JPH08317476A - Transmission terminal equipment - Google Patents

Abstract

PURPOSE: To easily measure the electric quantities of the branch parts of a distribution system for respective branches. CONSTITUTION: This transmission terminal equipment 1 installed at the installation site of an electric circuit to be monitored is constituted of a selector 17 for selecting the current signals of more (than two sets of the electric circuits to be monitored at a prescribed timing, an analog/digital converter 19 for converting the selected current signal to a digital value, a storage means 26 for storing the converted digital value, a rated value setting part 22 for setting a rated value corresponding to the respective electric circuits to be monitored, a central processing unit 8 for performing arithmetic operations based on contents set by the rated value setting part 22 for the stored contents, a transmission part 24 for communicating the result of the arithmetic operation with a host device and a case body for integrally housing them in the inside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission terminal device for measuring various electric quantities of a distribution system on site and transmitting them to a centrally installed host device, and more particularly, to a quantity of electricity for each branch (feeder) of the distribution system. The present invention relates to a transmission terminal device suitable for measurement and transmission to a host device.

[0002]

2. Description of the Related Art Measurement and monitoring of various amounts of electricity in a power receiving and distribution system in factories, buildings, etc. are necessary for stable power supply and grasping load conditions. For example, Japanese Unexamined Patent Publication No. 60-186007 describes a conventional technique for monitoring a transformer, and Japanese Utility Model Laid-Open No. 61-14854 discloses a conventional technique for monitoring the maximum power demand. Has been described.

Since the facility and apparatus for measuring and monitoring the power receiving and distributing system have a high investment cost, the object of measurement and monitoring is limited to an important place as in the above-mentioned prior art. For example,
When measuring and monitoring the branch part of the distribution system, if there are five branch circuits, do not measure and monitor each of all five of them, but measure and monitor only the important branch circuits. ing. Because the amount of electricity is different for each branch circuit, the instrument transformer (CT), the instrument transformer (VT), and the signal conversion transducer that are attached to the branch circuit must be rated according to the installation location. This is because there is a problem that it must be used.

Further, when calculating the amount of electricity from the measured data, since the calculation according to the rating of the measuring instrument is required, the data collected by the instruments with different ratings from a large number of points are collectively collected by the central computer. Then, there is a problem that it is not easy to calculate. Therefore, conventionally, for example, when measuring and monitoring the electric quantity of two important branch electric lines of five branch electric lines, a measuring / monitoring device (controller) dedicated to the branch electric lines is installed for each branch electric line. There is.

[0005]

[Problems to be Solved by the Invention] In recent years, more and more energy saving has been demanded, and detailed measurement and monitoring have been demanded. That is, in the above example, when there are five branches, it is necessary to measure and monitor all five branch circuits. However, when performing such fine-tuned measurement / monitoring, if the measurement / monitoring is performed by extension of the conventional way of thinking, it is necessary to install a transducer or controller for each branch electric line, and the equipment cost becomes huge. There is a problem that it is not appropriate. That is, 1) It is necessary to select a transducer according to the CT or VT rating for each branch, and it is not easy to determine the specifications.

2) The controller or the central unit needs to perform calculation processing in accordance with the CT for each branch, which is complicated.

3) When the CT specifications change, it is necessary to change the transducer and the calculation process of the controller or the central unit.

4) The number of man-hours for wiring the transducer, A / D converter, etc. is large.

5) The installation area is large when the transducers and the like are gathered together.

6) The investment cost is high.

There is a problem.

An object of the present invention is to solve all of the above-mentioned problems, and a transmission terminal device which can easily perform fine measurement / monitoring of a branch portion of a power distribution system, that is, a branch terminal has the highest need. An object of the present invention is to provide a transmission terminal device that can measure “voltage”, “power”, and “power amount” mainly by measuring “current” for each branch with one small device.

[0013]

Means for Solving the Problems The above-mentioned object is to select a transmission terminal device installed at a site where a monitored electric circuit is installed, and selecting means for selecting current signals of two or more sets of monitored electric circuits at a predetermined timing. Analog / digital converting means for converting the current signal into a digital quantity, storage means for storing the converted digital quantity, rated value setting means for setting a rated value corresponding to each of the monitored electric circuits, and the storage means. The central processing unit that calculates the contents based on the contents set by the rated value setting unit, the transmission unit that communicates the result of the calculation between the host device, the selecting unit, and the analog / digital converting unit. And the storage means, the rated value setting means, the central processing unit, and the transmission means are integrally housed in a housing.

