JP5579087B2 - Protective relay device - Google Patents

Description

  The present invention relates to a protective relay device that protects a power system (hereinafter referred to as “system”).

  In the conventional general protective relay device, the input electric quantity detected in the system is sampled at a predetermined sampling frequency, and digital filter processing (filter processing) is sequentially performed using the digitized data. Relay calculation is performed at a different frequency (calculation frequency). The reason why the calculation frequency is different from the sampling frequency is that the sampling frequency is increased for the purpose of simplifying the analog filter, and the calculation frequency is a low frequency from the viewpoint of the usefulness of hardware.

  For example, in the conventional protective relay device shown in Patent Document 1 below, in order to suppress high frequency noise due to the sampling theorem, an arbitrary overlap period is set according to the output interval of digital data digitized at a predetermined sampling frequency. Filter processing is executed while holding it. Digital information for relay calculation is obtained by this filtering process. In this protective relay device, an addition type filter is used as a digital filter. Digital data is generated at a sampling frequency higher than the calculation frequency, and filter processing is executed using this digital data.

  On the other hand, Patent Document 2 below describes that digital filter processing causes a time delay (phase delay) of relay operation.

JP 2003-274548 A (paragraph 0017-0020, paragraph 0028, paragraph 0032-0033, FIG. 1) JP-A-8-19161 (paragraph 0004)

  Here, the protection relay device disclosed in Patent Document 1 adopts a sequential calculation method in which relay calculation is performed with the latest digital information every time digital information subjected to filter processing is acquired. Even when the error occurred, it was only processed as an operation time delay. On the other hand, in recent years, a protection relay device in which a sampling unit that performs digital conversion (sampling) and a relay operation unit are separated may be used due to progress of digital technology. In this protection relay device, for example, it is necessary to take measures such as ensuring the same time property of the sampling data and the relay calculation data by adding the time data at the time of sampling to the sampling data. However, in the conventional technology represented by the protective relay device disclosed in Patent Document 1, since such measures are not taken into consideration, when phase delay due to filtering occurs, the sampling data and the relay calculation data There was a problem that the same time property may be impaired.

  This invention is made in view of the above, Comprising: It aims at obtaining the protection relay apparatus which can ensure the same time property of sampling data and relay operation data.

In order to solve the above-described problems and achieve the object, the protective relay device protects the power system based on the amount of electricity detected in the power system, and samples the amount of electricity at a predetermined sampling period. A sampling unit that generates a plurality of sampling values and stores a sampling time representing a timing at which the sampling values are generated in association with each sampling value, and an up-to-date odd number of sampling times that are continuous in time series Using the time as the base point time, the sampling value sampled at the base point time and the sampling value before the base point time after subtracting 1 from the odd number are added to obtain filter data, and from the odd number the value obtained by multiplying the value obtained by dividing 1 by 2 subtracting the sampling period as the delay time, the base time Karako A filter unit that gives the sampling time the sampling time that was traced back by a delay time to the filter data; and a relay calculation unit that performs a relay operation using the sampling time and the filter data from the filter unit. Features.

  According to the present invention, the filtering process is performed using the sampling values converted at an odd number of sampling times that are continuous in time series, so that the same time property of the sampling data and the relay calculation data can be secured. There is an effect.

FIG. 1 is a diagram schematically illustrating a protective relay device according to first to third embodiments of the present invention. FIG. 2 is a diagram schematically illustrating data stored in the protective relay device according to the first embodiment of the present invention. FIG. 3 is a diagram for explaining the relationship between a plurality of sampling data shown in FIG. 2 and relay calculation data obtained by filtering them. FIG. 4 is a diagram schematically illustrating data stored in the protective relay device according to the second embodiment of the present invention. FIG. 5 is a diagram for explaining the relationship between the plurality of sampling data shown in FIG. 4 and the relay calculation data obtained by filtering them. FIG. 6 is a diagram schematically illustrating data stored in the protective relay device according to the third embodiment of the present invention. FIG. 7 is a diagram for explaining the relationship between a plurality of sampling data shown in FIG. 6 and relay calculation data obtained by filtering them. FIG. 8 is a diagram schematically illustrating data stored in the protective relay device according to the fourth embodiment of the present invention. FIG. 9 is a diagram for explaining the relationship between the plurality of sampling data shown in FIG. 8 and the relay calculation data obtained by filtering them. FIG. 10 is a diagram schematically illustrating the protective relay device according to the fifth embodiment of the present invention. FIG. 11 is a diagram schematically illustrating relay calculation data based on sampling data before correcting the phase error and relay calculation data based on sampling data after correcting the phase error.

