Power distribution network voltage harmonic distortion treatment method and system based on scene running state

Abstract

The present application belongs to the technical field of power quality management and control of distribution network, and provides a method and system for voltage harmonic distortion management of distribution network based on scene operation state, which judges the management scene according to the state of node equipment of the distribution network; adopts a harmonic compensation method of multiple active power filters based on the least square method to analyze the influence of compensation current on node harmonic voltage distortion, selects the corresponding voltage management target value according to the judgment result of the management scene, and obtains the harmonic compensation current result under the corresponding management scene; based on the harmonic compensation current result, the voltage management target value is solved, and an adaptive solving adjustment mechanism based on harmonic dynamic change is introduced; according to the preset compensation current fluctuation judgment condition, the difference between the current and previous compensation current change values is compared, the size of the time interval of the solving compensation current change value is dynamically adjusted based on the difference, and the present application realizes the adaptation of distortion management to harmonic variation speed.

Description

Technical Field

[0001] This invention belongs to the field of power quality management technology for distribution networks, specifically relating to a method and system for managing voltage harmonic distortion in distribution networks based on scenario-based operating conditions. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the large-scale integration of distributed photovoltaic (PV) and other new energy power generation equipment and power electronic devices into AC / DC hybrid distribution networks, harmonic pollution has become increasingly prominent. Distributed PV, as a typical harmonic source, exhibits strong intermittency and random fluctuations in power generation depending on sunlight and weather conditions. Furthermore, the grid connection of numerous power electronic devices results in distributed network harmonics being decentralized, dynamic, and unevenly distributed in time and space. Existing mitigation methods typically employ uniform mitigation targets across various operating scenarios, failing to develop tailored solutions based on scenario differences. This leads to problems such as significant harmonic interference affecting harmonic-sensitive equipment and delayed compensation response in scenarios with rapid harmonic fluctuations, making dynamic adaptation across multiple scenarios impossible.

[0004] On the other hand, existing governance methods generally use a fixed solution time interval, without considering the actual rate of harmonic variation, which leads to problems such as delayed compensation in scenarios with drastic harmonic variation and waste of resources in scenarios with slow variation. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a method and system for managing voltage harmonic distortion in distribution networks based on scenario operating conditions. This invention achieves management under differentiated harmonic voltage targets.

[0006] According to some embodiments, the present invention adopts the following technical solution:

[0007] A method for mitigating voltage harmonic distortion in a distribution network based on scenario operating conditions includes the following steps:

[0008] The governance scenario is determined based on the status of the equipment at the distribution network nodes;

[0009] A harmonic compensation method based on the least squares method for multi-active power filters is adopted to analyze the impact of compensation current on node harmonic voltage distortion. Based on the judgment results of the governance scenario, the corresponding voltage governance target value is selected, and the harmonic compensation current result under the corresponding governance scenario is obtained.

[0010] Based on the harmonic compensation current results, the solution is performed according to the voltage control target value. During the solution process, an adaptive solution adjustment mechanism based on the dynamic changes of harmonics is introduced. According to the preset compensation current fluctuation judgment conditions, the difference between the current and previous compensation current change values ​​is compared. Based on the difference, the time interval for solving the compensation current change value is dynamically adjusted to adapt to the harmonic change speed.

[0011] As an alternative implementation method, the process of determining the governance scenario based on the status of distribution network node equipment includes: judging from four aspects in sequence based on the status of distribution network node equipment, including sensitive node access, sensitive node operation type, date characteristics, and intraday time period characteristics. There are two governance scenarios: Scenario 1 addresses the need to minimize harmonic compensation current; Scenario 2 is applicable to harmonic sensitive load operation scenarios and addresses the different needs of governance objectives for different nodes.

[0012] As an alternative implementation method, the process of determining the governance scenario based on the status of distribution network node equipment includes: defining nodes with more stringent harmonic distortion rate requirements as sensitive nodes based on information about the harmonic distortion rate requirements of individual nodes in historical operating data, obtaining the sensitive node access judgment value, and if the first... i If the sensitive node access judgment value of a node is the first target value, it indicates that a sensitive device has been accessed, and the process proceeds to the next step to continue judgment; if no sensitive device is found, the judgment result is Scenario 1.

