A method for multi-stage delay voltage regulation with load regulation considering photovoltaic output timing characteristics

Abstract

This invention discloses a multi-level delayed voltage regulation method for on-load tap changer that considers the timing characteristics of photovoltaic output in the field of power system automation and distribution network operation control technology. The method includes: generating a regulation delay time corresponding to the current operating state based on voltage fluctuation levels, candidate time sequence stages, and a pre-constructed set of operating constraints; adjudicating the action priority based on the regulation delay time and pre-set action priority rules, according to feasibility criteria for different regulation actions, thereby pre-defining the feasible operating state space of the on-load tap changer during daily operation; and scheduling the regulation behavior of the reactive power regulating device during daily operation in a time-segmented manner based on reactive power output optimization and switching control results and the pre-definition of the feasible operating state space. This invention can solve the technical problem that existing on-load tap changer methods are unable to effectively suppress ineffective or repetitive voltage regulation actions, affecting equipment lifespan.

Description

Technical Field

[0001] This invention relates to the field of power system automation and distribution network operation control technology, and in particular to an on-load tap changer with multi-stage delay considering the timing characteristics of photovoltaic output. Background Technology

[0002] With the rapid development of distributed renewable energy, especially distributed photovoltaic (PV) power generation, in distribution networks, low-voltage distribution networks have gradually evolved from traditional unidirectional power supply structures to active distribution networks with multiple power sources. PV power sources are typically connected at the user side or transformer substation side, and their output exhibits significant intermittency, fluctuation, and intraday timing characteristics. While improving the absorption of renewable energy, this also places higher demands on the stable operation of the distribution network voltage.

[0003] In scenarios with high photovoltaic (PV) integration, low-voltage distribution networks often experience a surge in voltage across transformer substations and voltage exceeding the upper limit during the day due to concentrated PV output, while voltage drops during the morning, evening, or night due to decreased PV output. This frequent and significant voltage fluctuation makes traditional voltage regulation methods relying on static parameters inadequate for these operational characteristics. Existing technologies typically use the substation bus voltage or the voltage at the end of the transformer as feedback, achieving automatic voltage regulation by setting target voltage values, allowable deviation ranges, and action delays. Related research and engineering practice show that on-load tap-changing technology has good regulation effects in traditional load-dominated distribution networks and has been applied in various distribution automation systems and smart distribution transformers. Some existing technologies also introduce fixed dead-zone control, single delay criteria, or simple voltage upper and lower limit triggering mechanisms to avoid frequent operation of the voltage regulating device.

[0004] Under operating conditions with a high proportion of photovoltaic power generation and frequent power output fluctuations, existing on-load tap changer control methods generally have the following shortcomings:

[0005] Lack of consideration for the timing characteristics of photovoltaic power output;

[0006] Existing voltage regulation strategies mostly make adjustment decisions based on instantaneous or short-term voltage deviations, failing to fully utilize the predictable trend of photovoltaic output changes within a day, resulting in delayed voltage regulation actions;

[0007] The delay criterion is singular, making it difficult to distinguish voltage fluctuations of different amplitudes;

[0008] The fixed delay method cannot effectively distinguish between short-term small fluctuations caused by cloud shadows and continuous voltage deviations caused by significant changes in photovoltaic output. It is prone to voltage regulation lag or ineffective action when photovoltaic fluctuations are frequent.

[0009] The voltage regulation action is not matched with the fluctuation intensity;

[0010] In existing technologies, the voltage regulation step size and triggering conditions are usually set in a fixed manner, without graded control according to the degree of voltage change or the level of output change, which can easily lead to insufficient voltage regulation or over-regulation.

[0011] In scenarios where photovoltaic power output fluctuates frequently, existing control strategies are unable to effectively suppress ineffective or repetitive voltage regulation actions, leading to an increase in the number of tap changer operations and on-load tap changer operations, which affects equipment lifespan and is detrimental to long-term reliable operation of the equipment.

[0012] Therefore, there is an urgent need for an on-load voltage regulation method that can fully consider the intraday time sequence characteristics of photovoltaic power output, distinguish different power output change levels, and achieve differentiated voltage regulation control through a multi-level delay mechanism, so as to reduce the frequency of voltage regulation and improve the operational reliability and adaptability of distribution transformers while ensuring voltage quality. Summary of the Invention

[0013] The purpose of this invention is to overcome the shortcomings of the prior art and provide an on-load tap changer with multi-stage delay that takes into account the timing characteristics of photovoltaic output. This method can solve the technical problem that existing on-load tap changer methods are unable to effectively suppress ineffective or repeated tap changer actions, which affects the lifespan of the equipment.

[0014] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0015] In a first aspect, the present invention provides an on-load tap-changing multi-stage delayed voltage regulation method that considers the timing characteristics of photovoltaic power output, comprising:

[0016] Obtain the photovoltaic power output time series and short-time power output series of the photovoltaic power source in the distribution area;

[0017] The photovoltaic power output time series is preprocessed, decomposed into multiple time scales, extracted into time series feature parameters, and detected stage change points in sequence to divide the photovoltaic power output time series into different candidate time series stages.

[0018] Based on the extracted time-series feature parameters, the voltage is divided into different fluctuation levels;

[0019] Based on the voltage fluctuation level, candidate time sequence stage, and pre-built set of operating constraints, an adjustment delay time corresponding to the current operating state is generated;

[0020] Based on the adjustment delay time and the pre-set action priority adjudication rules, the action priority is adjudicated according to the feasibility criteria of different adjustment actions, thereby pre-limiting the feasible operating state space of the on-load tap changer during the daytime operation.

[0021] Based on the aforementioned short-time output sequence, the local change trend at the current moment is estimated using the linear least squares method to obtain the current short-term output change rate;

[0022] Apply stage constraints to the trend slope based on the current short-term output change rate and the pre-acquired current time series stage label, and obtain the constraint slope;

[0023] Predicted power output of photovoltaic systems within a day is obtained based on the constrained slope.

[0024] Based on the predicted output of photovoltaic power during the day and the pre-constructed VQ droop control curve, the reactive power regulation device is optimized and its switching is controlled.

[0025] Based on the results of reactive power output optimization and switching control, and the pre-definition of the feasible operating state space of the on-load tap changer during the daytime operation, the adjustment behavior of the reactive power regulation device during the daytime operation is arranged in a time-based manner to suppress the participation of the on-load tap changer in regulation.

[0026] Furthermore, the photovoltaic power output time series is preprocessed, decomposed into multiple time scales, and its time series feature parameters are extracted and stage change points are detected sequentially. This divides the photovoltaic power output time series into different candidate time series stages, including:

[0027] The photovoltaic power output time series is normalized to obtain a normalized photovoltaic power output time series.

