A virtual power plant trading mechanism based on the main-side chain structure

Abstract

The present invention discloses a virtual power plant trading mechanism based on a main-side chain structure, which relates to the technical field of power industry management and includes the following steps: 1. Pre-trading stage; 2. Side chain trading stage, where the aggregator nodes in the side chain include fully agent-based aggregators and self-trading aggregators; the fully agent-based aggregator realizes internal pricing according to internal load prediction information and power generation prediction information, and the distributed resource entities inside respond to the price signals of the fully agent-based aggregator through smart meters; the side chain trading participated by the self-trading aggregator conducts continuous double auction trading; 3. Main chain trading stage, when there is a power surplus or power shortage after the trading in the side chain is completed, participate in the main chain trading and conduct continuous double auction trading; 4. Power delivery stage; 5. Settlement stage. The present invention provides a virtual power plant trading mechanism with low cost and high security to adapt to the development trend of the emergence of a large number of distributed resources.

Description

Technical Field

[0001] The present invention relates to the technical field of power industry management, and in particular to a virtual power plant trading mechanism based on a main-side chain structure. Background Art

[0002] With the advancement of the dual-carbon goal process, renewable new energy gradually replaces traditional fossil energy, and the energy structure system is shifting towards cleaner and lower-carbon directions. However, due to the characteristics of sparse spatial distribution, small individual output volume, and random and uncertain output of renewable new energy, the flexible resources of the power system are stretched in aspects such as frequency modulation and voltage regulation. As a management method for aggregating and coordinating distributed resources, a virtual power plant can reduce the volatility of distributed resource output as much as possible and ensure the stable operation of the power system.

[0003] At present, there have been many studies on the trading and scheduling of virtual power plants. The literature "Operating Mode of Virtual Power Plant Considering Peak Regulation Ancillary Services" Electric Power Automation Equipment, 2021, and the literature "Deep Peak Regulation Market Mechanism and Clearing Model Considering the Participation of Virtual Power Plants" Global Energy Interconnection, 2020, studied the trading models of virtual power plants participating in the peak regulation ancillary service market and the deep peak regulation market. However, they still centrally coordinate and manage distributed resources, facing problems such as high operating costs of central institutions, trust issues among multiple trading parties, data security and privacy issues, etc. The literature "Dynamic Game of Electricity Price and Electricity Quantity in Microgrid Power Market Based on Blockchain" Automation of Electric Power Systems, 2021, and the literature "Direct Trading Mode and Strategy of Microgrid Based on Blockchain and Continuous Double Auction Mechanism" Proceedings of the Chinese Society of Electrical Engineering, 2018, respectively studied the microgrid trading mechanisms based on the dynamic game of electricity price and electricity quantity and the continuous double auction mechanism on the basis of blockchain technology. However, they are all difficult to adapt to the future development trend of the emergence of a large number of distributed resources.

[0004] Therefore, the technical personnel in this field are committed to developing a low-cost and high-security virtual power plant trading mechanism to adapt to the future development trend of the emergence of a large number of distributed resources. Summary of the Invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is: how to develop a low-cost and high-security virtual power plant trading mechanism to adapt to the future development trend of the emergence of a large number of distributed resources.

[0006] To achieve the above object, the present invention provides a virtual power plant trading mechanism based on a main-side chain structure, including the following steps:

[0007] Step 1. Pre - transaction stage: The virtual power plant node publishes the grid power purchase and sale electricity prices as the upper and lower bounds of the transaction declaration electricity price. The node publishes the transaction electricity quantity limit according to the line structure and the node distribution location. The upper and lower bounds of the declaration electricity price and the transaction electricity quantity limit are stored in the main - chain temporary block for nodes to view;

[0008] Step 2. Side - chain transaction stage: The aggregator nodes in the side - chain include fully - agent aggregators and self - trading aggregators;

[0009] The fully - agent aggregator realizes internal pricing according to the internal load prediction information and power generation prediction information. The internal distributed resource entities respond to the price signals of the fully - agent aggregator through smart meters. The electricity quantity information of the internal distributed resource entities in response is temporarily stored in the side - chain temporary block. The fully - agent aggregator integrates the responded electricity quantity to participate in the main - chain transaction;

