Distributed power supply grid connection line loss monitoring method

Abstract

The invention discloses a distributed power supply grid connection line loss monitoring method, and belongs to the technical field of distributed power supply grid connection line loss monitoring. The distributed power supply grid connection line loss monitoring method comprises the following steps: S1, for the distributed power supply grid connection line loss monitoring method, an early-stage preparation module in a pre-support is arranged; the monitoring system is a basis for all monitoring work, and comprises a defined monitoring range, collected parameters and calibration equipment; and S2, after the preparation of the early-stage preparation module is completed, an adaptive method is selected through a monitoring method module in core execution according to the metering point completeness and the scene complexity. According to the distributed power supply grid connection line loss monitoring method, the arranged early-stage preparation module is the basis of all monitoring work, the defined monitoring range, collected parameters and calibration equipment provide'physical boundary, data basis and hardware guarantee 'for the core monitoring method, and the parameter precision directly affects the accuracy of the monitoring result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of distributed power grid-connected line loss monitoring, in particular to a distributed power grid-connected line loss monitoring method. BACKGROUND

[0002] With the promotion of the current double carbon target, the proportion of distributed power used in the distribution network is increasing year by year, and the installed capacity of distributed photovoltaic power in China accounts for a large proportion. Such power has intermittent output, with high intra-day photovoltaic output fluctuation amplitude, dispersed access nodes, and the characteristics of multiple grid-connected points on a single line, which changes the traditional radial power flow of the distribution network to the existing multi-source bidirectional power flow, and puts forward higher requirements for the real-time and accuracy of line loss monitoring.

[0003] Although the prior art can perform monitoring work, it is inconvenient to control the monitoring range during the work process, it is difficult to effectively collect parameters for calculation, and calibration work is difficult to perform, which affects the stability of the monitoring work, and it is not convenient to measure the grid-connected line loss monitoring in complex scenarios.

[0004] In view of the above problems, it is urgent to make innovative design on the basis of the original distributed power grid-connected line loss monitoring method. SUMMARY

[0005] The purpose of the present application is to provide a distributed power grid-connected line loss monitoring method to solve the problem of inconvenient control of the monitoring range during the work process, difficulty in effectively collecting parameters for calculation, and calibration work affecting the stability of the monitoring work, and inconvenience in measuring the grid-connected line loss monitoring in complex scenarios.

[0006] To achieve the above purpose, the present application provides the following technical scheme: a distributed power grid-connected line loss monitoring method, the distributed power grid-connected line loss monitoring method comprising the following steps:

[0007] Step 1: For the distributed power grid-connected line loss monitoring method, a pre-preparation module in the front support is set to be the basis for all monitoring work, which defines the monitoring range, collects parameters, and calibrates equipment;

[0008] Second step: After the preparation module is prepared, the monitoring method module in the core execution is selected according to the metering point completeness and scene complexity, and the measurement method is used for the basic scene, the model estimation method is used for the sparse scene, the intelligent fusion method meets the high-precision demand, the parameter input of the preparation module is received, the monitoring data is output to the result analysis module, and the calculation of different scenes is carried out with the special scene adaptation module in the scene completion, and then the monitoring result analysis and optimization closed loop module is carried out for result analysis and synchronous optimization closed loop module;

[0009] Third step: The special scene adaptation module is an extension of the core method, which adjusts the steps and parameters of the core method for low-voltage, multi-power sharing line and other special situations to ensure that the monitoring covers all scenes and avoids "one size fits all";

[0010] Fourth step: The monitoring result analysis and optimization closed loop module is the final landing link of monitoring, which receives the results of the core monitoring method, proposes optimization measures through trend analysis and abnormal positioning, and feeds back the optimized parameters such as conductor cross-sectional area adjustment and power factor after the installation of reactive power compensation device to the preparation module to update the monitoring benchmark and form a closed loop of "monitoring-analysis-optimization-re-monitoring".

