JP2003222645A - Multicircuit power measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multicircuit power measuring device capable of collectively gathering data which eliminates wasteful devices, assures high measurement precision, and eliminates the need for installing a power source circuit to each of a separate measuring device. <P>SOLUTION: The multicircuit power measuring device measures power consumption and electric energy of a plurality of load circuits 5a-5c connected to a power distribution system. It comprises a main device 1 which inputs a power source voltage from a power path 7 and supplies a voltage signal corresponding to the power source voltage, CTs 3a-3c which detect the current flowing the load circuit and supply a current signal corresponding to the current, and separate measuring devices 2a-2c which are, provided to the load circuits 5a-5c, supplied with a voltage signal from the main device 1 and also supplied with a current signal from the CTs 3a-3c. The separate measuring devices 2a-2c comprise power calculation circuits 21a-21c which calculate power consumption of the load circuit based on the current signal flowing the load circuit detected by the CTs 3a-3c and the voltage signal supplied from the main device 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-circuit power measuring device for measuring power for energy saving in factories, buildings and the like.

[0002]

2. Description of the Related Art Interest in energy saving has been increasing due to the tightening of regulations on energy consumption in factories and buildings. To save energy, power equipment,
In addition to replacing air-conditioners and lighting equipment with energy-efficient ones, understanding where and how energy is currently used is an important point for effective improvement.

Conventionally, in power energy, demand monitoring at the power receiving end from a power company has been the main, but from the above circumstances, it has become necessary to measure the power consumption of the load of each low voltage circuit.

For such an application, a multi-circuit power measuring device as shown in FIG. 7 has recently come into use. The multi-circuit power measuring apparatus 101 shown in FIG. 7 has power consumption of load circuits 105a to 105e connected to an electric circuit 107, which is a power distribution system, via breakers 111a to 111e.
The amount of electric power is measured, and the load circuits 105a to 10a
The power calculation circuits 103a to 103e are provided corresponding to 5e.

The power calculation circuits 103a to 103e have loads detected by a predetermined voltage and a current transformer (hereinafter abbreviated as CT) 113a to 113e in which the power supply voltage from the electric circuit 107 is converted by the voltage conversion circuit 104. Circuit 10
5a to 105e and the load circuit 10 based on the current.
The power of 5a to 105e is calculated. That is, for example, in the device 101 capable of measuring 5 single-phase circuits, the device 101 includes 5 single-phase power arithmetic circuits.

[0006]

However, the apparatus shown in FIG. 7 has the following problems. That is,
When the load circuit to be measured is smaller than the power calculation circuit, waste occurs. For example, even if the measuring device includes a power calculation circuit for five circuits, if the load circuit to be measured has only two circuits, three circuits are wasted.

Further, the CT used as the electric power measuring sensor has considerable variations among individual products. In the case of a watt-hour meter or the like used for electricity rate transactions, the CT has a built-in meter, so that variations are corrected by adjustment.

However, in the multi-circuit power measuring device as shown in FIG. 7, since the connected CT is unspecified,
It cannot be adjusted in advance. Therefore, high measurement accuracy cannot be guaranteed.

The load circuit to be measured has 50 A
There is also a circuit of 250A and a circuit of 250A, and the CT having a rating according to the measurement target is used. Therefore, in the case of the device shown in FIG. 7, it is necessary to perform an operation of setting which rating of CT is connected to which connection terminal.

Therefore, instead of the device shown in FIG. 7, a small power measuring device as shown in FIG. 8 can be considered. The device shown in FIG. 8 is provided with small power measuring devices 121a to 121e corresponding to the load circuits 105a to 105e,
Each of the small power measuring devices 121a to 121e includes the electric circuit 1
The power of the load circuits 105a to 105e is calculated based on the power supply voltage generated by the power supply circuits 123a to 123e based on the power supply from 07 and the current from the CTs 113a to 113e.

That is, the small power measuring devices 121a to 121
When the power of each load circuit is measured by e, it is sufficient to prepare as many small power measuring devices as the number of circuits to be measured, so that there is no waste. Also, since the CT is fixed to the small power measuring device, it can be adjusted according to the CT,
High accuracy. Since the rated current value is also predetermined for each small power measuring device, the rated current value is not set. In this way, the above problem can be solved by the device shown in FIG.

