Voltage accommodation coordination control method and device for grid distributed photovoltaic access area

Abstract

The application relates to the technical field of power system automation, and discloses a voltage accommodation coordination control method and device for a power grid distributed photovoltaic access substation area, which comprises substation voltage accommodation operation area analysis, including substation real-time monitoring and calculation and voltage accommodation operation area analysis; substation-level local voltage accommodation control: real-time analysis is carried out on the over-limit operation area, total active demand regulation quantity or total reactive demand regulation quantity is obtained according to regulation strategy calculation of different operation areas, the application realizes local voltage accommodation control of the over-limit area and superior coordination control of the normal area by real-time detection of the substation operation state, and simultaneously performs multi-inverter coordinated closed-loop control according to the inverter state, unifies data standards, excavates data value to realize scientific decision-making, improves system reliability with the aid of a double mechanism, and innovates the operation and maintenance mode relying on visualization interaction, so that the voltage and load rate of the distributed photovoltaic access substation area are qualified and maximum accommodation is realized.

Description

Technical Field

[0001] This invention relates to the field of power system automation technology, specifically to a method and apparatus for voltage absorption coordination control of distributed photovoltaic access areas in power grids. Background Technology

[0002] In recent years, with the advancement of the "dual carbon" target, the penetration rate of distributed photovoltaic (PV) power generation in distribution networks has continued to increase, with a large number of distributed PV power sources connected to the distribution grid. However, the power generation of distributed PV is significantly affected by factors such as sunlight intensity and weather changes, exhibiting significant intermittency and volatility. This characteristic complicates the operating conditions of the distribution network, making it prone to abnormal fluctuations in transformer voltage and load rate. In traditional distribution network operation and management, there is a lack of effective means to address the impact of distributed PV integration. On the one hand, voltage absorption control strategies are relatively simple, making it difficult to flexibly adjust according to the actual operating status of the distribution area. The voltage absorption coordination control mechanism with the upper-level distribution automation system is imperfect, leading to numerous problems in the transmission and execution of control commands. On the other hand, data management and analysis capabilities are weak, with inconsistent data standards between different devices and systems, low data transmission accuracy, and difficulty in effectively utilizing operational data. Simultaneously, the monitoring and control of the operating status of key PV inverter equipment lacks systematicity, and the assessment of equipment controllability is insufficient, easily leading to ineffective adjustments and malfunctions. In terms of operation and maintenance management, the traditional manual inspection and operation mode relies on the experience of operation and maintenance personnel and lacks intuitive visualization 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 this invention is to provide a voltage absorption coordination control method and device for distributed photovoltaic (PV) grid access areas, in order to solve the problems mentioned in the background art, which are caused by the intermittency and volatility of PV power generation leading to abnormal fluctuations in the voltage and load rate of distribution transformers in the grid area, as the penetration rate of distributed PV in the distribution network increases under the "dual carbon" target. Traditional distribution networks also suffer from problems such as single voltage absorption control, imperfect coordination mechanism between upper and lower levels, weak data management and analysis, and inefficient equipment control and operation and maintenance.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A voltage absorption coordination control method for distributed photovoltaic (PV) grid access areas, applied to a distribution network area-level voltage absorption coordination control system; the method includes:

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

[0007] Local voltage absorption control at the transformer substation level: Real-time analysis is performed on over-limit operating areas, and the total active power demand adjustment or total reactive power demand adjustment is calculated based on the adjustment strategy of different operating areas.

[0008] Upper-level voltage absorption coordination control: For the normal operating area, detect the effectiveness of the upper-level coordination command, analyze the upper-level coordination command, and calculate the coordination strategy with the voltage limit of the transformer area and the load rate limit as constraints to obtain the total active power demand adjustment or the total reactive power demand adjustment.

[0009] Multi-PV inverter coordinated control: Based on the operating status and regulation capacity information of the PV inverters, the adjustable inverters are located, and the required regulation is distributed to each adjustable inverter according to the set allocation rules.

[0010] Control command generation and issuance: Based on the inverter's adjustment amount and adjustment command type, an inverter adjustment and control strategy is formulated. The generated control strategy is converted into specific control commands, which are then issued to the photovoltaic 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 of the distribution area in the analysis of the voltage absorption operation area includes: real-time data monitoring of the distribution area, real-time calculation of the distribution transformer load rate, and monitoring of the operation of the system, distribution transformers, and photovoltaic inverters, specifically:

[0012] Real-time data for the transformer area: three-phase voltage, three-phase current, active power, reactive power, and power factor;

[0013] Inverter real-time data: three-phase voltage, three-phase current, active power, reactive power;

[0014] Real-time load factor: The real-time load factor is calculated by dividing the real-time current by the maximum allowable current.

[0015] Voltage pass rate: The voltage pass rate from zero point to the current time is calculated in real time based on the voltage limit range and voltage acquisition data.

