JP2004226094A - Electronic type watt-hour meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic type watt-hour meter capable of improving reliability of metering by discovering a fault or an abnormality immediately when it occurs. <P>SOLUTION: This meter is equipped with a plurality of individual electric energy calculation parts 11, 12 for calculating individual electric energy by multiplying the line voltage between a reference line and the pertinent line in three wires respectively and the current flowing in the pertinent line together, a plurality of individual electric energy storage part 15, 16 provided corresponding to the plurality of individual electric energy calculation parts 11, 12, for storing respectively the individual electric energy from each individual electric energy calculation part, an overall electric energy storage part 14 for storing overall electric energy acquired by synthesizing a plurality of individual electric energies from the plurality of individual electric energy calculation parts 11, 12, and a control part 13 for outputting the overall electric energy stored in the overall electric energy storage part 14 and determining existence of the abnormality based on the plurality of individual electric energies stored in a plurality of individual electric energy storage part 15, 16. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic watt-hour meter, and more particularly to a technique for improving the reliability of measurement.
[0002]
[Prior art]
Conventionally, watt-hour meters have been used to measure power. Conventionally, inductive watt-hour meters have been used as such watt-hour meters. In recent years, electronic watt-hours that can be mounted in a small space and have no mechanical movable parts, so there is no restriction on the mounting direction. Meter is becoming popular.
[0003]
FIG. 6 is a block diagram showing a configuration of a single-phase three-wire low-voltage electronic watt-hour meter, which is one of such electronic watt-hour meters. The electronic wattmeter includes a power supply terminal 2, a load terminal 3, a first current detector (CT1) 4, a first voltage detector (VT1) 5, a third current detector (CT3) 6, and a third It comprises a voltage detector (VT3) 7, a metering / controller 8a, a display 9 and a communication unit 10.
[0004]
The power supply side terminal 2 includes a terminal 2S to which the neutral phase (N phase) of the power supply is connected, a terminal 1S to which the first phase is connected, and a terminal 3S to which the third phase is connected. In the case of the single-phase three-wire system, the power of the first phase and the power of the third phase do not have different phases (they are single-phase), but in this specification, for convenience, the “first phase” is used. And "the third phase". Similarly, the load-side terminal 3 includes a terminal 2L connected to the neutral phase (N-phase) of the load, a terminal 1L connected to the first phase, and a terminal 3L connected to the third phase.
[0005]
The first current detector 4 is provided in the first phase current path, detects a current flowing from the terminal 1S to the terminal 1L, and sends the detected current I1 to the metering / control unit 8a. The first voltage detector 5 detects a voltage between the N-phase and the first phase, and sends the detected voltage V1 to the metering / controller 8a.
[0006]
The third current detection unit 6 is provided in the third phase current path, detects a current flowing from the terminal 3S to the terminal 3L, and sends the detected current I3 to the measurement / control unit 8a. The third voltage detection unit 7 detects a voltage between the N phase and the third phase, and sends the detected voltage V3 to the measurement / control unit 8a.
[0007]
The measuring / control unit 8 includes a current I1 from the first current detection unit 4, a voltage V1 from the first voltage detection unit 5, a current I3 from the third current detection unit 6, and a voltage V3 from the third voltage detection unit 7. The amount of power is measured based on. Details of the weighing / control unit 8a will be described later. The display unit 9 displays the amount of power measured by the measurement / control unit 8a and other information. The communication unit 10 is used to perform various settings for the remote meter reading and the metering / control unit 8a.
[0008]
FIG. 7 is a block diagram showing a detailed configuration of the weighing / control unit 8a. The measurement and control unit 8a includes a first power multiplication unit 71, a third power multiplication unit 72, a synthesis-pulse conversion unit 73, and a pulse processing, measurement and control unit 13.
[0009]
The first power multiplying unit 71 calculates the power of the first phase by multiplying the current I1 detected by the first current detecting unit 4 and the voltage V1 detected by the first voltage detecting unit 5, and calculates the power of the first phase. The signal is sent to the pulse converter 73. The third power multiplying unit 72 calculates the power of the third phase by multiplying the current I3 detected by the third current detecting unit 6 and the voltage V3 detected by the third voltage detecting unit 7 to calculate the power of the third phase. The signal is sent to the pulse converter 73.
