint conditions are set; when a transaction demand is generated, each node conducts transaction in a mode of signing an intelligent contract according to a preset transaction target function and a constraint condition, the node competes for the bookkeeping right according to a bookkeeping right consensus algorithm based on an honest value, and the shared node conducts cross-link processing on information between different block chains in the transaction process. According to the invention, by adopting the multi-chain block chain and coupling through the common nodes, various information related to transaction can be selectively shared and verified in the multi-chain architecture, so that the safety is improved; the node user can be guided to obey the intelligent contract by competing the bookkeeping right through the bookkeeping right consensus algorithm based on the integrity value, the priority of the integrity node is improved, the occurrence of malicious behaviors is avoided, and the transaction efficiency and quality are improved.

Description

Power trading method based on multi-chain blockchain architecture

technical field

The invention relates to the field of data security, in particular to a power trading method based on a multi-chain block chain architecture.

Background technique

With the development of distributed energy technology and strong support at the policy level, distributed energy equipment (DER) will be more and more widely used. Traditional electricity consumers are transformed into prosumers with dual attributes of electricity production and consumption. As a relatively independent power grid structure, the microgrid can directly meet the transaction needs of production and consumption users and realize the efficient use of clean energy. It is the main practical scenario for distributed electric energy to participate in power transactions. The traditional microgrid power trading strategy has the phenomenon of lack of trust between the two parties and opaque information, which makes the transaction data in the microgrid system easy to be tampered with, and the transaction efficiency cannot be effectively guaranteed. Therefore, the key point of power system reform at this stage is to establish a safe, efficient and transparent transaction plan.

Blockchain is a distributed database that deeply applies new computer technologies such as cryptographic algorithms, distributed data storage, point-to-point transmission, consensus mechanisms, and smart contracts. The information in the database is shared by all network nodes, and the data manager is fully responsible for data update, and the data update process is also open to all network nodes. Therefore, the blockchain has the characteristics of decentralization, non-tampering, and openness and transparency, which perfectly fits the needs of distributed energy transactions in microgrids. Therefore, blockchain technology provides a research direction and reference basis for solving problems in the field of microgrid power trading.

At present, scholars at home and abroad are researching the introduction of blockchain technology into the field of microgrid power trading from various aspects. In the existing technology, some literatures propose a credit value incentive method based on blockchain technology, which effectively improves the problem of low transaction efficiency between prosumer users. Aiming at the security issues of distributed energy transactions, some literatures have designed a distribution and sales trading platform to make the transaction process of distributed energy between nodes safer and more efficient. Some literature considers the factor of "temporary market" and constructs a random matching market transaction mechanism among multiple subjects to effectively solve the transaction problem among multiple business subjects in the trading market. Some literature proposes a high-performance blockchain management platform that can realize the decentralized autonomy of smart devices, and implement a decentralized autonomous management system. Some literature proposes a power transaction mechanism that can protect the rights and interests of both parties to the transaction, using blockchain technology and multi-signature methods to achieve data security for both parties to the transaction. Some literatures have designed a blockchain-based distribution system distributed energy market architecture to achieve the purpose of deep integration of blockchain advantages and distributed energy transaction characteristics. The above literature plays a positive role in realizing the safety and efficiency of power transactions in microgrids, and also provides references for further optimizing the distributed energy transaction mechanism in the power system. However, there are still two problems in the following aspects: ① The research mainly considers the openness and transparency of the transaction, and does not involve the research on the network security constraints that the distributed energy transaction must abide by, which makes the transaction plan divorced from the actual needs of the safe operation of the power system; ② There is still a problem of node integrity in the process of power trading, and the current research lacks a supervision mechanism to regulate node transaction behavior, which may lead to nodes being driven by interests, resulting in violation of contracts and malicious consensus behaviors.

Contents of the invention

In view of the poor security of the transaction system in the prior art, the present invention provides a power transaction method based on a multi-chain block chain architecture. In order to take into account the dual characteristics of system security constraints and node integrity protection, a multi-chain block chain is constructed. The block chain architecture is used to provide different functions and effectively guarantee the safety and efficiency of transactions between production and consumption user nodes.

The following is the technical scheme of the present invention.

A power trading method based on a multi-chain blockchain architecture, including the following steps:

Pre-build a multi-chain blockchain architecture, multiple blockchains are coupled through several common nodes, and set transaction objective functions and constraints;

When a transaction demand is generated, each node conducts the transaction by signing a smart contract according to the preset transaction objective function and constraints, and competes for the bookkeeping right according to the bookkeeping right consensus algorithm based on the integrity value. Information between blockchains is processed across chains.

The present invention adopts a multi-chain block chain, and different block chains can be configured with different processing modes to achieve different functions. Through the coupling of shared nodes, various types of information related to transactions can be selectively stored in the multi-chain architecture Share and verify to improve security; Compete for bookkeeping rights through the consensus algorithm of bookkeeping rights based on integrity value, which can guide node users to abide by smart contracts, improve the priority of honest nodes, avoid malicious behavior, and improve transaction efficiency and quality.

Preferably, the pre-built multi-chain block chain architecture includes: constructing a transaction chain, a supervision chain, an information chain, and an electric energy chain, wherein the dispatching center node is set as a common node of the transaction chain, the supervision chain, and the electric energy chain, and the transaction The central node is the common node of the transaction chain, information chain and supervision chain, and the rest of the nodes are production and consumption users.

Preferably, the transaction objective function includes:

表示售电用户m在t时刻的出售电量单价；

表示售电用户m在t时刻的出售电量；

表示相对于出售电量的成本函数，表示为：In the formula, S _t represents the overall revenue function of electricity sellers at time t; Ω _A represents the set of electricity sellers;

Indicates the unit price of electricity sold by user m at time t;

Indicates the electricity sold by electricity seller m at time t;

Represents the cost function relative to the electricity sold, expressed as:

的成本系数；In the formula, a, b, and c respectively represent the corresponding power

cost factor;

There is an electricity balance between the electricity seller and the electricity buyer, expressed as:

表示第n个购电方在t时段的需求电量；In the formula, Ω _B represents the set of power buyers;

Indicates the electricity demand of the nth electricity purchaser in the period t;

The range of electricity sales that the electricity seller can choose is:

分别表示第m个售电方在t时段可出售电量的上下限。In the formula

Respectively represent the upper and lower limits of the electricity that the mth electricity seller can sell in the t period.

