CN118259091A - Method and device for measuring line loss of power supply line of low-voltage transformer area - Google Patents

Abstract

The present invention discloses a method and device for measuring line loss of a low-voltage power supply line. The method includes: constructing a first measurement system and a second measurement system, wherein a first standard electric energy sensor is provided on any outgoing line in the first measurement system, and the first standard electric energy sensor is used to obtain the error of the electric energy sensor on each outgoing line and the total electric energy sensor of the busbar incoming line; a second standard electric energy sensor is provided on the connecting line of any household electric energy sensor in the second measurement system, and the second standard electric energy sensor is used to obtain the error of the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box; a mathematical calculation model for the line loss rate of the low-voltage power supply line is constructed to obtain the line loss of the low-voltage power supply line. The present invention establishes a corresponding measurement system through the energy conservation relationship, and can accurately measure the line loss of the low-voltage power supply line.

Description

A method and device for measuring line loss of low voltage power supply lines

Technical Field

The present invention relates to the technical field of line loss of power supply system, and in particular to a method and device for measuring line loss of power supply lines in low-voltage substations.

Background technique

Accurately measuring the line loss of the low-voltage area of the power supply system is a very important task for the power system. The line loss of the low-voltage area power supply line is usually at a level of 1.0% or lower, while the measurement error of the electric energy metering device of the low-voltage area line under traditional technology is usually at a level of 3.5% or even higher. It is obviously not feasible to measure the line loss using the incoming and outgoing line electric energy metering devices of the low-voltage area busbar. The traditional and current technology of the existing power system industry uses the theoretical line loss calculation method to estimate the line loss of the power supply line. The accuracy of this estimation is extremely poor, and it is difficult to accurately measure the line loss of the low-voltage area power supply line. Since line loss monitoring involves safe power supply and economic benefits, it is of great significance to accurately measure the line loss of the low-voltage area power supply line.

In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the field of this technology.

Summary of the invention

The technical problem to be solved by the present invention is how to accurately measure the line loss of the power supply line in the low-voltage area.

The present invention adopts the following technical solution:

In the first aspect, the present invention proposes a method for measuring line loss of a low-voltage power supply line, wherein a first measurement system consisting of a total electric energy sensor of a low-voltage transformer busbar incoming line and a transmission line of electric energy sensors of each outgoing line satisfies a first electric energy conservation relationship, and a second measurement system consisting of a total electric energy sensor in an electric energy meter box at the end of each outgoing line and a transmission line of each household electric energy sensor satisfies a second electric energy conservation relationship, and the measurement method comprises:

A first standard electric energy sensor is arranged on any outgoing line in the first measurement system, and the first standard electric energy sensor is used to obtain the error of the electric energy sensors on each outgoing line and the total electric energy sensor of the bus incoming line;

A second standard electric energy sensor is arranged on the connection line of any household electric energy sensor in the second measurement system, and the second standard electric energy sensor is used to obtain the error between the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box;

Construct a mathematical calculation model for the line loss rate of the low-voltage power supply line to obtain the line loss of the low-voltage power supply line.

Preferably, the method of using the first standard electric energy sensor to obtain the errors of the electric energy sensors on each outgoing line and the total electric energy sensor of the bus incoming line specifically includes:

Calibrate the incoming line of the electric energy sensor connected in series on the outgoing line of the first standard electric energy sensor, and obtain the error of the electric energy sensor;

By utilizing the first law of conservation of electric energy, the voltage signal of the electric energy sensor on the outgoing line is switched back to obtain the true electric energy of the electric energy sensors on each outgoing line and the total electric energy sensor of the bus incoming line, and the electric energy sensors on each outgoing line and the total electric energy sensor of the bus incoming line are calibrated.

Preferably, the errors between the first standard electric energy sensor and the second standard electric energy sensor are acquired in advance by an error detection device to ensure that the first standard electric energy sensor and the second standard electric energy sensor can accurately measure data.

Preferably, the data acquisition system collects the power data of all lines in the low-voltage area, and the calculation system calculates the real power and power errors of the power sensors of all power supply lines based on the power data of all lines.

Preferably, the data acquisition system comprises at least one acquisition device, and the acquisition device is connected to the computing system to facilitate data transmission.

