User side reactive compensation loss reduction calculation method, reactive compensation device and communication architecture

Abstract

The invention discloses a user side reactive compensation loss reduction calculation method, a reactive compensation device and a communication architecture, and relates to the technical field of distribution network line loss analysis. The method comprises the following steps: arranging the reactive compensation device at a compensation point between a user and a transformer area main transformer, and calculating first line impedance based on line length; the reactive power compensation device is used for performing dynamic correction by combining real-time user data to obtain second line impedance, performing weighted fusion according to confidence to obtain third line impedance, calculating line loss power before and after compensation by using the third line impedance and the real-time user data, and further obtaining loss reduction electric quantity, and comprises a sampling module, a main control module, a protection module, a communication module and a man-machine interface module, according to the reactive compensation loss reduction evaluation system, the reactive compensation loss reduction evaluation method and the reactive compensation loss reduction evaluation system, data can be acquired in real time, parameters can be calculated, and capacitor switching can be controlled, the communication architecture comprises a reactive compensation device, a transformer area concentrator and an electricity utilization information acquisition system, data uploading, management and visual analysis are supported, accurate calculation of line loss is realized, and the accuracy and reliability of reactive compensation loss reduction evaluation are improved.

Description

Technical Field

[0001] This invention relates to the field of power distribution network line loss analysis technology, specifically to a user-side reactive power compensation loss reduction calculation method, reactive power compensation device, and communication architecture. Background Technology

[0002] In the refined management of modern low-voltage distribution networks, efficient and accurate diagnosis of line losses in distribution areas and the implementation of measures to reduce line losses are core issues for ensuring the economic operation and safe and stable planning of the power system. Currently, the main means of reducing losses in 400V distribution networks is to use reactive power compensation on the user side. Its core principle is to improve the power factor on the transmission line by adjusting the reactive power of the user, thereby reducing line losses.

[0003] However, in existing technologies, the line loss of a transformer area is usually calculated by the difference between the total power supply measured by the transformer area's main meter and the total power consumption measured by all users' meters. This method can only reflect the overall line loss level of the transformer area and cannot accurately quantify the line loss contribution of individual users, nor can it assess the specific loss reduction after installing reactive power compensation devices.

[0004] Chinese invention patent (CN202511461191) discloses a method for predicting line losses in low-voltage distribution networks based on machine learning. The method predicts line losses by training a model, but it is still limited to the calculation of line losses in the entire distribution area and cannot be refined to the user level.

[0005] Chinese invention patent (CN202510957985) discloses a full-cycle cost-per-kilowatt-hour calculation model for evaluating the economics of reactive power compensation equipment. However, its focus is on the calculation of the cost recovery period, and it does not involve a precise measurement method for user-level line loss. Furthermore, the accuracy of the loss reduction calculation formula used is limited.

[0006] Therefore, there is an urgent need for an effective method that can accurately and in real time measure the line loss of individual users and compensate for losses to meet the urgent needs of refined management of distribution networks and improvement of user-side energy efficiency. Summary of the Invention

[0007] The purpose of this invention is to provide a user-side reactive power compensation loss reduction calculation method, reactive power compensation device, and communication architecture technical solution to solve the problems raised in the prior art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for calculating reactive power compensation loss reduction on the user side, comprising the following steps: S1. Install reactive power compensation devices at the compensation points on the transmission line between the user and the main transformer of the distribution area.

[0009] Deploying reactive power compensation devices can directly collect core electrical data such as three-phase voltage and current on the user side at the location, providing a real-time and accurate data source for subsequent calculations of user parameters, line impedance, and line loss power. On the other hand, the device can dynamically adjust the reactive power output based on the calculation results, achieving the goal of reducing line loss from a hardware perspective. It also provides a direct target for accurately comparing the difference in line loss before and after compensation, solving the problem that the loss reduction effect of a single user cannot be quantified when there is no compensation device in the past.

[0010] S2. Calculate the first line impedance between the user and the main transformer of the distribution area based on the transmission line length between the compensation point and the main transformer of the distribution area, and dynamically correct the line impedance parameters based on the collected real-time user data to obtain the second line impedance.

[0011] Real-time user data not only reflects the user's real-time power consumption status, but also serves as a key basis for dynamically correcting line impedance. It can dynamically match the actual operating conditions of the line and solve the problem that traditional fixed impedance parameters are easily affected by load and environmental fluctuations.

[0012] S3. Calculate the third line impedance based on the confidence level of the first and second line impedances.

[0013] By weighting the first and second line impedances with weighting coefficients, the baseline stability of the first line impedance is preserved while incorporating the real-time adaptability of the second line impedance. The weights can be adjusted according to the actual scenario to match different confidence level requirements. The resulting third line impedance is closer to the actual impedance state of the line, laying the foundation for the accuracy of subsequent line loss power calculation.

