A method and system for controlling active power of a power grid taking into account both responsiveness and economy

Abstract

The present invention discloses a method and system for regulating active power of a power grid that takes into account both response enthusiasm and economy, and belongs to the field of power system control. The method and system include: setting a step-by-step regulation cost coefficient based on the regulation cost coefficient of each park-level distribution network in response to the power distribution / peak-shaving instruction of the upper-level power grid; based on the step-by-step regulation cost coefficient, the aggregated adjustable margin of each distribution network is evaluated in real time by a management platform, with the goal of improving the enthusiasm of distribution network users to participate in the response and taking into account economy, obtaining the optimal instruction allocation plan between each distribution network and completing the issuance. The present invention can comprehensively consider the regulation cost and response enthusiasm of each park-level distribution network when participating in the power distribution / peak-shaving of the upper-level power grid, while reducing the overall regulation cost and preventing the instruction capacity borne by each distribution network from being too different, solving the problem that the long-term response enthusiasm of distribution network users with poor economy is reduced due to the excessively high response priority of some distribution networks with better economy.

Description

Technical Field

[0001] The present invention relates to the field of power system control, and in particular to a method and system for regulating active power of a power grid that takes into account both responsiveness and economy. Background Art

[0002] The rapid increase in renewable energy penetration is causing increasing randomness and volatility in grid operation, leading to a lack of flexibility in the new power system during certain periods. Furthermore, the cost of retrofitting traditional generators to provide flexibility is high, and the replacement of some thermal power units with renewable energy sources has reduced the amount of flexible power, further increasing the system's flexibility deficit. The power supply's regulation capacity is no longer sufficient to ensure the traditional reliable and economic operation of the new power system. There is an urgent need to aggregate load-side flexibility resources to participate in grid dispatch and control, providing peak-shaving and frequency-regulating capacity to support the safe and stable operation of the power system.

[0003] At present, some scholars are conducting research on aggregating load-side flexibility resources to participate in grid dispatching and control, controlling flexibility resources to participate in peak shaving, and reducing redundant investment in grids and power sources. Among them, some scholars have proposed aggregating a single type of load, but this does not adapt to the hierarchical control structure of the power system, reduces the active and reactive power control effect of the distribution network, and fails to give full play to the regulation potential of all flexibility resources in the distribution network. It can be considered to aggregate multiple park-level distribution network loads within a certain range to participate in grid regulation. However, in the hierarchical control approach of aggregating multiple distribution network flexibility resources to participate in grid regulation, existing studies mostly design control modes from the perspectives of economic dispatch, market competition, low-carbon and environmental protection, ignoring the problem that under the above-mentioned single-objective control mode, some users with poor economic efficiency or low environmental benefits have too low a priority to participate in the response, making it difficult to maintain their enthusiasm for long-term participation in the response; some studies have also proposed equal margin and equal capacity allocation methods, which, although ensuring the enthusiasm of users to participate in the response, greatly increase the regulation cost. Therefore, there is an urgent need to propose a distribution technology for grid active control instructions among distribution networks that takes into account both response enthusiasm and economy and is compatible with the hierarchical control structure of the power system, to ensure that each distribution network user can provide effective support to the power grid in a long-term, stable and economical manner. Summary of the Invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a technology for allocating active power control instructions of the power grid among distribution networks, which takes into account both response enthusiasm and economy. It aims to solve the problem that in a control mode that ignores response enthusiasm, the response priority of some distribution network users is too low, making it difficult to maintain the enthusiasm for long-term participation in the response.

[0005] In order to achieve the above technical objectives, the present application provides a method for controlling active power of a power grid that takes into account both responsiveness and economy, comprising the following steps:

[0006] According to the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid, a step-by-step control cost coefficient is set;

[0007] Based on the step-by-step control cost coefficient, the aggregate adjustable margin of each distribution network is evaluated in real time through the management platform, with the goal of increasing the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, and obtaining the optimal instruction allocation plan between the distribution networks and completing the issuance.

[0008] Preferably, in the process of improving the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, the objective function of the optimization model that takes into account both the enthusiasm for response and economic efficiency is expressed as:

[0009]

[0010] Where, γ i is the correction coefficient to consider the response enthusiasm of distribution network users, N is the number of park-level distribution networks, P adj is the capacity that needs to be adjusted by the management platform, ρ 0，i is the basic electricity price coefficient, ΔP i is the active power value of the i-th park-level distribution network participating in the response.

[0011] Preferably, in the process of obtaining the step-by-step control cost coefficient, the step-by-step control cost coefficient is expressed as:

[0012]

[0013] Preferably, in the process of obtaining the optimization model, constraints of the optimization model are set, including power balance constraints, adjustable range constraints of campus-level distribution network PCC nodes, and reverse power flow constraints of feeder capacity.

[0014] Preferably, in the process of obtaining the power balance constraint, the power balance constraint is expressed as:

[0015]

[0016] Preferably, in the process of obtaining the adjustable range constraint of the campus-level distribution network PCC node, the adjustable range constraint is expressed as:

[0017] P af，i ≤P PCC，i -ΔP i ≤P au，i

[0018] Where, P PCC，i is the PCC node power prediction curve of the i-th campus-level distribution network; P au,i 、P af，i They are the adjustable upper and lower limits of the PCC node in the i-th campus-level distribution network.

[0019] Preferably, in the process of obtaining the reverse power flow constraint of the feeder capacity, the reverse power flow constraint is expressed as:

[0020] P lim，i ≤P PCC，i -ΔP i

[0021] Where, P limi is the reverse transmission capacity limit of the i-th campus-level distribution network feeder.

[0022] Preferably, in the process of considering the response enthusiasm of the distribution network users, the correction coefficient of the response enthusiasm of the distribution network users is expressed as:

[0023]

[0024] Where, P a，i is the adjustable margin of the PCC node in the i-th campus-level distribution network; P au,i 、P af，i are the adjustable upper and lower limits of the PCC node of the i-th campus-level distribution network; It is the sum of the adjustable margins of each distribution network PCC node.

[0025] The present invention discloses a power grid active power control system that takes into account both responsiveness and economy, comprising:

[0026] The coefficient adjustment module is used to set a stepped control cost coefficient based on the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid;

[0027] The control module is used to evaluate the aggregate adjustable margin of each distribution network in real time based on the step-by-step control cost coefficient through the management platform, with the goal of improving the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, to obtain the optimal instruction allocation plan among the distribution networks and complete the issuance.

[0028] Preferably, the control module is further used to obtain an objective function of an optimization model that takes into account both responsiveness and economy, which is expressed as:

[0029]

[0030] Where, γ i is the correction coefficient to consider the response enthusiasm of distribution network users, N is the number of park-level distribution networks, P adj is the capacity that needs to be adjusted by the management platform, ρ 0，i is the basic electricity price coefficient, ΔP i is the active power value of the i-th park-level distribution network participating in the response.

[0031] The present invention discloses the following technical effects:

[0032] The present invention considers the impact of the differences in capacity allocation between distribution networks on the enthusiasm of distribution network users to participate in the response. By adding a correction coefficient, on the basis of the original objective function of the lowest overall response cost, it adds consideration of response enthusiasm, ensuring that distribution network users with higher adjustable margins will bear higher control instruction capacity; at the same time, the traditional fixed control cost coefficient is expanded to a step-by-step cost coefficient, avoiding the problem of individual distribution network users with better economic efficiency and higher adjustable margins bearing too high a control instruction capacity. Compared with existing methods, the present invention can achieve the optimal allocation of power grid control instructions between distribution networks, adapt to the control framework of the new type of power system hierarchical control, and has high practical value. Compared with existing methods, the present invention can comprehensively consider the control cost and response enthusiasm of each park-level distribution network when participating in the power distribution / peak regulation of the upper power grid, while reducing the overall control cost, solving the problem of low enthusiasm of some distribution network users with poor economic efficiency to participate in the response. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 It is the control framework for aggregating multiple park-level distribution networks to participate in power grid regulation as described in the present invention;

[0035] Figure 2 This is a flow chart of the centralized control platform of the present invention for allocating control instructions between distribution networks. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0037] like Figure 1-2 As shown, the present invention provides a method for controlling active power of a power grid taking into account both responsiveness and economy, comprising the following steps:

[0038] According to the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid, a step-by-step control cost coefficient is set;

[0039] Based on the step-by-step control cost coefficient, the aggregate adjustable margin of each distribution network is evaluated in real time through the management platform, with the goal of increasing the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, and obtaining the optimal instruction allocation plan between the distribution networks and completing the issuance.