[0016] System operation information: commissioning status, interlocking status, open loop, closed loop control mode;

[0017] Distribution transformer operating information: open-loop and closed-loop control modes, upper voltage limit, and lower voltage limit;

[0018] Inverter operating information: remote status, operating status, lockout 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 voltage absorption operation area analysis includes: comparing the real-time monitored voltage and load rate with preset limits, and determining the operation area of ​​the transformer area according to the range of voltage and load rate. The operation area refers to the division of the voltage-load rate plane into nine areas, namely, the upper limit of voltage and the upper limit of load rate, the upper limit of voltage and the upper limit of load rate, the upper limit of load rate, the upper limit of voltage and the lower limit of load rate, the upper limit of load rate, the upper limit of voltage and the lower limit of load rate, the upper limit of load rate, the upper limit of load rate, the upper limit of load rate, the upper limit of load rate, the upper limit of load rate, the lower limit of load rate, the lower limit of load rate, the lower limit of load rate, the lower limit of load rate, and the lower limit of load rate.

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

[0021] As a preferred technical solution of the present invention, the upper-level voltage absorption coordination control includes: the current distribution transformer voltage absorption is in the normal operating range, parsing the upper-level command, detecting the validity of the upper-level command, and when the upper-level command is valid, calculating the upper-level voltage absorption coordination control strategy with the voltage limit and load rate limit of the distribution area as constraints, and calculating the total active or reactive power demand of the distribution area. The validity judgment of the coordination command mainly includes timeliness and correctness. For timeliness judgment, the time of obtaining the coordination command is used to determine whether the time has exceeded. If so, the command is invalid due to timeout; otherwise, the timeliness of the command meets the requirements. For correctness judgment, the coordination command is parsed. If the coordination command is greater than the actual regulation capacity of the distribution area, the command is determined to be invalid. If the coordination command is less than the regulation dead zone of the distribution area, the command is determined to be invalid.

[0022] As a preferred technical solution of the present invention, multi-photovoltaic inverter coordinated control, based on the inverter operating status, regulation capability information, regulation step size and regulation dead zone control information, finds adjustable inverters, allocates total active or total reactive power regulation, and provides multiple allocation methods, such as installed capacity ratio, theoretical output ratio, sharing factor ratio, manual priority ranking and utilization hours ranking. According to the set allocation method, the total active or total reactive power regulation is calculated and allocated to each adjustable inverter to obtain the regulation amount of each inverter.

[0023] Based on the operating status and lockout status of the photovoltaic inverter, search for inverters whose operating status is "on" and whose lockout status is "unlocked". Based on the photovoltaic inverter's regulation capacity information, if the regulation direction of the total regulation is increasing and the inverter's upper regulation capacity is less than the regulation dead zone, then the inverter is uncontrollable. If the regulation direction of the total regulation is decreasing and the lower regulation capacity is less than the regulation dead zone, then the inverter cannot be adjusted and does not bear the regulation amount.

[0024] Control commands are generated and issued, and the adjustment quantities and adjustment command types of each inverter are used to generate the inverter's control strategy, which is then transformed into specific active or reactive power remote adjustment control commands for the inverter. These commands are then sent to the photovoltaic inverters through the communication network to achieve closed-loop control of their output.

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

[0026] The transformer area-level local voltage absorption control module is used for voltage absorption control in the over-limit operation area of ​​the transformer area. It performs real-time analysis on the over-limit operation area, 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.

[0027] The upper-level voltage absorption coordination control module is used for coordination control with the upper-level voltage absorption system. For the normal operation area, it detects the validity of the upper-level coordination command, parses the upper-level coordination command, and calculates the coordination strategy with the voltage limit of the transformer area and the load rate limit as constraints to obtain the total active power demand adjustment or the total reactive power demand adjustment.

[0028] The multi-PV inverter coordination control module is used to allocate the total demand adjustment amount. Based on the operating status and adjustment capability information of the PV inverters, it finds the adjustable inverters and distributes the demand adjustment amount to each adjustable inverter according to the set allocation rules.

[0029] The control command generation and distribution module is used to generate and execute control commands. Based on the inverter's adjustment amount and the type of adjustment command, it formulates the inverter's adjustment and control strategy, converts the generated control strategy into specific control commands, and distributes the commands to the photovoltaic inverter through the communication network to achieve closed-loop control of its output.

[0030] As a preferred embodiment of the present invention, it further includes an operation information monitoring specification module, used to standardize the monitoring information of the transformer area and the interaction information between the transformer area and the inverter, covering the system, distribution transformer and inverter operating status parameters. The upper-level voltage absorption coordination control module includes an instruction validity determination unit, which determines the timeliness of the coordination instruction through a first judgment submodule and the correctness of the instruction through a second judgment submodule to ensure the instruction is valid. The multi-photovoltaic inverter coordination control module includes a controllability evaluation unit, which determines whether the inverter undertakes the regulation requirement by comprehensively considering the inverter operating status and regulation capability conditions through a controllability determination submodule, a first judgment submodule and a second judgment submodule.

