CN108732425B - A real-time monitoring method for resistance value of power supply lines in low-voltage distribution network - Google Patents

Abstract

The invention relates to a real-time monitoring method for the resistance value of the power supply line of a low-voltage distribution network, which utilizes the power consumption data acquisition function of a smart meter to collect the voltage and current values of the electric meters at each end point of the power supply line of the low-voltage distribution network in real time, so as to obtain the voltage of each end point of the power supply line of the low-voltage distribution network. , current value, and calculate the resistance value of each section of the low-voltage distribution network power supply line, so as to realize real-time monitoring of the resistance value of the low-voltage distribution network power supply line. The invention does not need to acquire the voltage and current data of each branch point of the low-voltage distribution network power supply line, and does not need to add monitoring equipment to the low-voltage distribution network. Whitespace.

Description

A real-time monitoring method for resistance value of power supply lines in low-voltage distribution network

technical field

The invention relates to the field of resistance value measurement of low-voltage distribution network power supply lines, in particular to a real-time monitoring method for the resistance value of low-voltage distribution network power supply lines.

Background technique

The change of the resistance value of the power supply line of the low-voltage distribution network can reflect whether the power supply line of the low-voltage distribution network is in good condition. It is an important physical parameter of the power supply line of the low-voltage distribution network. Its size directly affects the size of the line loss, and the voltage drop caused by it directly Affecting the voltage quality of end-users, a large number of low-voltage distribution network power supply line body failures are caused by too large resistance values, causing wires and their connected equipment to heat up and burn, thus affecting the benefits of power supply enterprises and the normal production and life of users. Therefore, the realization of power supply to low-voltage distribution networks Real-time monitoring of line resistance value is of great significance.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to propose a real-time monitoring method for the resistance value of the low-voltage distribution network power supply line, which does not need to obtain the voltage and current data of each branch point of the low-voltage distribution network power supply line, and does not need to add monitoring equipment to the low-voltage distribution network. , can be applied to real-time monitoring of low-voltage distribution network operating status, filling the gap in real-time monitoring of low-voltage distribution network operating status.

The present invention adopts the following scheme to realize: a real-time monitoring method for the resistance value of the power supply line of a low-voltage distribution network, which is characterized in that: it comprises the following steps:

Step S1: collect the voltage and current values of each end point of the low-voltage distribution network power supply line in real time;

Step S2: Calculate the real-time resistance value of each section of the low-voltage distribution network power supply line by using the values collected in step S1.

Further, step S1 specifically includes the following steps:

Step S11: Use the electricity meter data collection function to collect the voltage and current values of the electricity meter at the head of the low-voltage distribution network power supply line and all the user electricity meters at the end of the low-voltage distribution network power supply line in real time, and the collected voltage value of the electricity meter represents the low-voltage distribution network where the electricity meter is located. The voltage value of the power supply line, the collected current value of the meter represents the current value circulating on the power supply line of the low-voltage distribution network where the meter is located;

Step S12: Select several groups of values collected at different times, and the values in each group are not proportional.

Further, step S2 specifically includes the following steps:

Step S21: Calculate the voltage difference between the head end and the end of the low-voltage distribution network power supply line according to the voltage value collected in step S1;

Step S22: Calculate the current value circulating in each section of the low-voltage distribution network power supply line according to the current value collected in step S1;

Step S23: According to the data calculated in steps S21 and S22, and according to the following formula, establish a multivariate linear equation system with the unknown value of the resistance value of each section of the low-voltage distribution network power supply line:

U _{head end} - U _end = ∑I _n R _n ;

In the formula, _{the head end} of U represents the voltage at the head end of the low-voltage distribution network power supply line, the end of U represents the voltage at the _end of the low-voltage distribution network power supply line, ∑I _n R _n represents the sum of the voltage drops generated by each segment of the low-voltage distribution network power supply line, and I _n represents The current value flowing through the low-voltage distribution network power supply line, R _n represents the resistance value of each section of the low-voltage distribution network power supply line;

Step S24: Obtain the multivariate linear equation system in step S23 to obtain the resistance value R _n of each section of the low-voltage power supply line.

The invention utilizes the power consumption data acquisition function of the smart meter to collect the voltage and current values of the power meters at each end point of the low-voltage distribution network power supply line in real time, so as to obtain the voltage and current values of each end point of the low-voltage distribution network power supply line, and calculates each segment of the low-voltage distribution network power supply line. resistance value, so as to realize real-time monitoring of the resistance value of the power supply line of the low-voltage distribution network.