[0010] The side - chain transaction participated by the self - trading aggregator conducts a continuous two - way auction transaction by publishing the electricity quantity and the electricity selling price or electricity purchase price information of the internal distributed resource entities, calls the smart contract, arranges the declaration information in sequence according to the price, credit value, and electricity quantity attributes, and completes the transaction matching. The transaction - completed electricity quantity and electricity price information of the internal distributed resource entities are stored in the side - chain temporary block;

[0011] Step 3. Main - chain transaction stage: When there is an electricity surplus or electricity shortage after the transaction in the side - chain, it participates in the main - chain transaction, including the following steps:

[0012] Each node in the main - chain declares the electricity quantity and the electricity selling price or electricity purchase price, and then calls the smart contract to execute the continuous two - way auction transaction on the main - chain to form a preliminary auction result;

[0013] The preliminary auction result is stored in the main - chain temporary block. The nodes conduct safety checking work. After obtaining the technical confirmation of the nodes, a final transaction result is formed and stored in the main - chain formal block;

[0014] Step 4. Power delivery stage: Each entity in the main - chain and side - chain executes power supply and consumption according to the transaction result, and the smart meter records the actual electricity delivery quantity;

[0015] Step 5. Settlement stage: Settle the bill according to the actual electricity delivery information in the smart meter. After the electricity quantity settlement is completed, the actual delivery quantity is stored in the main - chain formal block, the credit value of the node is updated, and the data information in the main - chain temporary block is released.

[0016] In a preferred embodiment of the present invention, in step 2, the credit value R(t) includes the long - term credit value R L (t) determined according to the node credit evaluation mechanism, and the short - term credit value RS (t), the short - term credit value R S (t) is calculated as follows:

[0017]

[0018] Among them, ΔE(t) represents the deviation between the transaction power at time t and the actual power consumption; ΔE min represents the deviation compliance range. When the deviation is less than ΔE min , the node credit value is 1; ΔE max represents the maximum acceptable deviation range. When the deviation is greater than ΔE max , the node credit value is 0; K is the deviation coefficient, satisfying:

[0019] The long - term credit value R L (t) is calculated as follows:

[0020]

[0021] The credit value calculation formula is as follows:

[0022]

[0023] The long - term credit value R L (t) reflects the performance of the node in two consecutive transactions. If the credit value of this transaction is lower than that of the previous transaction, a part of the credit value will be deducted as a penalty based on the credit value of this transaction; if the credit value of this transaction is higher than that of the previous transaction, a reward will be given based on the credit value of this transaction.

[0024] In a preferred embodiment of the present invention, the selling electricity price λ s and the purchasing electricity price λ b can be adjusted within the upper and lower limits of the declared electricity price according to the power generation cost and electricity consumption utility. The specific formula is as follows:

[0025]

[0026] Where r b,j , r s,i represent the profits that the node wants to obtain, k s,i is the power generation cost, and k b,j is the electricity consumption utility.

[0027] In a preferred embodiment of the present invention, when the selling party closes a deal at the selling electricity price, the profit calculation formula is:

[0028] I s,i =(λ s,i - k s,i )ΔPi = [(1 + r s,i )k s,i - k s,i ΔP i = r s,i k s,i ΔP i

[0029] Wherein, ΔP i is the transaction electricity volume.

[0030] In a preferred embodiment of the present invention, the continuous two-way auction transaction includes the following steps:

[0031] S1. The power seller and the power buyer declare the electricity volume and the selling electricity price or the buying electricity price for the transaction within the specified time;

[0032] S2. Arrange the declared information of the power seller and the power buyer in the order of electricity price - credit value;

[0033] S3. Match according to the lowest price of the power seller and the highest price of the power buyer;

[0034] S4. If the buying electricity price of the power buyer is not lower than the selling electricity price of the power seller, the transaction is successful. If the buying electricity price of the power buyer is lower than the selling electricity price of the power seller, the transaction fails and this round of transaction ends;

[0035] S5. If there is only electricity volume to be traded on one side of the power seller or the power buyer, or the number of trading rounds exceeds the preset maximum number of trading rounds, it is determined that the transaction ends; otherwise, the power buyer and the power seller update the quotation strategy by adjusting the profit margin, re - price, and execute step S1.

