Power distribution network voltage regulation method and device and electronic equipment

Abstract

The invention provides a power distribution network voltage regulation method and device and electronic equipment, and belongs to the technical field of new energy consumption. The method comprises the following steps: determining an output power regulation result of all photovoltaic inverters connected to the power distribution network based on a comparison result of a current voltage measurement value of the power distribution network and a set voltage out-of-limit threshold value of the power distribution network; constructing a target function based on the output power adjustment results of all the photovoltaic inverters; the target function represents that the output power of all photovoltaic inverters is maximized under the condition that the voltage of the power distribution network does not exceed the set voltage out-of-limit threshold value; and solving the objective function, and adjusting the output power of all photovoltaic inverters based on the solving result of the objective function so as to realize that the voltage of the power distribution network does not exceed the set voltage out-of-limit threshold value. The method is used for solving the problem of voltage out-of-limit caused by high-density distributed photovoltaic access to the power distribution network.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy consumption, and particularly relates to a method for regulating the voltage of a distribution network, a device for regulating the voltage of a distribution network, an electronic device, a machine-readable storage medium, and a computer program product. Background Art

[0002] Distributed photovoltaic power generation, as a new model of comprehensive energy utilization, has the advantages of flexible form, low management and operation costs, etc. It has significant environmental benefits in the case of no noise, no air and water pollution. Distributed photovoltaic power generation is of great significance for optimizing the energy structure and achieving energy conservation and emission reduction.

[0003] When distributed photovoltaic power generation is connected to the grid on a small scale, its impact on the grid is minimal. However, when distributed photovoltaic power generation is connected to the grid on a large scale or concentrated on a certain power supply line, substation area or substation, it will have a greater impact on the grid. After distributed photovoltaic power generation is connected to the distribution network at a high density (in large quantities), due to the large number of access positions of distributed photovoltaics and the inconsistent access capacities of each distributed photovoltaic, the node voltage distribution law will be more complex, and there may be an increase in the voltage of multiple nodes, and even a situation where the voltage of a large number of nodes exceeds the upper limit. That is, it is urgent to solve the problem of voltage over-limit caused by high-density distributed photovoltaic access to the distribution network. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a method, device and electronic device for regulating the voltage of a distribution network to solve the problem of voltage over-limit caused by high-density distributed photovoltaic access to the distribution network.

[0005] To achieve the above purpose, the embodiments of the present invention provide a method for regulating the voltage of a distribution network, including: Based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network, determine the output power adjustment result for all photovoltaic inverters connected to the distribution network; Construct an objective function based on the output power adjustment results of all the photovoltaic inverters; the objective function represents maximizing the output power of all the photovoltaic inverters under the condition that the voltage of the distribution network does not exceed the set voltage over-limit threshold; Solve the objective function, and adjust the output power of all the photovoltaic inverters based on the solution result of the objective function to ensure that the voltage of the distribution network does not exceed the set voltage over-limit threshold.

[0006] Optionally, the step of determining the output power adjustment result for all the photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network includes: Repeat the following steps until the set stop condition is reached: Obtain the current voltage measurement value of the distribution network; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determine the product of the first proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determine the product of the second proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the absolute value of the difference between the first proportionality factor and 1 is greater than the absolute value of the difference between the second proportionality factor and 1.

[0007] Optionally, the first result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, the first proportionality factor is characterized as the first reduction proportionality factor, and when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determine the product of the first reduction proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, the second proportionality factor is characterized as the first increase proportionality factor, and when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the first increase proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the first reduction proportionality factor is less than 1, and the first increase proportionality factor is greater than 1.

[0008] Optionally, when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determining the product of the first increase proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, and the current output power of each photovoltaic inverter is less than the set output power, determine the minimum value between the product of the first increase ratio factor and the current output power of each photovoltaic inverter and the set output power as the output power adjustment result of each photovoltaic inverter.

[0009] Optionally, the method further includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, and the current output power of each photovoltaic inverter is greater than or equal to the set output power, determine the set output power as the output power adjustment result of each photovoltaic inverter.

