Power control method for low-voltage flexible distribution network power supply system

Abstract

The invention relates to the technical field of power distribution and power supply, in particular to a power control method for a low-voltage flexible distribution network power supply system, which comprises the steps of system monitoring and data acquisition, data processing, operation mode identification, execution of different control steps according to a control mode, fault detection and processing and coordinated control and optimization. The intelligent level and the operation efficiency of the low-voltage flexible distribution network power supply system are remarkably improved through the steps of integrated system monitoring, data processing, operation mode recognition, fault detection and processing, coordination control and optimization and the like, the system state can be sensed in real time, different incoming line operation modes can be accurately recognized, and the operation efficiency of the low-voltage flexible distribution network power supply system is improved. And the output power and the voltage are automatically adjusted according to the actual operation condition, stable and efficient operation of the system is ensured, meanwhile, the reliability and the safety of the system are further enhanced by a rapid fault detection and targeted processing mechanism, and the power supply quality and the user experience are integrally improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution and supply in the smart grid industry, and in particular to a power control method for a low-voltage flexible distribution network power supply system. BACKGROUND

[0002] With the rapid development of global economy and industry, as a core element and important resource supporting national development, electric power energy is facing major changes. The drawbacks of traditional power grids are gradually highlighted, especially in coping with the rapid expansion of renewable energy distributed grid connection, industrial scale, and the increase of DC load, etc. Therefore, the development of new, efficient and intelligent power distribution systems has become an important trend in the power industry.

[0003] As an important part of modern power systems, low-voltage flexible distribution network power supply systems bear the heavy responsibility of stably and efficiently delivering electric energy to users. However, with the continuous expansion of the power grid and the access of distributed energy (such as solar and wind energy), traditional power supply systems face many challenges: large load fluctuations: the output of distributed energy has intermittency and instability, leading to frequent fluctuations in grid load, increasing the difficulty of system regulation, increased system complexity: with the complication of power grid structure, the switching and coordination between different incoming line operation modes become more complex, and higher requirements are put forward for the intelligent level of the system, fault detection and processing lag: traditional power supply systems often have a lag in fault detection and processing, making it difficult to respond quickly and restore power supply, affecting user experience and power supply reliability. SUMMARY

[0004] In order to overcome the above problems, the present application provides a power control method for a low-voltage flexible distribution network power supply system.

[0005] The technical solution of the present application is: a power control method for a low-voltage flexible distribution network power supply system, comprising the following steps:

[0006] S11: system monitoring and data acquisition, installing sensors and monitoring equipment in the low-voltage flexible distribution network power supply system, and using the installed sensors and monitoring equipment to collect key parameters of each part of the low-voltage flexible distribution network power supply system in real time, wherein the key parameters include voltage, current and power;

[0007] S12: data processing, processing and analyzing the data collected by the sensors and monitoring equipment to understand the current operating state and load condition of the low-voltage flexible distribution network power supply system;

[0008] S13: Mode recognition, according to the results of data processing and analysis, the actual operation state of the low-voltage flexible distribution network power supply system is identified, wherein the operation state of the low-voltage flexible distribution network power supply system includes single-line incoming line operation mode, double-line incoming line operation mode, three-line incoming line operation mode and four-line incoming line operation mode;

[0009] S14: According to the actual operation state of the low-voltage flexible distribution network power supply system, the control mode of the low-voltage flexible distribution network power supply system is divided into single-line incoming line operation mode control and multi-line incoming line operation mode control, and different control steps are executed according to the two control modes;

[0010] S15: Fault detection and processing, by processing and analyzing the data collected by sensors and monitoring devices, identifying the fault points in the low-voltage flexible distribution network power supply system, and taking targeted measures according to the location and cause of the fault points;

[0011] S16: Coordinated control and optimization, set up a coordinated control unit, wherein the coordinated control unit is used to detect the operation state and load condition of the low-voltage flexible distribution network power supply system, and automatically adjust the output power and voltage level of each part according to the preset control strategy and algorithm.

[0012] As preferred, when installing sensors and monitoring devices in the low-voltage flexible distribution network power supply system, the installed sensors and monitoring devices include voltage sensors, current sensors, liquid level sensors, smart meters, power quality monitoring devices and intelligent terminals, voltage sensors are used to measure the voltage value in the power system and convert it into measurable and transmissible signals, current sensors are used to measure the current value in the circuit and transform the large current signal into a small current signal through the principle of electrical electromagnetic induction, liquid level sensors are used to collect the liquid level in the oil pump, oil tank, battery and water tank, smart meters are used to store and process a large amount of power data by using digital signal processing technology, and transmit the power data to the host computer through communication means, power quality monitoring devices are used to monitor and analyze the power quality in the low-voltage flexible distribution network power supply system in real time, and intelligent terminals are used to convert the running state of power equipment collected by sensors into electrical signals and process and transmit them.