Preferably, the constraints include:

The balance constraints of point-to-point transactions in the microgrid are:

In the formula: ΔP _i is the adjustment amount of power selling node i; ΔL _j is the adjustment amount of power purchasing node j; {G _P } is the set of electricity sales of all point-to-point transactions; {L _P } is the set of power purchases of all point-to-point transactions ;

Consider thermally and dynamically stable line power flow constraints:

In the formula: P _l,max is the power flow limitation of branch l, whichever is smaller in the middle value of thermal stability and dynamic stability constraints; P _l,0 is the initial power flow of branch l; ΔP _l is the power flow variation of branch l; {L} is the set of all lines;

Consider the dynamic and stable tie line cut set power flow constraints:

为割集C的初始潮流和；

为割集C的潮流变化量；{C_cut}为所有联络线割集集合。In the formula: P _C,max is the power flow limit of the cut set C, which is taken as the dynamic stability constraint;

is the initial power flow sum of the cut set C;

is the power flow variation of cut set C; {C _cut } is the set of cut sets of all contact lines.

Preferably, the integrity value is calculated based on the completion of the smart contract, and the calculation process includes:

表示产消用户j在t时段内为售电用户，

表示产消用户j在t时段内为购电用户，由于产消用户j不能同时处于售电和购电两种状态，所以产消用户的状态约束可以表示为：

set up

Indicates that the production and consumption user j is a power selling user in the period t,

Indicates that prosumer user j is an electricity purchaser during the period t. Since prosumer user j cannot be in the states of selling electricity and purchasing electricity at the same time, the state constraints of prosumer users can be expressed as:

The calculation standard for the integrity value of production and consumption user nodes is:

表示产消用户j的t时段前的诚信值；Q_ij表示产消用户j和产消用户i在智能合约中成交的电量；

表示产消用户j处于售电状态时所产生的实际电量；

表示产消用户j处于购电状态时所消耗的实际电量。In the formula:

Indicates the integrity value of prosumer user j before period t; Q _ij represents the amount of electricity traded between prosumer user j and prosumer user i in the smart contract;

Indicates the actual electricity generated by prosumer user j in the state of selling electricity;

Indicates the actual power consumed by prosumer user j in the power purchasing state.

As a preference, in the multi-chain block chain architecture, credit score calculation and permission classification are performed between nodes through a consensus mechanism based on multi-centered alliance chains, including:

How to change the node's credit points:

为节点交易诚信值进行效益型标准化后的数值，具体计算方法为：In the formula: R _j is the cumulative credit score of the node; α is the weight of consensus integrity; β is the weight of transaction integrity; s _j is the node consensus contribution value, when the node completes the effective consensus in t period, then s _j The value of is 1, otherwise it is 0;

It is the value after benefit-based standardization of the node transaction integrity value. The specific calculation method is:

分别代表在t时段的所有节点中交易诚信值的最大和最小值；In the formula:

Respectively represent the maximum and minimum values of the transaction integrity value in all nodes in the t period;

Nodes are divided into three levels based on the above-mentioned node credit point change method: the first-level nodes are authoritative nodes on the alliance chain; the second-level nodes are verification nodes; the third-level nodes are ordinary nodes; 30% of the institutions are first-level nodes, which take turns to create and broadcast blocks with their own private key signatures; the remaining nodes are second-level nodes, which take turns to check whether the signed blocks are legal; The default is a third-level node, which does not have the right to create blocks and verify blocks; all nodes have the right to share data; the operating results of each node will be added or subtracted according to preset conditions, when the credit score exceeds the preset Automatically adjust the grading when the permission grading boundary is reached.

As a preference, the credit value-based bookkeeping right consensus algorithm includes:

In the formula: H is a hash function; D _j is the root hash value of prosumer user j; K _j represents the random number calculated by prosumer user j; C _j represents the integrity value of prosumer user j; N _differ represents the difficulty of calculation Coefficient; the integrity value of the node is positively correlated with the probability of the node obtaining the bookkeeping right, and the node with the larger the integrity value is easier to obtain the bookkeeping right;

When competing for bookkeeping rights, prosumer user j packs all transaction data in this time slot, and recursively hashes it to obtain the root hash value D _j , prosumer user j performs a large number of exhaustive enumerations, and finds K _j based on the above formula, Pack K _j into the block and broadcast to other prosumer users in the network at the same time. After receiving the corresponding block, other prosumer users will verify the block according to the corresponding C _j in the above formula. If the verification is passed, the corresponding The block is added to the microgrid information chain, and the prosumer user j gets the bookkeeping reward, otherwise the block is deleted.

Preferably, the information chain adopts a decentralized public chain, which is used to register the production and consumption user nodes who want to participate in the retail transaction of microgrid electricity; The central node is responsible for generating new blocks, and other nodes do not have the right to change the information in the new block. Each block on the electric energy chain is used to store the physical information of the system; The transaction information of the storage nodes depends on the information coupling between the transaction center node and the dispatch center node and the other three side chains; the supervision chain adopts a multi-centralized alliance chain to evaluate the integrity value of the transaction behavior of the production and consumption users. Blocks are used to store the integrity value information of transaction nodes.

Preferably, the registration process includes: the information link generates a pair of keys P _a and P _b according to the identity information of the user. When the user is a prosumer user, the user needs to provide the information of the distributed power generation device. Here Basically, the information chain will generate the public key and private key of the distributed power generation device, and the blockchain system will complete the reliable verification of the node identity according to the public key corresponding to the production and consumption user, and the system will generate With digital certificates, active nodes in the network collect and package information in the network to form new blocks, which are written into the blockchain after being verified by other nodes.

Preferably, the cross-chain processing includes:

Cross-chain processing of the transaction chain and the energy chain: the dispatching center node obtains the real-time market transaction records to be verified after the transaction chain's bookkeeping right node generates a new transaction block, and releases it to the energy chain after passing the security verification; Other nodes on the electric energy chain conduct verification. After the verification is passed, the dispatching center node will publish the formed transaction adjustment information ΔM to the transaction chain, and the initial bookkeeping right node will verify the validity of the adjustment plan. After the verification is passed, the initial transaction The plan is updated and released on the whole network;

Cross-chain processing of the transaction chain and the information chain: the transaction center node publishes the block information on the information chain to the transaction chain, providing a reference for the prediction of the transaction power between nodes in the next period;

Cross-chain processing of the transaction chain and the supervision chain: the transaction center node publishes the transaction settlement information after the security check and adjustment to the supervision chain, and the nodes on the supervision chain selectively calculate the integrity value of the transaction node, and then use the consensus mechanism to reach a consensus on the entire network And form a new block and write it into the supervision chain system, the transaction node obtains the block information and publishes it to the transaction chain, and the integrity value information is used as the evaluation index for the next transaction priority selection.

