Voltage out-of-limit treatment method and system based on user active and passive responsibility division

Abstract

The invention provides a voltage out-of-limit treatment method and system based on user active and passive responsibility division. The method comprises the following steps: periodically acquiring electrical data which does not contain distributed photovoltaic nodes and can adjust the distributed photovoltaic nodes through a transformer area data acquisition device; the transformer area terminal judges whether the real-time node voltage is out of limit or not, and when an out-of-limit node exists, user active responsibility and user passive responsibility are calculated; establishing a target function with the minimum line loss and the minimum distributed photovoltaic active reduction quantity as targets, and solving to obtain the regulating variables of the distributed photovoltaic active power and the distributed photovoltaic reactive power; the transformer area terminal downloads active and reactive regulation quantity instructions to each adjustable distributed photovoltaic node; each adjustable distributed photovoltaic node carries out active and reactive power adjustment; according to the method, the active and passive responsibilities of distributed photovoltaic can be fully considered, the active and passive responsibilities of voltage out-of-limit caused by distributed photovoltaic can be accurately and scientifically divided, and the accuracy and rationality of transformer area voltage management can be improved.

Description

Technical Field

[0001] The present invention relates to a voltage over-limit management method and system based on user active and passive responsibility division, belonging to the technical field of voltage management. Background Art

[0002] With the rapid development of new energy technologies, widespread integration of distributed photovoltaic systems into rural power grids is becoming a growing trend. The integration of distributed photovoltaic systems into rural power grids will alter the existing radial power distribution. Furthermore, photovoltaic output is significantly affected by environmental factors such as sunlight intensity, resulting in fluctuations and intermittentity. The voltage at the point of connection of distributed photovoltaic systems will rise with the added photovoltaic power, significantly improving undervoltage conditions that can occur at the end of rural power grid lines. However, due to the generally low load factor in rural power distribution areas, when the distributed photovoltaic power grid-connected power is excessive, if the active power output of the distributed photovoltaic systems cannot be promptly absorbed locally, power backflow will occur on the distribution network lines, leading to voltage increases and voltage over-limit issues, seriously impacting the power quality and safe and stable operation of the distribution network. Therefore, it is urgent to address the voltage over-limit issues caused by the integration of distributed photovoltaic systems.

[0003] Currently, the mainstream method to solve the problem of over-limit voltage in substations is cluster division and management, which comprehensively considers the amount of abandoned light, line loss and power distribution to manage substation voltage problems. However, this method ignores the active and passive responsibilities of distributed photovoltaic owners, and the division method is too general, resulting in low accuracy and rationality of substation voltage management, making it difficult to apply and promote on a large scale. Summary of the Invention

[0004] The purpose of the present invention is to provide a voltage over-limit management method and system based on the division of active and passive responsibilities of users to solve the problem in the prior art that the accuracy and rationality of substation voltage management need to be improved.

[0005] The technical solution of the present invention is: A voltage over-limit control method based on user active and passive responsibility division includes the following steps: S1. Periodically obtain electrical data including real-time node voltages of distributed photovoltaic nodes and adjustable distributed photovoltaic nodes through the substation data acquisition device. , active and reactive loads and distributed photovoltaic power generation, where i is the branch number and j is the node number, and the electrical data is sent to the substation terminal; S2, the substation terminal determines the real-time node voltage based on the received electrical data Whether it is out of limit, if there is an out of limit node, go to the next step S3; otherwise return to step S1; S3. Calculating User Active Responsibility Passive liability of users ; S4, user active responsibility obtained from step S3 Passive liability of users , establish the objective function with the goal of minimizing line loss and minimizing distributed photovoltaic active power reduction, and solve to obtain the regulation amount of distributed photovoltaic active and reactive power; S5. The substation terminal transmits the active and reactive power regulation instructions to each adjustable distributed photovoltaic node; S6. Each adjustable distributed photovoltaic node performs active and reactive power regulation according to active and reactive regulation quantity instructions.

[0006] Furthermore, in step S2, the substation terminal determines the real-time node voltage from the received electrical data. Whether it exceeds the limit, specifically, the real-time node voltage Greater than the voltage safe operation threshold U max If , there is an out-of-limit node; otherwise, there is no out-of-limit node.

[0007] Furthermore, in step S3, the user's active responsibility is calculated When the net load is larger, the user's active responsibility is greater; when calculating the user's passive responsibility When the user is closer to the end of the area, the passive responsibility is greater.

[0008] Furthermore, in step S3, the user's active responsibility is calculated Passive liability of users , specifically, S21. User active responsibility of node (i, j) Related to the net power generation of the node (i, j), calculate the user's active responsibility : , in, is the active power output by the photovoltaic inverter connected to node (i, j), is the active power consumed by the load at node (i, j); S21. User passive responsibility of node (i, j) Related to the location of the node (i, j), calculate the user's passive responsibility : , in, , are the minimum node and maximum node of branch i respectively.