  Embodiments of a protective relay device according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram schematically illustrating a protective relay device 10 according to first to third embodiments of the present invention. FIG. 2 is a diagram schematically illustrating data stored in the protective relay device 10 according to the first embodiment. A protection relay device 10 shown in FIG. 1 includes a sampling unit 2, a filter unit 4 that is a digital filter, and a relay operation unit 9 as main components.

  The sampling unit 2 samples a grid electricity quantity 1 detected by a current transformer (not shown) arranged in the grid at a predetermined sampling frequency (sampling period), and a plurality of digitized sampling data Xt0. ~ Xt0 ± n (n is an integer) is generated. The sampling data Xt0 to Xt0 ± n are stored in the sampling data storage area 12 in the sampling unit 2 and taken into the filter unit 4 through the transfer line 3. Time data t0 to t0 ± n (n is an integer) indicating the sampling timing of the sampling data Xt0 to Xt0 ± n are stored in the time data storage area 11 in the sampling unit 2.

  On the left side of FIG. 2, time data t0 to t0 ± n stored in the time data storage area 11 and sampling data Xt0 to Xt0 ± n stored in the sampling data storage area 12 are schematically shown. . For example, the sampling data Xt0-1 is data sampled at a timing one before the sampling data Xt0, and the sampling data Xt0 + 1 is data sampled at a timing one time after the sampling data Xt0. The interval between the time data t0 to t0 ± n represents a sampling period, and the sampling unit 2 includes a plurality of sampling data Xt0 to Xt0 ± n sampled in the sampling period, and a plurality of time data t0 to t0 ± n. Are stored in time series in association with each other.

  The filter unit 4 performs, for example, addition type filtering on the sampling data Xt0 to Xt0 ± n obtained from the sampling unit 2, and data after filtering (filter data) Xt1 to Xt1 ± n (n is an integer) ) Is generated. The filter data Xt1 to Xt1 ± n are stored in the filter data storage area 14, and the time data t1 to t1 ± n indicating the timing of the filter processing are stored in the time data storage area 13. The filter data Xt1 to Xt1 ± n and the time data t1 to t1 ± n are taken into the relay operation unit 9 through the transfer line 5.

  2, time data t1 to t1 ± n stored in the time data storage area 13 and filter data Xt1 to Xt1 ± n stored in the filter data storage area 14 are schematically shown. Yes. For example, the filter data Xt1 is data obtained by filtering the sampling data Xt0-4 to Xt0, and is stored in association with the time data t1. The filter data Xt1 + 4 is data obtained by filtering the sampling data Xt0 to Xt0 + 4, and is stored in association with the time data t1 + 4. The filter data Xt1 + 8 is data obtained by filtering the sampling data Xt0 + 4 to Xt0 + 8, and is stored in association with the time data t1 + 8. The filter data Xt1 + 12 is data obtained by filtering the sampling data Xt0 + 8 to Xt0 + 12, and is stored in association with the time data t1 + 12. As described above, the filter unit 4 stores a plurality of pieces of time data t1 to t1 ± n and a plurality of pieces of filter data Xt1 to Xt1 ± n in time series.

  Note that the filter data (for example, Xt1-1) other than the filter data Xt1, Xt1 + 4, Xt1 + 8, and Xt1 + 12 shown in the middle of FIG. 2 includes a plurality of sampling data (for example, Xt0-5 to Xt0) in the same manner as these filter data. -1) is stored in association with time data (for example, t1-1) as data obtained by filtering.

  The relay calculation unit 9 includes a calculation frequency processing unit 6 and a calculation unit 8, and the calculation frequency processing unit 6 performs a sampling frequency reduction process, and uses a calculation frequency (calculation cycle) obtained by the reduction process as a filter. Data (for example, Xt1-4, Xt1, Xt1 + 4, Xt1 + 8, and Xt1 + 12) is extracted and stored in the relay calculation data storage area 16 as relay calculation data Xt2 to Xt2 ± n. The “reduction processing” is data not used for relay calculation (for example, Xt1-1 to Xt1-3 shown in FIG. 2) from the filter data Xt1 to Xt1n stored in the filter unit 4 shown in FIG. Is a process of thinning out.

  Further, time data t2 to t2 ± n indicating the timing of sampling data Xt0 to Xt0 ± n are stored in the time data storage area 15. The time data t1 to t1 ± n stored in the time data storage area 15 and the relay calculation data Xt2 to Xt2 ± n stored in the relay calculation data storage area 16 are schematically shown on the right side of FIG. ing.

  In the calculation unit 8, the relay calculation is executed using the relay calculation data Xt <b> 2 to Xt <b> 2 ± n transmitted from the calculation frequency processing unit 6 through the transfer line 7.