[0028] Anomaly removal is performed on the normalized photovoltaic power output time series to obtain the anomaly-removed photovoltaic power output time series;

[0029] The photovoltaic power output time series after anomaly removal is smoothed to obtain the smoothed photovoltaic power output time series.

[0030] The smoothed photovoltaic power output time series is decomposed into multiple time scales to obtain the trend component reflecting the intraday change trend and the fluctuation component reflecting the short-term fluctuation characteristics.

[0031] Based on the trend component and fluctuation component, time series feature parameters are extracted, including trend slope, short-term ramp rate, fluctuation intensity and fluctuation frequency.

[0032] The quantity to be monitored is constructed based on the time series feature parameters, wherein the quantity to be monitored is at least one of the time series feature parameters;

[0033] Based on the monitored quantity, a forward cumulative sum and a reverse cumulative sum are constructed, and the expressions include:

[0034] ;

[0035] ;

[0036] ;

[0037] in, For positive cumulative sum, For reverse cumulative sum, For the quantity to be monitored, The baseline mean This is the drift parameter, used to suppress small random disturbances in the offset. The standard deviation of the monitored quantity during the stable phase. The standard coefficient is preferably taken as 0.1 to 0.3.

[0038] like ,determination To identify candidate moments for stage change, the photovoltaic power output time series is divided into different candidate moment time series stages.

[0039] Furthermore, classifying the voltage into different fluctuation levels based on the extracted time-series feature parameters includes:

[0040] Based on the extracted time-series feature parameters, a comprehensive fluctuation intensity index is calculated, the expression of which includes:

[0041] ;

[0042] in, As the first weight, As the second weight, As the third weight, As a comprehensive index of volatility intensity, This is the number of sampling points within the preset statistical time window;

[0043] Volatility levels are classified according to a comprehensive volatility intensity index:

[0044] when The fluctuation level is small fluctuation;

[0045] when The fluctuation level is medium fluctuation;

[0046] when The fluctuation level is large fluctuation;

[0047] in, This is the lower limit of the short-time rate of change parameter. This represents the upper limit of the short-time rate of change parameter.

[0048] Furthermore, based on the voltage fluctuation level, the candidate time series stage, and the pre-built set of operating constraints, a regulation delay time corresponding to the current operating state is generated, the expression of which includes:

[0049] ;

[0050] in, This indicates the candidate timing phase for photovoltaic power output. Indicates the voltage fluctuation level. Indicates the set of constraints to be executed. This indicates the adjustment delay time corresponding to the current operating state;

[0051] The specific steps include:

[0052] Set the base delay time according to the voltage fluctuation level;

[0053] The base delay time is corrected based on the candidate timing phase of photovoltaic power output to obtain the corrected delay time;

[0054] The modified delay time is trimmed or adjusted according to the set of operating constraints to obtain the adjusted delay time;

[0055] It also includes a hierarchical setting principle for multi-level delays. The hierarchical setting principle for multi-level delays includes at least two or more different delay parameter groups, and different delay levels meet the following setting principles:

[0056] Setting 1: When the photovoltaic output is in the disturbance segment of the aforementioned timing stage identification results, and the voltage fluctuation level is within the small fluctuation level range, a first-level delay time is generated. The first level of delay time is used to suppress adjustment actions caused by small fluctuations within a short time scale;

[0057] Setting 2: When the photovoltaic output is in the ramp-up or pullback phase of the aforementioned timing stage identification results, and the voltage fluctuation level is in the large fluctuation range, a second-level delay time is generated. The second-level delay time is used to intervene and adjust in a timely manner when the voltage continues to deviate from a clear trend. The first-level delay time... Greater than the second level delay time ;

[0058] Setting 3: When the set of operating constraints indicates that the current reactive power regulation margin is sufficient, i.e., the reactive power regulation capacity has not reached the capacity boundary and the rate of change meets the requirements, the generated delay time is corrected in the extension direction to obtain the corrected delay time:

[0059] ;

[0060] in, To correct the delay time, The positive delay correction amount is used to further suppress unnecessary adjustment actions;

[0061] Setting 4: When the set of operating constraints indicates that the current reactive power regulation capacity is close to the capacity limit, the rate of change is limited, or the number of regulation times is close to the preset limit, the generated delay time is corrected in the direction of shortening to obtain the corrected delay time:

[0062] ;

[0063] in, This is the reverse delay correction amount, and it is a positive number.

[0064] Furthermore, based on the adjustment delay time and pre-set action priority adjudication rules, and according to the feasibility criteria of different adjustment actions, the action priority is adjudicated to achieve the pre-definition of the feasible operating state space of the on-load tap changer during daytime operation, including:

[0065] For different types of reactive power regulation and on-load tap changer actions, feasibility criteria are constructed for their respective current operating conditions. For any regulation action 'a', its feasibility function is defined as:

[0066] ;

[0067] When the function meets the preset conditions, it is determined that the adjustment action is feasible to be triggered in the current operating state:

[0068] For reactive power regulation actions, if the user can participate in the regulation within the operating constraints, it is determined that the action is feasible.

[0069] For on-load voltage regulation, when the corresponding level of regulation delay time is reached and the operating constraints allow its operation, it is determined that the triggering is feasible.

[0070] The rules for determining the priority of actions include:

[0071] When reactive power regulation is feasible to be triggered, but on-load tap changer is not feasible to be triggered, only reactive power regulation is allowed.

[0072] When both reactive power regulation and on-load tap changer actions are feasible to trigger, reactive power regulation actions shall be given priority.

[0073] When reactive power regulation is not feasible to trigger, but on-load tap changer is feasible to trigger, on-load tap changer is permitted.

[0074] When neither of the two types of adjustment actions is feasible to trigger, the current operating state is maintained.

[0075] Furthermore, it also includes:

[0076] In the current iterative optimization control layer, feedback information of the running results is introduced to dynamically correct the optimization objective function and its weights, so that the generated running plan can gradually conform to the actual running state and avoid deviation of the adjustment effect due to model uncertainty, prediction bias or changes in the running environment.

[0077] The feedback information includes:

[0078] Voltage deviation at each key node during actual operation;

[0079] The actual number of times, timing of, and amplitude of action of the on-load tap changer;

[0080] The actual output and saturation state of the reactive power regulating device;

[0081] The deviation between the predicted and actual photovoltaic power output;

[0082] Evaluation results of the effectiveness of adjustment actions in the previous operating cycle.

