A source-load-storage collaborative control method and system for power distribution network distributed new energy consumption

Abstract

A source-load-storage collaborative control method and system for power distribution network distributed new energy consumption, the method collects multi-source operation data of the power distribution network, identifies new energy consumption related operation states of the power distribution network, forms a comprehensive evaluation result of new energy consumption state, and divides the operation state of the power distribution network into normal consumption, energy storage priority absorption, flexible load collaborative absorption, output limitation early warning and power shortage support state according to the result, and further generates control instructions such as energy storage charging and discharging, flexible load response, new energy output adjustment and upper grid power support; the system is used to execute the method, which can avoid the judgment deviation caused by only relying on the source-load power difference or single operation index for control, and realize the source-load-storage collaborative control under the conditions of distributed new energy consumption in place, safe operation of energy storage, effective participation of flexible load and voltage and power flow safety constraints of the power distribution network.

Description

Technical Field

[0001] This invention belongs to the field of distributed renewable energy consumption and source-load-storage coordinated control technology in distribution networks, specifically relating to a source-load-storage coordinated control method and system for distributed renewable energy consumption in distribution networks. Background Technology

[0002] Traditional power distribution networks are gradually transforming from unidirectional power supply networks into active power distribution networks with multiple sources, multiple loads, and multiple energy flow coupling. The output of new energy sources is significantly affected by weather, seasons, and time periods, exhibiting randomness, volatility, and intermittency, which can easily lead to mismatches between the output and load demand in time and space.

[0003] Under the condition of high proportion of distributed renewable energy access, problems such as local surplus of renewable energy, curtailment of wind and solar power, reverse power flow, voltage exceeding limit, and heavy load on lines or transformers are prone to occur in the operation of the distribution network. Energy storage devices can absorb surplus renewable energy and participate in peak shaving and valley filling. However, without a comprehensive assessment of the SOC status and adjustable capacity, problems such as overcharging, over-discharging, frequent charging and discharging, or underutilization of energy storage can easily occur. Meanwhile, although flexible loads, electric vehicles, and transferable loads have certain adjustment capabilities, the triggering conditions and control priorities for their participation in renewable energy consumption are still not clear enough. Although existing research has carried out work on renewable energy output prediction, energy storage optimization scheduling, demand response control, and source-load-storage synergistic optimization, and has made some progress in improving renewable energy consumption capacity and reducing operating costs, some methods still mainly rely on source-load power difference or single operating constraints for control, and lack a control mechanism that directly transforms the comprehensive evaluation results of multi-dimensional operating status into energy storage, flexible load, and renewable energy output adjustment commands.

[0004] Therefore, it is necessary to propose a source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks. This method incorporates renewable energy output status on the source side, electricity consumption and flexible response capabilities on the load side, energy storage SOC and adjustability margin, and distribution network voltage and power flow security status into a unified assessment. It constructs a comprehensive assessment mechanism for consumption status, adjustment margin, and safety boundary, and generates control strategies such as energy storage charging and discharging, flexible load response, renewable energy output adjustment, and power support from the upper-level grid based on the assessment results. This aims to improve the local consumption capacity of distributed renewable energy and the safe and stable operation level of the distribution network. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a source-load-storage coordinated control method and system for distributed renewable energy consumption in distribution networks. This method no longer relies solely on the power difference between renewable energy output and load demand for scheduling. Instead, it comprehensively considers the source-load power matching status, node voltage status, line and transformer power flow status, energy storage SOC adjustability margin, and flexible load adjustability margin to form a comprehensive evaluation result of renewable energy consumption status. This result is then directly mapped to control strategies such as energy storage charging and discharging, flexible load response, renewable energy output limitation, or upstream grid power support.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks includes the following steps: S1: Collect multi-source operation data of the power distribution network; S2: Based on the collected operational data, identify the relevant operational status of the distribution network for renewable energy consumption and form a comprehensive assessment result of the renewable energy consumption status; S3: Based on the comprehensive assessment results of the new energy consumption status of the distribution network, the current operating status of the distribution network is divided into normal consumption status, energy storage priority absorption status, flexible load coordinated absorption status, power output limitation early warning status, and power deficit support status. S4: Based on the operating status of renewable energy consumption, the system generates corresponding source-load-storage coordinated control commands. After the control is executed, the system modifies the evaluation results and control strategies for the next control cycle based on node voltage, line power flow, transformer load rate, energy storage SOC, and renewable energy consumption effect, thus forming closed-loop control.

[0007] In S1, the multi-source operation data of the distribution network includes distributed photovoltaic power output, wind power output, load power, energy storage SOC, energy storage chargeable and dischargeable power, flexible load adjustable capacity, node voltage, line power flow, transformer load rate, and power exchanged with the upstream grid during the current control cycle.

[0008] In S2, the relevant operating status of renewable energy consumption is identified, and a comprehensive assessment result of the renewable energy consumption status is generated, specifically including: 2.1: Calculation of the matching state between new energy output and source load power; 2.2: Distribution network safety status, i.e., calculation of node voltage status, line and transformer power flow status; 2.3: Calculation of Energy Storage SOC State and Flexible Load Adjustable State; 2.4: Based on the relevant operating status of new energy consumption described in 2.1 to 2.3, construct a comprehensive evaluation index for the status of new energy consumption.

