JP2875188B2 - Differential 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 bus of a substation and the like.
The present invention relates to a digital operation type differential relay device used for a computer. [0002] 2. Description of the Related Art Differential relays use an
Current caused by saturation of the current transformer core due to DC current
Vessel error is a problem. Especially in the case of bus protection,
Fault currents flowing from many terminals are collected at one terminal.
It often leaks out. In such a case, the outflow end
The current of the transformer becomes large and the current transformer is likely to be saturated.
No. The current at the other incoming terminals is relatively small
The current transformer is unlikely to saturate and does not saturate at all
There are many. In this case, the differential current (the sum of the current transformer secondary currents,
The direction of the current shall be positive when flowing into the bus).
Despite the accident, there is a large value and malfunction may occur.
You. As a countermeasure against this, a countermeasure against the saturation of the current transformer is taken.
There is a differential relay that has taken measures. That is, Japanese Patent Publication No. 57-5
No. 0130 is the sum of the absolute values of the terminal currents (scalar
Sum) multiplied by a constant less than or equal to 1 to calculate the differential current
Notable when the value obtained by subtracting the absolute value of (vector sum) is positive
A large amount of suppression is generated. About this drawing
This will be described with reference to FIG. FIG. 2A shows a current transformer when the current transformer is saturated.
Primary current I_pAnd secondary current I_sFigure showing an example of the measured waveform of
It is. As shown in the figure, every one cycle of the AC
Secondary current I in sum_sAnd a period during which there is almost no error
And the secondary current I_sPeriod that causes significant error
Is done. [0005] Secondary of terminal from which fault current flows out due to external accident
The current is the waveform I shown._sAnd the terminal into which the fault current flows
Are not saturated, the differential current I
_d2 (b) is as shown in FIG. Also, the terminal current
Fig. I_rbecome that way. As shown in the figure, the secondary current I_sPeriod without error
The differential current I_dIs almost zero,
Sum of paired values I_rOf Japanese Patent Publication No. 57-50130
Generates and stores a large amount of suppression during this period.
And the differential current I_dMalfunctions even if
It is to prevent it. However, an internal accident occurs during an external accident.
There is a disadvantage that the operation is significantly delayed. Figure 3 shows this case
FIG. 3 is a diagram showing an example of the waveform_iIs the current flowing into the bus
The current I_oIs the terminal from which the fault current flows during an external fault
Current, I_dIs the differential current and the current at the fault point at the internal fault point
be equivalent to. I_rIs the sum of the absolute values of the terminal currents. Time t
₁An internal accident occurred before, and before that was an external accident. If an internal accident occurs in the phase shown in the figure, the accident point
Current (= differential current I_d) Is a DC with a large DC component as shown in the figure.
Offset waveform. When an external accident is within close range
Then, the current change after the occurrence of the internal accident (Theveni
n), most of the flow is between the external accident point and
I do. Therefore, the inflow current sum I_iNo change, outflow end
Current I_oIs the amount of change before the occurrence of the internal accident
The waveform is cancelled, and only the DC component is left, resulting in the waveform shown. Due to such a current waveform, the terminal current is interrupted.
Sum of paired values I_rHas the waveforms shown. Differential power due to DC component
Style I_dIs the sum of absolute values I during the period when_rIs big, during this time
Since the large amount of suppression is stored in the
Can not work with As described above, Japanese Patent Publication No. 57-50130
Thing does not malfunction even if current transformer has significant saturation
Although an internal accident occurs during an external accident as described above,
If this occurs, the operation will be significantly delayed depending on the fault current waveform.
It has the disadvantage that For busbar protection, external
The occurrence of an internal accident during an accident is interrupted, for example, when an external accident is shut down.
This happens when the breaker fails to shut down and breaks,
It is not uncommon. [0011] In view of the above situation, Japanese Patent Application No. 61-12 / 1986
No. 0909 (hereinafter referred to as prior application). This earlier application
Is the differential current I_dAt predetermined time intervals, and
Differential current obtained by converting to digital data
Data (or equivalent data) D_dSample time
Difference using a mutual difference between a plurality of predetermined numbers of data
The value of the function f (d) is calculated and this value is more than the suppression value f (r).
The operation of the differential relay means will be blocked on condition that the
It is something that has been done. This is the implementation described in the earlier application
The example sufficiently solves the aforementioned problem. [0012] However, the embodiment of the prior application
Is the differential current sampled over a given period by the suppression value f (r).
The maximum value of the absolute value of the data, or sampled at the same time
The sum of the absolute values of the terminal current data
The maximum value among the pulled ones, etc., and the predetermined period is 1
It is a cycle or more. For this reason, the suppression value f of the magnitude of the difference function f (d)
For (r), the current transformer was saturated due to an external accident
Small enough during the non-saturation period, but not
Differential current I_d7.7% for the sample near the peak value of
The value is not so big as you can see the example
No. For this reason, the magnitude of the difference function f (d) is
j is determined to be sufficiently smaller than f (r) and the operation of the differential relay is blocked.
To avoid stopping, pay close attention to the design and production
Needed. The present invention has been made in view of the above points.
Yes, the suppression value f (r) of the embodiment of the prior application (in the present invention, the suppression
Provide a means of improving the number f (r)
The magnitude of the difference function f (d) at the time of the accident is smaller than the suppression value f (r).
Not be too small to get more stable operation
It is something that can be done. [0015] SUMMARY OF THE INVENTION The present invention provides differential protection.
Protected section Electricity proportional to the current obtained from each terminal
Is a predetermined sample interval θ_dSample on digital day
Data and process the digital data
Hard-wired normal digital operation type relay that generates operation output
Use it as a mechanism and perform the processing described below.
Thus, the above-mentioned problem is solved. The processing will be described with reference to the drawings. Figure
FIG. 1 is a diagram showing a basic configuration of the processing of the present invention. That is,
In the difference function calculation means of the first method, a plurality of points at different sampling times
A constant number p of differential current data (differential current I_dMore obtained
Data or data D obtained from each terminal current of protection section_j
(Sum of j = 1 to n and n is the number of terminal currents) D_dUsing
To calculate the value of the difference function f (d). Also, when the suppression data calculation means in processing 2 is the same,
Terminal current data D sampled every hour_jSuppress using
Data D_rIs calculated by the suppression function calculating means of process 3.
A plurality of predetermined number p of suppression data D having different pull times_rTo
To calculate the value of the suppression function f (r). Next, the difference function f (d)
Is compared with the value of the suppression function f (r), and the difference function f (d) is
The magnitude is smaller than a predetermined relation than the magnitude of the suppression function f (r).
When the comparison means outputs a blocking output (blocking signal S_TwoOr block
Function f (s)). The differential relay means of processing 5 is
The operation is inhibited by the inhibition output of the comparison means of the logic 4.
Controlled so that it can operate when there is no blocking output. An outline of each of the above processes will be described below. place
The difference function calculating means of the first embodiment calculates the predetermined sample interval θ_s(General
Has θ_d, But θ_s≠ θ_d)
A predetermined number p of differential current data D having different sample times_d
Is used to calculate the value of the difference function f (d) using the difference between
is there. The difference function f (d) is expressed by the p differential currents.
Data D_dIs a function that represents the situation of change in
Yes, when the change is small, that is, the difference between
When the value of the difference function f (d) is small,
Yes, as long as various functions can be used.
Wear. An example of the difference function f (d) is shown below. [0021] (Equation 1)   f (d) = D_dm, D_{d (m-1)}, ... D_{d (m-p + 1)}The absolute value of the difference between the maximum and minimum values of                                                         …………… (1)   f (d) = | S_dm| + | S_{d (m-1)}| + ... + | S_{d (m-p + 2)}｜ ……… (2)     Where S_dm= D_dm-D_{d (m-1)}           S_{d (m-1)}= D_{d (m-1)}-D_{d (m-2)}           S_{d (m-p + 2)}= D_{d (m-p + 2)}-D_{d (m-p + 1)}                                                         …………… (3) And D_dm, D_{d (m-1)}, D_{d (m-p + 2)}And D_{d (m-p + 1)}Is
The latest, one before the latest, (p-2) times before and after the latest, respectively.
Differential current data D at the time of sampling (p-1) times before new_dof
Value.   f (d) = | S_dm|, | S_{d (m-1)}|, ... | S_{d (m-p + 2)}Maximum value of |… (4) The above equation (1) is equivalent to a predetermined number p of differential current data.
TA D_d(The most positive direction) and the minimum (the most
Is also in the negative direction) and the difference function f (d)
Equations (2) and (4) are the sample times, respectively.
Differential current data D_dEach of the absolute values of the differences
The sum or the minimum value is defined as a difference function f (d). these
Any one of the above formulas can be used.
Flow data D_dWhen the change of the value is small, the size is small
Other expressions can be used within a certain range. The suppression data calculation means of the process 2 is executed at the same time.
Sampled terminal current data D_jSuppression day using
TA D_rThe example is shown below. (Equation 2) The above is one suppression data D_rAlso calculate
Equation (5) shows that each terminal current data D_j(However, D_j
Is the terminal current data D₁, D_Two… D_jEach of the)
Equation (6) is the sum of the absolute values, and_jExcellence
This is the maximum value of the pair value. Suppression data D_rInto two as shown in the following example
Suppression data D_r1And D_r2It can be. (Equation 3)However, (D_j)_pIs the terminal current data D_j
Only the negative one of the values is corrected to zero,
(D_j)_nIs the terminal current of only positive ones with their values corrected to zero
Data D_jIs the value of In the above equation (7), D_r1Is the current data of each terminal.