[0083] Furthermore, based on the short-time output sequence, the local trend of change at the current moment is estimated using the linear least squares method to obtain the current short-term output change rate, the expression of which includes:

[0084] ;

[0085] in, This represents the current short-term rate of change in output. Within the sliding window Photovoltaic power output time series at any given moment It is a short-time output sequence. Let be the slope parameter of the linear trend to be estimated. The time index variable within the sliding window. The intercept parameter is the linear fitting model.

[0086] Furthermore, based on the current short-term output change rate and the pre-acquired current time-series stage label, a stage constraint is applied to the trend slope to obtain the constraint slope, the expression of which includes:

[0087] ;

[0088] in, To constrain the slope, () is the amplitude limiting function. This is the label for the current time series stage. The minimum trend slope under the current time series label. The maximum trend slope under the current time series stage label;

[0089] The predicted power output of photovoltaic systems during the day is obtained based on the constrained slope. The expression includes:

[0090] ;

[0091] in, To predict the output, The sampling period is The preferred time is 15 minutes. This is a time series of photovoltaic power output.

[0092] Furthermore, the pre-constructed VQ droop control curve includes:

[0093] Voltage dead zone width Used to define the voltage range in which reactive power regulation does not operate;

[0094] droop slope It is used to characterize the proportional relationship between voltage deviation and reactive power output;

[0095] Maximum reactive power output ratio coefficient This is used to limit the effective utilization of reactive power output during the current operating phase;

[0096] Adjusting the output of the reactive power regulating device includes:

[0097] When the current timing stage label is low output stage, set the first voltage dead zone width. Set the first downward slope And limit the reactive power output ratio to the first ratio range. ;

[0098] When the current timing phase label is a disturbance phase, set the second voltage dead zone width. Set the second downward slope And limit the reactive power output ratio to the second ratio range. ;

[0099] When the current timing phase label is ramp-up phase, set the third voltage dead zone width. Set the third downward slope And limit the reactive power output ratio to the third ratio range. ;

[0100] When the current timing phase label is the fallback phase, the voltage dead zone width is gradually restored from the third voltage dead zone width to the second voltage dead zone width, and the droop slope is adjusted to the second droop slope.

[0101] When the current timing stage label is the plateau stage, set the second voltage dead zone width. Set a standard droop slope to maintain a normal reactive power output ratio;

[0102] in, , .

[0103] Secondly, the present invention provides an on-load tap changer with multi-stage delay voltage regulation that considers the timing characteristics of photovoltaic power output, comprising:

[0104] The sequence acquisition module is used to acquire the photovoltaic power output time series and short-time power output series of photovoltaic power sources in the distribution area;

[0105] The sequence processing module is used to perform preprocessing, multi-timescale decomposition, time series feature parameter extraction and stage change point detection on the photovoltaic power output time series in sequence, and divide the photovoltaic power output time series into different candidate time series stages.

[0106] A fluctuation level classification module is used to classify voltage into different fluctuation levels based on the extracted time-series feature parameters;

[0107] The adjustment delay time generation module is used to generate an adjustment delay time corresponding to the current operating state based on the voltage fluctuation level, the candidate time sequence stage, and the pre-built set of operating constraints.

[0108] The pre-defined module is used to determine the action priority based on the adjustment delay time and the pre-set action priority rules, and to make a decision on the action priority according to the feasibility criteria of different adjustment actions, so as to pre-define the feasible operating state space of the on-load tap changer during the daytime operation.

[0109] The local change trend estimation module is used to estimate the local change trend at the current moment based on the short-term output sequence using the linear least squares method, and obtain the current short-term output change rate.

[0110] The slope constraint module is used to apply stage constraints to the trend slope based on the current short-term output change rate and the pre-acquired current time series stage label, and obtain the constraint slope.

[0111] The predicted output acquisition module is used to obtain the predicted output of photovoltaic power within the day based on the constraint slope;

[0112] The reactive power output optimization and switching control module is used to optimize and control the reactive power regulation device based on the predicted output of photovoltaic power during the day and the pre-constructed VQ droop control curve.

[0113] The suppression and regulation module is used to schedule the regulation behavior of the reactive power regulation device during the daytime operation based on the results of reactive power output optimization and switching control and the pre-limitation of the feasible operating state space of the on-load tap changer during the daytime operation, so as to suppress the participation of the on-load tap changer in regulation.

[0114] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0115] This invention first proposes a multi-level delayed voltage regulation method for on-load tap changers that considers the timing characteristics of photovoltaic power output. It generates a regulation delay time corresponding to the current operating state based on voltage fluctuation levels, candidate timing stages, and a pre-constructed set of operating constraints. Then, based on the regulation delay time and pre-set action priority adjudication rules, it adjudicates the action priority according to the feasibility criteria of different regulation actions, thereby pre-limiting the feasible operating state space of the on-load tap changer during the daytime operation. Finally, based on the reactive power output optimization and switching control results and the pre-limited feasible operating state space of the on-load tap changer during the daytime operation, it schedules the regulation behavior of the reactive power regulating device in a time-based manner, suppressing the participation of the on-load tap changer in regulation. This method can distinguish different output change levels and achieve differentiated voltage regulation control through a multi-level delay mechanism, thereby reducing the frequency of voltage regulation while ensuring voltage quality and improving the operational reliability and adaptability of the distribution transformer. Attached Figure Description

[0116] Figure 1 This is a flowchart of an on-load tap changer with multi-stage delay voltage regulation method that considers the timing characteristics of photovoltaic power output, provided by an embodiment of the present invention;

[0117] Figure 2 This is a schematic diagram of a multi-stage delayed voltage regulation method for on-load tap change that takes into account the timing characteristics of photovoltaic power output, provided in an embodiment of the present invention. Detailed Implementation

[0118] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0119] In this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B together, or B alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0120] Example 1:

[0121] Figure 1This is a flowchart of the on-load tap-changing multi-stage delayed voltage regulation method considering the timing characteristics of photovoltaic output, as described in Embodiment 1 of the present invention. The on-load tap-changing multi-stage delayed voltage regulation method considering the timing characteristics of photovoltaic output provided in this embodiment can be applied to a terminal and can be executed by a mechanical equipment fault identification device. This device can be implemented in software and / or hardware and can be integrated into the terminal, such as any smartphone, tablet, or computer device with communication capabilities. Figure 1 and Figure 2 As shown, the method in this embodiment specifically includes the following steps:

[0122] Step 1: Obtain the output data of photovoltaic power sources in the distribution area, and form photovoltaic output time series and short-time output series based on the output data;