[0013] Based on historical operational data regarding whether sensitive node access devices are continuously connected throughout the day, a sensitive node operation type judgment value is obtained. If the first... i If the sensitive node operation type judgment value of each node is the second target value, it indicates that there are sensitive devices that are continuously connected throughout the day, and the judgment result is scenario two; if not, proceed to the next step to continue the judgment.

[0014] Based on historical operational data throughout the year, patterns in the access and operation of sensitive devices at individual nodes are identified. Based on the set of operational dates, date characteristic judgment values ​​are derived. If a certain value exists... i If the date feature judgment value of a node is the first target value, it indicates that there is a sensitive device in operation on that date, but it is uncertain whether it is in the working period. If so, proceed to the next step to continue the judgment; if not, the judgment result is Scenario 1.

[0015] Based on historical daily operational data, the patterns of access and operation of sensitive devices on individual nodes within a single day's time period are obtained. Based on the set of operational time periods, characteristic judgment values ​​for each time period within the day are derived. If a certain value exists... i If the intraday time period characteristic judgment value of a node is the first target value, it indicates that there is a sensitive device in working state within that date and time period, and the judgment result is Scenario 2; if it does not exist, the judgment result is Scenario 1.

[0016] As an alternative implementation method, the process of analyzing the impact of compensation current on node harmonic voltage distortion using a multi-active power filter harmonic compensation method based on the least squares method includes: acquiring basic information of the distribution network, including the network impedance matrix, the number and location of active power filters connected and voltage detection values, and performing data preprocessing;

[0017] Based on the network impedance matrix information, the number of network nodes is defined as follows: n The number of active power filters connected is p To form relevant access points n × p The impedance matrix is ​​calculated based on the voltage detection values ​​at each point. h For subharmonic voltage, set the solution variables, calculate the compensation current values ​​of each active power filter output, and set the target voltage value. This represents the expected value of the harmonic voltage after compensation, while the target voltage value is the total network node voltage value before compensation. Impact of injecting compensation current on node voltage sum;

[0018] Based on the least squares method, with the goal of minimizing the sum of squared errors, the required compensation current value for each active power filter is calculated, i.e., the solution quantity.

[0019] As an alternative implementation method, the process of selecting the corresponding voltage control target value based on the judgment result of the control scenario includes: Scenario 1 is the scenario of minimizing harmonic compensation current control, which uses the minimum output compensation current of the active power filter to achieve the target harmonic distortion rate of the node, with the target being the lowest harmonic distortion rate that does not affect the normal operation of the equipment, and the target voltage value. The value can be set or adjusted according to operational and maintenance needs;

[0020] Scenario 2 is a harmonic-sensitive load management scenario, targeting distribution networks operating with harmonic-sensitive loads. Based on the varying sensitivities of node equipment to voltage distortion, target voltage values ​​are set. The values ​​of each element in the code are revised.

[0021] As a further defined implementation method, the target voltage value The process of revising the values ​​of each element includes:

[0022] ;

[0023] In the formula, For the first i Target voltage value for each node For the first i Sensitive node access judgment value for a node. For the first i Sensitive node operation type judgment value for nodes. For the first i Date feature judgment value of the node, For the first i The intraday time-period characteristic judgment condition score of the node. For the first i The node h The minimum required voltage for subharmonics at this voltage level and for both odd and even orders. For the first i The node h The limiting voltage for subharmonics at this voltage level and for odd / even orders is set according to the equipment requirements.

[0024] As an alternative implementation method, the process of solving based on the harmonic compensation current result and the voltage control target value includes: setting an initial time interval value, using the harmonic compensation current result as the initial value of the compensation current value, and obtaining the current time. t Voltage value detection value The target voltage value remains constant, and the solution is obtained using the least squares method.

[0025] Update the compensation current value variable by updating the compensation current value variable with the obtained compensation current change value after the time interval T, and repeat the above steps after waiting for the time interval T.

[0026] As an optional implementation, the compensation current fluctuation judgment condition includes: judging whether it has already passed. N If the time interval is specified, continue the evaluation; otherwise, keep the time interval unchanged.

