An Electric-Thermal Market Interactive Trading Method Based on a Double-Chain Blockchain

Abstract

An electricity-heat market interactive trading method based on a double-chain blockchain, belonging to the technical field of integrated energy system operation. The present invention solves the problems that the price mechanism is not clear when the current electricity-heat load participates in market trading, the trading security is difficult to guarantee, it is difficult for trading nodes to achieve mutual trust, and it is difficult to check network constraints. Relying on the public chain, trading nodes perform end-to-end autonomous matching transactions, and then the consortium chain is used to check the network security constraints to realize the adjustment of the trading plan, so that the electricity-heat market trading achieves a balance between economy and security. Finally, by designing smart contracts, the trading information is uploaded to the chain and the trading fees are settled, promoting the consumption of new energy by electricity-heat users.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated energy system operation, and particularly relates to an electricity-heat market interactive trading method based on a double-chain blockchain. Background Art

[0002] Due to the uncertainty of new energy power generation, the situation where the planned power quantity does not match the actual power quantity often occurs, resulting in losses of deviation power quantity. Therefore, the consumption of unplanned new energy power generation has become the focus of domestic related research in recent years.

[0003] As a flexible adjustable load with time-shiftability, the electricity-heat load group has great potential in improving new energy consumption and fulfilling the responsibility of consumption weight. However, the electricity-heat user transactions are characterized by small single transaction volume and high transaction frequency. The traditional centralized scheduling method has high transaction costs and low efficiency, and it is difficult to match the characteristics of new energy power generation in terms of difference and uncertainty. Therefore, a set of decentralized trading mechanisms that are safe, mutually trustworthy, and traceable is needed to support this.

[0004] As a new application technology in the new business form of "Internet +", blockchain, with technologies such as timestamp, asymmetric encryption, and smart contracts, has characteristics such as decentralization, time traceability, autonomy, openness, and information immutability. While ensuring data security, it supports users to conduct transactions independently through the blockchain. Various types of free transactions can occur in the blockchain network, and all participating nodes in the network can check and maintain transaction information, and use the consensus algorithm to ensure the security and effectiveness of information. With the large-scale access of renewable energy to the system, blockchain has broad development prospects in scenarios such as power trading, electric vehicles, ancillary service markets, and virtual energy storage. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to provide an electricity-heat market interactive trading method based on a double-chain blockchain, which overcomes the disadvantages of low efficiency, high transaction costs of the traditional centralized scheduling method, and the difficulty of the single-chain blockchain structure in handling high concurrent throughput, and solves the problems such as unclear price mechanism, difficult to guarantee transaction security, difficult to achieve mutual trust among transaction nodes, and difficult to check network constraints when the current electricity-heat load participates in market transactions.

[0006] An electricity-heat market interactive trading method based on a double-chain blockchain, characterized by: including the following steps, and the following steps are carried out sequentially,

[0007] Step 1: Construct a public chain and a consortium chain

[0008] Deploy a dual-chain blockchain electro-thermal market interactive trading structure that couples a public chain and a consortium chain. The public chain is used to support on-chain trading nodes to negotiate and achieve end-to-end transactions, and the consortium chain is used to store the physical information of the grid structure to achieve distributed security verification of the trading consensus scheme;

[0009] Step 2. Modeling within the public chain

[0010] Differentially model the decision-making at the user side and the power generation enterprise side for the electricity consumption demands of electro-thermal users and the power generation plans of each new energy power generation enterprise. At the electro-thermal user side, model with the goal of maximizing the self-benefit of the electro-thermal user, with the cross-network fee cost proposed by the electro-thermal user and the electricity quantity purchased by the user as constraints; at the power generation enterprise side, establish a photovoltaic output model and a micro gas turbine cost model, and model and make decisions with the goal of minimizing the overall power generation cost and maximizing the benefit, meeting the system power flow constraints and its own electricity sales capacity constraints;

[0011] Step 3. Transaction verification

[0012] The electro-thermal user is the buyer, and the power generation enterprise side is the seller. Solve the respective optimization models of the buyer and the seller through the Lagrange multiplier method, update the trading quotes and trading volumes through on-chain broadcasting for interactive gaming. When the system convergence criterion is met, form trading matching information, realize data interaction between the public chain and the consortium chain through the use of cross-chain technology, perform security verification through the consortium chain, and formulate a smart contract to achieve transaction settlement after passing the verification, completing the interactive consumption between the new energy power station and the electro-thermal load users.

