A trusted energy interaction method for source-grid-load-storage integrated energy system based on blockchain

Abstract

The present invention provides a trusted energy interaction method for a source-grid-load-storage integrated energy system based on blockchain, including the following steps: obtaining source-grid-load-storage operation data, retrieving the initial value of the variable, electric power, and thermal power cost factor at the current moment; power prediction information of thermal and electric power at the next moment, determining the change in electric power and thermal power cost factor at the next moment and issuing it; marking and signing the operation data after the optimization of the operating entity, and transmitting it to the connection node; verifying the node identity, more than half of the adjacent nodes are judged to be true, and can be written into a new block and proceed to the next step; after recalculating each variable, if the constraint conditions are met, output its own optimal power value, otherwise start the next round of iteration; each node enters a new round of the lowest cost operation state of the source-grid-load-storage system according to the new consensus output value. While ensuring the lowest operating cost and security and privacy of the subject, the present invention can effectively avoid the problem of the subject privately tampering with the subsystem parameters.

Description

Technical Field

[0001] The present invention relates to a blockchain-based energy trusted interaction method for a source-grid-load-storage integrated energy system, and belongs to the technical field of source-grid-load-storage systems. Background Art

[0002] In order to build a clean, environmentally friendly, efficient and safe modern energy system, the source-grid-load-storage system with multi-energy complementarity and coordinated utilization has become the focus of attention in recent years. Considering the multiple subjects, the large amount of source-grid-load-storage data and information, and the high information security requirements, how to achieve efficient and safe operation of all parties and maintain the privacy of energy operators is an urgent problem to be solved. Through investigation, it was found that the large amount of data and the large number of decision variables in the decision-making process of the source-grid-load-storage system caused great communication pressure and low operation efficiency. Under the pressure of information security supervision, each operator has sufficient motivation to tamper with the system parameters for their own interests and cannot resist malicious attacks.

[0003] Blockchain can be divided into three categories: public chain, private chain, and alliance chain. Alliance chain is generally initiated by multiple entities. Participating nodes must pass alliance certification. All entities can jointly maintain and manage the blockchain. It has the characteristics of fast operation speed, high scalability, strong interoperability and high security. Since the source-grid-load-storage system is composed of multiple energy operating entities, it is most appropriate to choose an alliance chain.

[0004] As a highly trustless and decentralized database, blockchain can make the computing process transparent and the information cannot be tampered with, making up for the shortcomings of decentralized energy interaction. Applying blockchain technology to the source-grid-load-storage system can not only ensure data security, but also improve the speed of multi-task parallel processing, which has practical significance for improving the safe and stable operation of the source-grid-load-storage system and information security.

[0005] In the energy information interaction and collaborative control model of source, grid, load and storage, the status of sub-models of cold, heat, electricity, steam and other systems is equal. During operation, the sub-model does not need to know the operating parameters of other sub-models, but only needs to exchange the consistency variables in the collaborative calculation process. Each operating organization of source, grid, load and storage aims to maximize its own interests and conducts collaborative interactive control of information flow and energy flow according to relevant constraints. Although the decentralized interactive model maintains the interests and privacy of all parties and realizes the decentralization of the system, it cannot guarantee the fidelity and reliability of operators, and it is difficult to verify the fairness of the decentralized operation process. Summary of the invention

[0006] The purpose of the present invention is to provide a blockchain-based energy trusted interaction method for a source-grid-load-storage integrated energy system, which can effectively avoid the problem of the subject privately tampering with subsystem parameters while ensuring the lowest operating cost and security and privacy of the subject.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A blockchain-based energy trusted interaction method for a source-grid-load-storage integrated energy system comprises the following steps:

[0009] (1) Obtain the source, grid, load and storage operation data, retrieve the initial value of the variable at the current time t, and broadcast it through the alliance chain to determine the electric power cost factor and thermal power cost factor at the current time t; in the blockchain alliance chain, it is necessary to select a node with high credibility in the thermal system and the power system as the leader node to obtain the difference between the supply and demand of thermal and electric power and determine the direction of energy flow;

[0010] (2) Obtain the power forecast information of the heat and electricity of the operating entity at the next moment, calculate the power difference of the leading node at the next moment, determine the change of the electric power cost factor and the change of the thermal power cost factor at the next moment t, and broadcast and issue them;

[0011] (3) The operators of all nodes obtain the updated changes in the electric power cost factor and the thermal power cost factor, and perform optimization for their respective operators according to the operation goal of minimizing the total system cost and the two constraints of electric power balance and thermal power balance;