Preferably, all outgoing and incoming lines corresponding to the busbar are equipped with power sensors, and the data acquisition system is used to collect power data of the total power sensor of the busbar incoming line, all outgoing and incoming line power sensors and the first standard power sensor.

Preferably, all household power sensors in the low-voltage area are equipped with power sensors, and the data acquisition system is used to collect power data of the total power sensor in the power meter box, all household power sensors and the second standard power sensor.

Preferably, the computing system may be one or more of a circuit board corresponding to each electric energy sensor in the circuit, a cloud computing device in the cloud, and a computing server.

Preferably, the line loss rate mathematical calculation model formula is:

Wherein, _Xi represents the line loss of each i-th outgoing line, _Wki represents the actual electric energy of the i-th outgoing line, _Wki0 represents the actual electric energy of the total electric energy sensor in the electric energy meter box at the end of the i-th outgoing line, n represents the number of outgoing lines corresponding to the busbar, and _Xtotal represents the total actual line loss of the power supply line.

In a second aspect, relative to the first aspect, the present invention further proposes a device for measuring line loss of a low-voltage power supply line in a substation, the device being applicable to the method for measuring line loss of a low-voltage power supply line in a substation in the first aspect, the device comprising a first measuring system and a second measuring system; the first measuring system comprising a total power sensor for a busbar incoming line, a return line power sensor and a first standard power sensor; the second measuring system comprising a total power sensor, a household power sensor and a second standard power sensor in a return line power meter box;

A first standard electric energy sensor is connected in series to any outgoing line in the first measurement system, and a second standard electric energy sensor is connected in series to any connecting line of the household electric energy sensor in the second measurement system, so as to form a measuring device for the line loss of the low-voltage power supply line.

The present invention satisfies the first electric energy conservation relationship through the first measurement system formed by the total electric energy sensor of the main incoming line of the low-voltage transformer and the transmission line of the outgoing line electric energy sensor, and the second measurement system formed by the total electric energy sensor in the electric energy meter box at the end of each outgoing line and the transmission line of each household electric energy sensor satisfies the second electric energy conservation relationship. By switching the voltage signal of the electric energy sensor of the household electric energy, the first electric energy conservation relationship and the second electric energy conservation relationship are used to obtain the true electric energy and error of the total electric energy sensor of the main incoming line and the true electric energy and error of the computer sensor of each outgoing line, as well as the true electric energy and error of the total electric energy sensor in the electric energy meter box at the end of each outgoing line and the electric energy sensor of each household, and then the line loss of the low-voltage power supply line is obtained by constructing a mathematical calculation model of the line loss rate of the low-voltage area power supply line. The line loss measured by the present invention can theoretically accurately measure the line loss of the low-voltage power supply line, so that the accuracy of the line loss measurement meets the actual needs.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG1 is a flow chart of a method for measuring line loss of a low-voltage power supply line provided by the present invention;

2 is a circuit diagram of a method for detecting an error in electric energy data of a low-voltage power supply line in a low-voltage power supply line loss measurement method provided by the present invention;

3 is a circuit diagram of a method for transmitting electric energy data between phases in a low-voltage power supply area according to a method for measuring line loss in a low-voltage power supply area provided by the present invention;

4 is a schematic diagram of a method for measuring line loss of a low-voltage power supply line in a low-voltage power supply area provided by the present invention;

FIG. 5 is a circuit diagram of a method for measuring line loss of a low-voltage power supply line provided by the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

In the description of the present invention, the terms "inside", "outside", "longitudinal", "lateral", "upper", "lower", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Embodiment 1:

Embodiment 1 of the present invention provides a method for measuring line loss of a low-voltage power supply line. A first measurement system composed of a total electric energy sensor of a low-voltage transformer busbar incoming line and a transmission line of electric energy sensors of each outgoing line satisfies a first electric energy conservation relationship, and a second measurement system composed of a total electric energy sensor in an electric energy meter box at the end of each outgoing line and a transmission line of each household electric energy sensor satisfies a second electric energy conservation relationship. As shown in FIG1 , the measurement method includes:

Step 201: a first standard electric energy sensor is provided on any outgoing line in the first measurement system, and the first standard electric energy sensor is used to obtain errors of electric energy sensors on each outgoing line and a total electric energy sensor on the bus incoming line.