[0027] Determine the magnitude of the compensation current fluctuation judgment value. If it exceeds the limit, it indicates that the harmonic changes are drastic. Adjust the time interval. If it is between the upper and lower limits, no change is needed.

[0028] The count of time intervals restarts until it reaches the limit again. N A time interval.

[0029] As a further defined implementation, the calculation process for the compensation current fluctuation judgment value includes: calculating two key values: the current difference and the current count value. for t Time period and before N The sum of the compensation current changes over each time interval; current count value for t Time period and before N The total number of times the change in compensation current exceeds the total change in compensation current within a time interval;

[0030] The judgment criterion for compensation current fluctuation is based on the current difference. and count value Weighted composition.

[0031] The process of determining the magnitude of the compensation current fluctuation judgment value includes:

[0032] ;

[0033] In the formula, T For time intervals, The change per unit time interval This is the upper limit of the current fluctuation judgment value. This is the lower limit value for judging current fluctuations.

[0034] A distribution network voltage harmonic distortion mitigation system based on scenario operation status includes:

[0035] The governance scenario judgment module is configured to judge the governance scenario based on the status of the distribution network node equipment;

[0036] The module for determining the target value of the governance is configured to use a multi-active power filter harmonic compensation method based on the least squares method to analyze the impact of the compensation current on the harmonic voltage distortion of the node. Based on the judgment result of the governance scenario, the corresponding voltage governance target value is selected, and the harmonic compensation current result under the corresponding governance scenario is obtained.

[0037] The adaptive solution module is configured to solve the voltage control target value based on the harmonic compensation current result. During the solution process, an adaptive solution adjustment mechanism based on the dynamic change of harmonics is introduced. According to the preset compensation current fluctuation judgment condition, the difference between the current and previous compensation current change values ​​is compared. Based on the difference, the time interval of solving the compensation current change value is dynamically adjusted to adapt to the harmonic change speed.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] This invention addresses the problem that existing technologies lack a complete governance framework that matches multiple scenarios and dynamic harmonic changes, especially the lack of an adaptive adjustment mechanism for solving harmonic dynamic changes, which makes it impossible to achieve efficient collaborative governance and response of harmonics across the entire network. It proposes a compensation current solution method based on the least squares method in a collaborative compensation mode for multiple active power filters. This method combines dynamic adjustment of node voltage governance objectives for different scenarios. Scenario 1 follows the minimum harmonic distortion rate requirement without affecting normal equipment operation, while Scenario 2 adapts to the high requirements of sensitive nodes. This achieves precise and differentiated harmonic governance across the entire network, improving the targeting and effectiveness of harmonic governance.

[0040] This invention constructs an adaptive solution adjustment mechanism based on the dynamic changes of harmonics. It dynamically optimizes the time interval according to the judgment condition of compensation current fluctuation, so as to adapt to the speed of harmonic changes. This solves the problem that fixed time intervals cannot match the dynamic fluctuations of harmonics and enhances the responsiveness of the governance strategy.

[0041] This invention integrates three core components: scenario judgment criteria based on node device status, differentiated governance objectives, and adaptive adjustment mechanism based on harmonic changes. It forms a complete governance framework that considers multiple scenarios and dynamic harmonic changes, fully leveraging the collaborative compensation potential of multiple active power filters. This significantly improves the efficiency and flexibility of harmonic governance in distribution networks and provides an efficient solution for harmonic governance under the widespread application of distributed energy and power electronic equipment in new power systems. Its applicability covers multiple distribution network operating conditions.

[0042] This invention establishes a scenario judgment criterion covering the operating status of the power distribution network, refines the operating type and time characteristics of sensitive nodes, realizes the scientific division of two governance scenarios, provides a clear scenario adaptation basis for targeted harmonic governance, and solves the problem that a single governance target is difficult to adapt to complex operating conditions.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0044] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0045] Figure 1 A flowchart of a distribution network voltage harmonic distortion mitigation method based on scenario operation status judgment provided in one embodiment;

[0046] Figure 2 A schematic diagram illustrating the scenario judgment criteria provided in one embodiment;

[0047] Figure 3 A flowchart for calculating compensation current commands is provided for one embodiment;

[0048] Figure 4 A schematic diagram of a time interval update module provided in one embodiment. Detailed Implementation

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0050] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0051] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0052] Where there is no conflict, the embodiments and features described in this application may be combined with each other.

