Power distribution area voltage treatment method in uninterruptible power supply scene

Abstract

The invention relates to the technical field of power distribution area voltage regulation and control, in particular to a power distribution area voltage treatment method in an uninterruptible power supply scene. According to the method, disturbance intensity is obtained according to a prediction residual error of voltage data at each time point and is used for representing load unpredictability of a current power distribution area working condition; a voltage offset risk indicator is further obtained based on the distribution of the voltage in the dead zone range. The adjustment cost of the two modes is determined based on the disturbance intensity and the voltage deviation risk index, the adjustment cost of the OLTC is further adjusted based on the working condition change rate, and then an effective adjustment mode instruction is selected. According to the method, dynamic and optimal distribution of functions of the voltage regulating equipment is realized, voltage oscillation possibly caused by equipment action conflicts originally is converted into a stable and ordered control right handover process, voltage treatment is completed on the premise that secondary disturbance is not introduced, and the voltage regulation efficiency is improved. And the core requirements of the uninterrupted power supply scene on the continuity and the stability of the power supply process are directly met.

Description

Technical Field

[0001] This invention relates to the field of distribution transformer area voltage regulation technology, and specifically to a method for managing distribution transformer area voltage in uninterrupted power supply scenarios. Background Technology

[0002] As the direct end of power supply to users, the power quality, especially voltage stability, of distribution substations is crucial to social production and daily life. With the large-scale integration of new loads and power sources such as electric vehicle charging stations and distributed photovoltaic systems, the voltage in these substations generally exhibits rapid time-varying and highly random fluctuations, posing a severe challenge to traditional voltage management methods. To address this issue, distribution substations are typically equipped with both on-load tap-changing transformers (OLTCs) and static var generators (SVGs). OLTCs, by mechanically adjusting the transformer turns ratio, are suitable for correcting continuous and large-amplitude systemic voltage deviations caused by changes in base load, but their response speed is slow and they suffer from mechanical lifespan loss. SVGs, on the other hand, use power electronics technology for rapid dynamic reactive power compensation, excelling at smoothing transient, high-frequency voltage fluctuations, but their compensation capacity is limited.

[0003] In existing technologies, these two types of devices typically operate based on their own independent control logic, which is based on static thresholds. The fundamental flaw of this control method is its inability to distinguish between two distinct types of voltage exceedances: one is a systemic deviation caused by a slow, continuous increase in base load, and the other is transient, high-frequency fluctuations generated during periods of drastic switching in transformer operating conditions (such as the concentrated start-up and shutdown of numerous fast-charging stations during the midday rush hour in commercial areas). Existing methods treat these two situations in a homogenized manner, which easily leads to timing conflicts between the slow adjustment action of the OLTC and the rapid compensation action of the SVG, causing voltage over-adjustment, secondary fluctuations, and even control oscillations. This not only deteriorates voltage quality but also causes ineffective mechanical wear of the OLTC and waste of the SVG's compensation capacity. Summary of the Invention

[0004] To address the technical problem that existing technologies use a homogenized approach to voltage regulation for both OLTC and SVG modes, making it impossible to select the correct and effective regulation mode to cope with real-time distribution transformer voltage conditions, the present invention aims to provide a distribution transformer voltage management method for uninterrupted power supply scenarios. The specific technical solution adopted is as follows: This invention proposes a method for managing the voltage of distribution substations in uninterruptible power supply scenarios, the method comprising: The active power sequence of the power system under each preset sampling period is obtained, and the prediction residual of each time point in the active power sequence is obtained using a sequence prediction algorithm. The disturbance intensity is obtained based on the volatility of the prediction residual. The voltage deviation risk index is obtained based on the distribution of voltage over a preset dead zone range under the sampling period. The rate of change of operating conditions in each sampling period is obtained based on the difference in disturbance intensity and the difference in voltage offset risk index between adjacent sampling periods. In each sampling period, the first regulation cost of OLTC and the second regulation cost of SVG are evaluated based on the magnitude of the disturbance intensity and the magnitude of the voltage offset risk index, respectively; the first regulation cost is corrected using the operating condition change rate to obtain the third regulation cost; The voltage regulation mode command is determined by comparing the third regulation cost with the second regulation cost.