[0010]
The combining-pulse converting unit 73 combines the power calculated by the first power multiplying unit 71 and the power calculated by the third power multiplying unit 72 and converts the power into a pulse having a frequency proportional to the combined power. I do. The pulse obtained by the synthesis-pulse conversion unit 73 is sent to the pulse processing / metering / control unit 13 as a pulse signal representing an electric energy pulse.
[0011]
The pulse processing / metering / control unit 13 is constituted by, for example, a microcomputer, and accumulatively adds (accumulates) the power amount pulse included in the pulse signal transmitted from the synthesis-pulse conversion unit 73 to the total power amount storage unit 14. ). Then, the pulse processing / metering / control unit 13 sends the total power amount stored in the total power amount storage unit 14 to the display unit 9. Thereby, the total electric energy is displayed on the display unit 9. In addition, the pulse processing / metering / control unit 13 sends the total power stored in the total power storage unit 14 to the communication unit 10. Thereby, the communication unit 10 transmits the total electric energy to the electric power company, and the electric power company performs billing or the like based on the total electric energy.
[0012]
Note that, for example, Patent Literature 1 is a conventional technique related to a conventional electronic watt-hour meter.
[0013]
[Patent Document 1]
Patent No. 3112611 (Pages 3-6, Fig. 5)
[0014]
[Problems to be solved by the invention]
However, in the above-mentioned conventional electronic watt-hour meter, if one of the first power multiplying unit 71 and the third power multiplying unit 72 fails, correct metering cannot be performed. Since it fluctuates depending on the state, the discovery of a failure may be delayed. Even if the watt hour meter is operating within the rated power, the power of the first phase and the third phase may greatly exceed the capacity of one phase if the power of the phase is greatly disturbed. Discovery may be delayed.
[0015]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electronic device capable of immediately detecting a failure or abnormality and improving the reliability of measurement when a failure or abnormality occurs. An object of the present invention is to provide a watt-hour meter.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the electronic watt-hour meter according to the present invention is arranged such that the number of lines from the power supply side is one smaller than the number of lines from the power supply side, and each of the plurality of lines is one of the plurality of lines. A plurality of individual power amount calculation units for calculating an individual power amount by multiplying a line voltage between the reference line and the line by a current flowing through the line, and provided in correspondence with the plurality of individual power amount calculation units. A plurality of individual power amount storage units each storing the individual power amount from the individual power amount calculation unit and a plurality of individual power amounts from the plurality of individual power amount calculation units. A total power amount storage unit that stores the total power amount, and a plurality of external power amounts that are stored in the total power amount storage unit and output to the external power amount storage unit. A control unit that determines whether there is an abnormality based on the individual electric energy. It is characterized in.
[0017]
According to the first aspect of the present invention, since a plurality of individual power amounts are also stored in addition to the total power amount, by referring to the plurality of individual power amounts, the presence or absence of a failure or abnormality is determined. Can be discovered quickly.
[0018]
In the invention according to claim 2, the control unit includes an abnormality determination information storage unit, and at least one of the plurality of individual power amounts stored in the plurality of individual power amount storage units has a value outside a predetermined range. In this case, it is determined that an abnormality has occurred, and the fact is stored in the abnormality determination information storage unit.
[0019]
According to the second aspect of the present invention, by referring to the abnormality determination information storage unit, it is possible to know at any time whether or not there is a failure or abnormality, so that it is possible to find these immediately.
[0020]
Further, in the invention according to claim 3, each of the plurality of individual power amount calculation units converts the individual power amount into a pulse having a frequency and a sign corresponding to the individual power amount, and stores the plurality of individual power amount storages. The unit accumulates and stores the number of pulses transmitted from the plurality of individual power amount calculation units, and stores the total number of pulses transmitted from the plurality of individual power amount calculation units. , And accumulate and store in consideration of the sign.
[0021]
Further, in the invention according to claim 4, the plurality of individual power amount calculation units are formed integrally with the control unit.
[0022]
According to the fourth aspect of the present invention, it is easy to integrate the plurality of individual power amount calculation units and the control unit into one chip, and the electronic watt-hour meter can be configured small and inexpensively.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an electronic watt-hour meter according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0024]
(First Embodiment)
The electronic watt-hour meter according to the first embodiment of the present invention is different from the conventional electronic watt-hour meter shown in FIG. different. Therefore, the entire description of the electronic watt-hour meter will be omitted, and only the configuration and operation of the metering / control unit 8 will be described.