[0009] In section 2.1, the calculation of the matching state between the power output of new energy sources and the power of the source load is as follows: In the t Within each control cycle, the system calculates the total output of new energy sources based on the output of distributed photovoltaic and wind power, using the following formula: (1); In equation (1), Contribute to the overall development of new energy. Contribute to photovoltaic power Powering wind power; Further calculations are performed on the source-load power difference and source-load matching status index, using the following formulas: (2); In equation (2), The difference between source and load power. For load power, This is an indicator of the source-load matching status. The base capacity for the distribution network or transformer substation; when This indicates that the output of new energy sources exceeds the load demand; when When, it indicates that the output of new energy sources is insufficient; when When the value is close to 0, it indicates that the source and load are basically balanced.

[0010] Section 2.2, the calculation of the distribution network security status includes the calculation of node voltage status, line and transformer power flow status, as detailed below: To avoid voltage overshooting after distributed renewable energy access, the system calculates node voltage status indicators using the following formula: (3); In equation (3), This refers to the node voltage status indicator. For the first i Node voltage, Rated voltage, For permissible voltage deviation limits; The larger the value, the closer the node voltage is to the safety boundary; The power flow status indicators for lines and transformers are calculated using the following formulas: (4); In equation (4), It serves as an indicator of current flow status. For the first k Trend of the line For the line's allowable transmission power, For transformer power, This refers to the rated capacity of the transformer. The larger the value, the closer the line and transformer are to the operating boundary.

[0011] In section 2.3, the calculation of energy storage SOC and flexible load adjustability is as follows: The SOC of the energy storage system is collected in real time and recursively corrected based on the actual charging and discharging power of the energy storage in the previous control cycle. The recursive correction calculation formula for energy storage SOC is as follows: (5); In equation (5), For the first The energy storage state of charge for each control cycle; The energy storage state of charge is the same as that of the previous control cycle; and These are the energy storage charging power and the discharging power, respectively. and These are the energy storage charging efficiency and the discharging efficiency, respectively. This refers to the rated capacity of the energy storage. To control the cycle; To prevent overcharging and over-discharging of energy storage, the system sets an upper limit for the energy storage SOC. Lower limit and SOC security margin ; when At that time, it is determined that the energy storage SOC is close to the upper limit; when At that time, the energy storage SOC is determined to be close to the lower limit; When renewable energy sources are abundant, the energy storage SOC absorbs the excess power through charging; when renewable energy sources are insufficient, the energy storage SOC supports the load through discharging. The energy storage adjustability margin is calculated based on the energy storage SOC state, using the following formula: (6); In equation (6), For adjustable energy storage margin, and These are the maximum charging power and maximum discharging power of energy storage, respectively. and They are respectively Upper and lower limits, For the rated capacity of energy storage, These are the charging and discharging efficiencies, respectively. To control the cycle, To prevent extremely small positive numbers with a denominator of zero; The adjustable margin of flexible load is expressed as: (7); In equation (7), To provide adjustable margin for flexible load, For transferable load capacity, It can reduce load capacity. Adjustable capacity for controllable charging load.

[0012] Section 2.4 establishes a comprehensive evaluation index for the status of new energy consumption as follows: (8); In equation (8), It serves as a comprehensive evaluation indicator for the status of new energy consumption. These are the weighting coefficients; , and Constraints used to reflect source-load mismatch, voltage deviation, and power flow approaching the boundary; and Used to reflect the regulation capabilities of energy storage and flexible loads; , and The larger the value, the stronger the absorption constraint; and The larger the value, the more the system still has a strong ability to regulate, which can alleviate the tension in the absorption of new energy sources.

[0013] In S3, the system presets a source-load balance threshold. Comprehensive assessment of low threshold and security boundary threshold , Used to determine whether the source and load power are basically balanced. This is used to determine whether the comprehensive evaluation index for the status of new energy consumption is at a low level. Used to determine whether node voltage, line power flow, and transformer load rate are close to the safety boundary; When the power source and load are basically balanced, the comprehensive evaluation indicators of renewable energy absorption are at a low level, and the node voltage, line power flow, and transformer load rate are close to the safety boundary, the system determines that the distribution network is in a normal absorption state, as expressed below: (9); In equation (9), This is an indicator of the source-load matching status. It serves as a comprehensive evaluation indicator for the status of new energy consumption. This refers to the node voltage status indicator. For power flow status indicators of lines and transformers; When the output of new energy sources exceeds the load demand, the comprehensive evaluation indicators increase, and the energy storage still has a charging margin, the system determines that the distribution network is in a state of priority absorption by energy storage, as expressed below: (10); In equation (10), This indicates that the output of new energy sources exceeds the load demand; To comprehensively evaluate the low threshold; This is the minimum adjustable margin threshold for energy storage; This is the upper limit of the energy storage SOC; For the safety margin of energy storage SOC; When the output of new energy sources exceeds the load demand, the energy storage absorption capacity is insufficient or the energy storage SOC is close to its upper limit, and the flexible load still has an adjustable margin, the system determines that the distribution network is in a flexible load cooperative absorption state, as expressed below: (11); In equation (11), This indicates that the output of new energy sources exceeds the load demand; This is the minimum adjustable margin threshold for energy storage; This is the minimum adjustable margin threshold for flexible loads; For the safety margin of energy storage SOC; When the output of new energy sources exceeds the load demand, the energy storage and flexible load regulation capabilities are insufficient, and the node voltage is high. Line flow When any value in the equation approaches the safety boundary, the system determines that the distribution network is in a power output limitation warning state, as expressed below: (12); In equation (12), This indicates that the output of new energy sources exceeds the load demand; This is the minimum adjustable margin threshold for energy storage; This is the minimum adjustable margin threshold for flexible loads; For the safety margin of energy storage SOC, For safety boundary threshold, It serves as an indicator of current flow status. This refers to the node voltage status indicator; when When this occurs, it indicates that the output of new energy sources is insufficient, and the system determines that the distribution network is in a state of power shortage support.