However, in the device shown in FIG. 8, since each small power measuring device takes out a voltage from each load circuit, each power supply circuit 12 is provided in each small power measuring device 121a to 121e.
3a to 123e are required, resulting in high cost.

Further, since each small power measuring device measures data individually, when collecting data,
Data collection work had to be done for each of the small power measuring devices, which was a difficult task.

The present invention provides a multi-circuit power measuring device which can eliminate the waste of the device, guarantee a high measurement accuracy, and need not provide a power supply circuit for each individual measuring device, and can collect data collectively. It is in.

[0015]

In order to achieve the above object, the multi-circuit power measuring apparatus of the present invention is a multi-circuit power measuring apparatus for measuring the power consumption and power consumption of a plurality of load circuits connected to a power distribution system. In the device, a main unit that inputs a power supply voltage from the power distribution system and supplies a voltage signal corresponding to the power supply voltage, and a current detection unit that detects a current flowing through the load circuit and supplies a current signal corresponding to the current. And an individual measuring device which is provided in each of the plurality of load circuits and is supplied with the voltage signal from the main device and is supplied with a current signal from the current detecting unit. Each was detected by the current detector,
It is characterized by comprising power calculation means for calculating the power consumption of the load circuit based on the current signal flowing through the load circuit and the voltage signal supplied from the main device.

According to the multi-circuit power measuring device of the present invention, the multi-circuit power measuring device is composed of the main device and a plurality of individual measuring devices, and the power calculating means provided in the individual measuring device is connected to the power distribution system from the distribution system. Since the voltage signal corresponding to the power supply voltage is input as the common power supply, it is not necessary to provide a voltage signal input circuit, that is, a power supply circuit in each of the individual measuring devices. Therefore, the configuration of the device can be simplified. Also,
Waste of equipment can be eliminated and high measurement accuracy can be guaranteed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a multi-circuit power measuring device according to the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a first embodiment of a multi-circuit power measuring apparatus according to the present invention. The multi-circuit power measuring device shown in FIG. 1 measures the power consumption and the amount of power of a plurality of load circuits 5a to 5c connected to an electric line 7 which is a distribution system via breakers 9a to 9c, and is a main device. 1 and a plurality of individual measuring devices 2a to 2c provided in a one-to-one correspondence with the plurality of load circuits 5a to 5c. Although only three individual measuring devices are provided in this example, the number of individual measuring devices is not limited to this, and two or four or more individual measuring devices may be provided.

The main unit 1 receives a power supply voltage from the electric circuit 7 to generate a DC power supply, and a control circuit 13 operated by the DC power supply from the DC power supply 11.
Then, the power supply voltage from the display unit 14 for displaying data and the electric path 7 is converted into a low voltage which is easily handled by the power calculation circuits (corresponding to the power calculation means of the present invention) 21a to 21c in the individual measuring devices 2a to 2c. The voltage conversion circuit 15 supplies the converted voltage to the individual measuring devices 2a to 2c via the voltage lines 8a and 8b as a common power source.

The individual measuring devices 2a to 2c measure the power consumption and the amount of power of the individual load circuits 5a to 5c, and the power calculating circuits 21a to 21c and the DC power supply 23a to.
23c.

The DC power supplies 23a to 23c are predetermined DC power supplies generated by the DC power supply from the DC power supply unit 11 of the main unit 1, and the voltage of the generated DC power supply is supplied to the power calculation circuits 21a to 21c. Supplied. Power calculation circuit 21
a to 21c calculate the electric power of the load circuits 5a to 5c based on the current signals flowing through the load circuits 5a to 5c and the voltage signal from the voltage conversion circuit 15 of the main device 1 detected by the CTs 3a to 3c. The obtained power values of the load circuits 5a to 5c are output to the control circuit 13 in the main device 1. The control circuit 13 in the main device 1 manages the power values of the load circuits 5a to 5c.

Next, the operation of the multi-circuit power measuring device according to the first embodiment having the above structure will be described.