[0025]
FIG. 1 is a block diagram showing the configuration of the metering / control unit 8 of the electronic watt-hour meter according to the first embodiment of the present invention. The metering / control unit 8 includes a first power-pulse converter 11, a third power-pulse converter 12, and a pulse processing / metering / control unit 13.
[0026]
The first power-to-pulse converter 11 calculates the first phase power by multiplying the current I1 from the first current detector 4 by the voltage V1 from the first voltage detector 5 and further calculates this power. The converted power is converted into a pulse having a frequency proportional to the power and having a positive (+) or negative (-) sign. The pulse obtained by the first power-to-pulse converter 11 is sent to the pulse processing / metering / controller 13 as a pulse signal representing an electric energy pulse.
[0027]
The third power-to-pulse converter 12 calculates the power of the third phase by multiplying the current I3 from the third current detector 6 by the voltage V3 from the third voltage detector 7, and further calculates this power. The converted power is converted into a pulse having a frequency proportional to the power and having a positive (+) or negative (-) sign. The pulse obtained by the third power-to-pulse converter 12 is sent to the pulse processing / metering / controller 13 as a pulse signal representing an electric energy pulse.
[0028]
The pulse processing / metering / control unit 13 is composed of, for example, a microcomputer, and includes a total power storage unit 14, a first phase power storage unit 15, a third phase power storage unit 16, and an abnormality determination information storage unit 17. It has. The pulse processing / measurement / control unit 13 stores the power amount pulse from the first power-to-pulse conversion unit 11 and the power amount pulse from the third power-to-pulse conversion unit 12 in consideration of the sign and stores the total power amount. The cumulative addition (integration) is performed in the unit 14.
[0029]
In addition, the pulse processing / metering / control unit 13 accumulates (accumulates) the power amount pulse from the first power-to-pulse conversion unit 11 in the first phase power amount storage unit 15, and outputs the third power-to-pulse conversion unit. The electric energy pulse from 12 is accumulated and added to the third phase electric energy storage unit 16.
[0030]
In addition, the pulse processing / metering / control unit 13 determines that the value stored in the first phase power amount storage unit 15 and the value stored in the third phase power amount storage unit 16 are “0” or “ It is determined that an abnormality has occurred when the value exceeds the predetermined value, that is, when the value falls outside the predetermined range, and abnormality determination information indicating that fact is stored in the abnormality determination information storage unit 17.
[0031]
Further, the pulse processing / metering / control unit 13 stores the contents stored in the total power storage unit 14, the first phase power storage unit 15, the third phase power storage unit 16, and the abnormality determination information storage unit 17. Send it to the display unit 9. Thus, the total power, the first phase power, the third phase power, and the abnormality determination information are displayed on the display unit 9. Further, the pulse processing / metering / control unit 13 stores the contents stored in the total power storage unit 14, the first phase power storage unit 15, the third phase power storage unit 16, and the abnormality determination information storage unit 17. Send to communication unit 10. Thereby, the communication unit 10 transmits the total power, the first phase power, the third phase power, and the abnormality determination information to the power company.
[0032]
As described above, according to the electronic watt-hour meter according to the first embodiment of the present invention, not only the total electric energy obtained by synthesizing and integrating the first-phase electric energy and the third-phase electric energy, but also The one-phase power amount, the third-phase power amount, and the abnormality determination information are stored, and can be displayed on the display unit 9 or transmitted to the power company via the communication unit 10 as appropriate. Therefore, when a failure or abnormality occurs, the customer or the electric power company can quickly find them and improve the reliability of measurement.
[0033]
When the total amount of power is obtained by combining the power amount pulse from the first power-to-pulse converter 11 and the power amount pulse from the second power-to-pulse converter 12, even if the value of the cumulative addition is positive (+), When applied to a power factor state or a three-phase three-wire system described later (for example, due to a reverse connection), one of them may be negative (-). In consideration of this, a process of cumulatively adding the electric energy pulse is performed.
[0034]
(Second embodiment)
The second embodiment of the present invention is a three-phase three-wire electronic watt-hour meter with a transformer using a transformer for an instrument.
[0035]
As shown in FIG. 2, this electronic watt-hour meter is provided with a voltage terminal 33 and a current terminal 34 for inputting the voltage transformed by the instrument transformer 32 and the transformed current, respectively. ing. The instrument transformer 32 includes a first-phase voltage, a second-phase voltage, and a third-phase voltage generated by transforming the power supply voltage, and a first-phase current generated by transforming the power supply current. And a current of the third phase.