[0010] Optionally, the first result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, the first ratio factor is characterized as the second increase ratio factor. When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the second increase ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, the second ratio factor is characterized as the second decrease ratio factor. When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determine the product of the second decrease ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the second increase ratio factor is greater than 1, the second decrease ratio factor is less than 1, and the second increase ratio factor is greater than the first increase ratio factor, and the second decrease ratio factor is greater than the first decrease ratio factor.

[0011] Optionally, the objective function is represented by the following formula: ; Wherein, is the set of all photovoltaic inverters connected to the distribution network, is the output power of the i-th photovoltaic inverter.

[0012] On the other hand, an embodiment of the present invention further provides a distribution network voltage regulation device, including: A comparison module, configured to determine the output power adjustment result of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network; A construction module, configured to construct an objective function based on the output power adjustment results of all the photovoltaic inverters; the objective function represents maximizing the output power of all the photovoltaic inverters under the condition that the distribution network voltage does not exceed the set voltage limit threshold; A solving module, configured to solve the objective function and adjust the output power of all the photovoltaic inverters based on the solution result of the objective function, so as to ensure that the distribution network voltage does not exceed the set voltage limit threshold.

[0013] Optionally, the determining the output power adjustment result of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network includes: Repeatedly execute the following steps until a set stop condition is reached: Obtain the current voltage measurement value of the distribution network; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is a first result, determine the product of the first scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is a second result, determine the product of the second scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the absolute value of the difference between the first scaling factor and 1 is greater than the absolute value of the difference between the second scaling factor and 1.

[0014] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the program, the above-mentioned distribution network voltage regulation method is implemented.

[0015] On the other hand, the present invention also provides a machine-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above-mentioned distribution network voltage regulation method is implemented.

[0016] On the other hand, the present invention also provides a computer program product, including a computer program which, when executed by a processor, implements the above-mentioned distribution network voltage regulation method.

[0017] Through the above technical solution, based on the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network, the present invention embodiment determines the output power regulation result of all photovoltaic inverters connected to the distribution network, then constructs an objective function based on the output power regulation results of all photovoltaic inverters, and finally maximizes the output power of all photovoltaic inverters by solving the objective function under the condition that the distribution network voltage does not exceed the set voltage overlimit threshold. The present invention embodiment realizes the solution to the voltage overlimit problem caused by high-density distributed photovoltaic access to the distribution network.

[0018] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. They are used to explain the embodiments of the present invention together with the following specific implementation, but do not constitute a limitation to the embodiments of the present invention. In the drawings: Figure 1 is one of the flow diagrams of the distribution network voltage regulation method provided by the present invention; Figure 2 is another flow diagram of the distribution network voltage regulation method provided by the present invention; Figure 3 is the structural diagram of the distribution network voltage regulation device provided by the present invention; Figure 4 is the structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will describe in detail the specific implementation of the embodiments of the present invention with reference to the drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present invention, and is not used to limit the embodiments of the present invention.

[0021] High-density photovoltaic grid connection will affect the power flow, node voltage, relay protection, and power quality of the distribution network. The excessive penetration rate, unreasonable grid connection location, and unreasonable grid connection capacity of distributed photovoltaic will have a series of adverse effects on the distribution network, and even the feeder voltage will exceed the limit, threatening the stable operation of the distribution network.

[0022] In view of this, the purpose of the embodiments of the present invention is to provide a distribution network voltage regulation method, device and electronic device to solve the voltage overlimit problem caused by high-density distributed photovoltaic access to the distribution network.

[0023] Method Embodiment Please refer to Figure 1 , an embodiment of the present invention provides a method for regulating the voltage of a distribution network, including: Step 100: Based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network, determine the output power regulation result for all photovoltaic inverters connected to the distribution network.

