KR19990083313A - System protection relay equipment - Google Patents

Abstract

The present invention relates to a system protection relay device that selects and interrupts fault buses of a plurality of protection regions without using a split protection relay.

After sampling the current data from all the current transformers connected to the buses having a plurality of protection areas of the power system at predetermined time intervals, the digital data is obtained by the data acquiring means 11, and the calculation for collective protection using the digital data is performed. The means 12 perform internal and external accident determination of the area including the plurality of protection areas by ratio differential calculation, and at the same time, the amount of operation and collective protection calculated by the accident bus determination unit 13 individually for the plurality of protection areas. The operation area calculated by the calculation means 12 of the control unit determines the protection area in which the accident occurs, and the breaking bus determination unit 14 determines the determination result of the calculation means for the collective protection and the determination of the accident bus determination unit. From the result, the determination of the breaking bus is carried out.

Description

Grid protective relay {SYSTEM PROTECTION RELAY EQUIPMENT}

The present invention relates to a grid protection relay device of a power system.

Conventionally, in the case of protecting a plurality of protection areas of a bus system of a power system, a collective protection relay for performing internal and external accident determination for areas including the plurality of protection areas, and internal and external for each protection area. A plurality of divided protection relays for performing an accident determination were separately provided and these outputs were combined to select and interrupt an accident occurrence busbar in a plurality of protection areas.

In the above configuration, two or more protective relays were required to protect the bus bar having a plurality of protective regions. The present invention has been made to solve the above problems, and an object of the present invention is to provide a system protection relay device capable of selecting and interrupting an accident occurrence bus in a plurality of protection areas with a simple configuration without using a divided protection relay. have.

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

2 is a structural example of a bus bar having a plurality of protection regions.

Figure 3 is a protective schematic diagram for explaining an embodiment of the present invention.

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

Fig. 5 is a characteristic principle diagram showing the second embodiment.

Fig. 6 is a characteristic principle diagram showing the third embodiment.

Fig. 7 is a characteristic principle diagram showing the fourth embodiment.

[Description of the code]

10 busbar protection relay

11 data acquisition means

12 calculation means for collective protection

13 accident busbar judging means

14 bus bar determination means

The grid protective relay device according to claim 1 of the present invention samples the electricity amount of the power grid at predetermined time intervals, and then uses the sampling data to identify and determine the occurrence of an accident in a plurality of protected areas (sections). In the system protection relay which implements, the operation amount and the suppression amount are calculated using the sampling data, and internal / external accident of the protection area including the plurality of protection areas (sections) by a predetermined ratio differential calculation. The first calculation means for discriminating and the operation amount are calculated for each of the plurality of protection areas individually, and any one of the absolute values of the operation amount calculated here is applied to the absolute value of the operation amount calculated by the first calculation means. When larger than the value multiplied by a predetermined coefficient, the second calculation means for establishing the condition and detecting that an accident has occurred in the individual protection area is determined. Equipped.

The grid protective relay device according to "claim 1" of the present invention obtains digital data by sampling current data from a current transformer connected to a bus bar having a plurality of protection areas of a power system at predetermined time intervals, and uses the digital data. By the ratio differential calculation, the determination result of the calculation means for collective protection which performs the internal and external accident determination of the area including the plurality of protection areas is obtained. On the other hand, an operation amount is calculated for each protection area individually, and a predetermined relationship, for example, IdA≥k1 * Id between these operation amounts (represented by IDA) and the operation amount Id used for determination of the calculation means for collective protection. When (k is a predetermined coefficient), the determination result of the accident bus determination unit which determines that an accident has occurred in the protected area where the operation amount of IdA is obtained is obtained. The determination result of the accident bus determination means can be added to the determination result of the calculation means for collective protection, and the system protection relay apparatus which protects the system which has a some protection area by simple determination can be provided.