As shown in Figure 2, a circuit diagram of a method for detecting errors in electric energy data of the inlet and outlet lines of a low-voltage substation bus is shown, wherein Wk represents the electric energy sensors of the bus and each outgoing line (such as Wk0, Wk1, Wk2, Wk3, ..., Wkn, wherein Wk0 represents the electric energy sensor of the bus), and Wbzb represents the first standard electric energy sensor provided on any outgoing line corresponding to the low-voltage substation bus. The law of conservation of energy is satisfied between the electric energy sensors of the substation bus and all outgoing line electric energy sensors in the first measurement system of an embodiment of the present invention. Taking the first measurement system containing n outgoing lines as an example, a first standard electric energy sensor is connected in series to any outgoing line on the n outgoing lines. When the first standard electric energy sensor is connected in series with the electric energy sensor on the corresponding return line, theoretically, the true value of the electric energy of the first standard electric energy sensor is equal to that of the electric energy sensor on the corresponding return line, and the electric energy value measured by the first standard electric energy sensor is the standard value. The first standard electric energy sensor is compared with the value of the electric energy sensor in the corresponding return line, and the electric energy difference between the first standard electric energy sensor and the electric energy sensor of the corresponding return line is divided by the electric energy of the first standard electric energy sensor to calculate the error of the electric energy sensor on the corresponding return line (the electric energy sensor connected in series with the first standard electric energy sensor) and calibrate it by adjustment.

Among them, the use of the first standard electric energy sensor in the embodiment of the present invention to obtain the error of the electric energy sensor on each outgoing line and the total electric energy sensor of the bus incoming line specifically includes: using the first standard electric energy sensor to calibrate the electric energy sensor incoming line connected in series on the outgoing line, and obtaining the error of the electric energy sensor; using the first electric energy conservation law, by switching the voltage signal of the electric energy sensor of the outgoing line, obtaining the real electric energy of the electric energy sensor on each outgoing line and the total electric energy sensor of the bus incoming line, and calibrating the electric energy sensor on each outgoing line and the total electric energy sensor of the bus incoming line, and obtaining the error of the electric energy sensor on each outgoing line and the total electric energy sensor of the bus incoming line. As shown in Figure 2, the total electric energy sensor of the substation bus in the first measurement system of the embodiment of the present invention and the electric energy sensor of the n-way outgoing line satisfy the law of conservation of energy, that is, the real electric energy of the total electric energy sensor in the bus incoming line is equal to the sum of the real electric energy of the electric energy sensors of all outgoing lines. For the sake of convenience, it is assumed that the standard electric energy sensor is connected in series with the electric energy sensor on the first outgoing line (during actual measurement, the standard electric energy sensor may also be connected in series on other outgoing lines, such as the second outgoing line).

In an optional manner, the error and true data of each electric energy sensor can be obtained in the following manner: in the actual measurement process, the electric energy sensor on the first outgoing line is first calibrated using a standard electric energy sensor, and then the first outgoing line is kept open, and the other outgoing lines are switched to a disconnected state. At this time, only the total electric energy sensor of the bus incoming line and the electric energy sensor of the first outgoing line are in the connected state in the first measurement system. According to the law of conservation of electric energy, the true electric energy of the total electric energy sensor of the bus incoming line is equal to the true electric energy of the electric energy sensor on the first outgoing line. Among them, the electric energy sensor on the first outgoing line is connected in series with the standard electric energy sensor. After the electric energy sensor on the first outgoing line is calibrated by the standard electric energy sensor, it can also be considered as a standard electric energy sensor. The electric energy sensor on the first outgoing line is used to calibrate the total electric energy sensor on the bus incoming line. After the total electric energy sensor on the bus incoming line is calibrated, the total electric energy sensor of the bus incoming line and the electric energy sensor on the second outgoing line form a corresponding measurement system (except for the second outgoing line, other outgoing lines are in a disconnected state), and the total electric energy sensor after the bus incoming line calibration is used to calibrate the electric energy sensor on the second outgoing line; then the electric energy sensors on other outgoing lines are calibrated one by one in the same way until all the electric energy sensors on the outgoing lines are calibrated. It is worth noting that during the calibration, the errors of all outgoing line electric energy sensors and the error of the total electric energy sensor of the bus incoming line are obtained. The voltage signal of the electric energy sensor switched back to the outgoing line described in the embodiment of the present invention indicates the process of making the electric energy of the electric energy sensor of each outgoing line different values, or switching the corresponding line on and off. As shown in Figure 2, the 1-way incoming line and n-way split-phase lines of the low-voltage substation bus in the embodiment of the present invention are regarded as an independent "1-in n-out" electric energy conservation system, and a mathematical model for solving the electric energy data error can be established as follows:

