JPH0245418B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention collects the power values of each system in substations or electrical rooms scattered within a factory, etc. in a central monitoring and control center, etc., and calculates the total power value and/or Or it relates to a power value central integration device for calculating and outputting a total power amount value.

Conventionally, when transmitting the electric energy value (KWh) for each system or supply line in an electrical room or substation that is distributed within a factory, etc. to a central monitoring and control center, etc., metric transmission is required. Generally, a method is adopted in which a watt-hour meter with a pulse transmitter is provided for each system, and pulse signals are separately transmitted to a central supervisory control center or the like for each watt-hour meter unit.

The electricity meter with a pulse generator uses an analog voltage signal (generally 0 to 110V) input from a transformer.
and an analog current signal (generally 0 to 5 A) input from a current transformer, the induction disk is rotated to obtain an integrated power value, which is displayed on a counter, and at the same time, the induction disk is A mechanism is added that replaces the rotation of the plate with gear movement and closes the contacts at each constant power value.A voltage is applied from a central monitoring and control center etc. to the opening/closing operation of the contacts. It is designed to send pulse signals to a monitoring control center, etc. Therefore, in a central monitoring and control center, by counting the pulse signals for each fixed period of time (for example, one month), it is possible to obtain the electric energy value during that period.

However, the method using a power meter with a pulse oscillator as described above has the following drawbacks. That is, (1) The power value conversion accuracy of the watt-hour meter with a pulse oscillator is relatively poor, and the watt-hour value per pulse is within the error range. When using a meter,
The pulse time lag causes an error of up to 10KWh.

(2) A watt-hour meter with a pulse transmitter is a meter that detects watt-hour values (KWh), for example,
Since 10KWh is converted as one pulse, it is difficult to calculate the instantaneous power value (KW) from this pulse signal, and it is also difficult to calculate the average power from the number of arriving pulses during a certain period of time. Therefore, even if the instantaneous power value (KW) is calculated, there will be a very large time delay and the accuracy will be poor. In order to improve the measurement accuracy of instantaneous power values, it is possible to increase the number of pulses per 1 KWh or to lengthen the measurement interval, but the former is limited by the calculation speed of the pulse synthesizer and microcomputer. However, the latter method also has the disadvantage of slow response.

(3) The central monitoring and control center, etc. must always be waiting for the arrival of the output pulses from each watt-hour meter with a pulse transmitter, and the central monitoring and control center must always wait for the arrival of the output pulse from each watt-hour meter with a pulse transmitter. Since transmission lines are required for each location, the cost of the entire device is high.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to obtain the total power value and/or total power amount value for each piece of equipment with high accuracy, and the cost of the entire device is low. The purpose is to provide a central aggregation device.

The present invention includes a power value central integration device, a transformer provided for each system for detecting the voltage of each system, and a transformer provided for each system or supply line for detecting the current of each system or supply line. In order to obtain the power value for each system or supply line according to the current transformer provided for each line, the voltage signal of the transformer output, and the current signal of the current transformer output, A power transducer provided for each supply line, an analog multiplexer provided for each substation or electrical room for sequentially receiving power signals output from the power transducer, and analog multiplexer outputs An analog-to-digital converter for converting a signal into a digital signal, and a power value obtained by scanning the digital signal output from the analog-to-digital converter for each system or supply line every unit time. , and an arithmetic processing device provided in a central monitoring and control center for calculating and outputting a power value and/or a power amount value, thereby achieving the above object.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a power value central integration device according to the present invention will be described in detail below with reference to the drawings.

In this embodiment, as shown in FIG. 1, in order to detect the voltage of each system 1 to n before branching to the supply line,
Transformers 10-1 to 10-n provided for each system
, current transformers 12-1 to 12-m provided for each supply line of each system for detecting the current of each supply line 1 to m branched from each system 1 to n, and the transformer 10 -k (k=1~n) output analog voltage signal (0~110V) and current transformer 12-i (i=1~m)
Depending on the output analog current signal (0~5A),
To directly obtain the power value (KW) for each supply line,
Power transducer 1 provided for each supply line
4-1 to 14-m and the power transducer 1
4-i (i = 1 to m) output analog power signal (for example, 4 to 20 mA DC signal proportional to power value)
Substation or electrical room units 1 to 1 to sequentially incorporate
Analog multiplexer 20- provided for each
1 to 20-l and the analog multiplexer 20
-j (j=1 to l) outputs are electrically isolated and amplified by, for example, a photocoupler, and isolation amplifiers 22-1 to 22-l are used to amplify the outputs, and the isolation amplifiers 22-j (j=1 to l) are 1 to 1) Analog-to-digital converter 24-1 provided for each substation or electrical room unit 1 to 1 for converting an output analog power signal into a digital power signal
~24-l and the digital power signals output from the analog-to-digital converters 24-1 to 24-l,
Using the coaxial cables 26-1 to 26-l, the power values obtained by scanning each supply line every unit time are accumulated, and the total power value (KW) and total power amount for each equipment are calculated. (KWh) and an arithmetic processing device 30 provided in the central monitoring and control center for calculating and outputting the
A video display device (hereinafter referred to as a
(referred to as CRT) 32.