  Next, the operation will be described. The grid electricity quantity 1 input to the sampling unit 2 is taken into the sampling unit 2, sampled at a predetermined sampling period, and transmitted to the filter unit 4 together with time data t0 to t0 ± n. In the filter unit 4, filter processing is performed by the calculation of the equations (1) and (2) using Xt 0 to Xt 0 ± n from the sampling unit 2.

  The amplitude correction coefficient Km shown in the equation (2) is a coefficient for correcting the amplitude of the data obtained by the filter calculation.

As apparent from the equation (1), the number of terms in the arithmetic expression of the filter unit 4 is an odd number, and the order k is an even number. For example, when the integer i is 2, the order k of the equation (1) is 4 and the number of terms is 5. Therefore, the equation (1) is expressed as Y (t) = {X (t) + X (t−1) + X (t−2) + X (t−3) + X (t−4)} / Km. According to this equation, the filter unit 4 uses the latest time of an odd number of sampling times that are continuous in time series as a base time (for example, time data t0), and a sampling value (for example, Xt0) sampled at this base time. , The sampling values before the consecutive base time obtained by subtracting 1 from the odd number (for example, t0-1 to t0-4) are added, the added data is corrected by the amplitude correction coefficient Km, and the filter data ( Xt1), and the sampling time at the time point (t0-2) retroactive by this delay time from the base time as a delay time obtained by multiplying the odd number by 1 and dividing by 2 by the sampling period Assigned to the filter data (Xt1).

  As a result, the same time as the time data t0-2 is given to the time data t2, and the arithmetic operation unit 8 executes a relay operation based on the relay operation data Xt2. By such an operation, even when the filter unit 4 and the calculation unit 8 are separately provided, it is possible to ensure the same time property of the sampling data Xt0 to Xt0-4 and the relay calculation data Xt2. It becomes possible.

  Next, the relationship between the sampling data Xt0 to Xt0-4 and the relay calculation data Xt2 will be specifically described with reference to FIG.

  FIG. 3 is a diagram for explaining the relationship between the plurality of sampling data Xt0 to Xt0-4 shown in FIG. 2 and the relay calculation data Xt2 obtained by filtering them. In FIG. 3, as an example, sampling data Xt0 to Xt0-4 in the case where the order k of the filter operation is 4 and the relay operation data Xt2 obtained by performing the filter operation with these data are expressed in vectors. Yes. The dotted line vector represents the relay calculation data Xt2, and the solid line vector represents the sampling data Xt0 to Xt0-4. As apparent from FIG. 3, the vector of the relay calculation data Xt2 overlaps the vector of the sampling data Xt0-2. That is, the time data t2 matches the time data t0-2. The protection relay device 10 according to the first embodiment is configured to give the sampling time of the time data t0-2 to the relay calculation data Xt2.

As described above, the protective relay device 10 according to the first embodiment generates a plurality of sampling values by sampling the grid electricity quantity 1 at a predetermined sampling period, and represents the timing at which the sampling values are generated. A sampling unit 2 that stores a sampling time in association with each sampling value, a sampling value sampled at the base time, with the latest time of an odd number of sampling times consecutive in time series as a base time, and the odd number The sampled data before the base time obtained by subtracting 1 from the number is added to obtain filter data, and a value obtained by multiplying the odd number by subtracting 1 and dividing by 2 by the sampling period is used as a delay time. A filter that adds the sampling time to the filter data at the point that is delayed by the delay time from the base time 4 and the relay operation unit 9 that performs the relay operation using the sampling time from the filter unit 4 and the filter data, the sampling data Xt0 to Xt0 even when the sampling frequency and the operation frequency are different. It is possible to ensure the same time property between ± n and the relay calculation data Xt2 to Xt2 ± n.

Embodiment 2. FIG.
In the first embodiment, the base time (for example, time data t0) of the filter calculation is the latest time, and the time (time data t0-2) that is a predetermined delay time from the latest time is used as the relay calculation data (for example, Xt2). However, in the second embodiment, a time that is back by a predetermined delay time from the time when the filter process is started is used as the base point of the filter operation, and the time of this base point is used as the relay operation data Xt2. By giving, it is comprised so that the same time property may be ensured. Hereinafter, although the structure of the protection relay apparatus 10 concerning Embodiment 2 is demonstrated concretely, the same code | symbol is attached | subjected to the same part as Embodiment 1, and the description is abbreviate | omitted here, About only a different part here State.

  FIG. 4 is a diagram schematically illustrating data stored in the protective relay device 10 according to the second embodiment of the present invention. The time data storage area 21, sampling data storage area 22, time data storage area 23, filter data storage area 24, time data storage area 25, and relay calculation data storage area 26 shown in FIG. Similarly, time data t0 to t0 ± n, sampling data Xt0 to Xt0 ± n, time data t1 to t1 ± n, filter data Xt1 to Xt1 ± n, time data t2 to t2 ± n, relays Calculation data Xt2 to Xt2 ± n are stored.