[0011] Preferably, the preparation module further comprises determining the monitoring range and boundary, collecting and verifying the basic parameters, and selecting and calibrating the monitoring equipment, and the core reference point is determined in the determination of the monitoring range and boundary, and the "grid connection point" of the distributed power supply is taken as the core benchmark point, which is the connection node of the power supply and the power grid and also the starting point or key dividing point of the monitoring range. The starting and ending nodes are extended to the "upper grid connection point" on the upper grid side and to the "load access point" on the lower load side, the complete line section of "start-end" is determined, the line type is distinguished to determine whether the monitoring line is a "dedicated line" or a "shared line", and the key information is recorded. The voltage level, physical length and starting and ending node number of the monitoring line are recorded in writing; the parameter collection list is determined in the collection and verification of the basic parameters, and the data is collected through multiple channels. The original parameters of the line are obtained through design drawings, the meter accuracy, sampling frequency and other information are obtained through equipment nameplates, the dynamic parameters such as line operating temperature and actual power factor are obtained through on-site measurement, and the parameter accuracy is verified twice, and the parameter document is arranged; the equipment is selected according to the scene in the selection and calibration of the monitoring equipment, and the compatibility of the equipment is confirmed, and the calibration of the equipment is completed in advance, so that the equipment installation and debugging can ensure that the equipment can collect and upload data stably according to the set period, without packet loss and transmission error.

[0012] Preferably, the core monitoring method module further comprises different methods for monitoring execution, wherein the metering measurement method and the model estimation monitoring method are suitable for different scenarios.

[0013] Preferably, the metering measurement method is deployed at the physical layer by scientifically arranging monitoring points, and during the deployment process, the number of monitoring points is determined and the monitoring content of each monitoring point is specified, and through standardized equipment installation, data deviation caused by wiring errors is avoided, and the terminal and the meter are firmly connected, and waterproof, anti-interference protection is done, so that through periodic data collection and preprocessing, data layer processing is performed to determine the collection period, collect raw data and data preprocessing.

[0014] Preferably, after the metering measurement method scientifically arranges monitoring points and collects and preprocesses data by period, it performs calculation layer execution by step-by-step calculation of line loss, and calculates single-period input or output total power, and calculates single-period power loss, period total line loss, line loss rate and segmented line loss calculation (long line), and after the calculation is completed, the monitoring results are checked and corrected, and the results are optimized, so that the error source is analyzed and the total error power is calculated, and then the line loss result is corrected and the result rationality is checked.

[0015] Preferably, the model estimation monitoring method is suitable for metering point sparse scenarios, and the modeling layer is prepared by building a line parameter model, and the core modeling parameters focus on line resistance and reactance, ignore conductance, and calculate the line resistance at standard temperature: according to the line material, length, cross-sectional area, use the formula R O =ρL / S to calculate, and correct the resistance at the actual operating temperature, and simplify the calculation of line reactance, and after the line parameter model is built, the key operating data is collected, the collection content is determined, and there is no need to arrange end or segmented meters, only the total power (active P in , reactive Q in ) and line operating temperature (T) at the head end are collected, the data collection cost is reduced, and then the collection period is set in in The model estimation has a certain error, so the collection period needs to be slightly shorter than the metering measurement method to ensure that the data can reflect the power fluctuation and reduce the estimation deviation, so that the data is recorded and arranged, and the data is recorded in the format of "collection time-P

[0016] ​Preferably, the model estimation monitoring method estimates the line loss by steps after the line parameter model is built and the key operation data is collected, and the first end apparent power is calculated stably, and the line phase current is derived, and the single period power loss is calculated, the cumulative period total line loss is calculated, and the estimated line loss rate is calculated, and the model estimation error is corrected after the calculation, the calibration benchmark is selected, if there are a small number of metering points, the measured line loss of the metering point is used as the calibration benchmark, and if there is no metering point, the historical measured line loss of the same type line is used as the benchmark, so as to calculate the correction coefficient and correct the estimation result.

[0017] Preferably, the special scene adaptive monitoring module can monitor different scenes through low-voltage distributed power and multi-power sharing line monitoring, and in the low-voltage distributed power monitoring process, the monitoring range and the monitoring point are adjusted to define the monitoring range and simplify the monitoring point arrangement, and the parameters and the collection mode are adjusted to adjust the line parameter calculation and the collection period, that is, the line loss calculation logic can be adjusted, the formula ΔP=I 2 R is used for single-phase line calculation, and the formula ΔW=ΔP×t (t is the running time, such as 24 hours) is used for period line loss calculation, and the line loss rate η=(ΔW / total output power of inverter)×100%.

[0018] Preferably, the multi-power sharing line monitoring optimizes the monitoring point arrangement, increases the grid-connected point monitoring point and retains the segmented monitoring point, collects the multi-power collaborative data for synchronous data collection and power operation state recording, and performs superposition loss calculation for calculating single-power single line loss and superimposed interaction loss and total loss summary.