[0014] In S4, based on the new energy consumption operation status of the distribution network, the system generates corresponding distribution network source-load-storage coordinated control commands according to the distribution network source-load-storage coordinated control strategy. The mapping relationship between the comprehensive assessment results of the renewable energy consumption status of the distribution network and the source-load-storage coordinated control strategy of the distribution network is as follows: When the system determines that the distribution network is in a normal absorption state, under the condition that the node voltage, line power flow and transformer load rate all meet the safety constraints, the system controls the new energy to maintain the maximum absorption output. When the system determines that the distribution network is in a state of priority energy storage absorption, it prioritizes the charging of energy storage to absorb surplus new energy power. When the system determines that the distribution network is in a flexible load collaborative absorption state, the system calls on transferable loads to use electricity in advance, or calls on controllable charging loads to increase electricity use, in order to continue to absorb surplus renewable energy power. When the system determines that the distribution network is in a power output restriction warning state, it restricts the power output of some new energy sources. When the system determines that the distribution network is in a state of power shortage support, it prioritizes controlling the energy storage discharge to support the load; when the energy storage SOC is close to the lower limit or the energy storage discharge capacity is insufficient, it calls interruptible loads to reduce the current power consumption, or calls transferable loads to transfer part of the power consumption to a later time period; when there is still a power shortage after the energy storage discharge and flexible load response, the upstream grid supplements the power. After the distribution network source-load-storage coordinated control strategy is implemented, the system will revise the evaluation results and control strategy for the next control cycle based on node voltage, line power flow, transformer load rate, energy storage SOC and new energy consumption effect, thus forming a closed-loop control. The evaluation result correction refers to adjusting the weight of the corresponding indicators based on the actual operational deviation, and the control strategy correction refers to fine-tuning the trigger threshold of each state based on the execution feedback.

[0015] A source-load-storage coordinated control system for distributed renewable energy consumption in distribution networks includes distributed renewable energy units, conventional load units, flexible load units, energy storage systems, distribution network equipment, and an upstream power grid and a source-load-storage coordinated control center. The input terminals of the source-load-storage collaborative control center are connected to the distributed new energy unit, conventional load unit, flexible load unit, and energy storage system via one-way communication to collect the operating data of each terminal. The output terminal of the source-load-storage collaborative control center is bidirectionally connected to the distribution network equipment and the upstream power grid for exchanging operating parameters and dispatching instructions; The source-load-storage collaborative control center includes a data acquisition module, a status identification module, a comprehensive evaluation module, a strategy generation module, a control execution module, and a feedback correction module. The data acquisition module is used to collect and preprocess multi-source operation data from various terminal units, distribution networks, and upstream power grids. The status recognition module is used to identify the relevant operating status of new energy consumption based on preprocessed data; The comprehensive assessment module is used to construct a comprehensive assessment index for the status of new energy consumption, and to weight and integrate the multi-dimensional status identification results to generate a comprehensive assessment result for the status of new energy consumption. The status classification module is used to classify the grid operation status based on the comprehensive assessment results of the renewable energy consumption status. The strategy generation module is used to map and generate corresponding coordinated control commands based on the divided distribution network operating status. The control execution module is used to send coordinated control commands to each terminal unit and power distribution network equipment and execute them; The feedback correction module has its input end connected to the operation feedback end of the control execution module, and its output end connected to the input ends of the comprehensive evaluation module and the strategy generation module, respectively. It is used to correct the evaluation parameters and control strategies for the next control cycle based on the actual operation feedback, so as to realize closed-loop control.

[0016] The main beneficial effects of this invention are as follows: (1) This invention no longer judges solely based on the power difference between renewable energy output and load demand, but comprehensively considers the source-load matching status, node voltage status, line and transformer power flow status, energy storage SOC status, and flexible load adjustability. Through comprehensive evaluation of multi-dimensional operating status, it can more accurately reflect the current capacity of the distribution network to accept distributed renewable energy, and avoid deviations in control strategies caused by a single indicator.

[0017] (2) When renewable energy output is in surplus, the system prioritizes the use of energy storage charging to absorb the surplus power, and calls on flexible loads to participate in the absorption when the energy storage absorption capacity is insufficient or the SOC is close to the upper limit; only when neither energy storage nor flexible loads can meet the absorption demand, and the voltage and power flow are close to the safety boundary, will the output of renewable energy be restricted. This method can reduce the risks of wind and solar curtailment and reverse power flow, while reducing safety hazards such as voltage over-limit, line overload and transformer overload.