  Next, the operation will be described. The grid electricity quantity 1 input to the sampling unit 2 is taken into the sampling unit 2, sampled at a predetermined sampling period, and transmitted to the filter unit 4 together with time data t0 to t0 ± n. The filter unit 4 uses the Xt0 to Xt0 ± n from the sampling unit 2 to perform filter processing by the calculations of the equations (3) and (4).

  The amplitude correction coefficient Km shown in the equation (4) is a coefficient for correcting the amplitude of the data obtained by the filter calculation.

  As apparent from the equation (3), the number of terms in the arithmetic expression of the filter unit 4 is an odd number, and the order k is an even number. For example, when the integer i is 1, the degree k of the expression (3) is 2 and the number of terms is 5. Therefore, the expression (3) can be expressed as Y (t) = [X (t) + {X (t + 1) + X (t-1)} + {X (t + 2) + X (t-2)} / Km. According to this equation, the filter unit 4 is a value obtained by dividing a value obtained by subtracting 1 from the odd number from the latest time of an odd number of sampling times (for example, t0 + 2 to t0-2) that are continuous in time series. Sampling values (Xt0) sampled at the base time and sampling values (Xt0-1, Xt0-2) sampled at a predetermined time before the base time, with a time (t0) that is back by the time satisfying And the sampling value (Xt0 + 1, Xt0 + 2) sampled at a time paired with the predetermined time after the base time is obtained to obtain filter data (Xt1), and the base time (t0) is obtained as filter data (Xt1). To grant.

  As a result, the same time as the base time (time data t0-2) is given to the time data t2, and the arithmetic operation unit 8 executes the relay operation based on the relay operation data Xt2. By such an operation, even when the filter unit 4 and the calculation unit 8 are separately provided, it is possible to ensure the same time property of the sampling data Xt0 + 2 to Xt0-2 and the relay calculation data Xt2. It becomes possible.

  Next, the relationship between the sampling data Xt0 + 2 to Xt0-2 and the relay calculation data Xt2 will be specifically described with reference to FIG.

  FIG. 5 is a diagram for explaining the relationship between the plurality of sampling data Xt0 + 2 to Xt0-2 shown in FIG. 4 and the relay calculation data Xt2 obtained by filtering them. In FIG. 5, as an example, sampling data Xt0 + 2 to Xt0-2 when the order k of the filter operation is 2 and the relay operation data Xt2 obtained by performing the filter operation with these data are expressed in vectors. Yes. The dotted line vector represents the relay calculation data Xt2, and the solid line vector represents the sampling data Xt0 + 2 to Xt0-2. As is clear from FIG. 5, since the vector of the relay calculation data Xt2 overlaps the vector of the sampling data Xt0, the time data t2 matches the time data t0. The protection relay device 10 according to the second embodiment is configured to give the same time as the time data t0 to the relay calculation data Xt2.

  As described above, the protective relay device 10 according to the second embodiment samples the grid electricity quantity 1 at a predetermined sampling period to generate a plurality of sampling values, and represents the timing at which the sampling values are generated. Sampling unit 2 that stores sampling time in association with each sampling value, and satisfies the value obtained by dividing the value obtained by subtracting 1 from the odd number from the latest time of the odd number of sampling times that are consecutive in time series. A filter obtained by adding a sampling value sampled at a predetermined time before the base time and a sampling value sampled at a time paired with the predetermined time after the base time, with a time that is back by time as the base time Since the filter unit 4 that obtains the data and adds the base time to the filter data is provided, Even if the sampling frequency and the calculation frequency are different, it is possible to ensure the same time with the sampling data Xt0~Xt0 ± n and relay operation data Xt2~Xt2 ± n.

Embodiment 3 FIG.
In the first and second embodiments, the filter calculation is performed including sampling data at the base time, but in the third embodiment, the filter calculation is performed without using the sampling data at the base time. . The configuration of the protective relay device 10 according to the third embodiment will be specifically described below. The same parts as those in the first and second embodiments are denoted by the same reference numerals and the description thereof is omitted, and only different parts will be described here.

  FIG. 6 is a diagram schematically illustrating data stored in the protective relay device 10 according to the third embodiment of the present invention. In the time data storage area 31, the sampling data storage area 32, the time data storage area 33, the filter data storage area 34, the time data storage area 35, and the relay calculation data storage area 36 shown in FIG. t0 ± n, sampling data Xt0 to Xt0 ± n, time data t1 to t1 ± n, filter data Xt1 to Xt1 ± n, time data t2 to t2 ± n, and relay calculation data Xt2 to Xt2 ± n Is stored.

