JP2004274930A - Digital type protective relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To individually perform a correction process without need for combining an input conversion means with an analog/digital conversion means at the time of replacing parts. <P>SOLUTION: This digital type protective relay includes the input conversion means and the analog/digital conversion means. A quantity of electricity which is outputted from the analog/digital conversion means and a quantity of reference electricity in an identical phase and an identical amplitude with the quantity of digital electricity of that quantity of electricity is inputted. This relay also includes a first phase gap/amplitude value calculating means which calculates the phase gap and the drift of amplitude value between both the input electricity quantity, a first memory means which stores data which is obtained by measuring the phase gap/the drift of amplitude value with the reference electricity quantity generated only by the input conversion means, a second phase gap/amplitude value calculating means which calculates the phase gap/the drift of amplitude value with the reference electricity quantity generated only by the analog/digital conversion means by using data stored in the first memory means and the value calculated by the first phase gap/amplitude value calculating means, and a second memory means which stores the data calculated by the second phase gap/amplitude value calculating means. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a digital protection relay.
[0002]
[Prior art]
When the power system is protected by a digital protection relay, in order to convert the analog amount of system electricity obtained by the voltage transformer and current transformer of the power system into digital data necessary for relay operation in a digital processor, First, the data is converted to a size that can be easily processed by the input conversion means. Then, unnecessary harmonic components unnecessary for the calculation are removed by an analog filter, and then sampled at a predetermined interval. It is converted into digital data (for example, see Patent Document 1).
[0003]
Active elements such as resistors and capacitors and logic ICs have individual differences among the elements constituting each means from the input conversion means to the analog / digital conversion means. There is a difference between the data and the phase or amplitude value. Therefore, when the calculation is performed by the relay calculation unit, it is necessary to perform a process of correcting these differences.
[0004]
FIG. 5 is a diagram showing a general configuration example of a digital protection relay.
The input conversion means 1 converts an analog input electric quantity a1 obtained from the system into an analog electric quantity a2 of a size appropriate for an electronic circuit, and converts this electric quantity a2 into a harmonic by an analog / digital conversion means 2. After removal, sampling is performed, converted into digital electric quantity d1, and output.
[0005]
The digital electric quantity d1 is input to the phase difference / amplitude value calculating means 3 in the next stage, where the phase difference and the amplitude difference (input amplitude) generated between the digital reference electric quantity dr and the digital output electric quantity d1 are generated. (Value / output amplitude value) is calculated.
[0006]
Then, the calculation result is stored in the storage unit 4. Based on the data stored in the storage means 4, a correction processing for normalizing the electric quantity of the system is performed by the electric quantity correction means 5, and a relay calculation is performed by the relay calculation means 7 using the data after the correction processing. Like that.
[0007]
[Patent Document 1]
JP-A-4-54815 (page 1-2, FIG. 4-5)
[0008]
[Problems to be solved by the invention]
As described above, in order to calculate the phase difference and the deviation of the amplitude value generated in the input conversion means 1 and the analog / digital conversion means 2, the input conversion means 1 and the analog / digital conversion means 2 must be combined. Therefore, when the input conversion means 1 and the analog / digital conversion means 2 are exchanged, the input conversion means 1 and the analog / digital conversion means 2 are recombined and the amplitude value and the phase shift are calculated again. There is a need.
[0009]
However, in this case, it takes a lot of time to reset the correction data when replacing parts, and it is necessary to pay close attention to prevent erroneous operation of the correction data setting work. Had become.
[0010]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has been made in consideration of a digital form in which correction processing can be performed individually without combining input conversion means and analog / digital conversion means when replacing parts. It is intended to provide a protective relay.
[0011]
[Means to solve the problem]
To achieve the above object, the invention of a digital protection relay according to claim 1 comprises an input conversion means for converting an electric quantity taken from a system into a value of an electric quantity necessary for performing an operation of the relay, Analog / digital conversion means for removing harmonic components from the electric quantity output from the input conversion means and converting the same into digital data; digital data output from the analog / digital conversion means and the same phase as the electric quantity of the system; A first phase difference / amplitude value calculating means for inputting both reference electric quantities having the same amplitude and calculating a phase difference and an amplitude value deviation between these two input electric quantities, and the input converting means. First storage means for storing data obtained by measuring a difference between a phase difference and an amplitude value from a reference electric quantity; and data stored in the first storage means and the first position. A second phase difference / amplitude value calculating means for calculating a phase difference and a deviation of an amplitude value from a reference electric quantity generated by the analog / digital conversion means using the value calculated by the difference / amplitude value calculating means; A second storage means for storing data calculated by the second phase difference / amplitude value calculation means, and correction using the data stored in the first storage means and the data stored in the second storage means, respectively. And electric quantity correction means.
