WO2023165348A1

WO2023165348A1 - Method and device for determining switching state of reactive compensation of distribution transformer

Info

Publication number: WO2023165348A1
Application number: PCT/CN2023/076831
Authority: WO
Inventors: 李志华; 谢明磊; 曹德发; 廖明; 李延宾; 李灵勇; 罗海波; 罗威; 魏存良; 曾晓丹; 潘旭扬
Original assignee: 广东电网有限责任公司梅州供电局
Priority date: 2022-03-03
Filing date: 2023-02-17
Publication date: 2023-09-07
Also published as: CN114268110A; CN114268110B

Abstract

Disclosed in the present application are a method and device for determining the switching state of reactive compensation of a distribution transformer. The method comprises: obtaining single-day 96-point measurement data of the distribution transformer, of a low-voltage user meter connected to the distribution transformer, and of a feeder line to which the distribution transformer belongs, and parameter data of a power distribution network to which the distribution transformer belongs; constructing a topological model according to the measurement data and the parameter data; preprocessing the reactive power of a distribution transformer to be determined; and on the basis of the preprocessed reactive power of said distribution transformer, in combination with the topological model, simulating said distribution transformer, and determining the switching state of the reactive compensation of said distribution transformer according to a simulation result.

Description

Discrimination method and device for reactive power compensation switching status of distribution transformer

This application claims the priority of the Chinese patent application with application number 202210200425.1 submitted to the China Patent Office on March 3, 2022, the entire content of which is incorporated herein by reference.

technical field

The present application relates to the field of distribution network technology, for example, to a method and device for discriminating the status of switching on and off of reactive power compensation of distribution transformers.

Background technique

The distribution line itself has the characteristics of complex topology, frequent equipment changes, and variable operation modes. Under the background of large-scale access to new energy sources such as distributed photovoltaics and wind power, the distribution of reactive power flow in the distribution network tends to change. , which puts forward higher requirements for power flow analysis and load forecasting of distribution network. The distribution network analysis and prediction method in the related technology relies on the network production management system, geographic information system (Geographic Information System, GIS) and line equipment parameters and operation data in the metering automation system to carry out topology model construction and simulation analysis, in which the distribution transformer Reactive power compensation switching state is an essential part.

In related technologies, the judgment of reactive power compensation switching status of distribution transformers is mainly based on the multi-day historical changes of transformer power factors. However, due to constraints such as load nature, load rate, and integrity of historical measurement data, the analysis results are accurate. The performance is difficult to guarantee, and the efficiency is low.

Contents of the invention

This application provides a method and device for discriminating reactive power compensation status of distribution transformers, so as to realize the analysis of single-day multi-point measurement data of distribution transformers to be judged in the case of incomplete multi-day measurement data. Determining the switching status of reactive power compensation is conducive to improving the efficiency of distribution network power flow analysis.

This application provides a method for discriminating the reactive power compensation switching status of distribution transformers, including:

Acquire the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the 96-point measurement data of the feeder to which the distribution transformer belongs, and the parameter data of the distribution network to which the distribution transformer belongs; wherein , the measurement data includes at least the reactive power of the distribution transformer to be judged;

Constructing a simulation model according to the measurement data and the parameter data;

Preprocessing the reactive power of the distribution transformer to be judged;

Based on the preprocessed reactive power of the distribution transformer to be judged, combined with the simulation model, the distribution transformer to be judged is simulated, and the reactive power of the distribution transformer to be judged is determined according to the simulation result Compensation status.

Optionally, the measurement data includes current, voltage, active power, reactive power, and power factor of the feeder, the distribution transformer, and the low-voltage household meter; the parameter data includes the distribution network topology data and line parameter data.

Optionally, the simulation model includes a topology model of the feeder and an area low-voltage topology model of the distribution transformer to be judged.

Optionally, the step of preprocessing the reactive power of the distribution transformer to be judged includes:

The positive and negative values of the reactive power of the distribution transformer to be judged are determined, and the reactive power of the distribution transformer to be judged is sorted into a positive power set and a negative power set.

Optionally, the reactive power of the distribution transformer to be judged based on the preprocessing is combined with the simulation model to simulate the distribution transformer to be judged, and determine the reactive power of the distribution transformer to be judged according to the simulation result. The steps of switching on and off state of reactive power compensation of distribution transformer include:

If the reactive power of the distribution transformer to be judged does not have a negative value, perform power flow calculation and simulation on the distribution transformer to be judged based on the low-voltage topology model of the station area, so as to obtain the distribution transformer to be judged The simulation results of reactive power loss on the low-voltage line of the transformer;

Acquiring the actual measured total value of the reactive power of the low-voltage household meter connected to the distribution transformer to be judged;

If (Q _loss + Q _actual - Q _first ) * 100%/Q _first ≥ 3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state;

If (Q _loss +Q _real -Q _first )*100%/Q _first <3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in an exit state;

Wherein, Q _loss is the reactive power loss on the low-voltage line of the distribution transformer to be judged, and Q is _actually the reactive power actual measurement summation value of the low-voltage household meter connected with the distribution transformer to be judged, and Q _{is first} is the total reactive power at the head end of the distribution transformer to be judged.