[0123] Step Two: The photovoltaic power output time series is preprocessed, decomposed into multiple timescales, and its time-series feature parameters are extracted and stage change points are detected sequentially. The photovoltaic power output time series is divided into different candidate time-series stages representing the transition from one operating state to another during the day's operation. Stage labels corresponding to these candidate time-series stages are output, including:

[0124] The photovoltaic power output time series is normalized to obtain a normalized photovoltaic power output time series, the expression of which includes:

[0125] ;

[0126] in, For photovoltaic power output time series, This is the normalized photovoltaic power output time series. The total installed capacity of photovoltaic power generation or the rated power of inverters in the distribution area;

[0127] Anomaly removal is performed on the normalized photovoltaic power output time series to obtain the anomaly-removed photovoltaic power output time series, the expression of which includes:

[0128] ;

[0129] ;

[0130] ;

[0131] ;

[0132] ;

[0133] when To avoid division by zero or threshold invalidation, let:

[0134] ;

[0135] in, For the current moment, The photovoltaic power output time series after anomaly removal, The window value is the median. This represents the absolute deviation of the median. () indicates the operation of taking the median of a sample set. The time index variable within the sliding window. The preset minimum positive threshold, This is the anomaly detection coefficient, used to control the sensitivity of anomaly data identification based on the absolute deviation of the median. The preferred value range is 3 to 6. This represents the set of time indices used in statistical calculations. The window duration. The sampling period is The optimal number of sampling points within the window. Take 1 min to 10 min;

[0136] The photovoltaic power output time series after anomaly removal is smoothed to obtain the smoothed photovoltaic power output time series, the expression of which includes:

[0137] ;

[0138] in, The smoothed photovoltaic power output time series, For a smooth window length (in terms of the number of sampling points), 5s to 120s is preferred. for, The summation index variable represents the index of the first element within the window. One historical sampling point;

[0139] The smoothed photovoltaic power output time series is decomposed into multiple time scales to obtain the trend component reflecting intraday variation and the fluctuation component reflecting short-term volatility characteristics. The expressions include:

[0140] ;

[0141] ;

[0142] in, As a trend component, The length of the long window (in terms of the number of sampling points) is used to extract the trend component, preferably 1 hour. For fluctuation components;

[0143] Based on the trend component and fluctuation component, time series feature parameters are extracted, including trend slope, short-term ramp rate, fluctuation intensity and fluctuation frequency.

[0144] The monitored quantity is constructed based on the time series characteristic parameters. The monitored quantity is at least one of the time series characteristic parameters, preferably the trend slope, short-term ramp rate or fluctuation intensity, or a weighted combination of the above parameters.

[0145] Based on the monitored quantity, a forward cumulative sum and a reverse cumulative sum are constructed, and the expressions include:

[0146] ;

[0147] ;

[0148] ;

[0149] in, For positive cumulative sum, For reverse cumulative sum, For the quantity to be monitored, This is the baseline mean (which can be obtained from the early stable period of the day). This is the drift parameter, used to suppress small random disturbances in the offset. The standard deviation of the monitored quantity during the stable phase. The standard coefficient is preferably taken as 0.1 to 0.3.

[0150] like ,in, The preset judgment threshold is preferably on the order of magnitude corresponding to 3 to 10 times the noise standard deviation; To suppress false alarms due to small drift, a value of 0.1 is preferred. ~0.3 ;determination To identify candidate moments for phase change, the photovoltaic power output time series is divided into different candidate moment time series stages, and the stage labels corresponding to the candidate moment time series stages are output:

[0151] When all M consecutive samples satisfy If the trend component is less than the preset low output threshold, output a low output / nighttime segment label;

[0152] When all M consecutive samples satisfy or If the fluctuation intensity is greater than the preset fluctuation threshold or the fluctuation frequency is less than the preset frequency threshold, output the disturbance segment (cloud shadow fluctuation) label;

[0153] When all M consecutive samples satisfy And it does not belong to the disturbance section, so output the climbing section label;

[0154] When all M consecutive samples satisfy And it does not belong to the disturbance segment, so output the fallback segment label;

[0155] When all M consecutive samples satisfy and Output platform segment tags;

[0156] in, For low output threshold, The slope threshold, For fluctuation threshold, As a frequency threshold, M is preferably 3 to 10. As a trend component, For fluctuation intensity, For the frequency of fluctuation, The slope represents the trend.

[0157] Step 3: Based on the extracted time-series feature parameters, the voltage is divided into different fluctuation levels, including:

[0158] Based on the extracted time-series feature parameters, a comprehensive fluctuation intensity index is calculated, the expression of which includes:

[0159] ;

[0160] in, As the first weight, As the second weight, As the third weight, As a comprehensive index of volatility intensity, This is the number of sampling points within the preset statistical time window;

[0161] Volatility levels are classified according to a comprehensive volatility intensity index:

[0162] when The fluctuation level is small fluctuation;

[0163] when The fluctuation level is medium fluctuation;

[0164] when The fluctuation level is large fluctuation;

[0165] in, This is the lower limit of the short-time rate of change parameter. This represents the upper limit of the short-time rate of change parameter.

[0166] Step 4: Based on the voltage fluctuation level, candidate time series stage, and pre-built set of operating constraints, generate the adjustment delay time corresponding to the current operating state, including:

[0167] Based on the voltage fluctuation level, candidate time series stage, and pre-built set of operating constraints, an adjustment delay time corresponding to the current operating state is generated, and the expression includes:

[0168]

[0169] in, This indicates the candidate timing phase for photovoltaic power output. Indicates the voltage fluctuation level. Indicates the set of constraints to be executed. This indicates the adjustment delay time corresponding to the current operating state;

[0170] The specific steps include:

[0171] Set the base delay time according to the voltage fluctuation level;

[0172] The base delay time is corrected based on the candidate timing phase of photovoltaic power output to obtain the corrected delay time;

[0173] The modified delay time is trimmed or adjusted according to the set of operating constraints to obtain the adjusted delay time;

[0174] It also includes a hierarchical setting principle for multi-level delays. The hierarchical setting principle for multi-level delays includes at least two or more different delay parameter groups, and different delay levels meet the following setting principles:

[0175] Setting 1: When the photovoltaic output is in the disturbance segment of the aforementioned timing stage identification results, and the voltage fluctuation level is within the small fluctuation level range, a first-level delay time is generated. The first level delay time takes a relatively large value range among all level delay times, which is used to suppress the adjustment action caused by small fluctuations in a short time scale;

[0176] Setting 2: When the photovoltaic output is in the ramp-up or pullback phase of the aforementioned timing stage identification results, and the voltage fluctuation level is in the large fluctuation range, a second-level delay time is generated. The second-level delay time takes a relatively small range among all level delay times, and is used to intervene and adjust in a timely manner when the voltage continues to deviate from the trend clearly.