The transformers 10-1 to 10-n, the current transformer 12-
1 to 12-m, power transducer 14-1 to
14-m does not detect the electric energy value (KWh) like a conventional electric energy meter with a pulse transmitter,
It directly detects the power value (KW), and all systems that require power detection are provided with the same configuration.

The analog multiplexers 20-1 to 20-
l, isolation amplifier 22-1 to 22-l
and analog-digital converters 24-1 to 24-2
4-l is provided for each substation or electrical room, and the power transducer 14 in that room.
-j's output is taken in and converted into a digital power signal.

The arithmetic processing unit 30 is a central processing unit board (hereinafter referred to as a CPU board) consisting of, for example, a microprocessor, which controls each board and gives commands to each board according to a predetermined procedure. ) 30a, coaxial cables 26-1~
26-l, a communication interface board 30b for receiving digital power signals from each of the analog-to-digital converters 24-1 to 24-l, and a calculation board 30c for performing necessary calculations; A timer board 30d for generating various clock signals, a memory board 30e for storing various programs, data, etc.
for outputting a control signal to the CRT 32 according to the calculation result on the calculation board 30c;
It is composed of a CRT communication board 30f and a bus 30g for connecting the respective boards.

In this arithmetic processing device 30, the CPU board 30a controls each board and gives commands to each board according to a predetermined procedure. However, this command procedure is managed by the timer board 30d, which accurately counts, for example, 100 msec.
A program execution scanning processing command is given to the CPU board 30a every 100 msec. With this program execution scan processing command, from the CPU board 30a,
Community interface board 30
A command is given to b to sequentially read in all digital inputs. The communication interface board 30b controls each of the analog multiplexers 20-1 to 20-l to instantaneously switch each analog quantity in sequence. next,
The input converted into a digital value is passed through the communication interface board 30b.
It is immediately transferred to the arithmetic board 30c, and while taking in the arithmetic program previously stored in the memory board 30e, high-speed arithmetic is performed in accordance with the arithmetic program, and the result is finally stored in the memory board 30e again. The calculation results stored in the memory board 30e are sent as a signal by the CRT communication board 30f to a position according to a screen program stored in advance in the memory board 30e in accordance with instructions from the CRT communication board 30f. It is converted and output and displayed on CRT32.

The action will be explained below.

In this embodiment, all power values are not always input into the arithmetic processing device 30 in parallel. That is, power transducers 14-1 to 14
-m output is always taken into the analog multiplexers 20-1 to 20l, but in the analog multiplexers 20-1 to 20-l, the power transducer is Outputs 14-1 to 14-m (4 to 20 mA) are cyclically selected one by one from 1 to m in time series every 100 msec.

That is, first of all, the power transducer 14-
If only the output of power transducer 14-2 is selected, at the next time, only the output of power transducer 14-2 is selected,
In this way, the power transducers 14-m 1 are taken in one after another until the last power transducer 14-m ₁ belonging to the analog multiplexer 20-1. After the power transducer 14- _m1 , the process is transferred to the analog multiplexer 20-2 in another substation or electrical room, where the same process is performed, and the process is sequentially transferred to other substations or electrical rooms. power transducer 14-m is selected. When this is completed, the process returns to the first power transducer 14-1 and continues repeating the same process again. This cycle
For example, commands are regularly given from the timer board 30d via the communication interface board 30b so that one cycle is completed at approximately 100 msec each time. In this way, the isolation amplifiers 22-1 to 22-l and the analog
The digital converters 24-1 to 24-l always process only one piece of information, so the arithmetic processing unit 30 processes the information once every 100 msec.
This means that all the instantaneous power is captured in chronological order.

The arithmetic processing device 30, on its arithmetic board 30c, operates the transformers 10-1 to 10-1 as shown in the following equation.
10-n transformation ratio PTRi and the current transformer 12-1
The transformation ratio CTRi of ~12-m is multiplied for each input Ii (KW) to calculate the positive power PWi (KW) for each system.

PWi=Ii×PTRi×CTRi…(1) Furthermore, add/subtract the inputs as necessary to calculate the power value TPWj (KW) per equipment,
The results are displayed on the CRT communication board 30.
It is displayed on the CRT32 via f. This allows a highly accurate instantaneous power value (KW) to be obtained. This displayed value is the scan time
Since it is updated every 100msec, the accuracy in terms of time is also good. Moreover, this displayed value becomes useful information for equipment monitoring or diagnosis.