[0013] As preferred, when processing and analyzing the data collected by sensors and monitoring devices to understand the current operation state and load condition of the low-voltage flexible distribution network power supply system, the following steps are included:

[0014] S21: Data cleaning, including removing duplicate data, processing missing values, correcting erroneous data and standardizing data format and unit;

[0015] S22: Data conversion, including data type conversion, data encoding and data normalization;

[0016] S23: Data aggregation, including aggregating data by dimensions and calculating statistics, wherein the selected dimensions include time, location, and category when aggregating data by dimensions, and the calculated statistics include mean, median, and standard deviation when calculating statistics;

[0017] S24: Data analysis and visualization, applying statistical methods and machine learning algorithms to identify patterns, trends, and outliers in the data, and presenting the analysis results in the form of charts and graphs.

[0018] As a preferred, when processing missing values, the principle formula used is:

[0019]

[0020] where y is the estimated value of the missing value, (x1, y1) and (x2, y2) are the coordinates of the two adjacent points of the missing value in the coordinate system, and x is the horizontal coordinate of the missing value.

[0021] As a preferred, when identifying the actual operating state of the low-voltage flexible distribution network power supply system according to the results of data processing and analysis, the actual operating state of the low-voltage flexible distribution network power supply system is identified according to the following rules:

[0022] A11: Analyze the voltage and current of each incoming line, whether it is within a certain set range, if the voltage and current of a certain incoming line are lower than the set threshold, it indicates that the incoming line is not in operation;

[0023] A12: Analyze the power provided by each incoming line to the system, if the power contribution of a certain incoming line is lower than the threshold, it indicates that the incoming line is not in operation;

[0024] A13: If only the voltage, current and power data of one incoming line are normal, and the data of other incoming lines are lower than the threshold, it is judged that the low-voltage flexible distribution network power supply system is currently in single incoming line operation mode.

[0025] As a preferred, in the control mode of single incoming line operation mode control, the control steps executed are:

[0026] S31: Energy storage charging control, according to the state of the energy storage system and the system demand, control the energy storage device to charge or discharge, to ensure that the energy storage device can provide enough energy support when needed;

[0027] S32: Emergency power support control, when it is monitored that a certain incoming line has power shortage or failure, through the control of the flexible HVDC converter, the power of the energy storage system and the distributed photovoltaic system is quickly transferred to the power shortage line, to realize emergency power support;

[0028] S33: Reactive power control of the flexible HVDC converter, adjusting the reactive power output of the flexible HVDC converter to improve the reactive power balance of the low-voltage flexible distribution network power supply system and improve the voltage stability and power factor of the low-voltage flexible distribution network power supply system.

[0029] As preferred, in the control mode of the multi-feeder operation mode control, the control steps executed are:

[0030] S41: Zone power support control, according to the power load conditions of each feeder, performing zone power support control, transferring power from the feeder with lighter load to the feeder with heavier load through control of the flexible HVDC converter, to achieve balanced distribution of power;

[0031] S42: Emergency power support control, when a serious fault or power shortage is detected on a feeder, emergency power support is achieved through control of the flexible HVDC converter;

[0032] S43: Reactive power control of the flexible HVDC converter, adjusting the reactive power output of the flexible HVDC converter to maintain the reactive power balance and voltage stability of the system.

[0033] As preferred, in the process of identifying fault points in the low-voltage flexible distribution network power supply system through processing and analysis of data collected by sensors and monitoring devices, and taking targeted treatment measures according to the location and cause of the fault points, the following steps are included:

[0034] S51: Fault monitoring, using intelligent sensing technology and big data analysis technology to analyze the data collected by sensors and monitoring devices to timely detect fault points in the power grid;

[0035] S52: Fault judgment, according to the monitored data, combining with the preset fault judgment logic, judging the type, location and influence range of the fault;

[0036] S53: Isolation operation, after determining the fault point, isolating the fault area from the low-voltage flexible distribution network power supply system through control of the control devices in the low-voltage flexible distribution network power supply system to prevent the spread of the fault;

[0037] S54: Start island operation mode, realize load-bearing island operation through the flexible HVDC converter to ensure the continuity of power supply in the non-fault area;

[0038] S55: Adjust the control strategy of the flexible HVDC converter to maintain stable voltage and frequency and ensure power supply quality;

[0039] S56: Source-load balance control, by collecting the electrical quantities of the entire microgrid in real time, judging whether the system is source-load balanced, if the source-load is unbalanced, then restoring the balance by adjusting the charge-discharge strategy of the energy storage system and switching the load;

[0040] S57: After the fault is repaired, re-evaluate and decide whether to resume grid-connected operation, if it is decided to be grid-connected, gradually synchronize the island system with the main grid by adjusting the control strategy of the flexible HVDC converter, and finally realize grid connection.