Optionally, if the reactive power of the distribution transformer to be judged does not have a negative value, perform power flow calculation and simulation on the distribution transformer to be judged based on the low-voltage topology model of the station area, so as to obtain the The steps for describing the simulation results of reactive power loss on the low-voltage line of the distribution transformer to be judged include:

Respectively obtain the reactive power and active power of the distribution transformer to be judged and the low-voltage household meter during the single-day load peak, average and valley periods;

According to the reactive power and active power of the distribution transformer to be judged and the low-voltage household meter in the peak, average and valley load periods of a single day, the low-voltage topology model of the station area is used to analyze the distribution transformer to be judged. Power flow calculation and simulation of the power transformer to obtain the power flow on the low-voltage line of the distribution transformer to be judged Simulation results of reactive power loss.

If the reactive power of the distribution transformer to be judged has a negative value, the power flow calculation simulation is performed on the distribution transformer based on the topology model of the feeder to obtain the simulated voltage of the low-voltage side of each distribution transformer;

Acquire the simulated voltage of the low-voltage side of the distribution transformer that is in the same reactive power flow direction as the distribution transformer to be judged and adjacent to the distribution transformer to be judged, and obtain the simulated voltage at the same time as the distribution transformer to be judged The actual measured value of the low-voltage side voltage of the distribution transformer adjacent to the distribution transformer;

If (U _f -U _s )*100%/U _s ≥ 3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the exit state;

If (U _f -U _s )*100%/U _s <3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state;

Wherein, U _f is the simulation voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged, U _s is the voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged The actual measured value.

Optionally, if the reactive power of the distribution transformer to be judged has a negative value, the power flow calculation and simulation of the distribution transformer is performed based on the topology model of the feeder, so as to obtain the The steps for simulating the voltage on the low voltage side include:

Obtain the time node corresponding to the reactive power of the distribution transformer to be judged as a negative value, and obtain the bus voltage of the feeder line at the time node and the active power and reactive power of the distribution transformer;

Combined with the bus voltage of the feeder and the active power and reactive power of the distribution transformer, the topology model of the feeder is used to perform power flow calculation and simulation on the distribution transformer to obtain the low-voltage side of each distribution transformer simulated voltage.

Optionally, when all distribution transformers adjacent to the distribution transformer to be judged satisfy (U _f −U _s )*100%/U _s <3%, the distribution transformer to be judged is determined The reactive power compensation is in the input state.

The present application also provides a discriminating device for reactive power compensation switching status of distribution transformers, the device comprising:

The data acquisition module is configured to acquire the single-day 96-point measurement data of the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the feeder to which the distribution transformer belongs, and the distribution transformer The parameter data of the distribution network to which the transformer belongs; wherein, the measurement data includes at least the reactive power of the distribution transformer to be judged;

A model building module, configured to build a simulation model according to the measured data and the parameter data;

A preprocessing module, configured to preprocess the reactive power of the distribution transformer to be judged;

The state determining module is configured to simulate the distribution transformer to be judged based on the preprocessed reactive power of the distribution transformer to be judged, and determine the power to be judged according to the simulation result. The switching status of the reactive power compensation of the distribution transformer.

Description of drawings

Fig. 1 is the flow chart of the discriminating method of a kind of distributing transformer reactive power compensation cast-off state provided by the present application;

Fig. 2 is the flow chart of another kind of discriminating method of reactive power compensation switching state of distribution transformer provided by the present application;

Fig. 3 is a flow chart of another method for discriminating reactive power compensation throwing and withdrawing states of distribution transformers provided by the present application;

Figure 4 is a schematic diagram of a 10kV line topology provided by the present application;

Fig. 5 is the flow chart of another kind of discriminating method of distribution transformer reactive power compensation cast-off state provided by the present application;

Fig. 6 is a schematic structural diagram of a discriminating device for reactive power compensation of a distribution transformer provided in the present application.

Detailed ways

The application will be described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only some structures related to the present application are shown in the drawings but not all structures.

In this application, the reactive power compensation device of the distribution transformer refers to the shunt capacitor and other devices installed at the distribution panel (cabinet) of the 400V low-voltage side of the transformer to adjust the reactive voltage and improve the power factor. The reactive power compensation devices of distribution transformers on the actual site have different configuration capacities, different product models, and large differences in intelligence levels. Among them, manual switching has problems such as unrecorded switching, chaotic ledgers, and improper management; intelligent switching There are problems such as differences in switching rules and local data not being uploaded, which makes it difficult to judge the switching status of reactive power compensation of distribution transformers. Aiming at the above problems, this application proposes a method for discriminating the status of reactive power compensation of distribution transformers, so as to reduce the status of reactive power compensation of distribution transformers. difficulty of discrimination. The method provided by this application can realize the judgment of the reactive power compensation switching status of distribution transformers in multiple time and space dimensions under incomplete measurement conditions, wherein the "incomplete measurement conditions" refers to: the distribution transformer to be judged without The switching status of power compensation is unknown, and the historical measurement data of more than 2 days of the distribution transformer to be judged belongs to the feeder and the low-voltage household meter connected to it is incomplete; The feeder line to which the electric transformer belongs and the low-voltage household meter connected to it are known at 96 points per day (15 minutes/point), the station-line-transformer-household topological relationship is complete, and the inherent parameters of the power line are accurate.

