Voltage consumption coordination control method and device for distributed photovoltaic access transformer area of power grid

Abstract

The invention relates to the technical field of power system automation, and discloses a voltage consumption coordination control method and device for a power grid distributed photovoltaic access district, and the method comprises the steps: carrying out the analysis of a district voltage consumption operation region: carrying out the real-time monitoring and calculation of the district, and carrying out the analysis of the voltage consumption operation region; and area-level local voltage consumption control: carrying out real-time analysis on the out-of-limit operation area, and calculating according to adjustment strategies of different operation areas to obtain a total active power demand adjustment amount or a total reactive power demand adjustment amount. By detecting the operation state of the area in real time, the local voltage consumption control of the out-of-limit area and the superior coordination control of the normal area are realized; the method comprises the following steps of: performing multi-inverter coordinated closed-loop control according to the states of the inverters, unifying data standards, mining data values to realize scientific decision, improving the reliability of the system by virtue of dual mechanisms, and relying on a visual interactive innovation operation and maintenance mode, thereby ensuring that the voltage and load rate of a distributed photovoltaic access station area are qualified and realizing maximum consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of power system automation, and particularly to a voltage absorption coordination control method and device for a distribution network area with distributed photovoltaic access to the power grid. Background Technique

[0002] In recent years, with the advancement of the "dual carbon" goal, the penetration rate of distributed photovoltaic power generation in the distribution network has been continuously increasing, and a large number of distributed photovoltaic power sources have been connected to the distribution network area of the power grid. However, the power generation power of distributed photovoltaics is affected by factors such as light intensity and weather changes, and has significant intermittency and volatility. This characteristic makes the operating conditions of the distribution network area of the power grid complex, and the voltage and load rate of the distribution transformer in the area are prone to abnormal fluctuations. In the traditional operation management of the distribution network, there is a lack of effective countermeasures for the impact brought by the access of distributed photovoltaics. On the one hand, the voltage absorption control strategy is relatively single, difficult to be flexibly adjusted according to the actual operating state of the area, and the voltage absorption coordination control mechanism between the distribution network and the superior distribution automation system is imperfect, resulting in many problems in the transmission and execution of control commands; on the other hand, the data management and analysis capabilities are weak, the data standards between different devices and systems are not unified, the data transmission accuracy rate is low, and it is difficult to effectively utilize the operating data. At the same time, there is a lack of systematic monitoring and control of the operating state of key equipment such as photovoltaic inverters, and the controllability evaluation of equipment is insufficient, easily resulting in ineffective regulation and misoperation. In terms of operation and maintenance management, the traditional manual inspection and operation mode relies on the experience of operation and maintenance personnel, lacks intuitive visual display and intelligent fault diagnosis and alarm functions, resulting in low operation and maintenance efficiency and high labor costs. Summary of the Invention

[0003] The purpose of the present invention is to provide a voltage absorption coordination control method and device for a distribution network area with distributed photovoltaic access to the power grid, so as to solve the problems in the above background technique that with the increase in the penetration rate of distributed photovoltaics in the distribution network under the "dual carbon" goal, the intermittency and volatility of its power generation lead to abnormal fluctuations in the voltage and load rate of the distribution transformer in the area, while the traditional distribution network has single voltage absorption control, imperfect superior-subordinate coordination mechanism, weak data management and analysis, and inefficient equipment control and operation and maintenance.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A voltage absorption coordination control method for a distribution network area with distributed photovoltaic access to the power grid, which is applied to a voltage absorption coordination control system at the distribution network area level; the method includes:

[0006] Analysis of the voltage absorption operation area of the area: including real-time monitoring and calculation of the area and analysis of the voltage absorption operation area;

[0007] Local voltage absorption control at the substation area level: Conduct real-time analysis on the over-limit operation area, calculate according to the adjustment strategies of different operation areas, and obtain the total active power demand adjustment amount or the total reactive power demand adjustment amount;

[0008] Superior voltage absorption coordination control: For the normal operation area, detect the effectiveness of the superior coordination instruction, analyze the superior coordination instruction, and conduct coordination strategy calculation with the constraints of the substation area voltage limit and the load rate limit to obtain the total active power demand adjustment amount or the total reactive power demand adjustment amount;

[0009] Multi-PV inverter coordination control: Based on the operation status and adjustment ability information of the PV inverters, find the adjustable inverters, and distribute the demand adjustment amount to each adjustable inverter according to the set distribution rules;

[0010] Generate and issue control instructions: According to the adjustment amount and adjustment instruction type of the inverter, formulate the adjustment control strategy of the inverter, convert the generated control strategy into specific control instructions, and issue the instructions to the PV inverter through the communication network to achieve closed-loop control of its output.

[0011] As a preferred technical solution of the present invention, the real-time monitoring and calculation in the substation area voltage absorption operation area analysis include: real-time data monitoring in the substation area, real-time calculation of the distribution transformer load rate, and operation monitoring of the system, distribution transformer, and PV inverter, specifically:

[0012] Real-time data in the substation area: Three-phase voltage, three-phase current, active power, reactive power, power factor;

[0013] Real-time data of the inverter: Three-phase voltage, three-phase current, active power, reactive power;

[0014] Real-time load rate: The real-time load rate is calculated by dividing the real-time current by the allowed maximum current;

[0015] Voltage qualification rate: According to the voltage limit range and voltage acquisition data, the voltage qualification rate from zero to the current moment is calculated in real time;

[0016] System operation information: Commissioning status, blocking status, open-loop, closed-loop control mode;

[0017] Distribution transformer operation information: Open-loop, closed-loop control mode, voltage upper limit, voltage lower limit;

[0018] Inverter operation information: Remote status, operation status, blocking status, capacity, reactive power target value, active power target value, reactive power target update time, active power target update time.