[0012]
Further, the invention of a digital protection relay according to claim 3 is an input conversion means for converting an electric quantity taken from a system into a value of an electric quantity necessary for performing an operation of the relay, and an output from the input conversion means. Analog-to-digital conversion means for removing harmonic components from the electric quantity and converting the data to digital data, and a reference electric quantity having the same phase and the same amplitude as the digital data output from the analog / digital conversion means and the electric quantity of the system. A first phase difference / amplitude value calculating means for calculating a phase difference and a difference between amplitude values between these two input electric quantities, and an arbitrary electric quantity having a known phase and amplitude value as the analog signal. Calculates a phase difference and a difference between an amplitude value and a value output from the analog / digital conversion means when input to the digital / digital conversion means. Fourth phase difference / amplitude value calculation means, fourth storage means for storing the value calculated by the fourth phase difference / amplitude value calculation means, and data stored in the fourth storage means. And a third phase difference / amplitude value calculation for calculating a phase difference and an amplitude value deviation from a reference electric quantity generated by the input conversion means from a value calculated by the first phase difference / amplitude value calculation means. Means, a third storage means for storing the value calculated by the third phase difference / amplitude value calculation means, and correction by data stored in the third storage means and the fourth storage means. And electric quantity correction means.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the same parts throughout the drawings and described.
[0014]
(First Embodiment)
FIG. 1 is a block diagram of a digital protection relay according to a first embodiment of the present invention.
In FIG. 1, an analog input electric quantity a1 fetched from a transformer (not shown) is input to an input conversion means 1, converted into an analog electric quantity a2 having an appropriate size which is easy to process, and output. Further, the analog output electric quantity a2 is input to the analog / digital conversion means 2 and filtered to remove a higher harmonic component, sampled, and converted into a digital output electric quantity d1.
[0015]
In this embodiment, the phase difference between input and output electric quantities generated from the input conversion means 1 and the analog / digital conversion means 2 and the deviation of the amplitude value (input electric quantity amplitude value / output electric quantity amplitude value) are calculated. To do this, the digital output electric quantity d1 is input to the first phase difference / amplitude calculation means 3-1. On the other hand, the digital reference electric quantity dr set to the same phase and the same amplitude value as the analog input electric quantity a1 is input to the first phase difference / amplitude value calculating means 3-1.
[0016]
The first phase difference / amplitude calculating means 3-1 compares the input digital output electric quantity d1 with the digital reference electric quantity dr, and generates it through the input converting means 1 and the analog / digital converting means 2. The phase difference and the deviation of the amplitude value from the input electric quantity a1 are calculated.
[0017]
The analog input electric quantity a1 from the system and the digital output electric quantity d1 output via the input conversion means 1 and the analog / digital conversion means 2 have, for example, a phase difference of 30 ° and an amplitude value of six times. It is assumed that displacement has occurred.
[0018]
On the other hand, the input electric quantity a1 and the output electric quantity a2 of the input conversion means 1 are both analog quantities, and are not combined with other means. The phase difference and the deviation of the amplitude value can be measured independently. In the case of this embodiment, the phase difference generated by the input conversion unit 1 alone is, for example, 10 °, and the deviation of the amplitude value is, for example, twice. Then, the data of these phase difference; 10 ° and deviation of the amplitude value; twice is stored in the first storage means 4-1 detachably provided on the printed circuit board constituting the digital protection relay, and the digital protection relay is stored. To be implemented.
[0019]
Next, in the second phase difference / amplitude value calculation means 3-2, the data stored in the first storage means 4-1 (phase difference; 10 ° and amplitude value shift; twice) is compared with the data stored in the first storage means 4-1. A comparison operation for obtaining a difference from the data (the phase difference of 30 ° and the amplitude value of 6) calculated by the phase difference / amplitude value calculation means 3-1 of FIG.
[0020]
As a result of this comparison operation, a phase difference (30 ° −10 ° = 20 °) of the reference electric quantity and a deviation (6/2 = 3 times) of the amplitude value generated only by the analog / digital conversion means 2 are calculated. . This calculation data (phase difference; 20 ° and amplitude value deviation; triple) is stored in the second storage means 4-2.