In formula (1), k = a, b, c, the sub-meter represents the three phases abc, _Wk0 and _Xk0 represent the total electric energy of each phase and its data error, _Wki and _Xki represent the electric energy of the i-th outgoing line of each phase and its data error, _Wkbz and _Xkbz represent the standard electric energy of each phase and its data error, and _Wkbz and _Xkbz can be known or obtained by measurement and calculation.

From the perspective of the law of conservation of energy, it can be known that the true electric energy of the total electric energy sensor of the bus in the first measurement system of the present invention is equal to the sum of the true electric energy of the electric energy sensors of all outgoing lines (including n outgoing lines). After calibrating the electric energy sensors of each outgoing line using a standard electric energy sensor and calculating the true electric energy in each outgoing line, the true electric energy of the total electric energy sensor of the bus can be known through the law of conservation of energy, that is, the true electric energy of the total electric energy sensor of the bus is the sum of the true electric energy of the electric energy sensors of each outgoing line. After obtaining the true electric energy of the total electric energy sensor of the bus, the electric energy sensor set on the bus is used to obtain the measurement value, and the difference of the total electric energy sensor of the bus is calculated, thereby realizing the calibration of the total electric energy sensor of the bus.

Step 202: A second standard electric energy sensor is provided on the connection line of any household electric energy sensor in the second measurement system, and the second standard electric energy sensor is used to obtain the error between the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box.

A second standard electric energy sensor is arranged on the connection line of any household electric energy sensor in the second measurement system. The second standard electric energy sensor is used to calibrate the corresponding household electric energy sensor and obtain the error of the corresponding household electric energy sensor.

As shown in FIG3, a circuit diagram of the method for transmitting electric energy data of each phase component in a low-voltage substation is shown, wherein FIG3 represents the total electric energy sensor in the electric energy meter box at the end of the i-th return line and the electric energy sensors of each household (such as: Wki0, Wki1, Wki2, Wki3, ..., Wkin, wherein Wki0 represents the total electric energy sensor in the electric energy meter box at the end of the return line, i = 1, 2, ..., n). Since the standard electric energy sensor connected in series on any household has the same function as the standard electric energy sensor set on the return line, FIG3 uses the same reference numeral Wbzb to represent the standard electric energy sensor. For the convenience of explanation, it is assumed that the standard electric energy sensor is connected in series with the electric energy sensor on the first household (during actual measurement, the standard electric energy sensor can also be connected in series on other households, for example, the standard electric energy sensor is connected in series on the line of the second household); the total electric energy sensor in the electric energy meter box at the end of the return line in the second measurement system of the embodiment of the present invention and the electric energy sensors of each household satisfy the law of conservation of energy. Taking the example of n household electric energy sensors installed in the electric energy meter box of the i-th channel in the second measurement system, a standard electric energy sensor is installed in the electric energy sensor of the first household among the n households in the second measurement system; theoretically, the real electric energy of the standard electric energy sensor is equal to that of the electric energy sensor of the first household, and the electric energy value measured by the standard electric energy sensor is the standard value. The value of the standard electric energy sensor is compared with that of the electric energy sensor of the first household, and the error (actually the error percentage) of the electric energy sensor of the first household in the second measurement system is calculated by dividing the difference in electric energy measured by the standard electric energy sensor and the electric energy sensor of the first household by the electric energy of the standard electric energy sensor, and the electric energy of the first household is calibrated by adjustment.