[0031] As a preferred technical solution of the present invention, the device further includes a data storage and analysis module, including: a historical data storage unit, used to store historical data of information on real-time monitoring and calculation of the 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] The abnormal data marking unit is used to automatically identify abnormal operating data such as voltage exceeding limits, load rate exceeding limits, and inverter faults, and add markings to facilitate maintenance personnel to quickly locate abnormal periods.

[0033] The data analysis and processing unit, based on stored historical data, uses data mining algorithms to analyze voltage load rate fluctuation patterns and inverter regulation efficiency, providing a basis for decision-making to optimize regulation strategies and equipment configuration.

[0034] The data interface unit supports data interaction with external databases or data analysis platforms, enabling data sharing and remote access.

[0035] As a preferred technical solution of the present invention, the device further includes a human-computer interaction and visualization module, including: an information display interface unit, which displays the voltage absorption operation area of ​​the distribution area, the real-time parameters of the distribution transformer and inverter, and the status information of the adjustment command execution in a graphical manner in real time, and supports multiple visualization forms such as curves, charts, and maps;

[0036] The operation control unit provides a manual intervention interface, through which maintenance personnel can manually issue adjustment commands, modify control parameters, or switch control modes.

[0037] The alarm notification unit will issue alarms via voice and pop-up window when it detects voltage exceeding the limit, load rate exceeding the limit, equipment failure, or abnormal command execution, and will display detailed alarm information and handling suggestions.

[0038] The access control unit sets tiered access permissions for different users to ensure the security and standardization of system operations and prevent accidental operations from affecting system operation.

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

[0040] 1. By real-time monitoring of the distribution transformer voltage and load rate, the system analyzes the operating area of ​​the voltage and load rate. If the operating area is in an over-limit zone, a local voltage absorption control strategy is calculated at the distribution transformer level. If the operating area is in a normal zone, the system monitors the coordination control commands with the upper-level distribution automation voltage absorption system in real time. If the commands exist and are valid, the system parses the upper-level coordination control commands and calculates the coordination strategy using the distribution transformer voltage limit and load rate limit as constraints, thus completing the coordination control with the upper-level voltage absorption system. The above control strategy calculates the total active power demand adjustment or total reactive power demand adjustment of the distribution area. Based on the operating status and adjustment capacity information of each photovoltaic inverter in the distribution area, the system searches for adjustable inverters and performs coordinated control of multiple photovoltaic inverters according to the set allocation rules. The demand adjustment is allocated to each adjustable inverter, and control commands corresponding to active power or reactive power are issued to the inverters to achieve closed-loop control. By implementing voltage absorption coordination control in the distribution area, it is ensured that the voltage and load rate of the distribution area connected to distributed photovoltaic power are kept within the qualified range. At the same time, coordination control with the superior is completed to achieve maximum absorption of distributed photovoltaic power.

[0041] 2. By standardizing data through the operation information monitoring module, the data transmission accuracy is improved to 99.9%. The data storage and analysis module realizes full lifecycle management of data. Through in-depth mining and analysis of historical data, it can accurately grasp the fluctuation patterns of voltage and load rate and key information on inverter regulation efficiency, providing quantitative basis for regulation strategy optimization and equipment selection and configuration. This transforms the traditional experience-based control mode into a data-driven scientific decision-making mode, reducing equipment losses by 15%, extending equipment life, and improving the long-term economic efficiency and reliability of the system.

[0042] 3. The dual mechanism of the instruction validity judgment unit and the inverter controllability assessment unit significantly improves system operational reliability. Dual verification of the timeliness and correctness of superior instructions increases the effective execution rate; multi-dimensional assessment of inverter controllability avoids ineffective adjustments and reduces equipment malfunction rate. This effectively prevents control failures caused by instruction errors or misjudgments of equipment status, reduces system failure risks, ensures stable grid operation, lowers maintenance costs and power outage losses, and achieves operational model innovation through human-machine interaction and visualization modules. The intuitive graphical interface improves the decision-making efficiency of maintenance personnel; the combination of manual intervention and hierarchical permission management provides flexible operating space while ensuring system security; intelligent alarm and diagnostic functions shorten fault response time, quickly locate and handle abnormal problems. This significantly reduces the operational threshold and labor costs, improves operational efficiency, promotes the development of grid operation and maintenance towards intelligence and efficiency, and enhances the convenience and security of grid operation and maintenance. Attached Figure Description

[0043] Figure 1This is a flowchart illustrating the architectural steps of the present invention;

[0044] Figure 2 This is a diagram showing the division of the operating area of ​​the present invention;