The multi-chain block chain structure of the present invention has the following characteristics:

The design of a multi-centralized transaction chain for point-to-point transactions. Using the maximum profit of production and consumption users inside the microgrid as the objective function, a transaction optimization model is established to realize the reduction of the probability of transactions between production and consumption users and the large power grid while meeting the power demand of production and consumption nodes. The transaction chain adopts a multi-centralized alliance chain, and the node access mechanism depends on the basic information of the node on the information chain and the historical integrity value, which makes the transaction between production and consumption users more secure and efficient. All nodes on the transaction chain reach a consensus through the improved proof of authority (PoA) consensus algorithm.

Centralized power chain design for network security verification. The central node of the electric energy chain is the scheduling node, and the scheduling node is the third party of the transaction, which does not involve economic interests. At the same time, the verification information of the dispatch center will be released to the private chain for verification by other nodes to ensure the reliability of the verification information. Therefore, setting up this node as the central node of the private chain can not only ensure the efficiency of power security verification, but also avoid the opacity and non-disclosure caused by single-node verification.

The design of a multi-center supervision chain that constrains production and consumption user behavior. In the supervision chain system, the transaction center node, as the node coupling the transaction chain and the supervision chain, publishes the final settlement information of the transaction chain to the supervision chain network, and the active nodes in the network can apply to calculate the integrity value of the node in the current transaction cycle. On this basis, according to the improved PoA consensus algorithm, a consensus is reached in the whole network. The integrity value of the node that is finally verified will be written into the blockchain as a priority reference for the next transaction.

Based on the design of decentralized information chain. Each node on the information chain has a complete block information, which stores information such as the address of the prosumer, its own power generation and consumption, and the daily load curve. Due to the large number and variety of nodes on the information chain, the use of public chains can ensure the openness and transparency of user node information. All nodes on the information chain compete with each other through a consensus mechanism based on integrity value to generate bookkeeping right nodes. The integrity value relies on the transaction center node to realize the coupling between the supervision chain and the information chain. At the same time, the user information of all nodes in the information chain can be traced back, and cannot be tampered with, enabling self-determination and self-management of transaction power.

The substantive effects of the present invention include: using the multi-chain block chain to store transaction information in separate chains, establishing a multi-chain block with the transaction chain as the central chain, and the power chain, information chain and supervision chain as auxiliary chains Chain architecture; combined with the multi-chain blockchain architecture taking into account the role of economy, security and supervision attributes, to achieve the purpose of improving transaction performance and security; by improving the consensus mechanism of authoritative proof, the consensus efficiency among the internal nodes of the alliance chain is greatly improved Improve; ensure the reliability and efficiency of transactions between nodes; while performing network security checks on transactions, restrict transactions and consensus behaviors of production and consumption user nodes, in order to solve power transactions based on single-chain blockchain architecture Provide decision support and theoretical support for problems such as low performance of the method.

Description of drawings

Fig. 1 is the flowchart of the embodiment of the present invention;

Fig. 2 is a multi-chain blockchain architecture diagram of an embodiment of the present invention;

Fig. 3 is the coupling operation diagram of the electric energy chain and the transaction chain of the embodiment of the present invention;

Fig. 4 is a flow chart of nodes competing for accounting rights according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of electrical wiring topology of production and consumption user equipment according to an embodiment of the present invention;

Fig. 6 is a transaction result diagram between production and consumption users before the security check in the embodiment of the present invention;

Fig. 7 is a transaction result diagram between production and consumption users after the security check of the embodiment of the present invention;

Fig. 8 is a graph showing changes in credit value of user nodes after 100 transactions of the embodiment of the present invention;

Fig. 9 is a diagram of node transactions between prosumer users based on credit value according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions will be clearly and completely described below in conjunction with the embodiments. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. the embodiment. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be understood that in various embodiments of the present invention, the sequence numbers of the processes do not mean the order of execution, and the execution order of the processes should be determined by their functions and internal logic, rather than by the implementation order of the embodiments of the present invention. The implementation process constitutes no limitation.

It should be understood that in the present invention, "comprising" and "having" and any variations thereof are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to Those steps or elements are not explicitly listed, but may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

It should be understood that in the present invention, "plurality" means two or more. "And/or" is just an association relationship describing associated objects, which means that there can be three kinds of relationships, for example, and/or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone. . The character "/" generally indicates that the contextual objects are an "or" relationship. "Includes A, B and C", "Includes A, B, C" means that A, B, and C are all included, "includes A, B, or C" means includes one of A, B, and C, "Containing A, B and/or C" means containing any 1 or any 2 or 3 of A, B and C.

The technical solution of the present invention will be described in detail below with specific examples. The embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

Example:

The power trading method based on the multi-chain blockchain architecture includes the following steps as shown in Figure 1:

Pre-build a multi-chain blockchain architecture, multiple blockchains are coupled through several common nodes, and set transaction objective functions and constraints;

When a transaction demand is generated, each node conducts the transaction by signing a smart contract according to the preset transaction objective function and constraints, and competes for the bookkeeping right according to the bookkeeping right consensus algorithm based on the integrity value. Information between blockchains is processed across chains.

Among them, the pre-built multi-chain blockchain architecture is shown in Figure 2, including: building a transaction chain, a supervision chain, an information chain, and an electric energy chain. Set the trading center node as the common node of the transaction chain, information chain and supervision chain, and the remaining nodes are production and consumption users.

The information chain adopts a decentralized public chain, which is used to register the production and consumption user nodes who want to participate in the microgrid power retail transaction; the electric energy chain adopts a centralized private chain, and the scheduling center node is responsible for generating new blocks as the central node. Other nodes do not have the right to change the information in the new block. Each block on the energy chain is used to store the physical information of the system; the transaction chain is used as the main chain, using a multi-centralized alliance chain, which only stores the transaction information of the nodes and relies on the transaction center Nodes and dispatch center nodes are coupled with the information of the other three side chains; the supervision chain adopts a multi-centralized alliance chain to evaluate the integrity value of the transaction behavior of production and consumption users, and each block is used to store the integrity value information of the transaction node.

Compared with the existing single-chain blockchain, the multi-chain blockchain structure proposed in this embodiment has the following characteristics: transaction information, user information, physical information and supervision information are deployed separately, and the transaction chain is separately connected to the information chain and electric energy The chain and supervision chain are coupled and run independently. The existing single-chain blockchain not only needs to store transaction information, but also includes power transmission information in order to meet physical constraints, resulting in problems such as a sharp increase in blockchain capacity and performance degradation. In addition, the single-chain blockchain lacks supervision information and cannot effectively restrain the transaction behavior of prosumer users. In the multi-chain blockchain system proposed in this embodiment, the transaction chain as the main chain relies on the transaction center node and the dispatch center to realize information coupling with the other three side chains. The transaction chain adopts a multi-centralized alliance chain, which only stores the transaction information of the nodes, and realizes the efficient storage and implementation of the transaction scheme between the production and consumption user nodes; the electric energy chain adopts a centralized private chain, and the dispatch center is responsible for generating new blocks as the central node. Other nodes do not have the right to change the information in the new block. Each block on the energy chain stores the physical information of the system to realize the fast and safe verification of the transaction plan; the supervision chain adopts a multi-centralized alliance chain, and each block stores the integrity value information of the transaction node to realize the transaction of production and consumption users Effective evaluation of behavior; the information chain adopts a decentralized public chain, and the production and consumption user nodes must register in the chain if they want to participate in the power retail transaction of the microgrid. Prosumer users enter information such as their own power generation and load power into the system, effectively avoiding malicious tampering of information by trading nodes.