[0013] The on-chain trading nodes in the public chain in Step 1 include new energy power generation enterprises and electro-thermal users.

[0014] The execution process of the dual-chain blockchain electro-thermal market interactive trading structure that couples the public chain and the consortium chain in Step 1 is written into a smart contract. The smart contract is deployed on the blockchain that couples the public chain and the consortium chain. The smart contract includes 6 types of contract processes, namely no contract execution, contract interaction, contract verification, contract signing, contract execution, and deviation calculation.

[0015] In Step 2, the electro-thermal user side models with the goal of maximizing the self-benefit of the electro-thermal user. The optimization decision-making model of electro-thermal user i at time t is:

[0016]

[0017]

[0018] P g,i,min ≤P g,i ≤P g,i,max

[0019]

[0020] Where: P i,j and P grid,i are the transaction power quantities of the electricity - heat user i, the new - energy power generation enterprise j, and the main grid respectively; λ i,j and λ grid,i are the transaction prices. Among them, the transmission network charges generated by transmitting electric energy are added to the transaction prices of the corresponding buyers and sellers according to the distribution network voltage level and transaction policies. P d,i is the load quantity of the electricity - heat user, and λ d,i is the electricity price. P g,i is the adjustable load quantity of the electricity - heat user; C g,i (·) is the cost function; P g,i,max and P g,i,min are the maximum and minimum quantities of the adjustable load of the electricity - heat user respectively; N is the total number of on - chain transaction nodes, which is the sum of electricity - heat users and new - energy power generation enterprises.

[0021] In the second step, the photovoltaic output model and the micro - gas turbine cost model established at the power generation enterprise side are as follows.

[0022] The photovoltaic output cost model is:

[0023]

[0024] Where, is the power generation cost unit price of the power generation enterprise j, C j,de is the equipment cost of the power generation enterprise j, P j,GE is the annual power generation of the photovoltaic system, T j,LS is the service life of the photovoltaic system;

[0025] The cost model of the micro - gas turbine is:

[0026]

[0027]

[0028] Where, is the output of the micro - gas turbine of the power generation enterprise j during the transaction period t; is the cost of the micro - gas turbine during the transaction period t, and a, b, d are the coefficients related to the gas turbine cost; and are the upper and lower limits of the gas turbine output power during this period;

[0029] Then the decision - making model of the new - energy power generation enterprise is:

[0030]

[0031]

[0032]

[0033]

[0034] The safety verification method of the alliance chain in the third step is as follows:

[0035] 1. If the transaction result does not meet the safety verification, the transaction plan shall be proportionally reduced according to the proportion of the transaction volume until the system passes the safety verification;

[0036] 2. If the transaction result meets the safety verification, a signal of executable transaction shall be sent to each node of the public chain, and each transaction node of the public chain shall settle according to the transaction plan.

[0037] The transaction verification result is divided into end-to-end transaction result and main network transaction result, including the two-way power flow distribution of the line and the power inflow and outflow values of each node.

[0038]

[0039] In the formula: and are the transaction volume between power generation enterprise i and electro-thermal user j or the transaction power volume between electro-thermal user and the main network after reaching the consensus equilibrium point;

[0040] The power P of each transaction node of the distribution network j is:

[0041]

[0042] The line power flow constraint is:

[0043] -P l,max ≤P l ≤P l,max l = 1, 2, L, N

[0044] If the transaction result meets the safety verification, it shall be executed according to the interaction result of both parties of the transaction. If it does not meet the safety verification, the transaction plan shall be proportionally reduced according to the proportion of the transaction volume until the system passes the safety verification. The reduction amount of each transaction is:

[0045]

[0046] In the formula: P r is the reduction amount of each transaction, P e is the over-limit amount of the line power flow, P deal is the original planned transaction volume, P all is all the transaction volumes on this line; the verified transaction volume P deal,re is:

[0047] Pdeal,re = P deal - P r 。

[0048] Through the above design, the present invention can bring the following beneficial effects: An electro-thermal market interactive trading method based on a double-chain blockchain solves problems such as unclear price mechanisms, difficult-to-guarantee trading security, difficult-to-achieve mutual trust among trading nodes, and difficult-to-check network constraints when current electro-thermal loads participate in market trading. Relying on the public chain, trading nodes perform end-to-end autonomous matching transactions, and then through the consortium chain, network security constraints are checked to adjust the trading plan, achieving a balance between economy and security in electro-thermal market trading. Finally, by designing smart contracts, the trading information is uploaded to the chain and the trading fees are settled, promoting the consumption of new energy by electro-thermal users. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention will be further described below in conjunction with the drawings and specific embodiments:

[0050] Figure 1 It is a schematic block diagram of the coupled operation of the public chain and the consortium chain of an electro-thermal market interactive trading method based on a double-chain blockchain according to the present invention.

[0051] Figure 2 It is a schematic diagram of the operation mechanism of a smart contract of an electro-thermal market interactive trading method based on a double-chain blockchain according to the present invention. SPECIFIC EMBODIMENTS

[0052] A method for electric-thermal market interactive trading based on a dual-chain blockchain. In the trading architecture of the dual-chain blockchain for electric-thermal market interactive trading with the coupling of a public chain and a consortium chain, the trading information flow and the power physical information flow are separately deployed. The public chain is responsible for supporting the autonomous game negotiation of trading nodes on the chain to achieve end-to-end trading. Each block in the consortium chain only stores the physical information of the grid framework structure to realize the distributed security check of the trading consensus scheme. The trading nodes on the chain include new energy power generation enterprises and electric-thermal users. Differentiated modeling of decision-making is carried out for the user side and the power generation enterprise side according to the different electricity consumption demands of electric-thermal users and the power generation plans of different new energy power generation enterprises. The electric-thermal user side is modeled with the goal of maximizing the self-benefit of the electric-thermal user, and different transmission fees and user electricity purchase quantity constraints are proposed for different electric-thermal users. The power generation enterprise side establishes a photovoltaic output model and a micro gas turbine cost model, and makes modeling decisions with the goal of minimizing the overall power generation cost and maximizing the benefit, while meeting the system power flow constraint and its own electricity sales capacity constraint. The buyer and the seller solve their respective optimization models through the Lagrange multiplier method, and conduct interactive games by updating the trading quotes and trading volumes through on-chain broadcasting. When the system convergence criterion is met, trading matching information is formed, and then data interaction between the public trading chain and the consortium verification chain is realized by using cross-chain technology, and security verification is carried out through the consortium chain. If the security verification is not satisfied, the trading plan is proportionally reduced according to the proportion of the trading volume until the system passes the security verification. If the security verification is satisfied, a signal of executable trading is sent to each node of the public chain, and each trading node of the public chain settles according to the trading plan, and realizes trading settlement by formulating smart contracts to address the interactive consumption problem between new energy power stations and numerous electric-thermal load users.

[0053] The design pattern of the smart contract involved in the trading process is as follows:

[0054] In the patent, the trading execution process between new energy power generation enterprises and electric-thermal users is written into a smart contract, and the smart contract is deployed on the blockchain with the coupling of a public chain and a consortium chain. There are 6 contract processes in the smart contract, including contract execution without contract, contract interaction, contract verification, contract signing, contract execution, and deviation calculation assessment.

[0055] The smart contract packages and stores the trading information in the interactive process into the block bill, and calculates the block reward according to the trading volume and trading price. In order to prevent some electric-thermal users and new energy power generation enterprises from submitting false electricity purchase and sales information and not responding for a long time, the smart contract ensures the normal interaction of each trading node on the chain by formulating corresponding assessment mechanisms.

[0056] The intelligent contract visualization interface includes a block header and a block body. The block body contains information such as the parent hash value, timestamp, transaction result, block address, and difficulty coefficient. New energy power generation enterprises and electricity-heat users can query transaction information and consumption volume results by inputting the block address and timestamp.