Fig. 1 is a flow chart of a method for discriminating reactive power compensation switching status of distribution transformer provided by the present application. With reference to Fig. 1, the discriminating method of reactive power compensation switching status of distribution transformer provided by the present application includes:

S110. Obtain the daily 96-point measurement data of the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the feeder to which the distribution transformer belongs, and the parameter data of the distribution network to which the distribution transformer belongs.

A distribution network usually consists of distribution substations, feeders, distribution transformers and users, including low-voltage household meters connected to distribution transformers at the user end. The single-day 96-point measurement data of the distribution transformer can be the electrical parameters of the distribution transformer during operation, and the single-day 96-point measurement data of the low-voltage household meter connected to the distribution transformer can be the low-voltage household meter connected to the distribution transformer. For the electrical parameters during operation, the 96-point measurement data of the feeder to which the distribution transformer belongs in a single day can be the electrical parameters of the feeder to which the distribution transformer belongs during operation. The 96-point measurement data in a single day refers to the real-time electrical parameter data measured at 96 points (one point every 15 minutes) within 24 hours. The parameter data of the distribution network to which the distribution transformer belongs may be physical parameter data of the distribution network. In this embodiment, since the reactive power compensation status of the distribution transformer needs to be identified, the measurement data at 96 points in a single day must at least include the reactive power of the distribution transformer.

It should be noted that there are multiple distribution transformers in the distribution network. When obtaining the 96-point measurement data of related equipment in a single day, each set of distribution transformers and the low-voltage household meters connected to each set of distribution transformers All electrical parameters need to be obtained in order to prepare for the subsequent determination of the reactive power compensation switching status of the distribution transformer to be judged.

S120. Construct a simulation model according to the measurement data and parameter data.

After obtaining the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the daily 96-point measurement data of the feeder to which the distribution transformer belongs, and the parameter data of the distribution network to which the distribution transformer belongs, according to The obtained relevant data constructs the medium and low voltage simulation topology model, so as to simulate the subsequent relevant steps.

S130. Preprocessing the reactive power of the distribution transformer to be determined.

Preprocessing refers to sorting and classifying the reactive power of all distribution transformers in the current distribution network. Exemplarily, for example, the reactive power of all distribution transformers is classified according to the conditions of positive and negative values, so as to filter out the cases where the reactive power is negative.

S140. Based on the pre-processed reactive power of the distribution transformer to be judged, combined with the simulation model, The distribution transformer to be judged is simulated, and the reactive power compensation switching state of the distribution transformer to be judged is determined according to the simulation result.

According to the preprocessing results of the reactive power of the distribution transformer to be judged, an appropriate topology model is selected for simulation, and the reactive power compensation status of the distribution transformer to be judged is determined according to the obtained simulation results. For example, based on the spillover effect of low-voltage reactive power compensation of distribution transformers and the principle of lifting the low-voltage side voltage of adjacent distribution transformers, the simulation of the low-voltage side voltage of adjacent distribution transformers with the distribution transformer to be judged The size relationship between the value and the actual measurement value is used to determine the switching status of the reactive power compensation of the distribution transformer to be judged. If the simulated value and the actual measured value satisfy the preset relationship, it can be determined that the reactive power compensation of the distribution transformer to be judged is in an exit state. According to the principle of low-voltage reactive power compensation of distribution transformers, the relationship between the reactive power at the first and last ends of the distribution transformer to be judged can be compared to determine the switching status of the reactive power compensation of the distribution transformer to be judged. If the reactive power at the end of the distribution transformer to be judged (that is, the user end) is greater than the reactive power at the head end of the distribution transformer to be judged, it indicates that the reactive power compensation of the distribution transformer to be judged has been put into operation. If the reactive power at the end of the distribution transformer to be judged (that is, the user end) is less than or equal to the reactive power at the head end of the distribution transformer to be judged, it means that the reactive power compensation of the distribution transformer to be judged is exit status.