[0014] S4. Calculate the line loss power before compensation by the reactive power compensation device, the line loss power after compensation, and the user line loss based on the third line impedance and real-time user data. Based on the compensated user reactive power, active power, and precise third-line impedance, the actual line loss power after the compensation device is activated is obtained, intuitively reflecting the immediate effect of the compensation device on reducing line losses. By adding the equivalent reactive power value of the reactive power compensation device, a baseline value of line loss in the uncompensated state is obtained, which can be directly compared with the line loss power after compensation, providing a clear data reference for subsequent calculation of loss reduction.

[0015] S5. Based on the line loss power before and after compensation obtained from S4, calculate the user's line loss before and after compensation, as well as the power reduction in reactive power compensation.

[0016] By multiplying the difference in line loss power before and after compensation by the time variable, the power reduction per unit time can be integrated to obtain the total power reduction. This process transforms the difference in line loss power into specific power data, providing a direct basis for subsequent calculation of power reduction benefits in conjunction with electricity prices and for evaluating the return on investment of compensation devices.

[0017] S6. Based on the installation points of reactive power compensation devices set at different users or different branch lines, calculate the power loss reduction at each compensation point, and obtain the optimal reactive power compensation node location scheme for the line.

[0018] Furthermore, the formula for calculating the first line impedance between the user and the main transformer of the distribution area is as follows: R 参数 =L line ×θ n ; Among them, R 参数 Let L be the first line impedance. line θ is the length of the transmission line from the compensation point of the reactive power compensation device to the main transformer in the distribution area. n This is the resistance per unit length of the transmission line.

[0019] By consulting standard cable parameter tables to obtain the resistance per unit length, the basic impedance of the line can be quickly determined, ensuring the initial reliability of the impedance calculation and providing a comparison benchmark for subsequent dynamic correction. This method is suitable for scenarios with stable line parameters and minimal environmental changes.

[0020] Furthermore, the real-time user data includes at least the instantaneous values ​​of the three-phase current and three-phase voltage on the user side, and the three-phase voltage data and transmission line temperature data on the main transformer side of the distribution area. The second line impedance calculation formula for dynamically correcting the line impedance parameters is as follows: ; ; ; ; ; Among them, R 修正 U is the second line impedance. sourse This refers to the line voltage data on the main transformer side of the distribution area, where K is the temperature correction factor, and U... load P is the effective value of the line voltage. load For active power, Q load U is the reactive power, COSφ is the power factor, and U α U β I represents the voltage components in two-phase stationary coordinate systems α and β. α I βLet α represent the current components in two stationary coordinate systems α and β.

[0021] Specifically, the U α U β It is calculated from the instantaneous values ​​of three-phase voltage and current, and the formula is: ; ; By combining real-time data such as the main transformer side voltage and line temperature in the distribution area, dynamic correction is performed to obtain R. 修正 It can offset the effects of temperature drift and load fluctuation on impedance, achieve accurate matching of impedance parameters, and provide core parameters that fit the actual working conditions for line loss calculation.

[0022] By transforming the two-phase stationary coordinate system α and β, the instantaneous values ​​of the collected three-phase voltage and current are converted into effective values, power and power factor that can be directly used for line loss calculation. This lays the data foundation for subsequent impedance calculation and line loss measurement, and ensures the accuracy and consistency of parameter calculation.

[0023] Furthermore, the formula for selecting the weighted third line impedance based on the confidence level is as follows: R line =w1·R 参数 +w2·R 修正 ; Among them, R line The third line impedance is w1, where w1 is the line impedance parameter R. 参数 The weighting factor, w2 is the corrected line impedance R. 修正 The weighting coefficients.

[0024] By allocating and integrating the basic impedance and the dynamically corrected impedance using weights w1 and w2, the stability of the reference data and the adaptability of the real-time data are taken into account, thereby improving the confidence of the line impedance and further reducing the error in subsequent line loss calculations, ensuring that the line loss results are more consistent with actual operating conditions.

[0025] Furthermore, the calculation formulas for the line loss power after compensation and the line loss power before compensation by the reactive power compensation device are as follows: ; ; Among them, P 补偿后 P represents the line loss power after installing the reactive power compensation device. 补偿前 U represents the line loss power before the installation of the reactive power compensation device. load P is the effective value of the line voltage. load For active power, Q load Q represents reactive power. cap The equivalent reactive power of the capacitor is applied to the reactive power compensation device in real time; ; Where N is the total number of capacitors, Q i For each capacitor's rated capacitance, S i For each capacitor switching state, S i =1 indicates that capacitor i is connected, S i =0 indicates that capacitor i is cut off.