[0012] (4) The operator signs and signs the optimized operation data and transmits it to the connected nodes through broadcast;

[0013] (5) Each node verifies the node identity based on the summary, public key, and key information of the previous block status. If more than half of the adjacent nodes judge it to be true, it can be written into a new block and proceed to the next step; otherwise, an error is recorded. After correcting the error, the node restarts step 1 and calculates each variable;

[0014] (6) After recalculating each variable, verify again whether the constraints are met. If so, it means that each node has reached a consensus on the energy supply allocation, and each node outputs its own optimal power value and proceeds to the next step; otherwise, proceed to step 1 to start the next round of iteration;

[0015] (7) Each node enters a new round of operation state with the lowest cost for the source-grid-load-storage system according to the new consensus output value.

[0016] Preferably, there are four types of operating entities, including: new energy power generation operators, cogeneration operators, energy storage system operators, and distribution network operators;

[0017] The new energy power generation operator adopts the maximum power generation and consumption of wind power and photovoltaic power as the cost model;

[0018] The cogeneration unit of the cogeneration operator can only operate when the load rate is higher than 30%, and the highest cogeneration operation efficiency is adopted as the cost model.

[0019] The energy storage system operator adopts the highest energy storage equipment utilization efficiency and the least number of charge and discharge times as the cost model.

[0020] The distribution network operator adopts minimization of power network losses as a cost model.

[0021] Preferably, the electrical power balance and thermal power balance constraints are as follows:

[0022] (1) Power balance constraints

[0023]

[0024] in, , , They are respectively the power generated by new energy, the power charged and discharged by energy storage, and the power generated by cogeneration of heat and power. , They are the network loss of the distribution network operator and the power load of the user.

[0025] (2) Thermal power balance constraints

[0026]

[0027] in, is the thermal power of CHP, , They are the loss of the heating network and the heating load of the user respectively.

[0028] Preferably, the operating entity's optimization method is as follows: based on the constraints of electric power balance and thermal power balance, without considering the participation in the response of the electric power demand side, when the energy supply exceeds the demand, the energy supply needs to be reduced, and the convergence direction of the energy interaction adopts a negative value throughout the time; when the energy demand exceeds the supply, the energy supply needs to be increased, and the convergence direction adopts a positive value.

[0029] The advantages of the present invention are as follows: the present invention ensures the fairness, openness, security and reliability of the distributed energy interaction process of the park-level source-grid-load-storage integrated energy system. While ensuring the lowest operating cost and security and privacy of the main body, it can effectively avoid the problem of the main body privately tampering with the subsystem parameters. It not only realizes the decentralization of the system but also improves the fairness of the system, and guarantees the interests of all parties' operating entities. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0031] Figure 1This is a schematic diagram of the source-grid-load-storage energy information operation control process based on blockchain.

[0032] Figure 2 Schematic diagram of the energy information interaction framework of the park's source-grid-load-storage energy system.

[0033] Figure 3 Schematic diagram of the source-grid-load-storage energy information operation framework based on blockchain.

[0034] Figure 4 This is a schematic diagram of the power output adjustment of the source-grid-load-storage integrated energy system without the support of blockchain technology.

[0035] Figure 5 This is a schematic diagram of the thermal power output adjustment of the source-grid-load-storage integrated energy system without the support of blockchain technology.

[0036] Figure 6 This is a schematic diagram of the power output adjustment of the source-grid-load-storage integrated energy system based on blockchain technology.

[0037] Figure 7 This is a schematic diagram of the thermal power output adjustment of the source-grid-load-storage integrated energy system supported by blockchain technology. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] A blockchain-based energy trusted interaction method for a source-grid-load-storage integrated energy system comprises the following steps:

[0040] (1) Obtain source, grid, load and storage operation data, retrieve the initial value of the variable at the current time t, and broadcast it through the alliance chain to determine the electric power cost factor and thermal power cost factor at the current time t; in the blockchain alliance chain, it is necessary to select a node with high credibility in the thermal system and the power system as the leading node to obtain the difference between the supply and demand of thermal and electric power and determine the direction of energy flow;

[0041] (2) Obtain the power forecast information of the heat and electricity of the operating entity at the next moment, calculate the power difference of the leading node at the next moment, determine the change of the electric power cost factor and the change of the thermal power cost factor at the next moment t, and broadcast and issue them;

[0042] There are four types of operating entities, including: new energy power generation operators, cogeneration operators, energy storage system operators, and distribution network operators;

[0043] The new energy power generation operator adopts the maximum power generation and consumption of wind power and photovoltaic power as the cost model;

[0044] The cogeneration unit of the cogeneration operator can only operate when the load rate is higher than 30%, and the highest cogeneration operation efficiency is adopted as the cost model.