Compared with the prior art, the present invention has the following beneficial effects: the present invention does not need to acquire the voltage and current data of each branch point of the power supply line of the low-voltage distribution network, does not need to add monitoring equipment to the low-voltage distribution network, and can be applied to the low-voltage distribution network Real-time monitoring of operating status fills the gap in real-time monitoring of low-voltage distribution network operating status.

Description of drawings

FIG. 1 is a single-phase schematic diagram of a low-voltage distribution network power supply line in an embodiment of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

As shown in FIG. 1 , this embodiment provides a real-time monitoring method for the resistance value of a power supply line in a low-voltage distribution network, which is characterized by comprising the following steps:

Step S1: collect the voltage and current values of each end point of the low-voltage distribution network power supply line in real time;

Step S2: Calculate the real-time resistance value of each section of the low-voltage distribution network power supply line by using the values collected in step S1.

In this embodiment, step S1 specifically includes the following steps:

Step S11: Use the electricity meter data collection function to collect the voltage and current values of the electricity meter at the head of the low-voltage distribution network power supply line and all the user electricity meters at the end of the low-voltage distribution network power supply line in real time, and the collected voltage value of the electricity meter represents the low-voltage distribution network where the electricity meter is located. The voltage value of the power supply line, the collected current value of the meter represents the current value circulating on the power supply line of the low-voltage distribution network where the meter is located;

Step S12: Select several groups of values collected at different times, and the values in each group are not proportional.

In this embodiment, step S2 specifically includes the following steps:

Step S21: Calculate the voltage difference between the head end and the end of the low-voltage distribution network power supply line according to the voltage value collected in step S1;

Step S22: Calculate the current value circulating in each section of the low-voltage distribution network power supply line according to the current value collected in step S1;

Step S23: According to the data calculated in steps S21 and S22, and according to the following formula, establish a multivariate linear equation system with the unknown value of the resistance value of each section of the low-voltage distribution network power supply line:

U _{head end} - U _end = ∑I _n R _n ;

In the formula, _{the head end} of U represents the voltage at the head end of the low-voltage distribution network power supply line, the end of U represents the voltage at the _end of the low-voltage distribution network power supply line, ∑I _n R _n represents the sum of the voltage drops generated by each segment of the low-voltage distribution network power supply line, and I _n represents The current value flowing through the low-voltage distribution network power supply line, R _n represents the resistance value of each section of the low-voltage distribution network power supply line;

Step S24: Obtain the multivariate linear equation system in step S23 to obtain the resistance value R _n of each section of the low-voltage power supply line.

In this embodiment, the power consumption data collection function of the smart meter is used to collect the voltage and current values of the power meters at each end point of the low-voltage distribution network power supply line in real time, so as to obtain the voltage and current values of each end point of the low-voltage distribution network power supply line, and calculate the power supply of each segment of the low-voltage distribution network. Line resistance value, so as to realize real-time monitoring of the resistance value of the low-voltage distribution network power supply line.

As shown in Figure 1, this embodiment takes the single-phase line of the low-voltage distribution network power supply line as an example, and specifically includes the following steps:

1. Collect the voltage and current values of each end point of the low-voltage distribution network power supply line in real time;

(1) Use the electricity data collection function of the electricity meter to collect the voltage and current values of the electricity meter at the head of the low-voltage distribution network power supply line and all the user meters at the end of the low-voltage distribution network power supply line in real time. The voltage value of the power supply line, the collected current value of the meter represents the current value flowing on the power supply line of the low-voltage distribution network where the meter is located, and the voltage value at the head end a of the low-voltage distribution network power supply line shown in Figure 1 is recorded as U _a , namely The voltage value collected from the meter at the head end of the low-voltage distribution network power supply line, the voltage value at the end f of the low-voltage distribution network power supply line shown in Figure 1 is recorded as U _f , that is, collected from the user's meter at the end of the low-voltage distribution network power supply line. The voltage value at the end of the low-voltage power supply line shown in Figure 1 flows through the low-voltage distribution network power supply line where the meters are located at the f, g, h, i, j, k, l, m and n terminals The current values of I _f , I _g , I h , I i , I j , I k , I l , I m , and I n are respectively recorded as If , I g , I _h , I _i , I _j , I _k , I _l , I _m , and I _n , that is, the current values collected from the electric meters of the corresponding endpoints;

(2) Select several groups of values collected at different times, and the values of each group are not proportional.