First, the electric current signals from the CTs 3a to 3c are input to the power calculation circuits 21a to 21c provided in the individual measuring devices 2a to 2c. In addition, the individual measuring devices 2a to
A low-voltage voltage signal obtained by converting the power supply voltage from the electric path 7 is input as a common power supply to the power calculation circuits 21a to 21c provided in 2c.

The power calculation circuits 21a-21c are
Based on the input current signal and voltage signal, the load circuit 5a
Calculate power of ~ 5c. The obtained result is an instantaneous power value. Further, the power calculation circuits 21a to 21c integrate the instantaneous power values and measure the power consumption.

The measured values obtained by the power calculation circuits 21a to 21c are transmitted to the control circuit 13 of the main unit 1, and under the control of the control circuit 13, the individual load circuits 5a to 5c are displayed on the display unit 14. The measured amount of is displayed.

The power supply voltage of the DC power supply unit 11 of the main unit 1 is the DC power supplies 23a-23 of the individual measuring circuits 2a-2c.
The individual measuring devices 2a to 2c are operated by the voltage applied to c and generated by the DC power supplies 23a to 23c.

As described above, according to the multi-circuit power measuring apparatus according to the first embodiment, the power supply voltage from the electric line 7 is converted to the power calculation circuits 21a to 21c provided in the individual measuring apparatuses 2a to 2c. Since a low-voltage voltage signal is input as a common power supply, it is not necessary to provide a voltage signal input circuit, that is, a power supply circuit as shown in FIG. 8, in each of the individual measuring devices 2a to 2c. Therefore, the configuration of the device can be simplified.

Further, the waste of the device can be eliminated.
For example, when measuring the power of the load circuit for only two circuits, it is sufficient to prepare one main device and two individual measuring devices, and this configuration eliminates unnecessary elements. Further, since the individual measuring device is a simple device having a built-in power calculation circuit, it can be constructed at a lower cost than a single measuring device. Therefore, for example, 5
It is possible to solve the problem that a device having a built-in measurement circuit for circuits is used for measurement of only two circuits, and waste of three circuits is generated, and on the other hand, the cost is increased by preparing two single measuring instruments.

The CTs 3a to 3c are the individual measuring devices 2
Since it is one-to-one with a to 2c, the current can be adjusted according to the variation of CT. Therefore, high measurement accuracy can be guaranteed.

Further, the individual measuring devices 2a to 2c are CT3
Since the combination of a to 3c is one-to-one, the one to which the CT of 50A is connected is limited to 50A and used. Therefore, it is not necessary to set the rated current value.

Since the data measured by the individual measuring devices 2a to 2c are transmitted to the main device 1, the main device 1 can collectively collect the measured data.

(Second Embodiment) FIG. 2 is a block diagram showing a second embodiment of the multi-circuit power measuring apparatus according to the present invention. The multi-circuit power measuring device according to the second embodiment shown in FIG. 2 is further weighted in the individual measuring devices 2a _{1 to} 2c _{1 with} respect to the multi-circuit power measuring device according to the first embodiment shown in FIG. It is characterized in that circuits 27a to 27c are provided.

The weighting circuits 27a to 27c have CT3a to 3 for the power values from the power calculation circuits 21a to 21c.
The rated set values 25a to 25c according to c are weighted, and the weighted power value is supplied to the control circuit 13a.

As described above, according to the multi-circuit power measuring apparatus according to the second embodiment, the weighting circuits 27a to 27c adjust the ratings of the power values from the power calculation circuits 21a to 21c according to CT3a to 3c. Set value 25a-25
c can be weighted and the electric power itself of the load circuits 5a-5c can be sent to the main device 1a. In the main device 1a, the measured value itself is the electric power according to the rated current value,
It can be directly read as electric energy.

That is, in the conventional device, it was necessary to set the rating of the CT to be connected for each load circuit, but in the second embodiment, the setting of the current rating value is unnecessary. . Therefore, the troublesome setting work can be omitted. The weighting circuit 27 as shown in FIG.
Even if not a to 27c, a microcomputer (hereinafter, abbreviated as a microcomputer) or the like is built in the individual measuring device, and the function realized by executing the weighting processing program by this microcomputer, that is, the power by software processing. The electric power values from the arithmetic circuits 21a to 21c can be weighted.