[0019] As a preferred technical solution of the present invention, the analysis of the voltage absorption operation area includes: comparing the real-time monitored voltage and load rate with the preset limits, and determining the operation area of the transformer area according to the ranges where the voltage and load rate are located. The operation area refers to the nine areas divided by the upper and lower limits of the transformer area voltage and the upper and lower limits of the load rate in the voltage-load rate plane graph, which are, in sequence, the upper limit of voltage and the upper limit of load rate, the upper limit of voltage and normal load rate, the upper limit of voltage and the lower limit of load rate, normal voltage and the upper limit of load rate, normal voltage and normal load rate, normal voltage and the lower limit of load rate, the lower limit of voltage and the upper limit of load rate, the lower limit of voltage and normal load rate, and the lower limit of voltage and the lower limit of load rate.

[0020] As a preferred technical solution of the present invention, the local voltage absorption control at the transformer area level refers to performing real-time calculation based on the expert adjustment rules according to the different over-limit operation areas where the current distribution transformer voltage absorption is located, and calculating the total active power or total reactive power demand.

[0021] As a preferred technical solution of the present invention, the coordinated control of the upper-level voltage absorption includes: when the current distribution transformer voltage absorption is in the normal operation area, parsing the upper-level instruction, detecting the validity of the upper-level instruction. When the upper-level instruction is valid, taking the voltage limit and load rate limit of the transformer area as constraints, performing the calculation of the coordinated control strategy for the upper-level voltage absorption, and calculating the total active power or total reactive power demand of the transformer area. The validity judgment of the coordinated instruction mainly includes timeliness and correctness. For the judgment of timeliness, obtain the time of the coordinated instruction and judge whether the time is overdue. If so, the instruction is overdue and invalid. If not, the timeliness of the instruction meets the requirements. For the correctness judgment, parse the coordinated instruction. If the coordinated instruction is greater than the actual adjustment ability of the transformer area, judge the instruction invalid. If the coordinated instruction is less than the adjustment dead zone of the transformer area, judge the instruction invalid.

[0022] As a preferred technical solution of the present invention, the coordinated control of multiple photovoltaic inverters, according to the operating state of the inverters, adjustment ability information, adjustment step size, and adjustment dead zone control information, searches for adjustable inverters, allocates the total active power or total reactive power adjustment amount, provides multiple allocation methods, such as the installed capacity ratio, theoretical output ratio, sharing factor ratio, manual priority sorting, and utilization hour sorting. According to the set allocation method, calculate and allocate the total active power or total reactive power adjustment amount to each adjustable inverter to obtain the adjustment amount of each inverter;

[0023] According to the operating state and locking state of the photovoltaic inverters, search for the inverters with the operating state of being put into operation and the locking state of being unlocked. According to the adjustment ability information of the photovoltaic inverters, if the adjustment direction of the total adjustment amount is to increase and the upper adjustment ability of the inverter is less than the adjustment dead zone, the inverter is uncontrollable. If the adjustment direction of the total adjustment amount is to decrease and the lower adjustment ability is less than the adjustment dead zone, the inverter cannot be adjusted and does not bear the adjustment amount;

[0024] The control instruction is generated and sent down. The adjustment amounts and adjustment instruction types of each inverter are used to generate the control strategy of the inverter, which is transformed into specific active or reactive remote adjustment setpoint control instructions for the inverter. These instructions are sent down to the PV inverter through the communication network to achieve closed-loop control of its output.

[0025] The voltage absorption and coordination control device for grid-distributed PV access to the distribution area in the present invention includes: a distribution area voltage absorption operation area analysis module, which is used for real-time monitoring and calculation of the distribution area and analysis of the voltage absorption operation area to obtain the current operation area of the distribution transformer voltage absorption in the distribution area;

[0026] A local voltage absorption control module at the distribution area level, which is used for voltage absorption control in the over-limit operation area of the distribution area. It conducts real-time analysis on the over-limit operation area and calculates the total active power demand adjustment amount or total reactive power demand adjustment amount according to the adjustment strategies in different operation areas;

[0027] A superior voltage absorption coordination control module, which is used for coordinated control with the superior voltage absorption system. For the normal operation area, it detects the effectiveness of the superior coordination instruction, analyzes the superior coordination instruction, and conducts coordinated strategy calculation with the voltage limit value and load rate limit value of the distribution area as constraints to obtain the total active power demand adjustment amount or total reactive power demand adjustment amount;

[0028] A multi-PV inverter coordinated control module, which is used to allocate the total demand adjustment amount. According to the operation status and adjustment ability information of the PV inverter, it searches for adjustable inverters and allocates the demand adjustment amount to each adjustable inverter according to the set allocation rules;

[0029] A control instruction generation and sending-down module, which is used for the generation and execution of control instructions. According to the adjustment amount and adjustment instruction type of the inverter, it formulates the adjustment control strategy of the inverter, transforms the generated control strategy into specific control instructions, and sends the instructions down to the PV inverter through the communication network to achieve closed-loop control of its output.

[0030] As a preferred technical solution of the present invention, it further includes an operation information monitoring specification module, which is used to standardize the monitoring information of the distribution area and the interaction information between the distribution area and the inverter, covering the operation status parameters of the system, distribution transformer and inverter. The superior voltage absorption coordination control module includes an instruction effectiveness determination unit, which judges the timeliness of the coordination instruction through the first judgment sub-module and judges the correctness of the instruction through the second judgment sub-module to ensure the effectiveness of the instruction. The multi-PV inverter coordinated control module includes a controllability evaluation unit, which comprehensively considers the operation status and adjustment ability conditions of the inverter through the controllability determination sub-module, the first judgment sub-module and the second judgment sub-module to determine whether the inverter undertakes the adjustment demand.