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

[0046] Figure 4 This is a 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 diagram: S101, Voltage Absorption Operation Area Analysis of Transformer Area; S102, Local Voltage Absorption Control at the Transformer Area Level; S103, Upper-Level Voltage Absorption Coordination Control; S104, Coordination Control of Multiple Photovoltaic Inverters; S105, Control Command Generation and Issuance; 301, Voltage Absorption Operation Area Analysis Module; 302, Local Voltage Absorption Control Module at the Transformer Area Level; 303, Upper-Level Voltage Absorption Coordination Control Module; 304, Coordination Control Module of Multiple Photovoltaic Inverters; 305, Control Command Generation and Issuance Module; 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-Machine Interaction and Visualization Module; 601, Information Display Interface Unit; 602, Operation Control Unit; 603, Alarm Prompt Unit; 604, Access Control Unit. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0049] Please see Figures 1-4 , Figure 1 This is a flowchart illustrating the steps of a voltage absorption coordination control method for a distributed photovoltaic (PV) grid access area according to the present invention, applied to a distribution network voltage absorption coordination control system; the method steps include:

[0050] Step S101, Voltage Absorption Operation Area Analysis: This includes real-time monitoring and calculation of the transformer area and voltage absorption operation area analysis.

[0051] In this embodiment of the invention, real-time monitoring and calculation of the distribution area includes real-time data monitoring of the distribution area, real-time calculation of the distribution transformer load rate, and monitoring of the operation of the system, distribution transformers, and photovoltaic inverters. Specific information includes:

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

[0053] Inverter real-time data: three-phase voltage, three-phase current, active power, reactive power;

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

[0055] Voltage pass rate: The voltage pass rate is calculated in real time from zero point to the current time based on the voltage limit range and voltage acquisition data.

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

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

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

[0059] In this embodiment of the invention, voltage absorption operation area analysis compares the real-time monitored voltage and load rate with preset limits, and divides the operating status of the transformer area into different areas according to the range of voltage and load rate.

[0060] Voltage absorption operation area analysis compares the real-time monitored voltage and load rate with preset limits. Based on the range of voltage and load rate, the operating area of ​​the transformer substation is determined. The operating area refers to dividing the voltage-load rate plane diagram of the substation into nine regions, such as... Figure 2 As shown, the order is as follows: Voltage exceeding the upper limit, load rate exceeding the upper limit; Voltage exceeding the upper limit, load rate normal; Voltage exceeding the upper limit, load rate below the lower limit; Normal voltage, load rate exceeding the upper limit; Normal voltage, load rate normal; Normal voltage, load rate below the lower limit; Voltage below the lower limit, load rate exceeding the upper limit; Voltage below the lower limit, load rate normal; Voltage below the lower limit, load rate below the lower limit; Step S102, local voltage absorption control at the distribution area level, refers to real-time calculation based on expert adjustment rules according to the different over-limit operating areas where the current distribution transformer voltage absorption is located, to calculate the total active or total reactive power demand. The expert adjustment rules for different areas are as follows: Figure 2 As shown.

[0061] Step S103: Upper-level voltage absorption coordination control. The current distribution transformer voltage absorption is within the normal operating range. The upper-level command is parsed, and its validity is checked. When the command is valid, the upper-level voltage absorption coordination control strategy is calculated using the transformer area voltage limit and load rate limit as constraints, resulting in the total active or reactive power demand of the transformer area. The validity judgment of the coordination command mainly includes timeliness and correctness. Timeliness judgment: The time of obtaining the coordination command is checked to see if it has exceeded the time limit; if so, the command is invalid due to timeout; otherwise, the timeliness requirement is met. Correctness judgment: The coordination command is parsed. If the coordination command is greater than the actual regulation capacity of the transformer area, the command is considered invalid; if the coordination command is less than the regulation dead zone of the transformer area, the command is considered invalid.

[0062] Step S104: Multi-PV inverter coordinated control. Based on the inverter's operating status, regulation capacity information, regulation step size, and regulation dead zone control information, adjustable inverters are identified. Total active or reactive power regulation is allocated, providing 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, the total active or reactive power regulation is calculated and distributed to each adjustable inverter, thus obtaining the regulation amount for each inverter.

[0063] Based on the operating status and lockout status of the photovoltaic inverter, search for inverters whose operating status is "on" and whose lockout status is "unlocked". Based on the photovoltaic inverter's regulation capability information, if the regulation direction of the total regulation is increasing and the inverter's upper regulation capability is less than the regulation dead zone, then the inverter is uncontrollable; if the regulation direction of the total regulation is decreasing and the lower regulation capability is less than the regulation dead zone, then the inverter is not adjustable and does not undertake the regulation.

[0064] Step S105: Control commands are generated and issued. The adjustment amount and adjustment command type of each inverter are used to generate the control strategy of the inverter, which is then converted into specific active or reactive power remote adjustment control commands for the inverter. The commands are then issued to the photovoltaic inverter through the communication network to achieve closed-loop control of its output.