[0005] Furthermore, the method for obtaining the prediction residual includes: For the actual active power data at each time point, the predicted active power data is obtained based on the historical active power data sequence under the preset historical time period, and the difference between the actual active power data and the predicted active power data is used as the prediction residual.

[0006] Furthermore, the method for obtaining the disturbance intensity includes: The standard deviation of the predicted residual is used as the disturbance intensity.

[0007] Furthermore, the method for obtaining the voltage offset risk index includes: The last voltage data in the sampling period is taken as the real-time voltage; the voltage offset risk index of the initial sampling period is set to 0. If the real-time voltage is within the dead zone, the voltage offset risk index of the previous sampling period is attenuated according to a preset attenuation coefficient to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage; the lower limit of attenuation is set to 0. If the real-time voltage is outside the dead zone, the nearest difference distance between the real-time voltage and the dead zone is obtained; the voltage offset risk index of the previous sampling period is increased based on the nearest difference distance to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage.

[0008] Furthermore, the method for obtaining the rate of change of operating conditions includes: After normalizing the disturbance intensity and voltage offset risk indicators, the normalization results are used as the feature vectors of each sampling period; the Euclidean distance between the feature vectors of adjacent sampling periods is used as the rate of change of the operating condition.

[0009] Furthermore, methods for normalizing the disturbance intensity and voltage offset risk indicators separately include: For data to be normalized, the data at 95% of the corresponding dimension's data interval is used as the baseline value. Each data point to be normalized is used as the numerator, and the baseline value is used as the denominator. If the ratio is greater than 1, the normalization result is set to 1; if the ratio is not greater than 1, the ratio is used as the normalization result.

[0010] Furthermore, the method for obtaining the first adjustment cost includes: The disturbance intensity is weighted using a preset first weight to obtain a first weighted disturbance intensity; the voltage offset risk index is weighted using a preset second weight to obtain a first weighted voltage offset risk index; the sum of the first weight and the second weight is a positive integer 1; The adjustment amount is obtained by adjusting the fixed marginal wear cost of the OLTC based on the difference between the first weighted disturbance intensity and the first weighted voltage offset risk index, thus obtaining the first adjustment cost.

[0011] Furthermore, the method for obtaining the second adjustment cost includes: The disturbance intensity is weighted using a preset third weight to obtain a second weighted disturbance intensity; the voltage offset risk index is weighted using a preset fourth weight to obtain a second weighted voltage offset risk index; the sum of the third weight and the fourth weight is a positive integer 1; The adjustment amount is obtained by summing the second weighted disturbance intensity and the second weighted voltage offset risk index, and the opportunity cost of SVG in the current sampling period is adjusted to obtain the second adjustment cost.

[0012] Furthermore, the method for obtaining the third adjustment cost includes: After normalizing the rate of change of operating conditions, add it to a positive integer 1 to obtain a correction coefficient; multiply the correction coefficient by the first adjustment cost as the third adjustment cost.

[0013] Furthermore, the instruction to determine the voltage regulation mode of the distribution area includes: If the third adjustment cost is less than or equal to the second adjustment cost, the OLTC-dominated collaborative voltage regulation mode command is selected; if the third adjustment cost is greater than the second adjustment cost, the SVG independent compensation mode is selected.