[0031] As a preferred technical solution of the present invention, the device further includes a data storage and analysis module, which includes: a historical data storage unit for storing historical data of the real-time monitoring and calculation information of the power distribution area, superior coordination instructions, control strategies, and inverter control instructions, supporting data archiving according to time series, and providing data support for long-term operation trend analysis;

[0032] An abnormal data marking unit for automatically identifying abnormal operation data such as voltage limit violation, load rate limit violation, and inverter failure, and adding marks to facilitate maintenance personnel to quickly locate abnormal periods;

[0033] A data analysis and processing unit, based on the stored historical data, uses data mining algorithms to analyze the voltage load rate fluctuation law and inverter regulation efficiency, and provides a decision-making basis for optimizing the regulation strategy and equipment configuration;

[0034] A data interface unit, which supports data interaction with an external database or a data analysis platform to achieve data sharing and remote call.

[0035] As a preferred technical solution of the present invention, the device further includes a human-computer interaction and visualization module, which includes: an information display interface unit for real-time displaying the voltage consumption operation area of the power distribution area, the real-time parameters of the distribution transformer and the inverter, and the execution status information of the regulation instruction in a graphical manner, supporting various visualization forms such as curves, charts, and maps;

[0036] An operation control unit that provides an artificial intervention interface. Maintenance personnel can manually issue regulation instructions, modify control parameters, or switch control modes through this unit;

[0037] An alarm prompt unit that issues an alarm through voice and pop-up windows when voltage limit violation, load rate limit violation, equipment failure, or abnormal instruction execution is detected, and displays detailed alarm information and processing suggestions;

[0038] A permission management unit that sets hierarchical operation permissions for different users to ensure the security and standardization of system operations and prevent misoperations from affecting system operation.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] 1. By detecting the voltage and load rate of the distribution transformer in the area in real time, analyzing the operating area where the voltage and load rate are located, if the operating area is in the over-limit area, calculate the local voltage absorption control strategy at the area level; if the operating area is in the normal area, detect the coordination control instruction of the superior distribution automation voltage absorption system in real time. If the instruction exists and is valid, parse the coordination control instruction of the superior, and calculate the coordination strategy with the voltage limit and load rate limit of the distribution transformer in the area as constraints to complete the coordination control with the superior voltage absorption system. The above control strategy calculates the total active power demand adjustment amount or the total reactive power demand adjustment amount of the area. Based on the operating status and adjustment ability information of each photovoltaic inverter in the area, search for adjustable inverters, and according to the set distribution rules, conduct the coordinated control of multiple photovoltaic inverters, allocate the demand adjustment amount to each adjustable inverter, and send control instructions for corresponding active or reactive power to the inverter to achieve closed-loop control. By implementing the voltage absorption coordination control of the area, ensure that the voltage and load rate of the area with distributed photovoltaic access are kept within the qualified range, and at the same time complete the coordination control with the superior to achieve the maximum absorption of distributed photovoltaic.

[0041] 2. Unify the data standard through the operation information monitoring specification module, and increase the data transmission accuracy rate to 99.9%; the data storage and analysis module realizes the full life cycle management of data. Through the in-depth mining and analysis of historical data, it can accurately master the key information of the voltage and load rate fluctuation rules and the inverter adjustment efficiency, provide a quantitative basis for the optimization of the adjustment strategy and the selection and configuration of equipment, transform the traditional control mode relying on experience into a data-driven scientific decision-making mode, reduce the equipment loss by 15%, extend the service life of the equipment, and improve the economy and reliability of the long-term operation of the system.

[0042] 3. Through the dual mechanisms of the instruction validity determination unit and the inverter controllability evaluation unit, greatly improve the reliability of the system operation. Conduct double verification of the timeliness and correctness of the superior instruction to improve the effective execution rate of the instruction; evaluate the inverter controllability in multiple dimensions to avoid ineffective adjustment and reduce the misoperation rate of the equipment. Effectively prevent control failures caused by incorrect instructions or misjudgment of equipment status, reduce the system failure risk, ensure the stable operation of the power grid, reduce the maintenance cost and power outage loss, and realize the innovation of the operation and maintenance mode through the human-computer interaction and visualization module. The intuitive graphical interface display improves the decision-making efficiency of the operation and maintenance personnel; the combination of manual intervention and hierarchical authority management provides a flexible operation space on the premise of ensuring system safety; the intelligent alarm and diagnosis function shortens the fault response time, quickly locates and processes abnormal problems. Significantly reduce the operation and maintenance threshold and labor cost, improve the operation and maintenance efficiency, promote the development of power grid operation and maintenance towards intelligence and high efficiency, and enhance the convenience and safety of power grid operation and maintenance. Brief Description of the Drawings

[0043] Figure 1It is the architecture step flow chart of the present invention;

[0044] Figure 2 It is the operation area division diagram of the present invention;

[0045] Figure 3 It is the structural framework diagram of the present invention;

[0046] Figure 4 It is the structural framework diagram of the operation information monitoring specification module, data storage and analysis module, and human-computer interaction and visualization module of the present invention.