The technical solution provided by this application is based on the acquired distribution transformer, the low-voltage household meter connected to the distribution transformer, and the 96-point measurement data of the feeder line to which the distribution transformer belongs, and the distribution network to which the distribution transformer belongs. Based on the parameter data of the distribution transformer to be judged, the simulation model is constructed, and based on the preprocessed reactive power of the distribution transformer to be judged, combined with the simulation model, the distribution transformer to be judged is simulated, and the distribution transformer to be judged is determined according to the simulation results. The switching status of reactive power compensation. Compared with the method of judging the switching status of low-voltage reactive power compensation based on the multi-day historical changes of the power factor of the distribution transformer in the related art, the technical solution provided by this application only needs to obtain the distribution transformer and connect it to the distribution transformer. The low-voltage household meter and the measurement data of 96 points (15 minutes/point) in a single day of the feeder to which the distribution transformer belongs are used to judge whether the reactive power compensation device is put into operation, without obtaining the multi-day history of the power factor of the distribution transformer It realizes the accurate judgment of reactive power compensation of distribution transformers under incomplete measurement conditions, avoids analysis obstacles caused by incomplete measurement data collection, and helps to improve the efficiency of distribution network reactive power flow simulation . Since the method is not constrained by conditions such as load nature, load rate, and integrity of historical metering data, it can improve the accuracy of reactive power compensation status identification.

Optionally, in this embodiment, the measurement data includes the current, voltage, active power, reactive power and power factor of feeders, distribution transformers and low-voltage household meters. Optionally, the measurement data can be passed through the metering automation system Sample acquisition. The parameter data includes the topology data of the distribution network, the parameter data of the feeder, the model and wiring group of the distribution transformer, among which the topology data can be the topology data of the substation-feeder-distribution transformer-low-voltage household meter, and the topology data can be Acquired through GIS. The parameter data of the line includes data such as line path, length, line type, transformer model, and wiring group. You can find the parameter data of the line through the user data manual.

Optionally, in step S120, the simulation model includes the topology model of the feeder and the low-voltage topology model of the distribution transformer to be judged, and the ETAP simulation software can be used for model building.

Optionally, Fig. 2 is a flow chart of another method for discriminating reactive power compensation status of distribution transformers provided by the present application. Referring to Fig. 2, the method for discriminating reactive power compensation statuses of distribution transformers provided by the present application include:

S1201. Construct the topology model of the feeder and the low-voltage topology model of the distribution transformer to be determined according to the measurement data and parameter data.

S1301. Determine the positive and negative values of the reactive power of the distribution transformer to be judged, and organize the reactive power of the distribution transformer to be judged into a positive power set and a negative power set.

The preprocessing process includes sorting out the reactive power data of the distribution transformer to be judged at 96 points (15 minutes/point) in a single day, and determining the positive and negative values of the reactive power at 96 points, and dividing the distribution transformer to be judged according to the positive and negative values. The reactive power of 96 points in a single day of an electric transformer is divided into a positive power set and a negative power set.

S1401. If the reactive power of the distribution transformer to be judged does not have a negative value, perform power flow calculation and simulation on the distribution transformer to be judged based on the low-voltage topology model of the station area, so as to obtain the reactive power on the low-voltage line of the distribution transformer to be judged. Power loss simulation results.

S1402. Obtain the actual measured total value of the reactive power of the low-voltage household meter connected to the distribution transformer to be judged.

S1403. If (Q _loss +Q _real -Q _first )*100%/Q _first≥3 %, determine that the reactive power compensation of the distribution transformer to be judged is in the input state.

S1404. If (Q _loss +Q _real -Q _first )*100%/Q _first <3%, determine that the reactive power compensation of the distribution transformer to be judged is in an exit state.

Among them, Q _loss is the reactive power loss on the low-voltage line of the distribution transformer to be judged, Q is _actually the actual measured total value of reactive power of the household meter connected to the distribution transformer to be judged, _{and the beginning} of Q is the distribution transformer to be judged The total reactive power at the head end of the transformer. If there is no negative value in the 96-point reactive power data of the distribution transformer to be judged, that is, the 96-point reactive power data of the distribution transformer to be judged are all positive power sets, then the low-voltage topology model of the station area is used to treat the judged The power flow calculation and simulation of the distribution transformer is carried out to obtain the simulation result Q _{loss of} reactive power loss on the low-voltage line of the distribution transformer to be judged, that is, to obtain the reactive power loss of the low-voltage side of the transformer to be judged (it should be understood that this The reactive power loss at is the total reactive power loss of the low-voltage side of the transformer to be judged). And at the same moment corresponding to obtaining the reactive loss simulation value Q _loss , obtain the total reactive power Q _first of the head end of the distribution transformer to be judged, and the connection with the distribution transformer to be judged _The actual measured total value Q of reactive power of all the low-voltage household meters. According to the nearby compensation principle of low-voltage reactive power compensation of distribution transformers, through the simulation value Q _{loss of} reactive power loss of the distribution transformer to be judged and the actual reactive power of all low-voltage household meters connected to the distribution transformer to be judged The sum _of the measured total value Q is compared with the total reactive power Q _{at the} head end of the distribution transformer to be judged to determine the switching status of the reactive power compensation of the distribution transformer to be judged. If (Q _loss + Q _actual - Q _first )*100%/Q _first ≥ 3%, that is, the reactive power loss of the low-voltage side of the distribution transformer to be judged and the low-voltage household meter connected to the distribution transformer to be judged If the sum of the actual measured reactive power values is higher than or equal to 3% of the total reactive power at the head end of the distribution transformer to be judged, then it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state. Conversely, if (Q _loss + Q _real - Q _first ) * 100% / Q _first < 3%, that is, the reactive power loss of the low-voltage side of the distribution transformer to be judged is not the same as the low-voltage household connected to the distribution transformer to be judged. If the sum of the actual measured reactive power values of the table is lower than 3% of the total reactive power at the head end of the distribution transformer to be judged, then it is determined that the reactive power compensation of the distribution transformer to be judged is in the exit state.