[0036] In a preferred embodiment of the present invention, in step S5, the strategy for updating the quotation is carried out through the following formula:

[0037] Selling electricity price:

[0038] Buying electricity price:

[0039] Wherein, m represents the maximum number of trading rounds, h represents the current trading round, and h ∈ [1, m - 1].

[0040] In a preferred embodiment of the present invention, the strategy for updating the quotation is to divide the price declared in the first round and the marginal cost into m intervals according to the maximum number of trading rounds, where m is a positive integer greater than 0. When a new transaction fails, the quotation is adjusted by giving concessions until it is adjusted to the marginal cost.

[0041] In a preferred embodiment of the present invention, after the power seller and the power buyer are successfully matched to complete the transaction matching, the price settlement is carried out according to the following formula:

[0042]

[0043] In a preferred embodiment of the present invention, if after the end of the maximum number of trading rounds, there are still cases where the electricity purchase price of some electricity purchasers is lower than the electricity selling price of the electricity sellers, then the transaction matching is carried out according to the average value of the marginal costs of both parties.

[0044] The beneficial effects of the present invention are as follows:

[0045] 1. The present invention adopts a virtual power plant trading model based on blockchain technology, and uses the characteristics of blockchain such as decentralization, openness and transparency, and data immutability to improve the problems in the traditional power trading mode.

[0046] 2. The present invention combines the existing physical information framework and development trend of the smart grid, constructs a virtual power plant trading system suitable for the needs of a large number of distributed and trusted transactions, designs a blockchain deployment method with a multi-chain structure, and studies the trading mechanism under the main chain and side chain structures.

[0047] 3. It provides a virtual power plant trading mechanism with low cost and high security to adapt to the development trend of the emergence of a large number of distributed resources.

[0048] The following will further illustrate the concept, specific structure and technical effects of the present invention with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a virtual power plant trading flow chart based on the main-chain and side-chain structure of a preferred embodiment of the present invention;

[0050] Figure 2 is a schematic diagram of the distributed resource layer in an embodiment of the present invention;

[0051] Figure 3 is a schematic diagram of a multi-agent system in an embodiment of the present invention;

[0052] Figure 4 is a marginal cost curve graph of the electricity seller in an embodiment of the present invention;

[0053] Figure 5 is a marginal cost curve graph of the electricity purchaser in an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] The following introduces multiple preferred embodiments of the present invention with reference to the accompanying drawings of the specification, so as to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0055] In the drawings, components having the same structure are denoted by the same reference numerals, and components having similar structures or functions everywhere are denoted by similar reference numerals. The dimensions and thicknesses of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustration clearer, the thicknesses of the components are appropriately exaggerated in some places in the drawings.

[0056] A large number of distributed resources are aggregated and coordinated inside the virtual power plant. In the internal structure of the traditional virtual power plant, the virtual power plant operator can remotely control the distributed resources. However, with the continuous emergence of a large number of distributed flexible resources, the virtual power plant operator will need to process a high-dimensional optimization model when dispatching electric energy, resulting in a reduction in computing efficiency. Therefore, as Figure 2 shown, according to the existing multi-agent multi-level hierarchical physical system and its adapted information architecture, the inside of the virtual power plant is divided into a resource aggregation layer and a distributed resource layer according to the size of the agent capacity and the form of market agency.

[0057] The distributed resource layer is used to coordinate market entities such as small-scale distributed power sources and residential users; the resource aggregation layer is used to coordinate market entities such as aggregators, large-capacity power sources, and large-scale energy storage. The aggregators in the resource aggregation layer include load aggregators, electric vehicle aggregators, integrated energy service providers, etc., and usually include one or several distributed resources. However, it does not mean that all aggregators include the distributed resource layer. Only when there is transaction interaction and capital flow between the upper and lower levels can they be considered two different levels. For example, a microgrid industrial park invested and constructed by the same developer, which includes distributed resources such as photovoltaic, wind power, and controllable loads, does not include the distributed resource layer because it has the same interest entity; a load aggregator that aggregates the load of residents in a jurisdiction and the residential users do not belong to the same interest entity and there is capital transaction, so it includes the distributed resource layer.

