JP2971329B2 - Bus protection relay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as a bus protection relay of this kind,
For example, there is a device disclosed in Japanese Patent Publication No. 63-50935, and FIGS. 10 and 11 show an embodiment of an analog bus protection relay device to which a conventional technique is applied. In FIG. 10, 1-1 to 1-4 are buses to be protected, 2-1 and 2-2.
Is a bus section disconnector (hereinafter referred to as section DS), 10
1, 201 ... 301, 401 ... are bus selection disconnectors (hereinafter, referred to as DS) for each line such as transmission lines and transformers, 3-1 to 3-1.
3-n, 4-1 to 4-n, 4-A to 4-D are current transformers (hereinafter referred to as CT), 5-1 to 5-n, 6-1 to 6-
n, 6-A to 6-D are input converters for respectively deriving outputs proportional to the CT secondary current.

[0003] 2-1X and 2-2X correspond to the class DS2-
.., 301X, 401X,..., 301X, 401X,...
, 301, 401... Are auxiliary contacts (hereinafter referred to as DS auxiliary relays) that operate in conjunction with the opening and closing of the DSs 101, 201,.
A collective bus protection relay (hereinafter, collectively referred to as a collective relay) that receives the output of 5-n and detects any of the accidents of the buses 1-1 to 1-4. 1
6-n and 6-A to 6-D, which are divided bus protection relays (hereinafter referred to as divided relays) for detecting an accident for each bus.

FIG. 11 shows a DC control circuit of the conventional device shown in FIG. 10, and although not shown, buses 1-1 to 1-4 are provided.
FIG. 2 is a basic configuration diagram of a trip command circuit for tripping a circuit breaker installed in each line such as a transmission line connected to a power line. FIG.
In 1, the contact 87 is a contact that is turned on when the collective relay 7 operates, and the contacts 87A1, 87B1, 87A2, 8
7B2 is a contact that turns on when each of the split relays 8-1 to 8-4 is operated, and 2-1X and 2-2X are the contacts of the segment DS2.
Reference numerals -1, 2-2 denote DS auxiliary relay contacts that are turned on when closed.

Next, the operation of the conventional device shown in FIGS. 10 and 11 will be described. In FIG. 10, the collective relay 7 is connected so as to operate even if an internal accident occurs in any of the buses 1-1 to 1-4 and not to operate outside the bus. That is,
The input converters 5-1 to 5-n receive the secondary currents CT3-1 to 3-n except for the bus ties for communication between the buses connected to the buses 1-1 to 1-4 at the input converters 5-1 to 5-n. Proportional to the secondary current)
The amount obtained by differentially connected to a (vector synthesis quantity) the operation input, although not shown CT3-1~3-n the input transducer were the absolute value proportional to the output 5-1～5- n, and the sum of the absolute value outputs (scalar synthesis amount) or the maximum value of the absolute value outputs is used as the suppression input as buses 1-1 to 1-4.
This is a ratio differential relay that determines whether an internal or external accident has occurred.

On the other hand, the split relays 8-1 to 8-4 have the same operating principle as that of the collective relay 7, but have the purpose of determining at which bus the accident has occurred.
-4 are provided for each of them. Therefore, the CT input needs to take in only the line connected to the corresponding bus, and the outputs of the input converters 6-1 to 6-n are connected to the DS auxiliary relay contacts 101X, 2
, 301X, 401X,...

[0007] The classification DS2-1 and 2-2 usually have C
Since T is not installed, the current flowing through the section DS becomes a differential error, and the split relay cannot make a normal determination. As a countermeasure, the detection range of the split relay is changed according to the open / close state of the section DS.
If S2-1 is closed and 2-2 is open, the section DS auxiliary relay 2-1X operates, and the a-contact is closed and the b-contact is opened. 8-
The input applied to 1 is switched to the side of the split relay 8-3 for detecting the accident of the second excavator 1-3 of the excavator 2. That is, the former 2 bus 1-
3 is integrated when the section DS2-1 is closed, so that the split relay switches the CT input accordingly, and the split relay 8-3
Protect the buses 1-1 and 1-3.

On the other hand, since the section DS2-2 is open, the section D
S auxiliary relay 2-2X becomes inactive, and Otsu 1 bus 1-2
The inputs of CT4-1 and 4-B inserted into the connection line of No.1 are introduced into the split relay 8-2 for Otsu1 so that Otsu2 bus 1-4
The inputs of CT4-n and 4-D inserted into the connection line of (1) are introduced into the split relay 8-2, so that the buses 1-2 and 1-4 are independently protected.

The conditions for detecting a bus fault and issuing a trip command to the circuit breaker with the above configuration are shown in FIG. FIG.
The configuration of the trip command circuit shown in FIG. 7 is a contact 87 that is turned on when the collective relay 7 is operated and contacts 87A1, 87B1, 87A2, and 87B2 that are turned on when the divided relays 8-1 to 8-4 are operated.
Is a so-called batch split double protection system having an AND configuration, and a section DS auxiliary relay contact 2-1X, 2-2X is added to the above-mentioned section DS countermeasure when the section DS is closed. The bus is connected and cut off.

[0010]

A disconnector is installed in the bus section (CT is not installed).
In a double-bus configuration in which is open / closed arbitrarily, a bus protection relay capable of appropriately changing the protection range according to the open / closed state of the section DS has conventionally adopted the analog type as described above, If this is replaced with a digital form, the following problems occur.

(1) Problems in CPU calculation processing time If an attempt is made to replace the bus protection relay as shown in FIG. 10 with a digital type, the input converter and subsequent parts will be digitized. Therefore, when the conventional dual system in which the collective unit and the split unit are separate hardware is adopted, one unit for the collective digital relay (corresponding to the conventional collective relay 7) and one split digital relay (the conventional split relay 8-1) are used. 1 to 8-4).