[0041] As preferred, after processing and analyzing the data collected by sensors and monitoring devices to understand the current operating state and load condition of the low-voltage flexible distribution network power supply system, the following steps are included:

[0042] S61: According to the system design and equipment specifications, determine the rated load value of each line, and determine the overload protection trigger threshold value of each line according to the rated load value;

[0043] S62: Real-time calculation of the actual load value of each line;

[0044] S63: When the actual load value of the line reaches the overload protection trigger threshold value, trigger the overload protection operation, and according to the importance of the line, adopt one of the two overload protection operations of circuit interruption and power limitation to protect the line.

[0045] As preferred, when setting the coordinated control unit and automatically adjusting the output power and voltage level of each part according to the preset control strategy and algorithm, the following steps are included:

[0046] S71: Process and analyze the collected data to monitor the operating state and load condition of the low-voltage flexible distribution network power supply system in real time;

[0047] S72: Identify abnormal states and potential risks of the low-voltage flexible distribution network power supply system, wherein the abnormal states and potential risks of the low-voltage flexible distribution network power supply system include overload, short circuit and voltage fluctuation;

[0048] S73: According to the real-time monitored state of the low-voltage flexible distribution network power supply system and the preset control strategy library, match the corresponding control strategy;

[0049] S74: According to the matched control strategy, automatically adjust the output power and voltage level of each part of the low-voltage flexible distribution network power supply system;

[0050] S75: The adjusted system state is monitored and verified again to ensure that the adjustment effect meets the expectation.

[0051] The beneficial effects of the present application are:

[0052] 1. By integrating system monitoring, data processing, operation mode identification, fault detection and handling, and coordinated control and optimization, the intelligent level and operation efficiency of the low-voltage flexible distribution network power supply system are significantly improved. This scheme can real-time perceive system state, accurately identify different incoming line operation modes, and automatically adjust output power and voltage according to actual operation conditions to ensure stable and efficient operation of the system. At the same time, the rapid detection and targeted handling mechanism of faults further enhances the reliability and safety of the system, and improves the power supply quality and user experience as a whole;

[0053] 2. By implementing three steps of partition power support control, emergency power support control, and flexible rectifier reactive power control, the stability and flexibility of the power grid are significantly improved under multi-line incoming mode. Partition power support control realizes automatic balanced distribution of power, effectively avoiding the situation that some incoming lines are overloaded while others are idle, and improves the overall operation efficiency. Emergency power support control can quickly respond to sudden faults or power shortages in incoming lines, and provide immediate power support through flexible rectifiers to prevent fault expansion and ensure grid safety. In addition, the precise adjustment of flexible rectifier reactive power control ensures the reactive power balance and voltage stability of the system, further enhancing the reliability and power quality of the grid. In summary, this technical solution significantly enhances the fault response capability, operation efficiency and stability of the grid, providing a strong guarantee for safe and stable operation in complex grid environments;

[0054] 3. Under single-line incoming mode, the low-voltage flexible distribution network power supply system is effectively improved in flexibility and stability by implementing steps such as energy storage charging control, emergency power support control, and flexible rectifier reactive power control. Energy storage charging control ensures that energy storage devices can provide sufficient energy support at critical moments, enhancing the system's backup capacity and reliability. Emergency power support control can quickly respond to incoming line faults or power shortages by transferring standby power to the power-starved line through flexible rectifiers to ensure power continuity. In addition, the introduction of flexible rectifier reactive power control further optimizes the reactive power balance of the system, improves voltage stability and power factor, and overall improves the system's operation efficiency and power quality. BRIEF DESCRIPTION OF DRAWINGS

[0055] Fig. 1 The working flowchart of the power control method for the low-voltage flexible distribution network power supply system of the present application is shown.

[0056] Fig. 2 The control step diagram under single-line incoming mode in the power control method for the low-voltage flexible distribution network power supply system of the present application is shown. DETAILED DESCRIPTION

[0057] The present application will be further described in conjunction with the drawings and examples.

[0058] Please see Figs. 1-2 For power supply systems such as 750 kV and above AC transmission, large-scale power grid security and defense systems, and intelligent dispatching systems, this invention provides an embodiment: a power control method for low-voltage flexible distribution network power supply systems, comprising the following steps:

[0059] S11: System monitoring and data acquisition. Sensors and monitoring equipment are installed in the low-voltage flexible distribution network power supply system. The installed sensors and monitoring equipment are used to collect key parameters of each part of the low-voltage flexible distribution network power supply system in real time. The key parameters include voltage, current and power.