2. Use the collected data to calculate the real-time resistance value of each section of low-voltage distribution network power supply lines. Take the calculation of the resistance values of the ab section, bc section, ce section, and df section of the low-voltage distribution network power supply line at the head end a to the end f end in Figure 1 as an example:

(1) Calculate the voltage difference between the head end and the end of the low-voltage distribution network power supply line according to the collected voltage value. As shown in Figure 1, the voltage difference between the head end a and the end f of the low-voltage distribution network power supply line is U _a -U _f ;

(2) Calculate the current value of each section of low-voltage distribution network power supply line according to the collected current value, and denote the current value of the low-voltage distribution network power supply line through the ab section, bc section, and cd section shown in Figure 1 as I respectively _ab , I _bc , I _cd , there are I _ab =I _f +I _g +I _h +I _i +I _j +I _k +I _l +I _m +I _n ,I _bc =I _f +I _g +I _h +I _i +I _j +I _k , I _cd =I _f +I _g +I _h , the current value passing through the low-voltage distribution network power supply line in the df section is I _df =I _f ;

(3) According to the obtained values, according to the formula U _{head end} - U _end = ∑I _n R _n , establish a multivariate linear equation system with the unknown resistance value of each section of the low-voltage distribution network power supply line. The resistance values of the low-voltage distribution network power supply lines in the ce section and the df section are respectively recorded as R _ab , R _bc , R _cd , and R _df . According to the formula, the equation U _a -U _f =I _ab R _ab +I _bc R _bc +I _cd can be obtained. R _cd +I _df R _df , select 4 groups of voltage and current values collected at different times, and the values in each group are not proportional. Substituting into the above formula can get _Rab , R _bc , R _cd , and R _df as four unknowns A system of quadratic linear equations composed of equations;

(4), solve the above-mentioned quaternary linear equations to obtain the resistance values R _ab , R _bc , R _cd , and R _df of each section of the low-voltage power supply line;

In the same way, the real-time resistance value of other low-voltage distribution network power supply lines can be calculated.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (1)

1. A real-time monitoring method for the resistance value of a power supply circuit of a low-voltage distribution network is characterized by comprising the following steps: the method comprises the following steps:

step S1: collecting the voltage and current values of each end point of a low-voltage distribution network power supply line in real time;

step S2: calculating the real-time resistance value of each section of low-voltage distribution network power supply line by using the value acquired in the step S1;

wherein, step S1 specifically includes the following steps:

step S11: the method comprises the steps that the voltage and current values of all user electric meters at the head end of a low-voltage distribution network power supply line and the tail end of the low-voltage distribution network power supply line are collected in real time by utilizing an electric meter electricity data collection function, the collected electric meter voltage value represents the voltage value of the low-voltage distribution network power supply line where the electric meter is located, and the collected electric meter current value represents the current value circulating on the low-voltage distribution network power supply line where the electric meter is located;

step S12: selecting a plurality of groups of values acquired at different times, wherein the values of each group are not proportional;

wherein, step S2 specifically includes the following steps:

step S21: calculating the voltage difference value between the head end and the tail end of the power supply line of the low-voltage distribution network according to the voltage value acquired in the step S1;

step S22: calculating the current value of each section of the low-voltage distribution network power supply line according to the current value collected in the step S1;

step S23: and establishing a multivariate linear equation set with the resistance value of each section of the low-voltage distribution network power supply line as an unknown number according to the data obtained by calculation in the steps S21 and S22 as follows:

U_{head end}-U_{End tip}＝∑I_nR_n；

In the formula of U_{Head end}Indicating the head end voltage, U, of the low-voltage distribution network power supply line_{End tip}Representing the end voltage of the supply line of a low-voltage distribution network, ∑ I_nR_nRepresents the sum of voltage drops generated by each section of low-voltage distribution network power supply line, I_nIndicating the value of the current flowing in the supply line of the low-voltage distribution network, R_nThe resistance value of each section of low-voltage distribution network power supply line is represented;

step S24: obtaining the resistance value R of each section of low-voltage power supply circuit by solving the multivariate linear equation set in the step S23_n。

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