Among them, the use of the second standard electric energy sensor in the embodiment of the present invention to obtain the error of the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box specifically includes: using the second standard electric energy sensor to calibrate the electric energy sensor input line connected in series on the household line, and obtain the error of the electric energy sensor; using the second electric energy conservation law, by switching the voltage signal of the electric energy sensor of the electric energy household, the real electric energy of the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box at the end of each outgoing line is obtained, and the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box at the end of each outgoing line are calibrated to obtain the error of the electric energy sensor of each household and the total electric energy sensor in the electric energy meter box. In the process of actually measuring the electric energy sensors of each household, the embodiment of the present invention first uses the second standard electric energy sensor to calibrate the electric energy sensor on the first household, then keeps the first household connected, and switches the other households to the disconnected state. At this time, only the total electric energy sensor in the electric energy meter box at the end of the return line and the electric energy sensor of the first household are in the connected state in the second measurement system. According to the law of conservation of electric energy, the real electric energy of the total electric energy sensor in the electric energy meter box at the end of the return line is equal to the real electric energy of the electric energy sensor on the first household. Among them, the electric energy sensor on the first household is connected in series with the standard electric energy sensor. After the electric energy sensor on the first household is calibrated by the standard electric energy sensor, it can also be considered as a standard electric energy sensor. The electric energy sensor on the first household is used to calibrate the total electric energy sensor in the electric energy meter box at the end of the return line. After the total electric energy sensor in the electric energy meter box at the end of the return line is calibrated, the total electric energy sensor in the electric energy meter box at the end of the return line and the electric energy sensor on the second sub-household form a corresponding measurement system (except for the second sub-household passage, other sub-households are in a disconnected state), and the total electric energy sensor in the electric energy meter box at the end of the return line is used to calibrate the electric energy sensor on the second sub-household; then the same method is adopted to calibrate the electric energy sensors on other sub-households one by one until all the electric energy sensors on the sub-households are calibrated. It is worth noting that during the calibration, the errors of all sub-household electric energy sensors and the error of the total electric energy sensor in the electric energy meter box at the end of the return line are obtained. The voltage signal of the electric energy sensor switched to the return line described in the embodiment of the present invention actually represents the switching process of the electric energy sensors of each sub-household or the corresponding lines.

From the perspective of the law of conservation of energy, it can be known that the real electric energy of the total electric energy sensor in the electric energy meter box at the end of the return line in the second measurement system of the present invention is equal to the sum of the real electric energy of the electric energy sensors of all the sub-households (including n return lines). After the electric energy sensors of the sub-households are calibrated using standard electric energy sensors and the real value of the electric energy of the electric energy sensors of each sub-household is calculated, the real electric energy of the total electric energy sensor in the electric energy meter box at the end of the return line can be known through the law of conservation of energy, that is, the real electric energy of the total electric energy sensor in the electric energy meter box at the end of the return line is equal to the sum of the real electric energy of the electric energy sensors of each sub-household. After obtaining the real electric energy of each household's electric energy sensor, the measurement value is obtained by using each household's electric energy sensor, and the difference between the measurement value of each household's electric energy sensor and the real electric energy measured by the standard electric energy sensor is calculated, thereby realizing the calibration of each household's electric energy sensor; the real electric energy of the total electric energy sensor in the electric energy meter box at the end of the return line in the second measurement system can be calculated through the second law of conservation of electric energy, which is equal to the sum of the real electric energy of all household's electric energy sensors (calibrated by standard electric energy sensors). It is worth noting that the first law of conservation of electric energy and the second law of conservation of electric energy described in the present invention are actually artificially divided, and actually both conform to the law of conservation of energy.

Step 203: construct a mathematical calculation model for the line loss rate of the low-voltage area power supply line to obtain the line loss of the low-voltage area power supply line.