TA D_jIs the sum of the positive_r2Is the terminal current data
D_jIs the sum of the negative ones. In equation (8), D_r1Is zero
And each terminal current data D_jIs the maximum of each value of
_r2Is zero and each terminal current data D_jOf each value of
Is also in the negative direction). The suppression data of the above equations (5), (6), (7) and (8)
The data can achieve its purpose using any of them.
Also, if the value of the current passing through the protection section is large due to an external accident,
It has a character that grows and smells as long as it
It is also possible to use other expressions. The suppression function calculating means in the process 3 is a processing for a predetermined sample.
Interval θ_sQ of suppression data with different sample times
TA D_rCalculate the value of the suppression function f (r) using the difference between
And q pieces of suppression data D_rChange situation
Which is represented by one function,_rof
When the change is small, that is, when the change in terminal current is small
It has the property that the value of the suppression function f (r) becomes smaller.
You. First, an example of the suppression function f (r) is shown as suppression data D_rIs one
The case, that is, the case of equation (5) or (6) will be described. [0030] (Equation 4)   f (r) = D_rm, D_{r (m-1)}, ... D_{r (m-q + 1)}The absolute value of the difference between the maximum and minimum values of                                                         …………… (9)   f (r) = | S_rm| + | S_{r (m-1)}| + ... | S_{r (m-q + 2)}｜ …………… (10)   f (r) = | S_rm| + | S_{r (m-1)}|, ... | S_{r (m-q + 2)}| Maximum value …… (11)     Where S_rm= D_rm-D_{r (m-1)}           S_{r (m-1)}= D_{r (m-1)}-D_{r (m-2)}           S_{r (m-q + 2)}= D_{r (m-q + 2)}-D_{r (m-q + 1)}                                                     ……………… (12) And D_rm, D_{r (m-1)}… D_{r (m-q + 1)}Are the latest and latest respectively
Suppression at one sample before and (q-1) times before the latest
Data D_rIs the value of Equation (9) above indicates that a predetermined number of suppression data D_r
Let the absolute value of the difference between the maximum and minimum values of be the suppression function f (r)
Equations (10) and (11) are adjacent to the sample time.
Suppression data D_rThe sum or maximum of the absolute values of the differences
It is assumed that the function is f (r). These (9), (10) and
Equation (11) is the suppression data D of equation (5) or (6)._rAgainst
The purpose can be achieved by using the deviation. Next, the suppression data D_rIs more than one, ie
Examples of the suppression function f (r) in the case of the equations (7) and (8) are shown. (Equation 4)       f (r) = f (r1) + f (r2) + ... (13)       f (r) = maximum value of f (r1), f (r2) + ... (14) Where f (r1), f (r2) +...
The first, second,... Suppression data D at different times_r1, D_r2... yo
Are the auxiliary functions of the first, second,.
The auxiliary function f (r1) is shown below. [0034] (Equation 6)   f (r1) = D_r1m, D_{r1 (m-1)}, ... D_{r1 (m-q + 1)}And the maximum value of                                         Absolute value of difference between minimum values …… (15)   f (r1) = | S_r1m| + | S_{r1 (m-1)}| + ... + | S_{r (m-q + 2)}｜ …… (16)   f (r1) = | S_r1m|, | S_{r2 (m-1)}|, ... + | S_{r (m-q + 2)}| Maximum value                                                           ............ (17)     Where S_r1m= D_r1m-D_{r1 (m-1)}           S_{r1 (m-1)}= D_{r1 (m-1)}-D_{r1 (m-2)}           S_{r1 (m-q + 2)}= D_{r1 (m-q + 2)}-D_{r1 (m-q + 1)}                                                           ............ (18) And D_r1m, D_{r1 (m-1)}… D_{r1 (m-q + 1)}Is the most
New, one before the latest and (q-1) previous samples
Time suppression data D_r1Is the value of Second and subsequent auxiliary functions f
(r2) are the second or lower suppression data D_r2Using…, (1
Perform the same operation as in equation (5), (16) or (17). The comparing means of the process 4 is to compare the value of the difference function f (d)
Compares the value of the control function f (r) with the value of the difference function f (d)
If the value of the suppression function f (r) is smaller than the sum of the constants,
Generally, when the following equation holds, the blocking signal S_TwoTo produce
I do. [0036] (Equation 7)         f (d) <K₁f (r) + K_Two                .................. (19)         f (d) <K₁f (r) and K_TwoThe maximum value of ............ (20)         f (s) = K₁f (r) -f (d) .................. (21) Where K₁And K_TwoIs a positive constant and K₁The value of
About 0.1-0.5, K_TwoIs the sensitivity of the differential relay
(Minimum operation value). Also, depending on the blocking method,
In some cases, the value of the following rejection function f (s) is output. Note that this blocking output takes about one cycle.
Held for a while. Equations (19) to (21) are equivalent to the difference function f described above.
(d) and the suppression function f (r) are all calculated as
This is a case where the value is calculated using a positive value. If each
If the value of the function is the difference itself and contains negative values,
Expressions (19) to (21) are calculated using the magnitude of each function, that is, the absolute value.
Apply. The differential relay means of the processing 5 is generally a conventional relay means.
Use the same one as the differential relay means of the differential relay. Obedience
The conventional differential relay means is differential current data D_dThe movement obtained
The production amount f (o) is a constant value, or each terminal current data D_iBetter
Greater than the suppression amount f (b) of the value proportional to the given value
It works when it gets old. This means is described, for example, in JP-A-59-20442.
No. 1, etc., and a detailed description will be omitted. This
The operation of the differential relay means such as
There are various means for controlling so as to prevent
Shown in (I) The operation output of the differential relay means is prevented from being generated.
Stop signal S_TwoProhibited by (II) The value of the operation amount f (o) is determined by the inhibition signal S._TwoBy zero or
The value is set to a small value that disables operation. (III) The value of the suppression amount f (b) is determined by the inhibition signal S._TwoMalfunction
It is set to a large value that will be effective. (IV) When the value of the blocking function f (r) is positive, the suppression amount f (b)
, The suppression by the blocking function f (r) is added. In the case of the present invention, the differential relay means is a conventional type.
Differential current data D_dRather than using
After the formula (19) or (20) is not satisfied, a predetermined period (for example,
1 cycle) to detect and operate
It is possible to achieve
What you get. In the above, the predetermined sample interval of the difference function calculation means
θ_sAnd the predetermined sample interval θ of the suppression function calculating means_sIs
It is preferable to make them equal, but do not hinder the effect.
It is also possible to make them different in a different range. In addition, these places
Constant sample interval θ_sIs the predetermined sample interval θ of the original data_d
Need not necessarily be equal to, for example, θ_s= 2
θ_d, Θ_s= 3θ_dUse the original data as
It is possible to use Further, a predetermined number p in the difference function calculating means
And the predetermined number q in the suppression function calculating means is the same number
Is preferable, but within the range that does not affect the function and effect
Can be different. [0044] The operation of the present invention will first be described with reference to the drawings for an external accident.
Will be described. If the current transformer does not saturate due to an external accident,
Differential current I_dIs a very small value and the differential current data
D_dLittle change. Therefore, the value of the difference function f (d) is
Using any of the above equations (1), (2) and (4), almost zero
A certain state is maintained. During this time, the fault current passing through each terminal causes
Therefore, the value of the suppression function f (r) is determined by any of the above-mentioned equations (9) to (17).
It is a large value even if one is used. Therefore, the comparison hand
Eq. (19) or (20) is satisfied in step 4, or Eq. (21) is blocked
When the function f (s) becomes a large positive value, the operation of the differential relay
The work is stopped. Next, when the current transformer is saturated due to an external accident,
Will be described. In this case, one cycle
Once, the value of the difference function f (d) is greater than the value of the suppression function f (r).
It becomes a remarkably small value.
Force is obtained, and this blocking output is held for about 1 cycle or more.
Therefore, the operation of the differential relay means 5 is prevented. This one
Once a cycle, the value of the difference function f (d) is
The phenomenon that the value is significantly smaller than the value is explained below.
You. FIG. 4 shows a terminal in which the fault current is one at the time of an external fault.
And the current transformer at that terminal is severely saturated by the DC component
Current when the current transformer at the incoming terminal is not saturated
FIG. 4 is a diagram showing an example of a waveform and a response of the device of the present invention. In the figure
I_i, I_oAnd I_dIs the secondary current of the current transformer at each inflow terminal
Of the secondary current and differential current of the current transformer at the outflow terminal
is there. Current I_oReverses the positive and negative polarities for convenience of comparison-
I_oIndicated by This current -I_oIs originally the current I_iAnd so on
However, the waveform shown in the figure is due to saturation.