In the system protection relay apparatus according to "Claim 2" of the present invention, in "Claim 1", the absolute value of the difference value between the operation amount calculated by the first calculation means and the operation amount calculated for each protection area is calculated by the first operation. When the absolute value of the operation amount calculated by the means is smaller than the value multiplied by a predetermined coefficient, a second calculating means is provided for detecting that an accident has occurred inside the protection area obtained from the absolute value of the difference value.

In the system protection relay apparatus according to "Claim 3" of the present invention, in "Claim 1", a and b are shown below between an operation amount calculated for each of a plurality of protection regions individually and an operation amount calculated by said first calculation means. By simultaneously establishing the conditions, the second calculation means for detecting that an accident has occurred inside the protection area was provided.

a. Any one of the absolute values of the operation amount calculated for each protection area is larger than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient.

b. The phase difference between the operation amount of the protection area in which the condition a is satisfied and the operation amount calculated by the first calculation means is smaller than the predetermined angle among the operation amounts calculated for the protection areas individually.

In the "claim 3", the system protective relay device according to "claim 4" of the present invention was set to c condition shown below instead of a condition.

c. Any one of the absolute values of the operation amount calculated for each protection area is larger than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient (coefficient less than 1), and the operation calculated by the first calculation means. It is smaller than the value obtained by multiplying the absolute value of the quantity by a predetermined coefficient (coefficient of one or more).

In the system protection relay apparatus according to "Claim 5" of the present invention, in "Claim 1" or "Claim 3" or "Claim 4", the absolute value of the operation amount calculated by the first calculation means is represented by d below. It was made.

d. A large value of either the absolute value of the operation amount calculated by the first calculating means or the predetermined operation sensitivity value preset for the determination of the first calculating means.

In the system protection relay apparatus according to "Claim 6" of the present invention, in "Claim 1" or "Claim 3" or "Claim 4", the absolute value of the operation amount calculated by the first calculation means is represented by e. It was made.

e. A value obtained by adding a predetermined operation sensitivity value preset for the determination of the first calculation means to the absolute value of the operation amount calculated by the first calculation means.

In the system protection relay apparatus according to "Claim 7" of the present invention, in "Claim 2", the absolute value of the difference value between the operation amount calculated by the first calculation means and any one operation amount calculated by the protection area is calculated as described above. The operation sensitivity set in advance for the determination of the first calculating means by reducing the absolute value of the operating amount calculated by the first calculating means by a value obtained by multiplying the predetermined coefficient, and also by calculating the individual protection areas where this condition is satisfied. When the value is larger than the value multiplied by a predetermined value (value equal to or less than 1), a second calculating means for detecting that an accident has occurred inside the area is provided.

In the system protection relay device according to "Claim 8" of the present invention, in "Claim 1", f, g shown below between an operation amount calculated by a plurality of protection areas individually and an operation amount calculated by a first calculation means When all of the conditions are satisfied, the second calculation means for detecting that an accident has occurred inside the protection area is provided.

f. Either of the absolute values of the operation amounts calculated for each protection area individually is either the absolute value of the operation amount calculated by the first calculation means or the operation sensitivity value preset for the determination of the calculation result of the first calculation means. It is larger than the value multiplied by the predetermined coefficient.

g. The absolute value of the difference value between the operation amount calculated by the first calculation means and any one operation amount calculated individually for the protection area is smaller than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient.

The system protective relay device according to claim 9 of the present invention samples the electricity amount of the power system at predetermined time intervals, and then uses the sampling data to perform an accident detection determination on two protection areas (sections). In the protective relay device, the operation amount and the suppression amount are calculated using the sampling data, and the internal and external accidents of the protection area including the two protection areas (sections) are distinguished by a predetermined ratio differential calculation. The first calculation means and the operation amount are calculated for each of the two protection areas individually, and one of the absolute values of the calculated operation amounts is greater than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient. When small, the second calculation means for detecting that an accident has occurred inside the other protection area is provided.