[0047] In the figure: S101, analysis of the operation area for voltage absorption in the transformer area; S102, local voltage absorption control at the transformer area level; S103, coordinated control of voltage absorption at the upper level; S104, coordinated control of multiple photovoltaic inverters; S105, generation and issuance of control instructions; 301, module for analysis of the operation area for voltage absorption in the transformer area; 302, module for local voltage absorption control at the transformer area level; 303, module for coordinated control of voltage absorption at the upper level; 304, module for coordinated control of multiple photovoltaic inverters; 305, module for generation and issuance of control instructions; 4, operation information monitoring specification module; 5, data storage and analysis module; 501, historical data storage unit; 502, abnormal data marking unit; 503, data analysis and processing unit; 504, data interface unit; 6, human-computer interaction and visualization module; 601, information display interface unit; 602, operation control unit; 603, alarm prompt unit; 604, permission management unit. Detailed implementation manners

[0048] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] Please refer to Figures 1 - 4 , Figure 1 It is the step flow chart of the first embodiment of a method for coordinated control of voltage absorption in a transformer area with distributed photovoltaic access to the power grid of the present invention, which is applied to a coordinated control system for voltage absorption in a distribution network; the method steps include:

[0050] Step S101, analysis of the operation area for voltage absorption in the transformer area: including real-time monitoring and calculation of the transformer area, and analysis of the operation area for voltage absorption.

[0051] In the embodiment of the present invention, the real-time monitoring and calculation of the transformer area include real-time monitoring of the real-time data of the transformer area, real-time calculation of the load rate of the distribution transformer, and operation monitoring of the system, distribution transformer, and photovoltaic inverter. The specific information includes:

[0052] Real-time data of the transformer area: three-phase voltage, three-phase current, active power, reactive power, power factor;

[0053] Real-time data of the inverter: three-phase voltage, three-phase current, active power, reactive power;

[0054] Real-time load rate: The real-time load rate is calculated by dividing the real-time current by the maximum allowed current.

[0055] Voltage qualification rate: According to the voltage limit range and voltage acquisition data, the voltage qualification rate from zero to the current moment is calculated in real time.

[0056] System operation information: commissioning status, blocking status, open-loop / closed-loop control mode;

[0057] Distribution transformer operation information: open-loop / closed-loop control mode, voltage upper limit, voltage lower limit;

[0058] Inverter operation information: remote status, operation status, blocking status, capacity, reactive power target value, active power target value, reactive power target update time, active power target update time.

[0059] In the embodiment of the present invention, for the analysis of the voltage absorption operation area, the real-time monitored voltage and load rate are compared with the preset limits, and according to the ranges where the voltage and load rate are located, the operation status of the transformer area is divided into different areas.

[0060] For the analysis of the voltage absorption operation area, the real-time monitored voltage and load rate are compared with the preset limits, and according to the ranges where the voltage and load rate are located, the operation area of the transformer area is determined. The operation area refers to dividing the voltage-load rate plane graph of the upper and lower limits of the transformer area voltage and the upper and lower limits of the load rate into nine areas, as Figure 2 shown, in sequence: voltage above the upper limit and load rate above the upper limit, voltage above the upper limit and normal load rate, voltage above the upper limit and load rate below the lower limit, normal voltage and load rate above the upper limit, normal voltage and normal load rate, normal voltage and load rate below the lower limit, voltage below the lower limit and load rate above the upper limit, voltage below the lower limit and normal load rate, voltage below the lower limit and load rate below the lower limit; Step S102, local voltage absorption control at the transformer area level, which means based on the expert adjustment rules, real-time calculation is performed according to the different over-limit operation areas where the current distribution transformer voltage absorption is located, and the total active power or total reactive power demand is calculated. The expert adjustment rules for different areas are as Figure 2 shown.

[0061] Step S103, superior voltage absorption coordinated control. When the current distribution transformer voltage absorption is in the normal operation area, analyze the superior instruction and detect the validity of the superior instruction. When the superior instruction is valid, calculate the superior voltage absorption coordinated control strategy with the voltage limit and load rate limit of the transformer area as constraints, and calculate the total active or reactive power demand of the transformer area. The judgment of the validity of the coordination instruction mainly includes timeliness and correctness. Judgment of timeliness: Obtain the time of the coordination instruction and judge whether the time has expired; if so, the instruction is invalid due to timeout; if not, the timeliness of the instruction meets the requirements. Judgment of correctness: Analyze the coordination instruction. If the coordination instruction is greater than the actual adjustment ability of the transformer area, judge the instruction invalid; if the coordination instruction is less than the adjustment dead zone of the transformer area, judge the instruction invalid.

[0062] Step S104, multi-PV inverter coordinated control. According to the inverter operation status, adjustment ability information, adjustment step size, and adjustment dead zone control information, find the adjustable inverters. Allocate the total active or reactive power adjustment amount, and provide multiple allocation methods: installed capacity ratio, theoretical output ratio, sharing factor ratio, manual priority ranking, and utilization hour ranking. According to the set allocation method, calculate and allocate the total active or reactive power adjustment amount to each adjustable inverter, so as to obtain the adjustment amount of each inverter.

[0063] According to the operation status and locking status of the PV inverter, search for the inverters with the operation status of being put into operation and the locking status of being unlocked. According to the PV inverter adjustment ability information, if the adjustment direction of the total adjustment amount is to increase and the upper adjustment ability of the inverter is less than the adjustment dead zone, the inverter is uncontrollable; if the adjustment direction of the total adjustment amount is to decrease and the lower adjustment ability is less than the adjustment dead zone, the inverter is not adjustable and does not bear the adjustment amount.

[0064] Step S105, generate and issue control instructions. Convert the adjustment amount and adjustment instruction type of each inverter, and generate the control strategy of the inverter into specific active or reactive power remote adjustment setpoint control instructions for the inverter, and issue the instructions to the PV inverter through the communication network to achieve closed-loop control of its output.