[0019] Preferably, the monitoring result analysis and optimization closed loop module analyzes the monitoring result in depth, performs trend analysis and abnormal positioning, and forms a closed loop by landing optimization measures and tracking optimization effect, so that after the optimization measures are implemented, the line loss rate before and after optimization is compared by continuing to monitor for 1-3 months according to the original monitoring method, the effectiveness of the measures is verified, and the optimized line parameters are fed back to the "preparation module" to update the basic parameter summary table as a new benchmark for subsequent monitoring, forming a "monitoring-analysis-optimization-remonitoring" closed loop.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1. The distributed power grid-connected line loss monitoring method, the pre-preparation module provided is the basis for all monitoring work, the defined monitoring range, collected parameters and calibrated equipment provide "physical boundary, data basis and hardware guarantee" for the core monitoring method, and the parameter precision directly affects the accuracy of the monitoring result.

[0022] 2. The distributed power supply grid-connected line loss monitoring method, the monitoring method module is the core execution link, the method is selected according to the metering point completeness and the scene complexity, the parameter input of the previous preparation module is received, and the monitoring data is output to the result analysis module;

[0023] 3. The distributed power supply grid-connected line loss monitoring method, the special scene adaptation module is the extension of the core method, for special conditions such as low-voltage, multi-power supply shared line, the steps and parameters of the core method are adjusted to ensure that the monitoring covers all scenes and avoids 'one size fits all'; Further, the monitoring result analysis and optimization closed loop module is the final landing link of monitoring, receives the result of the core monitoring method, proposes optimization measures through trend analysis and abnormal positioning, and feeds back the optimized parameters to the previous preparation module to update the monitoring benchmark, forming a'monitoring-analysis-optimization-remonitoring' closed loop. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a three-dimensional structure schematic diagram of the distributed power supply grid-connected line loss monitoring method of the application;

[0025] Figure 2 It is a three-dimensional structure schematic diagram of the previous preparation module of the application;

[0026] Figure 3 It is a three-dimensional structure schematic diagram of the core monitoring method module of the application;

[0027] Figure 4 It is a three-dimensional structure schematic diagram of the metering measurement method of the application;

[0028] Figure 5 It is a three-dimensional structure schematic diagram of the power supply monitoring of the model estimation monitoring method of the application;

[0029] Figure 6 It is a three-dimensional structure schematic diagram of the low-voltage distributed power supply of the application;

[0030] Figure 7 It is a three-dimensional structure schematic diagram of the multi-power supply shared line monitoring of the application

[0031] Figure 8 It is a three-dimensional structure schematic diagram of the monitoring result analysis and optimization closed loop module of the application. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0033] Please refer to Figures 1-8 The application provides a technical solution: a distributed power grid-connected line loss monitoring method, which comprises the following steps:

[0034] First step: for the distributed power grid-connected line loss monitoring method, the pre-preparation module in the front support set is used as the basis for all monitoring work, which defines the monitoring range, collected parameters, and calibrated equipment;

[0035] Second step: after the preparation of the pre-preparation module, the monitoring method module in the core execution is used to select the appropriate method according to the metering point completeness and scene complexity, and to use the metering measurement method for basic scenes, the model estimation method for sparse scenes, and the intelligent fusion method for high-precision requirements. At the same time, the parameter input of the pre-preparation module is received, the monitoring data is output to the result analysis module, and the calculation of different scenes is performed with the special scene adaptation module in the scene completion. Then, the monitoring result analysis and optimization closed loop module is used for result analysis and synchronous optimization closed loop module;

[0036] Third step: the special scene adaptation module is an extension of the core method, which is used to adjust the steps and parameters of the core method for low-voltage, multi-power shared line and other special situations, to ensure that the monitoring covers all scenes and avoids "one-size-fits-all";

[0037] Fourth step: the monitoring result analysis and optimization closed loop module is the final landing link of the monitoring, which receives the results of the core monitoring method, proposes optimization measures through trend analysis and abnormal positioning, and feeds back the optimized parameters such as conductor cross-sectional area adjustment and power factor after the installation of reactive power compensation devices to the pre-preparation module to update the monitoring benchmark, forming a "monitoring-analysis-optimization-remonitoring" closed loop.