In such a configuration, as the digital relay for splitting, the relay operation for four split relays and the secondary output switching process of the input converter (contact 1 in FIG. 10) are performed.
01X, 201X ..., 301X, 401X ..., 2-1
X, output switching by 2-2X) and the amount of differential,
Although data processing such as suppression amount derivation is required, there is a limit to the bus configuration that can be handled due to the performance in CPU processing time. Note that in the example of FIG.
There is also a bus configuration with more S divided into 6 and 8 divisions.
The number of lines connected to the bus will also increase, but a device that can flexibly cope with them will be required.

(2) It is difficult to use a plurality of division digitals. As a countermeasure of the above item (1), the number of division digital relays is increased according to the bus scale, or the digital relays are multi-CPU type and distributed processing is performed. However, it is not easy to cope with the problem because the performance of the bus protection relay is reduced or the cost is increased.

For example, the split relays 8-1 and 8- in FIG.
2 is divided into one digital relay (or CPU), and the division relays 8-3 and 8-4 are divided so as to be processed by another digital (or CPU).
When the -1, 2-2 is closed, the CT input data for the split relays 8-1 and 8-2 is divided into the
-3, 8-4. This data transfer is an important performance of the bus protection relay in terms of countermeasures against CT saturation (operation determination is made within the unsaturated time until the current waveform crosses zero and saturation starts, and the determination result is stored during the saturation section. This process is repeated every half cycle.) It is necessary to complete the processing within a very short time (sampling cycle, for example, within 30 electrical degrees), but transfer or transfer a large amount of current data between the two digital relays. If the transfer is performed after pre-processing the derivation of the differential amount suppression amount, it takes too much time to achieve the above performance. Further, even if special hardware is prepared for high-speed transfer of a large amount of data, it will lead to a large increase in cost, and it is difficult to achieve the above-mentioned correspondence.

The present invention has been made in order to easily solve the above-mentioned problems, and it is possible to install a digital relay for division in an arbitrary bus unit, and it is not necessary to transfer current data between the digital relays. Accordingly, it is an object of the present invention to obtain a digital bus protection relay having a new division protection system which prevents a reduction in the performance of the division relay against CT saturation and prevents an increase in cost required for data transfer.

[0016]

A bus protection relay according to the present invention comprises a plurality of buses each having a bus segment disconnector and a circuit in which a line connected to a generator, a load, or the like is connected to the bus.
For a path, a current or current / voltage of this circuit is derived and converted into a digital quantity, and is subjected to arithmetic processing by a predetermined program, and a bus protection relay device for protecting the bus according to the processing result. A collective bus protection relay of a differential system that calculates based on the derived digital amount and collectively detects the plurality of bus faults, and a differential that calculates based on the derived digital amount and detects each bus fault individually. -Type split bus protection relay, a differential direction relay that operates based on the derived digital quantity, determines the current direction of each bus, and operates in accordance with the outflow direction of the current, and the collective bus protection Means for outputting a logical product output of the relay output and the divided bus protection relay output of each bus unit as a trip command output of each bus unit; Among the directional relays for a double busbar sandwiching the road device, in which with a trip command circuit having a means for preventing trip command output corresponding to the two bus bars in accordance with one of the operation.

Further, the direction relay provided for each busbar unit is as follows:
At least one of a short-circuit direction relay, a ground fault direction relay, and a direction distance relay is used.

The directional relay is a relay that operates according to a current change of each bus before and after the accident.

Also, a plurality of buses having a bus section disconnector and a line connected to a generator, a load, etc. are connected to the bus.
The current and voltage of this circuit are derived, converted into digital current / voltage data, processed by a predetermined program, and a bus protection relay for protecting the bus according to the processing result. An electrical device, wherein a sum of instantaneous current values of current data corresponding to the plurality of buses is set as an operation amount, and a collective bus for performing ratio differential operation with the sum of instantaneous absolute values of the current data or the maximum value of the instantaneous absolute values as a suppression amount. The protection relay, the current bus instantaneous value sum of each bus unit as an operation amount, and the ratio bus differential division bus of each bus unit for performing ratio differential operation with the instantaneous absolute value sum or the maximum instantaneous value absolute value of the current data as the suppression amount The protection relay uses the instantaneous value of the bus voltage data in each bus unit as a reference amount, performs direction discrimination calculation using the instantaneous value sum of the current data in each bus unit as a comparison amount, and operates the comparison amount according to the outflow direction from each bus. Means for outputting a logical product output of the short-circuit direction relay of each bus unit, the output of the collective bus protection relay and the divided bus protection relay output of each bus unit as a trip command output for each bus unit, and when the bus segment disconnector is closed, A trip command circuit having means for preventing trip command output corresponding to both buses in response to operation of one of the direction relays corresponding to both buses sandwiching the bus segment disconnector. is there.

The short-circuit direction relay is a ground fault direction relay. The ground fault direction relay derives a zero-phase voltage data instantaneous value of each bus unit and sets it as a reference value, and a zero-phase current data instantaneous value of each bus unit. This is a ground fault direction relay that derives the effective component of the sum and uses it as a comparison amount.