[0053] Example 1

[0054] like Figure 1 As shown in this embodiment, a method for mitigating voltage harmonic distortion in a distribution network based on scenario operation status determination includes:

[0055] Step S1: Define the judgment criteria for the harmonic mitigation scenario of the distribution network. Based on the status of the distribution network node equipment, set up four judgment steps. Determine the scenario or continue judgment based on the judgment value of each step, thus forming two mitigation scenarios.

[0056] In this embodiment, this step further includes:

[0057] S101: Based on distribution network operation information, propose scenario judgment criteria. Distribution network operators have different governance needs under different operational scenarios. Define four judgment steps (or stages): sensitive node access, sensitive node operation type, date characteristics, and intraday time period characteristics. Figure 2 As shown, there are two scenario classification results. Scenario 1 addresses the need to minimize harmonic compensation current; Scenario 2 is applicable to harmonic-sensitive load operation scenarios, addressing the different needs of governance objectives at different nodes.

[0058] S102: First judgment step: Based on the information on the harmonic distortion rate requirements of individual nodes in historical operation data, nodes that have access to equipment with more stringent harmonic requirements are defined as sensitive nodes, and the access judgment value of sensitive nodes is obtained.

[0059] Sensitive node access judgment value The calculation method is as follows:

[0060] (1)

[0061] In the formula, For the firsti The node's sensitivity threshold is used to determine whether it's a normal node or a sensitive node. For the first i The node h The minimum required voltage for subharmonics at this voltage level and for both odd and even orders. For the first i The node h The second harmonic is a limiting voltage set according to equipment requirements at this voltage level and for both odd and even orders. If its value is less than the minimum required limit voltage, it is typically used for connection nodes of laboratory analysis / measurement equipment, ultra-high precision instruments, etc.

[0062] If there exists a first i If the sensitive node access judgment value of a node is 1, it means that a sensitive device has been accessed, and the process continues to the next step; if no sensitive device is found, the judgment result is Scenario 1.

[0063] S103: Second judgment step: Based on the information of whether the sensitive node access device is continuously connected throughout the day in the historical operation data, the judgment value of the sensitive node operation type is obtained.

[0064] Sensitive node operation type judgment value The calculation method is as follows:

[0065] (2)

[0066] In the formula, For the first i Sensitive node operation type judgment value for nodes. This is a flag indicating whether sensitive devices are connected continuously throughout the day. 0 indicates yes, typically for medical equipment, communication / server / data center devices; 1 indicates no, typically for laboratory precision instruments, testing equipment, factory CNC equipment, etc.

[0067] If there exists a first i If the sensitive node operation type judgment value of a node is 0, it means that there are sensitive devices that are continuously connected throughout the day, and the judgment result is Scenario 2; if not, proceed to the next step to continue the judgment.

[0068] S104: Third judgment step: For sensitive devices that are not continuously connected throughout the day, based on the historical operation data of the whole year, the access and operation pattern of a single node sensitive device in the whole year is obtained. The set of operation dates is input to obtain the date feature judgment value.

[0069] Date feature judgment value The calculation method is as follows:

[0070] (3)

[0071] In the formula, For the first i Date feature judgment value of the node, D For the current date, For the first i A set of running dates after node-sensitive devices are connected.

[0072] If there exists a first i If the date feature judgment value of a node is 1, it means that there is a sensitive device in operation on that date, but it is uncertain whether it is in the working period. Then proceed to the next step to continue the judgment; if there is no such device, the judgment result is Scenario 1.

[0073] S105: Fourth judgment step: For sensitive devices that are not continuously connected throughout the day, based on the historical operation data of a single day, the access and operation pattern of a single node sensitive device in a single time period is obtained. The set of operating time periods is input to obtain the characteristic judgment value of the time period within the day.

[0074] (4)

[0075] In the formula, For the first i The intraday time-period characteristic judgment condition score of the node. d This is the current time period (one hour is one time period, and a new judgment is required when entering the next time period). For the first i The set of daily operating time periods after a node-sensitive device is connected.