Exemplarily, in the specific implementation process, the specific process of step S1401 to obtain the reactive power loss simulation results on the low-voltage line of the distribution transformer to be judged may be: respectively obtain the distribution transformer to be judged and the low-voltage household meter in a single day Reactive power and active power during peak load, average value and valley value period; according to the reactive power and active power of distribution transformer and low-voltage household meter to be judged in single day load peak value, average value and valley value period, the The district low-voltage topology model performs power flow calculation and simulation on the distribution transformer to be judged, so as to obtain the simulation results of reactive power loss on the low-voltage line of the distribution transformer to be judged.

Under the condition that the reactive power of 96 points of the distribution transformer to be judged does not have a negative value, all positive and reactive power sets are simulated. There are four periods of peak, peak, flat, and valley inside the low-voltage household meter. Among them, the peak and peak periods are the time of high power consumption. There are many power users and large power consumption. The grid may have insufficient power supply. The system frequency Decrease; flat, when the power consumption is normally and reasonably used, the grid power supply is sufficient, and the frequency is stable; valley, that is, during the low valley period at night, the grid will have excess power and the frequency will rise, which will also cause imbalance and cause the power supply system to lose its economy. In this embodiment, a total of three time sections of single-day load peak value, average value, and valley value are selected, and the distribution transformer to be judged on the three time sections and the household meter in the station area connected to the distribution transformer to be judged are selected. Substituting the active power and reactive power of the distribution transformer to be judged into the low-voltage topology model of the distribution transformer to be judged for power flow calculation and simulation, the simulation results of reactive power loss on the low-voltage line of the distribution transformer to be judged are obtained.

In this step, under the condition that the reactive power of 96 points of the distribution transformer to be judged is all positive, by using the low-voltage topological model of the distribution transformer to be judged, a total of 3 daily load peaks, flats, and valleys are carried out. The reactive power loss simulation of the station area on a time section. Optionally, the improved Newton-Raphson method can be used for power flow calculation.

Optionally, Fig. 3 is a flowchart of another method for discriminating reactive power compensation status of distribution transformers provided by the present application. Referring to Fig. 3, the method for discriminating reactive power compensation statuses of distribution transformers Laws include:

S1411. If the reactive power of the distribution transformer to be judged has a negative value, perform power flow calculation and simulation on the distribution transformer based on the topology model of the feeder, so as to obtain the simulated voltage of the low-voltage side of each distribution transformer.

S1412. Acquire the simulation voltage of the low-voltage side of the distribution transformer that is in the same reactive power flow direction as the distribution transformer to be judged and adjacent to the distribution transformer to be judged, and obtain the simulation voltage of the distribution transformer to be judged at the same time The actual measured value of the low voltage side voltage of the adjacent distribution transformer.

S1413. If (U _f −U _s )*100%/U _s ≥3%, determine that the reactive power compensation of the distribution transformer to be judged is in an exit state.

S1414. If (U _f −U _s )*100%/U _s <3%, determine that the reactive power compensation of the distribution transformer to be judged is in the input state.

Among them, U _f is the simulated voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged, and _Us is the actual measured value of the voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged. If there are negative values in the 96-point reactive power data of the distribution transformer to be judged, then the 96-point reactive power data of the distribution transformer to be judged are classified into positive power sets and negative power sets, and for the distribution transformer to be judged The negative reactive power set of the transformer is simulated using the topology model of the feeder to obtain the simulated voltage of the low-voltage side of each distribution transformer, and obtain the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged at the same time The actual measured value of the side voltage. According to the spillover effect of the reactive power compensation of the distribution transformer and the lifting principle of the low-voltage side voltage of the adjacent distribution transformer, by comparing the simulation of the low-voltage side voltage of other distribution transformers adjacent to the distribution transformer to be judged The size between the measured value and the actual measured value is used to determine whether the reactive power compensation of the distribution transformer to be judged is put into use.

For example, the simulation voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged is U _f , which is in the same reactive power flow direction as the distribution transformer to be judged, and the low-voltage side of the adjacent distribution transformer The actual measured value U _s of the side voltage. If (U _f -U _s )*100%/U _s ≥ 3%, that is to say, the simulated voltage value of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged is higher than the actual measured value, then determine The reactive power compensation of the distribution transformer to be judged is in the exit state. If (U _f -U _s )*100%/U _s <3%, that is to say, the voltage simulation value of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged is lower than the actual If the measured value shows that the voltage on the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged is increased, it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state.