[0014] The present invention has the following beneficial effects: This invention shifts the basis of control decision-making from judging the instantaneous state of the distribution transformer area's operating conditions to a quantitative assessment of the dynamic stability of the operating conditions. To achieve this objective, this invention first obtains the disturbance intensity based on the prediction residuals of voltage data at various time points, which is used to characterize the load unpredictability of the current distribution transformer area's operating conditions. Furthermore, it obtains a voltage deviation risk index based on the voltage distribution within the dead zone. For the OLTC voltage adjustment mode, this mode is suitable for operating conditions where the voltage continuously exceeds limits and there are non-random disturbances; for the SVG voltage adjustment mode, this mode is suitable for operating conditions where the voltage continuously exceeds limits and generates high-frequency transient random disturbances. Therefore, the adjustment costs of the two modes can be determined based on the disturbance intensity and the voltage deviation risk index. Furthermore, considering the inherent mechanical action delay of the OLTC's "grandchild" seconds, if the operating conditions of the distribution transformer area change drastically during this delay, the original decision may not only fail but may even exacerbate voltage fluctuations due to lagging adjustment. Therefore, this invention further considers the delay issue and obtains the rate of change of operating conditions between adjacent sampling periods. This characteristic directly reflects the overall operating condition stability of the distribution transformer area, and therefore, the adjustment cost of the OLTC can be further adjusted based on this characteristic. Ultimately, an effective regulation mode command can be selected based on the regulation costs of the two modes. This invention achieves dynamic and optimal allocation of voltage regulation equipment functions, transforming voltage oscillations that might otherwise be caused by equipment action conflicts into a smooth and orderly control handover process. This allows for voltage regulation without introducing secondary disturbances, directly meeting the core requirements of continuity and stability in uninterrupted power supply scenarios. Attached Figure Description

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating a distribution substation voltage management method for an uninterrupted power supply scenario, as provided in one embodiment of the present invention. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a distribution substation voltage management method for uninterrupted power supply scenarios proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, 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.

[0019] The following description, in conjunction with the accompanying drawings, details a specific scheme for a distribution substation voltage management method in an uninterrupted power supply scenario provided by the present invention.

[0020] Please see Figure 1 The diagram illustrates a flowchart of a distribution substation voltage management method for an uninterrupted power supply scenario according to an embodiment of the present invention. The method includes: Step S1: Obtain the active power sequence in the power system under each preset sampling period, use the sequence prediction algorithm to obtain the prediction residual at each time point in the active power sequence, obtain the disturbance intensity based on the volatility of the prediction residual, and obtain the voltage offset risk index based on the voltage distribution over the preset dead zone range under the sampling period.

[0021] This invention describes the process of optimizing and adjusting the operating conditions of a distribution transformer area under different driving factors. These driving factors include, for example, high-frequency, transient disturbances caused by the disorderly charging of numerous electric vehicles, and persistent, systematic shifts caused by the slow growth of the regional base load. These two different operating conditions require targeted adjustment modes. Therefore, in order to confirm and quantify the operating condition type in the current sampling period, step S1 analyzes and extracts features from the continuous time-series data collected by the data monitoring system. The high-dimensional continuous raw time-series data is refined into low-dimensional, structured features that can directly characterize the inherent characteristics of the current transformer area's operating conditions. These extracted features are then used to quantitatively profile the transformer area's operating conditions in the current sampling period.

[0022] The fluctuation of total active power in a distribution area is caused by a superposition of predictable periodic trends and unpredictable random disturbances. OLTC (Optical Voltage Transmission Control) adjusts the transformer ratio to correct the systemic voltage shift caused by the former; while SVG (Static Var Generator) provides rapid reactive power compensation, specifically designed to suppress high-frequency transient fluctuations caused by the latter. Therefore, accurately separating and quantifying the unpredictable disturbance components from the total power fluctuation is a technical prerequisite for achieving proper equipment function matching. This invention first obtains the active power sequence in the power system under various preset sampling periods. For each time point in the active power sequence under each sampling period, a sequence prediction algorithm can be used to obtain the predicted value at that time point based on its historical data. Because the predicted value is a value predicted based on historical patterns, the volatility of the prediction residual between the predicted value and the actual value can effectively characterize the random instability of the operating conditions under the current sampling period.

[0023] Preferably, in this embodiment of the invention, the method for obtaining the predicted residual includes: For the actual active power data at each time point, the predicted active power data is obtained based on the historical active power data sequence under the preset historical time period, and the difference between the actual active power data and the predicted active power data is used as the prediction residual.

[0024] In this embodiment of the invention, the sampling period is set to 1 hour, and the sampling frequency is set to 1 minute, meaning that a data sequence of length 60 is obtained every hour. The sequence prediction algorithm used in this embodiment is an autoregressive model, which searches backward 60 data points for each time point as its historical data, i.e., the historical time period is set to 1 hour. Prediction is performed based on the historical data, thereby capturing regular and predictable predicted values ​​in the sequence.