[0038] The pre-preparation module further includes determining the monitoring range and boundary, collecting and verifying basic parameters, and selecting and calibrating monitoring equipment, and in the determination of the monitoring range and boundary, the "grid-connected point" of the distributed power supply is determined as the core reference point, which is the connection node of the power supply and the power grid and is also the starting point or key dividing point of the monitoring range, and the extension to the "upper grid connection point" on the upper grid side and the extension to the "load access point" on the lower load side are defined, the complete line segment from the "starting point" to the "ending point" is determined, and the line type is distinguished to determine whether the line is a "dedicated line" or a "shared line", and key information is recorded, and the voltage level, physical length, and starting and ending node numbers of the monitoring line are recorded in writing; in the collection and verification of basic parameters, the parameter collection list is determined, data is collected through multiple channels, the original parameters of the line are obtained through design drawings, the meter accuracy, sampling frequency, and other information are obtained through the equipment nameplate, the dynamic parameters such as line operating temperature and actual power factor are obtained through on-site measurement, and the accuracy of the parameters is verified twice, and the parameter documents are arranged; in the selection and calibration of monitoring equipment, the equipment is selected according to the scene, and the compatibility of the equipment is confirmed, and the calibration of the equipment is completed in advance, so that the installation and debugging of the equipment ensure that the equipment can stably collect and upload data according to the set period without packet loss or transmission errors.

[0039] The core monitoring method module further includes different methods for monitoring execution, wherein the metering measurement method and the model estimation monitoring method are suitable for different scenes.

[0040] The metering measurement method deploys the monitoring points through scientific arrangement, and in the deployment process, the number of monitoring points is determined and the monitoring content of each monitoring point is determined, and the installation of the equipment is standardized to avoid data deviation caused by wiring errors, and the wiring between the collection terminal and the meter is firm, and waterproof and anti-interference protection is done, so that the data layer processing is performed through periodic collection and preprocessing of data, so as to determine the collection period, collect original data, and preprocess data.

[0041] After the metering measurement method scientifically arranges the monitoring points and periodically collects and preprocesses the data, the line loss is calculated in steps, and the calculation layer is executed, the total power input or output in a single period is calculated, the single-period power loss, the total line loss power in a period, the line loss rate, and the segmented line loss calculation (for long lines) are calculated, and after the calculation is completed, the monitoring results are verified and corrected, and the results are optimized, so that the error source is analyzed and the total error power is calculated, and the line loss results are corrected and the reasonableness of the results is verified.

[0042] The model estimation monitoring method is suitable for the metering point sparse scene, a line parameter model is built in the modeling layer, and the core modeling parameters focus on the line resistance and reactance, and the conductance is ignored, and the line resistance at the standard temperature is calculated: according to the line material, length, cross-sectional area, the formula RO = pL / S calculation, and correct the resistance at the actual operating temperature, and simplify the calculation of line reactance, and after the completion of the line parameter model, the key operation data is collected, the collection content is determined, and there is no need to arrange the end or segmented meter, only the total power (active P in , reactive Q in ) and line operating temperature (T) at the head are collected, the data collection cost is reduced, and then the collection period is set to be slightly shorter than the measurement method, to ensure that the data can reflect the power fluctuation and reduce the estimation deviation, so as to record and arrange the data, and record the data in the format of "collection time-P in -Q in -T", to ensure that the reactive power, temperature data and active power are collected synchronously.

[0043] After the completion of the line parameter model and the simplified collection of key operation data, the model estimation monitoring method estimates the line loss by steps, calculates the apparent power at the head, and derives the line current. After completion, the single period power loss is calculated, the cumulative period total line loss is calculated, and the estimated line loss rate is calculated. After calculation, the model estimation error is corrected, the calibration reference is selected, if there are a small number of measurement points, the measured line loss of the measurement point is used as the calibration reference, and if there are no measurement points, the historical measured line loss of the same type line is used as the reference, so as to calculate the correction coefficient and correct the estimation result.

[0044] The special scene adaptation monitoring module can monitor different scenes through low-voltage distributed power supply and multi-power sharing line monitoring. In the process of low-voltage distributed power supply monitoring, the monitoring range and monitoring points are adjusted to define the monitoring range and simplify the monitoring point arrangement, and the parameters and collection methods are adjusted to adjust the line parameter calculation and adjust the collection period. The line loss calculation logic can be adjusted, the formula ΔP=I 2 R is used for single-phase line calculation, and the formula ΔW=ΔP×t (t is the running time, such as 24 hours) is used for period line loss calculation, and the line loss rate η= (ΔW / total output power of inverter) ×100%.