You. Due to this saturation, the differential current I_dWaveform is shown
However, in the non-saturation period of the current transformer that appears once per cycle
A certain time t₁, T_Two, T_ThreeAnd t_FourThen the differential current I_dof
Changes are slight. The difference function f (d) in the illustrated current waveform and the suppression function
An example of the number f (r) is shown by a solid line and a broken line, respectively. This example
Predetermined sample interval θ_sTo the power system frequency sine waveform 3
0 ° and the predetermined number of samples p and q are 3
Unless otherwise described, this value is used), and the difference function f (d) is
Equation (1), suppression data D_rAnd the suppression function f (r) are (5)
This shows the case of the expression and the expression (9). The value of the difference function f (d) is, as shown in FIG.
Before starting, it is almost zero.₁Current transformer
Until the end of the non-saturation period. The value of the difference function f (d) is
Time t_Two, T_ThreeAnd t_FourMarkedly late in the non-saturation period of
It will be a small value. During these unsaturated periods, as shown
Current I_iAnd -I_oLarge change in the non-saturation period
In the latter period, the value of the suppression function f (r) is different from the value of the difference function f (d).
Significantly larger value. Therefore, the equations (19) to (21)
Number K₁Is about 0.1, the blocking output (signal S_Twoor
Can reliably obtain the blocking function f (s)). As described above, the time t before the occurrence of the accident
₁Until the end of the period and once every cycle thereafter
t_Two, T_ThreeAnd t_FourOut of the current transformer every non-saturation period
Power is gained. The figure shows the constant K₁With 0.2 as the constant K_TwoTo
Blocking signal S at extremely small value_TwoOutbreak situation
Show. In this case, the blocking output is continued during each saturation period.
Therefore, there is no malfunction. Next, the difference function f (d) and the suppression function f (r) are given by
Aspect of each value and constant K when changed from the above₁And K
_TwoIs the same as the signal S_TwoThe occurrence situation of
Time t in FIG._TwoNearby period (the non-saturation period of the current transformer is short
FIG.
As shown in FIG. Each figure shows the difference function f (d) and the suppression data D_ras well as
This is the case where the suppression function f (r) is as follows. What
In the following, only f (r1) is shown for auxiliary functions
However, other auxiliary functions below f (r2) also have the same arithmetic expression as f (r1).
And [0054] [Table 1]         Difference function f (d) suppression data D_r  Suppression function f (r) Auxiliary function f (r1)   Fig. 5 Equation (2) Equation (5) Equation (10) −   Figure 6 Equation (4) Equation (5) Equation (11) −   Fig. 7 (1) Equation (7) Equation (13) Equation (15)   Fig. 8 Equation (1) Equation (7) Equation (14) Equation (15) In any case, at time t_TwoLate
The value of the number f (d) becomes significantly smaller, at which time the suppression function
The value of f (r) is significantly larger than the value of the difference function f (d).
The blocking output is obtained, which is
It is repeated during the sum period. FIGS. 5 and 6 show suppression data D in each figure.
_r, The difference function f (d) and the suppression function
Change f (r) to Eq. (2) or (4) and Eq. (10) or (11), respectively.
7 and 8 show the difference function f (d) as in FIG.
Data D_rAnd the suppression function f (r)
Things. The difference function f (d) of FIGS.
Or, add auxiliary function f (r1) and others to Eq. (16) or Eq.
Even if it changes, illustration is omitted, but the blocking output
Can be That is, when the predetermined numbers p and q are 3, the expression (2)
And the value of equation (16) is 1-2 times the value of equations (1) and (15), respectively.
(4) and (17) are the values of (1) and (1), respectively.
5) It is in the range of 1/2 to 1 time of the value of the equation, and the value of each figure is
Range and constant K₁To about 0.1
A blocking output is obtained. The above is the suppression data D_rLet Eqs. (6) and (8) be
The waveform example of the suppression function f (r) in the case of
However, this will be described. In the case of general application, external matters
Therefore, the number of terminals from which the fault current flows is about 1 to 2 terminals.
You. The current transformer at the outflow terminal was saturated to the same extent.
Then, the example of the sum of the secondary current waveform of the current transformer at the outflow terminal
Is the current -I of FIG._oThe same as the one with the sign changed
If the current flows out of the two terminals,
The maximum value of the pair value is the current -I in the figure._oLess than 1/2 of the absolute value of
It won't be cheap. Here, the non-saturation period of the current transformer, for example, the time t
_TwoFocusing on the equation, each terminal current data D_jAbsolute
The maximum value is the terminal current data D in equation (5)._jOf the absolute value of
It will not be less than 1/4 of the sum. Therefore,
Control data D_r(6), the latter part of the non-saturation period
The value of the control function f (r) is the suppression data D_rIs the expression (5)
It will not be smaller than 1/4 of the combined value. The suppression function f in the latter half of the non-saturation period shown in FIGS.
The value of (r) is sufficiently large with respect to the value of the difference function f (d).
And the constant K₁Is about 0.1, the suppression function f shown
Even if the value of (r) is reduced to 1/4, a blocking output can be reliably generated.
And suppression data D_r(6)
It can produce output. The suppression data D_r1And D_r2Is given by equation (8).
The value of the suppression function f (r) in the latter half of the non-saturation period
Data D_r1And D_r2Is less than 1/4 when Eq. (7) is used
It does not decrease, and the blocking output can be reliably generated.
Wear. As described above, the suppression data described in the equations (5) to (17) is used.
Data D_rAnd the suppression function f (r),
In the event of an external accident involving saturation of the
It is. Next, the response in the event of an internal accident will be described. FIG. 9-
FIG. 12 shows various differential currents I during an internal fault._dFor the waveform of
The aspect of the values of the difference function f (d) and the suppression function f (r) is shown. Each figure
Is the differential current I_dWaveform, difference function f (d), suppression data
D_r, The suppression function f (r) and the auxiliary function f (r1) as follows:
This is the case. [0065] [Table 2]           I_dDifference function of suppression data suppression function auxiliary function           ^{Waveform f (d) Dr f (r) f (r1)}     Figure 9 Figure (1) Equation (5) Equation (9) Equation −     Figure 10 Equation (1) Equation (5) Equation (9) −     Fig. 11 Figure (1) Equation (5) Equation (9) −     Figure 12 Figure 11 Equation (1) Equation (7) Equation (13) Equation (15) The differential current I shown in FIG._dThe waveform of
This is an example where all current transformers are not saturated.
The attenuated DC component is superimposed on the AC current.
You. Since the currents at the inflow terminals are almost in phase,
Dynamic current I_dThe waveform is almost the same as the above, and the amplitude is smaller than Id
It has become a bad thing. The differential current I shown in FIG._dWaveform shows that the fault current is
Inflow from only one terminal, the current transformer at that terminal becomes significantly saturated
This is an example of a case where Example of fault current inflow from other terminals
There is no. FIG. 11 shows the waveform of the terminal into which the fault current flows.
The current transformers of some terminals are saturated and the current transformers of other terminals
This is an example in a case where the saturation does not occur. Current I shown_iIs the unsaturated end
The current of each non-saturated terminal has a waveform I_i
And the amplitude is I_iLess than. Also, the current I_i′
The sum of the currents at each saturated terminal.
Is I_i'And the amplitude is I_iLess than. Differential power
Style I_dIs the current I_iAnd I_i′, The waveform shown
You. The difference function f (d) and the suppression function f shown in FIGS.
(r) expresses the difference function f (d) as
Control data D_rIs given by equation (5), and the suppression function f (r) is given by equation (9).
The value of the suppression function f (r) is the value of the difference function f (d)
Does not increase with respect to, and the constant of the equation (19) or (20)
K₁Is set to, for example, about 0.2 to 0.5 or less.
No blocking output is produced. The above relation is obtained only for the differential current.
Data D_dIs small, the suppression data D_r
Is also small. 9 and 10 waves
In the form, the differential current I_dAnd the terminal current I_jWaveform
Similarly, the differential current I_dWhen the change is small at each end
Child current I_jChanges are small. Therefore, the suppression data D_rAnd the suppression function f
In (r), each of the equations described in [Means for solving the problem]
Even if the deviation is used, it is suppressed when the value of the difference function f (d) is small.
The value of the control function f (r) also becomes small, and the blocking output appears.
Absent. On the other hand, the time t of the waveform of FIG.₁Near
Then, the current I_iCurrent I_i′ Decreases
And the differential current I_dChange becomes smaller
The suppression data D_rAnd the selection of the suppression function f (r)
In some cases, when the value of the difference function f (d) is small, the suppression function
The value of the number f (r) may increase. Therefore, the figure
Reference numeral 12 describes the response to the waveform of FIG. FIG. 12 shows the suppression data D in FIG._rAnd oppression
The control function f (r) is modified as described above. this
In this case, the value of the suppression function f (r) is
Always equal, thus blocking as in FIGS. 9-11
No output is produced. Next, the difference function f (d), not shown,
Data D_rAnd the case of the suppression function f (r)
I will tell. 9 to 12 when the predetermined number p is 3,
The difference function f (d) is expressed by equation (2), and the suppression function f (r) is expressed by equation (10).
Even if the function f (r1) is changed to the equation (16), the value of each function is
And the difference function f (d) is (4)
Equation, the suppression function f (r) is expressed by equation (11), and the auxiliary function f (r1) is expressed by equation (17).
