CN107102192B - A kind of full phase asynchronous oscillation method of discrimination and device - Google Patents
A kind of full phase asynchronous oscillation method of discrimination and device Download PDFInfo
- Publication number
- CN107102192B CN107102192B CN201710296997.3A CN201710296997A CN107102192B CN 107102192 B CN107102192 B CN 107102192B CN 201710296997 A CN201710296997 A CN 201710296997A CN 107102192 B CN107102192 B CN 107102192B
- Authority
- CN
- China
- Prior art keywords
- oscillation
- phase
- current
- condition
- sum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 230000010355 oscillation Effects 0.000 title claims abstract description 224
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000000926 separation method Methods 0.000 claims description 19
- 238000005070 sampling Methods 0.000 claims description 10
- 238000004364 calculation method Methods 0.000 claims description 3
- 230000007257 malfunction Effects 0.000 abstract 1
- 238000004088 simulation Methods 0.000 description 2
- 206010033799 Paralysis Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000012850 discrimination method Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/02—Measuring effective values, i.e. root-mean-square values
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Phase Differences (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention relates to a kind of full phase asynchronous oscillation method of discrimination and device, method of discrimination therein includes: to judge whether to meet the entry condition that full phase asynchronous oscillation differentiates；If meeting entry condition, judge Out-of-Step Splitting Systems element when three-phase phase current negative-sequence current I2With the three-phase phase current maximum effective peak I in each cycle of oscillationHmaxBetween whether meet setting condition；It imposes a condition if meeting, is judged as full phase asynchronous oscillation；Otherwise it is determined as non-three phase asynchronous oscillation.The present invention is under the premise of meeting the entry condition that full phase asynchronous oscillation differentiates, whether the difference between the three-phase phase current peak-peak in negative-sequence current and each cycle of oscillation by judging Out-of-Step Splitting Systems element meets setting condition, can quick and precisely determine whether full phase asynchronous oscillation, the tripping of Out-of-Step Splitting Systems policy device and malfunction are avoided, the accuracy of Out-of-Step Splitting Systems strategy is improved.
Description
Technical Field
The invention relates to a method and a device for judging full-phase asynchronous oscillation, and belongs to the technical field of relay protection of power systems.
Background
The out-of-step separation strategy device is particularly important to be used as a third line of defense for the safety protection of the power system. The out-of-step disconnection strategy means also cannot act on the way the power system allows for non-full phase operation. If the condition of misoperation or refusal operation occurs, a fatal disaster is brought to the power grid of the power system, and the large-area paralysis of the power grid is caused.
Therefore, in the out-of-step separation strategy device, whether full-phase asynchronous oscillation exists or not is quickly and accurately identified, and reliable basis is provided for the action of the out-of-step separation strategy device, so that the out-of-step separation strategy device is prevented from being operated mistakenly or refused to be operated, and the out-of-step separation strategy device becomes an important problem in power system maintenance.
Disclosure of Invention
The invention aims to provide a method and a device for judging full-phase asynchronous oscillation, which are used for solving the problem of poor action reliability of an out-of-step splitting strategy device caused by inaccurate judgment of the full-phase asynchronous oscillation in the out-of-step splitting strategy device.
In order to solve the technical problem, the invention provides a method for judging full-phase asynchronous oscillation, which comprises the following steps:
step 1, judging whether a starting condition of full-phase asynchronous oscillation judgment is met;
step 2, if the starting condition is met, judging the negative sequence current I of the current three-phase current of the out-of-step separating element2With the maximum effective peak value I of the three-phase current in each oscillation periodHmaxWhether a set condition is met or not is shown as the following expression:
I2≤keIHmax
wherein k iseRepresenting a maximum phase current threshold coefficient per oscillation period;
and step 3: if the set conditions are met, judging the oscillation to be full-phase asynchronous oscillation; otherwise, judging the oscillation as non-full-phase asynchronous oscillation.
