JPH11308756A - System protection relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select and break the fault bus of a plurality of protection regions, without using relays for split protection. SOLUTION: Current data from all the current transformers that are connected to a bus with a plurality of protection regions of a power system are sampled at a specific time interval, digital data are obtained through a data acquisition means 11, the digital data are used for determining the internal/ external fault of a region including a plurality of protective regions according to a ratio differential operation by an operation means 12 for collective protection, at the same time the amount of operation being calculated individually for a plurality of protection regions by a fault bus judgment means 13 and the amount of operation which is calculated by an operation means 12 for collective protection are used for discriminating a protection region where an fault is, occuring, and a broken bus is determined from the determining result of the operation means for batch protection and that of the fault bus determining means at a breaking bus determining means 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system protection relay for a power system.

[0002]

2. Description of the Related Art Conventionally, when protecting a plurality of protection areas of a bus of an electric power system, a collective protection relay for judging internal / external accidents in an area including the plurality of protection areas, and each protection area In each case, a plurality of divided protection relays for judging internal / external accidents are individually provided, and the combination of these outputs is used to select and shut off an accident generating bus in a plurality of protection areas.

[0003]

In the above configuration,
Two or more protective relays were required to protect a bus having a plurality of protected areas. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a simple configuration without using a split protection relay, and a system protection relay capable of selecting and shutting down an accident-occurring bus in a plurality of protection areas with a simple configuration. It is intended to provide an electric device.

[0004]

According to a first aspect of the present invention, a system protection relay device according to a first aspect of the present invention samples a quantity of electricity of a power system at predetermined time intervals, and then uses the sampled data to generate a plurality of data. In a system protection relay that identifies and determines the occurrence of an accident in a protection area (section),
First operation means for calculating an operation amount and a suppression amount using the sampling data, and performing a predetermined ratio differential operation to discriminate between inside and outside accidents of the protection area including the plurality of protection areas (sections); Calculating an operation amount for each of the plurality of protected areas, and multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient. If greater than the value,
A second calculating means for satisfying the condition and detecting that an accident has occurred in each of the protected areas.

A system protection relay according to claim 1 of the present invention samples current data from a current transformer connected to a bus having a plurality of protection areas of a power system at predetermined time intervals. The digital data is obtained, and the digital data is used to obtain a judgment result of a collective protection operation means for judging internal / external accidents in an area including a plurality of protection areas by ratio differential operation. On the other hand, the amount of operation is calculated for each protection area individually, and the amount of operation (represented by IdA) and the amount of operation (Id) used for determining the arithmetic means for collective protection are calculated.
, For example, | IdA | ≧ K1 · | Id
When | (K1 is a predetermined coefficient) is satisfied, the judgment result of the accident bus judging means for judging that an accident has occurred in the protection area having obtained the operation amount of IdA is obtained. A system protection relay device that protects a system having a plurality of protection areas with a simple configuration by performing a determination of an interrupting bus in consideration of the determination result of the accident bus determination unit in addition to the determination result of the arithmetic unit for collective protection. Can be provided.

According to a second aspect of the present invention, there is provided a system protection relay device according to the first aspect, wherein a difference between the operation amount calculated by the first calculating means and the operation amount calculated individually for each protection area is provided. Is smaller than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient, an accident occurs in the protected area where the absolute value of the difference is obtained. Second calculating means for detecting the presence.

According to a third aspect of the present invention, there is provided a system protection relay device according to the first aspect, wherein the operation amount calculated for each of the plurality of protection areas and the operation amount calculated by the first calculating means are different from each other. In the meantime, there is provided a second calculating means for detecting that an accident has occurred inside the protection area when both of the following conditions a and b are satisfied. a. One of the absolute values of the operation amounts calculated individually for the protection areas is larger than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient. b. The phase difference between the operation amount of the protection region where the condition a is satisfied and the operation amount calculated by the first calculation means is smaller than a predetermined angle among the operation amounts calculated individually for the protection regions.

[0008] In the system protection relay device according to claim 4 of the present invention, in claim 3, the condition c described below is used instead of the condition a. c. Any one of the absolute values of the operation amounts calculated individually for the protection areas is larger than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient (a coefficient less than 1),
In addition, the value is smaller than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient (one or more coefficients).

