A multifunctional electric meter for calculating line loss through four-wire system

Abstract

The present invention discloses a multifunctional electric meter for calculating line loss through a four-wire system, comprising a central processing unit and an electric energy sampling unit electrically connected to the central processing unit, an electric energy calculation unit, a data storage unit, a voltage and current monitoring unit, an information input and output unit, and a line loss calculation unit. The present invention discloses a multifunctional electric meter for calculating line loss through a four-wire system, and the present invention discloses a multifunctional electric meter for calculating line loss through a four-wire system. By adding two voltage lines, the energy passing through the end of the cable is collected, thereby accurately measuring the energy lost in the cable. This allows users to remove the energy lost on the cable in real time to obtain the energy actually used, which is convenient for energy management and charging.

Description

Technical Field

[0001] The invention belongs to the field of electric power metering, and in particular relates to a multifunctional electric meter for calculating line loss through a four-wire system. Background Art

[0002] There will be losses in the cables during power transmission. Among the existing similar technologies, there are methods for calculating the electric energy lost in the cables through the resistance and current of the conductors, methods for calculating line losses using the equivalent relationship between the maximum value and the root mean square of the daily load curve, and methods for calculating the consumed electric energy through the root mean square current flowing through the line. The above methods are not measured by precise measurement, and the calculation accuracy is not high. They cannot be used as a standard for users who need to accurately calculate the cable loss energy.

[0003] Therefore, further improvements are made to the above problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a multifunctional electric meter for calculating line loss through a four-wire system, and to collect energy passing through the end of the cable by adding two voltage wires, thereby accurately measuring the energy lost by the cable. This allows users to remove the energy lost on the cable in real time to obtain the energy actually used, which is convenient for energy management and charging.

[0005] To achieve the above object, the present invention provides a multifunctional electric meter for calculating line loss through a four-wire system, comprising a central processing unit and an electric energy sampling unit, an electric energy calculation unit, a data storage unit, a voltage and current monitoring unit, an information input and output unit and a line loss calculation unit electrically connected to the central processing unit, wherein;

[0006] The central processing unit is used to coordinate the work of various units;

[0007] The electric energy sampling unit is used to process the collection function of basic data including voltage, current, active and reactive power;

[0008] The electric energy calculation unit performs statistics and calculations based on the sampled basic data, thereby obtaining real-time electric quantity data;

[0009] The data storage unit is used to store relevant data of the electric meter;

[0010] The voltage and current monitoring unit is used to detect voltage and current values ​​in real time;

[0011] The information input and output unit is used to manage functions including key input, liquid crystal display, pulse output, and power supply and disconnection;

[0012] The line loss calculation unit measures terminal voltage and power, integrates time, and measures electric energy.

[0013] As a further preferred technical solution of the above technical solution, for the line loss calculation unit, by adding two voltage wires to the end of the cable (for example, the electric meter is installed on the charging pile, and two wires are added to the cable of the charging gun head, and the line loss is the loss of the cable connected between the charging pile and the charging gun head), the voltage value at the end of the cable is collected to calculate the line loss energy (compared with ordinary DC, two voltage collection wires are added, so it is called a four-wire system), which is specifically implemented as follows:

[0014] The power at the cable inlet is calculated by collecting the voltage at the cable inlet, and the energy passing through the cable inlet is obtained by integrating the power at the cable inlet with respect to time:

[0015] P 线缆进端 =U 线缆进端 *I;

[0016] E 线缆进端 =∫P 线缆进端 (t)dt;

[0017] The power at the end of the cable is calculated by collecting the voltage at the end of the cable, and the energy passing through the end of the cable is obtained by integrating the power at the end of the cable over time:

[0018] P 线缆末端 =U 线缆末端 *I;

[0019] E 线缆末端 =∫P 线缆末端 (t)dt;

[0020] After obtaining the energy at the cable entrance and the energy at the cable end, subtract them to get the cable loss energy:

[0021] E 损耗 =E 进端 -E 末端 .

[0022] As a further preferred technical solution of the above technical solution, the current loop is connected to the current sampling loop of the electric meter, the voltage at the incoming end of the cable is connected to the voltage sampling loop of the electric meter (located in the electric energy sampling unit), and the energy at the incoming end of the cable is obtained through current sampling and voltage sampling;

[0023] The voltage at the end of the cable is connected to the line loss compensation sampling loop (located in the line loss metering unit, the line loss supplement sampling loop is used to collect the voltage value at the end of the cable) to obtain the terminal voltage value, and then the power at the end of the cable is calculated through the current value. The power is integrated over time to obtain the energy at the end of the cable. The line loss energy is obtained by subtracting the energy at the end of the cable from the energy at the cable input.

[0024] As a further preferred technical solution of the above technical solution, the multi-function meter is installed on the charging column, and the two voltage wires are connected between the multi-function meter (i.e., the cable input end) and the charging gun head (i.e., the cable end).

[0025] As a further preferred technical solution of the above technical solution, the current on the same cable is the same, and the voltage at different points is different. The line loss energy is calculated by collecting data at the input and output ends of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the multifunctional electric meter of the present invention.

[0027] Figure 2 It is a schematic diagram of the installation of the multifunctional electric meter of the present invention. DETAILED DESCRIPTION

[0028] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0029] In the preferred embodiments of the present invention, those skilled in the art should note that the charging pile, charging gun head, etc. involved in the present invention can be regarded as prior art.

[0030] Preferred embodiments.

[0031] like Figure 1-2 As shown, the present invention discloses a multifunctional electric meter for calculating line loss through a four-wire system, comprising a central processing unit and an electric energy sampling unit, an electric energy calculation unit, a data storage unit, a voltage and current monitoring unit, an information input and output unit and a line loss calculation unit electrically connected to the central processing unit, wherein;

[0032] The central processing unit is used to coordinate the work of various units;

[0033] The electric energy sampling unit is used to process the collection function of basic data including voltage, current, active and reactive power;

[0034] The electric energy calculation unit performs statistics and calculations based on the sampled basic data, thereby obtaining real-time electric quantity data;

[0035] The data storage unit is used to store relevant data of the electric meter;

[0036] The voltage and current monitoring unit is used to detect voltage and current values ​​in real time;

[0037] The information input and output unit is used to manage functions including key input, liquid crystal display, pulse output, and power supply and disconnection;

[0038] The line loss calculation unit measures terminal voltage and power, integrates time, and measures electric energy.

[0039] Specifically, for the line loss calculation unit, by adding two voltage wires to the end of the cable (for example, the electric meter is installed on the charging pile, and two wires are added to the cable of the charging gun head, and the line loss is the loss of the cable connected between the charging pile and the charging gun head), the voltage value at the end of the cable is collected to calculate the line loss energy (compared with ordinary DC, two voltage collection wires are added, so it is called a four-wire system), which is specifically implemented as follows:

[0040] The power at the cable inlet is calculated by collecting the voltage at the cable inlet, and the energy passing through the cable inlet is obtained by integrating the power at the cable inlet with respect to time:

[0041] P 线缆进端 =U 线缆进端 *I;

[0042] E 线缆进端 =∫P 线缆进端 (t)dt;

[0043] The power at the end of the cable is calculated by collecting the voltage at the end of the cable, and the energy passing through the end of the cable is obtained by integrating the power at the end of the cable over time:

[0044] P 线缆末端 =U 线缆末端 *I;

[0045] E 线缆末端 =∫P 线缆末端 (t)dt;

[0046] After obtaining the energy at the cable entrance and the energy at the cable end, subtract them to get the cable loss energy:

[0047] E 损耗 =E 进端 -E 末端 .

