KR100650956B1 - Apparatus for processing electrical signal for automation of electricity delivery - Google Patents

Abstract

An electric signal processing apparatus for automatic power distribution is provided to reduce probability of error generation of an operation clock or a sampling clock of an A/D converter, by providing a GPS clock to the A/D converter as a reference clock. A sensor part(300) comprises a plurality of sensors, and outputs a plurality of sensing signals by sensing an electric signal. A filter part(310) comprises a plurality of filters, and filters a high frequency signal from each sensing signal outputted from the sensor part. A multiplexing part(320) performs switching according to a switching period, and outputs one of the filtered signals selectively. An A/D converter part(340) converts an analog signal from the multiplexing part into sampling data of a digital signal according to a sampling period. A buffer(350) stores sampling data of the digital signal converted by the A/D converter part. An FFT(Fast Fourier Transform) processing part(360) performs FFT processing of the sampling data stored in the buffer. And a data conversion part(370) converts the data processed in the FFT processing part into data capable of judging whether the electric signal is abnormal or not.

Description

Apparatus for processing electrical signal for automation of electricity delivery

1 is a block diagram showing an electric signal processing apparatus for a conventional distribution automation.

2 is a diagram for explaining a relationship between a first period and a second period of an electrical signal;

Figure 3 is a block diagram showing an electric signal processing apparatus for distribution automation of the present invention.

4 is a diagram for explaining a position where sampling data is formed in an electric signal;

5 is a diagram illustrating an embodiment of sampling data input to be processed by an FFT processor.

FIG. 6 is a diagram for explaining regions of sampling data subjected to FFT processing in a plurality of FFT processing units. FIG.

* Description of the symbols for the main parts of the drawings *

300 sensor unit 310 filter unit

320: multiplexer 330: reference clock provider

331: GPS receiver 333: GPS clock extractor

335: clock providing unit 340: A / D converter

350: buffer 360: FFT processing unit

370: data conversion unit 380: air interface means

390: control unit

The present invention relates to an electrical signal processing apparatus for distribution automation, wherein the generation of data capable of determining whether there is an abnormality of an electrical signal input from a substation or the like, the electrical signal processing for distribution automation to prevent delay Relates to a device.

The distribution automation system uses a computer installed in the central control room to monitor and control the switchgear for distribution lines located in remote areas, measure voltage and current, and automatically check the fault section in the event of a failure. It is a system that performs grid operation remotely. In other words, it is a system that checks the condition of the line through the monitor and automatically detects the occurrence section when a failure occurs, so that the recovery time can be shortened by remotely blocking only the failure section and performing a quick recovery.

Due to the advantages of the system, the distribution automation system is widely used to improve the inconvenience of delayed recovery time. The distribution automation system receives an electrical signal from a substation or the like for the electrical signal processing apparatus for distribution automation, converts the data into data capable of determining whether there is an abnormality of the electrical signal, and outputs the converted signal.

However, in the conventional electrical signal processing apparatus for distribution automation, there is a problem such as a delay in deriving data to determine the abnormality of the electrical signal.

1 is a block diagram showing a conventional electrical signal processing apparatus for distribution automation. As shown in the drawing, a conventional electrical signal processing apparatus for power distribution automation includes a sensor unit 100, a filter unit 110, an A / D converter unit 120, and a multiplexer (MUX: Multiplexer) ( 130, a signal processor 140, a data converter 150, and a controller 160.

The sensor unit 100 is composed of a plurality of current sensors or voltage sensors. The sensor unit 100 receives an electrical signal from a substation, and outputs a sensing signal by sensing the received electrical signal with a current sensor or a voltage sensor.

The filter unit 110 removes the high frequency component by filtering the sensing signal of the sensor unit 100. The filter unit 110 is composed of the same number of filters as the sensors constituting the sensor unit 100.

