JPH06189371A - Monitor control system - Google Patents

Abstract

PURPOSE:To realize the monitor control system sending efficiently data of analog signal waveform. CONSTITUTION:When voltage current waveform data on a fault are sent from a slave station 10 to a master station 20, the data are once subject to fast Fourier transformation by the slave station 10 and a spectrum is obtained and it is sent as telemeter data. The master station 20 reproduces a waveform at the fault based on the spectrum. Thus, the quantity of data is remarkably reduced and the efficient transmission is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supervisory control system capable of efficiently transmitting analog signal waveform data.

[0002]

2. Description of the Related Art For example, in a power system network, a plurality of substations or power plants are integrated as one group, and one control station performs monitoring control.

Generally, the control station side is called a master station, and the side where controlled equipment such as a substation exists is called a slave station. The master station and slave stations are connected by a communication line, and a system is constructed by exchanging data necessary for monitoring and control.

When an accident such as disconnection of a circuit breaker occurs at a substation or a power plant, the occurrence of the accident is transmitted to the control station, and the post-accident process is performed at the control station. Then, a central monitoring station located at a higher level is notified. When trying to analyze the cause of an accident, it is convenient to be able to notify the waveform data such as voltage and current at the time of the accident.

Therefore, in the conventional slave station, the above-mentioned fault voltage and current are input as analog signal waveform data, and after A / D conversion, digital signal data is stored on the memory as digital signal data in accordance with sampling of a predetermined fine cycle. Was stored in. In order to analyze the accident from the master station, when the slave station receives a request for fault voltage and current data, the slave station transmits the sampled value data as telemeter data without processing it.

In the case of a supervisory control system using a computer, the master station draws the fault voltage and current data as analog signal waveforms on the CRT, for example, on the basis of the telemeter data to identify the cause of the fault. I was doing an analysis.

[0007]

Although it is possible to transmit the data as it is as telemeter data without processing the sampling data, the amount of data becomes enormous. Generally, in the supervisory control system of the power grid that requires quick response, the sampling period is
A value of about 1.66ms (600Hz) is used.

The required fault voltage and current data amount varies depending on the system, but is a value of, for example, about 100 bytes when the number of circuits operating in the event of a fault and the number of each phase are taken into consideration. If the maximum accident duration is 10 seconds, the amount of data is 100 bytes x 8 bits x 600Hz x 10 seconds = 4.800.000 bits. Assuming that this amount of data is transmitted at a transmission rate of 1200 bits / sec that is normally used between the master station and the slave stations, 4.800.000 bits / 1200 bits / sec = 4000 seconds, that is, about 1.1 It will take hours and hours.

According to the present invention, as a method of transmitting the above-mentioned fault voltage and current data from the slave station to the master station, the sampling value is not transmitted as it is, but the slave station once performs high-speed Fourier transform to convert the spectrum value. Data is calculated by transmitting the spectrum value as telemeter data.
The purpose is to reduce the amount of data and to perform efficient data transmission. Furthermore, in the master station, based on the spectrum value transmitted from the slave station, the fault voltage and current data are concerned.
The present invention is intended to provide a supervisory control system capable of reproducing data.

[0010]

In order to achieve the above object, the present invention transmits information required for monitoring and control between a control station (master station) and a controlled station (slave station). Fit
In a supervisory control system that monitors and controls controlled equipment,
In the slave station, an A / D converter that converts the analog signal waveform that is input from analog to digital, a sampling processor that samples the data after A / D conversion in accordance with a preset sampling cycle, and a sampling A sampling value storage unit that stores the obtained values and a high-speed Fourier transform that performs high-speed Fourier transform based on the sampling values.
Included in the telemetry data processing unit, the spectrum value storage unit that stores the spectrum values obtained by the high-speed Fourier transform, the transmission unit that processes the transmission of the spectrum values as telemeter data, and the telemeter data. It is characterized in that a waveform reproduction processing section for reproducing the analog signal waveform based on the spectrum value is provided.