[0045] The multi-power sharing line monitoring optimizes the monitoring point arrangement, increases the grid-connected point monitoring point and retains the segmented monitoring point, collects the multi-power coordination data, synchronously collects the data and records the power supply operation state, and performs superposition loss calculation to calculate the single-power single line loss and the superimposed interaction loss and total loss summary.

[0046] The monitoring results analysis and optimization closed-loop module deeply analyzes monitoring results, performs trend analysis and anomaly location, and implements optimization measures to form a closed loop. It formulates targeted optimization measures and tracks the optimization effect. After the optimization measures are implemented, monitoring continues for 1-3 months using the original monitoring method. The line loss rate before and after optimization is compared to verify the effectiveness of the measures, and the monitoring benchmark is updated. The optimized line parameters are fed back to the "preliminary preparation module" to update the basic parameter summary table as a new benchmark for subsequent monitoring, forming a closed loop of "monitoring-analysis-optimization-re-monitoring".

[0047] The metering and measurement method is suitable for scenarios with complete metering points. Monitoring points should be arranged according to the principle of having monitoring points at the beginning (input side), the end (output side), and segment nodes to ensure "electricity conservation" verification. Specifically, at the beginning monitoring point (node ​​A): a main meter + DTU is installed to monitor "wind power output P". DG / Battery capacity (W) DG "+" Upper-level power grid input P grid / Battery capacity (W) grid ", that is, the total input power P in =P DG +P grid Next, at the end-point monitoring point (node ​​B): install an on-grid meter + DTU to monitor the "on-grid power P". on / Battery capacity (W) on ”;

[0048] Furthermore, at the load-side monitoring point (node ​​C): a load meter is installed to monitor the "self-consumption load P". load / Battery capacity (W) load "; and segmented monitoring point (node ​​D): install segmented meters to monitor "segmented power P" section (Used for long-line loss positioning)

[0049] Data collection can then be performed, with the collection cycle adapted to wind power output fluctuations, typically 15 minutes per instance, for a collection cycle t; the data collection content includes: collection time P. DG (MW)P grid (MW)P on (MW)P load (MW) Line temperature T (°C), and after data preprocessing to remove outliers, the unit is unified to kW. Line loss monitoring calculation is then performed. Based on the core formula (based on power loss accumulation + power difference dual verification): the real-time power loss (single time period) formula is calculated as ΔP. i =P in i-(P on i+P load i), and the periodic power loss is calculated as ΔW=(ΣP in i×t)-(ΣPon i×t+ΣP load i×t)=W in -W out

[0050] Therefore, the line loss rate is calculated as η = (ΔW / W) in )×100%, for segmented line loss location (long lines): ΔP section =P in iP section i, and perform digital calculations to calculate the cumulative total input power for the day using the formula ΣP in i=Σ(P DG i+P grid i), and the formula for calculating the total output power accumulated on that day is Σ(P on i+P load i)

[0051] The monitoring results are then verified, with the verification standards being that the meter error is ≤ ±0.2% and the deviation of the line loss rate from the design value (110kV line design line loss rate 1.5%-3%) is ≤ ±0.5%.

[0052] The core of the model-based estimation and monitoring method is "parameter modeling, power flow simulation, and cumulative loss monitoring." It does not require dense data point deployment; instead, it dynamically monitors line losses through a model and models core parameters: based on the physical characteristics of the line, it constructs a "resistance and reactance" model, and the key parameters are calculated as follows:

[0053] The standard temperature circuit resistance is calculated as R. O =ρL / S, and the actual temperature-corrected resistance is calculated as R=R O ×[1+α(TT O [ ], and collect content, and only need to collect the total power at the head end (P )], and collect the content. in Q in Operating temperature (T), no end / segment metering required, data acquisition cycle 30 minutes / time, and data acquisition example P. in Q in 、T.