[0024] The electronic device can repeatedly obtain the current voltage measurement value of the distribution network within a certain detection period (for example, the detection period is one hour, and the interval between two adjacent detection periods is 5 minutes), repeatedly compare the current voltage measurement value of the distribution network with the set voltage over-limit threshold of the distribution network, and based on the comparison result, determine the output power regulation result for all photovoltaic inverters connected to the distribution network. For example, when the current voltage measurement value of the distribution network is greater than the set voltage over-limit threshold, it indicates that there is voltage over-limit caused by high-density distributed photovoltaic access to the distribution network at this time. Therefore, the idea of group regulation and control can be adopted to reduce the output power of all photovoltaic inverters through a unified regulation command. Specifically, it can be determined that the product of the current output power of each photovoltaic inverter and the reduction factor (for example, 0.95) is used as the latest output power of each photovoltaic inverter. When the current voltage measurement value of the distribution network is less than or equal to the set voltage over-limit threshold, it indicates that there is no voltage over-limit caused by high-density distributed photovoltaic access to the distribution network at this time. Therefore, the output power of the photovoltaic inverter can be appropriately increased, and the output power of all photovoltaic inverters can be increased through a unified regulation command. Specifically, it can be determined that the product of the current output power of each photovoltaic inverter and the increase factor (for example, 1.05) is used as the latest output power of each photovoltaic inverter.

[0025] The present invention adopts the idea of group regulation and control. First, a set voltage over-limit threshold is set for the distribution network line voltage (abbreviated as the distribution network voltage). When it is detected that the distribution network voltage exceeds the set voltage over-limit threshold, the output of all photovoltaic inverters is regulated through a unified regulation command to achieve coordination of the entire distributed photovoltaic system range, thereby achieving the global optimum of the distribution network voltage.

[0026] It should be noted that the output power of the photovoltaic inverter in the embodiment of the present invention refers to the active power of the photovoltaic inverter. The embodiment of the present invention does not consider the reactive power of the photovoltaic inverter.

[0027] Step 200: Construct an objective function based on the output power regulation results of all the photovoltaic inverters.

[0028] Based on the output power adjustment results of all photovoltaic inverters at each moment obtained in step 100, the electronic device constructs an objective function. The objective function represents maximizing the output power of all photovoltaic inverters under the condition that the distribution network voltage does not exceed the set voltage limit threshold.

[0029] In one embodiment, the objective function can be expressed by the following formula: ; Wherein, is the set of all photovoltaic inverters connected to the distribution network, is the output power of the i-th photovoltaic inverter.

[0030] In addition, constraint conditions can be set for the above objective function. For example, the constraint conditions can include voltage security constraint conditions, photovoltaic inverter capacity constraint conditions, power balance constraint conditions, etc.

[0031] In one embodiment, the voltage security constraint condition indicates that the voltage amplitudes of all nodes in the distribution network need to be within the allowable range: ; Where is the set of all nodes in the distribution network, is the voltage amplitude of node , and are the lower and upper limits of the node voltage respectively.

[0032] In one embodiment, the photovoltaic inverter capacity constraint condition characterizes that the output power of the photovoltaic inverter is limited by its rated capacity: ; Where is the maximum active power capacity of the photovoltaic inverter at node , is the set of all nodes in the distribution network, is the output power of the photovoltaic inverter at node . Here, reactive power regulation is not considered, so there is no constraint on reactive power output.

[0033] In one embodiment, the power balance constraint condition is constructed based on the node power balance of the power flow equation: ; Wherein, is the output power of the photovoltaic inverter at node , P i LOAD is the power consumed by the load at node i, V i andV j are the voltage amplitudes of nodes i and j respectively, and are the line conductance and susceptance, is the phase angle difference of the node voltages.

[0034] Step 300, solve the objective function, and adjust the output powers of all photovoltaic inverters based on the solution result of the objective function, so as to ensure that the voltage of the distribution network does not exceed the set voltage over-limit threshold.

[0035] The electronic device can solve the objective function through various optimization methods (such as genetic algorithm, particle swarm algorithm, simulated annealing algorithm, etc.), obtain the maximum output powers of all photovoltaic inverters when the voltage of the distribution network does not exceed the set voltage over-limit threshold, and adjust the output powers of all photovoltaic inverters based on the maximum output powers of all photovoltaic inverters, so as to ensure that the voltage of the distribution network does not exceed the set voltage over-limit threshold.

[0036] The electronic device first determines the output power adjustment results of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network, so as to fully consider the distribution network structure and load level when connecting distributed photovoltaic power to the distribution network. Then, based on the output power adjustment results of all photovoltaic inverters, an objective function is constructed to maximize the output powers of all photovoltaic inverters when the voltage of the distribution network does not exceed the set voltage over-limit threshold, so as to realize that on the basis of reasonably analyzing the distributed photovoltaic acceptance level of the distribution network, the access amount of distributed photovoltaic power is increased as much as possible through a reasonable control strategy, ensuring the reasonable and orderly access of distributed photovoltaic power and improving the voltage fluctuation level of the distribution network.