The multi-chain block chain structure of the present invention has the following characteristics:

The design of a multi-centralized transaction chain for point-to-point transactions. Using the maximum profit of production and consumption users inside the microgrid as the objective function, a transaction optimization model is established to realize the reduction of the probability of transactions between production and consumption users and the large power grid while meeting the power demand of production and consumption nodes. The transaction chain adopts a multi-centralized alliance chain, and the node access mechanism depends on the basic information of the node on the information chain and the historical integrity value, which makes the transaction between production and consumption users more secure and efficient. All nodes on the transaction chain reach a consensus through the improved proof of authority (PoA) consensus algorithm.

Centralized power chain design for network security verification. The central node of the electric energy chain is the scheduling node, and the scheduling node is the third party of the transaction, which does not involve economic interests. At the same time, the verification information of the dispatch center will be released to the private chain for verification by other nodes to ensure the reliability of the verification information. Therefore, setting up this node as the central node of the private chain can not only ensure the efficiency of power security verification, but also avoid the opacity and non-disclosure caused by single-node verification.

The design of a multi-center supervision chain that constrains production and consumption user behavior. In the supervision chain system, the transaction center node, as the node coupling the transaction chain and the supervision chain, publishes the final settlement information of the transaction chain to the supervision chain network, and the active nodes in the network can apply to calculate the integrity value of the node in the current transaction cycle. On this basis, according to the improved PoA consensus algorithm, a consensus is reached in the whole network. The integrity value of the node that is finally verified will be written into the blockchain as a priority reference for the next transaction.

Based on the design of decentralized information chain. Each node on the information chain has a complete block information, which stores information such as the address of the prosumer, its own power generation and consumption, and the daily load curve. Due to the large number and variety of nodes on the information chain, the use of public chains can ensure the openness and transparency of user node information. All nodes on the information chain compete with each other through a consensus mechanism based on integrity value to generate bookkeeping right nodes. The integrity value relies on the transaction center node to realize the coupling between the supervision chain and the information chain. At the same time, the user information of all nodes in the information chain can be traced back, and cannot be tampered with, enabling self-determination and self-management of transaction power.

The coupling operation mechanism of the transaction chain and the electric energy chain in this embodiment is shown in Figure 3: after the dispatching center node on the transaction chain generates a new transaction block at the accounting authority node, it obtains the real-time market transaction records to be verified and publishes them to the electric energy chain superior. After the dispatch center node checks the security of the initial transaction plan, it is verified by other nodes on the electric energy chain. After the verification is passed, the dispatch center node will publish the formed transaction adjustment information ΔM to the transaction chain. The validity of the adjustment plan is verified by the initial bookkeeping right node. After the verification is passed, the initial transaction plan will be updated and released on the whole network.

The coupling operation mechanism of the transaction chain and the information chain in this embodiment: the transaction chain and the information chain rely on the transaction center to realize the coupling. forecasts for reference.

The coupling operation mechanism of the transaction chain and the supervision chain in this embodiment: the transaction center node on the transaction chain publishes the transaction settlement information after security check and adjustment to the supervision chain. On the supervision chain, active nodes can apply to calculate the integrity value of transaction nodes, and then use the improved PoA consensus mechanism to reach a consensus on the entire network and form a new block to be written into the supervision chain system. The transaction node obtains the block information and publishes it to the transaction chain, and the integrity value information is used as the evaluation index for the priority selection of the next transaction.

In the process of cross-chain, it is necessary to check the block header information submitted by the coupling node, including the digital signature encrypted by public-private key technology and the merkle tree root. The digital signature can guarantee the legitimacy of the data source, and the merkle tree root is used to verify the integrity of the transaction content, effectively ensuring the authenticity of the data source in the cross-chain process.

In the microgrid, each production and consumption user makes quantitative predictions on the amount of tradable electricity in this period based on the power generated by the distributed power source collected by the smart meter and its own power consumption. At the same time, with the goal of maximizing the economic benefits of production and consumption users, optimize the decision-making of their respective power purchases or sales power, and the internal power shortage or surplus power of the microgrid will be purchased from the external network. In a multilateral transaction, the power purchaser and the power seller need to initiate a purchase/sell transaction demand for deviation power to eliminate the deviation between the actual power generation and consumption and the planned value. When in a seller's market environment, the transaction objective function is the highest overall benefit for electricity sellers. When in a buyer's market environment, the transaction goal is to require electricity purchasers to purchase electricity at the lowest price. In this embodiment, the seller's market is taken as an example, and the objective function of the transaction is as follows:

表示售电用户m在t时刻的出售电量单价；

表示售电用户m在t时刻的出售电量；

表示相对于出售电量的成本函数，具体表示为：In the formula, S _t represents the overall revenue function of electricity sellers at time t; Ω _A represents the set of electricity sellers;

Indicates the unit price of electricity sold by user m at time t;

Indicates the electricity sold by electricity seller m at time t;

Represents the cost function relative to the electricity sold, specifically expressed as:

的成本系数。In the formula, a, b, and c respectively represent the corresponding power

cost factor.

There is an electricity balance between the electricity seller and the electricity buyer, which can be expressed as:

表示第n个购电方在t时段的需求电量。In the formula, Ω _B represents the set of power buyers;

Indicates the electricity demand of the nth electricity purchaser in the period t.

The range of electricity sales that the electricity seller can choose is:

分别表示第m个售电方在t时段可出售电量的上下限。In the formula

Respectively represent the upper and lower limits of the electricity that the mth electricity seller can sell in the t period.

The transaction chain selects a multi-centralized alliance chain, and all node blocks store the transaction information of the point-to-point exchange in the power distribution system. As a supervisory node, the transaction center node publishes the transaction information of the prosumer users on the alliance chain to the supervision chain, and the active nodes in the supervision chain apply to calculate the integrity value of the prosumer user nodes, and publish it to all supervision chains. Because the authority proof consensus mechanism (proof of authority, PoA) generates blocks faster and has strong scalability.