The A / D converter 120 converts a plurality of analog signals output from the filter unit 110 into digital signals. The A / D converter 120 is composed of the same number of A / D converters as the number of filters constituting the filter unit 110, each A / D converter receives a signal output from each filter is digital Convert to a signal. The A / D converter samples the analog signal output from the filter unit 110 in a specific sampling period and converts the analog signal into sampling data of the digital signal.

The multiplexer 130 receives sampling data of a plurality of digital signals converted by the A / D converter 120 to selectively output sampling data of one digital signal. The multiplexer 130 receives outputs of a plurality of A / D converters constituting the A / D converter 120. The multiplexer 130 switches the sampling data of the digital signal converted by one A / D converter by switching at a specific switching cycle under the control of the controller 160. The switching period of the multiplexer 130 is the same as the period of the electrical signal.

The signal processor 140 receives the sampling data of the digital signal output from the multiplexer 130 and processes the fast fourier transform (FFT). The signal processor 140 performs FFT processing on the sampling data output from the multiplexer 130 using a general-purpose digital signal processor (DSP) module.

The data converter 150 converts the data processed by the signal processor 140 into data capable of determining whether an electrical signal is abnormal.

The controller 160 controls the multiplexer 130 and the signal processor 140. The conventional electrical signal processing apparatus for power distribution automation includes sampling data of digital signals converted by another A / D converter after FFT processing for sampling data of digital signals converted by one A / D converter is completed. FFT processing for the For example, the multiplexer 130 outputs sampling data of the digital signal converted by the first A / D converter, and the signal processor 140 performs FFT processing on the output sampling data. The sampling data subjected to the FFT processing are sampling data for the first period of the electric signal. After the FFT processing ends, the multiplexer 130 switches to output sampling data of the digital signal converted by the second A / D converter, and the signal processor 140 performs FFT processing on the sampling data. Do The sampling data subjected to the FFT processing are sampling data for a second period of the electric signal. FIG. 2 is a diagram for describing a relationship between a first period and a second period of the electrical signal, wherein sampling data of the second period is slower by one period than sampling data of the first period. After repeating the above process and performing FFT processing on the sampling data of the digital signal converted by the MA / D converter, the multiplexer 130 switches to the first A / D converter to sample the converted digital signal. FFT the data. As such, the controller 160 controls the multiplexer 130 to selectively output sampling data of the digital signal converted by one A / D converter at a specific time point. In addition, the controller 160 controls the signal output from the multiplexer 130 to be FFT-processed at the specific time point.

In the case of using the conventional electrical signal processing apparatus for power distribution automation, after the FFT processing for the sampling data of the digital signal converted in one A / D converter is finished, the other A / D converter FFT processing is performed by outputting sampling data of the converted digital signal. Because of this, it is difficult to determine the abnormality of the electrical state through real-time monitoring. That is, a delay is generated by the time required for the FFT processing of the sampling data by the signal processor.

In order to solve the problem caused by the delay in time, there is a method using a plurality of general-purpose DSP module, or a general-purpose DSP module with a very high processing speed. However, when the above method is used, there is a problem that the price increases and the mounting space increases.

In addition, the use of the general-purpose DSP module, the control unit 390 (160) and the plurality of A / D converters requires a large mounting space. As a result, the area of the electrical signal processing device for distribution automation is increased, so that the clock supply to the A / D converter by the mounted oscillator can escape precise synchronization. That is, there is a problem that each A / D converter can operate with a different clock.

Therefore, it is an object of the present invention to convert an electrical signal input from a substation into sampling data of a digital signal, and to convert it into data capable of determining an abnormality of the electrical signal by performing FFT processing, with no delay in distribution. It is to provide an electrical signal processing device for automation.

In addition, another object of the present invention is to provide an electrical signal processing apparatus for power distribution automation that prevents an increase in price and reduces mounting space by not using a general-purpose DSP module.

Another object of the present invention is to provide a GPS clock as a reference clock to an A / D converter using a GPS receiver, so that the operation clock or sampling clock of the A / D converter has a low probability of error. To provide a processing device.