Also, a plurality of buses having a bus section disconnector and a line leading to a generator, a load, etc. are connected to the bus.
A bus protection relay device for deriving the current of this circuit , converting the current into digital current data, performing arithmetic processing with a predetermined program, and protecting the bus according to the processing result. A total bus instantaneous value sum corresponding to the plurality of buses as an operation amount, and a collective bus protection relay for performing a ratio differential operation using the instantaneous absolute value sum of the current data or the maximum value of the instantaneous absolute value as a suppression amount; An operation amount is a sum of instantaneous values of current data in bus units, and a division bus protection relay for each bus unit for performing ratio differential operation using the sum of instantaneous absolute values of the current data or the maximum value of the instantaneous absolute values as a suppression amount. Using the collective differential amount derived by vector-synthesizing the current data corresponding to the bus as a reference amount, the direction discrimination operation is performed using the instantaneous sum of the current data of each bus as a comparison amount, and the comparison amount is determined as the outflow direction from each bus. A short-circuit direction relay for each bus unit that operates in response to the logical product output of the output of the collective bus protection relay and the output of the divided bus protection relay for each bus unit as a trip command output for each bus unit; Means for preventing trip command output corresponding to both buses in response to operation of one of the directional relays corresponding to both buses sandwiching the bus segment disconnector when the device is closed. It is provided with.

The short-circuit direction relay is a ground fault direction relay, and the ground fault direction relay has a reference amount as a collective zero-phase differential amount,
The relay is used as the sum of the instantaneous values of the zero-phase current data of each line in each bus unit according to claim 5.

The collective bus protection relay is a collective differential voltage amount derived by synthesizing current data corresponding to a plurality of buses in parallel, and detects the level of the collective differential voltage amount. In addition to the relay, the short-circuit direction relay or the ground fault direction relay is a relay that uses the instantaneous value of the collective differential voltage amount as a reference value.

Further, the short-circuit direction relay or the ground fault direction relay has the following relationship from the reference amount (V) and the comparison amount ( _ID ): | V | · | Z _S · _ID Δφ |> 0 (where Z _S , Φ are constants, and I _D ∠φ is a directional distance relay that operates according to the determination of I _D ∠φ phase shift.

The short-circuit or ground-fault directional relay or directional distance relay is a relay whose comparison value is an amount corresponding to a change in the instantaneous sum of current data in each bus unit before and after the occurrence of the accident. It is.

[0026]

The bus protection relay device according to the present invention detects a plurality of bus faults collectively with a collective bus protection relay, detects faults for each bus with a split bus protection relay, and detects a current for each bus with a direction relay. Each direction is determined. In addition, the trip command circuit outputs the logical product output of the collective bus protection relay output and the divided bus protection relay output of each bus unit as a trip command output of each bus unit. The trip command output corresponding to both buses is blocked according to the operation of one of the directional relays corresponding to both buses sandwiching the disconnector.

The directional relays provided for each bus unit are:
At least one of a short-circuit direction relay, a ground fault direction relay, and a direction distance relay is used.

The direction relay operates according to a change in the current of each bus before and after the accident.

Also, the collective bus protection relay uses the instantaneous sum of current data corresponding to a plurality of buses as an operation amount, and the sum of instantaneous absolute values of the current data or the maximum value of the instantaneous absolute value as a suppression amount. The split bus protection relay calculates the sum of the instantaneous value of the current data in each bus unit as an operation amount, and performs a ratio differential operation using the sum of the instantaneous value absolute values of the current data or the maximum value of the instantaneous value absolute value as a suppression amount, The short-circuit direction relay of each bus unit uses the instantaneous value of the bus voltage data of each bus unit as a reference amount and performs direction discrimination calculation using the sum of the instantaneous value of the current data of each bus unit as a comparison amount. Operates according to direction. The trip command circuit outputs a logical product output of the collective bus protection relay output and the divided bus protection relay output of each bus unit as a trip command output of each bus unit. The trip command output corresponding to both buses is blocked according to the operation of one of the directional relays corresponding to both buses sandwiching the disconnector.

The short-circuit direction relay is a ground fault direction relay. The ground fault direction relay derives an instantaneous value of zero-phase voltage data for each bus unit and sets it as a reference value. The effective component of the sum is derived and used as the comparison amount.

The collective bus protection relay uses the instantaneous sum of current data corresponding to a plurality of buses as an operation amount and the sum of instantaneous absolute values of the current data or the maximum value of the instantaneous absolute values as a suppression amount. The split bus protection relay calculates the sum of the instantaneous value of the current data in each bus unit as an operation amount, and performs a ratio differential operation using the sum of the instantaneous value absolute values of the current data or the maximum value of the instantaneous value absolute value as a suppression amount, The short-circuit direction relay of each bus unit performs a direction discrimination operation using the collective differential amount derived by vector-synthesizing the current data corresponding to a plurality of buses as a reference amount, and the instantaneous sum of current data of each bus unit as a comparison amount, This comparison amount operates according to the outflow direction from each bus. Also,
The trip command circuit outputs a logical product output of the collective bus protection relay output and the divided bus protection relay output of each bus unit as a trip command output of each bus unit. The trip command output corresponding to both buses is blocked in accordance with the operation of one of the direction relays corresponding to both buses sandwiching.

In addition, the short-circuit direction relay is a ground fault direction relay, and the ground fault direction relay has a reference amount as a collective zero-phase differential amount,
The comparison amount is the instantaneous value sum of each line zero-phase current data in each bus unit according to claim 5.

The collective bus protection relay is a collective differential voltage amount derived by synthesizing current data corresponding to a plurality of buses in parallel. The collective differential voltage amount level is detected, and the short-circuit direction relay or ground fault is detected. The direction relay uses an instantaneous value of the collective differential voltage amount as a reference value.

Further, short-circuit direction relay or ground direction relay and the reference quantity (V), compared the amount of _{(I D) | V | ·} | Z S · I D ∠φ |> 0 ( where, Z _S , Φ are constants, and I _D ∠φ is a directional distance relay that operates according to the discrimination of I _D ∠φ phase shift).

The short-circuit or ground-fault directional relay or the directional distance relay uses the amount corresponding to the change in the instantaneous value of the current data in each bus unit before and after the occurrence of the accident as the comparison amount.