[0054] The core formula (based on power flow calculation and loss accumulation) includes the apparent power calculation as S. in =√(P in ²+Q in 2 The phase current of the line is calculated as follows: And the power loss in a single time period is calculated as ΔP i =3I 2 R, and the periodic bus loss is calculated as ΔW model =Σ(ΔP i ×t i), and the monitored line loss rate is calculated as η. model =(ΔW model / W in )×100%

[0055] After digital calculation, temperature correction is performed. The correction logic is to calibrate the model based on a small amount of metering data (such as one meter at the beginning and one at the end). The correction coefficient k = actual line loss / estimated line loss of the model.

[0056] Special scenario adaptation monitoring modules are used to monitor low-voltage distributed power sources and make core adjustments. The lines are a mix of single-phase and three-phase with high resistance. The monitoring points focus on the "inverter output - user meter".

[0057] Monitoring formula (single-phase line): ΔP=I 2 R (no need for ×3), U n =0.22kV / 0.38kV, and multi-power source shared line monitoring is carried out. The monitoring logic is based on the "power superposition principle". The line loss after the superposition of the output of each power source is simulated by power flow calculation software. The monitoring points are arranged at the beginning and end of the shared line and the grid connection point of each power source.

[0058] Simplified formula: ΔW total =ΔW1+ΔW2+ΔW inter (ΔW1 and ΔW2 are single power supply line losses, ΔW) inter (For superimposed interaction loss).

[0059] The monitoring results analysis and optimization closed-loop module first performs trend analysis: comparing daily or monthly line loss rates to determine the correlation between line loss and output, load, and temperature, and then locates anomalies: using segmented monitoring data to locate high-loss line segments; then, it implements optimization measures, such as increasing conductor cross-sectional area, installing reactive power compensation devices, and optimizing grid connection when line loss is high.

[0060] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for distributed power grid-connected line loss monitoring, characterized in that, The distributed power grid-connected line loss monitoring method comprises the following steps: S1: For the distributed power grid-connected line loss monitoring method, the pre-preparation module in the front support is set up to provide the basis for all monitoring work, including the defined monitoring range, collected parameters, and calibrated equipment; S2: After the pre-preparation module is prepared, the monitoring method module in the core execution is used to select the appropriate method according to the metering point completeness and scene complexity, and to give priority to the metering measurement method for the basic scene, the model estimation method for the sparse metering scene, and the intelligent fusion method for the high-precision demand. At the same time, the parameter input from the pre-preparation module is output to the result analysis module, and the calculation of different scenes is performed with the special scene adaptation module in the scene completion. Then, the monitoring result analysis and optimization closed loop module is used for result analysis and synchronous optimization closed loop module; S3: The special scene adaptation module is an extension of the core method, which is used to adjust the steps and parameters of the core method for special situations such as low-voltage and multi-power shared lines to ensure that the monitoring covers all scenes and avoids "one-size-fits-all"; S4: The monitoring result analysis and optimization closed loop module is the final landing link of the monitoring, which receives the results of the core monitoring method, proposes optimization measures through trend analysis and abnormal positioning, and feeds back the optimized parameters such as conductor cross-sectional area adjustment and power factor after the installation of reactive power compensation devices to the pre-preparation module to update the monitoring benchmark and form a closed loop of "monitoring-analysis-optimization-re-monitoring".

2. The method of claim 1, wherein: The pre-preparation module further comprises the following steps: defining the monitoring range and boundary, collecting and verifying the basic parameters, and selecting and calibrating the monitoring equipment. The core reference point of the distributed power grid-connected point is determined as the core benchmark point, which is the connection node of the power supply and the power grid and the starting point or key dividing point of the monitoring range. The starting and ending nodes are extended to the "upper grid connection point" on the upper grid side and to the "load access point" on the lower load side, the complete line section from the starting point to the ending point is defined, and the line type is distinguished to determine whether it is a "dedicated line" or a "shared line". Key information is recorded, and the voltage level, physical length, and starting and ending node numbers of the monitoring line are recorded in writing. The parameter collection list is determined, and data is collected through multiple channels. The original parameters of the line are obtained through design drawings, the meter accuracy, sampling frequency, and other information are obtained through the equipment nameplate, the dynamic parameters such as line operating temperature and actual power factor are obtained through on-site measurement, and the parameter accuracy is verified twice. The parameter documents are sorted out. The equipment is selected according to the scene, and the compatibility of the equipment is confirmed. The equipment is calibrated in advance to ensure that the equipment can collect and upload data stably at the set period without packet loss or transmission errors.

3. The method of claim 1, wherein: The core monitoring method module further comprises different methods for monitoring execution, including the metering measurement method and the model estimation monitoring method for different scenes.