[0025] Preferably, in this embodiment of the invention, the standard deviation of the predicted residual is used as the disturbance intensity. A larger standard deviation indicates a more unstable distribution of the predicted residual, directly reflecting the randomness and severity of load impacts on the distribution substation under the current sampling period.

[0026] Due to the inherent delayed action logic within OLTC devices, they only respond to persistent voltage exceedance issues, ignoring brief fluctuations. If the cooperative control system cannot perceive and quantify this persistence, it will struggle to predict the OLTC's own action intentions, leading to control conflicts. Therefore, this embodiment of the invention obtains a voltage offset risk index based on the voltage distribution within a preset dead zone range during the sampling period. This voltage offset risk index serves as an evaluation metric that externalizes and continuously reflects the OLTC's internal delayed logic, making its tolerance for voltage offsets and action tendencies transparent and knowable.

[0027] It should be noted that the voltage dead zone range of the distribution radio area can be preset in the OLTC controller based on the actual situation, without further details or limitations.

[0028] Preferably, in this embodiment of the invention, the method for obtaining the voltage offset risk index includes: Since the embodiments of the present invention perform real-time analysis on the basis of each sampling period, and there are multiple voltage data within a sampling period, the last voltage data within the sampling period is taken as the real-time voltage.

[0029] It should be noted that in other embodiments of the present invention, the average voltage within the sampling period can also be used as the real-time voltage, which will not be elaborated or limited in detail.

[0030] Considering that the purpose of this embodiment is to quantify the voltage offset risk index, enabling it to serve as an evaluation metric that externalizes and continuously represents the internal delay logic of the OLTC, this embodiment employs an iterative update method. By setting a specific voltage offset risk index in the initial sampling period, and updating the voltage offset risk index in the previous sampling period in the new sampling period based on the relationship between the real-time voltage and the dead zone range, this achieves the objective of this embodiment. In this embodiment, the voltage offset risk index for the initial sampling period is set to 0.

[0031] If the real-time voltage is within the dead zone, the voltage offset risk index of the previous sampling period is attenuated according to a preset attenuation coefficient to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage. In this embodiment of the invention, the attenuation coefficient is set to 0.9, and attenuation is achieved by multiplying the attenuation coefficient by the voltage offset risk index of the previous sampling period. This attenuation process simulates the phenomenon that the urgency of the OLTC's action gradually decreases over time after the voltage returns to normal. At the same time, in order to avoid unlimited numerical attenuation affecting the actual physical meaning, the lower limit of attenuation is set to 0. That is, if the voltage offset risk index of the previous sampling period is already 0, and attenuation is required in the current sampling period, the voltage offset risk index of the current sampling period is directly set to 0.

[0032] If the real-time voltage is outside the dead zone, the nearest difference distance between the real-time voltage and the dead zone is obtained; the voltage offset risk index of the previous sampling period is increased based on the nearest difference distance to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage.

[0033] In this embodiment of the invention, the nearest difference distance is quantified by the square of the absolute value of the difference between the real-time voltage and the boundary of the nearest dead zone. After normalizing the nearest difference distance using range standardization, it is added to the voltage offset risk index of the previous sampling period as an increase adjustment amount to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage.

[0034] Step S2: Obtain the operating condition change rate for each sampling period based on the difference in disturbance intensity and voltage offset risk index between adjacent sampling periods.

[0035] Because OLTCs have an inherent mechanical action delay of several seconds to tens of seconds, the effect of a voltage regulation decision made based on the system state at time t will only be reflected at time t+Δt. If the operating conditions of the transformer area change drastically during the delay period, the original decision may not only fail but may even exacerbate voltage fluctuations due to the delayed regulation. Therefore, in order to assess the future risk of issuing an OLTC voltage regulation command at time t, it is necessary to quantify the probability of a significant change in system operating conditions from t to t+Δt. In this embodiment of the invention, to assess the characteristics of operating condition changes during the delay period, for each sampling period, the difference in disturbance intensity and the difference in voltage offset risk index between the previous adjacent sampling period are calculated. The larger the difference in these two factors, the greater the rate of change in operating conditions under the current sampling period.