[0058] As Figure 3 shown, the market level division inside the virtual power plant matches the hierarchical control of the multi-agent system. Therefore, a multi-agent system is deployed in the virtual power plant to implement a flat trading architecture of the virtual power plant based on multi-agents. For the convenience of description, the entities in the resource aggregation layer such as the above-mentioned aggregators, large-capacity power sources, and large-scale energy storage are collectively referred to as aggregators. To facilitate the aggregators to participate in market transactions, a virtual trading agent is deployed at the virtual power plant operator to provide a trading platform for the aggregators. In the platform constructed by the virtual trading agent, each aggregator executes the auction decision function to reach transactions with each other.

[0059] Transaction agents are deployed in each aggregator to implement the bidding decision function of the virtual power plant. Aggregators can be further divided into fully agent-based aggregators and self-trading aggregators according to their internal distributed resource entities. For example, load aggregators mainly aggregating residential loads cannot directly participate in transactions due to the limited computing power of the smart meters equipped by residential users. In this case, residential users sign contracts with aggregators, and the aggregators act as agents to achieve flexible internal pricing (fully agent-based aggregators); integrated energy service providers aggregating various distributed energy sources contain many distributed resource entities with the ability to quote prices. In this case, the aggregator does not interfere with the internal transaction results and only participates in market transactions using the internal transaction results (self-trading aggregators).

[0060] At the distributed resource layer, each decentralized interest entity is equipped with devices such as smart meters at the terminal. In the distributed resource layer under the fully agent-based aggregator, the transaction agent is used to respond to the price signal of the aggregator, timely adjust its own power generation and consumption behavior, and record the capital flow record with the aggregator; in the distributed resource layer under the self-bidding aggregator, the transaction agent also has the function of independently declaring the transaction electricity volume and price.

[0061] The virtual power plant operator only provides a trading platform for aggregators in the market transaction, does not interfere with the bidding decision of internal aggregators, and only serves as a medium for internal aggregator transactions. Therefore, the virtual power plant operator and the aggregator are equal in status, realizing the flat trading of the virtual power plant.

[0062] In the flat trading system of the virtual power plant based on the multi-agent system, in order to adapt to the multi-level virtual power plant market mechanism, a blockchain in the form of a main side chain is constructed. The main chain is deployed at the resource aggregation layer, and all aggregators can apply to join the blockchain to participate in energy and service transactions. On the one hand, the main node realizes basic functions such as executing the bidding decision of the aggregator agent, confirming the transaction order information, and recording the capital flow. On the other hand, it should realize the distributed database function of multi-point parallel accounting of the blockchain to ensure the security and immutability of information transaction data in the blockchain. And, in order to ensure the security and reliability of energy transactions, a special form of consortium chain is adopted on the main chain side. It is required that aggregators participating in the transaction structure of the virtual power plant must have a certain communication ability and credit foundation.

[0063] To ensure that aggregators have the above qualifications, supervision nodes are added to the main-side chain governance structure and are set in virtual power plant operators and power grid companies. Among them, the virtual power plant operator node, on the one hand, executes the functions of the above-mentioned virtual transaction agent. At the same time, it should also execute some functions of the regulation agent, such as the identity authentication of the aggregator node, the adjustment of the transaction order after security check, etc. The functions of the power grid company node include supervising the virtual power plant transaction process, providing power security check, collecting power transaction information, and assisting in the identity authentication work of virtual power plant operators.

[0064] The side chain is deployed in the distributed resource layer, which includes interest entities such as small-scale distributed power sources and residential users. As a way for aggregators to coordinate lower-layer distributed resources, the side chain can freely choose the governance structure of a private chain or a consortium chain according to the business model and management form of the aggregator. The smart meters in the distributed resource layer act as light nodes of the side chain, with the function of transaction agents, responding to the price signals of aggregator nodes and recording the information of capital flow.

[0065] In an embodiment of the present invention, as Figure 1 shown, the virtual power plant trading mechanism based on the main-side chain structure includes the following processes:

[0066] Step 1: Pre-trading stage. The virtual power plant node publishes the electricity purchase and sale prices of the power grid as the upper and lower limits of the transaction declaration price; the power grid node publishes the transaction power limit according to the line structure and the node distribution location to avoid power flow congestion. The above information is stored in the main chain temporary block for all nodes to view.