[0036]

【Example】

Embodiment 1 FIG. One embodiment of the present invention will be described with reference to FIG. In the drawings, the same or corresponding parts as those in FIG. 10 are denoted by the same reference numerals. In FIG. 1, 9-1 to 9-4
Is an instrument transformer (hereinafter, referred to as PT) connected to each of the buses 1-1 to 1-4, and PT-1 to PT-4 are PT9.
An input converter 11 for deriving a voltage proportional to a secondary voltage of -1 to 9-4, and 11 corresponds to a conventional batch relay (87) 7 which operates by receiving outputs of the input converters 5-1 to 5-n This is a batch digital relay.

12-1 are input converters 6-1..., 6-A,
The conventional split relay (87
A1, 87B1) Portions corresponding to 8-1, 8-2 and input converters 10-1, 10-2 and 6-1 ..., 6-A, 6-
Direction relays 67A1, 67B that operate in response to the output of B
This is a division digital relay that calculates 1. 12-2 is a portion corresponding to conventional split relays 8-3 and 8-4 which operate by receiving the outputs of the input converters 6-n..., 6-C and 6-D;
Input converters 10-3, 10-4 and 6-n ..., 6-
Direction relay 67A that operates upon receiving the outputs of C and 6-D
2, 67B2.

87X, 87A1X to 87B2X, 67A
1X to 67B2X are output relays, respectively.
X is ON when the section DS2-1 is closed, and the contact 2-2X is 2-2.
Is turned ON when closed, 67A1X and 67A2X or 6
7B1X and 67B2X are configured to operate in a linked manner.

The internal configurations of the collective digital relay 11 and the divided digital relays 12-1 and 12-2 are almost the same, and a general basic configuration example is shown in FIG. In the figure, filters 13-1 to 13-n receive CT and PT inputs via input converters, and
Through 4-1 to 14-n, multiplexer 15, and A / D converter 16, an instantaneous digital value sampled at the same time and at the same interval is obtained. Reference numeral 17 denotes a digital input unit (DI) for receiving a contact input, reference numeral 18 denotes a memory, and reference numeral 19 denotes a CP.
U and 20 are digital output units (DO).

The operation principle will be described below. The operating principle of the collective digital relay 11 is the same as that of the conventional collective relay 7, and since the divided digital relays 12-1 and 12-2 are equivalent, they will be represented by the divided digital relay 12-1 in the following detailed description. FIG. 3 is a conceptual diagram of the relay arithmetic processing performed by the CPU of the split digital relay 12-1. In the figure, current data I _{1 to} In, I _A1 ,
I _B1, the voltage data V _A1, V _B1 Each input converter connected to the bus 1-1,1-2 6-1 ..., 6-A, 6-B,
10-1 and 10-2, instantaneous value digital data and contact input data 101X to 1nX, 201X to 2
nX is DS10 connected to buses 1-1 and 1-2, respectively.
1, 201... Are the ON-OFF data of the auxiliary relay contacts, and the following relay calculation is performed using these data.

The selection process 111 is performed for each line current data I _1-
In represents contact input data 101X to 1nX and 201X to 2
Select the first party or the second party in accordance with the ON / OFF condition of nX. For example, when the line of CT4-1 in FIG. 1 is connected to the first party bus 1-1, DS101 is closed.
Since the DS 201 is open, the DS auxiliary relay contact 101X is turned ON, 201X is turned OFF, and the CT4-1 current data I ₁ is selected for the first party.

Next, reference numerals 112 and 113 denote current data processing of the first party group and the second party group, and derive a differential amount and a suppression amount using the current data selected in the selection processing 111. That is, in the first party current data processing 112, all the instantaneous value data of the line connected to the first party bus are added to obtain the first _party differential _IDA1, and the absolute value of each instantaneous value data is calculated. Then, a process is performed to derive the total addition value or the maximum value of the calculated values and to obtain the first _party suppression amount | _IRA1 |. Similarly, the second party current data processing 113 performs the second party bus processing.

Reference numeral 114 denotes an instep 1 split relay (87A1), 1
Reference numeral 15 denotes a relay calculation process of the second party split relay (87B1). For example, in the calculation process 114 of the first party split relay (87A1), the first party differential amount I _DA1 and the first party suppression amount |
I _RA1 | the ratio differential relay computation formula | I _DA1 | -η | I
An operation determination is made based on the basic principle of _RA1 |> K (where η and K are constants).

[0044] 116 and 117 are short-circuited direction relay computation instep 1 and Party B 1, for example, the upper 1 short direction relay computation 116, the reference quantity voltage data V _A1 of the upper 1 bus 1-1, wherein the upper 1 The direction discrimination is performed using the differential amount I _DA1 as a comparison amount. Incidentally, well commonplace as determination principle, for example, V _A1T1 the V _A1, I _DA1 data at time T1, I _DA1T1, time T1 electrical angle of 90 ° before the V _A1 from the I _DA1 data V _A1T2, I if _{DA1T2 V A1T1 · I DA1T1 + V} A1T2 · I DA1T2 = V A1 sinωt · I DA1 sin (ωt-θ) + V A1 c
osωt · I _DA1 cos (ωt−θ) = | V _A1 | · | I _DA1 | cos θ (where θ is the phase angle between V _A1 and I _DA1 ), so that V _A1T1 · I _DA1T1 + V _A1T2 · I _DA1T2 > 0 Is determined, the phase angle θ of I _DA1 with respect to V _A1 is ± 90.
Since it is possible to detect whether it is within ゜, the direction can be determined with this.

Next, a trip command circuit composed of a combination of the relay outputs calculated by the CPU will be described with reference to FIG. Each relay determination result as the CPU operation result shown in FIG. 3 is output via the digital output unit (DO) 20 shown in FIG. 2 to the output relays 87A1X, 87B1X, and 67A1 shown in FIG.
X, 67B1X are driven.