[0036] Preferably, in this embodiment of the invention, considering that the two features obtained in step S1 can characterize the operating conditions under the current sampling period, but the two features differ in dimensions and cannot be directly used to calculate the rate of change of operating conditions, in this embodiment of the invention, after normalizing the disturbance intensity and voltage offset risk index respectively, the normalization result is used as the feature vector of each sampling period; the Euclidean distance between the feature vectors of adjacent sampling periods is used as the rate of change of operating conditions. The rate of change of operating conditions is a unitless scalar, and its magnitude directly reflects the stability of the overall operating conditions of the transformer area. The closer the value is to 0, the more stable the operating conditions of the transformer area are, and neither the load characteristics nor the voltage offset has changed significantly. At this time, the regulation effect of OLTC is predictable. A significantly increased value clearly indicates that the transformer area is undergoing a drastic operating condition switching process, the system stability is poor, and any slow regulation decision based on historical information at this time is accompanied by extremely high uncertainty risk.

[0037] Furthermore, to enhance the robustness of the benchmark to extreme and sporadic outliers during the normalization process, methods for normalizing the disturbance intensity and voltage offset risk indices separately include: For data to be normalized, the data at 95% of the corresponding dimension's data interval is used as the baseline value. Each data point to be normalized is used as the numerator, and the baseline value is used as the denominator. If the ratio is greater than 1, the normalization result is set to 1; if the ratio is not greater than 1, the ratio is used as the normalization result.

[0038] It should be noted that when calculating the Euclidean distance, the normalized disturbance intensity can be used as the horizontal axis and the normalized voltage offset risk index as the vertical axis, thus constructing a two-dimensional coordinate system. The feature vector of each sampling period can have a mapping point in the two-dimensional coordinate system, thereby effectively calculating the Euclidean distance and obtaining the rate of change of operating conditions.

[0039] Step S3: In each sampling period, evaluate the first regulation cost of OLTC and the second regulation cost of SVG according to the magnitude of disturbance intensity and voltage offset risk index; correct the first regulation cost using the rate of change of operating conditions to obtain the third regulation cost.

[0040] For voltage regulation decisions in distribution substations, it is necessary to determine the appropriate regulation mode based on the operating conditions. Therefore, in each sampling period, this embodiment of the invention evaluates the first regulation cost of the OLTC and the second regulation cost of the SVG based on the magnitude of the disturbance intensity and the voltage deviation risk index. The regulation cost quantifies the functional suitability and resource consumption of the regulation system under the corresponding mode, thus, an effective regulation measurement can be selected based on the comparison of regulation costs.

[0041] The embodiments of the present invention further consider that the rate of change of operating conditions will affect the execution of the OLTC control strategy. The larger the rate of change of operating conditions, the less suitable it is for OLTC control. Therefore, the first adjustment cost can be further corrected by the rate of change of operating conditions to obtain the third adjustment cost.

[0042] Preferably, the method for obtaining the first adjustment cost in this invention includes: The disturbance intensity is weighted using a preset first weight to obtain a first weighted disturbance intensity; the voltage offset risk index is weighted using a preset second weight to obtain a first weighted voltage offset risk index; the sum of the first weight and the second weight is a positive integer 1. In this embodiment of the invention, the first weight and the second weight are used to balance the influence of the two dimensions. In this embodiment of the invention, the disturbance intensity dimension is preferred as the benchmark, so the first weight is set to be greater than the second weight. The first weight is set to 0.6 and the second weight is set to 0.4. In other embodiments of the invention, the specific settings can be adjusted according to the actual situation, which will not be elaborated here.

[0043] The adjustment amount is obtained by adjusting the fixed marginal wear cost of the OLTC based on the difference between the first weighted disturbance intensity and the first weighted voltage offset risk index, thus obtaining the first adjustment cost. It should be noted that, in this embodiment of the invention, the adjustment amount is the difference between the first weighted disturbance intensity and the first weighted voltage offset risk index.