  Next, the operation will be described. The grid electricity quantity 1 input to the sampling unit 2 is taken into the sampling unit 2, sampled at a predetermined sampling period, and transmitted to the filter unit 4 together with time data t0 to t0 ± n. In the filter unit 4, filter processing is performed by the calculation of the equations (5) and (6) using Xt 0 to Xt 0 ± n from the sampling unit 2.

  The amplitude correction coefficient Km shown in the equation (6) is a coefficient for correcting the amplitude of the data obtained by the filter calculation.

  As is clear from the equation (5), the number of terms in the arithmetic expression of the filter unit 4 is an even number. For example, when the integer i is 1, the degree k of the equation (5) is 2 and the number of terms is 4. Therefore, the equation (5) can be expressed as Y (t) = [{X (t + 1) + X (t−1 )} + {X (t + 2) + X (t−2)} / Km. According to this equation, the filter unit 4 satisfies the sampling cycle * (the odd number-1) / 2 from the latest time of the odd number of sampling times (for example, t0 + 2 to t0-2) that are continuous in time series. The sampling time (Xt0-1, Xt0-2) sampled at a predetermined time before the base time and the predetermined time after the base time are sampled at a time that is a time point (t0) that is traced back as the base time. The sampling values (Xt0 + 1, Xt0 + 2) are added to obtain the filter data (Xt1), and the base time (t0) is given to the filter data (Xt1).

  As a result, the same time as the base time (time data t0-2) is given to the time data t2, and the arithmetic operation unit 8 executes the relay operation based on the relay operation data Xt2. By such an operation, even when the filter unit 4 and the calculation unit 8 are separately provided, it is possible to ensure the same time property of the sampling data Xt0 + 2 to Xt0-2 and the relay calculation data Xt2. It becomes possible.

  Next, the relationship between the sampling data Xt0 + 2 to Xt0-2 and the relay calculation data Xt2 will be specifically described with reference to FIG.

  FIG. 7 is a diagram for explaining the relationship between the plurality of sampling data Xt0 + 2 to Xt0-2 shown in FIG. 6 and the relay calculation data Xt2 obtained by filtering them. FIG. 7 shows, as an example, sampling data Xt0 + 2, Xt0 + 1, Xt0-1, Xt0-2 when the order k of the filter operation is 2, and relay operation data Xt2 obtained by filtering these data Is represented as a vector. The dotted line vector represents the relay calculation data Xt2, and the solid line vector represents the sampling data Xt0 + 2, Xt0 + 1, Xt0-1, and Xt0-2. Here, the vector of the relay calculation data Xt2 does not overlap any of the sampling data Xt0 + 2 to Xt0-2. However, in the protective relay device 10 according to the third embodiment, as described above, the time data The same time as the base time (time data t0-2) is given to t2.

  As described above, the protective relay device 10 according to the third embodiment generates a plurality of sampling values by sampling the grid electricity quantity 1 at a predetermined sampling period, and represents the timing at which the sampling values are generated. Sampling unit 2 that stores sampling time in association with each sampling value, and satisfies the value obtained by dividing the value obtained by subtracting 1 from the odd number from the latest time of the odd number of sampling times that are consecutive in time series. A filter obtained by adding a sampling value sampled at least at a predetermined time before the base time and a sampling value sampled at a time paired with the predetermined time after the base time, with a time that is traced back as a base time A filter unit 4 that obtains data and adds the base time to the filter data. Since manner was, even if the sampling frequency and the calculation frequency are different, it is possible to ensure the same time with the sampling data Xt0~Xt0 ± n and relay operation data Xt2~Xt2 ± n.

  In the protection relay device 10 according to the third embodiment, for example, even when there is no sampling data Xt0 at the base time, the sampling data Xt0-1, Xt0-2, Xt0 + 1, and Xt0 + 2 before and after the sampling data Xt0 are added. In addition, since the calculation data Xt2 can be obtained, the filter calculation can be simplified without reducing the relay calculation accuracy. For example, when an error occurs in predetermined sampling data (for example, Xt0), the filter operation may be temporarily interrupted when such error data occurs in the filter processing in a general protective relay device. However, since the protective relay device 10 according to the third embodiment can perform the filter operation except the error data, it is possible to improve the continuity of the relay operation.

Embodiment 4 FIG.
In the third embodiment, the filter operation is performed without using the sampling data (for example, Xt0) at the base time. However, in the fourth embodiment, data other than the sampling data at the base time is partially lost. Even in such a case, the filter operation can be continuously obtained. Hereinafter, although the structure of the protection relay apparatus 10 concerning Embodiment 4 is demonstrated concretely, the same code | symbol is attached | subjected to the same part as Embodiments 1-3, and the description is abbreviate | omitted here, and a different part Only about.