[0040] Further preferably, in the grid active power control method provided by the present invention, in the process of improving the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, the objective function of the optimization model that takes into account both the response enthusiasm and economic efficiency is expressed as:

[0041]

[0042] Where, γ i is the correction coefficient to consider the response enthusiasm of distribution network users, N is the number of park-level distribution networks, P adj is the capacity that needs to be adjusted by the management platform, ρ 0，i is the basic electricity price coefficient, ΔP i is the active power value of the i-th park-level distribution network participating in the response.

[0043] Further preferably, in the grid active power control method provided by the present invention, in the process of obtaining the step-by-step control cost coefficient, the step-by-step control cost coefficient is expressed as:

[0044]

[0045] Further preferably, the grid active power control method provided by the present invention sets the constraints of the optimization model in the process of obtaining the optimization model, including power balance constraints, adjustable range constraints of the campus-level distribution network PCC nodes, and reverse flow constraints of the feeder capacity.

[0046] Preferably, in the process of obtaining the power balance constraint, the power balance constraint is expressed as:

[0047]

[0048] Further preferably, in the method for controlling active power of a power grid provided by the present invention, in the process of obtaining the adjustable range constraint of the PCC node of the campus-level distribution network, the adjustable range constraint is expressed as:

[0049] P af，i ≤P PCC，i -ΔP i ≤P au，i

[0050] Where, PPCC，i is the PCC node power prediction curve of the i-th campus-level distribution network; P au,i 、P af，i They are the adjustable upper and lower limits of the PCC node in the i-th campus-level distribution network.

[0051] Further preferably, in the grid active power control method provided by the present invention, in the process of obtaining the reverse power flow constraint of the feeder capacity, the reverse power flow constraint is expressed as:

[0052] P lim，i ≤P PCC，i -ΔP i

[0053] Where, P lim，i is the reverse transmission capacity limit of the i-th campus-level distribution network feeder.

[0054] Further preferably, in the method for controlling active power of the power grid provided by the present invention, in the process of considering the response enthusiasm of the distribution network users, the correction coefficient of the response enthusiasm of the distribution network users is expressed as:

[0055]

[0056] Where, P a，i is the adjustable margin of the PCC node in the i-th campus-level distribution network; P au,i 、P af，i are the adjustable upper and lower limits of the PCC node of the i-th campus-level distribution network; It is the sum of the adjustable margins of each distribution network PCC node.

[0057] The present invention discloses a grid active power control system that takes into account both responsiveness and economy, to implement the above-mentioned grid active power control method, including:

[0058] The coefficient adjustment module is used to set a stepped control cost coefficient based on the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid;

[0059] The control module is used to evaluate the aggregate adjustable margin of each distribution network in real time based on the step-by-step control cost coefficient through the management platform, with the goal of improving the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, to obtain the optimal instruction allocation plan among the distribution networks and complete the issuance.

[0060] Further preferably, the control module of the system disclosed in the present invention is also used to obtain the objective function of the optimization model that takes into account both response positivity and economy, and is expressed as:

[0061]

[0062] Where, γ iis the correction coefficient to consider the response enthusiasm of distribution network users, N is the number of park-level distribution networks, P adj is the capacity that needs to be adjusted by the management platform, ρ 0，i is the basic electricity price coefficient, ΔP i is the active power value of the i-th park-level distribution network participating in the response.

[0063] Embodiment: The present invention discloses a method for allocating active power control instructions among distribution networks that takes into account both responsiveness and economy. Specifically, the method includes the following processes: a centralized management platform determines the control cost coefficient of each park-level distribution network in responding to the power distribution / peak-shaving instructions of the upper-level power grid on the previous day, and evaluates the aggregate adjustable margin of each distribution network within the day; when receiving the power distribution / peak-shaving instructions from the upper-level power grid, the centralized management platform optimizes and solves the optimal instruction allocation scheme among the distribution networks based on an optimization model that takes into account both responsiveness and economy, and completes the issuance. This method for allocating active power control instructions can comprehensively consider the control cost and responsiveness of each park-level distribution network when participating in the power distribution / peak-shaving of the upper-level power grid, while reducing the overall control cost and preventing the instruction capacity borne by each distribution network from being too different. This solves the problem that the long-term response enthusiasm of users of distribution networks with poor economy is reduced due to the excessively high response priority of some distribution networks with better economy.

[0064] The present invention takes the centralized control platform to aggregate multiple distribution networks to respond to the grid peak load instruction as an example to illustrate the control framework of multiple park-level distribution networks participating in grid regulation. Figure 1 shown.

[0065] The distribution network control platform coordinates the control of internal flexibility resources, monitors the operating status of each internal adjustable unit, and uploads the aggregate adjustable margin of the distribution network to the centralized control platform; based on the contracts signed with each distribution network user and the current aggregate adjustable margin of each distribution network, when the centralized control platform receives the peak-shaving instruction from the power grid during the day, it solves and issues the peak-shaving instruction allocation plan between distribution networks that takes into account both response enthusiasm and economy.

[0066] The flowchart of the centralized control platform for command distribution between distribution networks is as follows: Figure 2 The specific steps are as follows:

[0067] Step 1: Determine the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid before the current day;

[0068] Step 2: The centralized management platform evaluates the aggregate adjustable margin of each distribution network in real time;

[0069] Step 3: When receiving the power allocation / peak-shaving instructions from the upper-level power grid, the centralized management platform obtains the optimal instruction allocation plan between the distribution networks based on the aggregated adjustable margin of the current distribution networks, and completes the issuance by optimizing the optimization model that takes into account both response positivity and economy.

[0070] A common objective function of conventional distribution network command allocation methods is to minimize the control cost, as shown in the following formula:

[0071]

[0072] Where: ΔP i is the active power value of the i-th park-level distribution network participating in the response, and a positive value is defined as a decrease in the distribution network's purchase of electricity from upstream or an increase in the distribution network's sale of electricity to upstream; N is the number of park-level distribution networks aggregated and regulated by the management platform; ρ i The cost coefficient of peak load regulation for each park-level distribution network is ρ i (Yuan / MW), to be determined when the contract is signed a few days ago.

[0073] The present invention provides a method for distributing active power control instructions of a power grid among distribution networks, which takes into account both response enthusiasm and economy. On the basis of the above-mentioned objective function, the traditional fixed control cost coefficient is expanded into a step-by-step cost coefficient, and a correction coefficient is added to consider the response enthusiasm of distribution network users. A single objective function is constructed that comprehensively considers the control cost and response enthusiasm of each park-level distribution network when participating in the power distribution / peak regulation of the upper-level power grid. This prevents excessive differences in the instruction capacity borne by each distribution network while reducing the overall control cost, ensures the enthusiasm for distributing peak-shaving instructions among distribution networks, and improves the enthusiasm of distribution network users to participate in the response.

[0074] The objective function of the optimization model that takes into account both response positivity and economy is:

[0075]

[0076] Where: γ i It is a correction factor considering the response enthusiasm of distribution network users.

[0077] The step-by-step control cost coefficients are as follows:

[0078]

[0079] Where: P adj The capacity that the management platform needs to adjust to reduce the purchase of electricity from the grid or increase the sale of electricity to the grid is positive; ΔP i is the active power value of the i-th park-level distribution network participating in the response, and a positive value is defined as a decrease in the distribution network's purchase of electricity from upstream or an increase in the distribution network's sale of electricity to upstream; N is the number of park-level distribution networks aggregated and regulated by the management platform; ρ i (Yuan / MW) is the cost coefficient for the peak load regulation of the distribution network at each park level, which is determined when the contract is signed on the previous day; ρ 0,i It is the basic electricity price coefficient and is determined when the contract is signed a few days ago.

[0080] The constraints of the optimization model that takes into account both responsiveness and economy specifically include:

[0081] Power balance constraints:

[0082]

[0083] Constraints on the adjustable range of PCC nodes in the campus distribution network:

[0084] P af,i ≤P PCC,i -ΔP i ≤P au,i ;

[0085] Where: P PCC,i is the PCC node power prediction curve of the i-th campus-level distribution network; P au,i 、P af,i They are the adjustable upper and lower limits of the PCC node in the i-th campus-level distribution network.

[0086] Reverse power flow constraints of feeder capacity:

[0087] P lim,i ≤P PCC,i -ΔP i ;

[0088] Where: P lim,i is the reverse transmission capacity limit of the i-th campus-level distribution network feeder.