In this embodiment, when there are multiple distribution transformers adjacent to the distribution transformer to be judged, the voltage on the low-voltage side of all distribution transformers satisfies (U _f -U _s )*100%/U _s <3%, it can be determined that the reactive power compensation of the distribution transformer to be judged is in the input state.

Exemplarily, in the specific implementation process, the specific process of obtaining the simulation voltage of the low-voltage side of each distribution transformer in step S1411 may be: obtaining the time node corresponding to the negative value of the reactive power of the distribution transformer to be judged, And obtain the busbar voltage of the feeder line and the active power and reactive power of the distribution transformer at this time node; combined with the busbar voltage of the feeder line and the active power and reactive power of the distribution transformer, the topology model of the feeder line is used to carry out the power flow analysis of the distribution transformer Simulations are calculated to obtain simulated voltages on the low voltage side of each distribution transformer.

In the case that the reactive power of 96 points of the distribution transformer to be judged has a negative value, select the time section where the negative reactive power is located, and the corresponding negative reactive power of the distribution transformer to be judged on the time section The bus voltage of the feeder at the time node and the active power and reactive power of all distribution transformers (including the distribution transformer to be judged) on the feeder are substituted into the topology model of the feeder for power flow calculation and simulation, and each distribution transformer is obtained Simulated voltage on the low voltage side of an electrical transformer. This step is to perform power flow calculation simulation at the time node when the reactive power of the distribution transformer to be judged is negative through the topology model of the feeder. Optionally, the improved Newton-Raphson method is used for power flow calculation.

Optionally, FIG. 4 is a schematic diagram of a 10kV line topology provided by the present application, and FIG. 5 is a flow chart of another method for discriminating reactive power compensation switching status of distribution transformers provided by the present application. Combining FIG. 4 and FIG. 5. Explain the specific working principle of the method for discriminating the reactive power compensation status of distribution transformers provided by this application.

Figure 4 provides a 10kV distribution line L, including 5 distribution transformers (respectively labeled T1, T2, T3, T4, T5, the feeders of the 5 distribution transformers are all line L), and the distribution transformer to be judged It is T3, and there are 5 low-voltage household meters (respectively labeled h1, h2, h3, h4, h5) connected under T3, and R1, R2, R3, R4 are line impedances.

Exemplarily, obtain 96 points (15 minutes/point) of 10kV distribution line L, distribution transformers (T1, T2, T3, T4, T5), and low-voltage household meters (h1, h2, h3, h4, h5) in a single day ) measurement data and parameter data of the distribution network to which the distribution transformer belongs (including station-line-transformer-household topology data and line parameter data). The measurement data at 96 points (15 minutes/point) in a single day includes current, voltage, active power, reactive power, and power factor, etc. The station-line-substation-household topology data can be obtained through GIS; the line parameter data package It includes parameters such as line path, length, line type, transformer model, and wiring group.

Based on the data obtained in step S110, build the medium-voltage topology model of the 10kV distribution line L and the low-voltage topology model of the distribution transformer T3 to be judged.

Exemplarily, the reactive power data of the distribution transformer to be judged at 96 points (15 minutes/point) in a single day is sorted out, and the positive and negative values of the reactive power at 96 points are determined, and the distribution transformer to be judged is divided according to the positive and negative values. The reactive power of 96 points in a single day of an electric transformer is divided into a positive power set and a negative power set.

S151. Judging whether (Q _loss +Q _real -Q _first )*100%/Q _first is greater than or equal to 3%.

Exemplarily, a simulation analysis is performed on the positive power set of the distribution transformer T3 to be judged. Select a total of three time sections of daily load peak, average, and valley values, and use the distribution transformer T3 to be judged on the three time sections and the household meters (h1, h2, h3, h4, h5) connected to T3 Substituting the active power and reactive power of the distribution transformer T3 to be judged into the low-voltage topological model of the distribution transformer T3 for power flow calculation and simulation, the simulation results of reactive power loss on the low-voltage line of the distribution transformer T3 to be judged are obtained.

In this embodiment, it is assumed that the total reactive power at the head end of the distribution transformer T3 to be judged at the selected single-day load peak time is Q _first , the simulation result of reactive power loss in the station area is Q _loss , and the low-voltage household meter in the station area ( h1, h2, h3, h4, h5) The measured values of actual reactive power are Q1, Q2, Q3, Q4, Q5.