Electrical signal processing apparatus for power distribution automation of the present invention for achieving this purpose is composed of a plurality of sensors, the sensor unit for sensing the electrical signal and outputs a plurality of sensing signals, and a plurality of filters, the sensor unit A filter unit for filtering a high frequency signal from each of the plurality of output sensing signals, a multiplexing unit for selectively outputting only one signal among a plurality of signals filtered by the filter unit by switching according to a switching period; An A / D converter for sampling the analog signal outputted from the multiplexer according to a sampling period and converting it into sampling data of a digital signal; and receiving a GPS signal and providing a GPS clock as a reference clock value to the A / D converter. A reference clock providing unit, a buffer for storing sampling data of the digital signal converted by the A / D converter unit, and storing in the buffer A plurality of FFT processing unit for FFT processing the sampling data, a data conversion unit for converting the data processed by the FFT processing unit to the data that can determine the abnormality of the electrical signal, and transmitting the data converted by the data conversion unit Characterized in that the air interface means.

The reference clock providing unit receives a GPS signal, a GPS clock extractor extracting a GPS clock from a GPS signal received by the GPS receiver, and a GPS clock extracted by the GPS clock extractor based on the A / D converter. It is characterized by consisting of a clock providing unit for providing a clock.

The air interface means is any one of Bluetooth, Wi-Fi (WiFi) and UWB communication module.

The sensor may be a current sensor or a voltage sensor.

The switching period is characterized in that the same as the sampling period.

The buffer may be a buffer having a size capable of storing sampling data of a digital signal in which one electric signal is converted in accordance with the sampling period in the A / D converter.

The buffer is an electrical signal processing apparatus for distribution automation, characterized in that for forming and storing the sampling data for the signal filtered by the filter in a group (Group).

During the time that the FFT processor performs FFT processing of the sampling data, the buffer deletes one sampling data stored first in time and receives and stores one sampling data from the A / D converter.

Each of the plurality of FFT processing units may perform FFT processing on sampling data of each group, using sampling data of a signal filtered by one filter among sampling data stored in the buffer as one group.

The order in which each of the plurality of FFT processing units performs FFT processing on the sampling data of each group is characterized by preferentially processing the sampling data of the group including the sampling data stored first in the buffer in time.

Hereinafter, an electric signal processing apparatus for distribution automation of the present invention will be described in detail with reference to the drawings.

3 is a block diagram showing an electric signal processing apparatus for distribution automation of the present invention. As shown in the drawing, the electrical signal processing apparatus for distribution automation includes a sensor unit 300, a filter unit 310, a multiplexer 320, a reference clock provider 330, and an A / D converter unit. 340, a buffer 350, a plurality of FFT processing units 360, a data converter 370, a wireless interface means 380, and a control unit 390.

The sensor unit 300 is composed of a plurality of current sensors or voltage sensors. The sensor unit 300 receives an electrical signal from a substation, and outputs a sensing signal by sensing the received electrical signal with a current sensor or a voltage sensor.

The filter unit 310 includes a plurality of filters, and filters the high frequency signals from the plurality of sensing signals output from the sensor unit 300. Since the sensing signal output from the sensor unit 300 may be affected by noise, the filter unit 310 may reduce the influence of noise by removing the high frequency component.

The multiplexer 320 switches according to a switching cycle, and selectively outputs only one signal among a plurality of signals filtered by the filter 310. The multiplexer 320 sequentially outputs the signal filtered by the first filter of the filter 310 to the signal filtered by the Mth filter. After the multiplexer 320 outputs the signal filtered by the Mth filter, the multiplexer 320 switches back to the first filter and sequentially outputs the signal filtered by the first filter to the signal filtered by the Mth filter. However, the signal output by the multiplexer 320 is not necessarily limited to output from the signal filtered by the first filter to the signal filtered by the Mth filter. However, when the multiplexer 320 outputs a signal, the signal filtered by the first filter should not be output after the first filter to the signal filtered by the M-1 filter. That is, after outputting the signal filtered by all the filters from the first filter to the signal filtered by the M-th filter, the signal filtered by the first filter should be output again. In this case, the signal output from the former first filter is faster than the signal output from the latter first filter by one period of the electric signal.

