Method for measuring electricity usage

Abstract

[Problem] To provide a method for accurately measuring, with an electricity meter, the electricity usage of a consumer for whom the watt-hour meter is installed. [Solution] In this method for measuring electricity usage: noise filters 3 are installed at or near an electricity meter 1, which is connected to electric wires 2 and connects a supplier who supplies electricity and a consumer who consumes the electricity, to eliminate or reduce noise that affects the manner in which the electricity meter 1 measures electricity usage; and if there are a plurality of electric wires 2, the noise filters 3 are installed collectively with respect to the plurality of electric wires. It is preferable to install the noise filters on both the supplier side and the consumer side across the electricity meter 1, and to install ferrite cores 3 on the electric wires 2.

Description

How to measure the amount of electricity used

[0001] The present invention relates to a method for accurately measuring the amount of power (amount of power used / amount of power consumed) used by a consumer in which a power meter (integrating power meter / watt meter) is installed, using the power meter.

[0002] There are various types of electricity meters, including mechanical meters, electronic meters, and smart meters, but all of them are connected to the electrical wires that connect suppliers such as electric power companies that supply electricity to consumers such as homes, offices, and factories that consume electricity.

[0003] The above-mentioned watt-hour meters have the problem of being unable to accurately measure the amount of electricity used due to the influence of noise caused by electromagnetic waves generated by the operation of various electrical appliances. In particular, since watt-hour meters are often installed outdoors, if an outdoor unit is installed nearby, there is a problem that operating a heating / cooling device will cause errors in the measurement by the watt-hour meter due to electromagnetic waves generated from the outdoor unit.

[0004] There are two types of noise: normal mode noise and common mode noise. Normal mode noise is noise that travels in opposite directions on the positive and negative sides of the power supply, and is a mode in which it returns to the power supply via the load. Common mode noise, on the other hand, is noise that travels in the same direction on the positive and negative sides of the power supply, and is a mode in which leaked noise returns to the power supply via the ground.

[0005] Therefore, in order to eliminate noise generated in the above-mentioned watthour meter, it has been proposed to use a current input device in the current input section of the watthour meter, which converts the input current into a voltage using a shunt resistor and outputs it, and which has a ferrite core provided in a fixed component of the path through which the input current flows before being converted into a voltage signal by the shunt resistor to eliminate common mode noise contained in the input current (see, for example, Patent Document 1 below).

[0006] It has also been proposed to reduce power consumption in homes and businesses by installing an electromagnetic wave absorber in a distribution board or panel board, which is made up of a soft magnetic material that absorbs electromagnetic waves, a laminated member that shields electromagnetic waves in a frequency band higher than the soft magnetic material, and an adhesive material (see, for example, Patent Document 2 below).

[0007] JP 2009-188320 A JP 2018-156981 A

[0008] However, according to the findings of the inventors of the present invention, it is not the occurrence of the above-mentioned noise that causes the increase in the amount of electricity used, but rather the occurrence of the above-mentioned noise that prevents the electricity meter from accurately measuring the amount of electricity used.

[0009] Therefore, an object of the present invention is to provide a method for accurately measuring the amount of power used by a watt-hour meter.

[0010] The present invention has been proposed to solve the above problems and has the following configuration. In the following, the numbers and symbols shown in the drawings attached to this application will be used to assist in understanding the configuration of the present invention.

[0011] The method for measuring the amount of electricity used according to claim 1 is a method for accurately measuring the amount of electricity used by a consumer in which an electricity meter (1) is installed, in the electricity meter (1), and is a method for measuring the amount of electricity used by installing a noise filter (3) in or near the electricity meter (1) connected to an electric wire (2) connecting an electricity supplier and a consumer who consumes the electricity, and removing or reducing noise that affects the measurement of the amount of electricity used by the electricity meter (1), characterized in that when there are multiple electric wires (2), the noise filter (3) is installed collectively for the multiple electric wires.

[0012] The method for measuring the amount of electricity used according to claim 2 is a method for accurately measuring the amount of electricity used by a consumer in which an electricity meter (1) is installed, in the electricity meter (1), and is a method for measuring the amount of electricity used by removing or reducing noise that affects the measurement of the amount of electricity used by the electricity meter (1) by installing a noise filter (3) on or near the electricity meter (1) connected to an electric wire (2) connecting a supplier that supplies electricity to a consumer that consumes the electricity, and is a method for measuring the amount of electricity used by installing a noise filter (3) on both the supplier side and the consumer side, with the electricity meter (1) as the boundary.

[0013] A method for measuring the amount of electric power used according to claim 3 is the method for measuring the amount of electric power used according to claim 1 or 2, in which a ferrite core (3) is used as the noise filter (3).