[0037] In the embodiments of the present invention, based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network, the output power adjustment results of all photovoltaic inverters connected to the distribution network are determined, then an objective function is constructed based on the output power adjustment results of all photovoltaic inverters, and finally, by solving the objective function, the output powers of all photovoltaic inverters are maximized when the voltage of the distribution network does not exceed the set voltage over-limit threshold. The embodiments of the present invention solve the problem of voltage over-limit caused by the access of high-density distributed photovoltaic power to the distribution network.

[0038] In other aspects of the embodiments of the present invention, step 100, determining the output power adjustment results of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network, includes: Repeat the following steps until the set stop condition is reached: Step 110: Obtain the current voltage measurement value of the distribution network; Step 120: When the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network is the first result, determine the product of the first proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Step 130: When the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network is the second result, determine the product of the second proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; wherein, the absolute value of the difference between the first proportionality factor and 1 is greater than the absolute value of the difference between the second proportionality factor and 1.

[0039] The embodiment of the present invention adopts the idea of group regulation and control. Based on the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network, the output power of all photovoltaic inverters is regulated through a unified regulation command, with coarse adjustment first and then fine adjustment, that is, first use the first proportionality factor to adjust the output power of the photovoltaic inverter and then use the second proportionality factor to adjust the output power of the photovoltaic inverter, so that the current voltage measurement value of the distribution network gradually approaches the set voltage overlimit threshold of the distribution network.

[0040] For example, in one embodiment, the first result indicates that the current voltage measurement value of the distribution network is greater than the set voltage overlimit threshold, and the first proportionality factor is characterized as the first reduction proportionality factor. Step 120: When the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network is the first result, determine the product of the first proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter, including: when the current voltage measurement value of the distribution network is greater than the set voltage overlimit threshold, determine the product of the first reduction proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage threshold for over - limit, and the second scaling factor is characterized as the first increasing scaling factor. Step 130, when the comparison result between the current voltage measurement value of the distribution network and the set voltage threshold for over - limit of the distribution network is the second result, determine the product of the second scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter, including: when the current voltage measurement value of the distribution network is less than or equal to the set voltage threshold for over - limit, determine the product of the first increasing scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; wherein, the first decreasing scaling factor is less than 1, and the first increasing scaling factor is greater than 1.

[0041] In the embodiment of the present invention, a set voltage threshold for over - limit is first set for the distribution network voltage. When it is detected that the line voltage of the distribution network exceeds the over - limit threshold, all photovoltaic inverter outputs are regulated through a unified regulation instruction, first coarsely and then finely, so that the current voltage measurement value of the distribution network gradually approaches the set voltage threshold for over - limit. Based on the idea of first coarse - tuning and then fine - tuning, the absolute value of the difference between the first decreasing scaling factor and 1 can be set to be greater than the absolute value of the difference between the second scaling factor and 1. For example, in one embodiment, the first decreasing scaling factor can be set to 0.9; and the first increasing scaling factor can be set to 1.01.

[0042] For example, the embodiments of the present invention can define variables as follows: : The current voltage measurement value of the distribution network; : The set voltage threshold for over - limit; : The current output power of the photovoltaic inverter; : The first decreasing scaling factor; : The first increasing scaling factor.

[0043] First, when the current voltage measurement value of the distribution network is greater than the set voltage threshold for over - limit, determine the product of the first decreasing scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter. That is, , then the output power adjustment result of each photovoltaic inverter ; Here, the first decreasing scaling factor takes 0.9, that is, each adjustment makes the output power of each photovoltaic inverter decrease by 10%. This step will be repeatedly executed, and each time the current output power of each photovoltaic inverter is multiplied by the first decreasing scaling factor , until the current voltage measurement value of the distribution network is less than or equal to the set voltage threshold for over - limit.

[0044] When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the first increase factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter. That is, if , then .