The system protection relay according to claim 5 of the present invention provides the system protection relay according to claim 1, claim 3, or claim 4, wherein the amount of operation calculated by the first arithmetic means is defined as: The absolute value was set to the value shown in d below. d. Either the absolute value of the motion amount calculated by the first calculating means or a predetermined motion sensitivity value set in advance for determination by the first calculating means, whichever is larger.

The system protection relay according to claim 6 of the present invention is the system protection relay according to claim 1, claim 3 or claim 4, wherein the operation amount calculated by the first arithmetic means is calculated by the first arithmetic means. The absolute value was set to the value shown in e below. e. A value obtained by adding a predetermined operation sensitivity value set in advance for determination by the first arithmetic unit to the absolute value of the operation amount calculated by the first arithmetic unit.

According to a seventh aspect of the present invention, there is provided a system protection relay device according to the second aspect, wherein the operation amount calculated by the first calculating means and any one of the operation amounts calculated individually for the protection area. Is smaller than a value obtained by multiplying the absolute value of the amount of operation calculated by the first calculating means by a predetermined coefficient, and the amount of operation calculated individually for each protection area where this condition is satisfied. Is larger than a value obtained by multiplying a predetermined value (a value equal to or less than 1) by an operation sensitivity value set in advance for the determination by the first arithmetic means, and an accident has occurred in the area. Is provided.

[0012] In the system protection relay device according to claim 8 of the present invention, in claim 1, the operation amount calculated for each of the plurality of protection areas and the operation amount calculated by the first calculating means are different. In the meantime, there is provided a second calculating means for detecting that an accident has occurred inside the protection area when both of the following conditions f and g are satisfied. f. Any one of the absolute values of the operation amounts calculated individually for the protection areas is the difference between the absolute value of the operation amount calculated by the first operation unit and the operation sensitivity value set in advance for the determination of the operation result of the first operation unit. It is larger than a value obtained by multiplying a larger value by a predetermined coefficient. g. The absolute value of the difference between the movement amount calculated by the first calculation means and any movement amount calculated individually for the protection area is obtained by multiplying the absolute value of the movement amount calculated by the first calculation means by a predetermined coefficient. Less than

[0013] The system protection relay device according to claim 9 of the present invention samples electric quantities of the electric power system at predetermined time intervals, and then uses these sampled data to form two protection areas (sections). On the other hand, in a system protection relay device for performing accident detection determination, an operation amount and a suppression amount are calculated using the sampling data, and a protection ratio of the protection region including the two protection regions (sections) is calculated by a predetermined ratio differential operation. First calculating means for distinguishing between internal and external accidents;
The operation amount is calculated for each of the two protection areas, and if one of the calculated absolute values of the operation amounts is smaller than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient, the other And a second calculating means for detecting that an accident has occurred inside the protection area.

According to a tenth aspect of the present invention, in the system protection relay device according to the ninth aspect, one of the absolute values of the operation amounts calculated separately for the two protection areas is determined by the first computing means. Is larger than a value obtained by multiplying the absolute value of the operation amount calculated in the above by a predetermined value, and the absolute value of the operation amount calculated in the other protection area is the absolute value of the operation amount calculated by the first calculating means. If the value is smaller than a value obtained by multiplying the value by a predetermined value, it is detected that an accident has occurred in the protection area in which the operation amount on the side larger than the operation amount calculated by the first calculation means is obtained. Calculation means.

[0015]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, a bus protection relay device 10 comprises a data acquisition means 11 for sampling current from a current transformer connected to a bus having a plurality of protection areas at predetermined time intervals to obtain digital data, Collective protection calculating means 12 for determining an inside / outside accident of an area including a plurality of protection areas by a predetermined ratio operation calculation using data, and calculating the operation amounts individually for the plurality of protection areas, and the calculated operation Using the amount and the operation amount calculated by the collective protection arithmetic means, an accident bus determination means 13 for performing an accident bus determination, and an internal / external accident determination output of the collective protection arithmetic means 12 and an accident bus determination means 13 And a cut-off bus determination means 14 for obtaining a cut-off bus determination output from the accident bus determination output.