[0177] Setting 3: When the set of operating constraints indicates that the current reactive power regulation margin is sufficient, i.e., the reactive power regulation capacity has not reached the capacity boundary and the rate of change meets the requirements, the generated delay time is corrected in the extension direction to obtain the corrected delay time:

[0178]

[0179] in, To correct the delay time, The positive delay correction amount is used to further suppress unnecessary adjustment actions;

[0180] Setting 4: When the set of operating constraints indicates that the current reactive power regulation capacity is close to the capacity limit, the rate of change is limited, or the number of regulation times is close to the preset limit, the generated delay time is corrected in the direction of shortening to obtain the corrected delay time:

[0181]

[0182] in, This is the reverse delay correction amount, and it is a positive number.

[0183] The set of operational constraints includes:

[0184] Voltage operation constraints: To ensure that the voltage of each key node within the transformer substation is within the allowable range, constraints are established on the voltage operation status, including the predicted voltage values ​​of the substation busbar, voltage-sensitive nodes, or terminal nodes. Apply the following constraints:

[0185] ;

[0186] in, and These are the lower and upper voltage limits, which can be set based on power grid operation standards or engineering experience.

[0187] On-load tap changing operation constraints: Based on the operating characteristics of the tap changer of an on-load tap changing transformer, constraints are established on the range of tap positions. It must be limited to the range of gears allowed by the device. The expression includes:

[0188] ;

[0189] in, and Indicates the minimum and maximum tap positions.

[0190] Single voltage regulation amplitude constraint: To avoid voltage surges or equipment impact caused by excessively large voltage range jumps, the amplitude of a single voltage regulation action is limited. The expression includes:

[0191] ;

[0192] in, This represents the maximum allowable gear shift in a single operation.

[0193] To reflect the mechanical lifespan limitation of the tap changer, a constraint is established on the number of voltage regulation operations. The expression includes:

[0194] ;

[0195] in, This represents the maximum number of voltage regulation actions allowed within a preset time scale.

[0196] Modeling operational constraints for reactive power regulation devices: Establishing constraints reflecting the capacity and response capability of reactive power regulation devices involved in voltage regulation.

[0197] Reactive power output capacity constraint: The reactive power output of the reactive power regulating device should meet its rated capacity limit, expressed as follows:

[0198] ;

[0199] in, and Do not define the lower and upper limits of reactive power output.

[0200] Reactive power rate constraint: To avoid drastic voltage changes caused by reactive power regulation, a constraint is imposed on the rate of change of reactive power output. The expression includes:

[0201] ;

[0202] in, This represents the upper limit of the rate of change of reactive power.

[0203] Discrete reactive power switching constraints: When the reactive power regulation device is a discrete switching device, its switching state... Discrete value constraints must be met, and the expressions include:

[0204] .

[0205] Step 5: Based on the adjustment delay time and pre-set action priority adjudication rules, and according to the feasibility criteria of different adjustment actions, the action priority is adjudicated to pre-limit the feasible operating state space of the on-load tap changer during intraday operation. This reduces the degree of freedom of the on-load tap changer during real-time control and avoids its frequent participation in regulation under short-term fluctuation conditions. This includes:

[0206] Based on the adjustment delay time and pre-set action priority adjudication rules, and according to the feasibility criteria of different adjustment actions, the action priority is adjudicated to achieve the pre-definition of the feasible operating state space of the on-load tap changer during daytime operation, including:

[0207] For different types of reactive power regulation and on-load tap changer actions, feasibility criteria are constructed for their respective current operating conditions. For any regulation action 'a', its feasibility function is defined as:

[0208] ;

[0209] When the function meets the preset conditions, it is determined that the adjustment action is feasible to be triggered in the current operating state:

[0210] For reactive power regulation actions, if the user can participate in the regulation within the operating constraints, it is determined that the action is feasible.

[0211] For on-load voltage regulation, when the corresponding level of regulation delay time is reached and the operating constraints allow its operation, it is determined that the triggering is feasible.

[0212] The rules for determining the priority of actions include:

[0213] When reactive power regulation is feasible to be triggered, but on-load tap changer is not feasible to be triggered, only reactive power regulation is allowed.

[0214] When both reactive power regulation and on-load tap changer actions are feasible to trigger, reactive power regulation actions shall be given priority.

[0215] When reactive power regulation is not feasible to trigger, but on-load tap changer is feasible to trigger, on-load tap changer is permitted.

[0216] When neither of the two types of adjustment actions is feasible to trigger, the current operating state is maintained.

[0217] The reactive power regulation and on-load tap regulation control strategies are separated, and reactive power regulation and on-load tap regulation are respectively assigned to different time scales and regulation responsibilities. Reactive power regulation is used to undertake fast, small-amplitude, and continuous voltage regulation tasks, while on-load tap regulation is used to undertake low-frequency, large-range, and structural voltage regulation tasks. The two are independent of each other in terms of control logic, regulation frequency, and triggering conditions, but are constrained by unified rules.

[0218] Under this separation strategy, on-load tap regulation is no longer used as a direct response to instantaneous voltage fluctuations. Instead, it is defined by the day-ahead operation plan, which limits its feasible operating range and adjustment direction during the day's operation. Reactive power regulation, on the other hand, is implemented by the day-ahead real-time adjustment plan, which performs continuous or discrete voltage corrections based on the real-time operating status to suppress short-term fluctuations and reduce the triggering requirements of on-load tap regulation.

[0219] Based on the daily operation plan, the time scale and granularity of the plan are as follows: the plan is constructed using an hourly time scale, and the next day's operation cycle is divided into multiple consecutive planned time periods, with the duration of each planned time period preferably being 1 hour.

[0220] Time-based limitation of on-load tap changer operation domain: For each planned time period, the day-ahead operation plan generates a tap position operation domain for the on-load tap changer, which is used to limit the range of selectable tap positions of the on-load tap changer within that time period.

[0221] Preset reference direction for tap position: The adjustment direction is preset between adjacent planned time periods to define the structural direction of its cross-time period adjustment. The adjustment direction is used to indicate that when entering the next planned time period, the on-load tap changer should preferentially adjust in the direction of increasing or decreasing voltage, or maintain the current state, thereby reducing the uncertainty of adjustment decisions.

[0222] Step Six: Based on the aforementioned short-time output sequence, the local trend of change at the current moment is estimated using the linear least squares method to obtain the current short-term output change rate, the expression of which includes:

[0223] ;

[0224] in, This represents the current short-term rate of change in output. Within the sliding window Photovoltaic power output time series at any given moment It is a short-time output sequence. Let be the slope parameter of the linear trend to be estimated. The time index variable within the sliding window. The intercept parameter is the linear fitting model.