The value of each function is in the range of 1１ ／
In the box. Therefore the constant K₁Less than 0.5
As far as possible, no blocking output is reliably produced. The blocking data D_rTo (6) instead of (5)
When the expression is used, and when the expression (8) is used instead of the expression (7),
And the rejection function f (r) is given by equation (14) instead of equation (13)
In any case, the value of the blocking function f (r) is
Smaller, and there is no risk of blocking output. Finally, there was a transition from an external accident to an internal accident.
The case of FIG. 3 will be described. In the case of the figure, the differential current I_dIs the current
I_iAnd I_oAnd the current I_oChanges were slight
The current I_dChanges in the current I_iIs almost the same as
You. Therefore, the response after the shift to an internal accident is
This is the same as a local accident, and no blocking output occurs. As described above, the means of the present invention is applied to the current transformer.
Even in the event of severe saturation, the blocking output is ensured in the event of an external accident
That does not produce blocking output in internal accidents.
Yes, which can reliably identify and protect against internal accidents
Is to do so. [0078] Embodiment [First Embodiment] FIG. 13 is a block diagram showing the hardware configuration of the first embodiment of the present invention.
FIG. In the figure, B is a protected bus, CB₁, CB
_Two, CB_ThreeAnd CB_nIs the cutoff provided at each terminal of the bus
Vessel, CT₁, CT_Two, CT_ThreeAnd CT_nIs each terminal of the bus
Current I_p1~ I_pnCurrent transformer for inputting the CV₁, CV
_Two, CV_ThreeAnd CV_nIs an input converter and DAU is a data
The acquisition device and CPU are a processing device, and OU is an output device. Each current transformer CT₁~ CT_nSecondary current is input
Converter CV₁~ CV_nAnd the secondary current I_s1~ I_sn
Electric quantity E proportional to₁~ E_nIs generated. Data acquisition device D
AU is electric quantity E₁~ E_nAt the same time and at predetermined time intervals.
And convert the value to digital data,
Data D_j(J = 1 to n). The processing unit CPU receives the terminal current data D
_j, And if the operation condition is satisfied, the operation signal S₁
Is generated. The output device OU outputs the operation signal S₁Works when there is
Output E_oIs generated. FIG. 14 is a diagram showing the configuration of the processing of this embodiment.
You. First, in process 6, data D_jIncorporate the latest sample
Data D_jmTo be stored. Then, in process 7, the data D_jm
And differential current data D as basic data_dAnd oppression
Control data D_rD at the time of the latest sample_dmAnd D_rm
Is calculated by the following equation and stored. [0082] (Equation 8)       D_dm= D_1m+ D_2m+ D_3m+ ... + D_nm       D_rm= | D_1m| + | D_2m| + | D_3m| + ... + | D_nm|                                                       …………(twenty two) Where D_1m, D_2m, D_3mAnd D_nmIs the data D_jmEach end of
This is data for each child. After creating these basic data, the process 8
And the difference function f (d) and the suppression function f (r) are given by
Calculate according to equation (9). After this processing, the comparison step of processing 9
Perform the processing of the step, and further perform the processing of the differential relay means of processing 10.
Do. After these processes, rewrite the data in process 11.
And returns to processing 6. Example of rewrite process in process 11
Is the sample interval θ_dAnd θ_sWhen both are set to 30 °
(Shown below unless otherwise specified)_d= Θ
_s= 30 °. ). [0084] (Equation 9) However, in each expression, X indicates that data is discarded.
Where d and r are positive integer constants. Constant d and
The value of r differs depending on the contents of processing 9 and 10, but
In the case of the embodiment, d = 6 and r = 12, each for a half cycle
And data for one cycle. FIG. 15 shows the details of the process 9. First processing 9-1
Perform any comparison of formulas (19) and (20) with (19) or
If equation (20) holds, the result of step 9-1 is set to Y and
If not, set N. If the processing result of processing 9-1 is Y
Signal S in processing 9-2_TwoIs 1 and if N, the signal S_TwoTo
The value is set to 0, and the process 9 ends. FIG. 16 shows the details of the process 10. First, processing 10-1
At signal S_TwoCheck the state of_TwoIs 0, the process 10-2
Add 1 to the count value C, and add this value to the new count value.
C. S_TwoIf the value is 1, the count value C is obtained in step 10-3.
Correct to 0. After these processes, count in process 10-4
Check the value C, and if the value is 12, count in process 10-5
Post-processing to subtract 1 from value C to obtain new count value C
Move to 10-6. Next, in step 10-6, the operation amount f (o) is
-7 is used to calculate the suppression amount f (b). Further, in processing 10-8, the operation amount f (o) and the suppression amount f
(b) is compared, and if the processing condition is satisfied, the processing result is set as Y.
If not, the processing result is set to N. Processing 10-8
If the result is Y, the signal S is obtained in step 10-9.₁Is set to 1. processing
If the count value C is not 12 in 10-4, and if
If the processing result is N, the signal S₁Is set to 0.
Signal S₁Is 1, the output E is output to the output device OU in FIG._o
And a cutoff is commanded. The processing of steps 10-6 to 10-8 is the same as that of the conventional differential processing.
Known as a relay, an example is shown below. Processing 10-6
The amount of operation f (o) at step and the amount of suppression f (b) at step 10-7 are
For example, it is calculated by the following equation. [0090] (Equation 10) Equation (26) shows the data D during the past half cycle._dof
Equation (27) is the sum of absolute values,
Data D_rIs the maximum value of In the process 10-8, for example,
When the condition (1) is satisfied, the operation condition is set. [Equation 11]         f (o) ≧ K_Threef (b) and K_FourSum of (or maximum value) ……… (28)           Where K_ThreeAnd K_FourIs a positive constant. In this embodiment, the difference function f (d) and the suppression data D_r
And the suppression function f (r) as equations (1), (5) and (9), respectively:
When the equation (19) or (20) is satisfied, the blocking signal S_TwoWill produce
And the blocking signal S_TwoOperation of the differential relay means when
Prohibit and signal S₁Is prevented from occurring. Signal S_TwoIs as described above every cycle
But the signal S_TwoWhen the value becomes 1, the processing 10-3
To set the count value C to 0 and the signal S_TwoEven if the value becomes 0
Event value C only increases by one for each sample.
You. Therefore, the count value C reaches 12 and the process 10-4 proceeds.
It takes one cycle for the ban on differential relay means to be lifted.
The differential relay means may malfunction due to an external accident.
Absent. Also, during normal operation, the differential current data D_dIs zero
And the suppression data D_rIs a small value depending on the load current.
ing. As a result, equation (19) or (20) holds, and the signal
S_TwoIs 1 and the count value C is also 0. this
When an internal accident occurs in the state, the signal S_TwoImmediately becomes 0
The count value C becomes 12 after one cycle, and the differential
The operation prohibition of the electric means is released and the protection operation is performed. [Second Embodiment] In the second embodiment, only the processing 10 of the first embodiment is changed.
FIG. 17 shows the process 10 of the present embodiment. Figure 16 and
The same parts are indicated by the same symbols. Processing 10-11 is the operation amount f (o)
Is a process for setting the value of. First, the processes 10-1 to 10-4 are performed in the same manner as in FIG.
Do the work. Process 10-4 and later when the count value C is 12
Is exactly the same as in FIG. Count value C is
If it has not reached 12, the operation amount f (o) is calculated in step 10-11.
After setting the value to zero, the processing after processing 10-7 is performed in the same manner as in FIG.
U. In this embodiment, when the count value C is less than 12,
By setting the operation amount f (o) to zero,
The signal S is set so that the processing result becomes N.₁With 0
And at this time the signal S₁Becomes 0 in the first implementation
This is the same as in the example. Also, the count value C reaches 12
Is performed in the same manner as in the first embodiment. did
Therefore, the signal S of the present embodiment is₁Is exactly the same as the embodiment of FIG.
It will respond. When the count value C is 12, the operation amount f
Change (o) to a sufficiently small value, not just zero
Or by changing the suppression amount f (b) to a sufficiently large value.
Therefore, the processing result of processing 10-8 is set to N.
Is also possible. This means determines the amount of operation f (o) in process 10-6.
The calculated value or the calculated value of the suppression amount f (b) in the process 10-7 is counted
To provide a means to change when the default value C is 12.
Therefore, detailed description is omitted for simplicity.
You. [Third Embodiment] In the third embodiment, only the processing 10 of the first embodiment is changed.
FIG. 18 shows the processing of this embodiment. Fig. Same as Fig. 16
A part is indicated by the same symbol. First, processing is performed in the same manner as in FIG.
Perform 10-1 to 10-4. Process when count value C is 12
At 10-5, subtract 1 from the count value C to obtain a new count value
C and then the signal S₁Is set to 1. Count value C is 12
If less than the signal S₁Is set to 0. The difference of this embodiment from the first embodiment is
When the count value C is 12, the processing of steps 10-6 to 10-8 is performed.
Signal S directly₁Is set to 1. this
The points will be described. First, in the section of the means for solving the problem,
As you can see, the signal S_TwoIs continuously 0 during an internal accident
Therefore, one cycle after the internal accident occurs,
When the count value C reaches 12, the signal S₁Becomes 1. Also outside
In the event of a head accident, the signal S_TwoIs 1
Once a cycle, it becomes 1 and the count value C reaches 12.