The electric energy chain is a self-built private blockchain in the microgrid, which only provides services for production and consumption users of the same voltage level in the region. Based on the multi-centralized transaction chain, all transaction plans reached in the prosumer market must pass the network security check to meet the security constraints of the power system before they are implemented. Therefore, the coupling operation mode of the transaction chain and the electric energy chain is designed, and a network security verification method based on the centralized electric energy chain is proposed to realize a fair verification and reasonable adjustment of the transaction transaction plan D.

The electric energy chain selects a centralized private chain, and all node blocks store the physical data of the point-to-point exchange in the power distribution system, such as transaction power, energy type, etc. As the central node in the private chain network, the dispatch center is responsible for implementing node power security analysis and generating the final block. Other nodes in the power chain only have the function of supervising the accuracy of block information. This can not only improve the efficiency of electric energy security check but also ensure the fairness of electric energy security check.

Electric energy safety check is divided into two aspects: non-free state and free state. This embodiment focuses on the non-free state safety check of the line transmission power balance constraint, while the free state safety check is reflected in the line power flow constraint and tie line cut Set current constraints.

The balance constraints of point-to-point transactions in the microgrid are:

In the formula: ΔP _i is the point-to-point transaction adjustment amount (the adjustment amount of the electricity sales node i); ΔL _j is the point-to-point transaction adjustment amount (the adjustment amount of the electricity purchase node j); {G _P } is the electricity sales set of all point-to-point transactions; {L _P } is the power purchase set of all peer-to-peer transactions.

Consider thermally and dynamically stable line power flow constraints:

In the formula: P _l,max is the power flow limitation of branch l, and the smaller value of the thermal stability and dynamic stability constraints can be taken; P _l,0 is the initial power flow of branch l; ΔP _l is the power flow change of branch l ; {L} is the set of all lines.

Consider the dynamic and stable tie line cut set power flow constraint:

为割集C的初始潮流和；

为割集C的潮流变化量；{C_cut}为所有联络线割集集合。In the formula: P _C,max is the power flow limit of the cut set C, which can be taken as the dynamic stability constraint;

is the initial power flow sum of the cut set C;

is the power flow variation of cut set C; {C _cut } is the set of cut sets of all contact lines.

In the actual market transaction process based on the blockchain, the producers and consumers on the transaction chain reach the Nash equilibrium after a dynamic game, and obtain the final transaction plan, and then use the power chain coupled with it to complete the security calibration of the node transaction power. core to form block adjustment information.

Based on the multi-center supervision chain, the transaction center will publish the transaction information to the supervision chain after the transaction is settled. All nodes on the supervision chain calculate and reach a consensus on the integrity value of the transaction chain nodes. On this basis, the transaction center sorts the integrity value from large to small and publishes the node integrity value to the transaction chain. A node with a higher integrity value will have the priority to recommend in the next cycle of transactions. Therefore, the coupling operation mode of the transaction chain and the supervision chain designed in this embodiment effectively realizes the information exchange between the transaction chain and the supervision chain.

The supervision chain selects a multi-centralized alliance chain, and all node blocks store the settlement information of point-to-point transactions in order to verify and calculate the integrity value of transaction nodes. Both transaction center nodes (third-party profit-making enterprises outside the power distribution system) and prosumers can serve as supervision chain nodes. The nodes of the supervision chain are voted by all production and consumption user nodes, and are comprehensively formulated according to the historical cumulative integrity value. After the confirmation of the supervision chain node group, the active nodes in the system apply for the calculation of the integrity value of the transaction node.

In the process of power trading, there will be problems of breach of contract between the two parties. The actual power generation of the power seller is not equal to the transaction volume, which leads to the need for the power buyer to purchase electricity from the external grid at a price higher than the internal retail price of the microgrid. This not only damages the economic interests of the power buyer but also is not conducive to the development of distributed photovoltaics. The advantages of environmental protection benefits of power generation; and after the power purchaser signs the smart contract, if the power consumption exceeds the agreed value, the interests of the power seller will be damaged. At the same time, as a power purchaser, the act of not saving electricity lacks environmental awareness. Therefore, this embodiment uses the completion of the smart contract as the calculation basis for the integrity value of the production and consumption users, and the calculation method is as follows:

表示产消用户j在t时段内为售电用户，

表示产消用户j在t时段内为购电用户。由于产消用户j不能同时处于售电和购电两种状态，所以产消用户的状态约束可以表示为：suppose

Indicates that the production and consumption user j is a power selling user in the period t,

Indicates that prosumer user j is an electricity purchaser within t period. Since the prosumer user j cannot be in the two states of selling electricity and purchasing electricity at the same time, the state constraints of the prosumer user can be expressed as:

Combined with the state constraints of the above prosumers, the calculation standard for the integrity value of prosumer user nodes can be obtained as follows:

表示产消用户j的t时段前的诚信值；Q_ij表示产消用户j和产消用户i在智能合约中成交的电量；

表示产消用户j处于售电状态时所产生的实际电量；

表示产消用户j处于购电状态时所消耗的实际电量。In the formula:

Indicates the integrity value of prosumer user j before period t; Q _ij represents the amount of electricity traded between prosumer user j and prosumer user i in the smart contract;

Indicates the actual electricity generated by prosumer user j in the state of selling electricity;

Indicates the actual power consumed by prosumer user j in the power purchasing state.

When production and consumption users want to participate in the internal power retail transaction of the microgrid, they need to register their identity information. Due to the large number of production and consumption users, the real-time information is stronger and the information density is higher. Therefore, the information chain adopts a decentralized public chain construction method, making the basic information of production and consumption users open, transparent and more verifiable. All nodes in the information chain can choose whether to participate in the bookkeeping right competition without presetting. Large-scale nodes with server clusters such as trading centers have the highest computing power and storage capacity, and generally operate as full nodes, responsible for outputting computing power and other tasks. Most of the prosumer users are light nodes and only participate in verification and other work. In addition, the transaction center has particularity. It not only needs to participate in the formation of the information chain, but also needs to form a transaction chain with the production and consumption users of the transaction chain and the dispatch center. The information chain not only has the function of collecting and organizing the basic information of power trading users, but also prevents information from being maliciously tampered with, making the data information on the information chain a reliable reference for trading plans.

The information chain generates a pair of keys P _a and P _b according to the identity information of the user. When the user is a prosumer, the user needs to provide the information of the distributed power generation device. On this basis, the information chain will generate the public key and private key of the distributed power generation device, and the blockchain system will complete the reliable verification of the node identity according to the public key corresponding to the prosumer user. The system will generate a digital certificate based on the node's public key and user information, and the active nodes in the network will collect and package the information in the network to form a new block, and the new block will be written into the blockchain after being verified by other nodes.