On the other hand, the split digital relay 12-2 and the collective digital relay 11 also have their output relays driven in the same manner, and these output relay contacts are combined as shown in FIG. 21
-1 to 21-4 are output. FIG. 4 is equivalent to FIG. 11 of the related art, but short-circuit direction relays 67A1 to 67B2.
The difference is that the b contacts 67A1X to 67B2X that are released during operation are inserted. This, as explained above,
When the section DS2-1 or 2-2 is closed, the split relay 87
A1, 87A2 or 87B1, 87B2 is prevented from malfunctioning due to an external accident and tripping to a healthy bus.
In combination with the X condition, when one of the directional relays of both buses sandwiching the section DS is operated when the section DS is closed, both buses are shut off and locked.

The above operation principle will be described in more detail with reference to FIG. FIG. 5 shows an example of a current distribution in a case where the sections DS2-1 and 2-2 are in a closed state and an internal accident has occurred at the point F1 of the Exhibit 2 Bus 1-3 and an accident has occurred in the external F2 point. I have. First, in the case of F1 point fault, the fault current is _{I 1, I 2, I 6} , I 7 flows toward the supply end to the fault point F1, collectively differential amount I _D is _{I 1 + I 2 + I 6} + I 7 In the inflow direction with respect to the bus, the divided differential amount I _DA1 of the first line 1-1 is I ₁ + I ₃ , and the inflow direction, the divided differential amount I _DB1 of the _second line 1-2 is I ₂ −I ₃ . Is inflow direction because of I ₂ > I ₃ , Instep 2
The divided amount I _DA2 of the bus 1-3 is I ₆ + I ₈ ,
I _DB2 of Otsu 2 Bus 1-4 is I ₇ -I ₈ , which is the outflow direction because I ₈ > I ₇ .

Accordingly, the collective relay and the split relay are all in operation because the differential amount is generated.
Since split differential I _DB2 of Party B 2 bus 1-4 outflow direction Otsu 2
The short-circuit direction relay 67B2 operates, and as described above, the 67B2
The X and 67B1X operations result in the contact 67B1 of FIG.
X and 67B2X are opened, the breaker trip command to the second bus and the second bus are blocked, and only the first and second buses on the accident side are cut off.

Next, in the event of an external accident at point F2, the collective differential amount I
_D is I ₁ + I ₂ + I ₆ + I ₇ −I ₉ = 0 and the collective relay does not operate, but the divided differential amounts I _DA1 , I _DA2 , I _DB1 , and I _DB2 are currents flowing to the sections DS2-1 and DS2-2. I ₄ and I ₅ are generated as errors, and all the split relays operate. On the other hand, the divided differential amounts I _DA1 , I _DA2 , I _DB1 ,
Direction I _DA1 and I _DB1 of I _DB2, for I _DB2 is the F1
As at the time of the accident, I _DA2 is I ₆ + I ₈ -I ₉ and I ₉ > I ₆ + I
It said Party B 2 short direction relay 67B2 and instep 2 short direction relay 67A2 for the outflow direction for ₈ will be to operate, in which acts trip blocking due to a short circuit direction relay for all bus after all. Since the bus voltage used as the reference value of the short-circuit direction relay becomes zero at the time of a bus fault and the direction cannot be determined, as a countermeasure, a voltage several cycles before the occurrence of the fault is stored in a memory and stored in the memory. The determination may be made using the applied voltage, and after the operation is determined, the determination may be maintained for a predetermined time.

As described above, the directional relay has the bus section D
When S closes, the current flowing here becomes a differential error (operation amount), and has the effect of preventing tripping to a healthy bus due to malfunction of the split relay. That is, the direction relay uses the bus voltage as the reference amount and the divided differential amount for each bus as the comparison amount, but compares the polarities of the respective divided differential amounts at both buses sandwiching the section DS. In the event of an external accident, the difference is discriminated from the bus because one is always in the inflow direction and the other is in the outflow direction. If it is greater than or equal to the value, it is determined that an external accident has occurred, and both buses can be trip-locked.

Therefore, the division digital relay is divided into the division DS.
Can be divided and installed in units of the insteps and the sub-buses separated by, and it is easy to cope with a large-sized bus such as a six-divided bus or an eight-divided bus.

Further, since the input of the direction relay can be obtained for each bus, the current data transfer between the divided digital relays becomes unnecessary, and special high-speed data transfer hardware is not required and the apparatus is inexpensive. become.

When the section DS is closed, the batch relay and the direction relay are used. However, when the section DS is open, since the split relay has no extra processing such as data transfer, the processing time is high, and the CT saturation countermeasures are taken. Highly reliable division protection is maintained without a decrease in performance or the like.

Embodiment 2 FIG. In the above embodiment, the short-circuit direction relay is used for short-circuit bus protection, but this can be replaced with a ground fault direction relay for ground-fault bus protection. That is, although not shown, the PTs 9-1 to 9-
4 is provided with a tertiary circuit.
-1 through 10-4 each digital relay 12-
1, 12-2, and the zero-sequence voltage data of each bus unit obtained by conversion into a digital quantity is used as a reference quantity, or
The CPU uses the zero-phase voltage data obtained by performing a three-phase vector synthesis operation on the bus-unit secondary voltage data as a reference amount, and uses the CTs for protection of division 4-1 to 4-n and 4-A to 4-D.
Input converters 6-1 to 6-n, 6-A from the secondary residual circuit of
6-D, each divided digital relay 12-1, 1
Introduced into 2-2, the effective part of the zero-phase divided differential current obtained by adding the instantaneous value of each line to the zero-phase current data obtained by converting it into a digital quantity is used as a comparison amount. A ground fault direction relay is applied.