[0011]

1 is a block diagram showing an embodiment of the present invention. At the slave station 10, the voltage and current at the time of a power system fault are input as analog signal waveform data, and the A / D change section 11
Data conversion from an analog value to a digital value is performed via. Reference numeral 12 denotes a microcomputer that constitutes a sampling processing unit, a sampling value storage unit, and a spectrum value storage unit.

As is well known, the microcomputer 12 includes a central processing unit 12A and a ROM 12B containing a program for operating the central processing unit 12A in a predetermined order.
RAM12C for temporarily storing data, and input port 12
D, and an output port 12E. Input port
Fault voltage and current data from the A / D converter 11 are input to the 12D as digital signals. Here, the value of the digital signal is processed in accordance with a sampling program having a preset sampling period and stored in the RAM 12C.

Therefore, the central processing unit 12A and the ROM 12B
Is a sampling processing unit, and the RAM 12C is a sampling value storage unit. The sampling value stored in the RAM 12C is again processed by the central processing unit 12A according to the program stored in the ROM 12B, and the high-speed Fourier transform processing unit for performing the high-speed Fourier transform via the output port 12E.
Output to 13.

The high-speed Fourier transform processing unit 13 discretely processes the sampled values of the fault voltage and current, thereby capturing the original analog signal waveform as a superposition of waves of integral multiples of the fundamental frequency, A spectrum value corresponding to the amplitude of each frequency is calculated. The above spectral values are
It is input via the input port 12D and stored in the RAM 12C. Therefore, the RAM 12C constitutes a spectrum value storage unit.

The spectrum values of the analog signal waveforms of the fault voltage and current obtained by the above configuration are output port 12E.
The data is output to the transmission unit 14 for transmitting and processing the telemeter data via the, and transmitted to the master station 20.

In the master station 20, the transmission section 21 receives and processes the telemeter data transmitted from the slave station 10. The sampled value obtained as a result is a waveform reproduction processing unit that reproduces the analog signal waveform of voltage and current in the event of a power system failure.
Input to 22. The accident waveform reproduced by the waveform reproduction processing unit 22 can be output on a CRT or the like for accident analysis in a supervisory control system using a computer, for example.

Next, the operation of the supervisory control system configured as described above will be described with reference to FIG. 2 for improving the efficiency of transmission of voltage and current analog signal waveforms at the time of an accident.

It is assumed that the waveform of FIG. 2A is an example of voltage and current waveforms at the time of an accident. (In reality, the waveform has various shapes, but this waveform is assumed as an extreme example to simplify the explanation.)

The analog signal waveform at the time of an accident, which is input through the A / D converter, is read as a digital signal at a preset sampling cycle t ₁ second by the sampling processor, and the result is stored in the sampling value storage unit. Is stored. If sampling is performed for T seconds, a total of N = T / t ₁ (pieces) of data is stored in the sampling value memory.
Data will be stored.

Next, based on the above N data, the high-speed Fourier transform processing section performs high-speed Fourier transform to oscillate from 0 times to N / 2-1 times in T seconds. The spectral value corresponding to the amplitude value of each of the N / 2 waves can be determined.

Naturally, the total number of spectrum values becomes N / 2, and theoretically, even with the processing up to this point, the amount of transmission data from the slave station to the master station necessary for reproducing the analog waveform can be reduced to half. Now, the analog signal waveform obtained based on the above processing is the waveform as shown in FIG.

[0022]

[Equation 1] In the case where it can be sufficiently approximated by, the number of spectrum values required for reproducing the analog waveform is 5, which is an extremely small amount of data.

2 (b), (c), (d),
The waveforms shown in (e) and (f) become the fundamental waves for approximating the waveform shown in (a), and are a ₁ , a ₂ , a ₃ , a ₄ , a ₅
Is the amplitude value for each amplitude number, that is, the spectrum value.

There are various cases depending on the system as to how much the approximate waveform can be reproduced, but it is sufficiently small if the characteristics of the fault voltage and current waveforms in the system are understood to some extent in advance. It can be said that waveform reproduction is possible with the amount of transmission data. Further, with reference to FIG. 3, description will be given based on the transfer of data between the slave station and the master station.