[0044] Preferably, in this embodiment of the invention, the method for obtaining the second adjustment cost includes: The disturbance intensity is weighted using a preset third weight to obtain a second weighted disturbance intensity; the voltage offset risk index is weighted using a preset fourth weight to obtain a second weighted voltage offset risk index; the sum of the third and fourth weights is a positive integer 1. It should be noted that the third weight should be equal to the first weight set above, and similarly, the fourth weight should be equal to the second weight set above; further details will not be elaborated upon.

[0045] The adjustment amount is obtained by summing the second weighted disturbance intensity and the second weighted voltage offset risk index, and the opportunity cost of SVG in the current sampling period is adjusted to obtain the second adjustment cost.

[0046] It should be noted that the fixed marginal wear cost of OLTC and the opportunity cost of SVG in the current sampling period mentioned above are technical characteristics known to those skilled in the art. Their definitions and quantification methods are also well-known to those skilled in the art. The specific characteristics are briefly described as follows: (1) The fixed marginal wear cost of an OLTC represents the monetizable average equipment loss caused by each gear switching operation. This cost mainly stems from irreversible mechanical wear and arc erosion during the switching process. Its meaning is to transform the abstract equipment lifespan into a concrete economic value, thereby realizing an economic trade-off between equipment lifespan and voltage quality in control decisions. Its quantification method is well-known in engineering, and the full life cycle cost allocation method is usually adopted, that is, the average cost of a single operation is calculated based on the equipment's overhaul cost, contact replacement cost, and its mechanical and electrical lifespan (rated number of operations).

[0047] (2) The opportunity cost of the current reactive power output or remaining capacity of SVG measures the highest potential benefit forgone when its current capacity is used to perform a predetermined reactive power support task, which could have been obtained by using it for other potentially more valuable purposes (such as dealing with future voltage crises or participating in market transactions). The core meaning of this cost is that it reflects the scarcity and dynamic value of SVG flexibility. It warns the control system that consuming current capacity has a "cost" and that resources must be reserved for potentially more important future needs. Its quantification method is well known in power economics. It can usually be obtained by solving the optimal power flow (OPF) model to obtain the shadow price related to reactive power capacity constraints, or by directly referring to the real-time reactive power auxiliary service clearing price in the power market for dynamic evaluation.

[0048] Preferably, in this embodiment of the invention, the method for obtaining the third adjustment cost includes: After normalizing the rate of change of operating conditions, it is added to a positive integer 1 to obtain a correction coefficient; the product of the correction coefficient and the first adjustment cost is taken as the third adjustment cost. It should be noted that the normalization method for the rate of change of operating conditions can be the range standardization method, the specific content of which is a well-known technique to those skilled in the art and will not be elaborated here.

[0049] Step S4: Compare the third regulation cost and the second regulation cost to determine the voltage regulation mode command.

[0050] In this embodiment of the invention, a higher adjustment cost indicates lower functional adaptability of the voltage regulation system in the distribution substation when executing the corresponding mode, and greater resource consumption. Therefore, the voltage regulation mode command can be determined by comparing the third adjustment cost and the second adjustment cost.

[0051] Preferably, in this embodiment of the invention, if the third adjustment cost is less than or equal to the second adjustment cost, the OLTC-dominated collaborative voltage regulation mode command is selected; if the third adjustment cost is greater than the second adjustment cost, the SVG independent compensation mode is selected.

[0052] This invention addresses voltage management in distribution substations under uninterrupted power supply (UPS) scenarios. To ensure the uninterrupted nature of UPS, the voltage management process itself must not introduce secondary disturbances (such as voltage over-adjustment or oscillation), thereby affecting users' continuous power supply. The fundamental flaw of existing technologies lies in the isolated and delayed switching of control commands. This makes them highly susceptible to secondary voltage surges at the moment of control handover between the OLTC and SVG due to the drastic superposition of adjustment effects, directly violating the core requirement of "uninterrupted power supply." This invention, however, transforms the originally high-risk control mode switching process into a deterministic, conflict-free, and smooth transition.