[0076] If there exists a first i If the intraday time-period characteristic judgment value of each node is 1, it indicates that there is a sensitive device in operation within that date and time period, and the judgment result is Scenario 2; if not, the judgment result is Scenario 1. Simultaneously, the scenario judgment will be updated every hour to accommodate the access and disconnection of sensitive devices.

[0077] Step S2: Based on the results of the above scenario classification, a harmonic compensation method for multi-active power filters based on the least squares approach is adopted to analyze the impact of compensation current on node harmonic voltage distortion. Based on the differentiated governance target selection criterion, corresponding node voltage governance target values ​​are selected according to two different scenarios, yielding the harmonic compensation current results for different scenarios.

[0078] In this embodiment, this step further includes:

[0079] S201: Input basic information about the distribution network, including the network impedance matrix, the number and location of active power filters, voltage detection values, etc., and perform data preprocessing.

[0080] Based on the network impedance matrix information, the number of network nodes is defined as follows: nThe number of active power filters connected is p To form relevant access points n × p The impedance matrix is ​​as follows:

[0081] (5)

[0082] In the formula, This is an impedance matrix, representing the impedance relationship between the active power filter connection node and other nodes. Indicates the first i , j Between nodes h Subharmonic impedance value.

[0083] Based on the voltage detection value information, the values ​​of each point are obtained. h Subharmonic voltage:

[0084] (6)

[0085] In the formula, This is a voltage matrix, representing each node. h Second harmonic voltage value Indicates the first i node h Secondary harmonic voltage value.

[0086] The solution variables are set as follows: The compensation current values ​​output by each active power filter are as follows:

[0087] (7)

[0088] In the formula, This is a current matrix, representing the compensation current value output by each active power filter. Indicates the first j Node injection h The value of the subharmonic compensation current.

[0089] Set target voltage value This represents the expected value of the harmonic voltage after compensation, while the target voltage value is the total network node voltage value before compensation. Impact of injecting compensation current on node voltage The sum of these can be obtained as follows:

[0090] (8)

[0091] In the formula, This is a voltage change matrix, representing the nodes caused by active power filter compensation. h Subharmonic voltage variation.

[0092] Based on the least squares method, with the objective of minimizing the sum of squared errors, the required compensation current value for each active power filter is obtained, i.e., the solution quantity:

[0093] (9)

[0094] In the formula, The compensation current matrix represents the required output of the active power filter. h Secondary compensation current value.

[0095] S202: Based on the two scene categories obtained from the scene classification, select the corresponding two different voltage value targets. The values ​​are selected according to the following rules:

[0096] Scenario 1: Minimizing Harmonic Compensation Current Management. This scenario aims to achieve node harmonic distortion rate compliance by minimizing the output compensation current of the active power filter. The target is the lowest harmonic distortion rate that does not affect the normal operation of the equipment, with a target voltage value... The values ​​need to be set or adjusted by the operations and maintenance personnel according to their operational needs.

[0097] Scenario 2: Harmonic-Sensitive Load Management. This scenario targets distribution networks operating with harmonic-sensitive loads, aiming to reduce the possibility of equipment failure or damage. Sensitive nodes have higher requirements for harmonic distortion rates. Based on the different sensitivities of node equipment to voltage distortion, the corresponding target voltage value matrix is ​​modified accordingly. The values ​​of each element in the equation are shown in equation (11).

[0098] Based on the judgment values ​​obtained from the four steps in the scenario judgment criteria, the target voltage value is modified as follows:

[0099] (10)

[0100] In the formula, For the first i Target voltage value for each node For the first i Sensitive node access judgment value for a node. For the first i Sensitive node operation type judgment value for nodes. For the first i Date feature judgment value of the node, For the first i The intraday time-period characteristic judgment condition score of the node. For the first i The node h The minimum required voltage for subharmonics at this voltage level and for both odd and even orders. For the first i The nodeh The limiting voltage for subharmonics at this voltage level and for odd / even orders is set according to the equipment requirements.

[0101] Step S3: Based on the solution method and differentiated objectives, an adaptive solution adjustment mechanism based on dynamic harmonic changes is proposed. The initial value of the compensation current is solved according to the method described in step S201, so that... T As a variable solution time interval, each time interval after the initial value calculation... T Perform a calculation of the compensation current change value. Set the compensation current fluctuation judgment condition, compare the difference between the current and previous compensation current change values, and dynamically adjust the time interval to adapt to the speed of harmonic changes.