Never. During normal operation, the differential current I_dContinuously
Zero, and each terminal current I_jIs the current from the load
You. This condition is the same as an external accident without current transformer saturation.
The value of the difference function f (d) is zero, and the suppression function f (r) is
It is a small value depending on the load current. It happens that each terminal current I
_jAre all zero and the value of the suppression function f (r) is zero.
In this case, the differential current I_dIs also zero
The value of the difference function f (r) is also zero. In either case (19) or
Equation (20) is continuously established and the signal S_TwoContinuously becomes 1
Therefore, the count value C does not become 12. As described above, the count value C is determined by the internal accident.
The signal S₁Becomes 1. Therefore
This embodiment can be applied similarly to the first embodiment.
You. It should be noted that there is an intermediate point between the present embodiment and the first embodiment.
Equation (28) can be applied with the suppression amount f (b) set to zero.
Noh. This is shown in FIG.
The first embodiment may be applied by setting f (b) to zero.
Therefore, detailed description is omitted for simplicity. [Fourth Embodiment] The fourth embodiment is a modification of the processes 9, 10, and 11 of the first embodiment.
This will be described. Fig. 19 shows this implementation
It is a figure which shows the process 9 of an example. First, in process 9-4,
Then, the value of the blocking function f (s) is calculated, and this value is calculated in processing 9-5.
The value f (s) of the calculated blocking function_mTo be stored. Next processing
This f (s) in 9-6_mIs checked, and if negative, processing 9-7
And f (s)_mTo zero, and if zero or positive, correct
Absent. Thus, the process 9 ends. FIG. 20 shows the process 10 of this embodiment. Figure 16
The same parts are indicated by the same symbols. First, processing 10-6 and 10-7
And the values of the operation amount f (o) and the suppression amount f (b) in the first embodiment.
It is calculated as in the case. Next, in processing 10-12,
The inhibition amount f (t) is calculated. [0106] (Equation 12)   f (t) = f (s)_m, F (s)_(m-1), ... f (s)_(m-11)Maximum value (or sum) of                                                         ………… (29) Where f (s)_(m-1)… F (s)_(m-11)Is the latest sample
With the value of the rejection function f (s) at the time of sampling 1 ... 11 times before
is there. This value is the value of the stop function f (s) during the past one cycle.
(Or the sum of positive ones). Further, the comparison processing of processing 10-13 is performed, and the following equation is obtained.
Is satisfied, the processing result is set to Y, and if not, the processing result is set.
Is N. (Equation 13)       f (o) ≧ K_Threef (b), K_Fivef (t) and K_Four(Or maximum)                                                       ............ (30)         Where K_FiveIs a positive constant. If the processing result of processing 10-13 is Y,
Signal S at 10-9₁Is set to 1 and if N, the signal is
S₁Is set to 0, and the process 10 ends. In process 11, the blocking function
f (s)_m, F (s)_(m-1), ... f (s)_(m-11)For the value of
Rewriting similar to that for other data is added to the first embodiment.
Be added. This embodiment is different from the first to third embodiments in that the blocking signal
S_TwoPrevents the malfunction of the differential relay means
Therefore, an attempt is made to prevent malfunction by the blocking function f (s).
It is. In the case of an external accident, the stop signal S_TwoIs one cycle
The stopping function f (s) is 1
Once every cycle, it is always positive. Therefore, the equation (29)
The stopping amount f (t) is also always a positive value. Therefore, the equation (30)
Number K_FiveIf is set to a sufficiently large value, Equation (30) holds.
Signal S₁Does not become 1. In the case of an internal accident, the signal S_TwoIs continuous
The blocking function f (s) is continuously negative
You. Therefore, the blocking amount f (t) is always zero, and the processing 10-1
The processing of 3 is a constant K_FiveThe processing is the same as that of processing 10-8 regardless of the value of
Looks like Therefore, as in the case of the first embodiment, the signal
S₁Becomes 1. As described above, this embodiment is different from the first embodiment.
It is equally applicable. Note that the constant K_FiveNo value for
In the case of the limit, the signal S_TwoOperation of differential relay means
This has exactly the same effect as stopping. [Fifth Embodiment] In all of the above embodiments, blocking output is generated during continuous operation.
This blocking output is held for one cycle in process 10.
You. For this reason, even if an internal accident occurs, the differential
The power supply is inoperable and does not cause a one-cycle operation delay.
You. The fifth embodiment is for eliminating this operation delay.
It is. The processing of this embodiment is shown in FIG. The figure is
An accident initial process of process 12 is added between process 9 and process 10.
Others are the same as FIG. Processing other than processing 12 is the first
Is the same as that of the embodiment. FIG. 22 shows the details of the process 12. First, processing 13
To detect an accident, and if an accident is detected, the processing result is Y
If not detected, the processing result is set to N. This process
If the result is Y, the count value C 'is checked in step 12-1.
If the count value C 'is 1 or less, the count is performed in step 12-2.
One is added to the value C 'to obtain a new count value C'. Change
In step 12-3, the count value C used in step 10 is set to 11.
Correct and end process 12. In the process 12-1, the count value C 'exceeds 1.
Then, the process 12 ends. Also, the processing result of processing 13
Is N, the count value C 'is corrected to 0 in step 12-4.
Processing 12 ends. In these cases, repair of the count value C
No correction is made. In short, in process 12, accident detection is performed.
If not, the count value C 'is always 0. accident
When the detection is performed, 1 is added to the count value C '.
However, when the count value C 'becomes 2, this addition is not performed.
No. An accident is detected and the count value C '
Corrects the count value C of processing 10 to 11 only when
Correct. That is, the first and next suns where the accident detection was performed
Corrects the count value C to 11 only during the pulling process
I do. The details of the process 13 are shown in FIG. First, processing 13
-1 is compared, and if the following equation is satisfied, the processing result is Y
If not, the processing result is set to N. [Equation 14]         ｜ D_j| Maximum value ≧ K₆            ………………… (31)           Where K₆Is a positive constant. If the processing result of processing 13-1 is Y, processing 13-2
The count value C ″ is set to 12 and the processing result of the processing 13 is set to Y.
And set it in the accident detection state. Processing result of processing 13-1 is N
If it is, the count value C ″ is checked in processing 13-3, and C ″ ≧ 1.
In step 13-4, 1 is subtracted from the count value C "to obtain a new value.
It is assumed that the count value is C ″ and the processing result of the processing 13 is Y.
You. In step 13-3, the count value C ″ is less than 1, that is, 0.
If so, the processing result of the processing 13 is set to N. At this time the count value
C "is not changed. In the above processing, the constant K₆Value of the load current
Is the maximum value of each terminal current data | D_j|
If the value is slightly larger than the maximum value, equation (31) is always running
Does not hold. Normal internal accidents and current transformers
In the case of an external accident that may cause saturation, equation (31)
Once is established, the processing result of the processing 13-1 is set to Y. When the result of the process 13-1 becomes Y, one cycle
Between the vehicles, the count value C ″ is 1 or more, and the
The result is Y. Therefore, normal internal accidents and current transformer saturation
In the case of an external accident that may cause harm, the results of process 13 are continuous.
Then, the state becomes Y and an accident is detected. The overall operation of this embodiment will be described. This implementation
The example processing is the first and next samples where the incident detection was performed.
Time (hereinafter, this sample time is referred to as f1 and f2 samples, respectively)
Only) is different from the first embodiment. these
In the process at the time of sampling, the count value C is 11
Therefore, the signal S_TwoIf the value is 0, the count value C is obtained in step 10-2.
Becomes 12, and the processing of the processing 10-5 and thereafter is performed. The signal S_TwoIf the value is 1, the cow is processed 10-3.
The count value C is returned to 0. Sun after f2 sample
At the time of pull, processing is performed in the same manner as in the first embodiment, and the signal S_TwoIs 0
When it becomes, 1 is sequentially added to the count value C. Immediately
In the process at the time of sampling f1 and f2 in the early stage of accident detection,
Is the prior signal S_TwoSignal S regardless of_TwoIf is 0, immediately
Then, the processing after the processing 10-5 is performed. The signal S at the time of sampling f2 is_TwoIs 1
Then, the subsequent processing is the same as in the first embodiment, and the signal S_TwoBut
1 cycle for count value C to reach 12 even when it reaches 0
During this time, the processing after processing 10-5 is not performed and the signal
S₁Is set to 0. In the case of an external accident, as shown in FIG.
Differential current I_dRise more than the rise of each terminal current.
Be late. During this time, the signal S_TwoIs 1 and at least f1 and
And the signal S_TwoIs 1. this
Therefore, the differential relay means is incorrect in processing at the time of sampling f1 and f2.
It does not operate, and it is not processed in the process after f2 sample.
Does not malfunction as in the first embodiment. In the case of an internal accident, the differential current I_dIs each terminal
It rises at the same time as the current. Therefore, the signal S_TwoIs less
In both cases, it becomes 0 at the time of f2 sample, and the processing of processing 10-5 or less
Is performed, the processing result of processing 10-8 becomes Y, and the signal S₁Is 1
Thus, the protection operation is performed. As described above, in the present embodiment, f
Only at the time of 1 and f2 samples, the signal S_TwoIf 0, cow
By setting the event value C to 11, the signal S_TwoIn the state of 1
Eliminate retention and increase internal accidents without delay of one cycle
It is intended to protect the speed. The above-mentioned accident initial processing of processing 12 is added.