[0018] (3) The present invention dynamically generates control strategies based on the energy storage SOC state, energy storage adjustability margin, and flexible load adjustability, which can avoid overcharging, over-discharging, frequent charging and discharging of energy storage, or ineffective use of flexible loads. After the control is executed, the system can also make feedback corrections for the next control cycle based on node voltage, line power flow, energy storage SOC, and new energy absorption effect, thereby improving the adaptability of source-load-storage coordinated control to new energy fluctuations and load changes. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a flowchart of the source-load-storage coordinated control method for distributed renewable energy consumption in the distribution network according to the present invention; Figure 2 This is a structural diagram of the power distribution network source-load-storage coordinated control system of the present invention; Figure 3 This is a mapping diagram of the comprehensive evaluation results of the new energy consumption status and the control strategy of the present invention; Figure 4This is a comparison chart of the renewable energy absorption rate under different control schemes in embodiments of the present invention; Figure 5 The curves show the maximum node voltage variation under different control schemes in embodiments of the present invention. Figure 6 The curves showing the variation of the maximum load rate of the line under different control schemes in embodiments of the present invention are shown. Figure 7 The figures show the energy storage SOC variation curves under different control schemes in embodiments of the present invention. Figure 8 The figures show the power variation curves of the upper-level power grid under different control schemes in embodiments of the present invention. Detailed Implementation

[0021] Example 1: This example consists of a total of... Figure 1 The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks, as shown, includes the following steps: S1: Collect multi-source operation data of the power distribution network; S2: Based on the collected operational data, identify the relevant operational status of the distribution network for renewable energy consumption and form a comprehensive assessment result of the renewable energy consumption status; S3: Based on the comprehensive assessment results of the new energy consumption status of the distribution network, the current operating status of the distribution network is divided into normal consumption status, energy storage priority absorption status, flexible load coordinated absorption status, power output limitation early warning status, and power deficit support status. S4: Based on the operating status of renewable energy consumption, the system generates corresponding source-load-storage coordinated control commands. After the control is executed, the system modifies the evaluation results and control strategies for the next control cycle based on node voltage, line power flow, transformer load rate, energy storage SOC, and renewable energy consumption effect, thus forming closed-loop control.

[0022] In S1, the multi-source operation data of the distribution network includes distributed photovoltaic power output, wind power output, load power, energy storage SOC, energy storage chargeable and dischargeable power, flexible load adjustable capacity, node voltage, line power flow, transformer load rate, and power exchanged with the upstream grid during the current control cycle.

[0023] In S2, the relevant operating status of renewable energy consumption is identified, and a comprehensive assessment result of the renewable energy consumption status is generated, specifically including: 2.1: Calculation of the matching state between new energy output and source load power; 2.2: Distribution network safety status, i.e., calculation of node voltage status, line and transformer power flow status; 2.3: Calculation of Energy Storage SOC State and Flexible Load Adjustable State; 2.4: Based on the relevant operating status of new energy consumption described in 2.1 to 2.3, construct a comprehensive evaluation index for the status of new energy consumption.

[0024] In section 2.1, the calculation of the matching state between the power output of new energy sources and the power of the source load is as follows: In the t Within each control cycle, the system calculates the total output of new energy sources based on the output of distributed photovoltaic and wind power, using the following formula: (1); In equation (1), Contribute to the overall development of new energy. Contribute to photovoltaic power It provides power for wind power.

[0025] Further calculations are performed on the source-load power difference and source-load matching status index, using the following formulas: (2); In equation (2), The difference between source and load power. For load power, This is an indicator of the source-load matching status. The base capacity for the distribution network or transformer substation; when This indicates that the output of new energy sources exceeds the load demand; when When, it indicates that the output of new energy sources is insufficient; when When the value is close to 0, it indicates that the source and load are basically balanced.

[0026] Section 2.2, the calculation of the distribution network security status includes the calculation of node voltage status, line and transformer power flow status, as detailed below: To avoid voltage overshooting after distributed renewable energy access, the system calculates node voltage status indicators using the following formula: (3); In equation (3), This refers to the node voltage status indicator. For the first i Node voltage, Rated voltage, For permissible voltage deviation limits; The larger the value, the closer the node voltage is to the safety boundary; The power flow status indicators for lines and transformers are calculated using the following formulas: (4); In equation (4), It serves as an indicator of current flow status. For the first k Trend of the line For the line's allowable transmission power, For transformer power, This refers to the rated capacity of the transformer. The larger the value, the closer the line and transformer are to the operating boundary.