[0026] Based on the calculated effective value of line voltage, active power, reactive power, and weighted impedance, the line loss power before and after compensation is quantified respectively, realizing the accurate breakdown of line loss for a single user. This is the core link in subsequent loss reduction calculation and solves the problem that traditional methods cannot distinguish the difference in line loss before and after compensation for a single user.

[0027] Furthermore, the calculation formulas for line loss after compensation and line loss before compensation by the reactive power compensation device are as follows: ; ; Among them, E 补偿后线损 E represents the line loss after reactive power compensation for users. 补偿前线损 Line loss before reactive power compensation for users.

[0028] Based on dynamically updated line loss power before and after compensation, real-time integral calculation of user line loss before and after compensation is performed, solving the problem that traditional methods cannot accurately calculate the line loss of a single user.

[0029] Furthermore, the formula for calculating the reduced power consumption is as follows: ; Among them, E 降损 To reduce power loss, P 补偿后 To compensate for the subsequent line loss power, P 补偿前 To compensate for the power loss at the front line.

[0030] By multiplying the difference between the line loss power before and after compensation by time, the line loss power difference per unit time is converted into the power reduction during a specific period, thereby quantifying the reactive power compensation effect on the user side. This is combined with the power reduction benefit calculation formula Gain=λ·E. 降损 This provides core data for subsequent calculations of loss reduction benefits and evaluation of the effectiveness of compensation devices.

[0031] Specifically, the formula for the reactive power compensation node of the line with the best loss reduction benefit is: ; ; Among them, Ƞ 最优To determine the reactive power compensation node with the best loss reduction efficiency, N is the set of candidate reactive power compensation installation nodes in the distribution network, k is the number of nodes, and n i For any installation node, Gain i To achieve the loss reduction benefits of reactive power compensation at this node, λ i The real-time electricity price for the region corresponding to this node can be simplified to λ if the electricity price is uniform across the entire network. i =λ.

[0032] In the set of candidate reactive power compensation installation nodes in the distribution network, the loss reduction benefits of each node after reactive power compensation are quantified and the node with the greatest benefit is selected to achieve the optimal allocation of reactive power compensation resources to maximize the loss reduction benefits.

[0033] A reactive power compensation device, comprising: The sampling module is used to acquire real-time user data, which includes at least the instantaneous values ​​of three-phase current and three-phase voltage on the user side, and the three-phase voltage data and transmission line temperature data on the main transformer side of the distribution area. The main control module is communicatively connected to the sampling module and is used to calculate the effective value of the line voltage, active power, reactive power and power factor on the user side, calculate the line loss power after compensation and the line loss power before compensation, output reactive power compensation control commands, and control the switching of capacitors. The protection module is communicatively connected to the main control module and the sampling module, respectively, and is used to monitor the device operating parameters and the electrical parameters of the power grid side in real time. When at least one fault state of overvoltage, undervoltage, overcurrent, short circuit, and overtemperature is detected, the protection action is triggered and the reactive power compensation circuit is cut off. The communication module is connected to the main control module and is used to realize data interaction between the main control module and the background monitoring system, the intelligent terminal of the distribution area or the host computer, including uploading real-time collected data, calculated electrical parameters, line loss data, power loss reduction and device operation status information, and receiving parameter configuration instructions and compensation strategy instructions issued by the background. The human-machine interface module is used to realize the local data display and parameter setting functions of the reactive power compensation device. It displays real-time user data, calculated electrical parameters, line loss data, power loss reduction, and device operating status, and also supports users to configure the device operating parameters.

[0034] The sampling module provides basic data, the main control module realizes core control and calculation, the protection module ensures the safety of equipment and lines, the communication module realizes data interaction, and the human-machine interface module improves the convenience of operation and maintenance, solving the problems of traditional compensation devices having single functions, lack of accurate measurement and safety protection, and adapting to the needs of industrial applications.

[0035] Furthermore, the main control module is also used to calculate the reactive power to be compensated based on the target power factor and the real-time power factor, and to select the optimal switching strategy by traversing the capacitor switching combinations. The device also includes an intelligent capacitor bank, which consists of multiple capacitor banks, each with an independent rated capacity and a switching control interface.

[0036] The required reactive power compensation is calculated by reverse calculation of the target power factor, and the optimal solution is selected by traversing the capacitor switching combinations to ensure compensation accuracy. The multi-capacity configuration and independent control interface of the intelligent capacitor bank enable flexible adaptation of reactive power compensation, meet the precise compensation requirements under different load conditions, and further improve the loss reduction effect.