[0045] Here, the first increase factor is taken as 1.01. When the current voltage measurement value of the distribution network is adjusted to be less than or equal to the set voltage limit threshold, each adjustment causes the output power of each photovoltaic inverter to increase by 1%. This step will be repeatedly executed, and each time the current output power of each photovoltaic inverter is multiplied by the first increase factor until the current voltage measurement value of the distribution network exceeds the set voltage limit threshold again.

[0046] It should be noted that the set stop condition for the repeated execution of steps 110 to 130 can be reaching the set time threshold, that is, the detection period ends. When the set stop condition is reached, the electronic device can obtain the output power adjustment results of all photovoltaic inverters whose distribution network voltages at each moment do not exceed the set voltage limit threshold.

[0047] Through the above control method combining the coarse adjustment and fine adjustment in two dimensions, the embodiment of the present invention makes the distribution voltage gradually approach the set voltage limit threshold. On the one hand, it improves the output power (active power) of the photovoltaic inverter as much as possible. On the other hand, it effectively solves the problem of voltage over-limit in the distribution network caused by high-density distributed photovoltaic access, and ensures the stable and safe operation of the distribution network.

[0048] In other aspects of the embodiment of the present invention, step 130, when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the first increase factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter, includes: when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold and the current output power of each photovoltaic inverter is less than the set output power, determine the minimum value between the product of the first increase factor and the current output power of each photovoltaic inverter and the set output power as the output power adjustment result of each photovoltaic inverter.

[0049] The electronic device redefines a variable : The set output power of the photovoltaic inverter (which may be the initial output power or rated output power of the photovoltaic inverter). In another embodiment, when the current voltage measurement value of the distribution network is less than or equal to the set voltage over-limit threshold, and the current output power of each photovoltaic inverter is less than the set output power, the minimum value of the product of the first increase proportional factor, the current output power of each photovoltaic inverter, and the set output power is determined as the output power adjustment result of each photovoltaic inverter. That is, if ,and ,but .

[0050] Similarly, the first increase scale factor Take 1.01, here determine the minimum value of the product of the first increase proportional factor and the current output power of each photovoltaic inverter and the set output power, as the output power adjustment result of each photovoltaic inverter, in order to ensure that the current output power of each photovoltaic inverter does not exceed the set output power Repeat this process, each time multiplying the current output power of the PV inverter by the first step-up scaling factor. , until the current output power of the PV inverter is restored to Or the current voltage measurement value of the distribution network exceeds the set voltage over-limit threshold again.

[0051] Furthermore, if the current measured voltage value of the distribution network is less than or equal to the set voltage over-limit threshold, and the current output power of each photovoltaic inverter is greater than or equal to the set output power, the electronic device determines the set output power as the output power adjustment result for each photovoltaic inverter. This ensures that the current output power of each photovoltaic inverter does not exceed the set output power of each photovoltaic inverter. Thus, this embodiment of the present invention ensures stable and safe operation of the distribution network while maximizing the output power of the photovoltaic inverters.

[0052] The embodiment of the present invention adopts the control method combining the above coarse adjustment and fine adjustment dual dimensions, comprehensively considering the set output power of the photovoltaic inverter, so that the distribution line voltage gradually approaches the over-limit threshold, further improving the output power of the photovoltaic inverter, and further effectively solving the voltage over-limit problem of high-density distributed photovoltaic access distribution network, thereby further ensuring the stable and safe operation of the distribution network.

[0053] In other aspects of the embodiments of the present invention, the first result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, and the first scaling factor is characterized as the second increase scaling factor. Step 120, when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter, includes: when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determining the product of the second increase scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter.

[0054] The second result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, and the second scaling factor is characterized as the second decrease scaling factor. Step 130, when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter, includes: when the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determining the product of the second decrease scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter. Wherein, the second increase scaling factor is greater than 1, the second decrease scaling factor is less than 1, and the second increase scaling factor is greater than the first increase scaling factor, and the second decrease scaling factor is greater than the first decrease scaling factor.

[0055] First, when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the second increase scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter. That is, , then the output power adjustment result of each photovoltaic inverter ; Here, the second increase scaling factor k up ’ can take 1.1, that is, each adjustment makes the output power of each photovoltaic inverter increase by 10%. This step will be repeatedly executed, and each time the current output power of each photovoltaic inverter is multiplied by the second increase scaling factor k up ’, until the current voltage measurement value of the distribution network is greater than the set voltage limit threshold.