Calculate the actual measured total value Q of the reactive power of the low-voltage household meters (h1, h2, h3, h4, h5) in the station area corresponding to the three time sections of the distribution transformer T3 single-day load peak, flat, and valley values to be _judged ( _Qactual =Q1+Q2+Q3+Q4+Q5), and add it to the reactive power loss simulation result Q _loss in the station area to get the total value, which is then combined with the head-end total value of the distribution transformer T3 to be judged The reactive power Q is _first compared to determine whether the summed value is higher than the total reactive power by more than 3%. If (Q _loss + Q _real - Q _first ) * 100% / Q _first ≥ 3%, it is determined that the reactive power compensation of the distribution transformer T3 to be judged is in the input state, if (Q _loss + Q _real - Q _first ) * 100%/Q _first <3%, it is determined that the reactive power compensation of the distribution transformer T3 to be judged is in the exit state.

S1411. If the reactive power of the distribution transformer to be judged has a negative value, based on the topology model of the feeder, The power flow calculation simulation of distribution transformers is carried out in order to obtain the simulated voltage of the low-voltage side of each distribution transformer.

S152. Determine whether (U _f −U _s )*100%/U _s is greater than or equal to 3%.

Exemplarily, a simulation analysis is performed on the negative power set of the distribution transformer T3 to be judged. Select the time section where each negative value is located in the negative power set, and calculate the bus voltage U ₀ of the 10kV distribution line L and the distribution transformers (T1, T2, T3, T4, T5) on the time section where each negative value is located. The active power and reactive power are substituted into the topology model of the 10kV distribution line L for power flow calculation and simulation, and the simulation results of the low-voltage side voltage of each distribution transformer are obtained. Assuming that there is only one value in the negative power set, the simulation results of the low-voltage side voltages of multiple distribution transformers at the time corresponding to the negative value are U _f1 , U _f2 , U _f3 , U _f4 , U _f5 , and the actual voltage The measured values are U _s1 , U _s2 , U _s3 , U _s4 , U _s5 .

Select the simulated values U _f2 and U _f4 of the low-voltage side voltages of the distribution transformer T2 and distribution transformer T4 that are in the same reactive power flow direction as the distribution transformer T3 to be judged and adjacent to each other, and the distribution transformer T2 at this moment. Compare with the actual voltage measurement values Us2 and Us4 of the distribution transformer T4, if (U _f2 - U _s2 )*100%/U _s2 ≥3%, and (U _f4 -U _s4 )*100%/U _s4 ≥ 3%, it is determined that the reactive power compensation of the distribution transformer T3 to be judged is in the exit state. If (U _f2 - U _s2 )*100%/U _s2 <3%, and (U _f4 -U _s4 )*100%/U _s4 <3%, it is determined that the reactive power compensation of the distribution transformer T3 to be judged is put into state.

The technical solution provided by this application is based on the spillover effect of reactive power compensation of distribution transformers and the principle of raising the voltage on the low-voltage side of adjacent distribution transformers, or based on the principle of nearby compensation for reactive power compensation of distribution transformers. The analysis of multi-point (96 points) measurement data of distribution transformers in a single day and topology modeling and simulation can realize the judgment of the low-voltage reactive power compensation switching status of distribution transformers to be judged. Compared with the method of judging the switching status of low-voltage reactive power compensation based on the multi-day historical changes of the power factor of the distribution transformer, the method provided by this embodiment only needs to select the measurement data of 96 points (15 minutes/point) in a single day , which avoids the analysis obstacles caused by the incomplete collection of measurement data, and helps to improve the efficiency of reactive power flow simulation of distribution network.

Fig. 6 is a schematic structural diagram of a discriminating device for distributing transformer reactive power compensation throwing and withdrawing states provided by the present application. With reference to Fig. To obtain the daily 96-point measurement data of the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the feeder to which the distribution transformer belongs, as well as the parameter data of the distribution network to which the distribution transformer belongs; among them, the measurement data shall be at least Including the reactive power of the distribution transformer to be judged; the model building module 12 is configured to construct a simulation model according to the measured data and parameter data; the preprocessing module 13 is configured to preprocess the reactive power of the distribution transformer to be judged ; The state determination module 14 is set to be based on preprocessing Finally, the reactive power of the distribution transformer to be judged is combined with the simulation model to simulate the distribution transformer to be judged, and the reactive power compensation status of the distribution transformer to be judged is determined according to the simulation results.

The discriminating device for distributing transformer reactive power compensation switching status is configured to implement the discriminating method for distributing transformer reactive power compensation switching status provided by any of the above embodiments, and has corresponding functional modules and effects for executing the method, which will not be repeated here.