The above-mentioned object is also to select a transmission terminal device installed at the installation site of the monitored electric circuit at a predetermined timing from current signals of two or more monitored electric circuits and voltage signals of one set of monitored electric circuits. Selecting means, an analog / digital converting means for converting the selected current signal and voltage signal into a digital quantity, storage means for storing the converted digital quantity, and setting a rated value corresponding to each of the monitored electric circuits. A rated value setting means, a central processing unit that calculates the stored content based on the content set by the rated value setting means, a transmission means that communicates the result of the calculation between a host device, and A housing for accommodating the selection means, the analog / digital conversion means, the storage means, the rated value setting means, the central processing unit, and the transmission means in an integrated manner. In By configuring it is accomplished.

The above object is also to select a transmission terminal device installed on the installation site of the monitored electric circuit from a current signal of two or more sets of monitored electric circuits and a voltage signal of one set of monitored electric circuits at a predetermined timing. Selection means, analog / digital conversion means for converting the selected current signal and voltage signal into digital quantities, storage means for storing the converted digital quantities, and rated values corresponding to each of the monitored electric circuits are set. Rated value setting means, phase wire type setting means for setting the phase wire type of the monitored circuit, contents set by the rated value setting means for the stored contents and set by the phase wire type setting means A central processing unit that performs an operation based on the contents, a transmission unit that communicates the result of the operation between a higher-level device, the selection unit, the analog / digital conversion unit, and the storage unit. By configuring in a housing for accommodating the integral means and the nominal value setting means and said central processing unit and the transmission means therein, is achieved.

[0016]

The current values of all the branch circuits are taken into one transmission terminal device having the above-mentioned configuration, and the central processing unit calculates various electric quantities according to the ratings of the respective current values and the calculated results are stored in the higher order. Transmit to device. This eliminates the need to install transducers of different ratings in one branch circuit, and the calculation of various amounts of electricity based on each rating is performed by the transmission terminal device installed in the field, while the host device installed in the center uses various electrical devices. It is not necessary to calculate the quantity.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a block configuration diagram of a transmission terminal device according to a first embodiment of the present invention. The transmission terminal device 1 is configured as an integrated unit by including the components and devices described below in one housing. In this transmission terminal device 1, 2 is a voltage input unit, 2a, 2b and 2c are terminals for supplying power to the transmission terminal device 1 and 3 is a circuit for converting the supplied power into a voltage suitable for each unit described below. A power supply unit for supplying each unit and corresponding to an input voltage of 85V to 264.
Reference numeral 4 is a signal transformer, 5 is a comparator for converting an alternating current signal into a predetermined rectangular wave direct current signal, and 16 is an IC for shaping a waveform. Reference numeral 7 is a signal line for transmitting the shaped rectangular wave signal, which is a frequency detection signal line.

Reference numeral 8 denotes a central processing unit such as a microcomputer (hereinafter,
It is called a CPU. ) Is the main purpose of the calculation processing of the current signals of the two or more sets of monitored electric circuits, and each unit is integrally controlled. Reference numeral 9 denotes an R for storing the above-mentioned arithmetic processing and overall control procedure.
OM (Read-On Memory), 10 is a RAM (Random Access Memory) for storing calculation results and progress.
These ROM 9 and RAM 10 are built in the CPU 8.

Reference numerals 11a, 11b, ..., 11n each denote a current input portion for taking in a current signal from a pair of monitored electric circuits.
Four terminals 2a, 12b, 12c and 12d, an internal current transformer 13, an amplifier 14 and a sample hold.
It is composed of a circuit 15. Reference numeral 6 is a holding command signal line for giving an instruction to the sample hold circuit 15, and 17 is a selecting section (multiplexer) for selectively selecting signals from the plurality of input sections at a predetermined timing. Is indicated by control line 18.