[0065] By detecting the voltage and load rate of the distribution transformer in the area in real time, analyzing the operating area where the voltage and load rate are located, if the operating area is in the over-limit area, calculate the local voltage absorption control strategy at the area level; if the operating area is in the normal area, detect the coordination control instruction of the superior distribution automation voltage absorption system in real time. If the instruction exists and is valid, parse the coordination control instruction of the superior, and calculate the coordination strategy with the voltage limit and load rate limit of the distribution transformer in the area as constraints, so as to complete the coordination control with the superior voltage absorption system. The above control strategy calculates the total active power demand adjustment amount or the total reactive power demand adjustment amount of the area. According to the operating status and adjustment ability information of each photovoltaic inverter in the area, search for adjustable inverters, and distribute the demand adjustment amount to each adjustable inverter according to the set distribution rules, and issue control instructions for corresponding active or reactive power to the inverter to achieve closed-loop control. By implementing the voltage absorption coordination control of the area, ensure that the voltage and load rate of the area with distributed photovoltaic access are kept within the qualified range, and at the same time complete the coordination control with the superior to achieve the maximum absorption of distributed photovoltaic.

[0066] Please refer to Figure 3 [[ID=,5]] which shows a structural block diagram of an embodiment of a voltage absorption coordination control device for distributed photovoltaic access to a power grid area, and is applied to a distribution network voltage absorption coordination control system; it includes the following modules:

[0067] The area voltage absorption operating area analysis module 301 is used for real-time monitoring and calculation of the area and analysis of the voltage absorption operating area to obtain the current operating area of the voltage absorption of the distribution transformer in the area;

[0068] The local voltage absorption control module 302 at the area level is used for voltage absorption control in the over-limit operating area of the area. It conducts real-time analysis on the over-limit operating area and calculates the total active power demand adjustment amount or the total reactive power demand adjustment amount according to the adjustment strategies of different operating areas;

[0069] The superior voltage absorption coordination control module 303 is used for coordination control with the superior voltage absorption system. For the normal operating area, it detects the validity of the superior coordination instruction, parses the superior coordination instruction, and calculates the coordination strategy with the voltage limit and load rate limit of the area as constraints to obtain the total active power demand adjustment amount or the total reactive power demand adjustment amount;

[0070] The multi-photovoltaic inverter coordination control module 304 is used to distribute the total demand adjustment amount. According to the operating status and adjustment ability information of the photovoltaic inverter, it searches for adjustable inverters and distributes the demand adjustment amount to each adjustable inverter according to the set distribution rules;

[0071] The control instruction generation and issuance module 305 is used to generate and execute control instructions. Based on the inverter's regulation amount and regulation instruction type, it formulates the inverter's regulation control strategy, converts the generated control strategy into specific control instructions, and issues the instructions to the photovoltaic inverter via the communication network to achieve closed-loop control of its output.

[0072] The device uses the "Operational Area Analysis Module" to collect real-time data from the substation area and divide it into voltage absorption and operation areas. When in the out-of-limit area, the "Local Control Module" calculates the adjustment amount based on a preset strategy. If in the operational area, the "Superior Coordination Module" verifies and executes the superior's instructions. The "Inverter Allocation Module" selects adjustable inverters and assigns adjustment tasks. Finally, the "Instruction Execution Module" converts the control strategy into instructions, achieving closed-loop control of the inverter output, thereby dynamically adjusting the substation voltage and load rate. The integration of local autonomous regulation and superior instructions, combined with a precise inverter allocation mechanism, solves the problem of coordinated dynamic control of voltage fluctuations and voltage absorption in distributed photovoltaic access substations, improving voltage stability and absorption rate.

[0073] In an optional embodiment, the device further includes: an operation information monitoring specification module 4, which is used to standardize the monitoring information of the substation and the interactive information between the substation and the inverter, covering the system, distribution transformer and inverter operation status parameters; the upper-level voltage absorption coordination control module includes an instruction validity determination unit, which judges the timeliness of the coordination instruction through the first judgment submodule and judges the correctness of the instruction through the second judgment submodule to ensure that the instruction is valid; the multi-inverter coordination control module includes a controllability evaluation unit, which comprehensively considers the inverter operation status and adjustment capability conditions through the controllable determination submodule, the first judgment submodule and the second judgment submodule to determine whether the inverter bears the adjustment demand;

[0074] The "Operation Information Monitoring Specification Module" standardizes the operating data formats of the system, distribution transformers, and inverters to ensure accurate information exchange; the submodules of the "Superior Coordination Module" verify superior instructions through the dual dimensions of timeliness and correctness to avoid interference from invalid instructions; the submodules of the "Inverter Allocation Module" judge the controllability of the inverter through operating status and adjustment capability conditions to ensure the accurate issuance of adjustment tasks, and introduce multi-dimensional data specifications and instruction verification mechanisms. By refining the inverter controllability evaluation standards, it solves the problems of data confusion, instruction misexecution, and invalid equipment adjustment in traditional control, thereby improving the reliability and adjustment accuracy of the system.

[0075] In an optional embodiment, the device further includes a data storage and analysis module 5, whose specific structure and functions are as follows: a historical data storage unit 501, which is used to store information on real-time monitoring and calculation of the substation, superior coordination instructions, control strategies, and historical data of inverter control instructions, supports data archiving according to time series, and provides data support for long-term operation trend analysis;

[0076] An abnormal data marking unit 502, which is used to automatically identify abnormal operation data such as voltage over-limit, load rate over-limit, and inverter failure, and add marks to facilitate the operation and maintenance personnel to quickly locate the abnormal period;

[0077] A data analysis and processing unit 503, based on the stored historical data, uses data mining algorithms to analyze the voltage and load rate fluctuation rules and the inverter adjustment efficiency, and provides a decision-making basis for optimizing the adjustment strategy and equipment configuration;

[0078] A data interface unit 504, which supports data interaction with an external database or a data analysis platform to achieve data sharing and remote call;

[0079] The "data storage and analysis module" continuously records the operation data of the power distribution area and equipment. The "abnormal marking unit" monitors and marks abnormal events in real time. The "analysis and processing unit" analyzes the voltage and load rate fluctuation rules and equipment efficiency through data mining algorithms. The "data interface unit" supports data sharing and provides data support for optimizing the adjustment strategy and equipment maintenance, realizing a closed-loop process from historical data to decision-making. Deeply integrating the data storage and analysis function into the voltage control process, and realizing "data-driven" strategy optimization through historical data mining, which is different from the traditional experience-dependent control method, and provides a scientific basis for the long-term stable operation of the system.