Among them, as shown in Figure 4, it is a schematic diagram of the line loss measurement method of the low-voltage power supply line in the embodiment of the present invention. The line loss in the embodiment of the present invention is mainly concentrated on the line between the head end (the end close to the bus) and the end of the return line corresponding to the low-voltage transformer bus. Each return line can be regarded as a line loss rate data calculation model. By obtaining the true value of the data electric energy of the first section and the end of each return line, the electric energy data of the line loss is calculated, and then the line loss rate is calculated. As shown in Figure 4, the formula of the mathematical calculation model of the line loss rate in the embodiment of the present invention is:

Among them, _Xi represents the line loss of each i-th outgoing line, _Wki represents the actual electric energy of the i-th outgoing line, _Wki0 represents the actual electric energy of the total electric energy sensor in the electric energy meter box at the end of the i-th outgoing line, n represents the number of outgoing lines corresponding to the busbar, and _Xtotal represents the total actual line loss of the power supply line. The total line loss rate and the sum of the line loss electric energy of the low-voltage power supply line can be calculated through the line loss rate data calculation model formula.

In the embodiment of the present invention, high-precision electric energy data at both ends of the power supply line is obtained through error compensation, and the actual line loss of the power supply line can be calculated using the high-precision electric energy data at both ends of the power supply line.

In order to illustrate the complete solution of the present invention, the specific details of the present invention are explained in detail below. Further, in order to ensure that the standard electric energy sensor of the embodiment of the present invention can measure the true value of the electric energy sensor and the household electric energy sensor on the corresponding return line, the error of the first standard electric energy sensor and the second standard electric energy sensor in the embodiment of the present invention is obtained in advance through an error detection device to ensure that the first standard electric energy sensor and the second standard electric energy sensor can accurately measure data. The first standard electric energy sensor and the second standard electric energy sensor can be calibrated using, but not limited to, existing circuits to ensure that accurate electric energy can be measured when calibrating the return line and each household electric energy sensor.

In order to simplify the measurement and calculation of the embodiment of the present invention, the embodiment of the present invention also includes a data acquisition system and a calculation system. The data acquisition system collects the electric energy data of all lines in the low-voltage area, and the calculation system calculates the real electric energy and electric energy error of the electric energy sensors of all power supply lines based on the electric energy data of all lines. The measuring devices in the first measurement system and the second measurement system are collected by the data acquisition system, and the electric energy data of all lines collected in the low-voltage area, as well as the electric energy data of the first standard electric energy sensor and the second standard electric energy sensor are calculated by the calculation system to obtain the real electric energy and electric energy error of the electric energy sensors of all power supply lines. The electric energy on all return lines and the electric energy of each household (each line corresponds to an electric energy meter box, and each electric energy meter box corresponds to n household electric energy sensors) are measured by the data acquisition system. Among them, the data collected by the data acquisition system of the embodiment of the present invention is the electric energy of the electric energy sensor of each incoming and outgoing line, the electric energy of the standard electric energy sensor (including the first standard electric energy sensor and the second standard electric energy sensor), the electric energy of the total electric energy sensor of the bus incoming line, the electric energy of the total electric energy sensor of the electric energy meter box, and the electric energy of each household electric energy sensor. After the data is collected by the data acquisition system, the data information is input into the corresponding calculation system, and the actual line loss and line loss rate calculation formula of the line loss rate calculation mathematical model of the low-voltage power supply line can be used to calculate the actual bus loss value and line loss rate of the present invention. It is worth noting that the data acquisition system described in the embodiment of the present invention includes at least one acquisition device, and the acquisition device is connected to the calculation system to facilitate data transmission.

Furthermore, all outgoing lines corresponding to the busbar in the embodiment of the present invention are equipped with electric energy sensors, and the data acquisition system is used to collect electric energy data of the total electric energy sensor of the busbar incoming line, the electric energy sensors of all outgoing lines, and the first standard electric energy sensor. The electric energy collected by the first standard electric energy sensor and the second standard electric energy sensor can be considered as the real electric energy value; the electric energy collected by the electric energy sensors other than the first standard electric energy sensor and the second standard electric energy sensor is a measured value, which has a certain error. The error value of each electric energy sensor can be obtained through the measurement values of the standard electric energy sensor and other electric energy sensors (electric energy sensors other than the standard electric energy sensor), and the total electric energy sensor of the busbar, the electric energy sensors of each outgoing line, the total electric energy sensor in the electric energy meter box at the end of each outgoing line, and the electric energy sensor of each household are calibrated to prepare for the subsequent accurate measurement of the real electric energy of the corresponding line.