In the system protection relay apparatus according to "claim 10" of the present invention, in "claim 9", one of the absolute values of the operation amounts calculated for each of the two protection areas is set to the absolute value of the operation amounts calculated by the first calculation means. When the absolute value of the operation amount calculated in the other protection area is smaller than the value multiplied by the predetermined value and the absolute value of the operation amount calculated by the first calculation means is smaller than the value multiplied by the predetermined value, the first value is obtained. The second calculation means for detecting that an accident has occurred in the protection area obtained with the operation amount larger than the operation amount calculated by the calculation means was provided.

EXAMPLE

1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the bus protection relay 10 includes data acquisition means 11 for sampling digital current from a current transformer connected to a bus having a plurality of protection areas at predetermined time intervals to obtain digital data, and the digital data. Operation for calculating collective operation means 12 for performing internal and external accident determination of an area including a plurality of protection areas by a predetermined ratio operation calculation, and an operation amount for each of the plurality of protection areas, and calculating The accident bus determination means 13 which performs the accident bus determination using the amount and the operation amount calculated by the calculation means for collective protection, the internal / external accident judgment output of the collective protection calculation means 12 and the accident bus determination means ( It becomes the interruption bus determination device 14 which obtains a interruption bus determination output from the accident bus determination decision output of 13).

In the collective protection calculation means 12, the amount of operation according to formula (1) and the amount of suppression according to formula (2) using current from an n-line current transformer connected to the bus bar of the region including the plurality of protection regions. Is calculated, and an operation signal is output when predetermined relational expressions of these calculation schemes are satisfied.

Id (= i1 + i2 + ... + in)... … (One)

Ir (= i1 + i2 + ... + in)... … (2)

In the accident busbar judging means 13 which performs the accident busbar judging, in order to identify individual areas with respect to the said plurality of protection areas, the disconnection condition of each line is introduced, for example. Since identification of the protection area by disconnection condition is by a well-known means, description is abbreviate | omitted. 2 is a configuration example of a bus bar having a plurality of protection regions.

The bus bar is divided into bus bar BA and bus bar BB with breaker CB0 interposed therebetween. The protection area is divided into two protection areas: A area on the bus bar side and B area on the bus line BB side. At this time, the accident busbar judging means 13 calculates the operation amounts IdA and IdB for the respective protection areas, and discriminates the accident busbars according to a predetermined calculation.

Here, FIG. 3 which shows the fault current which flows through the bus bar which has two protection areas about the characteristic of the operation | movement amount (differential current) which arises at the time of an accident is demonstrated as an example. In FIG. 3, the bus is divided into a bus BA and a bus BB with the breaker CB0 interposed therebetween, and the bus BA transmits power lines L1 and L3 and the bus BBB transmits power lines L2 and L4. Is connected.

Breakers CB1, CB2, CB3, and CB4 and current transformers CT1, CT2, CT3, and CT4 are installed at transmission lines L1, L2, L3, and L4, and current transformers CTA and CTB are provided at both ends of the breaker CB0. have. If the currents flowing through the CTs are i1, i2, i3, i4, iTA, and iTB, the differential current Id calculated by the collective protection calculating means 12 and the differential currents IdA and Id calculated separately from the protection area are (3), (4) and (5).

Id = i1 + i2 + i3 + i4... … (3)

IdA = i1 + i3 + iTA... … (4)

IdB = i2 + i4 + iTB... … (5)

Here, if an accident occurs inside the bus BA, current from the power transmission lines L2 and L4 flows into the bus BA through the breaker CB0. If the fault current at this time is IF and the current passing through the breaker CB0 is IT, Kirchhoff's law establishes the equations (6) and (7) between the currents. ) And (5), the equations (8), (9) and (10) are obtained.

IT = iTA = −iTB = i2 + i4... … (6)

IF = i1 + i3 + iTA... … (7)

Id = iF... … (8)

Id = IF… … (9)

IdB = 0... … 10

As described above, when an accident occurs inside the bus, the differential current generated in the area including the two areas is equal to the differential current generated in the protected area where the accident occurs among the two protection areas inside the bus.