  FIG. 8 is a diagram schematically illustrating data stored in the protective relay device 10 according to the fourth embodiment of the present invention. The time data storage area 21, sampling data storage area 22, time data storage area 23, filter data storage area 24, time data storage area 25, and relay calculation data storage area 26 shown in FIG. t0 ± n, sampling data Xt0 to Xt0 ± n, time data t1 to t1 ± n, filter data Xt1 to Xt1 ± n, time data t2 to t2 ± n, and relay calculation data Xt2 to Xt2 ± n Is stored.

  Next, the operation will be described. The grid electricity quantity 1 input to the sampling unit 2 is taken into the sampling unit 2, sampled at a predetermined sampling period, and transmitted to the filter unit 4 together with time data t0 to t0 ± n.

  In the filter unit 4, filter processing is performed by the same arithmetic expression as the expressions (2) and (3) shown in the second embodiment. The number of terms in the arithmetic expression of the filter unit 4 according to the fourth embodiment is an odd number as in the second embodiment, and the order k is an even number. For example, when the integer i is 1, the degree k of the expression (3) is 2 and the number of terms is 5. Therefore, the expression (3) can be expressed as Y (t) = [X (t) + {X (t + 1) + X (t-1)} + {X (t + 2) + X (t-2)} / Km.

By Here, for example, errors in sampling, when the predetermined sampling data is lost, the filter unit 4, any of the sampled sampled value is missing in the base before time or time after the base time than In this case, the sampling value sampled at the time paired with this sampling value is excluded, the data not excluded is added, and the added data is corrected by the amplitude correction coefficient Km to obtain a filter calculation result. . The filter unit 4 satisfies a time satisfying a value obtained by dividing a value obtained by subtracting 1 from the odd number by 2 from the latest time (t0 + 2) of an odd number of sampling times (for example, t0 + 2 to t0-1) continuous in time series. as just back time base point time (t0), base time earlier or any missing base point time each sampling values sampled at a later time than (Xt0 + 2~Xt0-2) (in FIG. 8 Xt0-1 missing ), The sampling value paired with this sampling value (for example, Xt0 + 1) is excluded. The filter unit 4 pairs the sampling value (Xt0) sampled at the base time, the sampling value (Xt0-2) sampled before the base time, and the sampling value sampled after the base time. The obtained sampling value (Xt0 + 2) is added, and the added data is corrected by the amplitude correction coefficient Km to obtain the filter data (Xt1), and the base time (t0) is fetched from the sampling unit. And filter data are stored in association with each other.

  As a result, the same time as the base time (time data t0-2) is given to the time data t2, and the arithmetic operation unit 8 executes the relay operation based on the relay operation data Xt2. By such an operation, even when the filter unit 4 and the calculation unit 8 are separately provided, it is possible to ensure the same time property of the sampling data Xt0 + 2 to Xt0-2 and the relay calculation data Xt2. It becomes possible.

  Next, the relationship between the sampling data Xt0 + 2 to Xt0-2 and the relay calculation data Xt2 will be specifically described with reference to FIG.

  FIG. 9 is a diagram for explaining the relationship between the plurality of sampling data Xt0 + 2 to Xt0-2 shown in FIG. 8 and the relay calculation data Xt2 obtained by filtering them. In FIG. 9, as an example, sampling data Xt0 + 2 to Xt0-2 when the order k of the filter calculation is 2 and relay calculation data Xt2 obtained by filtering these data are represented in vector. . The solid line vector represents the sampling data Xt0 + 2 to Xt0-2. The dotted line vector overlapping the sampling data Xt0 vector represents the relay calculation data Xt2, and the dotted line vector written between the sampling data Xt0 vector and the sampling data Xt0-2 vector is the missing sampling data Xt0-1. Represents.

  Here, the filter unit 4 according to the fourth embodiment performs a filter operation by excluding the missing sampling data Xt0-1 and the sampling data Xt0 + 1 paired with the data. As a result of the calculation, relay calculation data Xt2 is obtained.

  Further, as is clear from FIG. 9, since the vector of the relay calculation data Xt2 overlaps the vector of the sampling data Xt0, the time data t2 coincides with the time data t0. The same time as the time data t0 is given to the relay calculation data Xt2.

  In addition, in the description of the operation of the filter unit 4 according to the fourth embodiment, the filter operation of the expression (3) shown in the second embodiment is used as an example, but the present invention is not limited to this. This can also be applied to the filter calculation of the equation (5) shown in the third embodiment.