[0056] When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determine the product of the second decrease scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter. That is, if , then .

[0057] Here, the second reduction factor k down ’ is taken as 0.99. When the current voltage measurement value of the distribution network is adjusted to be less than or equal to the set voltage limit threshold, each adjustment reduces the output power of each photovoltaic inverter by 1%. This step is repeated, and each time the current output power of each photovoltaic inverter is multiplied by the second reduction factor k down ’ until the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold.

[0058] Through the above control method combining the rough adjustment and fine adjustment in two dimensions, the distribution voltage gradually approaches the set voltage limit threshold in the embodiments of the present invention. On the one hand, the output power (active power output) of the photovoltaic inverter is increased as much as possible. On the other hand, the problem of voltage over-limit caused by high-density distributed photovoltaic access to the distribution network is effectively solved, ensuring the stable and safe operation of the distribution network.

[0059] In an exemplary embodiment, the following variables can be defined: : The current voltage measurement value of the distribution network; : The set voltage limit threshold; : The current output power of the photovoltaic inverter; : The first reduction factor; : The first increase factor; : The set output power of the photovoltaic inverter (which can be the initial output power or the rated output power of the photovoltaic inverter).

[0060] Please refer to Figure 2 , the flow of the distribution network voltage regulation method under high-density distributed photovoltaic access proposed in the embodiments of the present invention is as follows: Step 1: Initialize the current output power of the photovoltaic inverter ; Step 2: Measure the current voltage measurement value of the distribution network in real time ; Step 3: When , update to , and return to Step 2; Step 4: When , if , update to , and return to Step 2; otherwise, keep , and return to Step 2.

[0061] In the embodiments of the present invention, a set voltage over-limit threshold is first set. Through a regulation method that combines the coarse adjustment and fine adjustment in a two-layer dimension, the distribution network voltage gradually approaches the set voltage over-limit threshold, thereby effectively solving the problem of voltage over-limit in the distribution network with high-density distributed photovoltaic access. Then, in the embodiments of the present invention, a distribution network voltage optimization control model (or objective function) is constructed with the goal of maximizing the output power of photovoltaic inverters when the voltage does not exceed the voltage over-limit threshold, and the output power of photovoltaic inverters at the grid connection points with voltage over-limit is regulated, thereby ensuring the stable and safe operation of the distribution network.

[0062] In summary, the distribution network voltage regulation method in the embodiments of the present invention has the following advantages: 1. The embodiments of the present invention adopt the idea of group regulation and control, regulate the output power of all photovoltaic inverters through a unified regulation instruction, and through the regulation that combines the coarse adjustment and fine adjustment in a two-layer dimension, the distribution network voltage gradually approaches the set voltage over-limit threshold, thereby effectively solving the problem of voltage over-limit in the distribution network with high-density distributed photovoltaic access.

[0063] 2. The embodiments of the present invention construct a distribution network voltage optimization control model (or objective function) with the goal of maximizing the output power of photovoltaic inverters when the voltage does not exceed the set voltage over-limit threshold, improve the access amount of distributed photovoltaic as much as possible, ensure the reasonable and orderly access of distributed photovoltaic, and improve the voltage fluctuation level of the distribution network.

[0064] Device embodiments Please refer to Figure 3 , on the other hand, the embodiments of the present invention also provide a distribution network voltage regulation device, including: A comparison module 301, configured to determine the output power adjustment result of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network; A construction module 302, configured to construct an objective function based on the output power adjustment result of all photovoltaic inverters; the objective function represents maximizing the output power of all photovoltaic inverters when the distribution network voltage does not exceed the set voltage over-limit threshold; A solution module 303, configured to solve the objective function and adjust the output power of all photovoltaic inverters based on the solution result of the objective function to ensure that the distribution network voltage does not exceed the set voltage over-limit threshold.