4. The method of claim 3, wherein: The metering measurement method is deployed by scientifically arranging monitoring points in the physical layer, and in the deployment process, the number of monitoring points is determined and the monitoring content of each monitoring point is determined, and through standardized equipment installation, data deviation caused by wiring errors is avoided, and the terminal and meter wiring is firm, waterproof, anti-interference protection is done, so that through periodic data collection and preprocessing, the data layer is processed to determine the collection period, collect raw data and data preprocessing.

5. The method of claim 4, wherein: After the metering measurement method scientifically arranges monitoring points and collects and preprocesses data by period, the line loss is calculated in steps to perform the calculation layer, and the single-period input or output total power is calculated, and the single-period power loss, cycle total line loss, line loss rate and segmented line loss calculation (long line) are calculated, and after the calculation is completed, the monitoring results are checked and corrected, and the results are optimized, so that the error source is analyzed and the total error power is calculated, and then the line loss result is corrected and the result rationality is checked.

6. The method of claim 3, wherein: The model estimation monitoring method can be applied to the metering point sparse scene, the line parameter model is built to prepare the modeling layer, the core modeling parameters are focused on the line resistance and reactance, the conductance is ignored, and the line resistance at the standard temperature is calculated: according to the line material, length, cross-sectional area, the formula R O =ρL / S is used for calculation, and the resistance at the actual running temperature is corrected, the line reactance is simplified, and after the line parameter model is built, the key operation data is collected, the collection content is determined, and the end or segmented metering table is not needed, only the total power (active P in , reactive Q in ) and line running temperature (T) at the head end are collected, the data collection cost is reduced, and then the collection period is set. Because there is a certain error in the model estimation, the collection period needs to be slightly shorter than the metering measurement method, so as to ensure that the data can reflect the power fluctuation and reduce the estimation deviation, so as to record and arrange the data, and record the data in the format of "collection time-P in -Q in -T", so as to ensure that the reactive power, temperature data and active power are collected synchronously.

7. The method of claim 6, wherein: After the model estimation monitoring method builds the line parameter model and simplifies the collection of key operation data, the line loss is estimated in steps, the stable calculation of the first apparent power is performed, and the line phase current is derived, and after the completion, the single-period power loss is calculated, the cumulative cycle total line loss is calculated, and the estimated line loss rate is calculated, and after the calculation, the model estimation error is corrected, the calibration benchmark is selected, if there are a small number of metering points, the measured line loss of the metering point is used as the calibration benchmark, and if there are no metering points, the historical measured line loss of the same type line is used as the benchmark, so as to calculate the correction coefficient and correct the estimation result.

8. The method of claim 1, wherein: The special scene adaptation monitoring module can monitor different scenes through low-voltage distributed power supply and multi-power sharing line monitoring. During the low-voltage distributed power supply monitoring process, the monitoring range and monitoring points are adjusted to define the monitoring range, simplify the monitoring point arrangement, adjust the parameters and collection methods, adjust the line parameter calculation and adjust the collection cycle, adjust the line loss calculation logic, and use the formula ΔP=I 2 R for single-phase line calculation, and use the formula ΔW=ΔP×t (t is the running time, such as 24 hours) for periodic line loss calculation, and the line loss rate η=(ΔW / total inverter output power)×100%.

9. The method of claim 8, wherein: The multi-power shared line monitoring optimizes the arrangement of monitoring points, increases the grid-connected point monitoring point and retains the segmented monitoring point, and collects multi-power collaborative data for synchronous data collection and recording of power operation state, and performs superposition loss calculation for calculating single-power single line loss, and calculates superimposed interaction loss and total loss summary.

10. The method of claim 1, wherein: The monitoring result analysis and optimization closed loop module analyzes the monitoring results in depth, performs trend analysis and abnormal positioning, and forms a closed loop by landing optimization measures and forming a closed loop, formulates targeted optimization measures and tracks optimization effect, so that after the optimization measures are implemented, the original monitoring method is continued to be monitored for 1-3 months, the line loss rate before and after optimization is compared, the effectiveness of the measures is verified, and the monitoring benchmark is updated, the optimized line parameters are fed back to the "preparation module", the basic parameter summary table is updated, and the new benchmark is used for subsequent monitoring, forming a closed loop of "monitoring-analysis-optimization-remonitoring".

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