In the event of a single-line ground fault in a high-resistance grounded cable system, the cable charging current and the NGL current (the charging current flowing through the capacitance of the cable is compensated by a reactor installed between the neutral point of the transformer and the ground). If the phase difference between the zero-phase voltage and the zero-phase-divided differential current becomes large if the zero-phase current is used as it is, the direction discrimination may be erroneous, but this is proportional to only the NGR current. If the zero-phase effective component differential current is used, there is no misjudgment because the current is always the same or opposite to the zero-phase voltage.

The direction discriminating method using the zero-phase effective differential current will be described below. The zero-phase voltage data V
_O and zero-phase split differential current data at time T1 of the data I _DO V _OT1, I _DOT1 the electrical angle 90 than the time T1
If ° the previous data with the _{V OT2, I DOT2 V OT1 ·} I DOT1 + V OT2 · I DOT2 = V O sinωt · I DO sin (ωt-θ) + V O cos
_{ωt · I DO cos (ωt-} θ) = | V O | · | the cosθ (but θ phase angle of V _O and I _{DO is) V OT1 · I DOT1 + V} OT2 · I DOT2> 0 because it is a | I _DO If it is determined, the direction is determined whether the phase angle θ of I _DO with respect to V _O is within ± 90 °, and | I _DO | c
Since osθ is active current of zero-phase differential current I _D, V if _{OT1 · I DOT1 + V OT2 ·} I DOT2> K ( where K is a constant), the zero-phase active component difference of the zero-phase voltage and the phase direction It is determined that the dynamic voltage is equal to or higher than the level K. As described above, according to this embodiment, ground fault protection can be performed with the same configuration as that of the short-circuit direction relay system, and there is an effect that countermeasures against reactive component current peculiar to the high-resistance ground cable system can be performed.

Embodiment 3 FIG. In the first embodiment, the bus voltage is used as the reference amount of the direction relay. However, this may be an amount proportional to the collective differential current, and FIG. 6 shows an embodiment thereof. FIG.
1 is that the tertiary coil 23 is provided in the transformer 22 of the collective input converters 5-1 to 5-n and all the output terminals are connected in series. To the divided digital relays 12-1 and 12-1
-2 and converted to a digital quantity.

Since the input converter for the CT circuit is originally configured to derive a secondary voltage proportional to the primary current, another voltage proportional to the primary current can be easily obtained by adding a transformer tertiary coil. The amount obtained by connecting this voltage in series for all lines is proportional to the collective differential current. Further, as described as the collective differential amount _ID at the time of the F1 point accident in FIG. 5, since this amount is always in the inflow direction with respect to the bus when it occurs, it can be used as the reference amount for the direction relay. Unlike the bus voltage, which occurs at the time of an accident, there is an advantage that the countermeasure for eliminating the reference amount as described above becomes unnecessary.

If the sections DS2-1 and 2-2 are closed, a normal load current passing therethrough is generated as an error-divided differential quantity. Operates, and if an accident occurs inside the bus from this state, there is a disadvantage that the shut-off time is delayed until the short-circuit relay returns.However, since the collective differential amount does not always occur, If it is used as an amount, it does not operate constantly and has the effect of eliminating the above-mentioned disadvantages. At the time of an accident outside the bus, the direction cannot be determined because there is no collective differential amount. However, in this case, since the collective relay 87 is always inoperative, there is no erroneous interruption without relying on this directional relay.

When this embodiment is applied to the second embodiment,
The ground-fault directional relay uses the CT3-1 as the reference value in place of the instantaneous value of the zero-phase voltage data for each bus in the second embodiment, in the same manner as the collective differential value derivation in the third embodiment.
The instantaneous values of the zero-phase collective differential amount derived from the residual circuits of .about.3-n are used. The effective component of the instantaneous value sum of each line zero-phase current data in bus units may be used.

Embodiment 4 FIG. In this embodiment, the batch relay of the current differential system of the first embodiment is changed to a voltage differential system, and the differential voltage is used as a reference amount of the direction relay. FIG. 7 is different from the embodiment of FIG. 6 in that the collective relay input converters 5-1 to 5-n provided for each line are omitted, and the collective protection CTs 3-1 to C-C are omitted.
The secondary circuit of T3-n is directly connected in parallel, and an abnormal condition including an input converter 25 having a large input impedance, a saturable reactor for suppressing the CT secondary voltage to a predetermined value or less, a nonlinear resistance element, and the like is connected to this circuit. A voltage suppression circuit 24 is provided to input the output voltage of the input converter 25 to the collective digital relay 11 and the divided digital relays 12-1 and 12-2.

Since the voltage differential method is a well-known principle, the description is omitted, but this differential voltage is used as the reference amount of the directional relay as in the third embodiment. Since it is not necessary to provide an input converter for each reference line to obtain the reference amount, there is an effect that the apparatus can be manufactured at low cost.

When this embodiment is applied to the second embodiment,
As the collective digital relay, the collective digital relay of the voltage differential system according to the third embodiment is used. Ground fault direction relay
As the reference amount, the instantaneous value of the collective differential voltage amount of the fourth embodiment is used instead of the zero-phase voltage data instantaneous value of each bus unit of the second embodiment. Instead of the instantaneous sum of the line current data of each bus unit, the effective portion of the instantaneous sum of the line zero-phase current data of each bus unit in the second embodiment may be used.

Embodiment 5 FIG. In this embodiment, the directional relays of the first and second embodiments are replaced by directional distance relays. FIG. 8 shows the embodiment. Figure 8 is a characteristic example of applying the principle of a known motor-shaped distance relay, voltage vector V corresponding to the reference amount of the directional relay is bus voltage V _A1 of FIG. 3, for example, the vector I _D Is a current corresponding to the comparison amount of the direction relay, for example, I _DA1 in FIG.
The vector V ₁ = Z _S・_ID ∠θ is obtained by multiplying the vector _ID by the settling constant Z _S and shifting the phase angle θ (90 ° in the example in the figure), and the vector V ₂ = V ₁ -V If the angle θ formed between the vector and the vector V is within 90 °, the operation is performed.