[0045] The energy storage system operator adopts the highest energy storage equipment utilization efficiency and the least number of charge and discharge times as the cost model.

[0046] The distribution network operator adopts minimization of power network losses as a cost model.

[0047] (3) The operators of all nodes obtain the updated changes in the electric power cost factor and the thermal power cost factor, and perform optimization for their respective operators according to the operation goal of minimizing the total system cost and the two constraints of electric power balance and thermal power balance;

[0048] The electrical power balance and thermal power balance constraints are as follows:

[0049] (1) Power balance constraints

[0050]

[0051] in, , , They are respectively the power generated by new energy, the power charged and discharged by energy storage, and the power generated by cogeneration of heat and power. , They are the network loss of the distribution network operator and the power load of the user.

[0052] (2) Thermal power balance constraints

[0053]

[0054] in, is the thermal power of CHP, , They are the loss of the heating network and the heating load of the user respectively.

[0055] The optimization method of the operating entity is as follows: according to the constraints of electric power balance and thermal power balance, without considering the response of the power demand side, when the energy supply exceeds the demand, the energy supply needs to be reduced, and the convergence direction of the energy interaction adopts a negative value throughout the time; when the energy demand exceeds the supply, the energy supply needs to be increased, and the convergence direction adopts a positive value.

[0056] (4) The operator signs and signs the optimized operation data and transmits it to the connected nodes through broadcast;

[0057] (5) Each node verifies the node identity based on key information such as the summary, public key, and the status of the previous block. If more than half of the adjacent nodes judge it to be true, it can be written into a new block and proceed to the next step; otherwise, an error is recorded. After correcting the error, the node restarts step 1 and calculates each variable;

[0058] (6) After recalculating each variable, verify again whether the constraints are met. If so, it means that each node has reached a consensus on the energy supply allocation, and each node outputs its own optimal power value and proceeds to the next step; otherwise, proceed to step 1 to start the next round of iteration;

[0059] (7) Each node enters a new round of operation state with the lowest cost for the source-grid-load-storage system according to the new consensus output value.

[0060] Example

[0061] In order to verify the effectiveness of the proposed algorithm and the applicability of blockchain technology, simulation calculations are carried out through examples. The energy supply side of a typical park-level source-grid-load-storage integrated energy system contains five main nodes: wind farm, photovoltaic power station, power supply company, cogeneration unit 1, cogeneration unit 2, energy storage system, and user, which are nodes 1-7 respectively. These nodes communicate with each other and together constitute an energy supply alliance chain.

[0062] Assume that in a certain energy interaction, the power difference required by users is 50kW, the thermal power difference is 40kW, and the allowable power deviation is 0.01. Before this interactive calculation, the photovoltaic power station at node 2 tampered with the internal parameters of the system to increase its own output in order to pursue maximum benefits.

[0063] Without the support of blockchain technology, the power output of the source-grid-load-storage integrated energy system is as follows: Figure 4 , Figure 5 shown.

[0064] (1) During the power regulation process, the output of the photovoltaic power station at node 2 increased significantly from 40kW to 70kW at full load, and there was still a 20kW gap from the required power. Considering the system power balance and the requirement of not accepting power support from outside the distribution network, after the wind farm at node 1 increased from 90kW to 100kW at full load, there was still a 10kW power shortage. In order to maintain the economic and stable operation of the cogeneration unit, the energy storage system can only release 10kW of power capacity. Therefore, except for the photovoltaic power station at node 2, which obtained the maximum benefit, the interests of the wind farm, energy storage system, distribution network and other nodes were all damaged.

[0065] (2) During the thermal power regulation process, the heat and power cogeneration unit 1 at node 4 gave priority to increasing the thermal output from 60 kW to 100 kW, thus satisfying the user's thermal power difference of 100 kW. The heat and power cogeneration unit 2 at node 5 maintained the thermal power output of 50 kW unchanged, thus damaging the interests of the heat and power cogeneration unit 2 at node 5.