[0080] In an optional embodiment, the device further includes a human-computer interaction and visualization module 6, and the specific structure and functions are as follows: An information display interface unit 601, which visually displays the voltage absorption operation area of the power distribution area, the real-time parameters of the distribution transformer and the inverter, and the execution status information of the adjustment instruction in real time in a graphical manner, and supports various visualization forms such as curves, charts, and maps;

[0081] An operation control unit 602, which provides an artificial intervention interface. The operation and maintenance personnel can manually issue adjustment instructions, modify control parameters, or switch control modes through this unit;

[0082] An alarm prompt unit 603, when detecting voltage over-limit, load rate over-limit, equipment failure, or abnormal instruction execution, issues an alarm through voice and pop-up windows, and displays detailed alarm information and handling suggestions;

[0083] A permission management unit 604, which sets hierarchical operation permissions for different users to ensure the security and standardization of system operations and prevent misoperations from affecting system operation;

[0084] The "Human-Machine Interaction and Visualization Module" displays the system status in real time through a graphical interface, and maintenance personnel can manually intervene through the "Operation Control Unit"; the "Alarm Prompt Unit" gives instant warnings for abnormal events and provides handling suggestions; the "Permission Management Unit" ensures operation safety through hierarchical permission control. Each unit works in coordination to achieve efficient human-machine interaction and intelligent operation and maintenance. An integrated interaction system integrating visual monitoring, manual intervention, intelligent alarm, and permission management is constructed, breaking the "black box" mode of traditional control devices, significantly improving operation and maintenance efficiency, reducing human operation risks, and enhancing system security and usability.

[0085] In this invention, by detecting the voltage and load rate of the distribution transformer in the substation area in real time and analyzing the operating area where the voltage and load rate are located, if the operating area is in the over-limit area, the calculation of the local voltage absorption control strategy at the substation area level is carried out; if the operating area is in the normal area, the coordinated control instruction of the voltage absorption system with the superior distribution automation is detected in real time. If the instruction exists and is valid, the coordinated control instruction of the superior is parsed, and the coordinated strategy calculation is carried out with the voltage limit value and load rate limit value of the distribution transformer in the substation area as constraints to complete the coordinated control with the superior voltage absorption system. The above control strategy calculates the total active power demand adjustment amount or total reactive power demand adjustment amount of the substation area. Based on the operating status and adjustment ability information of each photovoltaic inverter in the substation area, the adjustable inverters are searched, and according to the set distribution rules, the coordinated control of multiple photovoltaic inverters is carried out, and the demand adjustment amount is allocated to each adjustable inverter, and a control instruction for controlling the corresponding active or reactive power is sent to the inverter to achieve closed-loop control. By implementing the coordinated control of voltage absorption in the substation area, it is ensured that the voltage and load rate of the substation area with distributed photovoltaic access are kept within the qualified range, and at the same time, the coordinated control with the superior is completed to achieve the maximum absorption of distributed photovoltaic.

[0086] Through a pioneering hierarchical collaborative control architecture, dynamic and precise voltage regulation is achieved. The proposed core control architecture utilizes a hierarchical collaborative mechanism, breaking through the limitations of traditional single-mode regulation. The "Substation Voltage Accommodation Operation Area Analysis Module" divides operating areas in real time. Combined with the over-limit autonomous regulation of the "Substation-Level Local Voltage Accommodation Control Module" and the command coordination of the "Superior Voltage Accommodation Coordination Control Module," differentiated responses are achieved under different operating conditions. Simultaneously, the "Multi-Inverter Coordination Control Module" precisely allocates regulation tasks based on inverter status, collaborating with the "Control Command Generation and Issuance Module" to form a closed-loop control system. This architecture not only resolves the voltage and load rate over-limit issues caused by distributed photovoltaic integration but also significantly enhances the system's adaptability to complex operating conditions. This improves the voltage compliance rate while achieving maximum absorption, providing an innovative, systematic solution for substation voltage stability and absorption. Innovations are achieved through both data standardization and in-depth analysis. The "Operation Information Monitoring Specification Module" unifies the data exchange standards between the system, distribution transformers, and inverters, standardizing the transmission format for over 30 key pieces of information, including system operational status, real-time distribution transformer parameters, and inverter target values. This completely resolves the data exchange issues inherent in traditional control systems and improves data transmission accuracy. The "Data Storage and Analysis Module" establishes a comprehensive management system, from historical data archiving and anomaly marking to algorithm mining. By storing over five years of operating data and utilizing machine learning algorithms to analyze the correlation between voltage fluctuations and inverter regulation, it optimizes regulation strategies, providing a scientific and quantitative basis for long-term system optimization and achieving a fundamental shift from experience-driven to data-driven approaches. By implementing dual safeguards at the command execution and device management levels, the "Superior Voltage Absorption Coordinated Control Module" utilizes a "timeliness assessment submodule," such as setting a command validity limit of 10 minutes, and a "correctness assessment submodule" to compare commands with the actual regulation capabilities of the substation. This prevents control failures caused by expired commands or over-capacity execution, thereby improving the effectiveness of command execution. The "Multi-Inverter Coordinated Control Module" comprehensively evaluates inverter controllability using six indicators: device operating status, lockout status, and regulation deadband. This ensures that regulation tasks are assigned only to devices that meet the requirements, eliminating ineffective regulation and reducing device malfunction rates. This mechanism significantly enhances system coordination with higher-level commands and the reliability of local device control, improving overall operational stability. The built-in "Human-Machine Interaction and Visualization Module" revolutionizes the operation of traditional control devices. The information display interface unit uses graphical and dynamic curve visualization technology to intuitively present voltage absorption operating areas and device operating information, enhancing decision-making efficiency for operation and maintenance personnel. The operation control unit supports manual intervention and parameter modification. Combined with the hierarchical permission settings of the permission management unit (e.g., administrator, operator, and viewer), this provides flexible control capabilities while ensuring system security. The alarm prompt unit integrates voice alarms. When voltage exceeds the limit, load factor exceeds the limit, or inverter fault is detected, it issues an alarm within 3 seconds and provides a solution, shortening fault response time.This module realizes the deep integration of "automatic control + intelligent operation and maintenance", providing a demonstration solution for the intelligent upgrade of the power grid. Therefore, through the collaborative innovation of multiple modules, systematic breakthroughs have been achieved in architecture design, data management, instruction execution, and operation and maintenance models, effectively solving the problem of coordinated control of voltage accommodation in the distribution area with distributed photovoltaic access, and possessing remarkable technological advancement and engineering application value.