The operation means 12 for collective protection uses the currents from the current transformers for n lines connected to the buses of the area including the plurality of protection areas, and calculates the operation amount according to the equation (1) and ( 2) The suppression amount is calculated by the expression, and an operation signal is output when a predetermined relational expression of these calculated amounts is established.

[0017]

(1) Id (= i1 + i2 +... + In) (1) Ir (= | i1 | + | i2 | +... + | In |) (2)

Accident bus judging means 13 for judging an accident bus
In order to identify individual areas for the plurality of protection areas, for example, a disconnector condition of each line is fetched.
The identification of the protection area based on the disconnector condition is performed by a known means, and thus the description is omitted. FIG. 2 shows an example of a configuration of a bus having a plurality of protection areas.

The bus is divided into a bus BA and a bus BB with the circuit breaker CB0 interposed therebetween. The protection area is A on the bus BA side.
The area is divided into two protection areas: an area and a B area on the side of the bus BB. At this time, the accident bus judging means 13 calculates the operation amounts IdA and IdB for each of the protection areas, and judges the accident bus according to a predetermined calculation.

Here, the feature of the operation amount (differential current) generated at the time of an accident will be described with reference to FIG. 3 showing an example of an accident current flowing through a bus having two protection regions. In FIG. 3, the bus is a bus BA and a bus BB with the circuit breaker CB0 interposed therebetween.
The transmission lines L1 and L3 are connected to the bus BA, and the transmission lines L2 and L4 are connected to the bus BB.

Circuit breakers CB1, CB2, CB3, CB4 and current transformers CT1, C2 are connected to the transmission lines L1, L2, L3, L4.
T2, CT3, and CT4 are provided, and current transformers CTA and CTB are provided at both ends of the circuit breaker CB0. Assuming that the current flowing through each CT is i1, i2, i3, i4, iTA, iTB, the differential current I
d and differential currents IdA and Id calculated individually for the protection area
B is given by equations (3), (4) and (5).

[0022]

Id = i1 + i2 + i3 + i4 (3) IdA = i1 + i3 + iTA (4) IdB = i2 + i4 + iTB (5)

If an accident occurs inside the bus BA, the current from the transmission lines L2 and L4 flows into the bus BA via the circuit breaker CB0. Assuming that the fault current at this time is IF and the current passing through the circuit breaker CB0 is IT, the relationships of equations (6) and (7) are established between the currents according to Kirchhoff's law. When rearranging equations 4) and (5),
Equations (8), (9) and (10) are obtained.

[0024]

## EQU00003 ## IT = iTA = -iTB = i2 + i4 (6) IF = i1 + i3 + iTA (7) Id = IF... (8) IdA = IF .................. (9) IdB = 0 ........................ (10)

As described above, when an accident occurs inside the bus, the differential current generated in the region including the two regions is reduced by the protection current in the two protection regions inside the bus. The amount is the same as the differential current generated in the region.

Therefore, the operation amount Id calculated by the collective protection operation means 12 is compared with the two operation amounts (IdA or Id
By comparing B) and confirming that a predetermined relationship is established between the two, it is possible to determine the accident bus (any one of the two areas).

Next, an accident bus determination means using the characteristic principle diagram
The thirteen operation principles will be described. 4 to 7 show the relationship between the operation amount (Id) calculated by the collective protection operation unit 12 and the operation amount (operation amount on the accident bus side: IdA) individually calculated for a plurality of protection areas by the accident bus determination unit 13. FIG. 4 is a characteristic principle vector diagram showing a relationship.

FIG. 4 shows the first embodiment, in which the absolute value of Id and the absolute value of IdA are compared to determine the accident occurrence area. If an accident occurs in the area A, IdA and Id are in principle the same amount. On the other hand, even if the error is taken into consideration, IdA takes a value close to Id, so that the absolute value of Id and the absolute value of IdA may be considered to be substantially the same value. In the description in FIGS. 4 to 7, the area A means “area A in the bus shown in FIG. 2” or “protected area for obtaining the operation amount IdA”.