[0060] S12: Data processing, which involves processing and analyzing data collected using sensors and monitoring equipment to understand the current operating status and load conditions of the low-voltage flexible distribution network power supply system;

[0061] S13: Operation mode identification. Based on the results of data processing and analysis, the actual operation status of the low-voltage flexible distribution network power supply system is identified. The operation status of the low-voltage flexible distribution network power supply system includes single-incoming line operation mode, dual-incoming line operation mode, three-incoming line operation mode and four-incoming line operation mode.

[0062] S14: Based on the actual operating status of the low-voltage flexible distribution network power supply system, the control mode of the low-voltage flexible distribution network power supply system is divided into two control modes: single-incoming-line operation mode control and multi-incoming-line operation mode control. Different control steps are executed according to the two control modes.

[0063] S15: Fault detection and handling. By processing and analyzing the data collected by sensors and monitoring equipment, fault points in the low-voltage flexible distribution network power supply system are identified, and targeted handling measures are taken according to the location and cause of the fault.

[0064] S16: Coordination Control and Optimization. A coordination control unit is set up. The coordination control unit is used to detect the operating status and load of the low-voltage flexible distribution network power supply system, and automatically adjust the output power and voltage level of each part according to the preset control strategy and algorithm.

[0065] Specifically, as described above, this invention significantly improves the intelligence level and operational efficiency of low-voltage flexible distribution network power supply systems by integrating system monitoring, data processing, operation mode identification, fault detection and handling, and coordinated control and optimization. This solution can perceive the system status in real time, accurately identify different incoming line operation modes, and automatically adjust the output power and voltage according to the actual operating conditions to ensure stable and efficient system operation. At the same time, the rapid fault detection and targeted handling mechanism further enhances the reliability and security of the system, and improves the overall power supply quality and user experience.

[0066] Preferably, when installing sensors and monitoring equipment in a low-voltage flexible distribution network power supply system, the installed sensors and monitoring equipment include voltage sensors, current sensors, liquid level sensors, smart meters, power quality monitoring equipment, and smart terminals. Voltage sensors are used to measure the voltage value in the power system and convert it into a measurable and transmittable signal. Current sensors are used to measure the current value in the circuit and convert large current signals into small current signals through the principle of electromagnetic induction. Liquid level sensors are used to collect the liquid level height in oil pumps, oil tanks, batteries, and water tank containers. Smart meters are used to store and process large amounts of electrical energy data using digital signal processing technology and transmit the electrical energy data to a host computer through communication means. Power quality monitoring equipment is used to monitor and analyze the power quality in the low-voltage flexible distribution network power supply system in real time. Smart terminals are used to convert the operating status of the power equipment collected by the sensors into electrical signals, and process and transmit them.

[0067] Specifically, as described above, this invention installs a comprehensive suite of sensors and monitoring equipment, including voltage sensors, current sensors, liquid level sensors, smart meters, power quality monitoring equipment, and smart terminals, in a low-voltage flexible distribution network power supply system. This technical solution significantly enhances the system's monitoring capabilities and intelligence level. The accurate measurement by voltage and current sensors ensures real-time monitoring of power system parameters. The addition of liquid level sensors expands the monitoring range of system auxiliary equipment status. Smart meters and power quality monitoring equipment enable accurate metering and quality monitoring of power data. The integration of smart terminals further improves data processing efficiency and transmission reliability, providing a solid data foundation for stable system operation and rapid fault response. Overall, this enhances the safety, reliability, and operational efficiency of the power supply system.

[0068] Preferably, the processing and analysis of data collected using sensors and monitoring equipment to understand the current operating status and load conditions of the low-voltage flexible distribution network power supply system includes the following steps:

[0069] S21: Data cleaning, which includes removing duplicate data, handling missing values, correcting erroneous data, and standardizing data formats and units;

[0070] S22: data conversion, including data type conversion, data encoding and data normalization;

[0071] S23: data aggregation, including data summarization according to dimensions and calculation of statistical quantities, wherein the selected dimensions include time, location and category, and the calculated statistical quantities include mean, median and standard deviation;

[0072] S24: data analysis and visualization, applying statistical methods and machine learning algorithms to identify patterns, trends and outliers in the data, and presenting the analysis results in the form of charts and graphs.

[0073] Specifically, as described above, the technical solution of the above data processing and analysis effectively improves the accuracy and usability of the low-voltage flexible distribution network power supply system data through a series of refined steps, including data cleaning, conversion, aggregation, analysis and visualization. Data cleaning ensures data quality and lays a solid foundation for subsequent analysis; data conversion and normalization enhance data compatibility and comparability; data aggregation helps to understand system operation status and load conditions from multiple dimensions; finally, through data analysis and visualization, the patterns, trends and outliers in the data are intuitively presented, providing strong support for system monitoring, optimization and decision-making. This series of steps collectively improves the intelligent level of system management and enhances the stability and reliability of the system.