[0102] In this embodiment, the step includes:

[0103] S301: The solution process begins; initial values ​​for the time interval are set and assigned to variables. T In the process, the result is calculated using the method described in S201. Store the compensation current value variable In this context, the initial value of the compensation current is used.

[0104] like Figure 3 As shown, the interval since the last solution is [number] days. T Get the current time after the time limit. t Voltage value detection value If the target voltage value remains unchanged, we can modify equation (8) to obtain:

[0105] (11)

[0106] In the formula, The voltage matrix represents the voltage at... t Voltage value detected at time [time]. Let be the current matrix, representing the active power filter in... t The matrix of compensation current changes at any time.

[0107] The least squares method shown in equation (9) is used to solve the formula, where, with Alternative As a known quantity, the solution quantity obtained after calculation is assigned to Therefore, the compensation current change value of each active power filter is:

[0108] (12)

[0109] In the formula, for The active power filter connected at the point is t The current change value is constantly compensated.

[0110] Call the time interval update module to update the time interval T The obtained compensation current change value is used Update compensation current value variable waiting time interval T Then, repeat the above steps.

[0111] S302: Set the judgment conditions for compensation current fluctuation and propose a time interval update method. For example... Figure 4 As shown, based on the previous N The change in compensation current is used to determine whether the time interval needs to be modified. If the change is significant, the time interval needs to be shortened to accommodate situations where harmonics fluctuate drastically over time; if the change is small, it indicates that the fluctuation is not severe, and the update frequency can be appropriately reduced; when it is in the middle or has not passed... N If there are multiple time intervals, then the original time intervals will remain unchanged.

[0112] First, determine if it has already passed. N The time interval is set. If yes, the process continues; otherwise, the time interval remains unchanged.

[0113] Calculate two key values: current difference and current count value. Current difference for t Time period and before N The sum of the changes in compensation current over each time interval is calculated as follows:

[0114] (13)

[0115] In the formula, For the first k Access after a time interval The compensation current variation value output by the active power filter at the node. N This indicates the number of samples used to determine the change in compensation current.

[0116] Current count value for t Time period and before N The total number of times the change in compensation current exceeds the sum of the changes in compensation current over a given time interval is calculated as follows:

[0117] (14)

[0118] In the formula, For setting h The limit for the change in compensation current for subharmonics is set. If the change in compensation current at a node exceeds this limit, a value of 1 is assigned as a counter; otherwise, the amplitude is 0. This is a magnitude correction factor used to normalize the current count value and the current difference to the same magnitude. The value needs to be set or adjusted by the maintenance personnel according to the maintenance requirements.

[0119] The judgment criterion for compensation current fluctuation is based on the current difference. and count value The composition and calculation formula are as follows:

[0120] (15)

[0121] In the formula, for The weight value within the judgment condition.

[0122] Judgment value for compensation current fluctuation If the value exceeds the limit, it indicates drastic harmonic changes, and the time interval needs to be reduced; conversely, if it is below the limit, no change is needed.

[0123] (16)

[0124] In the formula, T For time intervals, The change per unit time interval This is the upper limit of the current fluctuation judgment value. This is the lower limit value for judging current fluctuations.

[0125] The count of time intervals restarts until it reaches the limit again. N Repeat the above steps for a specified time interval.

[0126] Example 2

[0127] A distribution network voltage harmonic distortion mitigation system based on scenario operation status includes:

[0128] The governance scenario judgment module is configured to judge the governance scenario based on the status of the distribution network node equipment;

[0129] The module for determining the target value of the governance is configured to use a multi-active power filter harmonic compensation method based on the least squares method to analyze the impact of the compensation current on the harmonic voltage distortion of the node. Based on the judgment result of the governance scenario, the corresponding voltage governance target value is selected, and the harmonic compensation current result under the corresponding governance scenario is obtained.