[0037] A communication architecture, comprising: The reactive power compensation device is used to collect real-time user data and reactive power compensation and loss reduction data, and periodically uploads them to the distribution area concentrator via high-speed power line carrier communication. The concentrator is used to collect metering data from the power supply side of the distribution area and data uploaded by all reactive power compensation devices, and uploads it to the electricity information acquisition system via wireless communication. The electricity information collection system is used to store, manage, analyze, and graphically display the data.

[0038] This involves constructing a data-connected architecture that spans the user side, distribution area side, and main station side. The reactive power compensation device uploads real-time data, the concentrator integrates and relays the data, and the electricity information collection system enables data storage, analysis, and display. This solves the problems of data transmission lag and dispersion in traditional communication architectures, providing data transmission and management support for the refined management of the distribution network.

[0039] Furthermore, it also includes a data acquisition device arranged on the side of the transformer-to-user branch line. The data acquisition device is used to collect the transformer outlet voltage and cable temperature, and transmit the data to the reactive power compensation device through high-speed power line carrier communication to support the dynamic correction of line impedance.

[0040] By collecting transformer outlet voltage and cable temperature, real-time parameters are provided for the reactive power compensation device to dynamically correct impedance, ensuring the accuracy of line impedance calculation, thereby improving the accuracy of line loss and loss reduction measurement, and enhancing the practicality and adaptability of the communication architecture.

[0041] Compared with the prior art, the beneficial effects of the present invention are: 1. Achieving precise quantification of loss reduction: This invention, by collecting real-time voltage and current data from the user side and combining line impedance parameter calculation and dynamic correction, achieves for the first time the precise breakdown of line loss power before and after compensation for a single user. Then, the power reduction is obtained through integral calculation, and the loss reduction benefit is directly quantified by combining electricity price parameters. This provides core data support for users to evaluate the return on investment of compensation devices and for power supply departments to carry out refined assessment of line loss. 2. Significantly improved accuracy in line loss calculation: On the one hand, this invention obtains the basic impedance value by consulting the standard cable parameter table to ensure the reliability of the calculation benchmark. On the other hand, it combines the voltage and line temperature data of the transformer side of the distribution area, and realizes dynamic impedance calibration by temperature coefficient correction and voltage difference back deduction, effectively offsetting the impact of temperature drift and load fluctuation on the calculation results. Finally, by weighting and integrating the two types of impedance data, the confidence of the results is further improved and the calculation error is significantly reduced. 3. Balancing control precision and operational safety: The user-side reactive power compensation device provided by this invention is not a single compensation component, but an integrated device that integrates data acquisition, algorithm execution, safety protection, information interaction and local operation. This integrated design enables the device to have both core compensation and metering functions, while also ensuring operational safety and flexibility, thus meeting the needs of industrial applications. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of a user-side reactive power compensation device according to the present invention; Figure 2 This is a schematic diagram of a user-side reactive power compensation device according to the present invention; Figure 3 This is a schematic diagram of the architecture for user-side reactive power compensation information communication according to the present invention. Figure 4 This is a table showing the measured line loss and calculated line loss after 7 consecutive days of testing according to the present invention. Figure 5 This is a schematic diagram showing the voltage drop of the 1kV polyvinyl chloride insulated power cable of the present invention used in a three-phase 380V system. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1: This example provides a method for calculating reactive power compensation loss reduction on the user side.

[0045] Specifically, taking a small and medium-sized textile factory in a certain transformer substation as the application target, the electricity information collection system data shows that the user's electricity consumption accounts for about 60% of the total electricity consumption in the substation, with an average power factor of 0.71 and a line loss rate of 4.6% in the substation. However, it is impossible to accurately determine the specific contribution of the enterprise to the line loss in the substation and its reactive power compensation potential. Based on this small and medium-sized textile factory, the user-side reactive power compensation device described in this invention is deployed to achieve accurate measurement of line loss for a single user and quantitative evaluation of loss reduction benefits.

[0046] like Figure 1 As shown, in order to achieve the above objectives, the reactive power compensation device of the present invention adopts a modular architecture of controller and intelligent capacitor bank, including 1 core controller and 3 intelligent capacitors, wherein the 3 intelligent capacitors contain a total of 6 sets of capacitors.

[0047] The core connection relationships of each module of the controller are as follows: The input terminal of the sampling module is connected to the user's incoming line side ABC three-phase line through the current transformer CT and voltage transformer PT, and the sampling point is near the user's meter box; The main control module executes reactive power compensation and line loss calculation algorithms, and establishes communication with the intelligent capacitor bank through the communication module to achieve precise control of capacitor switching. Meanwhile, the communication module is connected to the area concentrator and branch line data acquisition device via high-speed power line carrier communication. The human-machine interface features a 4-inch button-operated interactive interface, integrating real-time data display and manual parameter configuration functions.

