JP2005227074A - Electronic alternating current watt-hour meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic watt-hour meter capable of displaying the output data of electronic watt-hour meters on a common display without hindrance, wherein for each distribution line in a power receiving business establishment, a single phase system, 3 phase 3 wire system, 3 phase 4 wire system, and different grounding systems are mixedly existing. <P>SOLUTION: The electronic watt-hour meter 1 comprises the single phase distribution wire way 3 and 3 phase distribution wire way 13 and respective electronic watt-hour meters 6, 16; the current detection devices 8, 18a, 18b, and the voltage detection means 7, 17; the computing means 9, 19 for computing the consumed electric power; the display device 25 composed of a computing part 28 for computing the consumed watt-hours, electric power charge etc., based on the data supplied by the electronic watt-hour meters 6, 16, the data memory part 29 and the display part 30 for displaying according to the specified display form; and the data transmitters 11, 21 and receiver 26 for wireless communication for the electronic watt-hour meter 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic AC watt-hour meter, and more particularly to an electronic watt-hour meter suitable for managing the total power consumption when a single-phase and a three-phase line received from a commercial AC power source coexist. It is.

  In order to pay a fee according to the amount of power consumed by power consumers (contracting subscribers) of commercial power, a watt-hour meter is installed in the power receiving unit, and the necessity of liberalization of power retailing and energy saving measures As a result, electronic watt-hour meters have come to be used in response to the fact that power charges are set to diversify according to power usage conditions.

  In other words, as is well known, when calculating the power consumption from the continuously detected current and voltage, the electronic watt-hour meter can calculate the charge integrated value even if the charge varies depending on the power usage time zone. Various calculations are possible. Furthermore, these data are calculated for each distribution line, regardless of single-phase power supply or three-phase power supply, and the instantaneous value and total value are calculated and displayed on a common display in various display formats. There is an excellent function that can provide various functions such as displaying the relationship with the power saving target in the current time zone, and warning when the target is deviated.

  By the way, in many factories and other establishments, there are usually cases where single-phase distribution lines commonly used for electric power and other low-power distribution, and three-phase distribution lines generally used for power, etc. are mixed. In addition, there are different wiring methods such as a three-wire type and a four-wire type for the three-phase distribution line as required, and there are cases where the grounding of each distribution line is different. In such a case, if data such as the amount of power for each line is output to a common circuit for display on a single display, an unexpected mutual interference circuit (hereinafter referred to as interference circuit) is formed through the output line, and the data is accurate. There is a risk that trouble will occur in the absence of electricity.

  In order to avoid the formation of such an interference circuit, as a general method conventionally performed, an insulating transformer is interposed in a signal line connecting between an electronic watt hour meter and a common display device, and each electronic type Electrical insulation is provided between the watt-hour meter and the display device. However, with this method, if the insulation specification of the insulation transformer is the insulation resistance value required when applied to an electronic watt-hour meter, the price increases, the size cannot be reduced, and the occurrence of errors cannot be prevented. It was not possible to overcome such problems.

  The object of the present invention has been made paying attention to the above-mentioned problems, and the distribution line is divided into single-phase, three-phase, three-phase three-wire, three-phase four-wire, and further on the ground. Regardless of the problem, power receiving establishments that have a distribution line mixed with these problems may interfere with the common display of the electric energy and other detection data detected by the electronic watt-hour meter attached to each distribution line. An object is to provide an electronic watt-hour meter that can be displayed without any problems.

  The electronic watt-hour meter of the present invention for achieving the above-described object is a line-type electronic watt-hour meter attached to each of distribution lines composed of at least one single-phase distribution line and a three-phase distribution line, and at least The electronic watt-hour meter for the line, comprising one display device, is a current and voltage detection means for detecting the power consumed in the distribution line, and the power consumption from the output signals of these detection means The display device includes a calculation unit that calculates power consumption, power charges, and the like based on data provided from the electronic watt-hour meter for the line, and a storage that stores the data. And a display unit that displays the data according to a predetermined display format, and the data is transmitted and received between the electronic watt-hour meter for the line and the display device by wireless communication. .

  The wireless communication means is not particularly limited, and preferable means include a means using weak radio waves that can radiate radio waves without permission and a means using infrared rays. Further, depending on the situation, optical communication means other than infrared rays, optical fiber means, and the like can be used.

  The line electronic watt-hour meter can be provided with a writable and rewritable memory, and data such as the electric energy stored in the memory can be transmitted to the display device at predetermined time intervals. .

  A storage unit may be provided in the display device, basic data may be stored in the storage unit, and the data may be processed and displayed into power usage status and other necessary information. Specifically, the amount of power used or electricity rate, the comparison between energy saving target and performance, etc. are displayed numerically or by graph, by hour, hour, month, year, distribution line, etc. This information is useful for understanding the actual usage of electricity. In addition, information that needs to be dealt with urgently, for example, an alarm when the amount of power used rises or falls abnormally can be displayed in characters, colors, sounds, and the like.