There are various calculation methods, for example, the following. V and V ₂ data at time T1 are converted to V _T1 and V
_2T1, V of an electrical angle of 90 ° before the time T1, the V ₂ data V
If _{T2, V 2T2 V T1 · V} 2T1 + V T2 · V 2T2 = Vsinωt · V 2 sin (ωt-θ) + Vcosω
Since t · V ₂ cos (ωt−θ) = | V | · | V ₂ | cos θ (where θ is the phase angle between V and V ₂ ), it is determined that V _T1 · V _2T1 + V _T2 · V _2T2 > 0. Then, it is detected whether or not the V ₂ phase angle θ with respect to V is within ± 90 °, so that the Moh-type distance relay characteristic 108 as shown in FIG. 8 can be obtained.

With such characteristics, it is possible to stop the operation with the load current at all times, and it is possible to obtain the effect of eliminating the above-mentioned delay time of interruption in an internal accident. That is, characteristic 1
08 can be changed by a constant Z _S for setting the size of the circle and a constant ∠θ for setting the maximum sensitivity angle. Therefore, when the section DS is closed, the differential current proportional to the load current passing therethrough is obtained. By setting so as to avoid the existence range of _ID , there is an effect that can be easily dealt with. In the event of a bus fault, the voltage V becomes zero and the operation cannot be determined.As a countermeasure against this, a voltage several cycles before the occurrence of the fault is added as a memory voltage, and this voltage is maintained for a predetermined time after the determination operation. Good.

Embodiment 6 FIG. In this embodiment, as the comparison amount of the directional relay or the directional distance relay of the above-described embodiment, the divided differential amount for each bus is used. An embodiment is shown in FIG.

When the section DS is closed, the load current flowing there always occurs as a divided differential amount. Therefore, if the bus voltage is used as the reference amount of the short-circuit direction relay or short-circuit direction distance relay, There is a case where the external direction is always determined and the operation state is set. If an accident inside the bus occurs in this state, the circuit breaker trip is locked until the directional relay or the directional distance relay changes to the internal accident judgment and returns, so that the interruption time is delayed. In this embodiment, in order to solve this drawback, the divided differential amount used for the operation determination is set to a change value before and after the occurrence of the accident.
This will be described in detail with reference to FIG.

In the figure, reference numeral 118 denotes the divided differential amount I derived in the first or second party current data processing 112, 113.
_DA1, shows a variation derivation process for deriving the variation from I _DB1, the method, for example, time T1 transient data (accident) I _DA1T1, time, for example, one cycle before data (normally) from T1 and I _{DA1T2 Is} used to calculate I _DA1T1 −I _DA1T2 . If the direction is discriminated within one cycle using this change, the change value before and after the occurrence of the accident, that is, the amount proportional to the accident current, is calculated. A directional relay that only operates will be obtained. It should be noted that if the result is held for a predetermined time after the judgment, it is possible to cope with a long accident continuation time.

In the above example, the direction discrimination is performed by using the comparison amount of the directional relay and the direction distance relay as the divided differential amount change value. Instead, the change level of the divided differential amount change value is detected. Then, this determination result may be inserted under an AND condition (for example, an AND condition of the output of 67A1 in FIG. 9 and the determination result of the variation deriving process 118). The effect is obtained.

[0071]

As described above, according to the present invention, a directional relay or directional distance relay for each bus is newly added to prevent erroneous shutoff, so that data transfer between divided bus relays becomes unnecessary. Thus, a responsive digital bus protection relay can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a digital bus protection relay according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing the internal configuration of the digital relay according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a calculation process of the divided digital relay according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a trip command circuit according to the first embodiment of the present invention.

FIG. 5 is a current distribution diagram for explaining the operation of the directional relay according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram of a digital bus protection relay according to Embodiment 3 of the present invention.

FIG. 7 is a configuration diagram of a digital bus protection relay according to Embodiment 4 of the present invention.

FIG. 8 is a characteristic diagram according to a fifth embodiment of the present invention.

FIG. 9 is a diagram illustrating a calculation process according to a sixth embodiment of the present invention.

FIG. 10 is a configuration diagram of a conventional analog bus protection relay.

11 is a configuration diagram of the circuit breaker trip command circuit of FIG.

[Explanation of symbols]

1-1 to 1-4 Protected buses, 2-1 and 2-2 bus segment disconnectors (section DS), 2-1X, 2-2X sectional disconnector auxiliary relay contacts (section DS auxiliary relay contacts), 3- 1
-3-n, 4-1 to 4-n, 4-A to 4-D Current transformer (CT), 5-1 to 5-n, 6-1 to 6-n, 6-A to
6-D, 10-1 to 10-4 input converter, 11 batch digital relay (batch bus protection relay), 12-1,
12-2 Split digital relay (split bus protection relay), 22 transformer in input converter, 23 transformer tertiary coil, 24 abnormal voltage suppression circuit, 25 high input impedance input converter, 101, 201, 301, 40
1 bus selection disconnector (DS) 108 Mo type distance relay characteristics, 111 selection processing unit,
112 First party current data processing, 113 First party current data processing, 114 First party split relay calculation processing, 115
Otsu 1 split relay operation process, 116 A1 short circuit direction relay operation process, 117 Otsu 1 short circuit direction relay operation process, 1
18 Change derivation processing.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ identification symbol FI H02H 3/40 H02H 3/40 E 7/22 7/22 A (58) Investigated field (Int.Cl. ⁶ , DB name) H02H 7/22-7/30 H02H 3/32-3/52