[0067] Step 2: Side chain trading stage. The aggregator nodes in the side chain are divided into two types: fully agent-type aggregators and self-trading-type aggregators.

[0068] 1) The fully agent-type aggregator needs to achieve internal flexible pricing according to the internal load prediction and power generation prediction information. The internal distributed resource entities respond to the price signals of the aggregator through smart meters. The response power information of each entity is temporarily stored in the side chain temporary block. The aggregator integrates the responded power and participates in the main chain transaction.

[0069] 2) The side chain transactions participated by the self-trading-type aggregator conduct continuous two-way auction transactions by publishing power and electricity price information of internal distributed resource entities, call smart contracts to arrange the declaration information in turn according to price, credit value, and power attributes, and complete transaction matching. The transaction power and electricity price information of each entity are stored in the side chain temporary block.

[0070] Step 3, main chain transaction stage. After the transaction is completed in the side chain, there is a surplus or shortage of electricity, so it is necessary to participate in the main chain side transaction. First, each node in the main chain declares the electricity volume and electricity price, and then calls the smart contract to execute the bilateral auction transaction on the main chain. The specific process is the same as the side chain. After the preliminary auction results are formed, they are stored in the temporary block of the main chain. The power grid node performs security verification work, and after obtaining technical confirmation from the power grid node, the final transaction results are formed and stored in the formal block.

[0071] Step 4: Power delivery phase. In this phase, the main and side chain entities execute power supply and consumption according to the transaction results, and the actual power delivery amount is recorded by the smart meter.

[0072] Step 5: Settlement phase. The bill is settled based on the actual electricity delivery information in the smart meter. After the electricity settlement is completed, the actual delivery amount is stored in the formal block, the node reputation value is updated, and the data information in the temporary block is released.

[0073] Compared with other commodities, electric energy is special in that the production, transmission and consumption of electric energy are carried out at the same time. In order to maintain the safe and stable operation of the power system, the power generation in the power system must be balanced with the power consumption at any time. For electric energy transactions, the actual power generation and consumption must be strictly executed according to the transaction results to reduce the pressure on grid regulation. Therefore, in order to ensure the stable and orderly conduct of transactions within the virtual power plant, the embodiment of the present invention proposes a node reputation evaluation model to quantitatively evaluate the reliability of the node.

[0074] The reputation value R(t) reflects the power generation and consumption performance of the node. Taking into account the long-term performance of the node in the market, the reputation evaluation mechanism will be divided into two parts: long-term reputation value RL(t) and short-term reputation value RS(t).

[0075] The short-term reputation value calculation formula is as follows:

[0076]

[0077] Where ΔE(t) represents the deviation between the transaction power and the actual power generation and consumption at time t; ΔE min Indicates the deviation reaches the standard range. When the deviation is less than ΔE min , the node reputation value is 1; ΔE max Indicates the maximum acceptable deviation range. When the deviation is greater than ΔE max , the node reputation value is 0; K is the deviation coefficient, satisfying:

[0078] The long-term reputation value calculation formula is as follows:

[0079]

[0080] The reputation value calculation formula is as follows:

[0081]

[0082] The long-term credit value reflects the performance of the node in two consecutive transactions. If the credit value of this transaction is lower than that of the previous transaction, a part of the credit value will be deducted as a penalty based on the credit value of this transaction; if the credit value of this transaction is higher than that of the previous transaction, a reward will be given based on the credit value of this transaction (the maximum credit value is 1).

[0083] When trading, in order to prevent nodes from maliciously arbitraging using price differences in the market, it is stipulated that only one identity can be selected when participating in the transaction: the electricity purchaser or the electricity seller. At the same time, the node needs to declare the electricity quantity and electricity price information of the pre-transaction within the specified price range. To enable both the electricity purchaser and the electricity seller to make a profit in the transaction, the price range is set as the purchase and sale electricity prices of the power grid, λmax and λmin. The specific bidding strategy can be obtained according to the marginal cost curve formed by its own power generation cost and output.