[0225] Step 7: Apply stage constraints to the trend slope based on the current short-term output change rate and the pre-acquired current time series stage label, and obtain the constraint slope. The expression includes:

[0226] ;

[0227] in, To constrain the slope, () is the amplitude limiting function. This is the label for the current time series stage. The minimum trend slope under the current time series label. This represents the maximum trend slope under the current time series label.

[0228] It should be noted that the current method for obtaining the time series stage label is exactly the same as the method mentioned above, only the initial photovoltaic power output time series is different.

[0229] Step 8: Obtain the predicted power output of photovoltaic power within the day based on the constraint slope. The expression includes:

[0230] ;

[0231] in, To predict the output, The sampling period is The preferred time is 15 minutes. This is a time series of photovoltaic power output.

[0232] Step Nine: Based on the predicted output of photovoltaic power during the day and the pre-constructed VQ droop control curve, optimize and control the reactive power regulation device:

[0233] The pre-constructed VQ droop control curve includes:

[0234] Voltage dead zone width Used to define the voltage range in which reactive power regulation does not operate;

[0235] droop slope It is used to characterize the proportional relationship between voltage deviation and reactive power output;

[0236] Maximum reactive power output ratio coefficient This is used to limit the effective utilization of reactive power output during the current operating phase;

[0237] Adjusting the output of the reactive power regulating device includes:

[0238] When the current timing stage label is low output stage, set the first voltage dead zone width. Set the first downward slope And limit the reactive power output ratio to the first ratio range. ;

[0239] When the current timing phase label is a disturbance phase, set the second voltage dead zone width. Set the second downward slope And limit the reactive power output ratio to the second ratio range. ;

[0240] When the current timing phase label is ramp-up phase, set the third voltage dead zone width. Set the third downward slope And limit the reactive power output ratio to the third ratio range. ;

[0241] When the current timing phase label is the fallback phase, the voltage dead zone width is gradually restored from the third voltage dead zone width to the second voltage dead zone width, and the droop slope is adjusted to the second droop slope.

[0242] When the current timing stage label is the plateau stage, set the second voltage dead zone width. Set a standard droop slope to maintain a normal reactive power output ratio;

[0243] in, , .

[0244] Step 10: Based on the results of reactive power output optimization and switching control, and the pre-defined feasible operating state space of the on-load tap changer during intraday operation, the regulation behavior of the reactive power regulation device during intraday operation is scheduled in a time-based manner. This is used to address voltage fluctuations caused by photovoltaic output within a shorter time scale, and to suppress the participation of the on-load tap changer in regulation while meeting operational constraints.

[0245] Based on the daily operation plan, the time scale and granularity of the plan are as follows: The daily operation plan is constructed using a minute-level time scale, dividing the daily operation cycle into multiple consecutive adjustment plan periods. The duration of each adjustment plan period is preferably 15 minutes, and it is updated in a rolling manner.

[0246] Time-based limitation of reactive power regulation operation domain: For each regulation plan period, the intraday real-time regulation plan generates the corresponding reactive power regulation strategy based on the current voltage status, intraday photovoltaic power forecast output, and the judgment results of multi-level delay strategy.

[0247] Preset of reactive power regulation reference level: Between adjacent regulation planning periods, the reference reactive power output level and regulation direction of the reactive power regulation device are preset to indicate that when entering the next regulation planning period, the reactive power regulation device should prioritize increasing reactive power output, decreasing reactive power output, or maintaining the current reactive power state unchanged.

[0248] Specifically, it also includes:

[0249] In the current iterative optimization control layer, feedback information of the running results is introduced to dynamically correct the optimization objective function and its weights, so that the generated running plan can gradually conform to the actual running state and avoid deviation of the adjustment effect due to model uncertainty, prediction bias or changes in the running environment.

[0250] The feedback information includes:

[0251] Voltage deviation at each key node during actual operation;

[0252] The actual number of times, timing of, and amplitude of action of the on-load tap changer;

[0253] The actual output and saturation state of the reactive power regulating device;

[0254] The deviation between the predicted and actual photovoltaic power output;

[0255] Evaluation results of the effectiveness of adjustment actions in the previous operating cycle.

[0256] The aforementioned daily operation plan, based on the above-mentioned multi-level delay strategy and action priority setting, pre-limits the feasible operating state space of the on-load tap changer during the daytime operation, so as to reduce the degree of freedom of the on-load tap changer during real-time control and avoid it from frequently participating in regulation under short-term fluctuation conditions.

[0257] Planning time scale and planning granularity: The plan is constructed using an hourly time scale, dividing the next day's operating cycle into multiple consecutive planning periods, with the duration of each planning period preferably being 1 hour.

[0258] Time-based limitation of on-load tap changer operation domain: For each planned time period, the day-ahead operation plan generates a tap position operation domain for the on-load tap changer, which is used to limit the range of selectable tap positions of the on-load tap changer within that time period.

[0259] Preset reference direction for tap position: The adjustment direction is preset between adjacent planned time periods to define the structural direction of its cross-time period adjustment. The adjustment direction is used to indicate that when entering the next planned time period, the on-load tap changer should preferentially adjust in the direction of increasing or decreasing voltage, or maintain the current state, thereby reducing the uncertainty of adjustment decisions.

[0260] Example 2:

[0261] Embodiment 2 of the present invention provides an on-load tap changer with multi-stage delay voltage regulation considering the timing characteristics of photovoltaic power output, comprising:

[0262] The sequence acquisition module is used to acquire the output data of photovoltaic power sources in the distribution area, and to form photovoltaic output time series and short-time output series based on the output data;

[0263] The sequence processing module is used to preprocess the photovoltaic power output time series, decompose it into multiple time scales, extract time series feature parameters and detect stage change points in sequence. It divides the photovoltaic power output time series into different candidate time series stages of transition from one operating state to another during the day's operation and outputs stage labels corresponding to the candidate time series stages.

[0264] A fluctuation level classification module is used to classify voltage into different fluctuation levels based on the extracted time-series feature parameters;

[0265] The adjustment delay time generation module is used to generate an adjustment delay time corresponding to the current operating state based on the voltage fluctuation level, the candidate time sequence stage, and the pre-built set of operating constraints.

[0266] The pre-defined module is used to determine the action priority based on the adjustment delay time and the pre-set action priority rules, and to make a decision on the action priority according to the feasibility criteria of different adjustment actions, so as to pre-define the feasible operating state space of the on-load tap changer during the daytime operation.