[0065] Optionally, the determining the output power adjustment result of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network includes: Repeatedly execute the following steps until a set stop condition is reached: Obtain the current voltage measurement value of the distribution network; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determine the product of the first proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determine the product of the second proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the absolute value of the difference between the first proportionality factor and 1 is greater than the absolute value of the difference between the second proportionality factor and 1.

[0066] Optionally, the first result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, the first proportionality factor is characterized as the first reduction proportionality factor, and when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determine the product of the first reduction proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, the second proportionality factor is characterized as the first increase proportionality factor, and when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the first increase proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the first reduction proportionality factor is less than 1, and the first increase proportionality factor is greater than 1.

[0067] Optionally, when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determining the product of the first increase proportionality factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold and the current output power of each photovoltaic inverter is less than the set output power, determine the minimum value between the product of the first increase ratio factor and the current output power of each photovoltaic inverter and the set output power as the output power adjustment result of each photovoltaic inverter.

[0068] Optionally, the device further includes: A determination module, configured to determine the set output power as the output power adjustment result of each photovoltaic inverter when the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold and the current output power of each photovoltaic inverter is greater than or equal to the set output power.

[0069] Optionally, the first result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, the first ratio factor is characterized as the second increase ratio factor. When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the second increase ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, the second ratio factor is characterized as the second decrease ratio factor. When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determine the product of the second decrease ratio factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the second increase ratio factor is greater than 1, the second decrease ratio factor is less than 1, and the second increase ratio factor is greater than the first increase ratio factor, and the second decrease ratio factor is greater than the first decrease ratio factor.

[0070] Optionally, the objective function is represented by the following formula: ; Wherein, is the set of all photovoltaic inverters connected to the distribution network. is the output power of the i-th photovoltaic inverter.

[0071] The distribution network voltage regulation device includes a processor and a memory. The above comparison module 301, construction module 302, solution module 303, etc. are all stored in the memory as program units, and the corresponding functions are implemented by the processor executing the above program units stored in the memory.

[0072] The processor contains a kernel, and the kernel retrieves the corresponding program units from the memory. One or more kernels can be set.

[0073] The memory may include non-permanent memory in computer-readable media, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. The memory includes at least one storage chip.

[0074] Figure 4 Illustrates a schematic diagram of the physical structure of an electronic device, such as Figure 4 shown. The electronic device may include: a processor 410, a communication interface 420, a memory 430, and a communication bus 440. Among them, the processor 410, the communication interface 420, and the memory 430 complete mutual communication through the communication bus 440. The processor 410 can call the logical instructions in the memory 430 to execute the distribution network voltage regulation method, which includes: determining the output power regulation result of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network; constructing an objective function based on the output power regulation result of all photovoltaic inverters; the objective function characterizes maximizing the output power of all photovoltaic inverters under the condition that the distribution network voltage does not exceed the set voltage limit threshold; solving the objective function, and adjusting the output power of all photovoltaic inverters based on the solution result of the objective function to achieve that the distribution network voltage does not exceed the set voltage limit threshold.

[0075] In addition, when the logical instructions in the above-mentioned memory 430 can be implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0076] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program that can be stored on a machine-readable storage medium. When the computer program is executed by a processor, the computer can execute a method for regulating the voltage of a distribution network. The method includes: determining the output power adjustment results for all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network; constructing an objective function based on the output power adjustment results of all the photovoltaic inverters; the objective function represents maximizing the output power of all photovoltaic inverters on the premise that the distribution network voltage does not exceed the set voltage overlimit threshold; solving the objective function, and adjusting the output power of all photovoltaic inverters based on the solution result of the objective function to achieve that the distribution network voltage does not exceed the set voltage overlimit threshold.

[0077] On another aspect, the present invention also provides a machine-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is used to execute a method for regulating the voltage of a distribution network. The method includes: determining the output power adjustment results for all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage overlimit threshold of the distribution network; constructing an objective function based on the output power adjustment results of all the photovoltaic inverters; the objective function represents maximizing the output power of all photovoltaic inverters on the premise that the distribution network voltage does not exceed the set voltage overlimit threshold; solving the objective function, and adjusting the output power of all photovoltaic inverters based on the solution result of the objective function to achieve that the distribution network voltage does not exceed the set voltage overlimit threshold.