[0036]
The voltage terminal 33 is a terminal P1 to which a first-phase transformed voltage is supplied from the instrument transformer 32, a terminal P2 to which a second-phase transformed voltage is supplied, and a third-phase transformed voltage. Is supplied from the terminal P3. The first voltage detection unit (VT1) 5 detects a voltage between the second phase and the first phase, and sends the detected voltage V1 to the measurement / control unit 8. The third voltage detection unit (VT3) 7 detects a voltage between the second phase and the third phase, and sends the detected voltage V3 to the measurement / control unit 8.
[0037]
The current terminal 34 is a terminal 1S to which the first-phase transformed current from the instrument transformer 32 is input, a terminal 1L to which the first-phase transformed current is output, and an instrument transformer. The terminal 3S is provided with a terminal 3S to which a third-phase transformed current from the terminal 32 is inputted and a terminal 3L to which a third-phase transformed current is outputted.
[0038]
The first current detector (CT1) 4 is provided in the first phase current path, detects a current flowing between the terminal 1S and the terminal 1L, and sends the detected current I1 to the metering / control unit 8. . The third current detector (CT3) 6 is provided in the current path of the third phase, detects a current flowing between the terminal 3S and the terminal 3L, and sends the detected current I3 to the metering / controller 8. .
[0039]
Measurement / control in which the current I1 from the first current detector 4, the voltage V1 from the first voltage detector 5, the current I3 from the third current detector 6, and the voltage V3 from the third voltage detector 7 are input. The configuration and operation of the unit 8 are the same as those described for the electronic watt-hour meter according to the above-described first embodiment.
[0040]
As described above, according to the electronic watt-hour meter according to the second embodiment, the power from the power source is stepped down and reduced by the instrument transformer 32, and the first voltage detection unit 5 and the third voltage detection unit 7 , Is supplied to the first current detector 4 and the third current detector 6, so that it can be used as a high-voltage electronic wattmeter.
[0041]
(Third embodiment)
The third embodiment of the present invention is a three-phase four-wire electronic watt-hour meter with a transformer using an instrument transformer.
[0042]
As shown in FIG. 3, the electronic wattmeter separates a voltage terminal 43 and a current terminal 44 for inputting the voltage transformed by the instrument transformer 42 and the transformed current, respectively. Have. In addition, in addition to the configurations of the first and second embodiments described above, a second current detector (CT2) 45 and a second voltage detector (VT2) 46 are provided. Further, the metering / control unit 47 includes a second power-pulse conversion unit 48 for processing the current I2 and the voltage V2 from the second current detection unit 45 and the second voltage detection unit 46. The details will be described later.
[0043]
The instrument transformer 42 is generated by transforming the first-phase voltage, the second-phase voltage, the third-phase voltage, the neutral-phase voltage, and the power supply current generated by transforming the power supply voltage. The first phase current, the second phase current, and the third phase current are output.
[0044]
The voltage terminal 43 is a terminal P1 to which a first-phase transformed voltage is supplied from the instrument transformer 42, a terminal P2 to which a second-phase transformed voltage is supplied, and a third-phase transformed voltage. And a terminal P0 to which a neutral phase voltage is supplied. The first voltage detection unit (VT1) 5 detects a voltage between the neutral phase and the first phase, and sends the detected voltage V1 to the measurement / control unit 47. The second voltage detection section (VT2) 46 detects a voltage between the neutral phase and the second phase, and sends the detected voltage V2 to the measurement / control section 47. The third voltage detection unit (VT3) 7 detects a voltage between the neutral phase and the third phase, and sends the detected voltage V3 to the measurement / control unit 47.
[0045]
The current terminal 44 includes a terminal 1S to which the first-phase transformed current from the instrument transformer 42 is input, a terminal 1L to which the first-phase transformed current is output, and an instrument transformer. The terminal 2S to which the second-phase transformed current is input from the terminal 42, the terminal 2L to which the second-phase transformed current is output, and the third-phase transformed current from the instrument transformer 32. It comprises a terminal 3S to which a current is input and a terminal 3L to which a third-phase transformed current is output.
[0046]
The first current detector (CT1) 4 is provided in the first phase current path, detects a current flowing between the terminal 1S and the terminal 1L, and sends the detected current I1 to the metering / control unit 47. . The second current detector (CT2) 45 is provided in the second-phase current path, detects a current flowing between the terminal 2S and the terminal 2L, and sends the detected current I2 to the metering / control unit 47. . The third current detector (CT3) 6 is provided in the third phase current path, detects a current flowing between the terminal 3S and the terminal 3L, and sends the detected current I3 to the metering / control unit 47. .