Using this, if the relationship represented by the equation (11) is established between the absolute value of IdA and the absolute value of Id, the operation amount I
It is determined that an accident has occurred in the area A for which dA has been calculated. Similarly, when the relationship expressed by the equation (12) is established when an accident occurs in the B region, it is determined that the accident has occurred in the B region for which the operation amount IdB has been calculated.

[0030]

| IdA | ≧ K1 · | Id | (11) (K1 is a coefficient of 1 or less) | IdB | ≧ K1 · | Id | (12) (K1 Is a predetermined coefficient)

FIG. 5 shows the second embodiment, in which after calculating the absolute value | IdA-Id | of the difference between IdA and Id, I
This shows a method of comparing the absolute value of d with the absolute value of d to determine an accident occurrence area. When an accident occurs in the area A, IdA and Id have the same vector value.

Therefore, the difference between IdA and Id corresponds to an error vector, and cannot be a large value in the event of an accident in the region A. From this, the absolute value of the difference between IdA and Id and I
When the relationship between the absolute value of d and the value of Expression (13) is established, it is determined that an accident has occurred in the region A where the operation amount IdA has been calculated.

[0033]

| IdA−Id | ≦ K2 · | Id | (13) (K2 is a coefficient of 1 or less)

FIG. 6 shows the third embodiment, which is a system in which the phase comparison of Id and IdA is added to the characteristic principle vector diagram of FIG. As described above, when an accident occurs in the region A, since IdA and Id have the same amount in vector, it can be said that the phase is substantially the same as the scalar amount.
From this, when the relationship of the expression (14) is established in addition to the establishment of the expression (11), it is determined that an accident has occurred in the region A where the operation amount IdA has been calculated.

[0035]

[6] ^{| Id ∧ IdA | ≦ α ...........................} (14) (α is a predetermined phase angle)

FIG. 7 shows a fourth embodiment in which the condition for giving an upper limit to the absolute value of IdA is added to the equation (11) showing the relationship between the absolute value of Id and the absolute value of IdA. It is. When an accident occurs in the region A, since IdA and Id have substantially the same value, the absolute value of IdA does not greatly exceed the absolute value of Id. From this, the relationship of the formula (15) is established between the absolute value of IdA and the absolute value of Id, and when the formula (14) is satisfied, an accident occurs in the region A where the operation amount IdA is calculated. Is determined.

[0037]

K1 · | Id | ≦ | IdA | ≦ K3 · | Id | (15) (K1 is a coefficient of 1 or less, K3 is a coefficient of 1 or more)

Here, the absolute value of the operation amount at the time of occurrence of an accident is
Sensitivity value (KTAP) set in advance for performing internal / external accident determination in at least the protection means
Should be larger than Therefore, it can be said that the absolute value of IdA when an accident occurs in the region A is larger than this sensitivity value.

From this, in the relational expression (11) between the absolute values of IdA and Id, the sensitivity value (K
TAP) is considered and the formula (16) is used, so that it is possible to prevent a transient erroneous operation at the initial stage of an accident with a small operation amount in normal times. Further, the condition of the expression (16) is set as an AND condition with the expression (14), so that the accident bus determination can be performed.In addition, the accident bus determination can be performed as the expression (17) in combination with the expression (15). .

[0040]

| IdA | ≧ K1 · max {| Id |, KTAP} (16) Note that max {A, B} indicates a larger value among A and B. K1 · (max {| Id |, KTAP} ≦ | IdA | ≦ K3 · | Id | (17) (K1 is a coefficient of 1 or less, and K3 is a coefficient of 1 or more. )

Similarly, it is also effective to use the sensitivity value to set the lower limit value of the operation amount and to use the sensitivity value as equation (18). In order to prevent erroneous detection in a small current region, there is a method of setting a value obtained by multiplying a sensitivity value (KTAP) by a predetermined coefficient as a lower limit value of the operation amount IdA, and using the expression (19). This equation (19) becomes (1
By setting an AND with the expression 3), it is possible to determine the accident bus. Further, in the above determination formula, the formula (13) and (1
By setting the expression 6) as an AND condition, a more reliable accident bus determination can be performed.