[0074] As a preferred, when processing the missing values, the principle formula used is:

[0075]

[0076] where y is the estimated value of the missing value, (x1, y1) and (x2, y2) are the coordinates of the two adjacent points of the missing value in the coordinate system, and x is the horizontal coordinate of the missing value.

[0077] Specifically, as described above, when processing missing values in low-voltage flexible distribution network power supply system data, the present application uses a principle formula based on coordinate interpolation to calculate the estimated value, which significantly improves the accuracy and integrity of data processing. By using the coordinate information of the two adjacent points of the missing value in the coordinate system, this formula can accurately estimate the missing value, effectively fill in the data gaps and reduce the analysis deviation caused by data missing. This method not only enhances the continuity and reliability of the data, but also provides a more solid data foundation for subsequent data analysis and system monitoring, further improving the intelligent management level of the system.

[0078] As preferred, when identifying the actual operation state of the low-voltage flexible distribution network power supply system according to the results of data processing and analysis, the actual operation state of the low-voltage flexible distribution network power supply system is identified according to the following rules:

[0079] A11: analyze the voltage and current of each incoming line, whether it is within a certain set range, if the voltage and current of a certain incoming line is lower than the set threshold, it indicates that the incoming line is not in operation state;

[0080] A12: analyze the power provided by each incoming line to the system, if the power contribution of a certain incoming line is lower than the threshold, it indicates that the incoming line is not running;

[0081] A13: if only one incoming line has normal voltage, current and power data, and the data of other incoming lines is lower than the threshold, it is judged that the low-voltage flexible distribution network power supply system is currently in single incoming line operation mode.

[0082] Specifically, as described above, the application accurately evaluates the actual operation state of the low-voltage flexible distribution network power supply system by formulating detailed identification rules. By monitoring the voltage, current and power contribution of each incoming line, this scheme can quickly identify abnormal or non-operating incoming lines, and further determine whether the system is in single incoming line operation mode. This fine operation state identification not only improves the reliability and stability of the system, but also provides timely and accurate information for maintenance personnel, facilitating their rapid response and taking appropriate maintenance measures, thereby ensuring the safe and efficient operation of the low-voltage flexible distribution network power supply system.

[0083] As preferred, in the control mode of single incoming line operation mode control, the control steps executed are:

[0084] S31: energy storage charging control, according to the state of the energy storage system and the system demand, control the energy storage device to charge or discharge, to ensure that the energy storage device can provide enough energy support when needed;

[0085] S32: emergency power support control, when it is monitored that a certain incoming line has power shortage or failure, the power of the energy storage system and the distributed photovoltaic system is quickly transferred to the power shortage line through the control of the flexible converter, to realize emergency power support;

[0086] S33: flexible converter reactive power control, adjust the reactive power output of the flexible converter to improve the reactive power balance of the low-voltage flexible distribution network power supply system, and improve the voltage stability and power factor of the low-voltage flexible distribution network power supply system.

[0087] Specifically, as described above, in the single-line incoming mode, the application effectively improves the flexibility and stability of the low-voltage flexible distribution network power supply system through the implementation of energy storage charging control, emergency power support control, and flexible converter reactive power control. The energy storage charging control ensures that the energy storage device can provide sufficient energy support at critical moments, enhancing the system's backup capacity and reliability. The emergency power support control quickly responds when there is a line fault or power shortage, and transfers standby power to the power-starved line through the flexible converter, ensuring power continuity. In addition, the introduction of flexible converter reactive power control further optimizes the system's reactive power balance, improves voltage stability and power factor, and overall improves system operation efficiency and power quality.

[0088] As a preferred embodiment, in the multi-line incoming mode control mode, the control steps executed are:

[0089] S41: Zone power support control, according to the power load of each incoming line, the zone power support control is carried out, and the power is transferred from the incoming line with lighter load to the incoming line with heavier load through the control of the flexible converter, realizing the balanced distribution of power;

[0090] S42: Emergency power support control, when a serious fault or power shortage is detected in a certain incoming line, emergency power support is realized through the control of the flexible converter;

[0091] S43: Flexible converter reactive power control, adjust the reactive power output of the flexible converter to maintain the reactive power balance and voltage stability of the system.