The reference clock providing unit 330 receives a global positioning system (GPS) signal, extracts a GPS clock, and provides the extracted GPS clock to the A / D converter 340 as a reference clock. The GPS clock is a clock that can be extracted from the GPS signal and is an accurate clock close to 0%. In the reference clock providing unit 330, the GPS receiver 331 receives a GPS signal, and the GPS clock extractor 333 extracts a GPS clock from the GPS signal received by the GPS receiver 331. The extracted GPS clock is stabilized in a clock providing unit 335 including a phase locked loop (PLL) or delay locked loop (DLL) and provided to the A / D converter 340 as a reference clock.

The A / D converter 340 samples the analog signal output from the multiplexer 320 according to a sampling period and converts the analog signal into a digital signal. That is, the A / D converter 340 samples the analog signal in the same sampling period as the switching period and converts the analog signal into sampling data of the digital signal. The A / D converter 340 receives a reference clock from the reference clock provider 330. The A / D converter 340 compensates the operation clock value with the input reference clock, thereby reducing the probability of error occurrence. Alternatively, the A / D converter 340 compensates the sampling period with the reference clock, thereby reducing the probability of error occurrence.

4 is a diagram for describing a position where sampling data is formed in an electrical signal. As shown, the number located to the right of the two numbers described in the sampling data indicates the number of the filter filtering the signal used to generate the sampling data. The number on the left indicates whether the signal is used to generate sampling data among the signals filtered by each filter during one cycle time of the electrical signal and output through the multiplexer. That is, when the number described in the sampling data is (1, 3), this means that the sampling data is filtered by the third filter, and is filtered by the third filter during one cycle time of the electrical signal and outputted through the multiplexer. It means that the sampling data for the signal used as. If the number described in the sampling data is (2,4), this is the second of the signals that are filtered by the fourth filter and filtered by the fourth filter for a period of one period of the electrical signal and output through the multiplexer. Means sampling data for the signal used.

In the figure, the electric signal indicates an electric signal with respect to a subordinated time in time as it progresses to the right. The multiplexer switches according to a switching period and outputs a signal filtered by each filter. In the drawing, signals filtered by each filter from the first to fourth filters are sequentially output to generate sampling data. Indicates that it is used. After the fourth filter is filtered and output the signal is used to generate the sampling data, the first filter is filtered again to indicate that the output signal is used to generate the sampling data. The above process is repeated over and over. Sampling data for the first signal used among the signals filtered by each filter and output through the multiplexer is formed during one period of the electric signal, and then sampling data for the second and third used signals. Indicates that is generated.

The buffer 350 stores sampling data of the digital signal converted by the A / D converter 340. The buffer 350 is a buffer 350 having a size capable of storing sampling data of a digital signal in which an electric signal of one cycle is converted in accordance with the sampling period in the A / D converter 340. For example, if one electric signal is composed of 42 pieces of sampling data by the sampling period of the A / D converter 340, the size of the buffer 350 is at least large enough to store the 42 pieces of sampling data. Should be However, in order to prevent waste of the buffer 350, the buffer 350 should be large enough to store 42 sampling data. The storage areas of the buffer 350 are initially set to all zero values. That is, the buffer initially stores a default value of 0 in the storage area.