[0047]
FIG. 4 is a block diagram showing a detailed configuration of the metering / control unit 47 of the electronic watt-hour meter according to the third embodiment of the present invention. The metering / control unit 47 includes a second power-to-pulse converter 48 added to the metering / control unit 8 of the electronic watt-hour meter according to the first and second embodiments of the present invention, and performs pulse processing. It is composed of a pulse processing / metering / control unit 13A in which a second-phase power amount storage unit 49 is added to the metering / control unit 13.
[0048]
The second power-to-pulse converter 48 calculates the second phase power by multiplying the current I2 from the second current detector 45 by the voltage V2 from the second voltage detector 46, and further calculates this power. The converted power is converted into a pulse having a frequency proportional to the power and having a positive (+) or negative (-) sign. The pulse obtained by the second power-to-pulse converter 48 is sent to the pulse processing / metering / control unit 13 as a signal representing a power amount pulse.
[0049]
The pulse processing / metering / control unit 13A is constituted by, for example, a microcomputer, and includes a total power storage unit 14, a first phase power storage unit 15, a second phase power storage unit 49, and a third phase power storage. It has a unit 16 and an abnormality determination information storage unit 17. The pulse processing / metering / control unit 13 </ b> A includes a power amount pulse from the first power-to-pulse converter 11, a power amount pulse from the second power-to-pulse converter 48, and a power amount from the third power-to-pulse converter 12. The pulses are cumulatively added (integrated) to the total power storage unit 14 in consideration of the sign.
[0050]
Further, the pulse processing / metering / control unit 13A accumulates (accumulates) the power amount pulse from the first power-to-pulse conversion unit 11 in the first phase power amount storage unit 15 and performs the second power-to-pulse conversion unit 48. Are cumulatively added (integrated) to the second-phase power storage unit 49, and the power pulses from the third power-to-pulse converter 12 are cumulatively added (integrated) to the third-phase power storage unit 16. I do.
[0051]
Further, the pulse processing / measurement / control unit 13 </ b> A stores the value stored in the first phase power storage unit 15, the value stored in the second phase power storage 49, or the third phase power storage unit. When the value stored in 16 is “0” or “a value equal to or greater than a preset value”, it is determined that an abnormality has occurred, and abnormality determination information indicating that fact is stored in the abnormality determination information storage unit 17. I do.
[0052]
Further, the pulse processing / metering / control unit 13A includes a total power storage unit 14, a first phase power storage unit 15, a second phase power storage unit 49, a third phase power storage unit 16, and an abnormality determination information storage. The contents stored in the section 17 are sent to the display section 9. Thus, the total power, the first phase power, the second phase power, the third phase power, and the abnormality determination information are displayed on the display unit 9.
[0053]
The pulse processing / metering / control unit 13A includes a total power storage unit 14, a first phase power storage unit 15, a second phase power storage unit 49, a third phase power storage unit 16, and an abnormality determination information storage. The contents stored in the unit 17 are sent to the communication unit 10. As a result, the communication unit 10 transmits the total power, the first phase power, the second phase power, the third phase power, and the abnormality determination information to the power company.
[0054]
As described above, according to the electronic watt-hour meter according to the third embodiment of the present invention, when a failure or abnormality occurs in each phase of the three-phase AC, the customer or the power company Can be found quickly, and the reliability of weighing can be improved.
[0055]
(Fourth embodiment)
The electronic watt-hour meter according to the fourth embodiment of the present invention includes a first power-pulse converter 11 and a first power-pulse converter 11 in the metering / control unit 8 of the electronic watt-hour meters according to the first and second embodiments. The function of the third power-to-pulse converter 12 is realized by software processing in the power multiplier / metering / control unit 61.
[0056]
FIG. 5 is a block diagram showing a detailed configuration of the metering / control unit 8A of the electronic watt-hour meter according to the fourth embodiment of the present invention. The weighing / controlling unit 8A includes a power multiplying / weighing / controlling unit 61.