Reference numeral 19 is an A / D converter (A / D converter) for converting the signal (analog signal) selected by the selector 17 into a digital amount (value). 20, 21
Is a control line for giving a conversion instruction to the A / D converter 19 and detecting the end of conversion. 22b, 22c, ..., 2
2n is a setting unit provided corresponding to CT 105a, ...
The primary rating of CT is set. Also, 22a
Is a setting unit for setting the primary rating of VT.

Reference numeral 23 is an address setting unit for setting a unique address of the transmission terminal device 1, and a plurality of addresses are connected to the host device when communicating with the host device installed in the central control room or the like. Each of the transmission terminal devices is assigned an address. A transmission unit 24 communicates with a higher-level device and has a terminal 2
5, the transmission line, which will be described later, is connected to the host device.
Reference numeral 27 is an amplifier of the same kind as the above-mentioned amplifier 14 for amplifying a voltage signal.

FIG. 2 is a block diagram of a system in which the transmission terminal device 1 shown in FIG. 1 is applied to a power distribution system. 102 is a transformer (TR), 103 is a fuse (F) 104 is an instrument transformer (VT) 105a to 105e is an instrument current transformer (C)
T). 106 is a transformer such as a secondary substation (T
R) and 107a to 107e are CT. Reference numeral 108 denotes various loads such as an electric motor, a lighting device, a computer, and an air conditioner.

Reference numeral 100 denotes a central device, which is a computer (general-purpose personal computer or the like) for collecting and monitoring the results of measurement and calculation by a plurality of transmission terminal devices 1 installed at each site. 10
Reference numeral 1 is a transmission line that connects each transmission terminal device 1 and the central device 100.

FIG. 3 is a detailed physical connection diagram of the monitored electric circuit of the distribution system and the transmission terminal device 1 shown in the single line diagram of FIG. The physical connection diagram of FIG. 3 shows a three-phase three-wire system among various phase wire systems, and is the most general one in a distribution system. In the figure, R, S, and T indicate the phases of the distribution line. For easy understanding, R indicates the R phase, S indicates the S phase, and T indicates the T phase. Therefore, at least two locations for current measurement / monitoring by such a phase wire system are required for one branch, and CT is shown as 105aR, 105aT in the figure. The same applies to the single-phase three-wire system.

FIG. 4 shows the setting units 22a and 2 in FIG.
The detailed circuits 2b to 22n and the correspondence of the setting unit to the primary ratings of VT and CT are shown. 220 and 221 are resistors for establishing a potential.

FIG. 5 is a front view of the transmission terminal device 1.
Parts indicated by reference numerals correspond to those in FIG. In addition, terminal 2
The a to 2c, 12a to 12d, 25 and each setting unit can be covered with covers 223 and 224.

Next, the operation of the above-mentioned transmission terminal device 1 will be described. FIG. 6 shows a basic method for obtaining a measurement value by sampling (extracting) an alternating current signal at a predetermined timing. In this embodiment, one cycle of alternating current is sampled 12 times.

The execution value I of the current is calculated by squaring each sampling value (i1 to i12), adding one cycle, and then dividing by the sampling number n (12) as shown in the equation. It can be calculated by taking the root. The same applies to voltage. Further, in this embodiment, the calculation result is obtained in one cycle after sampling.

An example in which the number of branches in the branch portion is "8" will be described below. FIG. 7 is a flowchart showing a power-on process procedure. First, in S1, internal initial processing is performed. In S2, a rectangular wave check of the frequency detection signal line 7 of FIG. 1 is performed to determine whether the frequency is 50 Hz or 60 Hz, and the sampling interval is determined based on the determination result. That is, 50
In Hz, one cycle is 1/50 second, so the sampling interval is 1 / (50 × 12) second, and in 60 Hz, 1/50 second.
(60 × 12) seconds.

The next step S3 takes into consideration the case where the calculation process shown in FIG. 6 ends early, and the next sampling start timing (for example, the rising edge of the rectangular wave) is checked. Then, in S4, the sampling interval is set to the CPU8.
It is set in the internal timer of so that interrupt processing can be performed at a predetermined timing. In the next step S5, the timer interrupt is released so that the interrupt process can be performed, and the system waits for an interrupt.