[0048] The intelligent capacitor consists of a protection module and 6 sets of capacitors with rated capacities of [1, 2, 4, 8, 16, 32] kVar, totaling 63 kVar.

[0049] The operating logic of the device described in this invention follows a technical process of "data acquisition → compensation control → impedance parameter calculation and correction → line loss measurement → data upload". The specific working process is as follows: The device collects voltage and current in real time during a peak period of user operation to obtain the instantaneous value I of the user's three-phase current. A =30.6A, I B =131.5A, I C =160.8A and the instantaneous value of the user's three-phase voltage U A =174.9V, U B =296.0V, U C=120.0V, and calculated according to the method described in step one of the present invention: effective line voltage U1=364.60V, active power P=52.63kW, reactive power Q=55.17kVar, power factor cosφ=0.69, effective line voltage U2=398.9V and transmission line temperature data T=65.1℃ on the main transformer side of the distribution area through HPLC communication.

[0050] After data acquisition is completed, the device implements a reactive power compensation control strategy and sets the target power factor cosφ. target Given a power factor of 1.0 and a lower limit of 0.95, calculate the reactive power Q required to achieve the target power factor when the power factor cosφ is less than the lower limit. need The calculation formula is: ; Substituting the numerical values, we get Q. need It is 55.17 kVar.

[0051] Furthermore, the expected power factor cosφ is calculated iteratively for each capacitor switching combination. expect The switching combination that maximizes the power factor is selected, and the calculation formula is as follows: ; ; Among them, Q expect U1 represents the reactive power after the capacitor is connected, and Qc represents the current effective value of the line voltage. i For each capacitor's rated capacity, S i By substituting the numerical values ​​for the switching states of each capacitor, we find that switching on capacitors with rated capacities of 4kVar, 8kVar, 16kVar, and 32kVar maximizes the power factor, and the compensated reactive power Q is obtained. expect It is 0.065 kVar.

[0052] Q need The equivalent reactive power Q is corrected to the capacitor's rated voltage of 380V. correct The formula is: Q correct =(380 / U1)²·Q need Substituting the numerical values, we obtain Q. correct The value is 59.93 kVar, which is rounded to 60 kVar. Based on the rated reactive power of the capacitor bank [1,2,4,8,16,32], 60 is encoded in 8421 BCD code, resulting in [0,0,1,1,1,1]. This means that four sets of capacitors, namely 4 kVar, 8 kVar, 16 kVar, and 32 kVar, are connected.

[0053] Furthermore, impedance parameter calculation and correction are performed. Specifically, the line impedance calculation and correction process is as follows: First, the basic impedance parameters are calculated. It is known that the transmission line length from the compensation point to the main transformer in the distribution area is 0.5km, and the line type is "overhead insulated conductor, AC1kV, JKLYJ,120".

[0054] like Figure 5 As shown in the table, 120mm 2 The resistance per unit length of aluminum conductor is 0.278 Ω / km. Based on this, the basic impedance R is calculated to be 0.5km × 0.278 Ω / km = 0.139 Ω. Further, the dynamic correction impedance is calculated. First, the line temperature correction coefficient K is calculated as K = 1 + 0.0043 / ℃ × (65.1℃ - 25℃) = 1.17243. Substituting this into the dynamic correction formula of this invention, we get: ; The final weighted impedance was determined by setting the base impedance weight w1 = 0.6 and the dynamic correction impedance weight w2 = 0.4. The resulting line impedance R after weighting was then calculated. line =0.6×0.139Ω+0.4×0.143Ω=0.1406Ω.

[0055] Based on the above impedance parameters, the calculation process for line loss and loss reduction benefits is as follows: the active power of the device is 52.63kW, the reactive power before commissioning is 55.17kVar, and the reactive power after commissioning is 0.065kVar. Substituting these values ​​into the line loss calculation formula of this invention, we obtain the line loss power P before compensation. 补偿前 =6.15kW, compensated line loss power P 补偿后 =2.93kW.

[0056] The sampling module's calculation period dt is 833 μs. Substituting this into the loss reduction calculation formula of this invention, the loss reduction for the current calculation period is 7.4537 × 10⁻⁶. −7 The total loss reduction E is obtained by summing up the loss reduction in each calculation cycle within a day. 降损 The total loss reduction for the day was 37.62 kWh. Based on the daily electricity price of 0.5 yuan / kWh, the loss reduction revenue was calculated to be 0.5 × 37.62 = 16.81 yuan.

[0057] To verify the effectiveness and superiority of the method and apparatus of this invention, a comparative experiment was conducted to test the accuracy of the line loss calculation. The apparatus calculated the line loss according to the following formula: ; Among them, R line P is the line impedance calculated in real time by the device after fusion, Q is the active power measured in real time, U is the reactive power measured in real time, and U is the effective value of the line voltage measured in real time.