[0065] By real-time monitoring of transformer voltage and load rate in the distribution area, the system analyzes the operating region where voltage and load rate are located. If the operating region is in an over-limit area, a local voltage absorption control strategy is calculated at the distribution area level. If the operating region is in a normal area, the system monitors the coordination control commands with the upper-level distribution automation voltage absorption system in real time. If the commands exist and are valid, the system parses the upper-level coordination control commands and calculates the coordination strategy using the distribution transformer voltage limit and load rate limit as constraints, thus completing the coordination control with the upper-level voltage absorption system. The above control strategy calculates the total active power demand adjustment or total reactive power demand adjustment in the distribution area. Based on the operating status and adjustment capacity information of each photovoltaic inverter in the distribution area, the system searches for adjustable inverters and performs coordinated control of multiple photovoltaic inverters according to the set allocation rules. The demand adjustment is allocated to each adjustable inverter, and control commands corresponding to active power or reactive power are issued to the inverters to achieve closed-loop control. By implementing voltage absorption coordination control in the distribution area, it is ensured that the voltage and load rate of the distribution area connected to distributed photovoltaic power are kept within the qualified range. At the same time, coordination control with the superior is completed to achieve maximum absorption of distributed photovoltaic power.

[0066] Please see Figure 3 This paper presents a structural block diagram of an embodiment of a voltage absorption coordination control device for a distributed photovoltaic (PV) grid access area, which is applied to a distribution network voltage absorption coordination control system; it includes the following modules:

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

[0068] The transformer area-level local voltage absorption control module 302 is used for voltage absorption control in the over-limit operation area of ​​the transformer area. It performs real-time analysis on the over-limit operation area and calculates the total active power demand adjustment or total reactive power demand adjustment based on the adjustment strategy of different operation areas.

[0069] The upper-level voltage absorption coordination control module 303 is used for coordination control with the upper-level voltage absorption system. For the normal operation area, it detects the validity of the upper-level coordination command, parses the upper-level coordination command, and calculates the coordination strategy with the voltage limit of the transformer area and the load rate limit as constraints to obtain the total active power demand adjustment or the total reactive power demand adjustment.

[0070] The multi-photovoltaic inverter coordination control module 304 is used to allocate the total demand adjustment amount. Based on the operating status and adjustment capability information of the photovoltaic inverters, it finds the adjustable inverters and allocates the demand adjustment amount to each adjustable inverter according to the set allocation rules.

[0071] The control command generation and distribution module 305 is used to generate and execute control commands. Based on the inverter's adjustment amount and adjustment command type, it formulates the inverter's adjustment control strategy, converts the generated control strategy into specific control commands, and distributes the commands to the photovoltaic inverter through the communication network to achieve closed-loop control of its output.

[0072] The device collects real-time data from the distribution area through the "Operation Area Analysis Module" to divide the voltage absorption operation area. When in an out-of-limit area, the "Local Control Module" calculates the adjustment amount based on a preset strategy. If within the operating area, the "Upper-Level Coordination Module" verifies and executes the upper-level command. The "Inverter Allocation Module" selects adjustable inverters and assigns adjustment tasks. Finally, the "Command Execution Module" converts the control strategy into commands, realizing closed-loop control of the inverter output, thereby dynamically adjusting the distribution area voltage and load rate. By integrating local autonomous adjustment with upper-level command coordination, combined with the inverter's precise allocation mechanism, the device solves the problem of coordinated dynamic control of voltage fluctuations and voltage absorption in distributed photovoltaic distribution areas, improving voltage stability and absorption rate.

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

[0074] The "Operation Information Monitoring Standard Module" standardizes the operation data format of the system, distribution transformers, and inverters, ensuring accurate information exchange. The "Upper-Level Coordination Module" submodule verifies upper-level commands through both timeliness and correctness, avoiding interference from invalid commands. The "Inverter Allocation Module" submodule judges inverter controllability based on operating status and regulation capacity conditions, ensuring accurate issuance of regulation tasks. It also introduces multi-dimensional data standardization and command verification mechanisms, refining inverter controllability evaluation criteria to solve problems such as data chaos, erroneous command execution, and ineffective equipment regulation in traditional control, thus improving system reliability and regulation accuracy.

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

[0076] The abnormal data marking unit 502 is used to automatically identify abnormal operating data such as voltage exceeding the limit, load rate exceeding the limit, and inverter fault, and add markings to facilitate maintenance personnel to quickly locate abnormal periods.

[0077] The data analysis and processing unit 503, based on stored historical data, uses data mining algorithms to analyze voltage and load rate fluctuation patterns and inverter regulation efficiency, providing a basis for decision-making to optimize regulation strategies and equipment configuration.

[0078] Data interface unit 504 supports data interaction with external databases or data analysis platforms to achieve data sharing and remote access;

[0079] The "Data Storage and Analysis Module" continuously records the operating data of the transformer area and equipment; the "Anomaly Marking Unit" monitors and marks abnormal events in real time; the "Analysis and Processing Unit" analyzes voltage and load rate fluctuation patterns and equipment efficiency through data mining algorithms; and the "Data Interface Unit" supports data sharing, providing data support for regulation strategy optimization and equipment maintenance, realizing a closed-loop process from historical data to decision-making. By deeply integrating data storage and analysis functions into the voltage control process, and achieving "data-driven" strategy optimization through historical data mining, this approach differs from traditional experience-based control methods, providing 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, the specific structure and functions of which are as follows: an information display interface unit 601, which graphically displays the operating area of ​​the transformer voltage absorption, real-time parameters of the transformer and inverter, and the status information of the adjustment command execution in real time, and supports multiple visualization forms such as curves, charts and maps.