[0089] The correction coefficient considering the response enthusiasm of distribution network users is:

[0090]

[0091] Where: P a,i is the adjustable margin of the PCC node in the i-th campus-level distribution network; P au,i 、P af,i are the adjustable upper and lower limits of the PCC node of the i-th campus-level distribution network; It is the sum of the adjustable margins of each distribution network PCC node.

[0092] By solving an optimization model that takes into account both response enthusiasm and economy, it is possible to reduce the overall regulation cost while ensuring the enthusiasm of peak-shaving instruction allocation among distribution networks and improving the enthusiasm of distribution network users to participate in the response.

[0093] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0094] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0095] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for controlling active power of a power grid that takes into account both responsiveness and economy, characterized in that: The following steps are involved: According to the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid, a step-by-step control cost coefficient is set; Based on a step-by-step control cost coefficient, the management platform evaluates the aggregate adjustable margin of each distribution network in real time. With the goal of increasing the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency, the optimal command allocation plan between distribution networks is obtained and issued. In the process of improving the enthusiasm of distribution network users to participate in the response and taking into account the economic efficiency, the objective function of the optimization model that takes into account both the enthusiasm and the economic efficiency is expressed as: Where, γ i is the correction coefficient to consider the response enthusiasm of distribution network users, N is the number of park-level distribution networks, P adj is the capacity that needs to be adjusted by the management platform, ρ 0，i is the basic electricity price coefficient, ΔP i is the active power value of the i-th park-level distribution network participating in the response.

2. A method for controlling active power of a power grid that takes into account both responsiveness and economy according to claim 1, characterized in that: In the process of obtaining the step-by-step control cost coefficient, the step-by-step control cost coefficient is expressed as:

3. The method for controlling active power of a power grid that takes into account both responsiveness and economy according to claim 1, characterized in that: In the process of considering the response enthusiasm of distribution network users, the correction coefficient of the response enthusiasm of distribution network users is expressed as: Where, P a,i is the adjustable margin of the PCC node in the i-th campus-level distribution network; P au,i 、P af,i are the adjustable upper and lower limits of the PCC node of the i-th campus-level distribution network; is the sum of the adjustable margins of each distribution network PCC node, P PCC,i is the PCC node power prediction curve of the i-th campus-level distribution network.

4. The method for controlling active power of a power grid that takes into account both responsiveness and economy according to claim 2, characterized in that: In the process of obtaining the optimization model, constraints of the optimization model are set, including power balance constraints, adjustable range constraints of campus-level distribution network PCC nodes, and reverse power flow constraints of feeder capacity.

5. The method for controlling active power of a power grid according to claim 4, wherein: In the process of obtaining the power balance constraint, the power balance constraint is expressed as:

6. A method for controlling active power of a power grid that takes into account both responsiveness and economy according to claim 5, characterized in that: When obtaining the adjustable range constraint of the PCC node in the campus-level distribution network, the adjustable range constraint is expressed as: P af，i ≤P PCC，i -ΔP i ≤P au,i Where, P PCC,i is the PCC node power prediction curve of the i-th campus-level distribution network; P au,i 、P af,i They are the adjustable upper and lower limits of the PCC node in the i-th campus-level distribution network.

7. A method for controlling active power of a power grid that takes into account both responsiveness and economy according to claim 6, characterized in that: In the process of obtaining the reverse power flow constraint of the feeder capacity, the reverse power flow constraint is expressed as: P lim,i ≤P PCC，i -ΔP i Where, P lim,i is the reverse transmission capacity limit of the i-th campus-level distribution network feeder.

8. A power grid active power control system that takes into account both responsiveness and economy, characterized in that: include: The coefficient adjustment module is used to set a stepped control cost coefficient based on the control cost coefficient of each park-level distribution network in response to the power allocation / peak regulation instruction of the upper power grid; The control module is used to obtain and issue the optimal instruction allocation plan among distribution networks based on the step-by-step control cost coefficient and the aggregate adjustable margin of each distribution network evaluated in real time by the management platform, with the goal of increasing the enthusiasm of distribution network users to participate in the response while taking into account economic efficiency. The control module is also used to obtain the objective function of the optimization model that takes into account both response positivity and economy, which is expressed as: Where, γ i is the correction coefficient to consider the response enthusiasm of distribution network users, N is the number of park-level distribution networks, P adj is the capacity that needs to be adjusted by the management platform, ρ 0，i is the basic electricity price coefficient, ΔP i is the active power value of the i-th park-level distribution network participating in the response.

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