[0066] If the energy interaction control of the source-grid-load-storage integrated energy system based on blockchain technology is adopted, the private key digital string will change with the system parameters of the photovoltaic power station of node 2. After the subsystem parameters are tampered with, the system operation fails to verify the first broadcast. According to the smart contract, node 1 is forced to correct the parameters and run with the correct parameters. With only one more time index, this error is recorded to obtain a reasonable power allocation, successfully maintaining the fairness of energy interaction among various market entities of source-grid-load-storage. The system operation process is as follows Figure 6 , Figure 7 As shown, the main process is as follows:

[0067] (1) During the power adjustment process, the output of the photovoltaic power station at node 2 increased significantly from 40kW to 55kW at full load, and there was still a 20kW difference from the required power. After the wind farm at node 1 increased from 90kW to 100kW at full load, there was still a 15kW power shortage. In order to maintain the economic and stable operation of the cogeneration unit, and considering the operating cost of the energy storage system, the energy storage system was first used to release a controllable 5kW power capacity, and the remaining 10kW was obtained from the distribution network. The operating power of the distribution network was adjusted from 50kW to 60kW. Through this smart contract, the interests of the photovoltaic power station, wind farm, energy storage system, distribution network and other nodes have been fully considered, ensuring the transparency of the information of the entire system operation and meeting the lowest cost requirements of all parties.

[0068] (2) In the process of thermal power regulation, considering the performance differences and control costs of the units, the thermal output of cogeneration unit 1 at node 4 was first increased from 60 kW to 75 kW. At the same time, the thermal output of cogeneration unit 1 at node 5 was first increased from 90 kW to 115 kW. The two thermal power units jointly met the user's demand for a thermal power difference of 100 kW, and the interests of all parties were jointly maintained.

Claims

1. A blockchain-based energy trusted interaction method for a source-grid-load-storage integrated energy system, characterized in that: The following steps are involved: (1) Obtain the source, grid, load and storage operation data, retrieve the initial value of the variable at the current time t, and broadcast it through the alliance chain to determine the electric power cost factor and thermal power cost factor at the current time t; in the blockchain alliance chain, it is necessary to select a node with high credibility in the thermal system and the power system as the leader node to obtain the difference between the supply and demand of thermal and electric power and determine the direction of energy flow; (2) Obtain the power forecast information of the heat and electricity of the operating entity at the next moment, calculate the power difference of the leading node at the next moment, determine the change of the electric power cost factor and the change of the thermal power cost factor at the next moment t, and broadcast and issue them; (3) The operators of all nodes obtain the updated changes in the electric power cost factor and the thermal power cost factor, and perform optimization for their respective operators according to the operation goal of minimizing the total system cost and the two constraints of electric power balance and thermal power balance; (4) The operator signs and signs the optimized operation data and transmits it to the connected nodes through broadcast; (5) Each node verifies the node identity based on the summary, public key, and key information of the previous block status. If more than half of the adjacent nodes judge it to be true, it can be written into a new block and proceed to the next step; otherwise, an error is recorded. After correcting the error, the node restarts step 1 and calculates each variable; (6) After recalculating each variable, verify again whether the constraints are met. If so, it means that each node has reached a consensus on the energy supply allocation, and each node outputs its own optimal power value and proceeds to the next step; otherwise, proceed to step 1 to start the next round of iteration; (7) Each node enters a new round of lowest cost operation state for the source-grid-load-storage system according to the new consensus output value; There are four types of operating entities, including: new energy power generation operators, cogeneration operators, energy storage system operators, and distribution network operators; The new energy power generation operator adopts the maximum power generation and consumption of wind power and photovoltaic power as the cost model; The cogeneration unit of the cogeneration operator can only operate when the load rate is higher than 30%, and the highest cogeneration operation efficiency is adopted as the cost model. The energy storage system operator adopts the highest energy storage equipment utilization efficiency and the least number of charge and discharge times as the cost model. The distribution network operator adopts the minimum power network loss as the cost model; The electrical power balance and thermal power balance constraints are as follows: (1) Power balance constraints in, , , They are respectively the power generated by new energy, the power charged and discharged by energy storage, and the power generated by cogeneration of heat and power. , are the network loss of the distribution network operator and the power load of the user, respectively. (2) Thermal power balance constraints in, is the thermal power of CHP, , They are the loss of the heating network and the heating load of the user respectively.

2. The energy trusted interaction method of the source-grid-load-storage integrated energy system based on blockchain according to claim 1 is characterized in that: The optimization method of the operating entity is as follows: according to the constraints of electric power balance and thermal power balance, without considering the response of the power demand side, when the energy supply exceeds the demand, the energy supply needs to be reduced, and the convergence direction of the energy interaction adopts a negative value throughout the time; when the energy demand exceeds the supply, the energy supply needs to be increased, and the convergence direction adopts a positive value.

Images