[0130] The adaptive solution module is configured to solve the voltage control target value based on the harmonic compensation current result. During the solution process, an adaptive solution adjustment mechanism based on the dynamic change of harmonics is introduced. According to the preset compensation current fluctuation judgment condition, the difference between the current and previous compensation current change values ​​is compared. Based on the difference, the time interval of solving the compensation current change value is dynamically adjusted to adapt to the harmonic change speed.

[0131] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can be implemented in one or more computer-usable storage media (including, but not limited to, disk storage, etc.) containing computer-usable program code. CD - ROM It takes the form of a computer program product implemented on (such as optical memory, etc.).

[0132] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0133] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0134] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0135] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art without creative effort within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A power distribution network voltage harmonic distortion management method based on scene operating state, characterized in that, Includes the following steps: The governance scenario is determined based on the status of the equipment at the distribution network nodes; A harmonic compensation method based on the least squares method for multi-active power filters is adopted to analyze the impact of compensation current on node harmonic voltage distortion. Based on the judgment results of the governance scenario, the corresponding voltage governance target value is selected, and the harmonic compensation current result under the corresponding governance scenario is obtained. Based on the harmonic compensation current results, the voltage control target value is calculated. During the calculation process, an adaptive calculation adjustment mechanism based on the dynamic changes of harmonics is introduced. According to the preset compensation current fluctuation judgment conditions, the difference between the current and previous compensation current change values ​​is compared. Based on the difference, the time interval for solving the compensation current change value is dynamically adjusted to adapt to the harmonic change speed. The process of determining the governance scenario based on the status of distribution network node equipment includes: judging from four aspects in sequence based on the status of distribution network node equipment, including sensitive node access, sensitive node operation type, date characteristics, and intraday time period characteristics. There are two governance scenarios: Scenario 1 addresses the need to minimize harmonic compensation current; Scenario 2 is applicable to harmonic sensitive load operation scenarios and addresses the different needs of governance objectives for different nodes. According to the judgment result of the governance scene, the process of selecting the corresponding voltage governance target value includes: scene one is the minimum harmonic compensation current governance scene, to minimize the active power filter output compensation current, to realize the node harmonic distortion rate standard, to the lowest harmonic distortion rate which does not affect the normal operation of the equipment as the target, the target voltage value The value is set or adjusted according to operation and maintenance requirements; Scenario 2 is a harmonic-sensitive load management scenario, targeting distribution networks operating with harmonic-sensitive loads. Based on the varying sensitivities of node equipment to voltage distortion, target voltage values ​​are set. The values ​​of each element in the code are revised. Based on the harmonic compensation current result, according to the voltage management target value, the solving process includes: setting the initial value of the time interval, taking the harmonic compensation current result as the initial value of the compensation current value, obtaining the voltage value detection value of the current time t , the target voltage value remains unchanged, and the least square method is solved in the form of solving . Update the compensation current value variable by updating the compensation current value variable with the obtained compensation current change value after the time interval T, and repeat the above steps after waiting for the time interval T.

2. The power distribution network voltage harmonic distortion treatment method based on the scene operation state according to claim 1, characterized in that, The process of determining the governance scenario based on the status of distribution network node equipment includes: defining nodes with more stringent harmonic distortion rate requirements as sensitive nodes based on historical operational data for individual nodes, obtaining the sensitive node access judgment value, and if the first node has such a value, then the process continues. i If the sensitive node access judgment value of a node is the first target value, it indicates that a sensitive device has been accessed, and the process proceeds to the next step to continue judgment; if no sensitive device is found, the judgment result is Scenario 1. Based on historical operational data regarding whether sensitive node access devices are continuously connected throughout the day, a sensitive node operation type judgment value is obtained. If the first... i If the sensitive node operation type judgment value of each node is the second target value, it indicates that there are sensitive devices that are continuously connected throughout the day, and the judgment result is scenario two; if not, proceed to the next step to continue the judgment. Based on historical operational data throughout the year, patterns in the access and operation of sensitive devices at individual nodes are identified. Based on the set of operational dates, date characteristic judgment values ​​are derived. If a certain value exists... i If the date feature judgment value of a node is the first target value, it indicates that there is a sensitive device in operation on that date, but it is uncertain whether it is in the working period. If so, proceed to the next step to continue the judgment; if not, the judgment result is Scenario 1. Based on historical daily operational data, the patterns of access and operation of sensitive devices on individual nodes within a single day's time period are obtained. Based on the set of operational time periods, characteristic judgment values ​​for each time period within the day are derived. If a certain value exists... i If the intraday time period characteristic judgment value of a node is the first target value, it indicates that there is a sensitive device in working state within that date and time period, and the judgment result is Scenario 2; if it does not exist, the judgment result is Scenario 1.