[0057] Specifically, as Figure 1 shown, in the public chain, the trading nodes participating in the transaction select several accounting nodes through a competitive election method to record the implemented transactions. At the same time, the verification nodes in the consortium chain verify and adjust the transaction results that reach a consensus. Through the cooperation of the accounting nodes and verification nodes, a dual-chain electricity-heat load trading operation mechanism that couples the public chain and the consortium chain is formed. First, the electricity-heat users and new energy power generation enterprises on the chain interact. In each transaction stage, each electricity-heat user aims to maximize its own benefits and optimizes and decides its own power purchase and sale situation. The optimization decision model of electricity-heat user i at time t is:

[0058]

[0059]

[0060] P g,i,min ≤P g,i ≤P g,i,max (3)

[0061]

[0062] In the formula: P i,j and P grid,i are the transaction power quantities of electricity-heat user i, new energy power generation enterprise j, and the main grid respectively; λ i,j and λ grid,i are the transaction prices. Among them, the transmission network fee generated by transmitting electric energy is added to the transaction prices of the corresponding buyers and sellers according to the distribution network voltage level and transaction policy. P d,i is the load quantity of the electricity-heat user, λ d,i is the electricity price, P g,i is the adjustable load quantity of the electricity-heat user; C g,i (·) is the cost function; P g,i,max and P g,i,min are the maximum and minimum quantities of the adjustable load of the electricity-heat user respectively; N is the total number of trading nodes on the chain (the sum of electricity-heat users and new energy power generation enterprises).

[0063] The optimization decision model of new energy power generation enterprise j is:

[0064] PV photovoltaic model:

[0065] For each new energy power generation enterprise, if the j-th new energy power generation enterprise has a photovoltaic system (PV), its output model is:

[0066]

[0067] In the formula, is the actual power of the PV output of the j-th new energy power generation enterprise in trading period t, is the maximum value of the predicted PV output in trading period t.

[0068] The PV output cost model is:

[0069]

[0070] In the formula, is the power generation cost unit price of power generation enterprise j, C j,de is the equipment cost of power generation enterprise j, P j,GE is the annual power generation of the PV system, T j,LS is the service life of the PV system.

[0071] Micro gas turbine model:

[0072] The cost model of the micro gas turbine is:

[0073]

[0074]

[0075] In the formula, is the output of the micro gas turbine of power generation enterprise j within trading period t; is the cost of the micro gas turbine within trading period t, and a, b, d are coefficients related to the gas turbine cost; and are the upper and lower limits of the gas turbine output power within this period.

[0076] Then the decision-making model of the new energy power generation enterprise is:

[0077]

[0078]

[0079]

[0080]

[0081] The above optimization decision-making model is solved by the Lagrange multiplier method. Each electricity-heat user and new energy power generation enterprise uploads the optimized purchase and sale power and purchase and sale prices to the corresponding block in the public chain transaction node. The accounting node updates the transaction information and the block, realizing the decentralization of all transaction consensus information in the public chain. Then each transaction node reads the historical transaction information and the updated strategy information of each transaction node by inputting the timestamp and block address, reasonably adjusts its own power purchase and sale strategy, and conducts multiple rounds of interaction until the buyer and seller reach a consensus equilibrium point x * 。

[0082] After reaching the transaction consensus, it is necessary to check the network constraints. Therefore, it is proposed to check the network constraints through the checking nodes in the consortium chain to achieve fair verification and reasonable adjustment of the transaction plan. The power grid dispatching center, new energy power generation enterprises, and each electricity-heat user can all be used as nodes in the consortium chain. The checking nodes in the consortium chain are selected by voting of all nodes and are comprehensively determined according to the transaction credit of each node.

[0083] The checking nodes will conduct dynamic and static checks on the system. Among them, static checks mainly consider the upper and lower bounds of line transmission capacity, and dynamic checks mainly consider transmission power limits.

[0084] The transaction checking results are divided into end-to-end transaction results and main network transaction results, including the two-way power flow distribution of the line and the power values flowing in and out of each node, that is:

[0085]

[0086] In the formula: and are the trading volume between power generation enterprise i and electricity-heat user j or the trading power volume of the electricity-heat user's transaction with the main network after reaching the consensus equilibrium point.