The introduction of digital certificates is to better manage the users who join the system. When the digital certificates are written into the blockchain system, the users will sign a smart contract with the information chain. The purpose of this smart contract is to protect each user. rights and interests. When some users conduct malicious transactions in the transaction chain, the digital certificate status of the user node will be deducted points. When the user is deducted a certain amount of points, the smart contract will terminate the contract with the relevant user and abolish the user's digital certificate in the information chain according to the content of the contract, resulting in the user being unable to conduct energy transactions.

In the traditional PoA consensus algorithm, it is necessary to specify a group of authorized nodes in advance, and these authorized nodes have the accounting authority of the alliance chain. Therefore, there is no need to rely on computing power to compete for bookkeeping rights, effectively reducing the waste of resources and increasing the block generation speed. However, considering that there may be malicious nodes in the system or transactions between nodes lack integrity and other issues. This embodiment improves the selection method of authorized nodes in the PoA consensus algorithm, and introduces credit points and grading mechanisms, so that the improved PoA consensus algorithm not only retains the original advantages but also effectively supervises the transaction and consensus behavior of nodes.

In this embodiment, credit points are used to represent the credibility of nodes in the microgrid, and the credit points of prosumer user nodes are increased or decreased according to their consensus performance and historical transaction integrity. On this basis, the control of node authority is realized through the hierarchical mechanism, so as to fully mobilize the enthusiasm of each node to actively participate in the management of the alliance chain, and ensure the safe and efficient operation of the system. The way to change the credit score of the node is as follows.

式中：R_j为节点的累计信用积分；α为共识诚信所占的权重；β为交易诚信所占的权重；s_j为节点共识贡献值，当节点在t时段完成有效共识，那么s_j的值为1，否则为0；

为节点交易诚信值进行效益型标准化后的数值，具体计算方法为：

In the formula: R _j is the cumulative credit score of the node; α is the weight of consensus integrity; β is the weight of transaction integrity; s _j is the node consensus contribution value, when the node completes the effective consensus in t period, then s _j The value of is 1, otherwise it is 0;

It is the value after benefit-based standardization of the node transaction integrity value. The specific calculation method is:

分别代表在t时段的所有节点中交易诚信值的最大和最小值。In the formula:

Represent the maximum and minimum values of the transaction integrity value in all nodes in the period t, respectively.

Nodes are divided into three levels based on the above-mentioned node credit point change method: first-level nodes can become authoritative nodes on the alliance chain; second-level nodes are verification nodes; third-level nodes are ordinary nodes.

In the initial stage of system construction, the top 30% of institutions are selected as first-level nodes, which are responsible for creating and broadcasting blocks with their own private key signatures in turn. The remaining nodes are secondary nodes, which check whether the signed blocks are legal in turn. After entering the operation phase, the newly joined nodes are defaulted as third-level nodes, and do not have the right to create blocks and verify blocks. All nodes have the right to share data. After the third-level node joins, it will become a second-level node after completing the data synchronization on the blockchain and running normally for three months. The first-level node will add a certain amount of credit points to create a legal block, and the credit points will be deducted when creating an invalid or false block. The node with the highest score among the level nodes is filled. Similarly, the verification of a valid block by the second-level node will increase the credit points, and the credit points will also be deducted for audit errors or intentional cheating. The points are lower than the threshold and downgraded to the third level. No points will be added for the behavior of sharing data between nodes at all levels.

In the multi-chain blockchain system proposed in this embodiment, the transaction chain and supervision chain are designed in the form of alliance chains. Therefore, using the improved PoA algorithm as the consensus mechanism of the two chains can not only ensure efficient consensus but also constrain the transaction behavior of production and consumption user nodes.

In order to achieve the purpose of influencing the economic benefits of nodes with integrity value, this embodiment proposes a consensus algorithm for bookkeeping rights based on integrity value:

In the formula: H is a hash function; D _j is the root hash value of prosumer user j; K _j represents the random number calculated by prosumer user j; C _j represents the integrity value of prosumer user j; N _differ represents the difficulty of calculation coefficient.

It can be seen from the above formula that the integrity value of a node is positively correlated with the probability of the node obtaining the bookkeeping right, and the node with a higher integrity value is easier to obtain the bookkeeping right. As a result, the consensus algorithm can form a virtuous circle, so that the production and consumption user nodes are willing to abide by the smart contract and maximize their own interests. At the same time, the mutual coupling of the two chains is achieved by using the transaction center node to transmit information between the supervision chain and the information chain . Figure 4 shows the regulation process for production and consumption users to compete for bookkeeping rights.

Considering that the integrity value of a node is a sign to evaluate the completion of the node's smart contract, the transaction method between production and consumption user nodes proposed in this embodiment not only takes into account the security check problem, but also effectively ensures that the node with the highest integrity value has priority trading rights. The specific trading algorithm is shown in Table 1 below.

Table 1 Transaction algorithm based on network security check and integrity value

The actual effect of the method and system of the present embodiment:

In order to verify the feasibility of the power trading method based on the multi-chain blockchain proposed in this embodiment, the smart contract is written in solidity language, and the microgrid trading platform is developed using JavaScript, metamask plug-in, atom, Ethereum platform and web3.js. Assuming that the user numbers participating in a power transaction are 0 to 5, the electrical wiring of these user equipment is shown in Figure 5. The simulated transaction scenario includes 5 production and consumption users and 1 large power grid, and each of these six users corresponds to a transaction chain node. The number of nodes in the electric energy chain is set to 3, among which the dispatching center node serves as the coupling node between the electric energy chain and the transaction chain, and the remaining two nodes are served by prosumer user 1 and prosumer user 2. The number of supervision chain nodes is set to 2, in which the trading center node is the central node of the supervision chain, and the remaining node is the dispatching center node. The number of nodes in the information chain is the same as the number of nodes in the transaction chain, and it is composed of similar users. Prosumers sell electricity to the grid company at a price of 0.5 yuan/(kW·h), and purchase electricity from the grid company at a price of 1.0 yuan/(kW·h). Assume that the weight of consensus integrity is 0.4, and the weight of transaction integrity is 0.6.

In each period, production and consumption users will send status information to the blockchain system according to their own power generation and power consumption. Assume that in a certain period of time, there are three prosumer users who are in a state of power shortage (hereinafter referred to as power purchase users), and the remaining users are in a state of electricity sales during this period (hereinafter collectively referred to as power sellers). Since the addresses of mainstream blockchains such as Ethereum are 42 bits, this embodiment adopts a simplified 8-bit address description, for example, the address of prosumer user 1 is 0xx00x01, and the address of the power grid company is 0xx00x00. The initial quotation information of prosumers before the transaction starts is shown in Table 2.