(Third Embodiment) Next, a third embodiment of the multi-circuit power measuring apparatus according to the present invention will be described. FIG. 3 is a schematic configuration diagram showing a third embodiment of the multi-circuit power measuring device according to the present invention. FIG. 4 is a main part configuration diagram showing a third embodiment of the multi-circuit power measuring apparatus according to the present invention.

The third embodiment is an example in which the multi-circuit power measuring device is applied to a single-phase three-wire circuit, and the multi-circuit power measuring device is connected to a single-phase three-wire power distribution system which is often used for home wiring. A case of using the load circuit for power measurement will be described.

The multi-circuit power measuring device shown in FIG.
The power consumption and the amount of power of the V loads 6a, 6b, 6d, 6e and the 200V load 6c are measured, and the main device 1b connected to the electric paths 7a to 7c made of a single-phase three-wire and a plurality of loads 6a to 6e. And a plurality of individual measuring devices 2a _{2 to} 2e ₂ provided in a one-to-one correspondence with each other.

The breaker 9a has electric lines 7a and 7b on the input side.
And the output side is connected to the 100V load 6a, and the CT 3a outputs the current flowing in the 100V load 6a to the individual measuring device 2a ₂ . The breaker 9b has an input side connected to the electric paths 7a and 7b and an output side connected to the 100V load 6b, and the CT 3b outputs a current flowing through the 100V load 6b to the individual measuring device 2b ₂ .

The breaker 9c has electric lines 7a and 7c on the input side.
And the output side is connected to the 200V load 6c, and the CT 3c outputs the current flowing in the 200V load 6c to the individual measuring device 2c ₂ . The breaker 9d has an input side connected to the electric paths 7b and 7c and an output side connected to the 100V load 6d, and the CT 3d outputs a current flowing through the 100V load 6d to the individual measuring device 2d ₂ . Breaker 9e
Has an input side connected to the electric lines 7b and 7c and an output side of 100
The CT 3e is connected to the V load 6e, and outputs the current flowing through the 100V load 6e to the individual measuring device 2e ₂ .

As shown in FIG. 4, the main unit 1 includes an electric line 7a.
Direct input of power supply voltage from ~ 7c to generate DC power supply
Current source 11 and the DC power source from this DC power source 11
Control circuit 13 operating more, and the electric power from electric lines 7a and 7b.
Convert the source voltage to a specified voltage and convert the converted voltage to a common voltage.
Individual measuring device 2a via voltage lines 8a, 8b as a source _Two
~ 2e_TwoVoltage conversion circuit 15a supplied to the
Converted by converting the power supply voltage from 7c to a predetermined voltage
Voltage is a common power source and is individually measured via voltage lines 8c and 8d.
Measuring device 2a_Two~ 2e_TwoTo the voltage conversion circuit 15b
have.

The individual measuring devices 2a _{2 to} 2e ₂ measure the power consumption and the amount of power of the individual loads 6a to 6e, and the power calculating circuits 21a to 21e and the voltage selecting section 29a.
.About.29e. In addition, in FIG. 4, although the individual measuring device 2a ₂ has a configuration including the power calculation circuit 21a and the voltage selecting unit 29a, the individual measuring devices 2b _{2 to} 2e ₂ also have the same power as the individual measuring device 2a _2. Arithmetic circuit 21
b to 21e (not shown) and voltage selection units 29b to 29e.
(Not shown).

The voltage selectors 29a to 29e are connected to the voltage line 8a.
To connection terminals a to d connected to 8d, and power calculation circuit 2
1a to 21e are connected to common terminals c1 and c2, a segment 30a1 to be connected to the common terminal c1 and any one of the connection terminals a to d, a common terminal c2 and a connection terminal a to
and a segment 30a2 to be connected to any one of the connection terminals of d.

Further, the voltage lines 8a to 8d are connected to the individual measuring device 2
Similar to the configuration that is connected to the voltage selector 29a of a _2, the voltage line 8a~8d are individually measuring device _{2b 2 ~2e} 2
Of the voltage selectors 29b to 29e.

The power calculation circuits 21a to 21e are connected to the CT3a.
Currents flowing in the loads 6a to 6e and the voltage conversion circuit 15a of the main device 1 and / or the voltage conversion circuit 1 detected by
The electric power of the loads 6a to 6e is calculated based on the voltage from 5b.