Therefore, with respect to the operation amount Id calculated by the collective protection calculating means 12, the two operation amounts IdA or Id calculated by the accident bus determination unit 13 separately for the protection areas are compared, respectively, and a predetermined relationship therebetween. Is confirmed, the determination of the accident busbar (one of the two areas) becomes possible.

Next, the calculation principle of the accident busbar judging means 13 will be described using the characteristic principle diagram. 4 to 7 show the operation amount Id calculated by the collective protection calculation means 12 and the operation amount calculated by the accident bus determination unit 13 individually for a plurality of protection areas (operation amount on the accident bus side: IDA). The characteristic principle vector diagram which shows the relationship with).

4 shows a first embodiment, and shows a method of determining an accident occurrence area by comparing an absolute value of Id and an absolute value of IdA. In the event of an accident in the area A, IdA and Id are in principle equal amounts. On the other hand, even when the error value is considered, since IdA takes a value close to Id, the absolute value of Id and the absolute value of IdA may be regarded as almost the same value. In the description of FIGS. 4 to 7, the meaning of the area A is "area A in the bus bar shown in FIG. 2" or "protected area for obtaining the operating amount IdA".

Using this, if the relationship of the expression (11) is established between the absolute value of IdA and the absolute value of Id, it is determined that an accident has occurred in the area A where the operation amount IdA is calculated. Similarly, even when an accident occurs in the area B, if the relationship of the expression (12) is established, it is determined that the accident has occurred in the area B where the operation amount IdB is calculated.

IdA? … (11)

(K1 is the coefficient below 1)

IdB? K1? … (12)

(K1 is a predetermined coefficient)

Fig. 5 shows a second embodiment, and shows a method of determining an area where an accident occurs by calculating the absolute value IdA-Id of the difference value between IdA and Id and comparing it with the absolute value of Id. In the case of an accident in the area A, IdA and Id are the same in vector.

Therefore, the difference between IdA and Id corresponds to an error vector and cannot be a large value in an accident in the A region. Accordingly, when the relationship (13) is established between the absolute value of the difference between IdA and Id and the absolute value of Id, it is determined that an accident has occurred in the area A where the operation amount IdA is calculated.

IdA-Id ≦ k2 · Id... … (13)

(K2 is less than 1 coefficient)

6 shows a third embodiment, in which a phase comparison of Id and IdA is added to the characteristic principle vector diagram of FIG. 4. As described above, when an accident occurs in the area A, since IdA and Id are equal in terms of vectors, it can be said that the phases are almost the same in addition to the scalar amount. Accordingly, in addition to the formula (11), when the relationship of formula (14) is established again, it is determined that an accident has occurred in the area A where the operation amount IdA is calculated.

Id∧IdA ≦ α... … (14)

(α is a predetermined phase angle)

Fig. 7 shows the fourth embodiment, and a condition in which an upper limit is further added to the absolute value of IdA is added to equation (11) showing the relationship between the absolute value of Id and the absolute value of IdA. When an accident occurs in the area A, IdA and Id have almost the same value, so that the absolute value of IdA does not greatly exceed the absolute value of Id. Accordingly, the relationship of the following equation (15) is established between the absolute value of IdA and the absolute value of Id, and when equation (14) is established again, it is determined that an accident has occurred in the area A where the operation amount IdA is calculated.

k1 · Id ≦ IdA ≦ k3 · Id... … (15)

(k1 is a coefficient less than or equal to 1, k3 is a coefficient greater than or equal to 1)

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

Accordingly, by considering this sensitivity value (KTAP) as the lower limit value of the operation amount in the relation (11) between IdA and the absolute value of Id, it is possible to prevent transient malfunction in the initial stage of the accident in which the operation amount is small. Can be. The condition of Expression (16) is set as an AND condition with Expression (14), and not only the accident bus determination can be performed, but also the accident bus determination can be performed as the expression (17) in combination with the expression (15).

IdA ≧ K1 max {Id, KTAP}... … (16)

However, max {A, B} represents a large value of either A or B.