[0078] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0079] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. A method for regulating the voltage of a distribution network, characterized in that, Including: Based on the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network, determine the output power adjustment result of all photovoltaic inverters connected to the distribution network; Construct an objective function based on the output power adjustment results of all the photovoltaic inverters; The objective function represents maximizing the output power of all photovoltaic inverters when the distribution network voltage does not exceed the set voltage limit threshold; Solve the objective function, and adjust the output power of all photovoltaic inverters based on the solution result of the objective function to ensure that the distribution network voltage does not exceed the set voltage limit threshold.

2. The method for regulating the voltage of a distribution network according to claim 1, wherein The determining the output power adjustment result of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network includes: Repeat the following steps until the set stop condition is reached: Obtain the current voltage measurement value of the distribution network; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determine the product of the first scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determine the product of the second scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the absolute value of the difference between the first scaling factor and 1 is greater than the absolute value of the difference between the second scaling factor and 1.

3. The distribution network voltage regulation method according to claim 2, wherein The first result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, the first scaling factor is characterized as the first reduction scaling factor, and when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determine the product of the first reduction scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, the second scaling factor is characterized as the first increase scaling factor, and when the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determine the product of the first increase scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Among them, the first reduction factor is less than 1, and the first increase factor is greater than 1.

4. The method for regulating the voltage of a distribution network according to claim 3, wherein When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determining the product of the first increase factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold and the current output power of each photovoltaic inverter is less than the set output power, determining the minimum value between the product of the first increase factor and the current output power of each photovoltaic inverter and the set output power as the output power adjustment result of each photovoltaic inverter.

5. The method for regulating the voltage of a distribution network according to claim 4, wherein The method further includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold and the current output power of each photovoltaic inverter is greater than or equal to the set output power, determining the set output power as the output power adjustment result of each photovoltaic inverter.

6. The method for regulating the voltage of a distribution network according to claim 3, characterized in that The first result indicates that the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, the first factor is characterized as the second increase factor. When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the first result, determining the product of the first factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is less than or equal to the set voltage limit threshold, determining the product of the second increase factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; The second result indicates that the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, the second factor is characterized as the second reduction factor. When the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network is the second result, determining the product of the second factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter includes: When the current voltage measurement value of the distribution network is greater than the set voltage limit threshold, determining the product of the second reduction factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Among them, the second increase factor is greater than 1, the second reduction factor is less than 1, and the second increase factor is greater than the first increase factor, and the second reduction factor is greater than the first reduction factor.

7. The method for regulating the voltage of a distribution network according to claim 1, characterized in that The objective function is represented by the following formula: ； Among them, is the set of all photovoltaic inverters connected to the distribution network, is the output power of the i-th photovoltaic inverter.

8. A distribution network voltage regulation device, characterized in that, Including: A comparison module for determining the output power adjustment results of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage limit threshold of the distribution network; A construction module for constructing an objective function based on the output power adjustment results of all the photovoltaic inverters; The objective function represents maximizing the output power of all photovoltaic inverters under the condition that the voltage of the distribution network does not exceed the set voltage over-limit threshold. A solving module is configured to solve the objective function and adjust the output power of all photovoltaic inverters based on the solution result of the objective function, so as to ensure that the voltage of the distribution network does not exceed the set voltage over-limit threshold.

9. The distribution network voltage regulating device according to claim 8, wherein Determining the adjustment result of the output power of all photovoltaic inverters connected to the distribution network based on the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network includes: Repeatedly execute the following steps until a set stop condition is reached: Obtain the current voltage measurement value of the distribution network; When the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network is a first result, determine the product of the first scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; When the comparison result between the current voltage measurement value of the distribution network and the set voltage over-limit threshold of the distribution network is a second result, determine the product of the second scaling factor and the current output power of each photovoltaic inverter as the output power adjustment result of each photovoltaic inverter; Wherein, the absolute value of the difference between the first scaling factor and 1 is greater than the absolute value of the difference between the second scaling factor and 1.

10. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, When the processor executes the program, it implements the distribution network voltage regulation method according to any one of claims 1 to 7.

11. A machine-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the distribution network voltage regulation method according to any one of claims 1 to 7.

12. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the distribution network voltage regulation method according to any one of claims 1 to 7.

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