FIG. 3 shows an example of format when HDLC transmission is used. FIG _{2 a 1, a 2, a} 3, a 4, a 5 each spectral value for approximating the waveform shown by (b) the information Fi - predefined follower in field -
Stored in matte.

The master station 20, which has received the data format from the slave station 10, grasps the characteristics of the waveform in advance. In the case of this example, in order to reproduce the waveform shown in FIG. 2A, the constants k ₁ , k ₂ , k ₃ , k ₄ and k ₅ in the characteristic equations that the master station 20 itself grasps are set _{to the a 1} , A ₂ , a
_The waveforms are approximated with the values of ₃ , a ₄ and a ₅ .

[0027]

[Equation 2] Is the final waveform approximation formula.

In the master station 20, the fault voltage and current data are drawn as analog signal waveforms on the CRT, for example, based on the above final equation, and the cause of the fault is analyzed.

[0029]

As described above, according to the present invention, the high-speed Fourier transform is used in the reproduction of the voltage / current analog signal waveform at the time of an accident in which a large amount of transmission data is required. The transmission data can be reduced by obtaining the spectrum value of the waveform and transmitting the spectrum value.

If further approximation is possible,
It is possible to provide a supervisory control system that enables the reproduction of the above waveform with a significantly small amount of transmission data and facilitates analysis in the event of an accident.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention,

FIG. 2 is a diagram showing an example of fault voltage / current analog signal waveforms for supplementary explanation of the operation of the embodiment of the present invention;

FIG. 3 is a data transmission packet between a slave station and a master station according to the present invention.
Matt example.

[Explanation of symbols]

 11 ... A / D converter, 12 ... Microcomputer 12A ... CPU, 12B ... ROM 12C ... RAM, 12D ... Input port 12E ... Output port, 13 ... High-speed Fourier transform processing unit 14, 21 … Transmission unit, 22… Waveform playback processing unit

Claims (4)

[Claims] 1. A supervisory control system for supervising and controlling a controlled device by transmitting information required for monitoring and control between a control station (master station) and a controlled station (slave station). Then, an A / D conversion unit that converts an analog signal waveform that is input from analog to digital, a sampling processing unit that samples the data after A / D conversion according to a preset sampling cycle, and the sampling value The master station is equipped with a high-speed Fourier transform processing unit that performs high-speed Fourier transform based on the above, and a transmission unit that performs transmission processing of the spectrum value obtained by the high-speed Fourier transform as telemeter data. The transmission unit that receives and processes the telemeter data transmitted from the station, and the waveform replay that reproduces the analog signal waveform based on the spectrum value contained in the telemeter data. A supervisory control system comprising a raw processing section. 2. A supervisory control system for supervising and controlling a controlled device by transmitting information required for monitoring and control between a control station (master station) and a controlled station (slave station). Then, an A / D conversion unit that converts the analog signal waveform that is input from analog to digital, a sampling processing unit that samples the data after A / D conversion according to a preset sampling period, and A sampling value storage unit that stores the values, a high-speed Fourier transform processing unit that performs a high-speed Fourier transform based on the sampling values, and a spectrum value storage unit that stores the spectrum values obtained by the high-speed Fourier transform. , A transmission unit for transmitting and processing the spectrum value as telemeter data, and the master station for receiving and processing the telemeter data transmitted from the slave station. A transmission unit, telemetry - Polygonum - monitoring and control system based on the spectral values contained in data, characterized by comprising a waveform reproduction section for reproducing the analog signal waveform. 3. The monitoring control system according to claim 1, wherein the sampling processing unit, the sampling value storage unit, and the spectrum value storage unit are constituted by a microcomputer. 4. The supervisory control system according to claim 2, wherein each constant of the waveform approximation formula in the high-speed Fourier transform processing unit is made equal to the constant of the waveform approximation formula in the waveform reproduction processing unit.