[0021]
Then, the electric quantity correction means 5 stores the phase difference (30 °) and the deviation of the amplitude value (six times) generated through both the input conversion means 1 and the analog / digital conversion means 2 in the first storage means 4-1. Analog input electric quantity based on the phase difference of 10 ° and the data of twice the amplitude value shift inputted from the second storage means 4-2, The phase difference between a1 and the analog output electric quantity a2 is corrected (the phase is corrected to −30 °), and the deviation of the amplitude value is corrected (the amplitude value is reduced to １ ／). Using the corrected data, the relay calculation unit 7 performs a relay calculation.
[0022]
As described above, the phase difference and the deviation of the amplitude value in the input conversion unit 1 are individually calculated, and the calculated values are compared with the phase difference and the deviation of the amplitude value generated in the entirety of the input conversion unit 1 and the analog / digital conversion unit 2. , The difference between the phase difference and the amplitude value in the analog / digital conversion means 2 can be calculated.
[0023]
When the input conversion means 1 is replaced, the first storage means 4-1 storing the corresponding data (a phase difference of 10 ° and a displacement of twice the amplitude value) is also replaced together. When the conversion means 2 is replaced, the second storage means 4-2 storing the corresponding data (phase difference 20 °, amplitude value shift three times) is also replaced, so that the correction value calculation work can be performed. This can be omitted, and the time at the time of component replacement can be reduced, and erroneous setting of the correction value due to erroneous operation can be prevented.
[0024]
(Second embodiment)
FIG. 2 is a block diagram of a digital protection relay according to a second embodiment of the present invention.
In the second embodiment, the data stored in the first storage unit 4-1 and the second storage unit 4-2 described in the first embodiment is written by the newly provided writing unit 6. It is characterized by being arbitrarily rewritable. The other points are the same as in the first embodiment, and the description is omitted.
[0025]
By adopting such a configuration for the digital protection relay, if the input conversion means 1 is replaced, the corresponding data is reset in the first storage means 4-1 and the analog / digital conversion means 2 is replaced. At the time of exchange, it is only necessary to reset the corresponding data in the second storage means 4-2, and the first storage means 4-1 and the second storage means 4 as in the first embodiment described above. -2 does not need to be replaced.
[0026]
As a result, the operation time for calculating the correction data can be further reduced, and the time for replacing the component can be shortened, and erroneous setting of the correction data due to an erroneous operation can be prevented.
[0027]
(Third embodiment)
FIG. 3 is a block diagram of a digital protection relay according to a third embodiment of the present invention.
In FIG. 3, the first phase difference / amplitude value calculating means 3-1 includes an input converting means 1 and an analog / digital converting means 2 calculated from the digital output electric quantity d1 and the digital reference electric quantity dr in the same manner as described above. The data of the phase difference and the deviation of the amplitude value obtained through the above are once inputted to the third phase difference / amplitude value calculating means 3-3.
[0028]
On the other hand, in addition to the input / output of the analog electric quantity a2 and the digital electric quantity d1, a second analog input electric quantity a3 having a known phase and amplitude value is input to the analog / digital conversion means 2, A second digital electric quantity d2 corresponding to the two analog electric quantities a3 is output.
[0029]
The fourth phase difference / amplitude value calculation means 3-4 calculates the phase difference and amplitude value deviation generated only by the analog / digital conversion means 2 from the digital reference electric quantity dr and the second digital electric quantity d2. Data is calculated, and the data is stored in the fourth storage unit 4-4.
[0030]
The third phase difference / amplitude value calculation means 3-3 stores the data calculated by the first phase difference / amplitude value calculation means 3-1 and the data stored in the fourth storage means 4-4. By calculating the difference from the above, the data of the phase difference and the deviation of the amplitude value generated only in the input conversion means 1 is calculated, and the result is stored in the third storage means 4-3.
[0031]
The electric quantity correction means 5 corrects the phase difference and the deviation of the amplitude value between the input conversion means 1 and the analog / digital conversion means 2 stored in the third storage means 4-3 and the fourth storage means 4-4, respectively. Data is input to correct the difference between the analog input electric quantity a1 and the digital output electric quantity d1.
[0032]
As a result of this configuration, if the input conversion means 1 is replaced, the third storage means 4-3 storing the corresponding data is stored, and if the analog / digital conversion means 2 is replaced, the corresponding data is stored. By exchanging the fourth storage means 4-4, the operation of calculating the correction data can be omitted, and the time for replacing the parts can be shortened, and erroneous setting of the correction data due to an erroneous operation can be prevented.
[0033]
(Fourth embodiment)
FIG. 4 is a block diagram of a digital protection relay according to a fourth embodiment of the present invention.