Means to be applied to the other second and third embodiments.
It is also possible to operate
This can speed up the protection of the accidents. It should be noted that the processing 13-1 of this embodiment is performed by suppressing the equation (6).
Data D_rDetected that the value of
However, instead of this, the suppression data D in equation (5)_rOr
Suppression data D of equation (7)_r1And -D_r2Is the constant value
The same applies to detecting the above
Can be detected. [Sixth Embodiment] The sixth embodiment is intended to protect internal accidents at a high speed.
A second means is provided. This embodiment is the first
Only the processing 9 is changed from the embodiment.
Details of No. 9 are shown in FIG. In process 9 in FIG. 24, first, the accident detection in process 13 is performed.
Do. If an accident is detected and the processing result is Y, processing 9-
8 to check the count value C ', and if C' = 1, the process 9-1.
Subsequent processing is performed in the same manner as in the first embodiment (FIG. 15). In process 9-8, count value C 'must be 1
For example, in step 9-9, 1 is added to the count value C 'to
In step 9-3, the signal S is obtained._TwoIs set to 0.
Also, when an accident is not detected in process 13 and the process result is N
Corrects the count value C 'to 0 in step 9-10, and
At signal S_TwoIs set to 0. In process 9 of this embodiment, an accident is detected.
If not, signal S_TwoIs 0, and the cout value C ′ is
It is set to 0. At the time of the f1 sample when the accident was detected
Since the count value C ′ is 0, the count value C ′ is
Also, the signal S_TwoIs left at 0. At the time of f2 sampling, the count value C 'is 1
Therefore, the processes after the process 9-1 are performed.
That is, the processing after the processing 9-1 is performed and the signal S_TwoIs 1
What can be obtained is at the time of f2 sample after the accident detection and after that
At the time of sampling, and no accident detection is performed.
At the time of f1 sample, the signal S_TwoIs set to 0. The operation of this embodiment will be described. Always signal S
_TwoIs 0, but the differential current I_dIs very little
Since the processing result of the processing 10-8 in FIG. 16 becomes N in the processing 10,
Signal S₁Is 0. In the event of an external accident, the differential current I_dIs
At least until f2 sample even if current transformer is saturated
Does not rise, so the result of processing 10-8 is N
The state is maintained. In the case of the f2 sample, the processing of processing 9-1 is performed.
Since the result is Y, the signal S_TwoBecomes 1. Therefore f2
The processing after the sampling is the same as in the first embodiment,
No. S₁Does not become 1. At the time of an internal accident, a series
Subsequently, the processing result of processing 9-1 is N. Before the accident
Signal S_TwoIs 0, the count value of process 10
C is 12 continuously at the stage where the process 10-4 is performed.
During this time, the process 10-8 is continuously performed. Processing 10-8 is
Since the processing result is set to Y immediately after the occurrence of an internal accident, high speed
Operation is possible. As described above, in this embodiment, the accident detection is performed.
At the time of f1 sample immediately after the state where it was not detected and the accident was detected,
Signal S_TwoInternal affairs by prohibiting
Can be protected at high speed without delay of one cycle
It was done. Such means are different from the second embodiment.
It is also applicable to
It is possible to protect internal accidents at high speed
You. In the above fifth embodiment, at the time of sampling f2,
And the signal S_TwoIs 1 when the signal S
_TwoIs kept at 1. Also, the sixth fruit
In the embodiment, from f2 sample and after
Signal S_TwoWas able to be 1. These controls
Which sample to start with at the beginning of accident detection
Is the non-saturation period of the current transformer at the beginning of the external accident
(FIG. 4t₁) That can be variously changed within the range not exceeding
It is. [Seventh Embodiment] The seventh embodiment is intended to protect internal accidents at a high speed.
The third means is provided. The processing of this embodiment
As shown in FIG. The figure shows the data correction process of process 14 after process 7
Is the same as FIG. 14 except that is added. This embodiment is processing
14 is added and process 9 is changed as described below.
Are the same as in the first embodiment. FIG. 26 shows the details of the process 14. First, processing 13
If an accident is detected and the processing result is Y,
The processing 14 is terminated as it is. Process 13 detects an accident
If the processing result is N, the data D
_dmAnd D_rmIs corrected to zero, and the process 14 ends. Processing 9
In the comparison means, the equation (19) is_TwoUse as a negative constant
Other than the above, processing is performed in the same manner as in the first embodiment. Constant K_Twoof
The absolute value is a sufficiently small value, and the suppression function f (r) at the time of the accident is
Make it negligible for the value. In this embodiment, the difference function f (d) and the suppression function
f (r) is calculated using only the data after the accident detection.
Before the accident detection, all data values used are zero.
And the constant K in equation (19)_TwoIs negative, the signal S_TwoIs 0
is there. Therefore, in case of an internal accident, processing 10-13 is immediately performed.
Signal S₁Is set to 1 to protect at high speed. In an external accident
At the same time as the accident detection is performed, the signal S_TwoBecomes 1 and the current changes
Malfunction of the differential relay means due to device saturation is prevented. As described above, in this embodiment, the data after the accident is detected
The difference function f (d) and the suppression function f (r) using only
To provide high speed protection in the event of an internal accident.
Things. Similar means are used for the second and fourth embodiments.
And can protect internal accidents at high speed as well
You can do as much as you can. In the fourth embodiment, the expression (21)
The value of the stop function f (s) is zero before an accident is detected. For this reason,
The rejection amount f (t) in equation (29) is calculated only from the data after detecting the accident.
In the event of an internal accident, it will not be positive from the beginning of the accident.
And can be protected at high speed. [Eighth Embodiment] In the eighth embodiment, the processing 7, the current 13, and the processing of the fifth embodiment are performed.
11 is changed as follows. In processing 7, the equation (22)
Data D_dmAnd D_rmData D_pmAnd D_nmNext
It is calculated by an equation and stored. [0144] (Equation 15)However, (D_jm)_pAnd (D_jn)_pAre each
Terminal current data D_jD at the time of the latest sample_jmof
The value of only negative ones and the value of only positive ones are fixed to zero.
Data D_pmAnd D_nmAre the latest
Each terminal current data D at the time of sample_jmSum of positive and negative
It is. FIG. 27 shows the details of the process 13 in this embodiment. Destination
Data D in process 13-5_dmCheck the value of and if
The processing result is set to Y, and if not satisfied, the processing result is set to N. (Equation 16)           ｜ D_dm| ≧ K₈            ……………… (34)           Where K₈Is a positive constant. If the result of the processing 13-5 is Y, the processing 13
-7, the count value C ″ is set to 12, and the processing result of processing 13 is set to Y.
And If the processing result of the processing 13-5 is N, the processing 13-6
A change is detected, and if the following equation is satisfied, the processing result is set to Y.
If not, the processing result is set to N. [0148] [Equation 17]     D_pmAnd -D_nmThe maximum value of ≧ K₉｛(D_{p (m-1)}, D_{p (m-2)}… D_{p (m-12)}of             Maximum value) and (-D_{n (m-1)}, -D_{n (m-2)}… -D_{n (m-12)}Maximum value of             The maximum value of｝ and K_TenSum or maximum value of ……………… (37)       Where K₉Is a constant of 1 or more, K_TenIs a positive constant. If the processing result of processing 13-6 is Y, processing 13
-8, the count value C ″ is set to 36, and the processing result of the processing 13 is set to Y
And If the processing result of the processing 13-6 is N, the processing 13-3
The count value C "is checked, and if C" is 1 or more, processing 13-4.
Subtracts 1 from the count value C "to obtain a new count value.
C ", and the result of processing 13 is Y. In processing 13-3,
If the count value C ″ is less than 1, that is, 0, the count value
The processing result of processing 13 is set to N without changing C ″.
You. In the processing 11, the following processing is added to the first embodiment.
Is done. (Equation 18) The response of the present embodiment to the fifth embodiment
The difference is only the accident detection process of process 13.
explain. The differential current data D_dmIs constant
Value K₈At this point, the count value C ″ becomes 12, and
Regardless of the result of processing 13-6, processing 13
The processing result becomes Y, and an accident detection state is set. Accordingly
Differential due to an internal accident or an external accident accompanied by current transformer saturation.
Current I_dIs generated once a cycle,
Holds, the differential current I_dUntil it stops flowing periodically
, The accident detection state continues. In the case of an external accident or internal accident, the accident current is
After passing through the protection zone, the value on the left
It becomes larger for similar values, and equation (35) holds. this
As a result, the processing result of the processing 13-6 becomes Y. Equation (35) is the latest
Data D_pmAnd -D_pmIs the maximum value for one cycle before
Compared with similar data of, it became larger than the specified condition
This is true when the accident occurs
You. However, it is established within one cycle after the accident occurs.