K1 · (max {Id, KTAP} ≦ IdA ≦ k3 · Id…… (17)

(k1 is a coefficient less than or equal to 1, k3 is a coefficient greater than or equal to 1)

Similarly, in order to set the lower limit of the operation amount, a method of using the sensitivity value (18) is also effective. In order to prevent erroneous detection in the small current region, there is a method of setting (19) by setting a value obtained by multiplying the sensitivity value KTAP by a predetermined coefficient as the lower limit of the operation amount IdA. The expression (19) is set as AND with the expression (13), whereby an accident bus determination can be made. In the above determination formula, by setting the expressions (13) and (16) under the AND condition, more reliable accident bus determination can be performed.

IdA? K1 (Id + KTAP)... … (18)

IdA≥K4KTAP... … (19)

(K4 is less than 1 coefficient)

Next, the case where the protection area is limited to two is considered. When an accident occurs in the area A of the two protection areas A and B, the operation amount of the area A is equal to the operation amount Id of the calculation means for collective protection as described above, but the operation amount IdB of the area B is generated at this time. Do not do it (only an error value).

As a condition for detecting that an accident has occurred in the area A, consideration is made between the absolute value of IdB and the absolute value of Id. However, in the case where the judgment of equation (20) alone does not occur in both A and B areas, an accident is issued in one of the areas to determine that an accident has occurred in the other area. You need to add it as long as it exists.

In addition to this condition (11) using the absolute value of the operating amount IdA and the absolute value of Id as the condition, it is determined that an accident has occurred in the area A when the condition is satisfied at the same time as the condition (20). . Similarly, the condition in which an accident occurs in the area B is determined by the establishment of both conditions of equations (21) and (22).

IdB ≦ K5 · Id... … 20

(K5 is less than 1 coefficient)

?? IdA ?? ≤K5 · ?? Id ?? … … (21)

?? IdB ?? ≥K1 · ?? Id ?? … … (22)

In the interruption bus determination unit 14, the interruption bus is judged by combining the internal / external accident determination output from the collective protection calculation unit 12 and the determination result of the accident bus determination unit 13. For example, when the calculation means for collective protection performs an internal accident determination, and the accident bus determination means outputs the accident determination of the area A, the interruption output to the line connected to the bus of the area A is activated. The determination of the interruption bus bar determination means 14 is collectively performed according to Table 1, whereby the interruption start of the accident occurrence area (accident busbar connection line) is performed.

In the description of the above embodiment, a bus bar system is taken as an example, but is not limited thereto. In other words, similar effects can be obtained as long as the system has a configuration composed of a plurality of protection areas to which protection by a differential calculation principle is applied.

Output of calculation means for collective protection Accident bus determination means output Break bus determination means output An internal accident A area A bus stop operation An internal accident B area A bus stop operation An internal accident A, B area A, B bus stop operation An internal accident none No shut-off maneuver An external accident A area No shut-off maneuver An external accident B area No shut-off maneuver An external accident A, B area No shut-off maneuver An external accident none No shut-off maneuver

As described above, according to the present invention, an operation amount calculated for determination and an operation calculated for each of the plurality of protection areas individually in a collective protection relay that performs internal and external accident determination for an area including a plurality of protection areas. The system has added an accident system determination function that can determine the protection area where an accident occurs by using the quantity. Therefore, it is possible to select and block an accident occurrence in a plurality of protection areas with a simple configuration without using a divided protection relay. Can provide a system protection relay device.

Claims (10)