[0014] A method for measuring the amount of electric power used according to claim 4 is the method for measuring the amount of electric power used according to claim 3, in which a split type ferrite core (3) is used as the ferrite core (3).

[0015] The method for measuring the amount of power usage according to the present invention has the above-described configuration and therefore can achieve the following effects.

[0016] As described above, according to the findings of the inventors of the present invention, noise caused by electromagnetic waves and the like prevents a watthour meter from accurately measuring the amount of power used, but the method for measuring the amount of power used described in claim 1 can remove or reduce noise that affects the measurement of the amount of power used by the watthour meter (1) by installing a noise filter (3) on or near the watthour meter (1). Therefore, the method for measuring the amount of power used described in claim 1 can solve the problem that the present invention aims to solve, which is to provide a method for accurately measuring the amount of power used by a watthour meter.

[0017] Since noise that affects the electricity meter (1) often travels through the electric wire (2), by installing a noise filter (3) on the electric wire (2), as in the method for measuring the amount of electricity used described in claim 1, it is possible to effectively remove or reduce noise that affects the measurement of the amount of electricity used by the electricity meter (1).

[0018] Furthermore, according to the knowledge gained by the inventor of the present invention, when there are a plurality of electric wires (2), by installing noise filters (3) individually for the plurality of electric wires (2), as in the method for measuring the amount of electric power used as set forth in claim 1, it is possible to effectively remove or reduce normal mode noise in particular.

[0019] Furthermore, according to the knowledge gained by the inventor of the present invention, when there are a plurality of electric wires (2), by collectively installing a noise filter (3) for the plurality of electric wires (2), as in the method for measuring the amount of electric power used as described in claim 1, it is possible to effectively remove or reduce common mode noise in particular.

[0020] Here, even if a noise filter (3) is installed only on one side of the electricity meter (1), that is, the supplier side that supplies electricity or the consumer side that consumes the electricity, the noise generated in the electricity meter (1) can be removed or reduced to some extent, but it has been found that, as in the method for measuring the amount of electricity used described in claim 2, installing a noise filter (3) on both sides can more reliably remove or reduce the noise to a greater extent.

[0021] Generally, various known components such as coils, capacitors, and ferrite cores are used as noise filters (3). However, from the viewpoint of ease of attachment to electric wires, it is preferable to use a ferrite core, particularly a split type ferrite core, as in the method for measuring the amount of electric power used described in claim 3 or 4.

[0022] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.

[0023] A method for measuring the amount of power used according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0024] There are various types of watt-hour meters, such as mechanical watt-hour meters, electronic watt-hour meters, and smart meters, but in any case, they are connected to an electric wire (2) that connects suppliers such as electric power companies that supply electricity to consumers such as homes, offices, factories, etc., that consume electricity, as shown in Figures 1 and 2. The method for measuring the amount of electricity used according to the present invention can be implemented regardless of the type of watt-hour meter.

[0025] The method for measuring the amount of electricity used according to the present invention is a method for accurately measuring the amount of electricity used by a consumer in which a watt-hour meter (1) is installed, using the watt-hour meter. As shown in Figures 1 and 2, this method involves installing a noise filter (3) in or near the watt-hour meter (1) connected to an electric wire (2) connecting a supplier that supplies electricity to a consumer that consumes the electricity, and removing or reducing noise that affects the measurement of the amount of electricity used by the watt-hour meter (1).

[0026] According to the knowledge gained by the inventor of the present invention, the influence of noise caused by electromagnetic waves, etc., generated by the operation of various electrical appliances prevents the watt-hour meter (1) from accurately measuring the amount of electricity used. However, according to the method for measuring the amount of electricity used of the present invention, by installing a noise filter (3) on or near the watt-hour meter (1), it is possible to remove or reduce noise that affects the measurement of the amount of electricity used by the watt-hour meter (1).

[0027] Because noise affecting the watt-hour meter (1) often travels through the electric wires (2), installing a noise filter (3) on the electric wires (2), as shown in Figure 1, can effectively remove or reduce noise that affects the measurement of the amount of electricity used by the watt-hour meter (1). Furthermore, it is preferable to install the noise filter (3) as close to the watt-hour meter (1) as possible. This is because even if the noise filter (3) is installed far from the watt-hour meter (1), noise will penetrate the electric wires (2) between the noise filter (3) and the watt-hour meter (1) and be transmitted to the watt-hour meter (1), affecting it.