Disappears. Therefore, the result of processing 13-6 is immediately after the accident
And becomes N within one cycle. But processing 13-8
The count value C ″ is corrected to 36 in
The result is kept at Y for three cycles. [0154] Since the response is as described above,
Is the result of processing 13 from the occurrence of the accident until the accident is recovered
Becomes Y. In the case of an external accident, take action as soon as the accident occurs13
Results in Y, but soon the result of processing 13-6
Becomes N, so three or more cycles
The differential current I such that equation (34) holds_dIf it does not flow
The processing result of the processing 13 becomes N. Generally severe in external accidents
If current transformer saturation occurs, within 3 cycles after the accident
The differential current I_dFlows, the processing result in such a case
Are continuously Y. However, in this embodiment, the processing result of the processing 13 is Y
It is necessary to be in an accident detection state because of an internal accident.
And when the current transformer causes severe saturation due to external accidents.
Yes, even if the accident detection is performed as in this embodiment,
Absent. In the present embodiment, processing 13-5 is used as another means.
Can be. In the first example, the following equation is used.
It is. [Equation 19]       ｜ D_dm| ≧ K₁₁f (b) and K₈Sum of (or maximum value) ……… (38)         However, f (b) uses equation (27) and K₈Is a positive constant. This is because the slight suppression amount K₁₁f (b)
And the constant K₁₁Unless is increased, it is almost the same as equation (34)
Perform a similar response. In the second example, in the process 13-5, the undervoltage relay process is performed.
It is to do the processing. For this processing, hardware configuration
Is the CV in FIG.₁~ CV_nInput converter CV similar to_vTo
Add this input converter CV_vIs connected to bus B on the primary side
Connect the secondary circuit of the instrument transformer to be used. Input transformer
CV_vOutput electric quantity E_vIs added to the data acquisition unit DAU.
Voltage data D_vIs converted to The data D_vIs treated like any other data
6 and the differential current data D_dIn process 11 as well
It is rewritten. In processing 13-5, the voltage data D_vTo
To perform an undervoltage relaying process as shown in the following equation.
If the equation holds, the processing result is set to Y. [0159] (Equation 20) Equation (39) shows the piezoelectric data D during a half cycle._vof
The integral value of the absolute value is a constant value K₁₂Detect that
Things. This equation can detect the voltage drop phenomenon
Is well known and will not be described in detail for simplicity.
You. In addition, as undervoltage relay processing, various
Although there are means, they can be used as well. The undervoltage relay processing in this example is usually performed in an internal accident.
And reliable operation in the event of transformer accidents
Then, the processing result is set to Y. Therefore, processing 13-5 is expressed by equation (34).
Instead, it can be applied similarly as undervoltage relay processing
Things. In addition, undervoltage relay processing is usually 0.5 to 1
Since the accident is detected with a delay of less than the cycle,
In case of undervoltage relay processing, processing 13-8 count value
Correct C ″ to about 12. The processing 13-6 can be similarly performed by other means.
Wear. That is, the process 13-6 does not delay the increase of the current at the time of the accident.
For various detections within this range.
I can do it. That is, equation (35) is the positive one of each terminal current data.
Sum data D_pData with the sign of the sum of
D_nUsing the maximum value of
It is to detect the increase with respect to the value. On the other hand, for example, the expression (5) or (6)
Data D_rEven if an increase in current is detected,
Can be detected without delay.
Can be Also, the means for detecting the increase
Not only can it be compared with data between
Things. The processing 13-6 only detects an increase in the current.
Instead of detecting the change.
This change is detected, for example, by using the data of equation (5) or (6).
D_rOr the data D_pAnd -D_nData of the maximum value of
Using data such as data,
To compare with data, such as 3/2 or 2 cycles ago
More can be done. Each terminal current data D_jFor each one or
With the data two cycles before, or 1/2 or 3/2
Compare the data before the cycle with the changed sign
Even so, a change in current can be detected.
A change in current is detected only when the current increases.
It also operates when the current decreases due to accident recovery. I
However, when recovering from an accident, recovery from accident detection is slightly delayed.
It is the same as above, and there is no problem in application. The accident detecting means described above is used in the fifth embodiment.
Not only for other embodiments using accident detection means
It can be used as well. [Ninth Embodiment] In each of the above embodiments, the difference function f (d) is expressed by the equation (1) and the suppression data D
_rTo equation (5) and the suppression function f (r) to equation (9).
I explained it. Other than this,
Detailed explanation is given for simplicity because it can be implemented more easily than the embodiment.
Omitted. That is, the difference function f (d) is expressed by equation (2) or (4).
For example, instead of the equation (1), the function 8
(4) is sufficient. Suppression data D_r(6),
In order to obtain the equations (7) and (8), the calculation of the data of each equation is performed by the processing 7
And process this data
In the eleventh data rewriting process, the processing is the same as in the first embodiment.
Good. Further, the suppression function f (r) is expressed by the following equation (10) or (11).
Or the auxiliary function f (r1) in equation (15), (16) or (17)
In order to make the suppression function f (r) of the expression (13) or (14) using
Required suppression data D_rWas calculated in process 7 as described above.
After that, the auxiliary function f (r1) and the like and the suppression function f (r) are
What is necessary is just to carry out by a number calculation process. [Tenth Embodiment] The tenth embodiment is different from the first embodiment in the function calculation of process 8.
Only the output processing and the comparison means processing of the processing 9 are different. That is,
In the theory 8, the following function is calculated. (Equation 21)         f (d) = | D_dm-D_{d (m-1)}｜ ……………… (40)         f (r) = | D_rm-D_{r (m-1)}｜ ……………… (41) Equation (40) is expressed by (1), (2), and
Equation (41) is the same as equation (4), and equation (41) assumes that the predetermined number p is also 2.
It is equal to the expressions (9), (10) and (11). The details of the process 9 are shown in FIG. First processing
9-1 is performed by the equation (21) or (20) similarly to the first embodiment.
U. If this processing result is Y, the count value is obtained in processing 9-13.
Examine C '. If the count value C 'is 2, the processing 9-2
Signal S_TwoIs set to 1. If the count value C 'is not 2,
Adds 1 to the count value C 'and adds a new count
Value C ', and the signal S_TwoIs set to 0. Processing 9-1
If the processing result of step (N) is N, the count value C 'is calculated in step 9-15.
0 and the signal S in process 9-3_TwoIs set to 0. In the above processing, the processing result of processing 9-1 is continuous.
When it becomes Y, continue the state of Y from the second time
Signal S while_TwoIs set to 1 and in other cases the signal S_TwoSet to 0
Things. In the case of this embodiment, the current transformer is saturated due to an external accident.
Occurs, the differential current data D_dAnd the maximum of the three values of
The difference between the minimum values is almost equal to the difference function f (d) in FIG.
And the value of the difference function f (d) in equation (40) is almost zero.
Lasts at least twice. This allows processing
The processing result of 9-1 becomes 1 continuously for at least two times,
No. S_TwoBecomes 1. In the case of an internal accident, the differential current waveform peak
In the sample near the peak, the value of the difference function f (d) in equation (40) is
May be zero. However, this phenomenon occurred twice in a row.
In the next sample, the difference function f (d)
Becomes sufficiently large. Therefore, the processing result of processing 9-1 is
It does not become Y twice consecutively, and the signal S_TwoBecomes 1
And not. As described above, this embodiment is not suitable for internal accidents.
Stop output does not occur, and it is reliably prevented in an external accident
It generates force and can be applied in the same manner as the other embodiments.
Things. As in the present embodiment, the expression (19) or (20)
The number of means to output the blocking output when the condition is satisfied
The case where p is 3 or more can be appropriately applied. Also, assuming that the predetermined number p is 2, the blocking of the equation (21)
When deriving the function f (s), the functions of the equations (40) and (41)
The rejection function f (s) is obtained from the value according to equation (21).
The value of the rejection function f (s) used in the differential relay means of the process 10 is
For example, the minimum value of the value of equation (21) for two consecutive samples
And This is at least one cycle during an external accident.
Once a time, the value of the difference function f (d) becomes significantly smaller.
Therefore, the value of the blocking function f (d) continuously increases.
On the other hand, in the event of an internal accident,
But the difference function f (d) is small and the value of the blocking function f (s) is
This is because it may become large. Thus the blocking function
To determine the value of f (s) from a plurality of values in equation (21)
The case where the number p is 3 or more can be appropriately applied. [Eleventh Embodiment] The above embodiment calculates the difference function f (d) and the suppression function f (r).
All data of a predetermined number p used for output
θ_sTo be p data sampled continuously
It is. However, this is repeated for p samples
Obtained from any combination of p data in the data exceeding
Processing using the difference function f (d) and the suppression function f (r).
If a blocking output is generated in any combination, the processing 9 is blocked.
It can be used as output. To simplify this means, for example, p = 3
Then, using any three of the four data,
Assuming that the function is calculated, the following means
Conceivable. That is, first of all, four data are replaced with three data
To obtain the value of the difference function f (d),
The value of the successive difference function f (d) is obtained in combination. These differences
Find the minimum value of the value of the number f (d), and give the three minimum values
The suppression function f (r) was determined using the data of
Processing 9 is performed using the value of the function. The four differential current data D_dThe maximum value of
Combination of 3 data excluding and 3 data excluding minimum
The difference function f (d) and the suppression function f (r) are obtained from
First, check the presence or absence of blocking output for both,
If the inhibition output is obtained, use it as the inhibition output of process 9.