The FFT processor 360 performs FFT processing on the sampling data stored in the buffer 350. Each of the plurality of FFT processing units 360 performs FFT processing on sampling data of each group by using sampling data of a signal filtered by one filter among sampling data stored in the buffer 350 as one group. 5 is a diagram illustrating an embodiment of sampling data input to be processed by an FFT processor. Two numbers described in the sampling data in FIG. 5 are the same as those described with reference to FIG. 4. As shown, the sampling data stored in the buffer 350 is formed of one group of sampling data for the signal filtered by one filter. As a method of forming a group of sampling data in the buffer, there are various methods such as setting a location where each sampling data is stored in the buffer under the control of the controller 390. That is, the sampling data of the first to Nth signals among the signals filtered by the first filter and output through the multiplexer 320 for one period of the electric signal are stored in a group. . The same applies to sampling data for a signal filtered by the second filter. These groups are formed up to sampling data for the signal filtered by the Mth filter. The sampling data constituting each of the formed groups is subjected to FFT processing in a corresponding FFT processing unit.

However, in the order in which the FFT processor 360 performs FFT processing on the sampling data of each group, the sampling data of the group including the sampling data stored first in time in the buffer 350 is preferentially processed. That is, in the case of the drawing, sampling data of a group containing sampling data of (1, 1) is processed first, and then including the sampling data in the order of (1, 2), (1, 3). Processing is performed in order of sampling data of a group. The time point at which the plurality of FFT processing units are operated is controlled by the controller 390.

During the time when the FFT processor 360 performs FFT processing of the sampling data, the buffer 350 deletes one sampling data stored first in time, and receives and stores one sampling data from the A / D converter. . That is, in FIG. 5, sampling data of a group including sampling data of (1, 1) is first FFTed by the first FFT processor. Sampling data of (1, 1), which is one sampling data stored first in the buffer 350, is deleted during the time that the first FFT processing unit performs FFT processing. Then, one sampling data is input from the A / D converter. The received sampling data is sampling data of (1, 1) in which a period of an electric signal is slower than the deleted sampling data. This means that when the buffer 350 receives sampling data from the A / D converter 340, the signal filtered by the first filter is output through the multiplexer 320 due to the switching of the multiplexer 320. This is because it is just after the input point to the / D converter 340. The signal output through the multiplexer 320 is the first signal used in the electrical signal of one week to generate sampling data of the digital signal in the A / D converter. Therefore, the buffer 350 receives the sampling data of (1, 1).

After the sampling data of (1, 1) is deleted, the sampling data of the group including (1, 2), which is the first stored sampling data in time in the buffer 350, is FFTed by the second FFT processor. The sampling data of (1, 2), which is one sampling data stored first in the buffer 350, is deleted during the FFT processing in the second FFT processing unit. Then, the buffer 350 receives (1, 2) sampling data of the next period of the deleted sampling data.

However, when one or more default values are stored in the buffer 350, the data deleted from the buffer 350 may have a default value present at a location where sampling data input from the A / D converter unit 340 should be stored. It is deleted.

6 is a diagram for describing an area of sampling data subjected to FFT processing in a plurality of FFT processing units. As shown, FFT processing is performed from sampling data of (1,1) to sampling data area of (3,1), and then FFT from sampling data of (1,2) to sampling data area of (3,2). Processing. In this way, the sampling data area subjected to the FFT process is sliding in the order of time. Of course, not all the sampling data existing in the region subjected to the FFT processing is subjected to the FFT processing, but the FFT processing of only the sampling data of a specific portion has no influence on the data that can determine the abnormality of the electrical signal.

The data converter 370 converts the data processed by the plurality of FFT processors 360 into data capable of determining whether an electrical signal is abnormal. The data capable of determining whether there is an abnormality of the electrical signal is, for example, data on power factor of the electrical signal.

The air interface means 380 transmits data for determining whether an electrical signal converted by the data converter 370 is abnormal. The air interface means 380 is composed of any one of Bluetooth, Wi-Fi (WiFi), and Ultra Wideband (UWB) communication module, and the transmitted data is inputted to a computer installed in a central control room to determine whether current electricity is supplied without abnormality. It becomes judgment data.

The controller 390 controls the real time monitoring to determine whether there is an abnormality of the electrical signal. That is, the controller 390 controls the switching cycle of the multiplexer 320 and the sampling cycle of the A / D converter 340. In addition, the sampling data is controlled to form a group in the buffer, and an operation time point of each of the plurality of FFT processing units is controlled.