FIG. 8 is a flowchart showing a timer interrupt processing procedure. The time of this interrupt interval is the time of the above-mentioned sampling interval. First, in S6, a hold command is issued via the hold command signal line 6 described above, and then the process proceeds to S7. In S7, first, in S7a, the selection unit 1
Select the first channel of 7 (in this case R of the monitored circuit)
(Corresponding to the voltage between the phase and the S phase), and then in S7b, a conversion command is issued to the A / D conversion unit 19. Next, in S7c, it is determined whether or not the conversion is completed. If it is not completed, the completion is waited, and if it is completed, the process proceeds to S7 and the converted digital amount (value)
Is read out and stored in the RAM 10. The storage location will be described later with reference to FIG.

Next, in S8, the second channel of the selection unit 17 is selected (in this case, it corresponds to the voltage between the S phase and the T phase of the monitored circuit), and the same processing as in S7 is performed. In the next S9, the third channel of the selection unit 17 is selected (in this case, it corresponds to the R phase of CT of the monitored circuit), and the same processing as in S7 is performed. In S10, the fourth channel of the selection unit 17 is selected (in this case, it corresponds to the T phase of CT of the monitored circuit), and the above S7 is selected.
Perform the same processing as. Thereafter, in the same manner, processing is sequentially performed up to the 18th channel corresponding to the CT of the monitored electric circuit in the other branch portion. This series of processes corresponds to v1, i1 shown in FIG.
Is the timing corresponding to the position.

In S12, it is checked whether or not the number of times of sampling of one cycle of the alternating current described above, that is, 12 times in the present embodiment, is completed, and if it is not completed, the process proceeds to S13 and the storage location is updated. In step S14, the reception interrupt described later is released, and the next sampling timing (ie, v in FIG. 6) is released.
Wait for the interrupt to occur at position 2 and i2).

In this way, when a series of processes of 12 times in one cycle is completed, the process proceeds to S15, the timer interrupt is prohibited (that is, sampling process), the reception interrupt is canceled in S16, and the process proceeds to the calculation process S17. The calculation process will be described later with reference to FIG. Next, when the calculation process is completed, the process proceeds to S18, the timing check is performed as in S3, the timer interrupt is released in S19, and the standby state, that is, the interrupt waiting state is entered.

FIG. 9 is a flow chart showing a reception interrupt processing procedure. This process is a process for communicating with the higher-level device 100. The reception interrupt has a lower priority than the timer interrupt processing described with reference to FIG. 8, and the processing is performed when the reception interrupt is released.

First, the contents received in S40 are checked for a communication failure, and then in S41 the start address of the data to be transmitted (calculation result shown in FIG. 12) is set. In S42, the transmission is ready. If it is possible to transmit, the data at the location indicated by the above address is read out and transmission is performed at S44. In the next S45, it is checked whether or not all of the above data have been transmitted. If not, the data address is updated in S46 and the process returns to S42. When the transmission of all the data is completed, the original processing, that is, the standby state is returned. Alternatively, the processing is returned to the middle of the calculation processing of S17 and continued.

FIG. 10 is a flowchart showing the calculation processing procedure in the three-phase three-wire system and the single-phase three-wire system. Figure 11
FIG. 9 is a diagram showing sampling performed at a predetermined timing as described with reference to FIGS. 6 and 8, converted into a digital amount by the A / D converter 17, and stored in the readable / writable RAM 10. 12 is a diagram showing an example in which the result of the calculation process shown in FIG. 10 is stored.

First, the line voltage between the R phase and the S phase is calculated in S30 from the sampled data shown in FIG. 11, and the basic calculation is as shown in FIG. Then S
Similarly, the line voltage between the S and T phases is obtained at 31, and the line voltage between the T and R phases is calculated at S32. The line voltage between the T and R phases in the three-phase three-wire system and the single-phase three-wire system is 0
It is known that it can be obtained by subtracting from.

Next, in S33, the input unit 11 shown in FIG.
The calculation is performed for the current corresponding to a. That is, the R-phase current is calculated in S33a and the T-phase current is calculated in S33b, and the result of the S-phase is obtained by subtracting from 0 as shown in S33c, like the above voltage. In S34, the current corresponding to the input unit 11b shown in FIG. 1 is calculated, which is similar to S33.

As described above, the currents are calculated one after another, and in the present embodiment, the currents for eight sets are calculated, and the results are stored in each storage area of the RAM 10 as shown in FIG.