[0092] Specifically, as described above, the application significantly improves the stability and flexibility of the power grid in the multi-line incoming mode through the implementation of the three steps of zone power support control, emergency power support control, and flexible converter reactive power control. The zone power support control realizes the automatic balanced distribution of power, effectively avoiding the situation that some incoming lines are overloaded while others are idle, and improves the overall operation efficiency. The emergency power support control quickly responds when there is a sudden fault or power shortage in the incoming line, and provides immediate power support through the flexible converter to prevent the fault from expanding and ensure the safety of the power grid. In addition, the precise adjustment of the flexible converter reactive power control ensures the reactive power balance and voltage stability of the system, further enhancing the reliability and power quality of the power grid. In summary, this technical solution significantly enhances the fault response capability, operation efficiency, and stability of the power grid, providing a strong guarantee for the safe and stable operation of the power grid in complex environments.

[0093] As a preferred embodiment, when the data collected by the sensors and monitoring devices is processed and analyzed to identify the fault points in the low-voltage flexible distribution network power supply system, and targeted treatment measures are taken according to the location and cause of the fault points, the following steps are included:

[0094] S51: Fault monitoring, using intelligent sensing technology and big data analysis technology to analyze the data collected by sensors and monitoring devices to timely find fault points in the power grid;

[0095] S52: Fault judgment, according to the monitored data, combined with the preset fault judgment logic, to judge the type, location and influence range of the fault;

[0096] S53: Isolation operation, after determining the fault point, by controlling the control device in the low-voltage flexible distribution network power supply system, the fault area is isolated from the low-voltage flexible distribution network power supply system to prevent the spread of the fault;

[0097] S54: Start island operation mode, realize load island operation through the flexible converter, and ensure the continuity of power supply in the non-fault area;

[0098] S55: Adjust the control strategy of the flexible converter to maintain stable voltage and frequency and ensure power supply quality;

[0099] S56: Source-load balance control, by real-time acquisition of the electrical quantity of the whole micro-grid, to judge whether the system is source-load balanced, if the source-load is unbalanced, adjust the charge-discharge strategy of the energy storage system and switch the load to restore the balance;

[0100] S57: Fault repair, and after fault repair, re-evaluate and decide whether to restore grid-connected operation, if decided to grid-connected, adjust the control strategy of the flexible converter to make the island system gradually synchronized with the main grid, and finally realize grid-connected.

[0101] Specifically, as described above, the present application integrates sensor monitoring, intelligent data analysis, accurate fault judgment, rapid isolation and island operation strategy, effectively improves the fault response ability and power supply reliability of the low-voltage flexible distribution network power supply system, when a fault occurs, the fault point can be quickly identified and the fault area can be isolated to prevent the spread of the fault, at the same time, the island operation mode is started to ensure uninterrupted power supply in the non-fault area, by dynamically adjusting the control strategy of the flexible converter, the voltage and frequency are maintained stable, the power supply quality is guaranteed, in addition, the source-load balance control mechanism can respond to the system state in real time, restore the system balance through energy storage and load management, after fault repair, the system can intelligently evaluate and safely restore grid-connected, which improves the intelligentization, automation level and emergency response ability of the power grid

[0102] As a preferred, after processing and analyzing the data collected by sensors and monitoring devices to understand the current operation state and load condition of the low-voltage flexible distribution network power supply system, the following steps are further included:

[0103] S61: According to the system design and device specifications, determine the rated load value of each line, and determine the overload protection trigger threshold value of each line according to the rated load value;

[0104] S62: Real-time calculation of the actual load value of each line;

[0105] S63: When the actual load value of the line reaches the overload protection trigger threshold value, trigger the overload protection operation, and according to the importance of the line, adopt one of the two overload protection operations of cutting off the circuit and power limiting to protect the line.

[0106] Specifically, as described above, the present application provides a precise overload protection mechanism for low-voltage flexible distribution network power supply system through real-time data processing and intelligent analysis, combined with system design and device specifications. By setting the rated load and overload protection trigger threshold value of each line, real-time monitoring of the actual load is realized. Once the threshold value is reached, the system will intelligently select to cut off the circuit or implement power limitation according to the importance of the line, effectively preventing device damage and power grid failure caused by overload, ensuring the safety and stability of the power grid operation, and improving the intelligent management level of the power grid.

[0107] As a preferred, when setting the coordinated control unit and automatically adjusting the output power and voltage level of each part according to the preset control strategy and algorithm, the following steps are included:

[0108] S71: Process and analyze the collected data to monitor the running state and load condition of the low-voltage flexible distribution network power supply system in real time;

[0109] S72: Identify the abnormal state and potential risk of the low-voltage flexible distribution network power supply system, wherein the abnormal state and potential risk of the low-voltage flexible distribution network power supply system include overload, short circuit and voltage fluctuation;

[0110] S73: According to the state of the low-voltage flexible distribution network power supply system monitored in real time and the preset control strategy library, match the corresponding control strategy;

[0111] S74: According to the matched control strategy, automatically adjust the output power and voltage level of each part of the low-voltage flexible distribution network power supply system;

[0112] S75: The adjusted system state is monitored and verified again to ensure that the adjustment effect meets the expectation.