[0053] When the system selects the SVG independent compensation mode command, it indicates that the current voltage fluctuations exhibit high-frequency, transient characteristics, or that the system is undergoing a drastic change in operating conditions. Neither of these situations is suitable for regulation by the slow-responding and irreversible OLTC. Therefore, the system issues an OLTC voltage regulation function lockout command to the OLTC's intelligent controller. This command temporarily disables the OLTC's automatic voltage regulation function, preventing any unexpected voltage adjustment actions, thus allowing the SVG to independently handle the voltage stabilization task. This proactive isolation of the slow-speed regulating device ensures the agility and reliability of voltage regulation during high-frequency grid disturbances.

[0054] When the system selects the OLTC-led coordinated voltage regulation mode command, it indicates that the current voltage deviation is persistent and trending, and the system's operating conditions are stable and suitable for the OLTC to fundamentally correct the voltage platform. The system first sends an OLTC voltage regulation function enable command to the OLTC controller, releasing its lockout state and allowing it to prepare for action based on its own voltage and delay logic. However, to eliminate the potential conflict between the actual OLTC voltage adjustment and the SVG compensation action, the system will simultaneously execute the forward-looking coordinated strategy described in S3.2.

[0055] This invention further considers that, for OLTC-dominated coordinated voltage regulation mode commands, a single voltage adjustment action by the OLTC will cause a step change in voltage (e.g., a momentary increase of 1.5%). If, at the moment of its action, the SVG is still performing high-intensity reactive power compensation, the combined effect of the two will inevitably lead to severe voltage over-adjustment, thereby triggering a violent reverse action of the SVG and generating oscillations. To eliminate this potential hazard in uninterrupted power supply scenarios, this invention further provides an active and smooth control handover strategy, specifically including: (1) After determining the OLTC-dominated coordinated voltage regulation mode instruction, an SVG control dead zone temporary relaxation instruction is immediately generated and sent to the SVG controller. The core content of this instruction is to temporarily adjust its voltage control dead zone from the original, high-requirement setpoint (e.g., [0.98, 1.02] pu) to a relatively relaxed range (e.g., [0.96, 1.04] pu). The direct consequence of this operation is that the SVG will become "insensitive" to voltage deviations within a certain range, thereby actively and gradually reducing its reactive power output. This process is not abruptly shutting down the SVG, but a gradual "control concession". This concession behavior reserves sufficient voltage regulation space in advance for the upcoming voltage step correction provided by the OLTC.

[0056] (2) When the system detects through SCADA that the OLTC has completed a gear adjustment action (for example, reading that its tap position Tap_pos has changed), or when the decision result at the next analysis cycle t+1 is SVG independent compensation mode, the system will issue an instruction again to restore the control dead zone of the SVG to its original setting value, so that it can take over the fine voltage smoothing task again.

[0057] This forward-looking collaborative strategy transforms the potentially severe control conflicts and voltage oscillations into a smooth and orderly handover of control. It ensures that at the moment of OLTC activation, the voltage will not experience over-adjustment surges due to compensation superposition, thus providing high-quality and highly reliable voltage support for the entire distribution transformer area, perfectly meeting the core requirements of uninterrupted power supply scenarios.

[0058] In summary, this invention uses the predicted residuals of voltage data at various time points to obtain the disturbance intensity, which is used to characterize the load unpredictability of the current distribution substation operating conditions. Furthermore, it obtains a voltage deviation risk index based on the voltage distribution within the dead zone. The adjustment costs of the two modes are determined based on the disturbance intensity and the voltage deviation risk index, and the adjustment cost of the OLTC is further adjusted based on the rate of change of operating conditions. An effective adjustment mode command can be selected based on the adjustment costs of the two modes. This invention achieves dynamic and optimal allocation of voltage regulation equipment functions, transforming voltage oscillations that might otherwise be caused by equipment action conflicts into a smooth and orderly control handover process. This allows for voltage management without introducing secondary disturbances, directly meeting the core requirements of continuity and stability in uninterrupted power supply scenarios.