Similarly, all household electric energy sensors in the low-voltage substation of the embodiment of the present invention are equipped with electric energy sensors, and the data acquisition system is used to collect electric energy data of the total electric energy sensor in the electric energy meter box, all household electric energy sensors and the second standard electric energy sensor, and then calibrate each household electric energy sensor and the total electric energy sensor in the electric energy meter box. The calibration process of each household electric energy sensor and the total electric energy sensor in the electric energy meter box has been described above and will not be repeated here. It is worth noting that the data acquisition system described in the embodiment of the present invention can be one or more of the circuit boards corresponding to each electric energy sensor in the line, the cloud computing equipment in the cloud, and the computing system can be one or more of the circuit boards corresponding to each electric energy sensor in the line, the cloud computing equipment in the cloud, and the computing server, and the specific selection is made according to the actual situation.

The present invention satisfies the first electric energy conservation relationship through the first measurement system formed by the total electric energy sensor of the main incoming line of the low-voltage transformer and the transmission line of the outgoing line electric energy sensor, and the second measurement system formed by the total electric energy sensor in the electric energy meter box at the end of each outgoing line and the transmission line of each household electric energy sensor satisfies the second electric energy conservation relationship. By switching the voltage signal of the electric energy sensor of the household electric energy, the first electric energy conservation relationship and the second electric energy conservation relationship are used to obtain the true electric energy and error of the total electric energy sensor of the main incoming line and the true electric energy and error of the computer sensor of each outgoing line, as well as the true electric energy and error of the total electric energy sensor in the electric energy meter box at the end of each outgoing line and the electric energy sensor of each household, and then the line loss of the low-voltage power supply line is obtained by constructing a mathematical calculation model of the line loss rate of the low-voltage area power supply line. The line loss measured by the present invention can theoretically accurately measure the line loss of the low-voltage power supply line, so that the accuracy of the line loss measurement meets the actual needs.

The present invention utilizes error measurement and compensation of electric energy data to obtain high-precision electric energy data of three-phase and single-phase low-voltage power supply line routes, and calculates line losses of three-phase and single-phase power supply lines. Specifically, accurate single-phase electric energy data and data from standard electric energy sensors are utilized to implement error measurement and compensation of split-phase electric energy data, and error measurement and compensation of three-phase electric energy data are implemented through combined-phase calculation, and high-precision electric energy data of three-phase and single-phase low-voltage power supply line routes are obtained, thereby realizing detection and monitoring of line losses of three-phase and single-phase low-voltage power supply line routes.

Embodiment 2:

Compared with the first embodiment of the present invention, the embodiment of the present invention further proposes a device for measuring line loss of a low-voltage power supply line in a substation, comprising a first measuring system and a second measuring system; the first measuring system comprises a total power sensor of a busbar incoming line, a return line power sensor and a first standard power sensor; the second measuring system comprises a total power sensor in a return line power meter box, a household power sensor and a second standard power sensor;

A first standard electric energy sensor is connected in series to any outgoing line in the first measurement system, and a second standard electric energy sensor is connected in series to any connecting line of the household electric energy sensor in the second measurement system, so as to form a measuring device for the line loss of the low-voltage power supply line.

As shown in Figure 5, a complete schematic diagram of the line loss measurement method for low-voltage power supply lines in an embodiment of the present invention is shown. A standard electric energy sensor is connected in series to each of the lines of the electric energy sensors in the first measurement system and the second measurement system of the embodiment of the present invention, and each electric energy sensor originally set on the line (including the electric energy sensor of the return line and the electric energy sensor of each household) is calibrated by the standard electric energy sensor to obtain the real electric energy of each electric energy sensor, and the corresponding line loss is finally calculated by the real electric energy. The line loss measurement and calculation method based on the embodiment of the present invention has been described in detail in Example 1, and will not be repeated here.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides a measurement method of low-voltage transformer district power supply line loss, its characterized in that, the total electric energy sensor of low-voltage transformer district transformer busbar inlet wire and the transmission line that each returns out line electric energy sensor constitute first measurement system satisfy first electric energy conservation relation, and the total electric energy sensor of each back out line terminal electric energy meter case and the transmission line that each divides home electric energy sensor constitute second measurement system satisfy second electric energy conservation relation, the measurement method includes:

a first standard electric energy sensor is arranged on any return line in the first measurement system, and the error of the electric energy sensor on each outlet line and the error of the total electric energy sensor of the bus inlet line are obtained by using the first standard electric energy sensor;