  Since the electronic watt hour meter of the present invention performs signal transmission between the electronic watt hour meter attached to each distribution line and the display device by means of extremely high electrical insulation such as wireless communication and optical communication. The mutual interference circuit described above is formed between different distribution lines through the signal line between the line electronic watt-hour meter and the display device, and it is possible to prevent the accurate data from being transmitted.

  Hereinafter, an electronic watt-hour meter according to the present invention will be described in detail with reference to the accompanying drawings.

  An electronic watt-hour meter 1 according to the present embodiment shown in FIG. 1 is attached to a business establishment (electric power consumer) 2 that is supplied from a single-phase AC power supply E1 and a three-phase AC power supply E2 by a commercial power supply.

  A distribution electronic power meter 6 is attached to a distribution line 5 connecting the lead-in line 3 of the single-layer AC power supply E1 and the load 4, and a distribution line 15 connecting the lead-in line 13 of the three-phase AC power supply E2 and the load 14 is attached. Is attached with a line-type electronic watt-hour meter 16. It is assumed that the loads 4 and 14 shown in FIG. 1 include any one load or a plurality of loads connected in parallel.

  First, the single-layer AC power supply E1 will be described. In FIG. 1, the voltage detector 7 and the current detector 8 attached to the electronic watt-hour meter 6 for a line are both current transformers that have been conventionally used, and will not be described. The voltage signal v detected by the voltage detector 7 and the current signal i detected by the current detector 8 are sent to a calculation unit 9 composed of a microcomputer (not shown), where the vector product is then integrated by time. So that the obtained electric energy is stored in a nonvolatile memory (not shown) made of EEPROM, and is output to the transmitter 10 at a predetermined time, for example, every second, so that new data is stored. did.

  The transmitter 10 attaches an identification symbol indicating the distribution line 5 to the data sent from the calculation unit 9 and transmits the data from the antenna 11 by weak radio waves. Regarding the three-phase power supply E2, the circuit elements common to the description of the single-phase power supply E1 are given the reference numerals added to the single-phase power supply E1 side, and the functions and operations are the same. Description is omitted. The current detectors 18a and 18b are both current detection current transformers.

  The weak radio waves transmitted from the antennas 11 and 21 are received by the antenna 27 of the receiver 26 attached to the display device 25, and are separated into data of the line watt-hour meters 9 and 19, respectively. The data can be sent to the storage unit 29 such as an EEPROM, and at the same time, arithmetic processing specified by an operation button (not shown), for example, monitoring for alarm output can be performed. If dedicated software is installed, a personal computer can be used for the display device.

  Further, examples of the display by the arithmetic processing designated by the operation button can include, for example, the comparison between the power usage record of the previous day and the current use record, the achievement rate with respect to the energy saving target value, and the like.

  As described above, the electronic watt-hour meter according to the present embodiment is a wireless transmission means (transmitter 10 and transmitter 10 and 16) that can electrically completely insulate between the line watt-hour meters 6 and 16 and the display device 25. 20 and the receiver 26), even if the power consumption detection signals of the distribution lines 5 and 15 formed by the different power sources E1 and E2 are given to the same electric circuit, the grounding of the distribution line 5 and the distribution line 15 respectively. Thus, an interference circuit is formed between the signal output lines of the line electronic watt-hour meters 6 and 16 and the distribution lines 5 and 15, and the possibility of causing an abnormality in the output data can be reliably eliminated.

It is a principal part block diagram for demonstrating the outline | summary of the electronic watt-hour meter by embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic watt-hour meter, 5 ... Distribution line, 9 ... Line electronic watt-hour meter, 10 ... Transmitter, 15 ... Distribution line, 19 ... Electronic watt-hour meter for line, 21 ... Transmitter, 25 ... Display device, 26 ... receiver

Claims (4)

It consists of a line electronic watt-hour meter attached to each distribution line consisting of at least one single-phase distribution line and a three-phase distribution line, and at least one display device. Current and voltage detection means for detecting the power consumed in the distribution line, and calculation means for calculating the power consumption from the output signals of these detection means, the display device is an electronic type for the line A calculation unit that calculates the amount of power consumption based on data provided from a watt hour meter, a power charge, a storage unit that stores the data, and a display unit that displays the data according to a predetermined display format, An electronic watt-hour meter configured to transmit and receive the data by wireless communication between the line electronic watt-hour meter and a display device. The electronic watt-hour meter according to claim 1, wherein the wireless communication means is one selected from means using weak radio waves and means using infrared rays. 2. The line electronic watt-hour meter is provided with a rewritable and rewritable memory, and data such as the electric energy stored in the memory is transmitted toward the display device at predetermined time intervals. Or the electronic watt-hour meter of 2. The storage unit is provided in the display device, basic data is stored in the storage unit, and the data can be displayed after being processed into usage information or other necessary information. Electronic watt-hour meter as described in 2.

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