[0087] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A voltage absorption coordination control method for a distributed photovoltaic access area in a power grid, characterized in that: Applied to the distribution network substation-level voltage absorption coordinated control system; the method includes: Substation voltage absorption operation area analysis: including substation real-time monitoring and calculation, voltage absorption operation area analysis; Substation-level local voltage absorption control: Real-time analysis is performed on out-of-limit operating areas, and the total active power demand adjustment or total reactive power demand adjustment is calculated based on the regulation strategy of different operating areas. Coordinated control of upper-level voltage absorption: For the normal operating area, the system detects the validity of the upper-level coordination instructions, analyzes the upper-level coordination instructions, and calculates the coordination strategy based on the substation voltage limit and load rate limit to obtain the total active power demand adjustment or total reactive power demand adjustment. Coordinated control of multiple photovoltaic inverters: Based on the operating status and regulation capability information of the photovoltaic inverters, the system searches for adjustable inverters and distributes the required regulation amount to each adjustable inverter according to the set allocation rules; Generate and issue control instructions: Based on the inverter's regulation quantity and regulation instruction type, formulate the inverter's regulation control strategy, convert the generated control strategy into specific control instructions, and issue the instructions to the photovoltaic inverter through the communication network to achieve closed-loop control of its output.

2. The voltage absorption coordination control method for distributed photovoltaic access areas in a power grid according to claim 1 is characterized in that: The real-time monitoring and calculation of the substation in the substation voltage absorption operation area analysis includes: real-time data monitoring of the substation, real-time calculation of the distribution transformer load rate, and operation monitoring of the system, distribution transformer, and photovoltaic inverter. Specifically: Real-time data of the substation: three-phase voltage, three-phase current, active power, reactive power, and power factor; Inverter real-time data: three-phase voltage, three-phase current, active power, reactive power; Real-time load rate: The real-time load rate is calculated by dividing the real-time current by the maximum allowable current; Voltage qualification rate: The voltage qualification rate from zero to the current moment is calculated in real time based on the voltage limit range and voltage acquisition data; System operation information: commissioning status, locking status, open-loop and closed-loop control modes; Distribution transformer operation information: open-loop and closed-loop control modes, voltage upper limit and voltage lower limit; Inverter operation information: remote status, operating status, blocking status, capacity, reactive power target value, active power target value, reactive power target update time, active power target update time.

3. The voltage absorption coordination control method for distributed photovoltaic access areas in a power grid according to claim 1, characterized in that: The voltage absorption operation area analysis includes: comparing the voltage and load rate monitored in real time with the preset limits, and determining the operation area of the substation according to the range of the voltage and load rate. The operation area refers to dividing the voltage-load rate plane diagram of the substation voltage upper and lower limits and load rate upper and lower limits into nine areas, which are, the higher the voltage, the higher the upper limit, the load rate is normal, the higher the upper limit, the load rate is lower, the normal voltage, the higher the upper limit, the load rate is normal, the normal voltage, the lower the lower limit, the load rate is normal, the lower the lower limit, the lower the lower limit, the load rate is normal, the lower the lower limit, the lower the lower limit, the load rate is normal, and the lower the lower limit, the load rate is lower.

4. The voltage absorption coordination control method for distributed photovoltaic access areas in a power grid according to claim 1, characterized in that: Substation-level local voltage absorption control refers to real-time calculation based on expert adjustment rules according to the different over-limit operation areas of the current distribution transformer voltage absorption, and calculates the total active or total reactive power demand.

5. The voltage absorption coordination control method for distributed photovoltaic access areas in a power grid according to claim 1, characterized in that: The coordinated control of the upper-level voltage absorption includes: the current distribution transformer voltage absorption is in the normal operating area, the upper-level instructions are analyzed, and the validity of the upper-level instructions is detected. When the upper-level instructions are valid, the upper-level voltage absorption coordinated control strategy is calculated with the substation voltage limit and load rate limit as constraints, and the total active or total reactive power demand of the substation is calculated. The validity judgment of the coordinated instruction mainly includes timeliness and correctness. The timeliness judgment is to obtain the time of the coordinated instruction and judge whether the time has timed out. If so, the instruction is invalid due to timeout. If not, the instruction timeliness meets the requirements, correctness judgment, and analysis of the coordinated instruction. If the coordinated instruction is greater than the actual adjustment capability of the substation, the instruction is judged to be invalid. If the coordinated instruction is less than the adjustment dead zone of the substation, the instruction is judged to be invalid.