[0028] According to the findings of the inventors of the present invention, when there are multiple electric wires (2) as shown in Figure 1, it is possible to effectively remove or reduce normal mode noise by individually installing noise filters (3) for each of the multiple electric wires (2). Specifically, in the case of a single-phase three-wire power distribution system, which is currently mainstream in ordinary households, the electric wires (2) consist of two voltage wires (2a) on either side and one neutral wire (2b) sandwiched between them, and noise filters (3) are installed individually for each of the three electric wires. Of course, in the case of a single-phase two-wire power distribution system, the electric wires consist of one voltage wire and one neutral wire, and noise filters are installed individually for each of the two electric wires.

[0029] Furthermore, according to the findings of the inventors of the present invention, when there are multiple electric wires (2), as shown in Fig. 2, by collectively installing a noise filter (3) on the multiple electric wires (2), it is possible to effectively remove or reduce common mode noise in particular. Specifically, in a single-phase three-wire power distribution system, the electric wires (2) consist of two voltage wires (2a) and one neutral wire (2b) as described above, and a noise filter (3) is installed collectively on all three electric wires. Of course, in a single-phase two-wire power distribution system, the electric wires consist of one voltage wire and one neutral wire, and a noise filter is installed collectively on both electric wires.

[0030] 1 and 2, when there are multiple electric wires 2, it is possible to install noise filters 3 individually for the multiple electric wires 2, and also to install a collective noise filter 3 for the multiple electric wires 2. This is preferable because it makes it possible to effectively remove or reduce both normal mode noise and common mode noise.

[0031] According to the findings of the inventors of the present invention, it is possible to remove or reduce noise generated in the watt-hour meter (1) to a certain extent by installing a noise filter (3) only on one side of the watt-hour meter (1), which is the supplier side supplying electricity or the consumer side consuming that electricity, but it has been found that installing noise filters (3) on both sides, as shown in Figures 1 and 2, can more reliably remove or reduce noise generated in the watt-hour meter (1). Furthermore, installing more noise filters (3) generally more reliably removes or reduces noise generated in the watt-hour meter (1). In Figure 1, one noise filter (3) is installed on each of the three electric wires (2) on both the supplier side and the consumer side, separated by the watt-hour meter (1), and in Figure 2, four noise filters (3) are installed on each of the supplier side and the consumer side, separated by the watt-hour meter (1), but the number of noise filters is not particularly limited.

[0032] Generally, various known components such as coils, capacitors, and ferrite cores are used as noise filters. However, from the viewpoint of ease of attachment to an electric wire (2), it is preferable to use a ferrite core (3) as the noise filter (3) used in the method for measuring the amount of electric power used according to the present invention, as shown in FIGS. 1 and 2.

[0033] Ferrite cores are available in a variety of shapes, but using a ring-shaped ferrite core with an inner diameter large enough to fit tightly around the electric wire can suppress the generation of magnetic flux and more reliably eliminate or significantly reduce noise. However, ferrite cores of this type are difficult to install on the electric wire. Therefore, using a split ferrite core (3) as shown in Figure 3 makes it easy to install on the electric wire (2). Furthermore, if a gap occurs between the electric wire (2) and the ferrite core (3), the electric wire (2) can be wound around the ferrite core (3) to ensure close contact.

[0034] The inventor of the present invention compared the values ​​indicated by the electricity meter as the amount of electricity used in the same facility during the same season, and found that there was a significant difference in the measurement results of the amount of electricity used before and after implementing the method for measuring the amount of electricity used in the present invention, as shown in Table 1 below.

[0035]

[0036] 1 Watt-hour meter 2 Electric wire 2a Voltage wire 2b Neutral wire 3 Noise filter (ferrite core)

Claims

1. A method for accurately measuring the amount of electricity used by a consumer in which an electricity meter is installed, by installing a noise filter on or near the electricity meter connected to the electric wire connecting the electricity supplier and the consumer who consumes the electricity, and removing or reducing noise that affects the measurement of the amount of electricity used by the electricity meter, characterized in that when there are multiple electric wires, the noise filter is installed collectively on all of the multiple electric wires.

2. A method for accurately measuring the amount of electricity used by a consumer in which an electricity meter is installed, comprising installing a noise filter on or near the electricity meter connected to the electric wire connecting the electricity supplier and the consumer who consumes the electricity, and removing or reducing noise that affects the measurement of the amount of electricity used by the electricity meter, characterized in that a noise filter is installed on both the supplier side and the consumer side, separated by the electricity meter.

3. A method for measuring the amount of electric power consumption according to claim 1 or 2, characterized in that a ferrite core is used as the noise filter.

4. A method for measuring the amount of electric power used according to claim 3, characterized in that a split type ferrite core is used as the ferrite core.

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