In the system protection relay device which samples the electricity amount of the power system at predetermined time intervals, and uses the sampling data to identify the occurrence of an accident in a plurality of protection areas (sections) and performs the determination. First calculation means for calculating an operation amount and a suppression amount, and for distinguishing between internal and external accidents of the protection area including the plurality of protection areas (sections) by a predetermined ratio differential calculation; When the operation amount is calculated for each protection area individually, and any one of the absolute values of the operation amount calculated here is larger than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient, the condition is set. The system protection relay device which has a 2nd calculation means which establishes and detects that an accident generate | occur | produces in an individual protection area. The absolute value of the difference value between the operation amount calculated by the first calculation means and the operation amount calculated separately for the protection region is a value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient. And a second calculating means for detecting that an accident has occurred inside the protection area obtained when the value is smaller than the absolute value of the difference value. The method according to claim 1, wherein the following conditions a and b are simultaneously established between an operation amount calculated for each of the plurality of protection areas individually and an operation amount calculated by the first calculation means, so that an accident occurs inside the protection area. A system protective relay device comprising a second calculating means for detecting what is occurring. a. Any one of the absolute values of the operation amount calculated for each protection area is larger than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient. b. The phase difference between the operation amount of the protection area in which the condition a is satisfied and the operation amount calculated by the first calculation means is smaller than the predetermined angle among the operation amounts calculated for the protection areas individually. The system protection relay device according to claim 3, which is c condition shown below instead of a condition. c. Any one of the absolute values of the operation amount calculated for each protection area is larger than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient (coefficient less than 1), and the operation calculated by the first calculation means. It is smaller than the value obtained by multiplying the absolute value of the quantity by a predetermined coefficient (coefficient of one or more). The system protection relay device according to any one of claims 1, 3, and 4, wherein the absolute value of the operation amount calculated by the first calculation means is a value shown in d below. d. A large value of either the absolute value of the operation amount calculated by the first calculating means or the predetermined operation sensitivity value preset for the determination of the first calculating means. The system protection relay device according to any one of claims 1, 3, and 4, wherein an absolute value of the operation amount calculated by the first calculating means is a value shown in e below. e. A value obtained by adding a predetermined operation sensitivity value preset for the determination of the first calculation means to the absolute value of the operation amount calculated by the first calculation means. The absolute value of the difference between the operation amount calculated by the first calculating means and any one of the operating amounts calculated individually for the protection area is determined by applying a predetermined coefficient to the absolute value of the operating amount calculated by the first calculating means. It is smaller than the multiplied value, and the operation amount calculated for each of the protected areas where this condition is satisfied is higher than the value obtained by multiplying a predetermined value (value less than or equal to 1) by an operation sensitivity value preset for the determination of the first calculation means. It is large, The system protection relay apparatus characterized by including the 2nd calculating means which detects that an accident generate | occur | produces inside the said area | region. The method of claim 1, wherein the conditions f and g shown below are equally established between the operation amount calculated for each of the plurality of protection areas individually and the operation amount calculated by the first calculation means, thereby causing an accident inside the protection area. And a second calculating means for detecting that is generated. f. Either of the absolute values of the operation amounts calculated for each protection area individually is either the absolute value of the operation amount calculated by the first calculation means or the operation sensitivity value preset for the determination of the calculation result of the first calculation means. It is larger than the value multiplied by the predetermined coefficient. g. The absolute value of the difference between the operation amount calculated by the first calculation means and any one operation amount calculated by the protection area individually is smaller than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculation means by a predetermined coefficient. In the system protection relay device which samples the electricity amount of the power system at predetermined time intervals, and performs accident detection determination in two protection areas (sections) using these sampling data, the operation amount is used using the said sampling data. And first calculation means for calculating the amount of suppression and distinguishing between internal and external accidents of the protection area including the two protection areas (sections) by a predetermined ratio differential calculation, and the two protection areas separately. When the operation amount is calculated and one of the absolute values of the calculated operation amount is smaller than the value of the absolute value of the operation amount calculated by the first calculating means multiplied by a predetermined coefficient, an accident occurs in the other protection area. The system protection relay device characterized by including the 2nd calculating means which detects a thing. The method according to claim 9, wherein one of the absolute values of the operation amounts calculated for each of the two protection areas is larger than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined value, and the other. When the absolute value of the operation amount calculated in the protection area is smaller than the value obtained by multiplying the absolute value of the operation amount calculated by the first calculating means by a predetermined value, an operation amount larger than the operating amount calculated by the first calculating means is obtained. The system protection relay device characterized by including the 2nd calculating means which detects that an accident generate | occur | produces in a protection area.