[0048] More specifically, the current loop is connected to the current sampling loop of the electric meter, and the voltage at the cable input end is connected to the voltage sampling loop of the electric meter (located in the electric energy sampling unit), and the energy at the cable input end is obtained through current sampling and voltage sampling;

[0049] The voltage at the end of the cable is connected to the line loss compensation sampling loop (located in the line loss metering unit, the line loss supplement sampling loop is used to collect the voltage value at the end of the cable) to obtain the terminal voltage value, and then the power at the end of the cable is calculated through the current value. The power is integrated over time to obtain the energy at the end of the cable. The line loss energy is obtained by subtracting the energy at the end of the cable from the energy at the cable input.

[0050] Furthermore, the multi-function electric meter is installed on the charging column, and the two voltage wires are connected between the multi-function electric meter (i.e. the cable input end) and the charging gun head (i.e. the cable end).

[0051] Furthermore, the current on the same cable is the same, but the voltage at different points is different. The line loss energy can be calculated by collecting data at the input and output ends of the cable.

[0052] It is worth mentioning that the technical features such as charging piles and charging gun heads involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected according to the conventional methods in the field, and should not be regarded as the inventive point of the patent of this invention. The patent of this invention will not be further elaborated.

[0053] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multifunctional electric meter for calculating line loss through a four-wire system, characterized in that: It includes a central processing unit and an electric energy sampling unit, an electric energy calculation unit, a data storage unit, a voltage and current monitoring unit, an information input and output unit and a line loss calculation unit electrically connected to the central processing unit, wherein; The central processing unit is used to coordinate the work of various units; The electric energy sampling unit is used to process the collection function of basic data including voltage, current, active and reactive power; The electric energy calculation unit performs statistics and calculations based on the sampled basic data, thereby obtaining real-time electric quantity data; The data storage unit is used to store relevant data of the electric meter; The voltage and current monitoring unit is used to detect voltage and current values ​​in real time; The information input and output unit is used to manage functions including key input, liquid crystal display, pulse output, and power supply and disconnection; The line loss calculation unit measures terminal voltage and power, integrates time, and measures electric energy.

2. A multifunctional electric meter for calculating line loss through a four-wire system according to claim 1, characterized in that: For the line loss calculation unit, two voltage lines are added to the end of the cable, and the voltage value at the end of the cable is collected to calculate the line loss energy. The specific implementation is as follows: The power at the cable inlet is calculated by collecting the voltage at the cable inlet, and the energy passing through the cable inlet is obtained by integrating the power at the cable inlet with respect to time: P 线缆进端 =U 线缆进端 *AND; E 线缆进端 =∫P 线缆进端 (t)dt; The power at the end of the cable is calculated by collecting the voltage at the end of the cable, and the energy passing through the end of the cable is obtained by integrating the power at the end of the cable over time: P 线缆末端 =U 线缆末端 *AND; E 线缆末端 =∫P 线缆末端 (t)dt; After obtaining the energy at the cable entrance and the energy at the cable end, subtract them to get the cable loss energy: AND 损耗 =And 进端 -AND 末端 。 3. A multifunctional electric meter for calculating line loss through a four-wire system according to claim 2, characterized in that: Connect the current loop to the current sampling loop of the electric meter, connect the voltage at the cable input end to the voltage sampling loop of the electric meter, and obtain the energy at the cable input end through current sampling and voltage sampling; The voltage at the end of the cable is connected to the line loss compensation sampling loop to obtain the terminal voltage value, and then the power at the end of the cable is obtained through the current value. The power is integrated over time to obtain the energy at the end of the cable. The line loss energy is obtained by subtracting the energy at the end of the cable from the energy at the cable input.

4. The multifunctional electric meter for calculating line loss through a four-wire system according to claim 1, characterized in that: The multi-function meter is installed on the charging column, and the two voltage wires are connected between the multi-function meter and the charging gun head.

5. The multifunctional electric meter for calculating line loss through a four-wire system according to claim 3, characterized in that: The current on the same cable is the same, but the voltage at different points is different. The line loss energy is calculated by collecting data at the input and output ends of the cable.

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