[0009] Furthermore, in step S4, an objective function is established with the goal of minimizing line loss and minimizing distributed photovoltaic active power reduction. : , wherein, , respectively represent constraint functions, is the output active power of the distributed photovoltaic of node (i,j), is the active load of node (i,j), is the current flowing through node (i,j), is the resistance value of the line between node (i,j) and the previous node; the constraint conditions are: , wherein, is the real-time node voltage of node (i,j), is the terminal voltage of the distribution area, , is the equivalent consumption power of node (i,j), , is the line parameter, , is the lower limit and the upper limit of the safe operation range of the node voltage of the distribution area, is the active power output by the photovoltaic inverter accessed by node (i,j), is the reactive power output by the photovoltaic inverter accessed by node (i,j), is the rated capacity of the photovoltaic inverter accessed by node (i,j).

[0010] A voltage out-of-limit management system based on user active and passive responsibility division adopting the method described in any one of the above, comprising a distribution area data acquisition device, a distribution area terminal, a node without distributed photovoltaic, and an adjustable distributed photovoltaic node, the distribution area data acquisition device: periodically acquires electrical data of the node without distributed photovoltaic and the adjustable distributed photovoltaic node, including real-time node voltage , active and reactive load, and distributed photovoltaic power generation, wherein i is branch number and j is node number, and sends the electrical data to the distribution area terminal; the distribution area terminal: determines whether the real-time node voltage is out of limit by the received electrical data, when there is an out-of-limit node, calculates user active responsibility and user passive responsibility , establishes a target function with the minimum line loss and the minimum distributed photovoltaic active power reduction as the target, and solves to obtain the adjustment amount of the distributed photovoltaic active and reactive power; the active and reactive adjustment amount instructions are transmitted to each adjustable distributed photovoltaic node; otherwise, the distribution area data acquisition device continuously acquires the electrical data of each node; Adjustable distributed photovoltaic nodes: Active and reactive power are adjusted according to active and reactive power regulation instructions.

[0011] The beneficial effects of the present invention are: this voltage over-limit management method and system based on the division of active and passive responsibilities of users can fully consider the active and passive responsibilities of distributed photovoltaics when dividing the responsibilities for voltage over-limit management, can accurately and scientifically divide the active and passive responsibilities of distributed photovoltaics causing voltage over-limit, can improve the accuracy and rationality of substation voltage management, can achieve an effective balance between minimizing substation line losses and minimizing the reduction in power generation income of distributed photovoltaic owners, and can ensure the power quality and power supply safety of rural power grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a flow chart of a voltage over-limit control method based on user active and passive responsibility division according to an embodiment of the present invention; Figure 2 This is a topological diagram of the substation area in the embodiment; Figure 3 This is a schematic diagram illustrating a voltage over-limit management system based on the division of active and passive responsibilities of users in an embodiment. DETAILED DESCRIPTION

[0013] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0014] The embodiment provides a voltage over-limit management method based on the division of active and passive responsibilities of users, such as Figure 1 , including the following steps,

[0015] S1. Periodically obtain electrical data including real-time node voltages of distributed photovoltaic nodes and adjustable distributed photovoltaic nodes through the substation data acquisition device. , active and reactive loads and distributed photovoltaic power generation, where i is the branch number and j is the node number, and the electrical data is sent to the substation terminal.

[0016] In step S1, Figure 2 As shown in the figure, a certain area topology diagram, where the black nodes represent nodes without distributed photovoltaic nodes, and the red nodes represent nodes with adjustable distributed photovoltaic inverters. Collect electrical data and upload it to the substation terminal.

[0017] S2, the substation terminal determines the real-time node voltage based on the received electrical data Whether it exceeds the limit, if there is an exceeding limit node, go to the next step S3; otherwise return to step S1.

[0018] In step S2, the voltage of each node is received from the data acquisition device in the substation area. If the voltage of each node is within the safe operation threshold, that is, ,in, , Respectively represent the minimum and maximum number of branches, Indicates the minimum and maximum number of nodes, Respectively represent the minimum voltage and maximum voltage for safe operation of the substation voltage, then no instructions will be sent down, and the substation data acquisition device will continue to monitor the electrical data of each node; if there is a node voltage in the substation that is outside the safe voltage threshold, that is, , then there is an out-of-limit node.

[0019] S3. Calculating User Active Responsibility Passive liability of users .

[0020] S31. User active responsibility of node (i, j) Related to the net power generation of the node (i, j), calculate the user's active responsibility : , in, is the active power output by the photovoltaic inverter connected to node (i, j), is the active power consumed by the load at node (i, j); S31. User passive responsibility of node (i, j) Related to the location of the node (i, j), calculate the user's passive responsibility : , in, , are the minimum node and maximum node of branch i respectively.