[0058] The control group installed high-precision meters at both ends of the transmission line near the transformer and the user, respectively, to measure the power supply E at the transformer side. 供电 And the power consumption E on the user side 用电 Actual line loss E 实测 The calculation formula is: E 实测 =E 供电 -E 用电 The results of the continuous testing over 7 days are shown in the table below. The formula for calculating the error Err is: .

[0059] like Figure 4 As shown in the comparative experimental results, the average error rate of the line loss calculation of this device is 0.45%, that is, the line loss calculation accuracy reaches the level of 0.5s.

[0060] In the application scenario of the aforementioned small and medium-sized textile factories, the five core branch lines N={n1,n2,n3,n4,n5} of the transformer area where the textile factory is located are taken as the research object, where n3 is the compensation node corresponding to the textile factory, and the remaining nodes correspond to other industrial users, commercial users and residential clusters in the transformer area, respectively. The specific implementation process is as follows: The core parameters of five candidate nodes are acquired simultaneously through the area concentrator and branch line data acquisition device: The transmission line lengths are n1=0.8km, n2=0.5km, n3=0.5km, n4=1.1km, and n5=0.7km. Unit length resistance θ n All node lines are of type "overhead insulated conductor, AC1kV, JKLYJ, 120". From the table, θ is... n =0.278Ω / km; Real-time electricity price λ i The λ for industrial user nodes n1, n3, and n4 is 0.65 yuan / kWh, the λ for commercial user node n2 is 0.72 yuan / kWh, and the λ for residential cluster node n5 is 0.55 yuan / kWh. According to the formula for the reactive power compensation node of the line with the best loss reduction effect: ; Among them, Ƞ 最优 To determine the reactive power compensation node with the best loss reduction efficiency, N is the set of candidate reactive power compensation installation nodes in the distribution network, k is the number of nodes, and n i For any installation node, Gain i To achieve the loss reduction benefits of reactive power compensation at this node, λ i This represents the real-time electricity price for the region corresponding to this node.

[0061] The calculated loss reduction benefits for each node are: n1 = 19.40 yuan, n2 = 15.35 yuan, n3 = 24.45 yuan, n4 = 20.92 yuan, and n5 = 10.21 yuan.

[0062] Compare the Gain of each node i The value shows that the loss reduction benefit of node n3 is the maximum, which is 24.45 yuan. Therefore, n3 is determined to be the optimal reactive power compensation node for this transformer area.

[0063] In summary, the application verification of this embodiment shows that the reactive power compensation device of the present invention can achieve accurate measurement of line loss and loss reduction for a single user, with an error of ≤±0.45%. The present invention effectively solves the problems of inaccurate line loss location and difficulty in quantifying loss reduction benefits in traditional technologies, and provides reliable technical support for the evaluation of investment return on reactive power compensation on the user side and the refined management of line loss in power supply companies' distribution areas.

[0064] Example 2: This example provides a reactive power compensation device that can monitor the electrical parameters on the user side in real time and dynamically adjust the reactive power compensation amount to achieve the optimal compensation effect.

[0065] like Figure 2 As shown, it specifically includes the following modules: Sampling Module: This module is responsible for real-time acquisition of the instantaneous three-phase current I on the user side. A I B I C and the instantaneous value of three-phase voltage U A U B U C And the three-phase voltage data U on the main transformer side of the distribution area. sourse and transmission line temperature data L line .

[0066] The sampling module uses high-precision sensors to accurately acquire data, providing a reliable basis for subsequent calculations.

[0067] Main control module: Communicates with the sampling module. The main control module calculates the effective value U of the line voltage on the user side based on the sampled data. load Active power P load Reactive power Q load and power factor COSφ.

[0068] Meanwhile, the main control module is also responsible for calculating the line loss power before and after compensation, and calculating the reactive power to be compensated based on the target power factor and the real-time power factor. By traversing the capacitor switching combinations, the main control module selects the optimal switching strategy, outputs reactive power compensation control commands, and controls the switching of the intelligent capacitor bank.

[0069] Intelligent capacitor bank: It consists of multiple sets of capacitors with independent rated capacity and switching control interface. According to the instructions of the main control module, the intelligent capacitor bank can dynamically adjust the number of capacitors put into operation in order to achieve accurate compensation of reactive power.

[0070] Protection module: It is connected to the main control module and the sampling module respectively. The protection module monitors the operating parameters of the device and the electrical parameters of the power grid in real time.