[0084] After piecewise linearizing the marginal cost curve for the output, the marginal cost curve of the electricity seller is as Figure 4 shown:

[0085]

[0086]

[0087] Among them, C s (P) represents the price when the power generation is P, and k s,i represents the power generation cost of the i-th segment of the curve.

[0088] The marginal cost curve of the electricity purchaser is as Figure 5 shown,

[0089]

[0090]

[0091] Among them, C b (P) represents the price when the electricity consumption is P, and k b,i represents the electricity consumption utility of the i-th segment of the curve.

[0092] The declaration of electricity quantity - electricity price information will be divided into n groups, corresponding to the piecewise linearized marginal cost curve respectively. The electricity quantity declaration ΔPi is the electricity quantity interval corresponding to each segment of the marginal cost; the selling electricity price declaration λs and the purchasing electricity price declaration λb can be adjusted within the specified price range [λmin, λmax] according to the power generation cost and electricity consumption utility. The specific formulas are as follows:

[0093]

[0094] where r b,i and r s,i represent the profit that the node expects to obtain. Taking the electricity seller as an example, if the transaction is finally concluded at the declared electricity price, the profit is:

[0095] I s,i = (λ s,i - k s,i )ΔP i = [(1 + r s,i )k s,i - k s,i ΔP i = r s,i k s,i ΔP i .

[0096] The continuous double - auction mechanism requires both the buyer and the seller to declare the electricity quantity and price of the transaction within the specified time. The transaction arranges the declared information of both the buyer and the seller in the order of electricity price - credit value, and matches according to the lowest price of the electricity seller and the highest price of the electricity buyer. In the first round of auction, since there are cases where the electricity purchase price of some buyers is lower than the electricity selling price of the seller, resulting in transaction failures, multiple rounds of auction bidding need to be organized. After each round of bidding, if there are still buyers and sellers whose transactions have not been completed, the next round of transaction is started. Both the buyer and the seller change their bidding strategies by adjusting the profit margin.

[0097] The strategy for updating the bid can be carried out through the following formula:

[0098] Bid of the electricity seller:

[0099] Bid of the electricity buyer:

[0100] where m represents the highest number of trading rounds, h represents the current trading round, and h ∈ [1, m - 1]. The strategy for updating the bid is to divide the price declared in the first round and the marginal cost into m intervals according to the highest number of trading rounds. When a new transaction fails, the bid is adjusted by giving concessions until it is adjusted to the marginal cost.

[0101] After the buyer and the seller are successfully matched to complete the transaction matching, the price settlement is carried out according to the following formula:

[0102]

[0103] It can be seen from the formula of the settlement price that nodes with a high node credit value will obtain more profits in the transaction. Therefore, it can also encourage nodes to execute the power generation and consumption plans according to the transaction volume.

[0104] If, after the maximum number of trading rounds ends, there are still some electricity purchasers whose purchase prices are lower than the selling prices of the electricity sellers, then the trading will be matched according to the average of the marginal costs of both parties. Finally, when there is only electricity volume to be traded on one side, either the electricity seller or the electricity purchaser, the trading is determined to end.

[0105] After the trading ends and the electricity delivery is completed, the settlement rules are as follows: If the electricity volume sent by the electricity seller is higher than the traded electricity volume, the power grid will purchase it at the basic grid-connected electricity price; if the electricity volume sent by the electricity seller is lower than the traded electricity volume, the electricity seller needs to purchase enough electricity at the grid electricity price, and the cost will be deducted from the final income. Similarly, if the electricity consumption of the electricity purchaser exceeds the traded electricity volume, it will be purchased at the grid electricity price; if the electricity consumption of the electricity purchaser is lower than the traded electricity volume, the settlement will still be based on the traded electricity volume and the electricity price.

[0106] In an embodiment of the present invention, the predicted purchase and sale electricity prices of the external power grid by the current virtual power plant node are 0.3 yuan / kWh and 0.6 yuan / kWh respectively, which are used as the upper and lower limits of the declared electricity prices. The maximum number of trading rounds is set to 3. At this time, there are a total of four parties participating in the trading in the blockchain, namely 2 electricity purchasers and 2 electricity sellers. The declared information is shown in the following table.