In the above embodiment, the calculation process of one set of voltages is included, but this calculation process can be omitted. Further, in the flowchart shown in FIG.
Although the detailed calculation regarding the conversion calculation for the primary rating of VT and CT shown in FIG. 4 and the resolution of the amplifiers 14, 27 and the A / D converter shown in FIG. 1 is omitted, the calculation is collectively performed after the calculation for obtaining each root. Obviously, you can.

According to the above-described embodiment, it is possible to measure and monitor a plurality of currents and voltages in the branch portion in the three-phase three-wire system and the single-phase three-wire system.

Next, FIG. 13 shows an application example of the present invention.
~ It demonstrates with reference to FIG. FIG. 13 is a diagram in which the transmission terminal device 1 described above is connected to a single-phase two-wire system. In this embodiment, the power supply terminals 2b and 2c are short-circuited at the terminals, and the voltage between the S phase and the T phase described above is "0". FIG. 14 shows a calculation flowchart of a single-phase two-wire system, which is calculated based on the sampling data shown in FIG. 14 is different from the first embodiment described above in that voltage calculation is for one phase (between R and S) and current calculation is not for S phase. Further, FIG. 15 shows a storage example of the calculation result.

That is, in this embodiment, the extra calculation is omitted from the three-phase three-wire system and the single-phase three-wire system, but from the opposite idea, the calculation process of the first embodiment can be used as it is. This shows that there is no problem.

In the first embodiment, the current measurement of the three-phase three-wire type and the single-phase three-wire type with the number of branches of 8 was shown, but in the present embodiment, the number of branches of the single-phase, two-wire type is determined depending on the application. This means that 16 currents can be measured.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. The purpose of the second embodiment is to enable measurement of the currents, electric powers, and electric energy of two or more sets of monitored electric circuits in the branch portion.
The current measurement of the three-phase three-wire system and the single-phase three-wire system has been described above in the first embodiment, and therefore omitted, and the measurement of power and power amount will be described below.

FIG. 16 shows the power for a single phase, and it is well known that the average of the products of the current and voltage for one cycle of alternating current (ΔP in the figure) is defined as the power. Is. Therefore, the product of the current i and the voltage v sampled at each predetermined timing described in FIG. 6 is added for one cycle and divided by the number of times of sampling to obtain the electric power. In addition, the electric energy is obtained by multiplying the electric power by time, and the accumulated electric energy is obtained by multiplying ΔP and Δt shown in the figure and accumulating the results.

Next, the calculation procedure will be described with reference to FIG. First, based on the voltage and current sampling data described in FIG. 11, the power of the portion corresponding to the input unit 11a is calculated in S60. In S60a, the power between the R and S phases is obtained. Next, in S60b, the electric power between the S phase and the T phase is obtained. In the next step 60c, the electric power for one branch is obtained by the two-power meter method. Similarly, the other current input units 11b, ...,
Corresponding to 11n (8 branches in this example), S61 and S6
Calculation is performed in order of 2.

In S63, the amount of electric power is calculated. However, as explained in FIG. 6, since the calculation process is monopolized in the next cycle,
Multiply by “2”, accumulate and store the result. Such processing is sequentially performed in S64 and S65, and the result is stored in the RAM 10 as shown in FIG. After this, the current calculation shown in FIG. 10 is performed. FIG. 18 is a diagram showing an example in which the calculation results of the power and the power amount are stored. In the figure (△ PRS),
(ΔPST) indicates the power between each line.

In this embodiment, the calculation of the amount of electric power is performed after the calculation of the total amount of electric power, but it goes without saying that it may be calculated immediately after the calculation of the electric power of each part. Although the calculation processing time shown in FIG. 6 is shown as one cycle, it goes without saying that if the calculation processing time is long, it may be extended to the next cycle and tripled.

Next, an application example of the second embodiment is shown in FIG.
9, referring to FIG. FIG. 19 shows a calculation flow chart of electric power and electric energy in the single-phase two-wire system. S70 and S71 are 105aR, 10a shown in FIG.
This is the step of calculating the power equivalent to 5aT, and S
60a is the same as in FIG. S71 (60b ') is
Unlike S60b shown in FIG. 17, the voltage sampling data is the same as the product of S60a, which is the product of the voltage between R and S and the current of the T phase, but the rest is the same. Similarly, power calculation for 16 points is performed in the order of S72, S73, and S74. Then, the electric energy is calculated in S75, and S7 is calculated.
6, S77 and the electric energy for 16 points are calculated sequentially.