In the fourth embodiment, the data stored in the third storage unit 4-3 and the data stored in the fourth storage unit 4-4 are arbitrarily written by the writing unit 6 as in the second embodiment. Can be rewritten. The other points are the same as in the third embodiment, and the description is omitted.
[0034]
According to the fourth embodiment, when the input conversion means 1 is replaced, the corresponding data is stored in the third storage means 4-3, and when the analog / digital conversion means 2 is replaced, the corresponding data is stored in the third storage means 4-3. By resetting the data in the storage means 4-4, the work time for calculating the correction data can be omitted, and the time at the time of component replacement can be reduced, and erroneous setting of the correction data due to erroneous operation can be prevented.
[0035]
【The invention's effect】
As described above, according to the present invention, when replacing the input conversion means or the analog / digital conversion means, it is possible to set the correction data for the phase difference and the deviation of the amplitude value prepared in advance. The time for resetting the correction data can be greatly reduced, and erroneous operation of the correction data setting operation can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram of a digital protection relay according to a first embodiment of the present invention.
FIG. 2 is a block diagram of a digital protection relay according to a second embodiment of the present invention.
FIG. 3 is a block diagram of a digital protection relay according to a third embodiment of the present invention.
FIG. 4 is a block diagram of a digital protection relay according to a fourth embodiment of the present invention.
FIG. 5 is a block diagram of a conventional digital protection relay.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Input conversion means, 2 ... Analog / digital conversion means, 3-1, 3-2, 3-3 ... Phase difference / amplitude value calculation means, 4-1, 4-2, 4-3 ... Storage means, 5 ... Electric amount correction means, 6 ... Write means, 7 ... Relay operation means, a1, a2, a3 ... Analog electric quantities, d1, d2 ... Digital output electric quantities, dr ... Digital reference electric quantities.

Claims (4)

Input conversion means for converting the amount of electricity taken from the grid into a value of the amount of electricity required to perform the operation of the relay;
Analog / digital conversion means for removing harmonic components from the electric quantity output from the input conversion means and converting the same into digital data;
Both the digital data output from the analog / digital conversion means and the reference electric quantity having the same phase and the same amplitude as the electric quantity of the system are inputted, and the phase difference and the deviation of the amplitude value between these input electric quantities are detected. First phase difference / amplitude value calculating means for calculating;
First storage means for storing data obtained by measuring a difference between a phase difference and an amplitude value from a reference electric quantity generated by the input conversion means,
Using the data stored in the first storage means and the value calculated by the first phase difference / amplitude value calculation means, the phase difference between the reference electric quantity generated by the analog / digital conversion means and Second phase difference / amplitude value calculating means for calculating a deviation of the amplitude value;
A second storage unit for storing the data calculated by the second phase difference / amplitude value calculation unit; and an electric quantity to be corrected using the data stored in the first storage unit and the data stored in the second storage unit, respectively. Correction means;
A digital protection relay comprising: 2. The digital protection relay according to claim 1, further comprising a writing unit capable of arbitrarily rewriting stored data in the first storage unit and the second storage unit. Input conversion means for converting the amount of electricity taken from the grid into a value of the amount of electricity required to perform the operation of the relay;
Analog / digital conversion means for removing harmonic components from the electric quantity output from the input conversion means and converting the same into digital data;
Both the digital data output from the analog / digital conversion means and the reference electric quantity having the same phase and the same amplitude as the electric quantity of the system are inputted, and the phase difference and the deviation of the amplitude value between these input electric quantities are detected. First phase difference / amplitude value calculating means for calculating;
When an arbitrary electric quantity having a known phase and amplitude value is input to the analog / digital conversion means, the phase difference and the deviation of the amplitude value between the value output from the analog / digital conversion means and the reference electric quantity are calculated. Fourth phase difference / amplitude value calculation means;
Fourth storage means for storing the value calculated by the fourth phase difference / amplitude value calculation means;
From the data stored in the fourth storage means and the value calculated by the first phase difference / amplitude value calculation means, the difference between the phase difference and the amplitude value between the reference electric quantity generated by the input conversion means is calculated. A third phase difference / amplitude value calculating means for calculating, a third storage means for storing a value calculated by the third phase difference / amplitude value calculating means,
An electric quantity correction means for correcting the data stored in the third storage means and the fourth storage means,
A digital protection relay comprising: 4. The digital protection relay according to claim 3, further comprising a writing unit capable of arbitrarily rewriting stored data in the third storage unit and the fourth storage unit.

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