[0267] The local change trend estimation module is used to estimate the local change trend at the current moment based on the short-term output sequence using the linear least squares method, and obtain the current short-term output change rate.

[0268] The slope constraint module is used to apply stage constraints to the trend slope based on the current short-term output change rate and the pre-acquired current time series stage label, and obtain the constraint slope.

[0269] The predicted output acquisition module is used to obtain the predicted output of photovoltaic power within the day based on the constraint slope;

[0270] The reactive power output optimization and switching control module is used to optimize and control the reactive power regulation device based on the predicted output of photovoltaic power during the day and the pre-constructed VQ droop control curve.

[0271] The suppression and regulation module is used to schedule the regulation behavior of the reactive power regulation device during the daytime operation based on the results of reactive power output optimization and switching control and the pre-limitation of the feasible operating state space of the on-load tap changer during the daytime operation. It is used to deal with voltage fluctuations caused by photovoltaic output in a short time scale and suppress the participation of the on-load tap changer in regulation under the premise of meeting the operating constraints.

[0272] The on-load tap-changing multi-stage delayed voltage regulation device considering the timing characteristics of photovoltaic output provided in Embodiment 2 of the present invention can execute the on-load tap-changing multi-stage delayed voltage regulation method considering the timing characteristics of photovoltaic output provided in Embodiment 1 of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0273] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0274] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (devices), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and 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 process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0275] 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.

[0276] 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.

[0277] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-stage delayed voltage regulation method for on-load tap changer considering the timing characteristics of photovoltaic power output, characterized in that, include: Obtain the photovoltaic power output time series and short-time power output series of the photovoltaic power source in the distribution area; The photovoltaic power output time series is preprocessed, decomposed into multiple time scales, extracted into time series feature parameters, and detected stage change points in sequence to divide the photovoltaic power output time series into different candidate time series stages. Based on the extracted time-series feature parameters, the voltage is divided into different fluctuation levels; Based on the voltage fluctuation level, candidate time sequence stage, and pre-built set of operating constraints, an adjustment delay time corresponding to the current operating state is generated; Based on the adjustment delay time and the pre-set action priority adjudication rules, the action priority is adjudicated according to the feasibility criteria of different adjustment actions, thereby pre-limiting the feasible operating state space of the on-load tap changer during the daytime operation. Based on the aforementioned short-time output sequence, the local change trend at the current moment is estimated using the linear least squares method to obtain the current short-term output change rate; Apply stage constraints to the trend slope based on the current short-term output change rate and the pre-acquired current time series stage label, and obtain the constraint slope; Predicted power output of photovoltaic systems within a day is obtained based on the constrained slope. Based on the predicted output of photovoltaic power during the day and the pre-constructed VQ droop control curve, the reactive power regulation device is optimized and its switching is controlled. Based on the results of reactive power output optimization and switching control, and the pre-definition of the feasible operating state space of the on-load tap changer during the daytime operation, the adjustment behavior of the reactive power regulation device during the daytime operation is arranged in a time-based manner to suppress the participation of the on-load tap changer in regulation.

2. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 1, characterized in that, The photovoltaic power output time series is preprocessed, decomposed into multiple time scales, and its time series feature parameters are extracted and stage change points are detected sequentially. This process divides the photovoltaic power output time series into different candidate time series stages, including: The photovoltaic power output time series is normalized to obtain a normalized photovoltaic power output time series. Anomaly removal is performed on the normalized photovoltaic power output time series to obtain the anomaly-removed photovoltaic power output time series; The photovoltaic power output time series after anomaly removal is smoothed to obtain the smoothed photovoltaic power output time series. The smoothed photovoltaic power output time series is decomposed into multiple time scales to obtain the trend component reflecting the intraday change trend and the fluctuation component reflecting the short-term fluctuation characteristics. Based on the trend component and fluctuation component, time series feature parameters are extracted, including trend slope, short-term ramp rate, fluctuation intensity and fluctuation frequency. The quantity to be monitored is constructed based on the time series feature parameters, wherein the quantity to be monitored is at least one of the time series feature parameters; Based on the monitored quantity, a forward cumulative sum and a reverse cumulative sum are constructed, and the expressions include: ； ； ； in, For positive cumulative sum, For reverse cumulative sum, For the quantity to be monitored, The baseline mean This is the drift parameter, used to suppress small random disturbances in the offset. The standard deviation of the monitored quantity during the stable phase. Standard coefficients; like ,determination To identify candidate moments for stage change, the photovoltaic power output time series is divided into different candidate moment time series stages.

3. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 2, characterized in that, Based on the extracted time-series feature parameters, the voltage is divided into different fluctuation levels, including: Based on the extracted time-series feature parameters, a comprehensive fluctuation intensity index is calculated, the expression of which includes: ； in, As the first weight, As the second weight, As the third weight, As a comprehensive index of volatility intensity, This is the number of sampling points within the preset statistical time window; Volatility levels are classified according to a comprehensive volatility intensity index: when The fluctuation level is small fluctuation; when The fluctuation level is medium fluctuation; when The fluctuation level is large fluctuation; in, This is the lower limit of the short-time rate of change parameter. This represents the upper limit of the short-time rate of change parameter.

4. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 3, characterized in that, Based on the voltage fluctuation level, candidate time series stage, and pre-built set of operating constraints, an adjustment delay time corresponding to the current operating state is generated, and the expression includes: ； in, The timing sequence representing the candidate moments for photovoltaic power output. Indicates the voltage fluctuation level. Indicates the set of constraints to be executed. This indicates the adjustment delay time corresponding to the current operating state; The specific steps include: Set the base delay time according to the voltage fluctuation level; The base delay time is corrected based on the candidate timing phase of photovoltaic power output to obtain the corrected delay time; The modified delay time is trimmed or adjusted according to the set of operating constraints to obtain the adjusted delay time; It also includes a hierarchical setting principle for multi-level delays. The hierarchical setting principle for multi-level delays includes at least two or more different delay parameter groups, and different delay levels meet the following setting principles: Setting 1: When the photovoltaic output is in the disturbance segment of the aforementioned timing stage identification results, and the voltage fluctuation level is within the small fluctuation level range, a first-level delay time is generated. The first level of delay time is used to suppress adjustment actions caused by small fluctuations within a short time scale; Setting 2: When the photovoltaic output is in the ramp-up or pullback phase of the aforementioned timing stage identification results, and the voltage fluctuation level is in the large fluctuation range, a second-level delay time is generated. The second-level delay time is used to intervene and adjust in a timely manner when the voltage continues to deviate from a clear trend; Setting 3: When the set of operating constraints indicates that the current reactive power adjustment margin is sufficient, the generated delay time is corrected in the direction of extension to obtain the corrected delay time: ； in, To correct the delay time, The positive delay correction amount is used to further suppress unnecessary adjustment actions; Setting 4: When the set of operating constraints indicates that the current reactive power regulation capacity is close to the capacity limit, the rate of change is limited, or the number of regulation times is close to the preset limit, the generated delay time is corrected in the direction of shortening to obtain the corrected delay time: ； in, This is the reverse delay correction amount, and it is a positive number.

5. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 1, characterized in that, Based on the adjustment delay time and pre-set action priority adjudication rules, and according to the feasibility criteria of different adjustment actions, the action priority is adjudicated to achieve the pre-definition of the feasible operating state space of the on-load tap changer during daytime operation, including: For different types of reactive power regulation and on-load tap changer actions, feasibility criteria are constructed for each under the current operating state. Its feasibility function is defined as: ； When the function meets the preset conditions, it is determined that the adjustment action is feasible to be triggered in the current operating state: For reactive power regulation actions, if the user can participate in the regulation within the operating constraints, it is determined that the action is feasible. For on-load voltage regulation, when the corresponding level of regulation delay time is reached and the operating constraints allow its operation, it is determined that the triggering is feasible. The rules for determining the priority of actions include: When reactive power regulation is feasible to be triggered, but on-load tap changer is not feasible to be triggered, only reactive power regulation is allowed. When both reactive power regulation and on-load tap changer actions are feasible to trigger, reactive power regulation actions shall be given priority. When reactive power regulation is not feasible to trigger, but on-load tap changer is feasible to trigger, on-load tap changer is permitted. When neither of the two types of adjustment actions is feasible to trigger, the current operating state is maintained.

6. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 1, characterized in that, Also includes: In the current iterative optimization control layer, feedback information of the running results is introduced to dynamically correct the optimization objective function and its weights, so that the generated running plan can gradually conform to the actual running state and avoid deviation of the adjustment effect due to model uncertainty, prediction bias or changes in the running environment. The feedback information includes: Voltage deviation at each key node during actual operation; The actual number of times, timing of, and amplitude of operation of the on-load tap changer; The actual output and saturation state of the reactive power regulating device; The deviation between the predicted and actual photovoltaic power output; Evaluation results of the effectiveness of adjustment actions in the previous operating cycle.

7. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 1, characterized in that, Based on the aforementioned short-time output sequence, the local trend of change at the current moment is estimated using the linear least squares method to obtain the current short-term output change rate, the expression of which includes: ； in, This represents the current short-term rate of change in output. Within the sliding window Photovoltaic power output time series at any given moment It is a short-time output sequence. Let be the slope parameter of the linear trend to be estimated. The time index variable within the sliding window. The intercept parameter is the linear fitting model.

8. The on-load tap-changing multi-stage delayed voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 7, characterized in that, Based on the current short-term output change rate and the pre-acquired current time-series stage label, a stage constraint is applied to the trend slope to obtain the constraint slope, the expression of which includes: ； in, To constrain the slope, () is the amplitude limiting function. This is the label for the current time series stage. The minimum trend slope under the current time series label. The maximum trend slope under the current time series stage label; The predicted power output of photovoltaic systems during the day is obtained based on the constrained slope. The expression includes: ； in, To predict the output, The sampling period is The preferred time is 15 minutes. This is a time series of photovoltaic power output.

9. The on-load tap-changing multi-stage time-delay voltage regulation method considering the timing characteristics of photovoltaic power output according to claim 1, characterized in that, The pre-constructed VQ sag control curve includes: Voltage dead zone width Used to define the voltage range in which reactive power regulation does not operate; droop slope It is used to characterize the proportional relationship between voltage deviation and reactive power output; Maximum reactive power output ratio coefficient This is used to limit the effective utilization of reactive power output during the current operating phase; Adjusting the output of the reactive power regulating device includes: When the current timing stage label is low output stage, set the first voltage dead zone width. Set the first downward slope And limit the reactive power output ratio to the first ratio range. ; When the current timing phase label is a disturbance phase, set the second voltage dead zone width. Set the second downward slope And limit the reactive power output ratio to the second ratio range. ; When the current timing phase label is ramp-up phase, set the third voltage dead zone width. Set the third downward slope And limit the reactive power output ratio to the third ratio range. ; When the current timing phase label is the fallback phase, the voltage dead zone width is gradually restored from the third voltage dead zone width to the second voltage dead zone width, and the droop slope is adjusted to the second droop slope. When the current timing stage label is the plateau stage, set the second voltage dead zone width. Set a standard droop slope to maintain a normal reactive power output ratio; in, , .

10. A multi-stage delayed voltage regulation device for on-load tap changer that considers the timing characteristics of photovoltaic power output, characterized in that, include: The sequence acquisition module is used to acquire the photovoltaic power output time series and short-time power output series of photovoltaic power sources in the distribution area; The sequence processing module is used to perform preprocessing, multi-timescale decomposition, time series feature parameter extraction and stage change point detection on the photovoltaic power output time series in sequence, and divide the photovoltaic power output time series into different candidate time series stages. A fluctuation level classification module is used to classify voltage into different fluctuation levels based on the extracted time-series feature parameters; The adjustment delay time generation module is used to generate an adjustment delay time corresponding to the current operating state based on the voltage fluctuation level, the candidate time sequence stage, and the pre-built set of operating constraints. The pre-defined module is used to determine the action priority based on the adjustment delay time and the pre-set action priority rules, and to make a decision on the action priority according to the feasibility criteria of different adjustment actions, so as to pre-define the feasible operating state space of the on-load tap changer during the daytime operation. The local change trend estimation module is used to estimate the local change trend at the current moment based on the short-term output sequence using the linear least squares method, and obtain the current short-term output change rate. The slope constraint module is used to apply stage constraints to the trend slope based on the current short-term output change rate and the pre-acquired current time series stage label, and obtain the constraint slope. The predicted output acquisition module is used to obtain the predicted output of photovoltaic power within the day based on the constraint slope; The reactive power output optimization and switching control module is used to optimize and control the reactive power regulation device based on the predicted output of photovoltaic power during the day and the pre-constructed VQ droop control curve. The suppression and regulation module is used to schedule the regulation behavior of the reactive power regulation device during the daytime operation based on the results of reactive power output optimization and switching control and the pre-limitation of the feasible operating state space of the on-load tap changer during the daytime operation, so as to suppress the participation of the on-load tap changer in regulation.

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