The results of these calculations are stored in a predetermined position in the RAM 10 as shown in FIG. Here, "-" in the figure indicates an empty space, but the meaning can be understood by comparing with FIG. That is, the idea is unified with the ideas of the three-phase three-wire system and the single-phase three-wire system. However, in the calculation processing procedure, since the voltage is different as described above, the ROM 9 storing the processing procedure is different.

In the description of FIG. 1, the description of the power failure detection unit 28 and the negative non-volatile storage unit 26 is omitted, so that they will be described below. The power failure detection unit 28 operates by receiving the output of the waveform shaping circuit 6. That is, a power failure is detected, and this is promptly transmitted to the CPU 8 via the power failure detection signal line 29, and the calculation result of the power amount is stored in the non-volatile storage unit 26.

The non-volatile storage section 26 is, for example, EEPRO.
M (Electrical / Erasable / Pro)
grammable / Read / Only / Memmo
ry). This element is an electrically erasable and rewritable memory element that can be permanently stored.

When the power is restored, the contents of the non-volatile storage section 26 are transferred to the position of the power amount calculation result of the RAM 10 in the initial processing of the power-on flowchart shown in FIG. 7, and the calculation result is continuously obtained. It is possible to accumulate.

Next, the third embodiment of the present invention will be described with reference to FIG.
21 and FIG. 21. In the above-described second embodiment, the ROM 9 is dedicated because the power calculation process is different between the three-phase three-wire system and the single-phase three-wire system and the single-phase two-wire system. However, considering the standardization of the product, Not preferable. Therefore, in the present embodiment, in order to solve this, the phase line type determination processing shown in FIG. 21 is performed.

Therefore, the VT primary rating setting unit 2 shown in FIG.
The CPU uses the bit No. 4 (222) of 2a to judge the phase wire system, and performs the calculation processing of the flowchart shown in FIG. That is, prior to the calculation processing, in S47, the single phase 2
Wire type (bit No. 4 of the VT primary rating setting section is on)
If it is not a single-phase two-wire system, it is determined in S48 that three-phase three
Wire-type (the same applies to single-phase 3-wire type)
In S49, the voltage / current is further calculated. In the case of the single-phase two-wire system, the process proceeds from S47 to S50, and the single-phase two-wire system voltage / current calculation is performed after the single-phase two-wire system power / power amount calculation. The content of the calculation process is as described in the first and second embodiments. The procedure of the calculation process is stored in the ROM 9.

As described above, the transmission line terminal 1 can be used according to the phase line type of the branching portion by performing the phase line type determination. Therefore, standardization of the product is achieved, and the user does not have to worry about model selection.

By the way, the electric quantity measurement in the second and third embodiments was voltage / current, electric power / electric energy, but if sampling data of voltage / current is available, reactive power, reactive power can be obtained. The amount can be calculated. Although detailed description is omitted, it is a known fact that the reactive power is obtained by the product of voltage and current having a phase difference of 90 °. Further, it is needless to say that the power factor can be calculated when the electric power (active power) and the reactive power are obtained.

[0060]

According to the present invention, the specification can be easily measured by one device without worrying about the CT primary rating and the VT primary rating for each branch portion in the power distribution system, and the central device can be used. Concentrated monitoring is possible. Further, since the transmission terminal device itself performs each calculation and transmits it to the host device, the load on the central device is reduced, and further, even if the CT or VT is changed, the transmission terminal device can cope with it. There is also an effect that it is not necessary to change the calculation process.

Further, the effect of reducing the number of wiring work steps and the installation area is great. Furthermore, the ability to measure the amount of electricity and the amount of electricity for each branch in the branch part allows the detailed energy usage state for each load to be grasped, which is useful for energy saving measures. Furthermore, by being able to judge the phase line type, there is a great effect that one unit can perform measurement according to the phase line type of the distribution system, which greatly reduces investment costs and has a great effect on the stable supply of the distribution system. .

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a transmission terminal device according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram in which the transmission terminal device shown in FIG. 1 is arranged in a power distribution system.