[0113] Specifically, as described above, the application realizes intelligent monitoring and automatic adjustment of the low-voltage flexible distribution network power supply system by introducing a coordination control unit, which can analyze system data in real time, accurately identify abnormal states and potential risks such as overload, short circuit and voltage fluctuation, and quickly match and execute corresponding adjustment measures according to the preset control strategy library. This automatic adjustment mechanism effectively improves the response speed and adjustment accuracy of the system to changes, ensures the stability and optimization of output power and voltage level, and further enhances the safety and reliability, operation efficiency and power supply quality of the power grid. At the same time, by continuously monitoring and verifying the adjustment effect, the accuracy and effectiveness of the control strategy are ensured, providing solid technical support for the stable operation of the low-voltage flexible distribution network power supply system.

[0114] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A power control method for a low voltage flexible distribution network power supply system; characterized by: Comprise the following steps: S11: system monitoring and data acquisition, install sensors and monitoring equipment in the low-voltage flexible distribution network power supply system, use the installed sensors and monitoring equipment to collect the key parameters of each part of the low-voltage flexible distribution network power supply system in real time, wherein the key parameters include voltage, current and power; S12: data processing, processing and analyzing the data collected by the sensor and monitoring device to understand the current operation state and load condition of the low-voltage flexible distribution network power supply system; S13: operation mode identification, according to the result of data processing and analysis, the actual operation state of the low-voltage flexible distribution network power supply system is identified, wherein the operation state of the low-voltage flexible distribution network power supply system includes single line operation mode, double line operation mode, three line operation mode and four line operation mode; S14: according to the actual operation state of the low-voltage flexible distribution network power supply system, the control mode of the low-voltage flexible distribution network power supply system is divided into single line operation mode control and multi line operation mode control, and different control steps are executed according to the two groups of control mode; S15: fault detection and processing, by processing and analyzing the data collected by the sensor and monitoring device, identifying the fault point in the low-voltage flexible distribution network power supply system, and taking targeted processing measures according to the position and fault reason of the fault point; S16: coordination control and optimization, set up coordination control unit, wherein the coordination control unit is used to detect the operation state and load condition of the low-voltage flexible distribution network power supply system, and automatically adjust the output power and voltage level of each part according to the preset control strategy and algorithm.

2. The power control method for low voltage flexible distribution network power supply system according to claim 1, characterized in that: When installing sensors and monitoring equipment in the low-voltage flexible distribution network power supply system, the installed sensors and monitoring equipment include voltage sensor, current sensor, liquid level sensor, intelligent electric meter, power quality monitoring equipment and intelligent terminal, the voltage sensor is used to measure the voltage value in the power system and convert it into measurable and transmissible signal, the current sensor is used to measure the current value in the circuit and transform the large current signal into small current signal through electrical electromagnetic induction principle, the liquid level sensor is used to collect the liquid level in the oil pump, oil tank, battery and water tank, the intelligent electric meter is used to store and process a large amount of electric energy data by using digital signal processing technology, and the electric energy data is transmitted to the host computer through communication means, the power quality monitoring equipment is used to monitor and analyze the power quality in the low-voltage flexible distribution network power supply system in real time, and the intelligent terminal is used to convert the running state of the power equipment collected by the sensor into electric signal and process and transmit it.

3. The power control method for low voltage flexible distribution network power supply system according to claim 2, characterized in that: When processing and analyzing the data collected by the sensor and monitoring device to understand the current operation state and load condition of the low-voltage flexible distribution network power supply system, it includes the following steps: S21: data cleaning, including removing duplicate data, processing missing values, correcting error data and standardizing data format and unit; S22: data conversion, including data type conversion, data encoding and data normalization; S23: Data aggregation, including aggregating data by dimensions and calculating statistics, wherein the selected dimensions include time, location, and category, and the calculated statistics include mean, median, and standard deviation; S24: Data analysis and visualization, applying statistical methods and machine learning algorithms to identify patterns, trends, and outliers in the data, and presenting the analysis results in the form of charts and graphs.

4. The power control method for low voltage flexible distribution network power supply system according to claim 3, characterized in that: When processing missing values, the principle formula used is: Where y is the estimated value of the missing value, (x1, y1) and (x2, y2) are the coordinates of the two adjacent points of the missing value in the coordinate system, and x is the horizontal coordinate of the missing value.