As described above, in the protective relay device 10 according to the fourth embodiment, the filter unit 4 is a value obtained by subtracting 1 from the odd number from the latest time of the odd number of sampling times that are continuous in time series. Sampling sampled at a time paired with a sampling value sampled at a predetermined time before the base time and the predetermined time after the base time, with a time that is back by a time satisfying the value divided by 2 as the base time together determine the filter data by adding the values, since the base point time and to impart to the filter data, even if any of the sampled values after the base time earlier or than is missing, It is possible to ensure the same time property of the sampling data Xt0 to Xt0 ± n and the relay calculation data Xt2 to Xt2 ± n.

Embodiment 5 FIG.
In the first to fourth embodiments, the configuration example in the case where there is one sampling unit 2 and one filter unit 4 has been described. However, when there are a plurality of sampling units 2 and filter units 4, time data from one sampling unit 2 and There may be a phase error between the time data from the other sampling units 42. The protective relay device 10 according to the fifth embodiment is configured to solve such a problem.

  FIG. 10 is a diagram schematically illustrating the protective relay device 10 according to the fifth embodiment of the present invention. The sampling circuit 100 includes a sampling unit 2, the sampling circuit 101 includes a sampling unit 42 having a function equivalent to that of the sampling unit 2, and the data processing circuit 102 includes a plurality of filter units (for example, the filter unit 4 and the filter unit 44). ), A calculation frequency processing unit 6, and a calculation unit 8.

  For example, the sampling unit 2 samples the grid electricity quantity 1 detected by one current transformer (not shown) at a predetermined sampling period, and generates sampling data Xt0 to Xt0 ± n. Sampling data Xt0 to Xt0 ± n are taken into the filter unit 4 through the transfer line 3. The filter unit 4 performs addition type filter processing on the sampling data Xt0 to Xt0 ± n obtained from the sampling unit 2 to generate filter data Xt1 to Xt1 ± n (n is an integer).

  For example, the sampling unit 42 samples the grid electricity quantity 41 detected by another current transformer (not shown) at a predetermined sampling period, and generates sampling data Xt0 to Xt0 ± n. Sampling data Xt0 to Xt0 ± n are taken into the filter unit 44 through the transfer line 43. The filter unit 44 performs addition type filter processing on the sampling data Xt0 to Xt0 ± n obtained from the sampling unit 42 to generate filter data Xt1 to Xt1 ± n (n is an integer).

  The arithmetic frequency processing unit 6 performs a sampling frequency reduction process on the filter data Xt1 to Xt1 ± n from the filter unit 4. For example, Xt1-4, Xt1, Xt1 + 4, Xt1 + 8, and Xt1 + 12 shown in FIG. 2 are extracted at the calculation frequency obtained by this reduction process, and these data are converted into, for example, the relay calculation data Xt2-1 shown in FIG. , Xt2, Xt2 + 1, Xt2 + 2, and Xt2 + 3 are stored in the relay calculation data storage area 16.

  Here, time data t0 to t0 ± n from the sampling unit 2 (hereinafter referred to as “first time data”) and time data t0 to t0 ± n from the sampling unit 42 (hereinafter referred to as “second time data”). If a time difference greater than or equal to a predetermined value occurs, a process of correcting the first time data is performed. Hereinafter, this operation will be specifically described.

  FIG. 11 is a diagram schematically illustrating relay calculation data based on sampling data before correcting the phase error and relay calculation data based on sampling data after correcting the phase error. FIG. 11 shows a vector of each data shown in FIG. 2 as an example. The difference from FIG. 3 is that the phase error has occurred in the sampling data Xt0-3 (time data t0-3), so that the relay calculation data Xt2 (time data t2) is like a vector indicated by a one-dot chain line. This is a point that is shifted in a counterclockwise direction. In order to eliminate such a phase error of the time data t2, the filter unit 4 shown in FIG. 10, for example, among the five sampling data from Xt0 to Xt0-4) is the sampling data farthest in time series Xt0-4 or sampling data Xt0 is multiplied by an amplitude correction coefficient a. Hereinafter, this processing content will be described more specifically.

  The expression (7) is an arithmetic expression in which the content of the calculation is more specific than the expression (1), and is an expression for the filter operation executed by the filter unit 4 shown in FIG. The number of terms in equation (7) is an odd number, and the order k is an even number. For example, when the integer i is 2, the order k of the expression (7) is 4 and the number of terms is 5. Therefore, the expression (7) can be expressed as Y (t) = {a0X (t) + a1X (t-1). + A2X (t-2) + a3X (t-3) + a4X (t-4)} / Km. a0 and a1 to an represent amplitude correction coefficients. In (2), the value of these amplitude correction coefficients is 1, but in the filter unit 4 shown in FIG. .9) is used.