On the other hand, while the present invention has been shown and described with respect to specific preferred embodiments, various modifications and changes of the present invention without departing from the spirit or field of the invention provided by the claims below It can be easily understood by those skilled in the art.

As described above, the present invention makes it possible to prevent a delay in generating data capable of determining whether an electrical signal inputted from a substation or the like is abnormal. In addition, there is an economical cost in implementing the electric signal processing apparatus, and does not require a large mounting space. In addition, the probability of error occurrence of the operating clock or sampling clock of the A / D converter is low.

Claims (13)

A sensor unit configured of a plurality of sensors, the sensor unit configured to sense an electrical signal and output a plurality of sensing signals; A filter unit including a plurality of filters and filtering high frequency signals from the plurality of sensing signals output from the sensor unit; A multiplexer which switches according to a switching period and selectively outputs only one signal among a plurality of signals filtered by the filter unit; An A / D converter for converting the analog signal output from the multiplexer into sampling data of a digital signal according to a sampling period; A buffer for storing sampling data of the digital signal converted by the A / D converter; An FFT processor configured to process fast fourier transform (FFT) on the sampling data stored in the buffer; And A data converter converting the data processed by the FFT processor into data capable of determining an abnormality of an electrical signal; Electrical signal processing device for distribution automation. The method of claim 1, Receiving a GPS signal to extract a GPS clock from the received GPS signal, and further comprising a reference clock providing unit for providing a reference clock to the A / D converter unit, And the A / D converter compensates for an operation clock in accordance with a reference clock provided by the reference clock providing unit. The method of claim 1, Receiving a GPS signal to extract a GPS clock from the received GPS signal, and further comprising a reference clock providing unit for providing a reference clock to the A / D converter unit, And the A / D converter compensates for the sampling period according to the reference clock provided by the reference clock providing unit. The apparatus of claim 2 or 3, wherein the reference clock providing unit; A GPS receiver for receiving a GPS signal; A GPS clock extractor configured to extract a GPS clock from a GPS signal received by the GPS receiver; And A clock providing unit providing the GPS clock extracted by the GPS clock extracting unit to the A / D converter as a reference clock; Electrical signal processing apparatus for distribution automation, characterized in that configured. The method of claim 1, And an air interface means for transmitting the data converted by the data conversion unit. The method of claim 5, The air interface means is an electrical signal processing device for distribution automation, characterized in that any one of Bluetooth, Wi-Fi (WiFi) and UWB communication module. The method according to any one of claims 1 to 3, The sensor is an electrical signal processing device for power distribution automation, characterized in that the current sensor or a voltage sensor. The method according to any one of claims 1 to 3, The switching period is the electrical signal processing apparatus for power distribution automation, characterized in that the same as the sampling period. The method according to any one of claims 1 to 3, The buffer is an electrical signal processing device for distribution automation, characterized in that the buffer of the size that can store the sampling data of the digital signal converted by the electrical signal of one cycle in the A / D converter according to the sampling period. The method according to any one of claims 1 to 3, The buffer is an electrical signal processing apparatus for distribution automation, characterized in that for forming and storing the sampling data for the signal filtered by the filter in a group (Group). The method according to any one of claims 1 to 3, During the time that the FFT processor performs the FFT processing of the sampling data, the buffer deletes one sampling data stored first in time and receives and stores one sampling data from the A / D converter. Electrical signal processing apparatus for. The method according to any one of claims 1 to 3, The FFT processing unit includes a plurality, and each of the plurality of FFT processing units performs FFT processing on sampling data of each group by using sampling data of a signal filtered by one filter among sampling data stored in the buffer as a group. Electrical signal processing device for distribution automation. The method of claim 12, The order in which each of the plurality of FFT processing units performs the FFT processing on the sampling data of each group may be performed by processing the sampling data of the group including the sampling data stored first in the buffer in time in advance. Signal generator.

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