[0057]
The power multiplying / measuring / controlling unit 61 is composed of, for example, a microcomputer, and includes a current I1 from the first current detecting unit 4, a voltage V1 from the first voltage detecting unit 5, and a current from the third current detecting unit 6. I3 and the voltage V3 from the third voltage detector 7 are directly supplied. The current I1, the voltage V1, the current I3, and the voltage V3 are digitally converted by an A / D converter (not shown) provided in the power multiplying / measuring / controlling unit 61, and then converted into first and second signals. Functions equivalent to those of the first power-to-pulse converter 11 and the third power-to-pulse converter 12 in the second embodiment, that is, multiplication and pulse conversion are performed by software processing.
[0058]
As described above, according to the electronic watt-hour meter according to the fourth embodiment of the present invention, the first power-pulse converter 11 and the third power-pulse converter in the first and second embodiments are used. Since the functions equivalent to 12, that is, multiplication and pulse conversion are performed by software processing, the number of components is reduced, which is suitable for one chip.
[0059]
In addition, it is possible to detect the lack of the voltages V1 and V3 or the currents I1 and I3, and when the power amount becomes “0” or “a numerical value equal to or more than a preset value”, of course, “ It is also possible to determine a “DC component value that is equal to or greater than the calculated value”, and this can be used as abnormality determination information.
[0060]
【The invention's effect】
As described above, according to the present invention, when a failure or abnormality occurs, it is possible to provide an electronic watt-hour meter that can immediately detect the failure and improve the reliability of measurement.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a metering / control unit of an electronic watt-hour meter according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of an electronic watt-hour meter according to a second embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of an electronic watt-hour meter according to a third embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a metering / control unit of an electronic watt-hour meter according to a third embodiment of the present invention.
FIG. 5 is a block diagram showing a configuration of a metering / control unit of an electronic watt-hour meter according to a fourth embodiment of the present invention.
FIG. 6 is a block diagram showing the configurations of an electronic watt-hour meter according to the first embodiment of the present invention and a conventional electronic watt-hour meter.
FIG. 7 is a block diagram showing a configuration of a metering / control unit of a conventional electronic watt-hour meter.
[Explanation of symbols]
2 power supply side terminal 3 load side terminal 4 first current detector 5 first voltage detector 6 third current detector 7 third voltage detector 8 metering / control unit 9 display unit 10 communication unit 11 first power-pulse conversion Unit 12 third power-pulse conversion unit 13 pulse processing / metering / control unit 14 total power storage unit 15 first phase power storage unit 16 second phase power storage unit 17 abnormality determination information storage unit 32 instrument transformer 33 Voltage Terminal 34 Current Terminal 42 Instrument Transformer 43 Voltage Terminal 44 Current Terminal 45 Second Phase Current Detector 46 Second Phase Voltage Detector 47 Metering / Control Unit 48 Second Power-Pulse Converter 49 Second Phase Power Amount Storage unit 61 Power multiplication / metering / control unit

Claims (4)

A number smaller than the number of the plurality of lines from the power supply by one is provided, and each multiplies the voltage between the reference line and the line among the plurality of lines by the current flowing through the line to obtain the individual power amount. A plurality of individual power amount calculation units to calculate;
A plurality of individual power amount storage units provided corresponding to the plurality of individual power amount calculation units, each storing the individual power amount from the individual power amount calculation unit;
A total power storage unit that stores a total power obtained by combining the plurality of individual powers from the plurality of individual power calculation units;
A control unit that outputs the total power amount stored in the total power amount storage unit to the outside, and determines whether there is an abnormality based on the plurality of individual power amounts stored in the plurality of individual power amount storage units When,
An electronic watt-hour meter comprising: The control unit includes an abnormality determination information storage unit,
It is determined that an abnormality has occurred when at least one of the plurality of individual power amounts stored in the plurality of individual power amount storage units has a value out of a predetermined range, and the abnormality determination information storage is performed to that effect. The electronic watt-hour meter according to claim 1, wherein the electronic watt-hour is stored in a unit. Each of the plurality of individual power amount calculation unit converts the individual power amount into a pulse having a frequency and a sign corresponding to the individual power amount,
The plurality of individual power amount storage units accumulate and store the number of pulses transmitted from the plurality of individual power amount calculation units,
2. The electronic power amount according to claim 1, wherein the total power amount storage unit accumulates and stores in consideration of a plurality of pulses and codes sent from the plurality of individual power amount calculation units. Total. 4. The electronic watt-hour meter according to claim 1, wherein the plurality of individual watt-hour calculation units are formed integrally with the control unit. 5.

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