5. The power control method for low voltage flexible distribution network power supply system according to claim 4, characterized in that: When identifying the actual operating state of the low-voltage flexible distribution network power supply system based on the results of data processing and analysis, the actual operating state of the low-voltage flexible distribution network power supply system is identified according to the following rules: A11: Analyze the voltage and current of each incoming line, whether it is within a certain set range, if the voltage and current of a certain incoming line is lower than the set threshold, it indicates that the incoming line is not in operation; A12: Analyze the power provided by each incoming line to the system, if the power contribution of a certain incoming line is lower than the threshold, it indicates that the incoming line is not in operation; A13: If only one incoming line has normal voltage, current and power data, and other incoming lines have data lower than the threshold, it is judged that the low-voltage flexible distribution network power supply system is currently in single incoming line operation mode.

6. The power control method for low voltage flexible distribution network power supply system according to claim 5, characterized in that: In the control mode of single incoming line operation mode control, the control steps executed are: S31: Energy storage charging control, according to the state of the energy storage system and the system demand, control the energy storage device to charge or discharge, ensure that the energy storage device can provide enough energy support when needed; S32: Emergency power support control, when monitoring that a certain incoming line has power shortage or failure, through the control of the flexible converter, the power of the energy storage system and the distributed photovoltaic system is quickly transferred to the power shortage line, realizing emergency power support; S33: Flexible converter reactive power control, adjust the reactive power output of the flexible converter to improve the reactive power balance of the low-voltage flexible distribution network power supply system, and improve the voltage stability and power factor of the low-voltage flexible distribution network power supply system.

7. The power control method for low voltage flexible distribution network power supply system according to claim 6, characterized in that: In the control mode of multi-incoming line operation mode control, the control steps executed are: S41: Zone power support control, according to the power load situation of each incoming line, the zone power support control is carried out, through the control of the flexible converter, the power is transferred from the incoming line with lighter load to the incoming line with heavier load, realizing the balanced distribution of power; S42: Emergency power support control, when monitoring that a certain incoming line has serious failure or power shortage, through the control of the flexible converter, emergency power support is realized; S43: Flexible converter reactive power control, adjust the reactive power output of the flexible converter to maintain the reactive power balance and voltage stability of the system.

8. The power control method for low voltage flexible distribution network power supply system according to claim 7, characterized in that: When identifying the fault points in the low-voltage flexible distribution network power supply system by processing and analyzing the data collected by sensors and monitoring devices, and taking targeted treatment measures according to the location and cause of the fault points, the following steps are included: S51: Fault monitoring, using intelligent sensing technology and big data analysis technology to analyze the data collected by sensors and monitoring devices to timely discover fault points in the power grid; S52: Fault judgment, according to the monitored data, combined with the preset fault judgment logic, to judge the type, location and impact range of the fault; S53: Isolation operation, after determining the fault point, through the control equipment in the low-voltage flexible distribution network power supply system, the fault area is isolated from the low-voltage flexible distribution network power supply system to prevent the spread of the fault; S54: Start island operation mode, realize load island operation through the flexible converter, ensure the continuity of power supply in the non-fault area; S55: Adjust the control strategy of the flexible converter to maintain stable voltage and frequency and ensure power supply quality; S56: Source-load balance control, by real-time acquisition of the electrical quantity of the whole micro-grid, judge whether the system is source-load balanced, if the source-load is unbalanced, adjust the charge-discharge strategy of the energy storage system and switch the load to restore balance; S57: Fault repair, after fault repair, re-evaluate and decide whether to restore grid-connected operation, if decided to grid-connected, adjust the control strategy of the flexible converter, make the island system gradually synchronized with the main grid, and finally realize grid-connected.

9. The power control method for low voltage flexible distribution network power supply system according to claim 8, characterized in that: After processing and analyzing the data collected by sensors and monitoring devices to understand the current operating status and load condition of the low-voltage flexible distribution network power supply system, the following steps are included: S61: According to the system design and equipment specifications, determine the rated load value of each line, and according to the rated load value, determine the overload protection trigger threshold of each line; S62: Real-time calculation of the actual load value of each line; S63: When the actual load value of the line reaches the overload protection trigger threshold, trigger the overload protection operation, according to the importance of the line, use one of the two overload protection operations of circuit interruption and power limitation to protect the line.

10. The power control method for low voltage flexible distribution network power supply system according to claim 9, characterized in that: When setting the coordination control unit and automatically adjusting the output power and voltage level of each part according to the preset control strategy and algorithm, the following steps are included: S71: Process and analyze the collected data to monitor the operating status and load condition of the low-voltage flexible distribution network power supply system in real time; S72: Identify abnormal states and potential risks of the low-voltage flexible distribution network power supply system, including overload, short circuit and voltage fluctuation; S73: According to the real-time monitored state of the low-voltage flexible distribution network power supply system and the preset control strategy library, match the corresponding control strategy; S74: According to the matched control strategy, automatically adjust the output power and voltage level of each part in the low-voltage flexible distribution network power supply system; S75: Adjusted system state is monitored and verified again to ensure that the adjustment effect meets the expectation.

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