[0027] In section 2.3, the calculation of energy storage SOC and flexible load adjustability is as follows: The SOC of the energy storage system is collected in real time and recursively corrected based on the actual charging and discharging power of the energy storage in the previous control cycle. The recursive correction calculation formula for energy storage SOC is as follows: (5); In equation (5), For the first The energy storage state of charge for each control cycle; The energy storage state of charge is the same as that of the previous control cycle; and These are the energy storage charging power and the discharging power, respectively. and These are the energy storage charging efficiency and the discharging efficiency, respectively. This refers to the rated capacity of the energy storage. To control the cycle; To prevent overcharging and over-discharging of energy storage, the system sets an upper limit for the energy storage SOC. Lower limit and SOC security margin ; when At that time, it is determined that the energy storage SOC is close to the upper limit; when At that time, the energy storage SOC is determined to be close to the lower limit; When renewable energy sources are abundant, the energy storage SOC absorbs the excess power through charging; when renewable energy sources are insufficient, the energy storage SOC supports the load through discharging. The energy storage adjustability margin is calculated based on the energy storage SOC state, using the following formula: (6); In equation (6), For adjustable energy storage margin, and These are the maximum charging power and maximum discharging power of energy storage, respectively. and They are respectively Upper and lower limits, For the rated capacity of energy storage, These are the charging and discharging efficiencies, respectively. To control the cycle, To prevent extremely small positive numbers with a denominator of zero; The adjustable margin of flexible load is expressed as: (7); In equation (7), To provide adjustable margin for flexible load, For transferable load capacity, It can reduce load capacity. Adjustable capacity for controllable charging load.

[0028] Section 2.4 establishes a comprehensive evaluation index for the status of new energy consumption as follows: (8); In equation (8), It serves as a comprehensive evaluation indicator for the status of new energy consumption. These are the weighting coefficients; , and Constraints used to reflect source-load mismatch, voltage deviation, and power flow approaching the boundary; and Used to reflect the regulation capabilities of energy storage and flexible loads; , and The larger the value, the stronger the absorption constraint; and The larger the value, the more the system still has a strong ability to regulate, which can alleviate the tension in the absorption of new energy sources.

[0029] In S3, the system presets a source-load balance threshold. Comprehensive assessment of low threshold and security boundary threshold , Used to determine whether the source and load power are basically balanced. This is used to determine whether the comprehensive evaluation index for the status of new energy consumption is at a low level. Used to determine whether node voltage, line power flow, and transformer load rate are close to the safety boundary; When the power source and load are basically balanced, the comprehensive evaluation indicators of renewable energy absorption are at a low level, and the node voltage, line power flow, and transformer load rate are close to the safety boundary, the system determines that the distribution network is in a normal absorption state, as expressed below: (9); In equation (9), This is an indicator of the source-load matching status. It serves as a comprehensive evaluation indicator for the status of new energy consumption. This refers to the node voltage status indicator. For power flow status indicators of lines and transformers; When the output of new energy sources exceeds the load demand, the comprehensive evaluation indicators increase, and the energy storage still has a charging margin, the system determines that the distribution network is in a state of priority absorption by energy storage, as expressed below: (10); In equation (10), This indicates that the output of new energy sources exceeds the load demand; To comprehensively evaluate the low threshold; This is the minimum adjustable margin threshold for energy storage; This is the upper limit of the energy storage SOC; For the safety margin of energy storage SOC; When the output of new energy sources exceeds the load demand, the energy storage absorption capacity is insufficient or the energy storage SOC is close to its upper limit, and the flexible load still has an adjustable margin, the system determines that the distribution network is in a flexible load cooperative absorption state, as expressed below: (11); In equation (11), This indicates that the output of new energy sources exceeds the load demand; This is the minimum adjustable margin threshold for energy storage; This is the minimum adjustable margin threshold for flexible loads; For the safety margin of energy storage SOC; When the output of new energy sources exceeds the load demand, the energy storage and flexible load regulation capabilities are insufficient, and the node voltage is high. Line flow When any value in the equation approaches the safety boundary, the system determines that the distribution network is in a power output limitation warning state, as expressed below: (12); In equation (12), This indicates that the output of new energy sources exceeds the load demand; This is the minimum adjustable margin threshold for energy storage; This is the minimum adjustable margin threshold for flexible loads; For the safety margin of energy storage SOC, For safety boundary threshold, It serves as an indicator of current flow status. This refers to the node voltage status indicator; when When this occurs, it indicates that the output of new energy sources is insufficient, and the system determines that the distribution network is in a state of power shortage support.

[0030] In S4, based on the new energy consumption operation status of the distribution network, the system generates corresponding distribution network source-load-storage coordinated control commands according to the distribution network source-load-storage coordinated control strategy. The mapping relationship between the comprehensive assessment results of the renewable energy consumption status of the distribution network and the source-load-storage coordinated control strategy of the distribution network is as follows: When the system determines that the distribution network is in a normal absorption state, under the condition that the node voltage, line power flow and transformer load rate all meet the safety constraints, the system controls the new energy to maintain the maximum absorption output. When the system determines that the distribution network is in a state of priority energy storage absorption, it prioritizes the charging of energy storage to absorb surplus new energy power. When the system determines that the distribution network is in a flexible load collaborative absorption state, the system calls on transferable loads to use electricity in advance, or calls on controllable charging loads to increase electricity use, in order to continue to absorb surplus renewable energy power. When the system determines that the distribution network is in a power output restriction warning state, it restricts the power output of some new energy sources. When the system determines that the distribution network is in a state of power shortage support, it prioritizes controlling the energy storage discharge to support the load; when the energy storage SOC is close to the lower limit or the energy storage discharge capacity is insufficient, it calls interruptible loads to reduce the current power consumption, or calls transferable loads to transfer part of the power consumption to a later time period; when there is still a power shortage after the energy storage discharge and flexible load response, the upstream grid supplements the power. After the distribution network source-load-storage coordinated control strategy is implemented, the system will revise the evaluation results and control strategy for the next control cycle based on node voltage, line power flow, transformer load rate, energy storage SOC and new energy absorption effect, thus forming a closed-loop control.