[0081] The operation control unit 602 provides a manual intervention interface, through which maintenance personnel can manually issue adjustment commands, modify control parameters, or switch control modes.

[0082] The alarm notification unit 603, when detecting voltage exceeding the limit, load rate exceeding the limit, equipment failure, or abnormal command execution, issues an alarm via voice and pop-up window, and displays detailed alarm information and handling suggestions.

[0083] The access control unit 604 sets hierarchical operation permissions for different users to ensure the security and standardization of system operations and prevent accidental operations from affecting system operation;

[0084] The "Human-Machine Interaction and Visualization Module" displays the system status in real time through a graphical interface, allowing maintenance personnel to manually intervene through the "Operation Control Unit." The "Alarm Notification Unit" provides immediate warnings and handling suggestions for abnormal events, while the "Access Control Unit" ensures operational security through hierarchical access control. These units work collaboratively to achieve efficient human-machine interaction and intelligent operation and maintenance. This constructs an integrated interactive system encompassing visual monitoring, manual intervention, intelligent alarms, and access management, breaking away from the traditional "black box" mode of control devices, significantly improving operational efficiency, reducing the risk of human error, and enhancing system security and usability.

[0085] In this invention, by real-time monitoring of the distribution transformer voltage and load rate, the operating region of the voltage and load rate is analyzed. If the operating region is in an over-limit area, a local voltage absorption control strategy is calculated at the distribution transformer level. If the operating region is in a normal area, the coordination control command with the upper-level distribution automation voltage absorption system is detected in real time. If the command exists and is valid, the upper-level coordination control command is parsed, and a coordination strategy is calculated using the distribution transformer voltage limit and load rate limit as constraints to complete the coordination control with the upper-level voltage absorption system. The above control strategy calculates the total active power demand adjustment or total reactive power demand adjustment of the distribution transformer area. Based on the operating status and adjustment capacity information of each photovoltaic inverter in the distribution transformer area, adjustable inverters are searched. According to the set allocation rules, coordinated control of multiple photovoltaic inverters is performed, and the demand adjustment is allocated to each adjustable inverter. Control commands corresponding to active power or reactive power are issued to the inverters to achieve closed-loop control. By implementing voltage absorption coordination control in the distribution area, it is ensured that the voltage and load rate of the distribution area connected to distributed photovoltaic power are kept within the qualified range. At the same time, coordination control with the superior is completed to achieve maximum absorption of distributed photovoltaic power.

[0086] By pioneering a hierarchical collaborative control architecture, dynamic and precise voltage regulation is achieved. The core control architecture adopts a hierarchical collaborative mechanism, breaking through the limitations of traditional single regulation modes. The "Transformer Area Voltage Absorption Operation Zone Analysis Module" divides the operation zone in real time, combining the autonomous over-limit regulation of the "Transformer Area-Level Local Voltage Absorption Control Module" with the command coordination of the "Upper-Level Voltage Absorption Coordination Control Module" to achieve differentiated responses under different operating conditions. Simultaneously, the "Multi-Inverter Coordination Control Module" precisely allocates regulation tasks based on inverter status, forming a closed-loop control in conjunction with the "Control Command Generation and Issuance Module." This architecture not only solves the voltage and load factor over-limit problems caused by distributed photovoltaic access but also significantly improves the system's adaptability to complex operating conditions, increasing voltage qualification rate while achieving maximum absorption, providing an innovative and systematic solution for transformer area voltage stability and absorption. Innovations are made in both data standardization and in-depth analysis. The "Operation Information Monitoring Standard Module" unifies the interaction data standards between the system, distribution transformers, and inverters, standardizing the transmission format of over 30 key information items, including system commissioning status, real-time distribution transformer parameters, and inverter target values. This completely solves the problem of chaotic data interaction in traditional control, improving 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 operational data, it uses machine learning algorithms to analyze the correlation between voltage fluctuations and inverter regulation, optimizing regulation strategies and providing a scientific quantitative basis for long-term system optimization, achieving a fundamental shift from experience-driven to data-driven approaches. A dual guarantee mechanism is proposed at the command execution and equipment management levels. The "Upper-Level Voltage Absorption Coordination Control Module" uses a "Timeliness Judgment Submodule" (setting commands to be valid within 10 minutes) and a "Correctness Judgment Submodule" (comparing commands with the actual regulation capacity of the distribution area) to avoid control failures caused by expired commands or execution beyond capacity, improving the effective execution rate of commands. The "Multi-Inverter Coordination Control Module" comprehensively evaluates inverter controllability through six indicators: equipment operating status, lockout status, and regulation dead zone. This ensures that regulation tasks are only assigned to devices that meet the conditions, eliminating ineffective regulation and reducing equipment malfunction rate. This mechanism significantly enhances the reliability of system coordination with higher-level commands and local device control, improving overall operational stability. The constructed "Human-Machine Interaction and Visualization Module" completely changes the traditional operation of control devices. The information display interface unit uses graphical and dynamic curve visualization technology to intuitively present voltage absorption operating areas and equipment operating information, improving the decision-making efficiency of maintenance personnel. The operation control unit supports manual intervention and parameter modification, and, in conjunction with the hierarchical permission settings of the permission management unit (e.g., divided into administrator, operator, and viewer levels), provides flexible control capabilities while ensuring system security. The alarm notification unit integrates voice alarms; when voltage exceeding limits, load exceeding limits, or inverter malfunctions are detected, an alarm can be issued within 3 seconds, providing a handling solution and shortening fault response time.This module achieves a deep integration of "automatic control + intelligent operation and maintenance," providing a demonstrative solution for the intelligent upgrading of the power grid. Therefore, through multi-module collaborative innovation, it achieves systematic breakthroughs in architecture design, data management, command execution, and operation and maintenance models, effectively solving the voltage absorption coordination and control problem in distributed photovoltaic grid connection areas, and possesses significant technological advancement and engineering application value.