Table 2 Initial quotation of prosumer user nodes

Prosumer users Prosumer user address Initial quotation/(yuan·(kW·h)^-1) Demand power/kW 1 0xx00x01 0.74 30 2 0xx00x02 0.75 110 3 0xx00x03 0.77 -80 4 0xx00x04 0.79 -40 5 0xx00x05 0.72 60

Figure 6 and Figure 7 show the transaction schemes between prosumer users before and after the verification of the power chain, respectively. It can be seen from the figure that after the safety check of the power chain, the prosumer user 2 cuts a total of 18.5kW of power, which is distributed in proportion, and cuts the transaction power of 3.5kW with prosumer 3 and the transaction power of prosumer 4 6.2kW, and the transaction power with the large power grid is 8.8. However, the power cut between prosumer user 2 and the grid company cannot meet the unit freedom constraints, and the safety check cannot pass, resulting in the failure of point-to-point transactions.

At this time, the dispatching center node gives the point-to-point transaction range of prosumer user 2, that is, the power purchased by this node must not exceed 87.5kW. On this basis, Prosumer 2 reaches a new transaction plan after re-optimizing its decision-making. It can be seen from the comparative deviation of Figure 6 and Figure 7 that the transaction power between the large power grid and the prosumer has decreased by 18.5kW. From this, it can be concluded that the new transaction scheme after security verification satisfies free and non-free constraints, and there is no need to cut the transaction power, and the point-to-point transaction is successfully completed.

If the behavior pattern of the nodes does not change, after all nodes in the system participate in about 100 transactions, the integrity value of the nodes will gradually stabilize. Therefore, this paper simulates 100 randomly generated services based on the evaluation method of node integrity value, and can obtain the change of network node integrity value in Figure 8. It can be clearly seen from the figure that some nodes have higher integrity values, indicating that the nodes have higher transaction integrity and consensus integrity. According to the design of the algorithm mechanism, the transaction priority of prosumer users depends on the integrity value of the node.

Based on this integrity value, the transactions of these nodes are simulated, and the node with the highest integrity value has the priority transaction option. Therefore, the transaction volume of each node is shown in Figure 9, where node 6 represents the large power grid. Combining with the integrity value change graph of the nodes, it can be seen that the integrity value of node 2 is 0.7, which is the lowest among all nodes, and does not have the transaction priority. After the end of the current round of trading cycle, some of the demand of this node will not be met, so it can only trade with the large power grid at a price higher than that of the internal power retail price of the micro-grid to complete the balance of deviation power.

To sum up, the power trading method based on the multi-chain blockchain system proposed in this embodiment can not only realize the network security check of the transaction but also effectively constrain the transaction behavior of nodes, making the transaction process between nodes safer and more efficient.

In a multi-chain blockchain system, transaction data, physical data, node integrity value calculation data, and node identity information data are deployed in separate chains. The transaction chain can handle 12 transactions per second, while the single-chain blockchain can process 12 transactions per second. The number of transactions processed per second is 6. The block confirmation time on the single-chain blockchain includes the confirmation process of node identity registration information, transaction information and check adjustment information, and the total confirmation time is 29.64s. The confirmation of transaction information in the multi-chain blockchain is carried out in the transaction chain, and the confirmation time is 10.32s; the confirmation of the verification and adjustment information is carried out in the electric energy chain. Since the electric energy chain adopts a private chain and the number of nodes is small, the confirmation The shortest time is 3.47s; the confirmation of node identity information is carried out in the information chain. Since only login information and other data are included, the confirmation time is 3.14s; the supervision chain plays the role of supervising the transaction behavior of nodes, although the block Confirm the average time, but also effectively guarantee the reliable implementation of transactions. Therefore, the confirmation of the integrity value calculation information of the nodes is carried out in the supervision chain. Due to the small number of nodes involved, the confirmation time is short, 2.35s. The total confirmation time of the multi-chain blockchain is shorter than that of the single-chain blockchain. It can be seen that in the peer-to-peer transaction scenario, the multi-chain blockchain system has higher transaction processing efficiency and performance.

This embodiment utilizes the feature that the multi-chain blockchain system can store transaction information in separate chains, and establishes a multi-chain blockchain architecture with the transaction chain as the central chain and the power chain, information chain, and supervision chain as auxiliary chains. Combined with the multi-chain blockchain architecture taking into account the role of economy, security and supervision attributes, a transaction optimization model between production and consumption user nodes is constructed to achieve the purpose of improving transaction performance and security. By improving the authority proof consensus mechanism, the consensus efficiency among the internal nodes of the alliance chain is greatly improved. On this basis, a power transaction method based on a multi-chain blockchain architecture is proposed to ensure the reliability and efficiency of transactions between nodes. The analysis of the calculation example shows that the power transaction method based on the multi-chain blockchain architecture proposed in this embodiment can guarantee the security and efficiency of the transaction. Transactions and Consensus Behavior.

Through the description of the above embodiments, those skilled in the art can understand that for the convenience and brevity of the description, only the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned functions can be assigned to different Module completion means that the internal structure of a specific device is divided into different functional modules to complete all or part of the functions described above.

In the embodiments provided in this application, it should be understood that the disclosed structures and methods may be implemented in other ways. For example, the above-described embodiments about the structure are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be Combinations may either be integrated into another structure, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of structures or units may be in electrical, mechanical or other forms.

A unit described as a separate component may or may not be physically separated, and a component shown as a unit may be one physical unit or multiple physical units, which may be located in one place or distributed to multiple different places. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If an integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the software product is stored in a storage medium Among them, several instructions are included to make a device (which may be a single-chip microcomputer, a chip, etc.) or a processor (processor) execute all or part of the steps of the methods in various embodiments of the present application. The above-mentioned storage medium includes: U disk, mobile hard disk, read only memory (read only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk, and other various media that can store program codes.

The above content is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application, and should covered within the scope of protection of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (4)

1. A method for power trading based on a multi-chain block chain architecture, characterized in that it comprises the following steps: Pre-build a multi-chain blockchain architecture, multiple blockchains are coupled through several common nodes, and set transaction objective functions and constraints; When a transaction demand is generated, each node conducts the transaction by signing a smart contract according to the preset transaction objective function and constraints, and competes for the bookkeeping right according to the bookkeeping right consensus algorithm based on the integrity value. Cross-chain processing of information between blockchains; The pre-built multi-chain block chain architecture includes: building a transaction chain, a supervision chain, an information chain, and an electric energy chain, wherein the dispatching center node is set as a common node of the transaction chain, the supervision chain, and the electric energy chain, and the transaction center node is set as a Common nodes of the transaction chain, information chain and supervision chain, and the rest of the nodes are prosumer users; The information chain adopts a decentralized public chain, which is used to register the production and consumption user nodes who want to participate in the microgrid power retail transaction; the power chain adopts a centralized private chain, and the dispatching center node is responsible as the central node To generate a new block, other nodes do not have the right to change the information in the new block. Each block on the energy chain is used to store the physical information of the system; The transaction information depends on the information coupling between the transaction center node and the dispatch center node and the other three side chains; the supervision chain adopts a multi-centralized alliance chain to evaluate the integrity value of the transaction behavior of the production and consumption users, and each block is used for Store the integrity value information of transaction nodes; The transaction objective function includes:

In the formula, S _t represents the overall revenue function of electricity sellers at time t; Ω _A represents the set of electricity sellers;

Indicates the unit price of electricity sold by user m at time t;

Indicates the electricity sold by electricity seller m at time t;

Represents the cost function relative to the electricity sold, expressed as:

In the formula, a, b, and c respectively represent the corresponding power

cost factor; There is an electricity balance between the electricity seller and the electricity buyer, expressed as:

In the formula, Ω _B represents the set of power buyers;

Indicates the electricity demand of the nth electricity purchaser in the period t; The range of electricity sales selected by the electricity seller is:

In the formula

Respectively represent the upper and lower limits of the electricity sold by the mth electricity seller in the t period; The constraints include: The balance constraints of point-to-point transactions in the microgrid are:

In the formula: ΔP _i is the adjustment amount of power selling node i; ΔL _j is the adjustment amount of power purchasing node j; {G _P } is the set of electricity sales of all point-to-point transactions; {L _P } is the set of power purchases of all point-to-point transactions ; Consider thermally and dynamically stable line power flow constraints:

In the formula: P _l,max is the power flow limitation of branch l, whichever is smaller in the middle value of thermal stability and dynamic stability constraints; P _l,0 is the initial power flow of branch l; ΔP _l is the power flow variation of branch l; {L} is the set of all lines; Consider the dynamic and stable tie line cut set power flow constraints:

In the formula: P _C,max is the power flow limit of the cut set C, which is taken as the dynamic stability constraint;

is the initial power flow sum of the cut set C;

is the power flow variation of cut set C; {C _cut } is the set of cut sets of all contact lines; The bookkeeping right consensus algorithm based on integrity value includes:

In the formula: H is a hash function; D _j is the root hash value of prosumer user j; K _j represents the random number calculated by prosumer user j; C _j represents the integrity value of prosumer user j; N _differ represents the difficulty of calculation Coefficient; the integrity value of the node is positively correlated with the probability of the node obtaining the bookkeeping right, and the node with the larger the integrity value is easier to obtain the bookkeeping right; When competing for bookkeeping rights, prosumer user j packs all transaction data in this time slot, and recursively hashes it to obtain the root hash value D _j , prosumer user j performs a large number of exhaustive enumerations, and finds K _j based on the above formula, Pack K _j into the block and broadcast to other prosumer users in the network at the same time. After receiving the corresponding block, other prosumer users will verify the block according to the corresponding C _j in the above formula. If the verification is passed, the corresponding The block is added to the microgrid information chain, and the production and consumption user j gets the bookkeeping reward, otherwise the block is deleted; the cross-chain processing includes: Cross-chain processing of the transaction chain and the energy chain: the dispatching center node obtains the real-time market transaction records to be verified after the transaction chain's bookkeeping right node generates a new transaction block, and releases it to the energy chain after passing the security verification; Other nodes on the electric energy chain conduct verification. After the verification is passed, the dispatching center node will publish the formed transaction adjustment information ΔM to the transaction chain, and the initial bookkeeping right node will verify the validity of the adjustment plan. After the verification is passed, the initial transaction The plan is updated and released on the whole network; Cross-chain processing of the transaction chain and the information chain: the transaction center node publishes the block information on the information chain to the transaction chain, providing a reference for the prediction of the transaction power between nodes in the next period; Cross-chain processing of the transaction chain and the supervision chain: the transaction center node publishes the transaction settlement information after the security check and adjustment to the supervision chain, and the nodes on the supervision chain selectively calculate the integrity value of the transaction node, and then use the consensus mechanism to reach a consensus on the entire network And form a new block and write it into the supervision chain system, the transaction node obtains the block information and publishes it to the transaction chain, and the integrity value information is used as the evaluation index for the next transaction priority selection. 2. The power trading method based on the multi-chain blockchain architecture according to claim 1, wherein the integrity value is calculated based on the completion of the smart contract, and the calculation process includes: set up

Indicates that the production and consumption user j is a power selling user in the period t,

Indicates that prosumer user j is an electricity purchaser during the period t. Since prosumer user j cannot be in the states of selling electricity and purchasing electricity at the same time, the state constraints of prosumer users are expressed as:

The calculation standard for the integrity value of production and consumption user nodes is:

In the formula:

Indicates the integrity value of prosumer user j before period t; Q _ij represents the amount of electricity traded between prosumer user j and prosumer user i in the smart contract;

Indicates the actual electricity generated by prosumer user j in the state of selling electricity;

Indicates the actual power consumed by prosumer user j in the power purchasing state. 3. The power trading method based on the multi-chain blockchain architecture according to claim 2, characterized in that, in the multi-chain blockchain architecture, each node passes a consensus based on a multi-centralized alliance chain Mechanism for credit score calculation and permission classification, including: How to change the node's credit points:

In the formula: R _j is the cumulative credit score of the node; α is the weight of consensus integrity; β is the weight of transaction integrity; s _j is the node consensus contribution value, when the node completes the effective consensus in t period, then s _j The value of is 1, otherwise it is 0;

It is the value after benefit-based standardization of the node transaction integrity value. The specific calculation method is:

In the formula:

Respectively represent the maximum and minimum values of the transaction integrity value in all nodes in the t period; Nodes are divided into three levels based on the above-mentioned node credit point change method: the first-level nodes are authoritative nodes on the alliance chain; the second-level nodes are verification nodes; the third-level nodes are ordinary nodes; 30% of the institutions are first-level nodes, which take turns to create and broadcast blocks with their own private key signatures; the remaining nodes are second-level nodes, which take turns to check whether the signed blocks are legal; The default is a third-level node, which does not have the right to create blocks and verify blocks; all nodes have the right to share data; the operating results of each node will be added or subtracted according to preset conditions, when the credit score exceeds the preset Automatically adjust the grading when the permission grading boundary is reached. 4. The power trading method based on the multi-chain block chain architecture according to claim 1, wherein the registration process includes: the information chain generates a pair of keys P _a and P _b , when the user is a prosumer user, the user needs to provide the information of the distributed power generation device. On this basis, the information chain will generate the public key and private key of the distributed power generation device, and the blockchain system will The corresponding public key completes the reliable verification of the identity of the node. The system will generate a digital certificate based on the public key of the node and user information. The active nodes in the network will collect and package the information in the network and form a new block. The new block is verified by other nodes. written into the blockchain.

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