Next, regarding the electric energy value (KWh), the calculation board 30c first calculates the electric power value per equipment that is input to the cycle through the scanning process.
TPWj (KW) is calculated per equipment using the following formula.
Convert to power amount value TPWHj for 100msec.

TPWHj=TPWj×100/60×60×1000 (2) Next, the electric energy value TPWHj is integrally calculated once, and the result is stored in the memory board 30e. Since the scanning time is very short at 100 msec, it is possible to perform integral calculations with high precision except when the instantaneous power value (KW) fluctuates significantly. FIG. 2 shows an example of the relationship between the electric power value TPWj per equipment and the electric energy value TPWHj for 100 msec per equipment.

The calculation results will be displayed within the required period (e.g. 1 hour or
Every 24 hours), the power amount value within that period is called from the memory board 30e and displayed on the CRT 32 via the CRT communication board 30f, similarly to the power value. That is, the above
The electric energy value TPWHj for 100msec is
Integrating 60 x 60 x 1000/100 times will give you the energy value for one hour, and integrating 60 x 60 x 1000/100 x 24 times will give you the energy value for 24 hours.

In the above series of operations, the CPU board 30a reads and processes the control program stored in the memory board 30e.

In this way, by taking in signals in time series and performing calculations sequentially, processing can be performed at low cost using a microcomputer, and a considerable degree of accuracy can be obtained.

In this embodiment, an analog multiplexer 20-j and an analog-digital converter 24-
Since the isolation amplifier 22-j is inserted between the analog multiplexer 24-
up to j, and analog-to-digital converter 24-
J and subsequent parts are reliably electrically isolated, and no problems occur due to the intrusion of noise carried by field signals. Note that depending on the situation, the isolation amplifier may be omitted.

In the embodiment described above, the output of the arithmetic processing device 30 is input to the CRT 32 and the arithmetic results are displayed on the CRT 32, but the means for displaying the arithmetic results etc. of the arithmetic processing device 30 is limited to this. For example, it is also possible to use a printer. It is also possible to immediately input the output of the arithmetic processing device to other control or alarm means, etc., without displaying it.

As described above, according to the present invention, instantaneous power values (KW) and/or power amount values (KWh) can be calculated and output with high accuracy. For example, in the case of a configuration method using a conventional watt-hour meter with a pulse transmitter, a transformer and current transformer with an accuracy of 0.1% class, and a watt-hour meter with an accuracy class of 2.0% (normal class) are used. ,
The overall accuracy of electric energy values is about ±2.5%, and the overall accuracy of instantaneous power values is about ±10%, but according to the present invention, transformers and current transformers with an accuracy of 1.0%, and 0.25% accuracy
When using a class power transducer and a 12-bit analog-to-digital converter, the overall accuracy of instantaneous power values and total accuracy of electric energy values are both within ±
It will be around 1.4%. Moreover, the cost of the entire device is lower than that of the conventional device. That is, the power transducer alone is more expensive than the power meter with a pulse oscillator, but the analog multiplexer and subsequent components are cheaper overall because of the shared time series processing. Furthermore, the calculated output of the instantaneous power value has excellent effects such as enabling equipment protection, status monitoring, and diagnosis.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a power central integration device according to the present invention, and FIG. 2 is an example of the relationship between electric power values and electric energy values to explain the operation of the embodiment. FIG. 10-1 to 10-n...transformer, 12-1 to 1
2-m... Current transformer, 14-1 to 14-m... Power transducer, 20-1 to 20-l... Analog multiplexer, 22-1 to 22-l... Isolation amplifier, 24 -1~24-l...
Analog-digital converter, 30... Arithmetic processing unit, 32... Video display device (CRT).

Claims (1)

[Claims] 1 A transformer installed in each system to detect the voltage of each system, and a current transformer installed in each system or supply line to detect the current of each system or supply line. , a power transformer device similarly provided for each system or supply line to obtain a power value for each system or supply line according to the voltage signal of the transformer output and the current signal of the current transformer output. an analog multiplexer provided in each substation or electrical room unit for sequentially taking in the power signal output from the power transducer, and an analog multiplexer for converting the analog signal output from the analog multiplexer into a digital signal. - The digital converter and the digital signal output from the analog-digital converter are scanned every unit time for each system or supply line, and the power values obtained are integrated, and the power value and/or the power amount value is calculated. 1. A power value central aggregation device, comprising: an arithmetic processing device provided in a central monitoring and control center for calculating and outputting.