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

Claims

1. A method for coordinated control of voltage absorption in distributed photovoltaic (PV) grid access areas, characterized in that, Applied to a distribution network substation-level voltage absorption coordination control system; the method includes: Analysis of voltage absorption operation area in transformer substations: including real-time monitoring and calculation of transformer substations and analysis of voltage absorption operation area; Local voltage absorption control at the transformer substation level: Real-time analysis is performed on over-limit operating areas, and the total active power demand adjustment or total reactive power demand adjustment is calculated based on the adjustment strategy of different operating areas. Upper-level voltage absorption coordination control: For the normal operating area, detect the effectiveness of the upper-level coordination command, analyze the upper-level coordination command, and calculate the coordination strategy with the voltage limit of the transformer area and the load rate limit as constraints to obtain the total active power demand adjustment or the total reactive power demand adjustment. Multi-PV inverter coordinated control: Based on the operating status and regulation capacity information of the PV inverters, the adjustable inverters are located, and the required regulation is distributed to each adjustable inverter according to the set allocation rules. Control command generation and issuance: Based on the inverter's adjustment amount and adjustment command type, an inverter adjustment control strategy is formulated. The generated control strategy is converted into specific control commands, which are then issued to the photovoltaic inverter through the communication network to achieve closed-loop control of its output. The upper-level voltage absorption coordination control includes: the current distribution transformer voltage absorption is within the normal operating range; parsing the upper-level command; detecting the validity of the upper-level command; when the upper-level command is valid, calculating the upper-level voltage absorption coordination control strategy based on the transformer area voltage limit and load rate limit; calculating the total active or reactive power demand of the transformer area; the validity judgment of the coordination command mainly includes timeliness and correctness. Timeliness judgment involves obtaining the coordination command at the specified time and determining if the time has expired. If so, the command is invalid; otherwise, the timeliness requirement is met. Correctness judgment involves parsing the coordination command; if the coordination command... If the value of the command exceeds the actual regulation capacity of the distribution area, the command is deemed invalid. If the value of the command exceeds the regulation dead zone of the distribution area, the command is deemed invalid. Multi-PV inverter coordinated control uses inverter operating status, regulation capacity information, regulation step size, and regulation dead zone control information to locate adjustable inverters and allocate total active or reactive power regulation. Multiple allocation methods are provided: installed capacity ratio, theoretical output ratio, sharing factor ratio, manual priority ranking, and utilization hours ranking. Based on the set allocation method, the total active or reactive power regulation is calculated and allocated to each adjustable inverter to obtain the regulation amount of each inverter. Based on the operating status and lockout status of the photovoltaic inverter, search for inverters whose operating status is "on" and whose lockout status is "unlocked". Based on the photovoltaic inverter's regulation capacity information, if the regulation direction of the total regulation is increasing and the inverter's upper regulation capacity is less than the regulation dead zone, then the inverter is uncontrollable. If the regulation direction of the total regulation is decreasing and the lower regulation capacity is less than the regulation dead zone, then the inverter cannot be adjusted and does not bear the regulation amount. Control commands are generated and issued, and the adjustment quantities and adjustment command types of each inverter are used to generate the inverter's control strategy, which is then transformed into specific active or reactive power remote adjustment control commands for the inverter. These commands are then sent to the photovoltaic inverters through the communication network to achieve closed-loop control of their output.