As described above, according to the multi-circuit power measuring apparatus according to the third embodiment, in the case of 100V loads 6a and 6b, the breakers 9a and 9b are connected to the electric paths 7a and 7b, so that individual measurement is possible. Voltage selector ₂ in devices 2a ₂ and b 2
9a and 29b, the section 30a1 selects the connection terminal a,
Moreover, the segment 30a2 selects the connection terminal b. For this reason,
The voltage obtained by converting the voltage from the electric paths 7a, 7b by the voltage conversion circuit 15a, that is, the voltage corresponding to the 100V loads 6a, 6b is supplied to the power calculation circuits 21a, 21b.

Further, in the case of 100V load 6d, 6e are breakers 9d, since 9e are connected path 7b, to 7c, the voltage selector of the individual measuring device _2d 2, _e in the ₂ 2
9d and 29e, the section 30a1 selects the connection terminal c,
Moreover, the segment 30a2 selects the connection terminal d. For this reason,
The voltage obtained by converting the voltage from the electric paths 7b, 7c by the voltage conversion circuit 15b, that is, the voltage corresponding to the 100V loads 6d, 6e is supplied to the power calculation circuits 21a, 21b.

Further, in the case of the 200V load 6c, since the breaker 9c is connected to the electric paths 7a and 7c, the voltage selection section 29c in the individual measuring device 2c ₂ has the intercept 30a1.
Selects the connection terminal a, and the section 30a2 selects the connection terminal d.
Select. Therefore, the voltage obtained by converting the voltage from the electric lines 7a and 7c by the voltage conversion circuit 15a and the voltage conversion circuit 15b, that is, the voltage corresponding to the 200V load 6c is supplied to the power calculation circuit 21c.

The power calculation circuits 21a-21e are
The electric powers of the loads 6a to 6e are calculated based on the currents flowing through the loads 6a to 6e and the voltages from the voltage conversion circuit 15a or / and the voltage conversion circuit 15b of the main device 1 detected by the CTs 3a to 3e.

As described above, according to the multi-circuit power measuring apparatus according to the third embodiment, the same individual measuring apparatus can be used to
It is possible to measure the power of a 00V load and the power of a 200V load.

Further, similarly to the multi-circuit power measuring device according to the first embodiment, the data measured by the power calculation circuits 21a to 21e are transmitted to the control circuit 13 of the main device 1b to control the control circuit 13. Below, the measured data is displayed on the display unit 14
It may be displayed in.

Further, as in the multi-circuit power measuring device according to the first embodiment, the DC power supply unit 1 provided in the main device 1b is provided.
The individual measurement devices 2a _{2 to} 2e ₂ by the DC power supply from
It is also possible to generate the DC power supply of No. ₁ and operate the individual measuring devices 2a _{2 to} 2e ₂ by the generated DC power supply.

Further, the multi-circuit power meter according to the first embodiment
As with the measuring device, the individual measuring device 2a _Two~ 2e_TwoWeighted to
A weighting circuit is provided, and the power calculation circuit is
CT3a to 3e for power values from 21a to 21e
The rated set values according to the above are weighted to load 6a to 6e.
The electric power itself may be sent to the main device 1b.

(Fourth Embodiment) Next, a fourth embodiment of the multi-circuit power measuring apparatus according to the present invention will be described. FIG. 5 is a configuration diagram showing a fourth embodiment of the multi-circuit power measuring device according to the present invention. The multi-circuit power measuring device according to the fourth embodiment shown in FIG. 5 is different from the multi-circuit power measuring device according to the first embodiment shown in FIG. 1 in individual measuring devices 2a _{3 to} 2c.
The configuration of ₃ is different.

The individual measuring devices 2a _{3 to} 2c ₃ are DC power supplies 22a to 22c, power calculation circuits 33a to 33c, and central processing units (hereinafter abbreviated as CPU) 35a to 35.
c and.