[0021] S4, user active responsibility obtained from step S3 Passive liability of users , establish an objective function with the goal of minimizing line loss and minimizing distributed photovoltaic active power reduction, and solve to obtain the regulation amount of distributed photovoltaic active and reactive power.

[0022] In step S4, an objective function is established with the goal of minimizing line loss and minimizing distributed photovoltaic active power reduction. : , in, , They represent the constraint functions, is the output active power of distributed photovoltaic at node (i, j), is the active load of node (i, j), is the current flowing through the node (i, j), is the resistance value of the line between node (i, j) and the previous node; The constraints are: , in, is the real-time node voltage of node (i, j), is the voltage at the head end of the station, 、 is the equivalent power consumption of node (i, j), 、 is the line parameter, , The lower and upper limits of the safe operating range of the node voltage in the distribution station area are: is the active power output by the photovoltaic inverter connected to node (i, j), is the reactive power output by the photovoltaic inverter connected to node (i, j), is the rated capacity of the photovoltaic inverter connected to node (i, j). In a specific example, , , Indicates the voltage level of the substation.

[0023] S5. The substation terminal transmits the active and reactive power regulation instructions to each adjustable distributed photovoltaic node.

[0024] S6. Each adjustable distributed photovoltaic node performs active and reactive power regulation according to active and reactive regulation quantity instructions.

[0025] In step S6, the adjustable distributed photovoltaic node performs power adjustment after receiving the power adjustment instruction issued by the substation terminal, and continues to cycle the entire voltage control process after the adjustment.

[0026] This voltage over-limit management method based on the division of active and passive responsibilities of users can fully consider the active and passive responsibilities of distributed photovoltaics when dividing the responsibilities for voltage over-limit management, can accurately and scientifically divide the active and passive responsibilities of distributed photovoltaics causing voltage over-limit, can improve the accuracy and rationality of substation voltage management, can achieve an effective balance between minimizing substation line losses and minimizing the reduction in power generation income of distributed photovoltaic owners, and can ensure the power quality and power supply safety of rural power grids.

[0027] The embodiment also provides a voltage over-limit management system based on user active and passive responsibility division using any of the above methods, such as Figure 3, including substation data acquisition devices, substation terminals, general nodes excluding distributed photovoltaic nodes and adjustable distributed photovoltaic nodes.

[0028] Substation data acquisition device: periodically obtains electrical data excluding distributed photovoltaic nodes and adjustable distributed photovoltaic nodes, including real-time node voltage , active and reactive loads and distributed photovoltaic power generation, where i is the branch number and j is the node number, and the electrical data is sent to the substation terminal;

[0029] Substation terminal: Determine the real-time node voltage based on the received electrical data Whether it exceeds the limit, when there is an exceeding limit node, calculate the user's active responsibility Passive liability of users , establish an objective function with the goal of minimizing line loss and distributed photovoltaic active power reduction, and solve to obtain the adjustment amount of distributed photovoltaic active and reactive power; transmit the active and reactive adjustment amount instructions to each adjustable distributed photovoltaic node; otherwise, the substation data acquisition device continuously collects electrical data from each node;

[0030] Adjustable distributed photovoltaic nodes: Active and reactive power are adjusted according to active and reactive power regulation instructions.

[0031] This voltage over-limit management method and system based on the division of active and passive responsibilities of users fully considers the active and passive responsibilities of distributed photovoltaics when dividing the responsibility for voltage over-limit management, and can achieve accurate division of management responsibilities. In terms of passive responsibility, if the access location of distributed photovoltaics is closer to the end of the substation, the impact of photovoltaic access on the substation voltage will usually be greater. However, its access location is objectively affected by the substation access point, and it is difficult for the distributed photovoltaic owners themselves to adjust. At this time, the passive responsibility of the distributed photovoltaic access location should be reasonably considered in the voltage over-limit management task. The closer the user is to the end of the substation, the greater the passive responsibility. When the distributed photovoltaic grid-connected capacity is too large and the local load is small, resulting in an excessive net load and the substation voltage is over-limited, the active responsibility of the distributed photovoltaics should be fully considered. The greater the net load, the greater the active responsibility of the user.

[0032] This voltage over-limit control method and system based on the division of user active and passive responsibilities periodically obtains the electrical data of each node including real-time voltage, active and reactive loads and distributed photovoltaic power generation through the substation data acquisition device; the substation terminal determines whether the node voltage is over-limit based on the electrical data, and calculates the user's active responsibility when there is an over-limit node. Passive liability of users ; Based on user's active responsibility Passive liability of users , calculating the regulation amount of distributed photovoltaic active and reactive power; the substation terminal transmits the active and reactive regulation amount instructions to the adjustable distributed photovoltaic at each node; the distributed photovoltaic at each node automatically adjusts the active and reactive power according to the regulation amount instructions. This invention scientifically divides the active and passive responsibilities for voltage over-limit caused by distributed photovoltaics, and balances the goals of minimizing substation line losses and minimizing the reduction in power generation revenue for distributed photovoltaic owners. This can effectively improve the accuracy and rationality of substation voltage management and ensure the power quality and power supply security of rural power grids.