2. The voltage absorption coordination control method for distributed photovoltaic grid access areas according to claim 1, characterized in that, The analysis of voltage absorption operation areas in transformer substations includes real-time monitoring and calculation of the substation area, specifically: real-time data monitoring of the substation area, real-time calculation of transformer load rate, and monitoring of the operation of the system, transformers, and photovoltaic inverters. Real-time data for the transformer area: 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 factor: The real-time load factor is calculated by dividing the real-time current by the maximum allowable current. Voltage pass rate: The voltage pass rate from zero point to the current time is calculated in real time based on the voltage limit range and voltage acquisition data. System operation information: commissioning status, interlocking status, open loop, closed loop control mode; Distribution transformer operating information: open-loop and closed-loop control modes, upper voltage limit, and lower voltage limit; Inverter operating information: remote status, operating status, lockout 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 grid access areas according to claim 1, characterized in that, Voltage absorption operation area analysis includes: comparing the real-time monitored voltage and load rate with preset limits, and determining the operating area of ​​the transformer substation based on the range of voltage and load rate. The operating area refers to dividing the voltage-load rate plane diagram of the transformer substation's upper and lower voltage limits and upper and lower load rate limits into nine areas, in the following order: 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 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, and voltage below the lower limit and load rate below the lower limit.

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

5. A voltage absorption coordination and control device for distributed photovoltaic grid access areas, characterized in that, include: The transformer area voltage absorption operation area analysis module (301) is used for real-time monitoring and calculation of the transformer area and analysis of the voltage absorption operation area to obtain the current operating area of ​​the transformer area voltage absorption. The transformer area-level local voltage absorption control module (302) is used for voltage absorption control in the over-limit operation area of ​​the transformer area. It performs real-time analysis on the over-limit operation area and calculates the total active power demand adjustment or total reactive power demand adjustment based on the adjustment strategy of different operation areas. The upper-level voltage absorption coordination control module (303) is used for coordination control with the upper-level voltage absorption system. For the normal operation area, it detects the validity of the upper-level coordination command, parses the upper-level coordination command, and calculates the coordination strategy with the voltage limit of the transformer area and the load rate limit as constraints to obtain the total active power demand adjustment or the total reactive power demand adjustment. The multi-photovoltaic inverter coordination control module (304) is used to allocate the total demand adjustment amount. Based on the operating status and adjustment capability information of the photovoltaic inverters, it finds the adjustable inverters and allocates the demand adjustment amount to each adjustable inverter according to the set allocation rules. The control command generation and distribution module (305) is used to generate and execute control commands. Based on the inverter's adjustment amount and adjustment command type, it formulates the inverter's adjustment control strategy, converts the generated control strategy into specific control commands, and distributes the commands to the photovoltaic inverter through the communication network to achieve closed-loop control of its output. It also includes an operation information monitoring specification module (4), which is used to standardize the monitoring information of the transformer area and the interaction information between the transformer area and the inverter, covering the system, transformer and inverter operation status parameters. The upper voltage absorption coordination control module (303) includes an instruction validity determination unit, which judges the timeliness of the coordination instruction through the first judgment submodule and the correctness of the instruction through the second judgment submodule to ensure the instruction is effective. The multi-photovoltaic inverter coordination control module (304) includes a controllability evaluation unit, which judges whether the inverter undertakes the regulation requirement by comprehensively considering the inverter operation status and regulation capability conditions through the controllability determination submodule, the first judgment submodule and the second judgment submodule.

6. The voltage absorption coordination control device for distributed photovoltaic grid access areas according to claim 5, characterized in that: The device also includes a data storage and analysis module (5), including: a historical data storage unit (501), used to store historical data of information on real-time monitoring and calculation of the distribution area, upper-level 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; The abnormal data marking unit (502) is used to automatically identify abnormal operating data such as voltage over-limit, load rate over-limit, and inverter fault, and add markings to facilitate maintenance personnel to quickly locate abnormal periods. The data analysis and processing unit (503) analyzes voltage fluctuation patterns, load rate fluctuation patterns, and inverter regulation efficiency based on stored historical data and data mining algorithms, providing a basis for decision-making to optimize regulation strategies and equipment configuration. The data interface unit (504) supports data interaction with external databases or data analysis platforms to achieve data sharing and remote access.

7. The voltage absorption coordination control device for distributed photovoltaic grid access areas according to claim 5, 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 distribution area, the real-time parameters of the distribution transformer and inverter, and the status information of the adjustment command execution in a graphical manner in real time, and supports multiple visualization forms such as curves, charts and maps; The operation control unit (602) provides a manual intervention interface, through which maintenance personnel can manually issue adjustment commands, modify control parameters, or switch control modes. The alarm notification unit (603) issues an alarm via voice or pop-up window when it detects voltage exceeding the limit, load rate exceeding the limit, equipment failure, or abnormal command execution, and displays detailed alarm information and handling suggestions. The access control unit (604) sets hierarchical operation permissions for different users to ensure the security and standardization of system operations and prevent accidental operation from affecting system operation.

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