A second standard electric energy sensor is arranged on a connecting line of any household electric energy sensor in the second measurement system, and the second standard electric energy sensor is utilized to obtain the electric energy sensor of each household and the error of the total electric energy sensor in the electric energy meter box;

And constructing a mathematical calculation model of the line loss rate of the low-voltage area power supply line, and obtaining the line loss of the low-voltage area power supply line.

2. The method for measuring the line loss of the power supply line of the low-voltage transformer area according to claim 1, wherein the step of obtaining the error of the total power sensor of the power sensor on each outgoing line and the bus incoming line by using the first standard power sensor specifically comprises the steps of:

calibrating an incoming line of the electric energy sensor connected in series on a return line of the first standard electric energy sensor, and acquiring an error of the electric energy sensor;

And acquiring the real electric energy of the electric energy sensor on each outgoing line and the total electric energy sensor of the bus incoming line by utilizing the first electric energy conservation and through the voltage signal of the electric energy sensor switched back to the outgoing line, and calibrating the electric energy sensor on each outgoing line and the total electric energy sensor of the bus incoming line.

3. The method for measuring line loss of power supply line of low voltage transformer area according to claim 1, wherein the errors of the first standard power sensor and the second standard power sensor are obtained in advance by an error detection device, so as to ensure accurate measurement data of the first standard power sensor and the second standard power sensor.

4. The method for measuring the line loss of the power supply line of the low-voltage transformer area according to claim 1, wherein the data acquisition system acquires the electric energy data of all lines in the low-voltage transformer area, and the calculation system calculates the actual electric energy and the electric energy error of the electric energy sensors of all the power supply lines according to the electric energy data of all the lines.

5. The method of claim 4, wherein the data acquisition system comprises at least one acquisition device, and wherein the acquisition device is coupled to the computing system to facilitate data transmission.

6. The method for measuring the line loss of the power supply line of the low-voltage transformer area according to claim 4, wherein the electric energy sensors are arranged on all the return lines corresponding to the bus, and the data acquisition system is used for acquiring the electric energy data of the total electric energy sensor, all the return line electric energy sensors and the first standard electric energy sensor of the bus.

7. The method for measuring the line loss of the power supply line of the low-voltage transformer area according to claim 4, wherein the electric energy sensors are assembled on all household electric energy sensors in the low-voltage transformer area, and the data acquisition system is used for acquiring electric energy data of the total electric energy sensor, all household electric energy sensors and the second standard electric energy sensor in the electric energy meter box.

8. The method for measuring line loss of a low-voltage transformer area power supply line according to claim 4, wherein the computing system is one or more of a circuit board, cloud computing equipment and a computing server corresponding to each electric energy sensor in the line.

9. The method for measuring the line loss of the power supply line of the low-voltage transformer area according to claim 1, wherein the mathematical calculation model formula of the line loss rate is:

Wherein, X _i represents the line loss of each ith return line, W _ki represents the actual electric energy of the ith return line, W _ki0 represents the actual electric energy of the total electric energy sensor in the electric energy meter box at the tail end of the ith return line, n represents the number of the return lines corresponding to the bus, and X _{Total (S)} represents the total actual line loss of the power supply line.

10. The measuring device for the line loss of the power supply line of the low-voltage transformer area is characterized by being suitable for the measuring method for the line loss of the power supply line of the low-voltage transformer area according to any one of claims 1 to 9, and comprises a first measuring system and a second measuring system; the first measurement system comprises a total electric energy sensor of a bus incoming line, a return line electric energy sensor and a first standard electric energy sensor; the second measurement system comprises a total electric energy sensor, a household electric energy sensor and a second standard electric energy sensor in the return line electric energy meter box;

any return line in the first measurement system is connected with a first standard electric energy sensor in series, and a connecting line of any household electric energy sensor in the second measurement system is connected with a second standard electric energy sensor in series to form a measurement device of the line loss of the low-voltage station power supply line.