[0059] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0060] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for managing distribution transformer area voltage in an uninterrupted power supply scenario, characterized in that, The method includes: The active power sequence of the power system under each preset sampling period is obtained, and the prediction residual of each time point in the active power sequence is obtained using a sequence prediction algorithm. The disturbance intensity is obtained based on the volatility of the prediction residual. The voltage deviation risk index is obtained based on the distribution of voltage over a preset dead zone range under the sampling period. The rate of change of operating conditions in each sampling period is obtained based on the difference in disturbance intensity and the difference in voltage offset risk index between adjacent sampling periods. In each sampling period, the first regulation cost of OLTC and the second regulation cost of SVG are evaluated based on the magnitude of the disturbance intensity and the magnitude of the voltage offset risk index, respectively; the first regulation cost is corrected using the operating condition change rate to obtain the third regulation cost; The voltage regulation mode command is determined by comparing the third regulation cost with the second regulation cost.

2. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the prediction residual includes: For the actual active power data at each time point, the predicted active power data is obtained based on the historical active power data sequence under the preset historical time period, and the difference between the actual active power data and the predicted active power data is used as the prediction residual.

3. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the disturbance intensity includes: The standard deviation of the predicted residual is used as the disturbance intensity.

4. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the voltage offset risk index includes: The last voltage data in the sampling period is taken as the real-time voltage; the voltage offset risk index of the initial sampling period is set to 0. If the real-time voltage is within the dead zone, the voltage offset risk index of the previous sampling period is attenuated according to a preset attenuation coefficient to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage; the lower limit of attenuation is set to 0. If the real-time voltage is outside the dead zone, the nearest difference distance between the real-time voltage and the dead zone is obtained; the voltage offset risk index of the previous sampling period is increased based on the nearest difference distance to obtain the voltage offset risk index of the sampling period corresponding to the real-time voltage.

5. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the rate of change of the operating condition includes: After normalizing the disturbance intensity and voltage offset risk indicators, the normalization results are used as the feature vectors of each sampling period; the Euclidean distance between the feature vectors of adjacent sampling periods is used as the rate of change of the operating condition.

6. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 5, characterized in that, Methods for normalizing disturbance intensity and voltage offset risk indices include: For data to be normalized, the data at 95% of the corresponding dimension's data interval is used as the baseline value. Each data point to be normalized is used as the numerator, and the baseline value is used as the denominator. If the ratio is greater than 1, the normalization result is set to 1; if the ratio is not greater than 1, the ratio is used as the normalization result.

7. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the first adjustment cost includes: The disturbance intensity is weighted using a preset first weight to obtain a first weighted disturbance intensity; the voltage offset risk index is weighted using a preset second weight to obtain a first weighted voltage offset risk index; the sum of the first weight and the second weight is a positive integer 1; The adjustment amount is obtained by adjusting the fixed marginal wear cost of the OLTC based on the difference between the first weighted disturbance intensity and the first weighted voltage offset risk index, thus obtaining the first adjustment cost.

8. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the second adjustment cost includes: The disturbance intensity is weighted using a preset third weight to obtain a second weighted disturbance intensity; the voltage offset risk index is weighted using a preset fourth weight to obtain a second weighted voltage offset risk index; the sum of the third weight and the fourth weight is a positive integer 1; The adjustment amount is obtained by summing the second weighted disturbance intensity and the second weighted voltage offset risk index, and the opportunity cost of SVG in the current sampling period is adjusted to obtain the second adjustment cost.

9. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The method for obtaining the third adjustment cost includes: After normalizing the rate of change of operating conditions, add it to a positive integer 1 to obtain a correction coefficient; multiply the correction coefficient by the first adjustment cost as the third adjustment cost.

10. The method for managing distribution transformer area voltage in an uninterrupted power supply scenario according to claim 1, characterized in that, The command to determine the voltage regulation mode of the distribution area includes: If the third adjustment cost is less than or equal to the second adjustment cost, the OLTC-dominated collaborative voltage regulation mode command is selected; if the third adjustment cost is greater than the second adjustment cost, the SVG independent compensation mode is selected.

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