[0071] When fault conditions such as overvoltage, undervoltage, overcurrent, short circuit, and overtemperature are detected, the protection module immediately triggers protection actions, cuts off the reactive power compensation circuit, and ensures the safe operation of the equipment and the power grid.

[0072] Communication module: It communicates with the main control module and is responsible for enabling data interaction between the main control module and the background monitoring system, the intelligent terminal of the distribution area, or the host computer.

[0073] The communication module uploads real-time acquired data, calculated electrical parameters, line loss data, power loss reduction, and device operating status information via high-speed power line carrier communication HPLC or wireless communication, and receives parameter configuration instructions and compensation strategy instructions from the background.

[0074] Human-machine interface module: Provides local data display and parameter setting functions.

[0075] The human-machine interface module displays real-time user data, calculated electrical parameters, line loss data, power loss reduction, and device operating status. It also supports users in configuring device operating parameters, improving the ease of use and maintainability of the device.

[0076] The reactive power compensation device in this embodiment effectively improves the power factor of the power grid and reduces line losses by real-time monitoring and accurate compensation of reactive power on the user side. At the same time, the device has complete protection functions and communication interfaces, ensuring the safe operation of the equipment and the power grid, and providing strong support for the intelligent management of the power grid.

[0077] Example 3: This example provides a communication architecture suitable for reactive power compensation devices, aiming to achieve efficient and reliable data transmission between the device and the back-end system, and to provide strong support for the intelligent management of the power grid.

[0078] like Figure 3 As shown, it specifically includes the following parts: Reactive power compensation device: As a data acquisition and execution unit, the reactive power compensation device is responsible for collecting electrical parameters related to reactive power compensation from the user side in real time, and obtaining information such as line loss data and power reduction through the built-in calculation module.

[0079] Meanwhile, the reactive power compensation device periodically uploads data to the distribution area concentrator via high-speed power line carrier communication HPLC.

[0080] Concentrator: Located on the transformer side of the distribution area, the concentrator is responsible for collecting metering data from the power supply side of the distribution area as well as data uploaded by all reactive power compensation devices.

[0081] Using 4G wireless communication, the concentrator uploads data to the electricity information collection system, enabling centralized data storage and processing.

[0082] Electricity Information Collection System: As a background data processing and analysis platform, the electricity information collection system is responsible for storing, managing, and analyzing data from the concentrators, and displaying key information such as line loss distribution and loss reduction effect through a graphical interface.

[0083] This provides power supply departments with intuitive decision support, helps optimize reactive power compensation strategies, and improves grid operation efficiency.

[0084] Optional, data acquisition device: A data acquisition device is installed on the side from the transformer in the distribution area to the user branch line to collect key parameters such as transformer outlet voltage and cable temperature. Through high-speed power line carrier communication (HPLC), the data acquisition device transmits the data to the reactive power compensation device to support dynamic correction of line impedance and further improve the accuracy of line loss calculation.

[0085] The communication architecture in this embodiment enables data interaction between the reactive power compensation device and the back-end system through high-speed and reliable communication, providing strong support for the intelligent management of the power grid.

[0086] Meanwhile, the optional data acquisition device further improves the accuracy of line loss calculation, which helps power supply departments to more accurately grasp the power grid operation status, optimize reactive power compensation strategies, reduce line losses, and improve the economy and stability of the power grid.

[0087] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for calculating reactive power compensation loss reduction on the user side, characterized in that, Includes the following steps: S1. Install reactive power compensation devices at the compensation points on the transmission line between the user and the main transformer of the distribution area. S2. Calculate the first line impedance between the user and the main transformer of the distribution area based on the transmission line length between the compensation point and the main transformer of the distribution area, and dynamically correct the line impedance parameters based on the collected real-time user data to obtain the second line impedance. S3. Calculate the third line impedance based on the confidence level of the first and second line impedances. S4. Calculate the line loss power before compensation by the reactive power compensation device, the line loss power after compensation, and the user line loss based on the third line impedance and real-time user data. S5. Based on the line loss power before and after compensation obtained from S4, calculate the user's line loss before and after compensation, as well as the power reduction of reactive power compensation. S6. Based on the installation points of reactive power compensation devices set at different users or different branch lines, calculate the power loss reduction at each compensation point, and obtain the optimal reactive power compensation node location scheme for the line.

2. The user-side reactive power compensation loss reduction calculation method according to claim 1, characterized in that: The formula for calculating the first line impedance between the user and the main transformer of the distribution area is: R 参数 =L line ×θ n ; Among them, R 参数 Let L be the first line impedance. line θ is the length of the transmission line from the compensation point of the reactive power compensation device to the main transformer in the distribution area. n This is the resistance per unit length of the transmission line.