[0033] The foregoing is merely an embodiment of the present invention and is not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A voltage over-limit control method based on user active and passive responsibility division, characterized by: The following steps are included: S1. Periodically obtain electrical data including real-time node voltages of distributed photovoltaic nodes and adjustable distributed photovoltaic nodes through the substation data acquisition device. , active and reactive loads and distributed photovoltaic power generation, where i is the branch number and j is the node number, and the electrical data is sent to the substation terminal; S2, the substation terminal determines the real-time node voltage based on the received electrical data Whether it is out of limit, if there is an out of limit node, go to the next step S3; otherwise return to step S1; S3. Calculating User Active Responsibility Passive liability of users ; S4, user active responsibility obtained from step S3 Passive liability of users , establish the objective function with the goal of minimizing line loss and minimizing distributed photovoltaic active power reduction, and solve to obtain the regulation amount of distributed photovoltaic active and reactive power; S5. The substation terminal transmits the active and reactive power regulation instructions to each adjustable distributed photovoltaic node; S6. Each adjustable distributed photovoltaic node performs active and reactive power regulation according to active and reactive regulation quantity instructions.

2. The voltage over-limit control method based on user active and passive responsibility division according to claim 1 is characterized by: In step S2, the substation terminal determines the real-time node voltage based on the received electrical data. Whether it exceeds the limit, specifically, the real-time node voltage Greater than the voltage safe operation threshold U max If , there is an out-of-limit node; otherwise, there is no out-of-limit node.

3. The voltage over-limit control method based on user active and passive responsibility division according to claim 1 is characterized in that: In step S3, calculate the user's active responsibility When the net load is larger, the user's active responsibility is greater; when calculating the user's passive responsibility When the user is closer to the end of the area, the passive responsibility is greater.

4. The voltage over-limit control method based on user active and passive responsibility division according to any one of claims 1 to 3, characterized in that: In step S3, calculate the user's active responsibility Passive liability of users , specifically, S21. User active responsibility of node (i, j) Related to the net power generation of the node (i, j), calculate the user's active responsibility : ， in, is the active power output by the photovoltaic inverter connected to node (i, j), is the active power consumed by the load at node (i, j); S21. User passive responsibility of node (i, j) Related to the location of the node (i, j), calculate the user's passive responsibility : ， in, , are the minimum node and maximum node of branch i respectively.

5. The voltage over-limit control method based on user active and passive responsibility division according to any one of claims 1 to 3, characterized in that: In step S4, an objective function is established with the goal of minimizing line loss and minimizing distributed photovoltaic active power reduction. : ， in, , They represent the constraint functions, is the output active power of distributed photovoltaic at node (i, j), is the active load of node (i, j), is the current flowing through the node (i, j), is the resistance value of the line between node (i, j) and the previous node; The constraints are: ， in, is the real-time node voltage of node (i, j), is the voltage at the head end of the station, 、 is the equivalent power consumption of node (i, j), 、 is the line parameter, , The lower and upper limits of the safe operating range of the node voltage in the distribution station area are: is the active power output by the photovoltaic inverter connected to node (i, j), is the reactive power output by the photovoltaic inverter connected to node (i, j), is the rated capacity of the PV inverter connected to node (i, j).

6. A voltage over-limit management system based on user active and passive responsibility division using the method according to any one of claims 1 to 5, characterized in that: Including area data acquisition device, area terminal, distributed photovoltaic nodes and adjustable distributed photovoltaic nodes, Substation data acquisition device: periodically obtains electrical data excluding distributed photovoltaic nodes and adjustable distributed photovoltaic nodes, including real-time node voltage , active and reactive loads and distributed photovoltaic power generation, where i is the branch number and j is the node number, and the electrical data is sent to the substation terminal; Substation terminal: Determine the real-time node voltage based on the received electrical data Whether it exceeds the limit, when there is an exceeding limit node, calculate the user's active responsibility Passive liability of users , establish an objective function with the goal of minimizing line loss and distributed photovoltaic active power reduction, and solve to obtain the adjustment amount of distributed photovoltaic active and reactive power; transmit the active and reactive adjustment amount instructions to each adjustable distributed photovoltaic node; otherwise, the substation data acquisition device continuously collects electrical data from each node; Adjustable distributed photovoltaic nodes: Active and reactive power are adjusted according to active and reactive power regulation instructions.

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