  Here, as an example, it is assumed that “a3X (t−3)” in Expression (7) includes a phase error. The vector “a3X (t−3)” corresponds to the sampling data Xt0-3 shown in FIG. 11, and the sampling data Xt0-3 is close to the sampling data Xt0-4 side due to the phase error. At this time, the filter unit 4 multiplies the data farthest in time series by an amplitude correction coefficient a0 other than 1. FIG. 11 shows a state where “X (t)” (sampling data Xt0) in equation (7) is multiplied by an amplitude correction coefficient a0 other than 1, and the vector of the sampling data Xt0 is the sampling data Xt0-4. It can be seen that it is longer than the vector.

  After multiplying the amplitude correction coefficient a0, the filter unit 4 adds the sampling data Xt0 and the four sampling data Xt0-1 to Xt0-4, and corrects the added data with the amplitude correction coefficient Km and relays it. Calculation data Xt2 is obtained. The vector indicated by the alternate long and short dash line is a vector of the relay calculation data Xt2 before (before correction) multiplication by the amplitude correction coefficient a0, and the vector indicated by the dotted line after being multiplied by the amplitude correction coefficient a0 (correction) This is a vector of the previous relay calculation data Xt2. The relay calculation data Xt2 before correction is close to the sampling data Xt0-4 side due to the influence of the phase error of the sampling data Xt0-3, but the relay calculation data Xt2 after correction is corrected to the sampling data Xt0 side. Yes. As a result, the time data t2 of the relay calculation data Xt2 matches the time data t0-2 of the sampling data Xt-2.

As described above, in the protective relay device 10 according to the fifth embodiment, the filter unit 4, if the phase error in the sampling value has occurred, sampling the base before time or time after the base time than Since one of the two sampling values farthest in time series among the recorded sampling values is multiplied by a coefficient other than 1, a phase error occurs in the time data from one sampling unit 2 Even in such a case, the phase error is corrected and the accuracy of the relay calculation can be improved.

  As described above, the present invention can be applied to a protective relay device that protects a system, and is particularly useful as an invention that can ensure the same time property between sampling data and relay operation data.

DESCRIPTION OF SYMBOLS 1,41 System electric quantity 2,42 Sampling part 3,5,7,43,45 Delivery line 4,44 Filter part 6 Calculation frequency processing part 8 Calculation part 9 Relay calculation part 10 Protection relay device 11, 13, 15, 21, 23, 25, 31, 33, 35 Time data storage area 12, 22, 32 Sampling data storage area 14, 24, 34 Filter data storage area 16, 26, 36 Relay operation data storage area 100, 101 Sampling circuit 102 Data Processing circuit Xt0 to Xt0 ± n Sampling data Xt1 to Xt1 ± n Filter data Xt2 to Xt2 ± n Relay operation data t0 to t0 ± n, t1 to t1 ± n, t2 to t2 ± n Time data

Claims (5)

A protective relay device that protects the power system based on the amount of electricity detected in the power system,
Sampling the electrical quantity at a predetermined sampling period to generate a plurality of sampling values, and a sampling unit that stores a sampling time representing a timing at which the sampling value is generated in association with each sampling value;
With the latest time of an odd number of sampling times consecutive in time series as a base time, a sampling value sampled at the base time, and a sampling value before the base time that is consecutive from subtracting 1 from the odd number, A filter data is obtained by adding , and a value obtained by multiplying the sampling period by a value obtained by subtracting 1 from the odd number and dividing by 2 is used as a delay time. A filter unit to be added to the filter data;
A relay operation unit that performs a relay operation using the sampling time and the filter data from the filter unit;
A protective relay device comprising: A protective relay device that protects the power system based on the amount of electricity detected in the power system,
Sampling the electrical quantity at a predetermined sampling period to generate a plurality of sampling values, and a sampling unit that stores a sampling time representing a timing at which the sampling value is generated in association with each sampling value;
At least a predetermined time before the base time is defined as a base time that is a time that is backed by a time that satisfies a value obtained by dividing a value obtained by subtracting 1 from the odd number by 2 from the latest time of an odd number of consecutive sampling times. A filter for obtaining filter data by adding a sampling value sampled at a time and a sampling value sampled at a time paired with the predetermined time after the base time, and adding the base time to the filter data And
A relay calculation unit that performs a relay calculation using the base time and the filter data from the filter unit;
A protective relay device comprising:   The protection relay device according to claim 2, wherein the filter unit adds a sampling value sampled at the base time when the filter data is obtained. The filter unit, when any of the base before time or the base time time to the sampled sampled values after following are missing, excluding the sampled sampled value at the time when forming the sampling values and pairs The protective relay device according to claim 2, wherein the filter data is obtained. The filter unit, when the phase error in the sampling value has occurred, either of the base time before or chronologically farthest two sampling values among the base point time time to the sampled sampled values after the following crab, protective relay apparatus according to multiplying the coefficients other than 1 claim 2, wherein in any one of four.

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