[0107] Table 1 Node's First Round Declaration Information

[0108]

[0109] According to the trading rules, the first-round transaction order is obtained:

[0110]

[0111]

[0112] After the first-round trading ends, there is still electricity volume to be traded for Seller 1, Seller 2, and Purchaser 4. However, at this time, the lowest asking price of the electricity seller is the 1-4 strategy of Seller 1 to sell 12 kWh of electricity at 0.52 yuan / kWh, while the highest bid price of the electricity purchaser is the 4-2 strategy of Purchaser 4 to purchase 26 kWh of electricity at 0.51 yuan / kWh. The asking price of the electricity seller is higher than that of the electricity purchaser. Therefore, after adjusting the bidding strategy, the second-round trading is started.

[0113] Table 2 Node's Second Round Declaration Information

[0114]

[0115] According to the trading rules, the second-round transaction order is obtained:

[0116] Transaction sequence Traded user Traded electricity quantity / kWh Traded price / Yuan 1 (1-4,4-2) 12 0.497 2 (2-3,4-2) 14 0.524

[0117] After the second round of transactions, Seller 1 and Seller 2 respectively reached transactions with Buyer 4. At this time, Seller 2's Strategy 2-3 sold 10 kWh of electricity at 0.517 yuan / kWh, and Buyer 4's Strategy 4-3 purchased 20 kWh of electricity at 0.478 yuan / kWh. There was still electricity remaining for transaction between Seller 2 and Buyer 4, but the seller's asking price was higher than the buyer's. The two parties will adjust their asking prices and continue with the third round of transactions.

[0118] Table 3 Node Third Round Declaration Information

[0119]

[0120] According to the trading rules, the third round of transactions is obtained:

[0121] Transaction sequence Traded user Traded electricity quantity / kWh Traded price / Yuan 1 (2-3,4-3) 10 0.481

[0122] Finally, all the electricity of the seller was traded. Buyer 4 still had a demand for 10 kWh of electricity and would purchase it from the power grid at 0.6 yuan / kWh.

[0123] The comparison of the transaction revenues of the power purchase and sale parties and the transaction revenues with the power grid is shown in the following table.

[0124]

[0125]

[0126] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention through logical analysis, reasoning, or limited experiments based on the concept of the present invention on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A virtual power plant trading method based on a main-side chain structure, characterized in that The steps include: Step 1: In the pre-trading stage, the virtual power plant node publishes the power purchase and sale prices of the power grid as the upper and lower limits of the transaction declared power prices. The node publishes the transaction power limit according to the line structure and node distribution location. The upper and lower limits of the declared power price and the transaction power limit are stored in the temporary block of the main chain for the nodes to view; Step 2: In the sidechain transaction phase, the aggregator nodes in the sidechain include fully agent-type aggregators and autonomous transaction-type aggregators; The fully proxy aggregator implements internal pricing based on internal load forecast information and power generation forecast information. The internal distributed resource subject responds to the price signal of the fully proxy aggregator through a smart meter. The response power information of the internal distributed resource subject is temporarily stored in the temporary block of the side chain. The fully proxy aggregator integrates the responded power to participate in the main chain transaction. The side chain transaction in which the autonomous trading aggregator participates conducts continuous two-way auction transactions through the internal distributed resource subject publishing the electricity quantity and the electricity selling price or electricity purchasing price information, calling the smart contract, arranging the declared information in sequence according to the price, reputation value, and electricity quantity attribute, and completing the transaction matching. The transaction quantity and electricity price information of the internal distributed resource subject are stored in the temporary block of the side chain; Step 3, during the main chain transaction phase, when there is a power surplus or power shortage after the transaction is completed in the side chain, the main chain transaction is participated in, including the following steps: Each node in the main chain declares the power consumption and the electricity selling price or electricity purchasing price, and then calls the smart contract to execute the continuous two-way auction transaction on the main chain to form a preliminary auction result; The preliminary auction results are stored in the temporary block of the main chain, and the nodes perform security verification. After obtaining technical confirmation from the nodes, the final transaction results are formed and stored in the official block of the main chain; Step 4: During the power delivery phase, the main chain and side chain entities execute power supply and consumption according to the transaction results, and the smart meter records the actual power delivery amount; Step 5: During the settlement phase, the bill is settled according to the actual electricity delivery information in the smart meter. After the electricity settlement is completed, the actual delivery amount is stored in the main chain formal block, the node reputation value is updated, and the data information in the main chain temporary block is released; Among them, in the step 2, the credit value R(t) includes a long-term credit value R L (t) and a short-term credit value R S (t). The calculation formula of the short-term credit value R S (t) is as follows: Among them, ΔE(t) represents the deviation between the transaction power at time t and the actual power consumption; ΔE min represents the deviation compliance range. When the deviation is less than ΔE min , the node credit value is 1; ΔE max represents the maximum acceptable deviation range. When the deviation is greater than ΔE max , the node credit value is 0; K is the deviation coefficient, satisfying: The long-term reputation value R L (t) is calculated as follows: The reputation value calculation formula is as follows:

2. The virtual power plant trading method based on the main-side chain structure according to claim 1, characterized in that, The long-term reputation value R L (t) reflects the performance of the node in two consecutive transactions. If the reputation value in this transaction is lower than that in the previous transaction, a part of the reputation value will be deducted as a penalty based on the reputation value in this transaction; if the reputation value in this transaction is higher than that in the previous transaction, a reward will be given based on the reputation value in this transaction.

3. The virtual power plant trading method based on the main side-chain structure according to claim 1, characterized in that The selling electricity price λ s，i and the purchasing electricity price λ b,j can be adjusted within the upper and lower bounds of the declared electricity price according to the power generation cost and electricity consumption utility. The specific formula is as follows: where r b,j and r s,i represent the profit that the node wants to obtain, k s,i is the power generation cost, and k b,j is the electricity consumption utility.

4. The virtual power plant trading method based on the main side-chain structure according to claim 3, wherein, When the electricity seller concludes the transaction at the electricity selling price, the profit calculation formula is: I s,i = (λ s,i - k s,i )ΔP i = [(1 + r s,i )k s,i - k s,i )ΔP i = r s,i k s,i ΔP i Among them, ΔP i is the transaction electricity volume.

5. The virtual power plant trading method based on the main side-chain structure according to claim 3, wherein The continuous double auction transaction comprises the following steps: S1. The electricity seller and the electricity buyer declare the transaction volume and the electricity sales price or electricity purchase price within the specified time; S2. Arrange the declared information of the electricity seller and the electricity buyer in the order of electricity price-credit value; S3. Match the lowest price of the electricity seller with the highest price of the electricity buyer; S4. If the purchase price of electricity by the electricity buyer is not lower than the electricity selling price of the electricity seller, the transaction is successful. If the purchase price of electricity by the electricity buyer is lower than the electricity selling price of the electricity seller, the transaction fails and this round of transaction ends. S5. If only the electricity seller or the electricity buyer has electricity to be traded, or the transaction rounds exceed the preset maximum transaction rounds, the transaction is determined to be completed; otherwise, the electricity buyer and the electricity seller re-price by adjusting the profit margin to update the quotation strategy and execute step S1.

6. The virtual power plant trading method based on the main side-chain structure according to claim 5, characterized in that In the step S5, the strategy for updating the quotation is carried out by the following formula: Selling electricity price: Purchase electricity price: Where m represents the highest trading round, h represents the current trading round, and h ∈ [1, m - 1].

7. The virtual power plant trading method based on the main side-chain structure according to claim 6, characterized in that, The strategy for updating the quotation is to divide the price declared in the first round and the marginal cost into m intervals according to the highest trading round, where m is a positive integer greater than 0. When a new transaction fails, the quotation is adjusted with a concession until it is adjusted to the marginal cost.

8. The virtual power plant trading method based on the main side-chain structure according to claim 7, characterized in that, After the seller and the buyer of electricity are successfully matched to complete the transaction matching, the price settlement is carried out according to the following formula:

9. The virtual power plant trading method based on the main side-chain structure according to claim 8, wherein If, after the end of the maximum trading round, there is still a situation where the electricity purchase price of some electricity buyers is lower than the electricity selling price of the electricity seller, then the transaction matching is carried out according to the average value of the marginal costs of both parties.

Images