[0042]

| IdA | ≧ K1 · (| Id | + KTAP) (18) | IdA | ≧ K4 · KTAP (19) (K4 is a coefficient of 1 or less)

Next, consider the case where the number of protected areas is limited to two. When an accident occurs in the area A of the two protection areas A and B, the operation amount of the area A is the same as the operation amount Id of the operation means for collective protection as described above.
At this time, the operation amount IdB in the B region does not occur (only the error amount).

Accordingly, as a condition for detecting the occurrence of an accident in the region A, it is considered that the expression (20) is established between the absolute value of IdB and the absolute value of Id. However, the region A is obtained only by the judgment of the expression (20).
When no accident has occurred in both areas B, it is necessary to add a condition that an accident has occurred in any one of the areas in order to determine that an accident has occurred in the other area.

As this condition, the condition of the equation (11) using the absolute value of the operation amount IdA and the absolute value of Id in the region A is added, and (2)
When the condition is satisfied at the same time as equation (0), it is determined that an accident has occurred in the area A. Similarly, the condition in which an accident has occurred in the area B is determined based on the satisfaction of both conditions of the equations (21) and (22).

[0046]

| IdB | ≦ K5 · | Id | (20) (K5 is a coefficient of 1 or less) | IdA | ≦ K5 · | Id | (21) | IdB | ≦ K1 · | Id | ............ (22)

The shutoff bus judging means 14 judges the shutoff bus by combining the internal / external accident judgment output from the collective protection calculating means 12 with the judgment result of the accident bus judging means 13. For example, when the operation means for collective protection makes an internal accident judgment and the accident bus judging means outputs an accident judgment in the area A, a cut-off output for the line connected to the bus in the area A is activated. The determination by the shutoff bus determining means is performed according to the collective Table 1, whereby the start of shutoff of the accident occurrence area (the accident bus connection line) is performed.

In the above description of the embodiment, the bus system is taken as an example, but the present invention is not limited to this. In short, the same effect can be obtained if the system has a configuration including a plurality of protection areas to which protection based on the differential operation principle is applied.

[0049]

[Table 1]

[0050]

As described above, according to the present invention, in a collective protection relay for performing an internal / external accident judgment for an area including a plurality of protection areas, the operation amount calculated for the judgment and An accident system determination function has been added that can determine the protection area in which an accident has occurred using the operation amounts calculated separately for multiple protection areas. It is possible to provide a system protection relay device that can select and cut off an accident-occurring bus in an area.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of a system protection relay device according to the present invention.

FIG. 2 is a configuration example of a bus having a plurality of protection areas.

FIG. 3 is a protection system diagram for explaining the embodiment of the present invention.

FIG. 4 is a characteristic principle diagram showing the first embodiment.

FIG. 5 is a characteristic principle diagram showing a second embodiment.

FIG. 6 is a characteristic principle diagram showing a third embodiment.

FIG. 7 is a characteristic principle diagram showing a fourth embodiment.

[Explanation of symbols]

 10 Bus protection relay 11 Data acquisition means 12 Computing means for collective protection 13 Accident bus judgment means 14 Interruption bus judgment means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kuniyasu Inamura 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant (72) Inventor Hiroshi Nishida 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Corporation In the head office (72) Inventor Masato Okazaki 2-24-24 Harumicho, Fuchu-shi, Tokyo Toshiba System Technology Corporation

Claims (10)