Claims (10)

(57) [Claims] A plurality of buses having a bus segment disconnector;
The line leading to the generator, load, etc. was connected to the bus
For a circuit, a bus protection relay that derives the current or current / voltage of this circuit and converts it into a digital quantity, performs arithmetic processing with a predetermined program, and protects the bus according to the processing result. A collective bus protection relay of a differential system that calculates based on the derived digital quantity and collectively detects the plurality of bus faults. A differential that calculates based on the derived digital quantity and detects the fault for each bus. -Type split bus protection relay, a differential direction relay that operates based on the derived digital amount, determines the current direction of each bus, and operates according to the outflow direction of the current, the collective bus protection Means for outputting a logical product output of the relay output and the divided bus protection relay output of each bus unit as a trip command output of each bus unit; A trip command circuit having means for blocking trip command output corresponding to both buses in response to operation of one of the directional relays corresponding to both buses sandwiching the divided disconnector. Bus protection relay device. 2. The bus according to claim 1, wherein the directional relay provided for each bus uses at least one of a short-circuit directional relay, a ground fault directional relay, and a directional distance relay. Protection relay. 3. The bus protection relay according to claim 1, wherein the direction relay is a relay that operates according to a current change of each bus before and after the accident. 4. A plurality of buses having bus segment disconnectors,
The line leading to the generator, load, etc. was connected to the bus
To circuit, into digital amount of current data and voltage data to derive the current and voltage of the circuit, and the arithmetic processing for a given program, busbar protective relay device which protects the bus in accordance with the processing result A total bus instantaneous value relay corresponding to the plurality of buses as an operation amount, and a collective bus protection relay for performing a ratio differential operation with the instantaneous absolute value sum or the maximum instantaneous value absolute value of the current data as a suppression amount. The divided bus protection relay of each bus unit for performing ratio differential operation using the instantaneous sum of current data of each bus unit as an operation amount and the maximum sum of instantaneous absolute value or instantaneous value absolute value of the current data as a suppression amount. The bus voltage data instantaneous value of each bus unit is used as a reference amount, the direction discrimination operation is performed using the instantaneous sum of current data values of each bus unit as a comparison amount, and the comparison amount operates according to the outflow direction from each bus. A short circuit direction relay for each line, a means for outputting a logical product output of the output of the collective bus protection relay and the output of the divided bus protection relay for each bus as a trip command output for each bus, and when the bus division disconnector is closed, A trip command circuit having means for blocking a trip command output corresponding to both buses in response to operation of one of the directional relays corresponding to both buses sandwiching the bus segment disconnector. Characteristic bus protection relay. 5. The short-circuit direction relay according to claim 4, wherein the short-circuit direction relay is a ground-fault direction relay, and the ground-fault direction relay derives a zero-phase voltage data instantaneous value of each bus unit and sets it as a reference value. A bus protection relay, wherein a ground fault directional relay is used to derive an effective component of the instantaneous sum of phase current data and use it as a comparison value. 6. A plurality of buses having bus segment disconnectors,
The line leading to the generator, load, etc. was connected to the bus
To circuit, into digital amount of current data to derive the current in the circuit, and the arithmetic processing for a given program, in the busbar protective relay device which protects the bus in accordance with the processing result, the A collective bus protection relay that performs a ratio differential operation using the instantaneous sum of current data corresponding to a plurality of buses as an operation amount and the maximum sum of the instantaneous absolute values of the current data or the maximum value of the instantaneous absolute values as a suppression amount, each of the bus units The sum of the instantaneous value of the current data of the current data as the operation amount, the divided bus protection relay of each bus unit for performing ratio differential operation as the suppression amount with the sum of the instantaneous value absolute value or the maximum value of the instantaneous value absolute value of the current data, The collective differential amount derived by vector synthesis of the corresponding current data is used as a reference amount, the direction discrimination operation is performed using the instantaneous value sum of current data of each bus unit as a comparison amount, and this comparison amount is calculated from each bus in the outflow direction. Means for outputting the AND output of the short-circuit direction relay for each bus unit, the output of the collective bus protection relay and the output of the divided bus protection relay for each bus unit as a trip command output for each bus unit, and the bus segment disconnection Means for preventing trip command output corresponding to both buses in response to operation of one of the directional relays corresponding to both buses sandwiching the bus segment disconnector when the device is closed. A bus protection relay device comprising: 7. The ground fault relay according to claim 6, wherein the short-circuit direction relay is a ground fault direction relay, and the ground fault relay is such that a reference quantity is a collective zero-phase differential quantity, and a comparison quantity is each line zero phase of each bus unit in claim 5. A bus protection relay comprising a relay for summing instantaneous current data. 8. The method according to claim 4, wherein
The collective bus protection relay is a collective differential voltage amount derived by synthesizing current data corresponding to a plurality of buses in parallel, and is a voltage differential collective bus protection relay for detecting the collective differential voltage level. A short-circuit direction relay or a ground fault direction relay is a relay that uses an instantaneous value of the collective differential voltage amount as a reference value. 9. The relay according to claim 4 or 5, wherein the short-circuit direction relay or the ground fault direction relay is obtained from the reference amount (V) and the comparison amount (I _D ) by: | V | · | Z _S · _ID ∠φ | > 0 (however, Z _S and φ are constants, and I _D ∠φ is a phase shift of I _D by ∠φ)
A bus protection relay device characterized in that it is a directional distance relay that operates according to the determination of the bus protection. 10. The relay according to claim 4, wherein the short-circuit or ground-fault directional relay or the directional distance relay changes the sum of the instantaneous value of the current data in each bus unit before and after the occurrence of the accident. A bus protection relay, wherein the relay is a relay whose corresponding amount is a comparison amount.