Claims

A method for discriminating reactive power compensation switching and withdrawing states of distribution transformers, comprising:

Acquire the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the 96-point measurement data of the feeder to which the distribution transformer belongs, and the parameter data of the distribution network to which the distribution transformer belongs; wherein , the measurement data includes at least the reactive power of the distribution transformer to be judged;

Constructing a simulation model according to the measurement data and the parameter data;

Preprocessing the reactive power of the distribution transformer to be judged;

Based on the preprocessed reactive power of the distribution transformer to be judged, combined with the simulation model, the distribution transformer to be judged is simulated, and the reactive power of the distribution transformer to be judged is determined according to the simulation result Compensation status.
The method for judging the reactive power compensation state of a distribution transformer according to claim 1, wherein the simulation model includes a topology model of the feeder and a low-voltage topology model of the distribution transformer to be judged.
The method for judging the reactive power compensation switching state of a distribution transformer according to claim 2, wherein the step of preprocessing the reactive power of the distribution transformer to be judged comprises:

The positive and negative values of the reactive power of the distribution transformer to be judged are determined, and the reactive power of the distribution transformer to be judged is sorted into a positive power set and a negative power set.
According to claim 3, the method for discriminating the reactive power compensation switching state of distribution transformers, wherein, the reactive power of the distribution transformers to be judged based on the preprocessing, combined with the simulation model, is used for the The step of performing simulation on the judged distribution transformer, and determining the reactive power compensation switching state of the distribution transformer to be judged according to the simulation result includes:

In the case that the reactive power of the distribution transformer to be judged does not have a negative value, the power flow calculation and simulation of the distribution transformer to be judged is performed based on the low-voltage topology model of the station area, so as to obtain the reactive power of the distribution transformer to be judged Simulation results of reactive power losses on low-voltage lines of distribution transformers;

Acquiring the actual measured total value of the reactive power of the low-voltage household meter connected to the distribution transformer to be judged;

In the case of (Q loss + Q actual - Q first * 100%/Q first ≥ 3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state;

In the case of (Q loss +Q real -Q first )*100%/Q first <3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in an exit state;

Wherein, Q loss is the reactive power loss on the low-voltage line of the distribution transformer to be judged, and Q is actually the reactive power actual measurement summation value of the low-voltage household meter connected with the distribution transformer to be judged, and Q is first is the total reactive power at the head end of the distribution transformer to be judged.
According to claim 3, the method for discriminating the reactive power compensation switching state of distribution transformers, wherein, the reactive power of the distribution transformers to be judged based on the preprocessing, combined with the simulation model, is used for the The step of performing simulation on the judged distribution transformer, and determining the reactive power compensation switching state of the distribution transformer to be judged according to the simulation result includes:

In the case that the reactive power of the distribution transformer to be judged has a negative value, perform power flow calculation and simulation on the distribution transformer based on the topology model of the feeder to obtain a simulation of the low-voltage side of each distribution transformer Voltage;

Acquire the simulated voltage of the low-voltage side of the distribution transformer that is in the same reactive power flow direction as the distribution transformer to be judged and adjacent to the distribution transformer to be judged, and obtain the simulated voltage at the same time as the distribution transformer to be judged The actual measured value of the low-voltage side voltage of the distribution transformer adjacent to the distribution transformer;

In the case of (U f -U s )*100%/U s ≥3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the exit state;

In the case of (U f -U s )*100%/U s <3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state;

Wherein, U f is the simulation voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged, U s is the voltage of the low-voltage side of the distribution transformer adjacent to the distribution transformer to be judged The actual measured value.
The method for judging the state of reactive power compensation of distribution transformers according to claim 5, wherein all distribution transformers adjacent to the distribution transformer to be judged satisfy (U f -U s )*100 In the case of %/U s <3%, it is determined that the reactive power compensation of the distribution transformer to be judged is in the input state.
The method for judging the state of reactive power compensation of distribution transformers according to claim 5, wherein, when the reactive power of the distribution transformer to be judged has a negative value, based on the topology of the feeder The model performs power flow calculation and simulation on the distribution transformer to obtain the simulated voltage of the low-voltage side of each distribution transformer, including:

Obtain the time node corresponding to the reactive power of the distribution transformer to be judged as a negative value, and obtain the bus voltage of the feeder line at the time node and the active power and reactive power of the distribution transformer;

Combined with the bus voltage of the feeder and the active power and reactive power of the distribution transformer, the topology model of the feeder is used to perform power flow calculation and simulation on the distribution transformer to obtain the low-voltage side of each distribution transformer simulated voltage.
The method for judging the reactive power compensation switching status of distribution transformers according to claim 1, wherein the measured data includes the current, voltage, and active power of the feeder, the distribution transformer, and the low-voltage household meter , reactive power and power factor; the parameter data includes topology data and line parameter data of the distribution network.
A discriminating device for distributing transformer reactive power compensation switching status, comprising:

The data acquisition module is configured to acquire the single-day 96-point measurement data of the distribution transformer, the low-voltage household meter connected to the distribution transformer, and the feeder to which the distribution transformer belongs, and the distribution transformer The parameter data of the distribution network to which the transformer belongs; wherein, the measurement data includes at least the reactive power of the distribution transformer to be judged;

A model building module, configured to build a simulation model according to the measured data and the parameter data;

A preprocessing module, configured to preprocess the reactive power of the distribution transformer to be judged;

The state determining module is configured to simulate the distribution transformer to be judged based on the preprocessed reactive power of the distribution transformer to be judged, and determine the power to be judged according to the simulation result. The switching status of the reactive power compensation of the distribution transformer.