3. The power distribution network voltage harmonic distortion management method based on the scene operation state according to claim 1, characterized in that, The process of analyzing the impact of compensation current on node harmonic voltage distortion using a multi-active power filter harmonic compensation method based on the least squares method includes: acquiring basic information of the distribution network, including the network impedance matrix, the number and location of active power filters connected and voltage detection values, and performing data preprocessing; Based on the network impedance matrix information, the number of network nodes is defined as follows: n The number of active power filters connected is p To form relevant access points n × p The impedance matrix is ​​calculated based on the voltage detection values ​​at each point. h For subharmonic voltage, set the solution variables, calculate the compensation current values ​​of each active power filter output, and set the target voltage value. This represents the expected value of the harmonic voltage after compensation, while the target voltage value is the total network node voltage value before compensation. Impact of injected compensation current on node voltage sum; Based on the least squares method, with the goal of minimizing the sum of squared errors, the required compensation current value for each active power filter is calculated, i.e., the solution quantity.

4. The method for mitigating voltage harmonic distortion in a distribution network based on scenario operating states as described in claim 1, characterized in that, target voltage value The process of revising the values of the elements in the target voltage value includes: ； In the formula, For the first i Target voltage value for each node For the first i Sensitive node access judgment value for a node. For the first i Sensitive node operation type judgment value for nodes. For the first i Date feature judgment value of the node, For the first i The intraday time-period characteristic judgment condition score of the node. For the first i The node h The minimum required voltage for subharmonics at this voltage level and for both odd and even orders. For the first i The node h The limiting voltage for subharmonics at this voltage level and for odd / even orders is set according to the equipment requirements.

5. The power distribution network voltage harmonic distortion management method based on the scene operating state according to claim 1, characterized in that, The criteria for judging compensation current fluctuations include: determining whether a fluctuation has already occurred. N If the time interval is specified, continue the evaluation; otherwise, keep the time interval unchanged. Determine the magnitude of the compensation current fluctuation judgment value. If it exceeds the limit, it indicates that the harmonic changes are drastic. Adjust the time interval. If it is between the upper and lower limits, no change is needed. The number of time intervals is restarted counting until the number of time intervals is reached again. N time intervals.

6. The power distribution network voltage harmonic distortion management method based on the scenario operating state according to claim 5, characterized in that, The calculation process for the compensation current fluctuation judgment value includes: calculating two key values: the current difference and the current count value. for t Time period and before N The sum of the compensation current changes over each time interval; current count value for t Time period and before N The total number of times the change in compensation current exceeds the total change in compensation current within a time interval; The compensation current fluctuation determination condition is constituted by a current difference value and a count value weighted The process of determining the magnitude of the compensation current fluctuation judgment value includes: ； In the formula, T is a time interval, is a time interval unit change amount, is an upper limit value of the current fluctuation determination value, is a lower limit value of the current fluctuation determination value.

7. A power distribution network voltage harmonic distortion management system based on the scenario operating state, applying the method of claim 1, characterized in that, include: The governance scenario judgment module is configured to judge the governance scenario based on the status of the distribution network node equipment; The module for determining the target value of the governance is configured to use a multi-active power filter harmonic compensation method based on the least squares method to analyze the impact of the compensation current on the harmonic voltage distortion of the node. Based on the judgment result of the governance scenario, the corresponding voltage governance target value is selected, and the harmonic compensation current result under the corresponding governance scenario is obtained. The adaptive solution module is configured to solve the voltage control target value based on the harmonic compensation current result. During the solution process, an adaptive solution adjustment mechanism based on the dynamic change of harmonics is introduced. According to the preset compensation current fluctuation judgment condition, the difference between the current and previous compensation current change values ​​is compared. Based on the difference, the time interval of solving the compensation current change value is dynamically adjusted to adapt to the harmonic change speed.

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