FIG. 3 is a physical connection diagram in a three-phase three-wire system (similar to a single-phase three-wire system).

FIG. 4 is a detailed view of a setting unit that sets the primary rating of CT and VT and a diagram showing the setting correspondence content of the setting unit for the primary rating.

FIG. 5 is a front view of a transmission terminal device.

FIG. 6 is a diagram illustrating sampling and current / voltage calculation formulas.

FIG. 7 is a flowchart showing a processing procedure when the power is turned on.

FIG. 8 is a flowchart showing a timer interrupt processing procedure.

FIG. 9 is a flowchart showing a reception interrupt processing procedure.

FIG. 10 is a flow chart showing a three-phase three-wire / single-phase three-wire calculation processing procedure.

FIG. 11 is a diagram showing an example of storage of sampling data.

FIG. 12 is a diagram showing a storage example of a three-phase three-wire / single-phase three-wire calculation result.

FIG. 13 is a physical connection diagram of a single-phase two-wire system.

FIG. 14 is a current calculation flowchart for a single-phase two-wire system.

FIG. 15 is a diagram showing a storage example of a calculation result of a single-phase two-wire system.

FIG. 16 is a diagram illustrating power calculation.

FIG. 17 is a calculation flowchart of electric power and electric energy of a three-phase three-wire system (same for a single-phase three-wire system).

FIG. 18 is a diagram showing an example of storage of power / power amount calculation results.

FIG. 19 is a single-phase two-wire type power / power amount calculation flowchart.

20 is a diagram showing a storage example of the result of FIG.

FIG. 21 is a flowchart for performing processing by determining the phase line method.

[Explanation of symbols]

1 ... Transmission terminal device, 2 ... Power supply terminals 11a, 11b, 11
n current signal input unit, 17 ... selection unit, 19 ... A / D conversion unit, 8 ... central processing unit, 22a ... VT primary rating setting unit,
22b, 22c, 22n ... CT primary rating setting unit, 24 ...
Transmitter 222 Phase wire type judgment bit.

Claims (3)

[Claims] 1. A selecting means for selecting current signals of two or more sets of monitored electric circuits at a predetermined timing, an analog / digital converting means for converting the selected current signals into a digital quantity, and storing the converted digital quantity. Storage means, a rated value setting means for setting a rated value corresponding to each of the monitored electric circuits, a central processing unit for calculating the stored contents based on the contents set by the rated value setting means, A transmission means for communicating the result of the calculation with a host device, the selection means, the analog / digital conversion means, the storage means, the rated value setting means, the central processing unit, and the transmission means are integrated inside. A transmission terminal device, comprising: a housing that is housed in the monitoring terminal, and is installed at a site where the monitored electric circuit is installed. 2. A selecting means for selecting at least two sets of current signals of the monitored electric circuit and one set of voltage signals of the monitored electric circuit at a predetermined timing, and the selected current signal and voltage signal are converted into digital quantities. Analog / digital conversion means, storage means for storing the converted digital amount, rated value setting means for setting a rated value corresponding to each of the monitored electric circuits, and the rated value setting means for the stored contents. A central processing unit that performs an operation based on the set contents, a transmission unit that communicates the result of the operation between a host device, the selection unit, the analog / digital conversion unit, the storage unit, and the rated value setting. Means, the central processing unit, and a casing that integrally accommodates the transmission means therein, and is installed at the installation site of the monitored electric circuit. Transmission terminal equipment. 3. Selection means for selecting at least two sets of current signals of the monitored electric circuit and one set of voltage signals of the monitored electric circuit at a predetermined timing, and converting the selected current signals and voltage signals into digital quantities. Analog / digital conversion means,
Storage means for storing the converted digital amount, rated value setting means for setting a rated value corresponding to each of the monitored electric circuits, phase line type setting means for setting a phase wire type of the monitored electric circuits, and Transmission for communicating the result of the calculation between a central processing unit that performs calculation based on the contents set by the rated value setting unit and the contents set by the phase wire setting unit for the stored contents, and a higher-level device Means, and a housing for accommodating the selection means, the analog / digital conversion means, the storage means, the rated value setting means, the central processing unit, and the transmission means in an integrated manner. A transmission terminal device, which is installed at a site where an electric circuit is installed.