The power calculation circuits 33a to 33c are analog-to-digital converters (hereinafter abbreviated as ADC) 31a to 31c as voltage measuring circuits for converting the analog voltage signal from the voltage conversion circuit 15 into a digital voltage signal. CT
ADC for converting the analog current signals flowing in the load circuits 5a-5c detected by 3a-3c into digital current signals
32a to 32c, and multipliers 33a to 33c that calculate the electric power of the load circuits 5a to 5c by multiplying the digital voltage signals from the ADCs 31a to 31c by the digital current signals from the ADCs 32a to 32c.

The CPUs 35a-35c have multipliers 33a-
33c, the power values of the load circuits 5a to 5c and the ADC
The digital voltage signals from 31a to 31c and the main device 1c
It is adapted to be transmitted to the internal control circuit 13c.

[0058] According to the multi-circuit power measurement device according to the fourth embodiment, the voltage conversion circuit 1 ADC31a~31c is the main device 1c of the individual measuring device _2a 3 ～2C ₃
5, the voltage signal from 5 is measured and output to the CPUs 35a to 35c, and the control circuit 13c of the main device 1c causes the voltage conversion circuit 1
The value of the voltage signal from the 5 can be read from CPU35a~35c individual measuring device _2a 3 ～2C _3. Therefore, the processing load on the main device 1c can be reduced.

The main unit 1c is connected to the power supply voltage from the electric circuit 7.
Is input, the individual measuring device 2a _Three~ 2c_ThreeOn the voltmeter
Instead of providing a measuring circuit, a voltage measuring circuit is installed in the main device 1c.
Provided, this voltage measuring circuit, input from the electric path 7
The power supply voltage may be measured.

(Fifth Embodiment) Next, a fifth embodiment of the multi-circuit power measuring apparatus according to the present invention will be described. Each of the multi-circuit power measuring devices is often installed in a panel and is in an environment susceptible to noise from many power loads. The individual measuring device integrates the electric energy of the load circuit, but the integrated value may be reset due to the influence of noise.

Therefore, in the multi-circuit power measuring apparatus according to the fifth embodiment shown in FIG. 6, in order to minimize the influence of noise, the individual measuring apparatuses 2a _{4 to} 2c ₄ are provided with integrating sections 37a ...
37c is provided, and the difference value calculation unit 1 is provided in the main device 1d.
7 and integration register 19 are provided.

The integrating units 37a to 37c are connected to the power calculation circuit 2
The power obtained in 1a to 21c is integrated for each collection cycle, and the integrated power amount for each collection cycle is output to the control circuit 13d in the main device 1d. The difference value calculation unit 17 calculates the difference value of the integrated electric energy from the integration units 37a to 37c for each collection cycle, and causes the integration register 19 to integrate the calculated difference value.

As described above, according to the multi-circuit power measuring apparatus of the fifth embodiment, the integrated power amount for each collection cycle obtained by the integrating units 37a to 37c is stored in the difference value calculating unit 17 in the main device 1d. Then, the difference value calculation unit 17 calculates the difference value of the integrated electric energy from the integration units 37a to 37c for each collection cycle. Then, the difference value calculation unit 17 determines whether the difference value is less than or equal to a predetermined value. At this time, the difference value is smaller than the predetermined value if the individual measuring device is normal.
In this case, the calculated difference value is added to the integration register 19.

On the other hand, when the difference value exceeds the predetermined value,
For example, when the integrated electric energy from the individual measuring device is reset due to the influence of noise, the difference value becomes a large value that is theoretically impossible in the collection cycle. In this case, the calculated difference value is not added to the integration register 19. At this time, if the collection cycle is shortened,
It is possible to suppress the influence of the resetting of the integrated electric energy due to noise within a range where there is no practical problem.

[0065]

As described above, according to the present invention, it is possible to eliminate the waste of the device, guarantee a high measurement accuracy, and eliminate the need to provide a power supply circuit for each individual measuring device, and collect the data collectively. A device can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a multi-circuit power measuring device according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of a multi-circuit power measuring device according to the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of a multi-circuit power measuring device according to the present invention.

FIG. 4 is a main part configuration diagram showing a third embodiment of a multi-circuit power measuring device according to the present invention.

FIG. 5 is a configuration diagram showing a fourth embodiment of a multi-circuit power measuring device according to the present invention.

FIG. 6 is a configuration diagram showing a fifth embodiment of a multi-circuit power measuring device according to the present invention.