3. The user-side reactive power compensation loss reduction calculation method according to claim 2, characterized in that: The real-time user data includes at least the instantaneous values ​​of three-phase current and three-phase voltage on the user side, and the three-phase voltage data and transmission line temperature data on the main transformer side of the distribution area. The second line impedance calculation formula for dynamically correcting the line impedance parameters is as follows: ； ； ； ； ； Among them, R 修正 U is the second line impedance. sourse This refers to the line voltage data on the main transformer side of the distribution area, where K is the temperature correction factor, and U... load P is the effective value of the line voltage. load For active power, Q load U is the reactive power, COSφ is the power factor, and U α U β I represents the voltage components in two-phase stationary coordinate systems α and β. α I β Let α represent the current components in two stationary coordinate systems α and β.

4. The user-side reactive power compensation loss reduction calculation method according to claim 3, characterized in that: The formula for selecting the weighted third line impedance based on the confidence level is as follows: R line =w1·R 参数 +w2·R 修正 ; Among them, R line The third line impedance is w1, where w1 is the line impedance parameter R. 参数 The weighting factor, w2 is the corrected line impedance R. 修正 The weighting coefficients.

5. The user-side reactive power compensation loss reduction calculation method according to claim 4, characterized in that: The formula for calculating the line loss power after compensation and the line loss power before compensation using a reactive power compensation device is as follows: ； ； Among them, P 补偿后 P represents the line loss power after installing the reactive power compensation device. 补偿前 U represents the line loss power before the installation of the reactive power compensation device. load P is the effective value of the line voltage. load For active power, Q load Q represents reactive power. cap The equivalent reactive power of the capacitor is applied to the reactive power compensation device in real time; The formulas for calculating line loss after compensation and line loss before compensation by the reactive power compensation device are as follows: ； ； Among them, E 补偿后线损 E represents the line loss after reactive power compensation for users. 补偿前线损 Line loss before reactive power compensation for users.

6. The user-side reactive power compensation loss reduction calculation method according to claim 5, characterized in that: The formula for calculating the reduced power consumption is as follows: ； Among them, E 降损 To reduce power loss, P 补偿后 To compensate for the power loss after line loss, P 补偿前 To compensate for the power loss at the front line.

7. A reactive power compensation device, characterized in that: The user-side reactive power compensation loss reduction calculation method applied to claims 1-6 includes: The sampling module is used to acquire real-time user data, which includes at least the instantaneous values ​​of three-phase current and three-phase voltage on the user side, and the three-phase voltage data and transmission line temperature data on the main transformer side of the distribution area. The main control module is communicatively connected to the sampling module and is used to calculate the effective value of the line voltage, active power, reactive power and power factor on the user side, calculate the line loss power after compensation and the line loss power before compensation, output reactive power compensation control commands, and control the switching of capacitors. The protection module is communicatively connected to the main control module and the sampling module, respectively, and is used to monitor the device operating parameters and the electrical parameters of the power grid side in real time. When at least one fault state of overvoltage, undervoltage, overcurrent, short circuit, and overtemperature is detected, the protection action is triggered and the reactive power compensation circuit is cut off. The communication module is connected to the main control module and is used to realize data interaction between the main control module and the background monitoring system, the intelligent terminal of the distribution area or the host computer, including uploading real-time collected data, calculated electrical parameters, line loss data, power loss reduction and device operation status information, and receiving parameter configuration instructions and compensation strategy instructions issued by the background. The human-machine interface module is used to realize the local data display and parameter setting functions of the reactive power compensation device. It displays real-time user data, calculated electrical parameters, line loss data, power loss reduction, and device operating status, and also supports users to configure the device operating parameters.

8. The reactive power compensation device according to claim 7, characterized in that, The main control module is also used to calculate the reactive power to be compensated based on the target power factor and the real-time power factor, and to select the optimal switching strategy by traversing the capacitor switching combinations. The device also includes an intelligent capacitor bank, which consists of multiple capacitor banks, each with an independent rated capacity and a switching control interface.

9. A communication architecture applied to the reactive power compensation device of claim 8, characterized in that, include: The reactive power compensation device is used to collect real-time user data and reactive power compensation and loss reduction data, and periodically uploads them to the distribution area concentrator via high-speed power line carrier communication. The concentrator is used to collect metering data from the power supply side of the distribution area and data uploaded by all reactive power compensation devices, and uploads it to the electricity information acquisition system via wireless communication. The electricity information collection system is used to store, manage, analyze, and graphically display the data.

10. The communication architecture according to claim 9, characterized in that, It also includes a data acquisition device located on the branch line from the transformer to the user. The data acquisition device is used to collect the transformer outlet voltage and cable temperature, and transmit the data to the reactive power compensation device through high-speed power line carrier communication to support the dynamic correction of line impedance.

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