[0031] Example 2: This example provides the following... Figure 2 The above describes a source-load-storage coordinated control system for distributed renewable energy consumption in distribution networks, which includes distributed renewable energy units, conventional load units, flexible load units, energy storage systems, distribution network equipment, and an upstream power grid and a source-load-storage coordinated control center. The input terminals of the source-load-storage collaborative control center are connected to the distributed new energy unit, conventional load unit, flexible load unit, and energy storage system via one-way communication to collect the operating data of each terminal. The output terminal of the source-load-storage collaborative control center is bidirectionally connected to the distribution network equipment and the upstream power grid for exchanging operating parameters and dispatching instructions; The source-load-storage collaborative control center includes a data acquisition module, a status identification module, a comprehensive evaluation module, a strategy generation module, a control execution module, and a feedback correction module. The data acquisition module is used to collect and preprocess multi-source operation data from various terminal units, distribution networks, and upstream power grids. The status recognition module is used to identify the relevant operating status of new energy consumption based on preprocessed data; The comprehensive assessment module is used to construct a comprehensive assessment index for the status of new energy consumption, and to weight and integrate the multi-dimensional status identification results to generate a comprehensive assessment result for the status of new energy consumption. The status classification module is used to classify the grid operation status based on the comprehensive assessment results of the renewable energy consumption status. The strategy generation module is used to map and generate corresponding coordinated control commands based on the divided distribution network operating status. The control execution module is used to send coordinated control commands to each terminal unit and power distribution network equipment and execute them; The feedback correction module has its input end connected to the operation feedback end of the control execution module, and its output end connected to the input ends of the comprehensive evaluation module and the strategy generation module, respectively. It is used to correct the evaluation parameters and control strategies for the next control cycle based on the actual operation feedback, so as to realize closed-loop control.

[0032] Example 3: This example provides a verification example of a source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks.

[0033] To verify the technical effectiveness of the method of the present invention, a 10kV distribution network containing distributed photovoltaic, wind power, energy storage systems, conventional loads and flexible loads was selected as the simulation object.

[0034] The simulation period was set to a typical day, and the control period was 1 hour. Data such as photovoltaic output, wind power output, conventional load power, energy storage SOC, node voltage, line load rate, and upstream grid support power were collected during each control period. The operating range of energy storage system SOC was set to 20% to 90%, the allowable range of node voltage was set to 0.95 to 1.05 pu, and the maximum line load rate limit was set to 100%.

[0035] To illustrate the control effect of the method of the present invention, the following three comparison schemes are set up: Option 1: No source-load-storage coordinated control is adopted; the system operates only at the maximum output of new energy sources. Option 2: Use only energy storage control. When there is a surplus of new energy, control the charging of energy storage; when there is a shortage of new energy, control the discharging of energy storage. Option 3: Using the source-load-storage coordinated control method described in this invention, based on the comprehensive evaluation results of the renewable energy consumption status, energy storage charging and discharging, flexible load response, renewable energy output limitation, and upstream grid power support commands are generated sequentially.

[0036] The evaluation indicators are selected as renewable energy absorption rate, wind and solar power curtailment, maximum node voltage, maximum line load rate, energy storage SOC exceeding limit, and supplementary power from the upstream grid. The simulation results are shown in Table 1. Table 1 Comparison of simulation results under different control schemes

[0037] Depend on Figures 4-8 It can be seen that without coordinated control, the renewable energy absorption rate is only 87.3%, the amount of wind and solar power curtailed is 1101.6 kWh, the maximum node voltage reaches 1.073 pu, and the maximum line load rate reaches 112.0%, posing risks of voltage exceeding limits and line overload. After adopting energy storage control alone, the renewable energy absorption rate increases to 93.1%, and the amount of wind and solar power curtailed decreases to 312.8 kWh. However, the maximum node voltage still reaches 1.058 pu, and the energy storage SOC is close to the upper limit, indicating that relying solely on energy storage still has insufficient regulation capacity.

[0038] After adopting the method of this invention, the renewable energy consumption rate increased to 98.6%, the amount of wind and solar power curtailed decreased to 20.0 kWh, the maximum node voltage decreased to 1.035 pu, the maximum line load rate decreased to 80.0%, the energy storage SOC did not exceed the limit, and the supplementary power from the upstream grid also decreased from 1890.0 kWh to 279.0 kWh.

[0039] Simulation results show that the present invention can improve the distributed renewable energy absorption capacity, reduce the risk of wind and solar curtailment and operation exceeding limits, and reduce the dependence on the power support of the upper-level grid under the conditions of meeting voltage, power flow and energy storage SOC safety constraints, demonstrating significant technological progress.

Claims

1. A source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks, characterized in that, Includes the following steps: S1: Collect multi-source operation data of the power distribution network; S2: Based on the collected operational data, identify the relevant operational status of the distribution network for renewable energy consumption and form a comprehensive assessment result of the renewable energy consumption status; S3: Based on the comprehensive assessment results of the new energy consumption status of the distribution network, the current operating status of the distribution network is divided into normal consumption status, energy storage priority absorption status, flexible load coordinated absorption status, power output limitation early warning status, and power deficit support status. S4: Based on the operating status of renewable energy consumption, the system generates corresponding source-load-storage coordinated control commands. After the control is executed, the system modifies the evaluation results and control strategies for the next control cycle based on node voltage, line power flow, transformer load rate, energy storage SOC, and renewable energy consumption effect, thus forming closed-loop control.

2. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 1, characterized in that: In S1, the multi-source operation data of the distribution network includes distributed photovoltaic power output, wind power output, load power, energy storage SOC, energy storage chargeable and dischargeable power, flexible load adjustable capacity, node voltage, line power flow, transformer load rate, and power exchanged with the upstream grid during the current control cycle.

3. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 1, characterized in that: In S2, the relevant operating status of renewable energy consumption is identified, and a comprehensive assessment result of the renewable energy consumption status is generated, specifically including: 2.1: Calculation of the matching state between new energy output and source load power; 2.2: Distribution network safety status, i.e., calculation of node voltage status, line and transformer power flow status; 2.3: Calculation of Energy Storage SOC State and Flexible Load Adjustable State; 2.4: Based on the relevant operating status of new energy consumption described in 2.1 to 2.3, construct a comprehensive evaluation index for the status of new energy consumption.

4. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 3, characterized in that: In section 2.1, the calculation of the matching state between the power output of new energy sources and the power of the source load is as follows: In the t Within each control cycle, the system calculates the total output of new energy sources based on the output of distributed photovoltaic and wind power, using the following formula: （1）； In equation (1), Contribute to the overall development of new energy. Contribute to photovoltaic power Powering wind power; Further calculations are performed on the source-load power difference and source-load matching status index, using the following formulas: （2）； In equation (2), The difference between source and load power. For load power, This is an indicator of the source-load matching status. The base capacity for the distribution network or transformer substation; when This indicates that the output of new energy sources exceeds the load demand; when When, it indicates that the output of new energy sources is insufficient; when When the value is close to 0, it indicates that the source and load are basically balanced.

5. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 3, characterized in that: Section 2.2, the calculation of the distribution network security status includes the calculation of node voltage status, line and transformer power flow status, as detailed below: To avoid voltage overshooting after distributed renewable energy access, the system calculates node voltage status indicators using the following formula: （3）； In equation (3), This refers to the node voltage status indicator. For the first i Node voltage, Rated voltage, For permissible voltage deviation limits; The power flow status indicators for lines and transformers are calculated using the following formulas: （4）； In equation (4), It serves as an indicator of current flow status. For the first k Trend of the line For the line's allowable transmission power, For transformer power, This refers to the rated capacity of the transformer.

6. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 3, characterized in that: In section 2.3, the calculation of energy storage SOC and flexible load adjustability is as follows: The SOC of the energy storage system is collected in real time and recursively corrected based on the actual charging and discharging power of the energy storage in the previous control cycle. The recursive correction calculation formula for energy storage SOC is as follows: （5）； In equation (5), For the first The energy storage state of charge for each control cycle; The energy storage state of charge is the same as that of the previous control cycle; and These are the energy storage charging power and the discharging power, respectively. and These are the energy storage charging efficiency and the discharging efficiency, respectively. This refers to the rated capacity of the energy storage. To control the cycle; To prevent overcharging and over-discharging of energy storage, the system sets an upper limit for the energy storage SOC. Lower limit and SOC security margin ; when At that time, it is determined that the energy storage SOC is close to the upper limit; when At that time, the energy storage SOC is determined to be close to the lower limit; When renewable energy sources are abundant, the energy storage SOC absorbs the excess power through charging; when renewable energy sources are insufficient, the energy storage SOC supports the load through discharging. The energy storage adjustability margin is calculated based on the energy storage SOC state, using the following formula: （6）； In equation (6), For adjustable energy storage margin, and These are the maximum charging power and maximum discharging power of energy storage, respectively. and They are respectively Upper and lower limits, For the rated capacity of energy storage, These are the charging and discharging efficiencies, respectively. To control the cycle, To prevent extremely small positive numbers with a denominator of zero; The adjustable margin of flexible load is expressed as: （7）； In equation (7), To provide adjustable margin for flexible load, For transferable load capacity, It can reduce load capacity. Adjustable capacity for controllable charging load.

7. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 3, characterized in that: Section 2.4 establishes a comprehensive evaluation index for the status of new energy consumption as follows: （8）； In equation (8), It serves as a comprehensive evaluation indicator for the status of new energy consumption. These are the weighting coefficients; , and Constraints used to reflect source-load mismatch, voltage deviation, and power flow approaching the boundary; and Used to reflect the regulation capabilities of energy storage and flexible loads.

8. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 1, characterized in that: In S3, the system presets a source-load balance threshold. Comprehensive assessment of low threshold and security boundary threshold , Used to determine whether the source and load power are basically balanced. This is used to determine whether the comprehensive evaluation index for the status of new energy consumption is at a low level. Used to determine whether node voltage, line power flow, and transformer load rate are close to the safety boundary; When the power of the source and load are basically balanced, the comprehensive evaluation indicators of the renewable energy absorption status are at a low level, and the node voltage, line power flow, and transformer load rate are not close to the safety boundary, the system determines that the distribution network is in a normal absorption state, as expressed below: （9）； In equation (9), This is an indicator of the source-load matching status. It serves as a comprehensive evaluation indicator for the status of new energy consumption. This refers to the node voltage status indicator. For power flow status indicators of lines and transformers; When the output of new energy sources exceeds the load demand, the comprehensive evaluation indicators increase, and the energy storage still has a charging margin, the system determines that the distribution network is in a state of priority absorption by energy storage, as expressed below: （10）； In equation (10), This indicates that the output of new energy sources exceeds the load demand; To comprehensively evaluate the low threshold; This is the minimum adjustable margin threshold for energy storage; This is the upper limit of the energy storage SOC; For the safety margin of energy storage SOC; When the output of new energy sources exceeds the load demand, the energy storage absorption capacity is insufficient or the energy storage SOC is close to its upper limit, and the flexible load still has an adjustable margin, the system determines that the distribution network is in a flexible load cooperative absorption state, as expressed below: （11）； In equation (11), This indicates that the output of new energy sources exceeds the load demand; This is the minimum adjustable margin threshold for energy storage; This is the minimum adjustable margin threshold for flexible loads; For the safety margin of energy storage SOC; When the output of new energy sources exceeds the load demand, the energy storage and flexible load regulation capabilities are insufficient, and the node voltage is high. Line flow When any value in the equation approaches the safety boundary, the system determines that the distribution network is in a power output limitation warning state, as expressed below: （12）； In equation (12), This indicates that the output of new energy sources exceeds the load demand; This is the minimum adjustable margin threshold for energy storage; This is the minimum adjustable margin threshold for flexible loads; For the safety margin of energy storage SOC, For safety boundary threshold, It serves as an indicator of current flow status. This refers to the node voltage status indicator; when When this occurs, it indicates that the output of new energy sources is insufficient, and the system determines that the distribution network is in a state of power shortage support.

9. The source-load-storage coordinated control method for distributed renewable energy consumption in distribution networks according to claim 1, characterized in that: In S4, based on the new energy consumption operation status of the distribution network, the system generates corresponding distribution network source-load-storage coordinated control commands according to the distribution network source-load-storage coordinated control strategy. The mapping relationship between the comprehensive assessment results of the renewable energy consumption status of the distribution network and the source-load-storage coordinated control strategy of the distribution network is as follows: When the system determines that the distribution network is in a normal absorption state, under the condition that the node voltage, line power flow and transformer load rate all meet the safety constraints, the system controls the new energy to maintain the maximum absorption output. When the system determines that the distribution network is in a state of priority energy storage absorption, it prioritizes the charging of energy storage to absorb surplus new energy power. When the system determines that the distribution network is in a flexible load collaborative absorption state, the system calls on transferable loads to use electricity in advance, or calls on controllable charging loads to increase electricity use, in order to continue to absorb surplus renewable energy power. When the system determines that the distribution network is in a power output restriction warning state, it restricts the power output of some new energy sources. When the system determines that the distribution network is in a state of power shortage support, priority is given to controlling the discharge of energy storage to support the load; When the energy storage SOC is close to the lower limit or the energy storage discharge capacity is insufficient, interruptible loads are called to reduce the current electricity consumption, or transferable loads are called to transfer part of the electricity consumption to a later time period; when there is still a power deficit after the energy storage discharges and the flexible loads respond, the upstream power grid will supplement the power. After the distribution network source-load-storage coordinated control strategy is implemented, the system will revise the evaluation results and control strategy for the next control cycle based on node voltage, line power flow, transformer load rate, energy storage SOC and new energy absorption effect, thus forming a closed-loop control.

10. A source-load-storage coordinated control system for distributed renewable energy consumption in distribution networks, characterized in that: It includes distributed new energy units, conventional load units, flexible load units, energy storage systems, distribution network equipment, and the upper-level power grid and source-load-storage collaborative control center; The input terminals of the source-load-storage collaborative control center are connected to the distributed new energy unit, conventional load unit, flexible load unit, and energy storage system via one-way communication to collect the operating data of each terminal. The output terminal of the source-load-storage collaborative control center is bidirectionally connected to the distribution network equipment and the upstream power grid for exchanging operating parameters and dispatching instructions; The source-load-storage collaborative control center includes a data acquisition module, a status identification module, a comprehensive evaluation module, a strategy generation module, a control execution module, and a feedback correction module. The data acquisition module is used to collect and preprocess multi-source operation data from various terminal units, distribution networks, and upstream power grids. The status recognition module is used to identify the relevant operating status of new energy consumption based on preprocessed data; The comprehensive assessment module is used to construct a comprehensive assessment index for the status of new energy consumption, and to weight and integrate the multi-dimensional status identification results to generate a comprehensive assessment result for the status of new energy consumption. The status classification module is used to classify the grid operation status based on the comprehensive assessment results of the renewable energy consumption status. The strategy generation module is used to map and generate corresponding coordinated control commands based on the divided distribution network operating status. The control execution module is used to send coordinated control commands to each terminal unit and power distribution network equipment and execute them; The feedback correction module has its input end connected to the operation feedback end of the control execution module, and its output end connected to the input ends of the comprehensive evaluation module and the strategy generation module, respectively. It is used to correct the evaluation parameters and control strategies for the next control cycle based on the actual operation feedback, so as to realize closed-loop control.

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