6. The voltage absorption coordination control method for distributed photovoltaic access areas in a power grid according to claim 1, characterized in that: Coordinated control of multiple photovoltaic inverters: Based on the inverter's operating status, regulation capability, regulation step size, and regulation dead zone control information, it finds adjustable inverters and allocates total active or total reactive regulation. It provides multiple allocation methods: installed capacity ratio, theoretical output ratio, sharing factor ratio, manual priority sorting, and utilization hour sorting. Based on the set allocation method, the total active or total reactive regulation is calculated and allocated to each adjustable inverter to obtain the regulation amount of each inverter. According to the operating status and blocking status of the PV inverter, search for inverters with the operating status in operation and the blocking status in unlocked. Based on the PV inverter's regulation capability information, if the total regulation amount is increasing and the inverter's upper regulation capability is less than the regulation dead zone, the inverter is uncontrollable. If the total regulation amount is decreasing and the lower regulation capability is less than the regulation dead zone, the inverter cannot be adjusted and does not bear the regulation amount. The control instructions are generated and issued, and the adjustment amount and adjustment instruction type of each inverter are converted into the inverter's specific active or reactive remote adjustment set point control instructions. The instructions are sent to the photovoltaic inverter through the communication network to achieve closed-loop control of its output.

7. The voltage absorption coordination control device for the distributed photovoltaic access area of the power grid is characterized by: include: The substation voltage absorption operation area analysis module (301) is used for real-time monitoring and calculation of the substation, voltage absorption operation area analysis, and obtaining the current substation distribution transformer voltage absorption operation area; The local voltage absorption control module (302) at the substation level is used for voltage absorption control in the substation's over-limit operation area, performs real-time analysis on the over-limit operation area, and calculates the total active power demand adjustment amount or the total reactive power demand adjustment amount based on the adjustment strategy of different operation areas; The upper voltage absorption coordination control module (303) is used for coordination control with the upper voltage absorption system, detecting the validity of the upper coordination instruction for the normal operating area, parsing the upper coordination instruction, and calculating the coordination strategy with the voltage limit and load rate limit of the substation area as constraints to obtain the total active demand adjustment amount or the total reactive demand adjustment amount; A multi-photovoltaic inverter coordination control module (304) is used to allocate the total demand regulation amount, find the adjustable inverter according to the operating status and regulation capability information of the photovoltaic inverter, and allocate the demand regulation amount to each adjustable inverter according to the set allocation rules; The control instruction generation and issuance module (305) is used for generating and executing control instructions, formulating an inverter regulation control strategy based on the inverter regulation amount and regulation instruction type, converting the generated control strategy into specific control instructions, and issuing the instructions to the photovoltaic inverter through the communication network to achieve closed-loop control of its output.

8. The voltage absorption coordination control device for distributed photovoltaic access to a power grid according to claim 7, characterized in that: The system also includes an operation information monitoring specification module (4) for standardizing the monitoring information of the substation and the interactive information between the substation and the inverter, covering the system, distribution transformer and inverter operation status parameters. The upper-level voltage absorption coordination control module (303) includes an instruction validity judgment unit, which judges the timeliness of the coordination instruction through the first judgment submodule and judges the correctness of the instruction through the second judgment submodule to ensure the validity of the instruction. The multi-photovoltaic inverter coordination control module (304) includes a controllability evaluation unit, which comprehensively considers the inverter operation status and regulation capability conditions through the controllable determination submodule, the first judgment submodule and the second judgment submodule to determine whether the inverter meets the regulation requirements.

9. The voltage absorption coordination control device for distributed photovoltaic access to a power grid according to claim 7, characterized in that: The device also includes a data storage and analysis module (5), including: a historical data storage unit (501), which is used to store information on real-time monitoring and calculation of the substation, superior coordination instructions, control strategies, and historical data of inverter control instructions, supports data archiving according to time series, and provides data support for long-term operation trend analysis; An abnormal data marking unit (502) is used to automatically identify abnormal operation data such as voltage exceeding the limit, load rate exceeding the limit, and inverter failure, and add a mark to facilitate operation and maintenance personnel to quickly locate the abnormal period; A data analysis and processing unit (503) uses a data mining algorithm to analyze voltage fluctuation patterns, load rate fluctuation patterns, and inverter regulation efficiency based on stored historical data, providing a decision basis for optimizing regulation strategies and equipment configuration; The data interface unit (504) supports data interaction with an external database or data analysis platform to achieve data sharing and remote calling.

10. The voltage absorption coordination control device for distributed photovoltaic access to a power grid according to claim 7, characterized in that: The device also includes a human-computer interaction and visualization module (6), including: an information display interface unit (601), which displays the voltage absorption operation area of the substation, the real-time parameters of the distribution transformer and inverter, and the execution status information of the adjustment instruction in a graphical manner in real time, and supports multiple visualization forms such as curves, charts, and maps; An operation control unit (602) provides a manual intervention interface, through which operation and maintenance personnel can manually issue adjustment instructions, modify control parameters or switch control modes; The alarm prompt unit (603) issues an alarm via voice or pop-up window when detecting voltage exceeding the limit, load rate exceeding the limit, equipment failure or abnormal instruction execution, and displays detailed alarm information and handling suggestions; The authority management unit (604) sets hierarchical operation authority for different users to ensure the safety and standardization of system operation and prevent misoperation from affecting system operation.

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