[0087] The power P of each transaction node in the distribution network j is:

[0088]

[0089] The line power flow constraint is:

[0090] -P l,max ≤P l ≤P l,max l = 1, 2, L, N (15)

[0091] If the transaction result meets the security check, it will be executed according to the interaction result of the buyer and seller. If it does not meet the security check, the transaction plan will be proportionally reduced according to the proportion of the trading volume until the system passes the security check. The reduction amount of each transaction is:

[0092]

[0093] Where: P r is the reduction amount of each transaction, P e is the over-limit amount of the power flow on this line, P deal is the originally planned trading volume,

[0094] P all is all the trading volumes on this line. The verified trading volume P deal,re is:

[0095] P deal,re = P deal - P r (17)

[0096] In order to automatically execute the interactive decision-making and security verification of each trading node, the interaction process between the public chain and the consortium chain is written into a smart contract. When certain triggering conditions are met, automatic settlement is automatically executed through the smart contract to achieve traceability of transaction information. There are 6 types of contract processes in the smart contract, namely contract execution without contract, contract interaction, contract verification, contract signing, contract execution, and deviation assessment. Its operation mechanism is as Figure 2 shown.

[0097] The triggering conditions of the smart contract can be set to trigger at a fixed time. For example, contract negotiation and transaction plan confirmation start at 11:00 before the day-ahead. The process includes the trading volume, trading period, trading price, etc. that are interacted between the buyer and the seller. At 16:00 before the day-ahead, the consortium chain security verification of the publicized results of the interaction starts. At 18:00 before the day-ahead, the release of the verification results and the adjustment of the transaction plan start. At 20:00 before the day-ahead, contract signing is carried out. On the trading day, transactions are carried out according to the day-ahead trading contract, and the capital flow is automatically realized through the smart contract.

[0098] After the day-ahead trading is completed, due to the deviation of the power generation of new energy power generation enterprises, the deviation of the power is therefore assessed. The deviation of the power is assessed at 12:00 after the trading day. The deviation electricity fee is calculated based on the actual trading electricity volume and the planned trading electricity volume, and refunded to the electricity-heat users who bought the electricity. By setting the deviation assessment coefficient, a certain degree of penalty is imposed on the deviated part of the electricity volume. The deviated electricity volume that appears during the trading process is filled by trading with the superior power grid. At the same time, in order to prevent some electricity-heat users and new energy power generation enterprises from submitting false electricity purchase and sale information and the situation of not responding for a long time, the smart contract formulates corresponding assessment mechanisms to ensure normal interaction of each trading node on the chain.

[0099] The visual interface of the smart contract includes the block header and the block body. Among them, the block body includes information such as the parent hash value, timestamp, transaction result, block address, and difficulty coefficient. New energy power generation enterprises and electricity-heat users can query the transaction information and the consumption volume results by inputting the block address and timestamp.