FIG. 7 is a configuration diagram showing an example of a conventional multi-circuit power measuring device.

FIG. 8 is a configuration diagram showing another example of a conventional multi-circuit power measuring device.

[Explanation of symbols]

1 ... Main device, 2a-2c ... Individual measuring device, 3a-3c ...
Current transformer CT, 5a to 5c ... Load circuit, 7, 7a to
7c ... Electric circuit, 8a-8d ... Voltage line, 9a-9c ... Breaker, 11 ... DC power supply part, 13 ... Control circuit, 14 ... Display part, 15 ... Voltage conversion circuit, 17 ... Difference value calculation part, 19 ...
Integration register, 21a to 21c ... Power calculation circuit, 23a
23c ... DC power supply, 27a to 27c ... Weighting circuit,
29a ... Voltage selection part, 31a-31c ... ADC, 32a
-32c ... ADC, 33a-33c ... Multiplier, 35a-
35c ... CPU, 37a-37c ... Accumulation part.

Claims (8)

[Claims] 1. A multi-circuit power measuring device for measuring power consumption and electric energy of a plurality of load circuits connected to a power distribution system, wherein a power supply voltage is input from the power distribution system and a voltage signal corresponding to the power supply voltage is input. A main device that supplies the current, a current detection unit that detects a current flowing in the load circuit and supplies a current signal corresponding to the current, and is provided in each of the plurality of load circuits, and the voltage signal is supplied from the main device. In addition, an individual measuring device to which a current signal is supplied from the current detecting unit is provided, and each of the plurality of individual measuring devices detects the current signal flowing in the load circuit and the main device. A multi-circuit power measuring device comprising power calculation means for calculating the power consumption of the load circuit based on the voltage signal supplied from the load circuit. 2. The multi-circuit according to claim 1, wherein each of the plurality of individual measuring devices transmits the value of the power consumption of the load circuit obtained by the power calculating means to the main device. Electric power measuring device. 3. The main device includes a DC power supply unit that inputs a power supply voltage from the power distribution system to generate a DC power supply, and supplies the DC power supply of the DC power supply unit to each of the plurality of individual measuring devices. The multi-circuit power measuring device according to claim 1, wherein 4. Each of the plurality of individual measuring devices weights a rated set value in accordance with the current detecting unit with respect to the power consumption from the power calculating means, and weights the power consumption by the main device. The multi-circuit power measuring device according to claim 1, further comprising: 5. The distribution system is configured such that a rated voltage is applied between first and second electric circuits and the rated voltage is applied between second and third electric circuits, and the rated voltage is applied between the first and third electric circuits. A single-phase three-wire circuit to which a voltage twice the voltage is applied, wherein the plurality of load circuits include one or more first loads corresponding to the rated voltage, and one or more first loads corresponding to the voltage twice the rated voltage. And a second load corresponding to the constant voltage between the second and third electric paths and a first voltage signal corresponding to the constant voltage between the first and second electric paths. And a voltage signal to each of the plurality of individual measuring devices, each of the plurality of individual measuring devices, in accordance with the first load or the second load, the first voltage signal from the main device and Select at least one voltage signal with the second voltage signal to select the power The multi-circuit power measuring device according to claim 1, further comprising a selection unit that supplies the calculation unit. 6. Each of the plurality of individual measuring devices comprises voltage measuring means for measuring the value of the voltage signal supplied from the main device, and the value measured by the voltage measuring means is supplied to the main device. The multi-circuit power measuring device according to claim 1, wherein the multi-circuit power measuring device is supplied. 7. Each of the plurality of individual measuring devices includes an integrating unit that integrates the power consumption obtained by the power calculating unit for each collection cycle, and the main device includes the integrating unit in the individual measuring device. 2. The multi-circuit power measuring device according to claim 1, further comprising a difference value calculating means for calculating a difference value of the integrated electric energy from the means for each collection cycle and integrating the calculated difference value. 8. The difference value calculating means integrates the difference values at that time when the calculated difference value is less than or equal to a predetermined value, and when the calculated difference value exceeds the predetermined value. 8. The multi-circuit power measuring device according to claim 7, wherein the difference values at that time are not integrated.