[Claims] 1. A system protection relay device that samples an amount of electricity in a power system at predetermined time intervals, and identifies and determines the occurrence of an accident in a plurality of protection areas (sections) using the sampled data. A first operation for calculating an operation amount and a suppression amount using the sampling data, and performing a predetermined ratio differential operation to discriminate between inside and outside accidents of the protection area including the plurality of protection areas (sections). Means, while calculating the operation amount individually for the plurality of protection areas, any one of the absolute values of the operation amount calculated here,
If the absolute value of the amount of operation calculated by the first arithmetic means is larger than a value obtained by multiplying the absolute value by a predetermined coefficient, it is determined that an accident has occurred within the individual protection area satisfying the condition. A system protection relay device comprising: a second calculating means. 2. The system protection relay device according to claim 1, wherein an absolute value of a difference between the operation amount calculated by the first calculation means and the operation amount calculated for each protection area is equal to the first value.
If the absolute value of the operation amount calculated by the calculation means is smaller than a value obtained by multiplying the absolute value by a predetermined coefficient, a second detection is performed to detect that an accident has occurred inside the protection area from which the absolute value of the difference has been obtained. A system protection relay comprising a calculating means. 3. The system protection relay device according to claim 1, wherein a and b shown below are set between the operation amounts calculated individually for the plurality of protection areas and the operation amounts calculated by the first calculating means. The system protection relay device comprises a second calculating means for detecting that an accident has occurred inside the protection area when both of the conditions are satisfied. a. One of the absolute values of the operation amounts calculated individually for the protection areas is larger than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient. b. The phase difference between the operation amount of the protection region where the condition a is satisfied and the operation amount calculated by the first calculation means is smaller than a predetermined angle among the operation amounts calculated individually for the protection regions. 4. The system protection relay device according to claim 3, wherein the following condition c is used instead of condition a. c. Any one of the absolute values of the operation amounts calculated individually for the protection areas is larger than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient (a coefficient less than 1),
In addition, the value is smaller than a value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined coefficient (one or more coefficients). 5. The system protection relay according to claim 1, wherein the absolute value of the operation amount calculated by the first calculating means is a value represented by the following d. Characteristic system protection relay. d. Either the absolute value of the motion amount calculated by the first calculating means or a predetermined motion sensitivity value set in advance for determination by the first calculating means, whichever is larger. 6. The system protection relay according to claim 1, wherein the absolute value of the operation amount calculated by the first calculating means is a value represented by the following e. A system protection relay device characterized by the following. e. A value obtained by adding a predetermined operation sensitivity value set in advance for determination by the first arithmetic unit to the absolute value of the operation amount calculated by the first arithmetic unit. 7. The system protection relay device according to claim 2, wherein an absolute value of a difference between the operation amount calculated by the first calculation unit and any operation amount calculated individually for the protection area is equal to the first value. Is smaller than the value obtained by multiplying the absolute value of the amount of operation calculated by the calculating means by a predetermined coefficient, and the amount of operation calculated individually for each protection area satisfying this condition is determined by the first calculating means. For this reason, a second arithmetic means is provided for detecting that an accident has occurred inside the area by setting the value to be larger than a value obtained by multiplying a predetermined value (a value equal to or less than 1) by a preset operation sensitivity value. System protection relay device characterized by the following. 8. The system protection relay device according to claim 1, wherein f, f and f shown below are between an operation amount calculated for each of the plurality of protection areas and an operation amount calculated by the first calculation means.
A system protection relay device comprising: a second calculating means for detecting that an accident has occurred inside the protection area when both of the conditions of g are satisfied. f. Any one of the absolute values of the operation amounts calculated individually for the protection areas is the difference between the absolute value of the operation amount calculated by the first operation unit and the operation sensitivity value set in advance for the determination of the operation result of the first operation unit. It is larger than a value obtained by multiplying a larger value by a predetermined coefficient. g. The absolute value of the difference between the movement amount calculated by the first calculation means and any movement amount calculated individually for the protection area is obtained by multiplying the absolute value of the movement amount calculated by the first calculation means by a predetermined coefficient. Less than 9. A system protection relay device, which samples electric quantities of a power system at predetermined time intervals, and performs an accident detection determination on two protection areas (sections) using the sampled data. First calculating means for calculating an operation amount and a suppression amount using the sampling data, and performing a predetermined ratio differential operation to discriminate between inside and outside accidents of the protection area including the two protection areas (sections);
A case where one of the absolute values of the calculated amount of operation is calculated by multiplying the absolute value of the amount of operation calculated by the first calculating means by a predetermined coefficient, And a second calculating means for detecting that an accident has occurred inside the other protection area. 10. The system protection relay device according to claim 9, wherein one of the absolute values of the operation amounts calculated separately for the two protection areas is set to the absolute value of the operation amount calculated by the first calculating means. Greater than the product of
When the absolute value of the operation amount calculated in the other protection area is smaller than a value obtained by multiplying the absolute value of the operation amount calculated by the first arithmetic unit by a predetermined value, the calculation is performed by the first arithmetic unit. A second method for detecting that an accident has occurred inside the protection area that has obtained an operation amount larger than the operation amount
A system protection relay device comprising: