CN104036074B - Low voltage discrimination method for distribution substation regions - Google Patents

Abstract

A method for judging low voltage in a distribution station area, which can help power grid operation and management personnel plan the transformation of a distribution station area, and check whether the design of a transformation or new project is reasonable. The present invention is based on the Simulink simulation platform of Matlab, automatically reads information such as the main transformer model, main line branch line connection mode, wire model, wire length, load size, etc. Under the same load conditions, a distribution station area is analyzed and calculated to display the degree of low voltage, the lowest voltage at the end, and the range of low voltage, and automatically proposes the transformation of the station area in terms of changing the line path and changing the wiring mode. best plan. The method of the present invention makes up for the previous deficiency that a model must be established separately for accurate analysis of a single station area, avoids the weakness that a large number of distribution station areas cannot be comprehensively evaluated macroscopically, and can be used for judging whether the voltage of a distribution station area is low, for distribution The design of the reconstruction and new construction of the radio station area brings great convenience.

Description

Discrimination method for low voltage in distribution station area

technical field

The invention relates to a method for judging low voltage in a power distribution station area, and belongs to the field of intelligent power utilization in power system distribution networks.

Background technique

The distribution station area is a network that directly supplies power to users, and its power quality directly affects the daily production and life of users. Due to the sharp increase in power consumption of users, the original construction standards of many distribution stations have fallen behind, and the terminal voltage of a large number of distribution stations has been low, which affects the daily production and life of users.

The power operation and maintenance management department gradually upgrades the transformation of the low-voltage station area. Due to the limited resources of the transformation, the transformation cannot be completed at one time. Transformation sequence. Due to the large number of distribution stations, the specific conditions of each station are different, and the power load of the station at different times is also changing, so it is impossible to have a comprehensive understanding of the distribution network. At present, the main basis for determining whether the voltage in the station area is low is that the user complains to the power supply department, and the relevant personnel go to the site to investigate and measure, so that they can basically understand the situation in the station area at that time. This is time-consuming and laborious, and the effect is limited.

The present invention is based on the Simulink simulation platform of Matlab, automatically reads information such as the main transformer model, main line branch line connection mode, wire model, wire length, load size, etc. Under the same load conditions, a distribution station area is analyzed and calculated to display the degree of low voltage, the lowest voltage at the end, and the range of low voltage, and automatically proposes the transformation of the station area in terms of changing the line path and changing the wiring mode. best plan.

Contents of the invention

The purpose of the present invention is to provide a method for quickly judging the low voltage of a low-voltage distribution station area, which can help power grid operation and management personnel plan the transformation of the distribution station area, and check whether the design of the reconstruction or new project is reasonable.

To achieve this purpose, the present invention adopts the following technical solutions.

A method for quickly judging the low voltage of a low-voltage distribution station, including the following main contents:

(1) Establish the information database of the distribution sub-area to be analyzed. The information is used to judge whether the voltage of the distribution sub-area is low and to put forward suggestions for improvement. The information database includes the electrical parameters of the equipment: the model capacity of the distribution transformer in the distribution station area, the phase number, model and length of each section of wire, the position and size of the main load, etc. It also includes related economic parameters: equipment price, design and construction cost, etc.

(2) Based on the Simulink simulation platform of Matlab, the simulation model of the distribution station area is established. The simulation model is composed of three-phase 10kV AC power supply, three-phase distribution transformer (10kV/400V), three-phase wire, three-phase load and other parts. The power supply is connected to the high-voltage end of the three-phase distribution transformer, and the low-voltage end of the three-phase distribution transformer is connected to the three-phase load through three-phase wires; these models can be directly used in the Powersystem component library of Simulink. Due to the function of Simulink itself, the devices in the model can use the Matlab program to assign values to their parameters. The assignment method is to write the m file and call the "set_param" function to set the capacity of the distribution transformer, the impedance value of the wire, and the active and reactive power value of the load. Wait for the assignment.

(3) Edit the Matlab program to automatically read the information database of the distribution station area, and use the "xlsread" command to read the file. And according to the information, use the method of assignment as in (2) to assign values to the simulation model, including electrical parameters such as distribution transformers, wires, and loads.

(4) The simulation model assigns values to the model through the information library, and the assigned parameters can also be displayed through the graphical user interface (GUI window), and the distribution transformer can be flexibly changed in the corresponding position of the GUI window according to the actual situation , wire, load and other parameters to help technicians design the distribution station area.

(5) The simulation result of the simulation model is that the Simulink program of Matlab automatically simulates the built model according to the circuit principle, and obtains the voltage and current values of each set point of the model. For the simulation analysis of a single distribution station area, the simulation results can be displayed through the GUI window, that is, the voltage value of each point, the output current value of the distribution transformer, etc. If there is a low voltage problem, the optimization program in the m file will be called to automatically calculate and Display the optimal solution; if you want to have a comprehensive macroscopic understanding of a large number of stations, you need to continuously analyze multiple stations, then automatically generate files, use "xlswrite" to output the results, and record the low voltage of each station according to the simulation results Point, terminal voltage value, and comprehensive economic and technical effects to propose the optimal solution for each station area. The calculation method of the optimal solution is to change the parameters of the device by calling the optimization program in the m-file, so that the model changes from a low-cost model to a high-cost model, until the voltage of the whole station is qualified, and the obtained model device parameters are the most Excellent solution.

The beneficial effect of the present invention is that, the present invention adopts the low-voltage simulation method of the distribution station area based on Simulink in Matlab to make up for the insufficiency of having to establish models separately for the accurate analysis of a single station area in the past, and avoids that a large number of distribution station areas cannot be comprehensively The weakness of the macroscopic evaluation can bring great convenience to the judgment of whether the voltage of the distribution station area is low, the reconstruction of the distribution station area and the design of new construction.

Description of drawings

Fig. 1 is a schematic flowchart of a method for judging low voltage in a specific embodiment of the present invention.

detailed description

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments.

Fig. 1 is a schematic flowchart of a method for judging low voltage in a specific embodiment of the present invention.

As shown in FIG. 1 , the method for judging the low voltage in the paired station area of the present invention includes the following steps.

(1) Select the simulation mode, including two modes: mode 1 is to analyze and simulate a single station area, which is mainly used to understand the status quo of a specific station area, or analyze renovation suggestions, or evaluate new plans; mode 2 is to analyze and simulate multiple stations Conduct a macro understanding of the district, compare the effects of different schemes, or analyze the most serious problems in the district, and provide decision-making basis for the arrangement and transformation plan of the power grid operation and maintenance management department.

The simulation model consists of three-phase 10kV AC power supply, three-phase distribution transformer (10kV/400V), three-phase wire, three-phase load and other parts. These models can be directly used in the Powersystem component library of Simulink. Due to the function of Simulink itself, the devices in the model can use the Matlab program to assign values to their parameters. The assignment method is to write the m file and call the "set_param" function to set the capacity of the distribution transformer, the impedance value of the wire, and the active and reactive power value of the load. Wait for the assignment.

(2) If you choose a single analysis, you do not need to input parameters from the database, but directly input parameters from the edited GUI window, and the simulation results and optimal solution suggestions are also directly displayed through the GUI window, which is convenient and flexible. The simulation results displayed in the GUI window are the voltage value of each point, the output current value of the distribution transformer, etc. If there is a low voltage problem, the optimization program in the m file is called. The main principle of the optimization program is to change the parameters of the device to make the model from the cost Change from low to high-cost models until the voltage of the entire station is qualified, and the obtained model device parameters are automatically calculated and displayed as the optimal solution.

(3) If the batch analysis mode is selected, the simulation will be carried out in an automatic batch mode, and the results and the display of the optimal solution suggestion will be output in the form of a file. The output method is to use the "xlswrite" function to record the voltage deviation of each station area according to the simulation results. Low point, terminal voltage value, and comprehensive economic and technical effects to propose the optimal solution for each station area.

The simulation model of the present invention can carry out the simulation under various situations according to needs:

(1) Low voltage conditions under different power factors;

(2) Low voltage conditions under different load access rates;

(3) Low voltage conditions under different load models, etc.

The present invention can also conveniently expand its simulation function, such as introducing harmonic analysis, three-phase unbalance analysis, reactive power compensation analysis and so on.

Claims (5)

1. A method for discriminating low voltage in a distribution station area, characterized in that the method comprises: (1) Establish the information database of the distribution station area to be analyzed, and the information is used to judge whether the voltage of the distribution station area is low and make suggestions for improvement; the information library includes the electrical parameters of the equipment: the power distribution of the distribution station area The model capacity of the transformer, the phase number, model and length of each section of wire, the position and size of the main load; it also includes related economic parameters: equipment price, design and construction cost; (2) The Simulink simulation platform based on Matlab establishes the simulation model of distribution station area, and described simulation model is made up of three-phase 10kV AC power supply, three-phase distribution transformer, three-phase wire, three-phase load part, and described AC power connection The high-voltage end of the three-phase distribution transformer, the low-voltage end of the three-phase distribution transformer is connected to the three-phase load through a three-phase wire; the device in the model uses the Matlab program to assign values to its parameters; the assignment method is to write m files, Call the "set_param" function to assign the capacity of the distribution transformer, the impedance value of the wire, and the active and reactive power value of the load; (3) Edit the Matlab program to automatically read the information base of the distribution station area, use the "xlsread" command to read the file; and according to the information, use the assignment method in (2) to assign the simulation model, Including electrical parameters of distribution transformer, wire and load; (4) The simulation model assigns values to the model through the information base, displays the assigned parameters through a graphical user interface (GUI window), and flexibly changes distribution transformers, wires, Load parameters to help technicians design the distribution station area; (5) the simulation result of described simulation model is that the Simulink program of Matlab automatically simulates the built model according to the circuit principle, and obtains the voltage and current value of each set point of the model; if the simulation analysis carried out to a single power distribution station area, Display the simulation results through the GUI window, that is, the voltage value of each point and the output current value of the distribution transformer; if there is a low voltage problem, call the optimization program in the m file to automatically calculate and display the optimal solution; if you want to conduct a comprehensive analysis of a large number of stations For macroscopic understanding, if multiple stations need to be continuously analyzed, the file will be automatically generated, and the results will be output using "xlswrite". Each station puts forward the optimal solution; the calculation method of the optimal solution is to change the parameters of the device by calling the optimization program in the m file, so that the model changes from a low-cost model to a high-cost model, until the entire station voltage The obtained model device parameters are the optimal solution until qualified. 2. The method for judging the low voltage of the distribution station area according to claim 1, wherein the method for judging the low voltage of the distribution station area of the present invention comprises the following steps: (1) Select the simulation mode, including two modes: mode 1 is to analyze and simulate a single station area, which is mainly used to understand the status quo of a specific station area, or analyze renovation suggestions, or evaluate new plans; mode 2 is to analyze and simulate multiple stations Conduct a macro understanding of the district, compare the effects of different schemes, or analyze the most serious problem in the district, and provide decision-making basis for the arrangement and transformation plan of the power grid operation and maintenance management department; (2) If you choose a single analysis, you don’t need to input parameters from the database, you can directly input parameters from the edited GUI window, and the simulation results and optimal solution suggestions are also directly displayed through the GUI window, which is convenient and flexible; the simulation results displayed in the GUI window are the Voltage value, distribution transformer outlet current value; if there is a low voltage problem, call the optimization program in the m file, the obtained model device parameters are the optimal solution, automatically calculate and display the optimal solution; (3) If the batch analysis mode is selected, the simulation will be carried out in an automatic batch mode, and the results and the display of the optimal solution suggestion will be output in the form of a file. The output method is to use the "xlswrite" function to record the voltage deviation of each station area according to the simulation results. Low point, terminal voltage value, and comprehensive economic and technical effects to propose the optimal solution for each station area. 3. The method for judging the low voltage in the distribution station area according to claim 1, wherein the simulation model can carry out simulations in the following situations as required: (1) Low voltage conditions under different power factors; (2) Low voltage conditions under different load access rates; (3) Low voltage situations under different load models. 4. The method for judging low voltage in distribution station area according to claim 1, characterized in that the functions of the method can also be expanded, including the introduction of harmonic analysis, three-phase unbalance analysis, and reactive power compensation analysis. 5. The method for judging low voltage in distribution station area according to claim 1, characterized in that, said simulation models are all directly taken in the Powersystem component library of Simulink.