There is also a law. In this case, differential current data D_dChanges in
At least three consecutive data are small during an external accident
The frustration output is obtained, and in the event of an internal accident, two data
Is small but large for the other data, so
The same blocking output as when using three samples is obtained.
It is. [Twelfth Embodiment] The twelfth embodiment has a hardware configuration and
The processing 6 and the processing 11 are different. Figure 29
2 shows a hardware configuration of the embodiment. In the figure, the same parts as those in FIG.
No. Also, the main characters such as CB and CT are the same,
Devices with different subscripts, such as 5, 6, etc., are similar devices.
And PT is an instrument transformer, and DF is a differential circuit.
You. This embodiment is different from the above embodiments.
Is as follows. (i) The differential current DF is formed by forming the differential circuit DF._dInput conversion
Container CV_dAnd the quantity of electricity E_dTo the data acquisition unit DAU.
I can. (ii) Input conversion of bus B voltage via instrument transformer PT
Container CV_vAnd the amount of electricity E_vInto a data acquisition device D
Add to AU. (iii) Current transformer CT_FiveAnd CT₆And CT₇And CT₈Secondary
Each circuit is connected in parallel, and the sum of
Force transducer CV_FiveAnd CV₆And the quantity of electricity E_FivePassing
And E₆And is applied to the data acquisition unit DAU. Due to the above difference, the differential current data D_dIs
Electricity E_dObtained more directly. Therefore, until
Unlike the embodiment of the first embodiment, in the process 6, the differential current data D_dCalculation
Outgoing is omitted. The quantity of electricity E_vData D_vWhere
The data is fetched in the processing 6 and rewritten in the processing 11. This de
The data is (3) in the accident detection process 13 as described in the eighth embodiment.
Used when performing undervoltage relay processing as shown in equation 9).
You. The difference in the processing from the first embodiment is as described above. In this embodiment, the electric quantity E₁~ E₆To
Data D converted to digital data₁~ D₆Is the terminal
Flow data D_jIt is acquired and used as. Data D_FivePassing
And D₆Is the data of the sum of the currents at the two terminals, respectively.
In this way, when acquiring data of the sum of the currents of some terminals,
In the present invention, these are also referred to as terminal current data. The above data D_FiveAnd D₆Some ends like
Data of the terminal current data D_jTake as
Obtain in principle a non-power supply terminal (or equivalent)
Terminal). For non-power terminals,
Except when there is an accident outside the terminal and the accident current flows out
The current at the time of the accident is negligible with respect to the current at other terminals.
You. Therefore, except when the fault current flows out, the suppression function f
The contribution to (r) can be calculated using the individual data of the terminal current.
There is almost no difference when using summed data. If the fault current flows, the sum current
Are almost the same as the waveforms of the individual currents.
The value of the suppression function f (r) obtained using the current data is
Value of suppression function f (r) obtained using various current data
Is almost the same as From such a relationship, the situation of the protected section is
Depending on the terminal current data
D_j, Each terminal current data D_jIndividually
Almost the same suppression function f (r) is obtained for
And are equally applicable. Also, the difference
Dynamic current data D_dIs the differential current I as in this embodiment._dThan
The direct acquisition is simply the differential current data D_dAcquisition means
Only changed. As described above, the hardware configuration of each embodiment is
Even in the case of 29, exactly the same as the case of the hardware configuration in FIG.
Applicable. [Thirteenth Embodiment] In all of the above embodiments, the input converter (CV₁Output)
Electricity (E₁) Without removing the DC component of the input current
It was almost faithfully communicated. Remove this DC component
Can be obtained with only the output electricity amount
You. Even if the DC component is removed, the converter is not saturated during an external accident.
Current data D between_dIs almost unchanged.
Can produce a sufficiently high blocking output. In the case of an internal accident involving a DC component, the DC component is excluded.
The change of each data is slightly different from the case of not leaving
You. However, this effect is due to the differential current data D_dAnd each terminal
Current data D_jAppears almost the same as
It can be applied almost in the same manner as the embodiment. [Others] The procedure of the accident initial processing described in the fifth to eighth embodiments of the present invention.
The method is not limited to the present invention.
And this blocking output continues for a while after the internal accident occurs.
It can be applied to all such differential relays. like this
As the differential relay device, for example, the aforementioned Japanese Patent Publication No. 57-501 is used.
No. 30, etc. Also, various suppression functions f (r) described in the present invention are used.
Is applicable not only to the present invention but also to other differential relays. That
Example is differential current data D_dIs a waveform that spans both positive and negative
When the data D_dIs positive or negative
The suppression function f (r) in the judgment of the level to detect
Let it. Also, the differential current data D_dIs the suppression function f (r)
To detect and block very small periods of time
It is also possible. [0194] As described above, the present invention can be applied to external accidents.
There is no risk of malfunction even if the current transformer is saturated,
Therefore, it works reliably,
Even if an accident occurs, there is no risk of delay in operation
It is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a basic configuration of the present invention. FIG. 2 is a diagram showing a current waveform when a current transformer is saturated. FIG. 3 is a diagram showing a current waveform at the time of an internal accident following an external accident. FIG. 4 shows a current waveform when a current transformer is saturated during an external accident and a response diagram of the present device. FIG. 5 is a response diagram when a difference function, a suppression function, and other conditions are changed. FIG. 6 is a response diagram when a difference function, a suppression function, and other conditions are changed. FIG. 7 is a response diagram when the difference function, the suppression function, and other conditions are changed. FIG. 8 is a response diagram when the difference function, the suppression function, and other conditions are changed. FIG. 9 is a diagram showing a response of the present invention when the current transformer is not saturated due to an internal accident. FIG. 10 is a diagram showing a response according to the present invention when an accident current flows through only one terminal and a current transformer is saturated in an internal accident. FIG. 11 is a diagram showing a response of the present invention when a current transformer at some terminals into which an accident current flows due to an internal accident is saturated and current transformers at other terminals are not saturated. FIG. 12 is a diagram showing a response of the present invention when a current transformer at some terminals into which an accident current flows due to an internal accident is saturated and current transformers at other terminals are not saturated. FIG. 13 is a diagram showing a hardware configuration according to the first embodiment of the present invention. FIG. 14 is a diagram showing a processing flow of the first embodiment of the present invention. FIG. 15 is a flowchart showing details of a process 9 in the first embodiment of the present invention. FIG. 16 is a flowchart showing details of a process 10 according to the first embodiment of the present invention. FIG. 17 is a flowchart showing details of a process 10 according to the second embodiment of the present invention. FIG. 18 is a flowchart showing details of a process 10 according to the third embodiment of the present invention. FIG. 19 is a flowchart showing details of a process 9 in the fourth embodiment of the present invention. FIG. 20 is a flowchart showing details of a process 10 according to the fourth embodiment of the present invention. FIG. 21 is a flowchart showing processing according to a fifth embodiment of the present invention. FIG. 22 is a flowchart showing details of a process 12 according to the fifth embodiment of the present invention. FIG. 23 is a flowchart showing details of a process 13 according to the fifth embodiment of the present invention. FIG. 24 is a flowchart showing details of a process 9 in the sixth embodiment of the present invention. FIG. 25 is a flowchart showing processing of a seventh embodiment of the present invention. FIG. 26 is a flowchart showing details of a process 14 according to the seventh embodiment of the present invention. FIG. 27 is a flowchart showing details of a process 13 in the eighth embodiment of the present invention. FIG. 28 is a flowchart showing details of a process 9 in the tenth embodiment of the present invention. FIG. 29 is a diagram showing a hardware configuration according to a twelfth embodiment of the present invention. [Description of Reference Numerals] B bus CB ₁ to CB _n breaker CT ₁ to CT _n transformer PT instrument transformer CV ₁ ~CV _n, CV _v and CV _d input transducer DAU data obtainer CPU processor OU Output apparatus

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02H 3/26-3/30

Claims (1)

(57) [Claims] Each terminal current I _{j (j} = 1~n) sampled at predetermined time intervals, which takes each terminal current data D _j obtained by converting into digital data, adds the respective terminal current data D _j , to create a differential current data D _d, or the differential current I _d of each terminal and sampled at predetermined time intervals, a differential current to create a differential current data D _d and converts it into digital data a data creating means, a plurality of different predetermined number of sampling time the differential current data D _d consecutive place
The absolute value of the difference between the maximum and minimum values of a fixed number of data
Is the sum of a predetermined number of consecutive absolute values of the difference between the values of two data adjacent to each other at the sampling time, or
A predetermined number of consecutive absolute values of the difference between the values of two adjacent data
Calculate one of the maximum values of the number and use it as the value of the difference function f (d).
A differential function calculating means that the maximum value of the samples in one or more cycles of a predetermined period the differential current data D _d or,
Calculating one of a sum of the absolute value of the differential current data D _d
To the value of the suppression amount data _Dr , and this different suppression amount _Dr
Is the difference between the maximum and minimum values of a predetermined number of consecutive data
In other words, a series of absolute values of the difference between two adjacent values of the sample value
Calculates one of the maximum values of the following number
suppression function calculation means for setting the value of f (r) , comparison means for generating a blocking output when the value of the difference function f (d) is smaller than the value of the suppression function f (r) , and operation by the blocking output of the comparison means A differential relay device comprising: a differential relay unit that is suppressed so as to prevent the differential relay device.