Claims

1. A method for electric-thermal market interactive trading based on a double-chain blockchain, characterized in that: It includes the following steps, which are carried out sequentially, Step 1: Construct a public chain and a consortium chain Deploy a dual-chain blockchain electro-thermal market interactive trading structure coupled with the public chain and the consortium chain. The public chain is used to support on-chain trading nodes to negotiate and achieve end-to-end transactions, and the consortium chain is used to store the physical information of the grid structure to achieve distributed security verification of the trading consensus scheme; Step 2: Modeling within the public chain Differentiated modeling of decision-making at the user side and the power generation enterprise side is carried out for the electricity consumption needs of electro-thermal users and the power generation plans of each new energy power generation enterprise. At the electro-thermal user side, modeling is carried out with the goal of maximizing the own benefits of electro-thermal users, with the cross-network fee cost proposed by electro-thermal users and the electricity quantity purchased by users as constraints; at the power generation enterprise side, a photovoltaic output model and a micro gas turbine cost model are established, and modeling decisions are made with the goal of minimizing the overall power generation cost and maximizing the benefits, meeting the system power flow constraints and the constraints of its own power sales capacity; Step 3: Transaction verification The electro-thermal user is the buyer, and the power generation enterprise side is the seller. The respective optimization models of the buyer and the seller are solved by the Lagrange multiplier method, and interactive games are carried out by updating the trading quotes and trading volumes through on-chain broadcasting. When the system convergence criterion is met, transaction matching information is formed. Data interaction between the public chain and the consortium chain is realized by using cross-chain technology, and security verification is carried out through the consortium chain. After the verification passes, a smart contract is formulated to realize transaction settlement, and the interactive consumption between the new energy power station and the electro-thermal load users is completed; The method for the consortium chain to carry out security verification in Step 3 is as follows 1. If the transaction result does not meet the security verification, the transaction plan is proportionally reduced according to the proportion of the trading volume until the system passes the security verification; 2. If the transaction result meets the security verification, a signal of executable transaction is sent to each node of the public chain, and each trading node of the public chain settles according to the transaction plan; The transaction verification results are divided into end-to-end transaction results and transaction results with the main grid, including the two-way power flow distribution of the line and the inflow and outflow power values of each node, Wherein: and is the transaction volume between power generation enterprise i and electric-heat user j or the transaction power volume of the electric-heat user trading with the main grid after reaching the consensus equilibrium point; The power P of each trading node in the distribution network j is as follows: The line power flow constraint is: -P l,max ≤P l ≤P l,max l = 1, 2, …, N If the transaction result meets the security verification, it is executed according to the interaction result of both parties of the transaction. If it does not meet the security verification, the transaction plan is proportionally reduced according to the proportion of the trading volume until the system passes the security verification; the reduction amount of each transaction is: Where: P r is the reduction amount of each transaction, P e is the over-limit amount of the line power flow, P deal is the originally planned transaction volume, P all is all the transaction volumes on this line; the verified transaction volume P deal,re is: P deal,re = P deal -P r 。 2. The electro-thermal market interactive trading method based on a double-chain blockchain according to claim 1, characterized in that: The on-chain trading nodes of the public chain in Step 1 include new energy power generation enterprises and electro-thermal users.

3. The electro-thermal market interaction trading method based on a double-chain blockchain according to claim 1, wherein: The execution process of the dual-chain blockchain electro-thermal market interactive trading structure coupled with the public chain and the consortium chain in Step 1 is written into a smart contract. The smart contract is deployed on the blockchain coupled with the public chain and the consortium chain. There are 6 types of contract processes in the smart contract, namely no contract execution, contract interaction, contract verification, contract signing, contract execution, and deviation calculation.

4. A method for electro-thermal market interaction trading based on a double-chain blockchain according to claim 1, characterized in that: In Step 2, modeling is carried out at the electro-thermal user side with the goal of maximizing the own benefits of electro-thermal users. The optimization decision model of electro-thermal user i at time t is: P g,i,min ≤P g,i ≤P g,i,max Where: P i,j and P grid,i are the transaction power quantities of the electric-heat user i, the new energy power generation enterprise j, and the main grid respectively; λ i,j and λ grid,i are the transaction prices. Among them, the transmission network charges generated by transmitting electric energy are added to the transaction prices of the corresponding buyers and sellers according to the distribution network voltage level and transaction policies. P d,i is the load quantity of the electric-heat user, λ d,i is the electricity price, P g,i is the adjustable load quantity of the electric-heat user; C g,i (·) is the cost function; P g,i,max and P g,i,min are the maximum and minimum quantities of the adjustable load of the electric-heat user respectively; N is the total number of on-chain transaction nodes, which is the sum of the electric-heat users and the new energy power generation enterprises.

5. The electro-thermal market interactive trading method based on a double-chain blockchain according to claim 1, characterized in that: In Step 2, the establishment of the photovoltaic output model and the micro gas turbine cost model at the power generation enterprise side is as follows The photovoltaic output cost model is: wherein, is the unit power generation cost of power generation enterprise j, C j,de is the equipment cost of power generation enterprise j, P j,GE is the annual power generation of the PV system, T j,LS is the service life of the PV system; The cost model of the micro gas turbine is: In the formula, is the output of the micro gas turbine of power generation enterprise j during trading period t; is the cost of the micro gas turbine during trading period t, and a, b, and d are coefficients related to the cost of the gas turbine; and are the upper and lower limits of the output power of the gas turbine during this period; Then the decision-making model of the new energy power generation enterprise is:

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