Further, ke∈(0.08,0.15)。
Further, the method for judging whether the starting condition of the full-phase asynchronous oscillation judgment is met comprises the following steps:
step 1-1, obtaining three-phase current I of out-of-step disconnection elementA、IBAnd ICAnd three phase voltage UA、UBAnd UCThe sampling value of (2);
step 1-2, calculating the effective value I of the current three-phase current of the out-of-step disconnection elementAtmp、IBtmpAnd ICtmpMaximum value I of current three-phase current effective valuemaxThe sum of the current three-phase active power PtmpThe sum P of three-phase active power before T seconds-TThree-phase memory sum of active power P0The number of times of sliding pole of oscillation N with the type of the number of times of sliding pole of x in the current oscillation periodxAnd the sliding pole number N of the oscillation with the sliding pole number type x in the first N oscillation periods-n x，x∈[0,1,2]；
Step 1-3, judging the following conditions:
condition 1: i ismax、Nx、N-n xAnd P-TNot less than the respective corresponding threshold;
condition 2: sum P of current three-phase active powertmpAnd the sum P of the three-phase active power before T seconds-TThe absolute value of the difference value of (a) is greater than a set value;
condition 3: the number N of sliding pole times of oscillation with the type x of the sliding pole times in the current oscillation periodxThe number N of the sliding pole times of the oscillation with the sliding pole time type x in the first N oscillation periods-n xThe difference value of (a) is greater than a set value;
condition 4: sum P of current three-phase active powertmpAnd sum of three-phase memory active power P0The product between is less than the set value;
and if all the conditions are met, judging that the starting condition of the all-phase asynchronous oscillation judgment is met.
Further, taking T as 5 and n as 1, the discrimination formula of the condition 1 is:
wherein k ismaxE (0.4,0.6) represents the threshold coefficient of the oscillating current, InFor out-of-step separating elements corresponding to current rating of CT, IAtmp、IBtmpAnd ICtmpRespectively representing the effective values of the current three-phase currents of the out-of-step splitting elements, ImaxMaximum value, P, representing the effective value of the current three-phase current of the out-of-step disconnected element-TIs the sum of three-phase active power P before T seconds of elementsetE (0,1000) is a set threshold, N, of the sum of the three-phase active power T seconds before the out-of-step disconnection elementxThe number of sliding poles of oscillation with the type of the number of sliding poles in the current oscillation period being x is N-n xThe number of the sliding pole times is the number of the sliding pole times of the oscillation with the type of x in the first n oscillation periods;
the discrimination formula of the condition 2 is:
|Ptmp-P-T|＞ΔPset
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P-TIs the sum of three-phase active power before T seconds of out-of-step disconnection element, delta PsetE (0,1000) setting a threshold for the power jump of the out-of-step disconnection element;
the discrimination formula of the condition 3 is:
Nx≥N-n x＞1
wherein x is ∈ [0,1,2 ]]The type of the number of sliding poles per oscillation period is shown, and x is respectively shown when x is 0,1 and 2: number of times of pole slipping at oscillation center, number of times of pole slipping in forward direction and number of times of pole slipping in reverse direction, NxFor the type of the number of sliding-pole times of oscillation of x in the current oscillation cycle of the out-of-step disconnected element, N-n xThe number of times of sliding poles in the first n oscillation periods of the out-of-step separation element is the number of times of oscillation sliding poles with the type of x;
the discrimination formula of the condition 4 is:
Ptmp*P0＜0
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P0The sum of the three-phase memory active power of the out-of-step disconnection element is obtained.
Further, the oscillation slide pole number N with the slide pole number type x in the current oscillation period is calculatedxThe method comprises the following steps:
(1) calculating a power angle phi of the current apparent power according to the current three-phase voltage and three-phase current sampling values of the out-of-step splitting element;
(2) calculating an angle area and a crossing mode of the power angle phi crossing according to a power phase angle principle;
(3) according to the angle region and the crossing mode of the power angle phi crossing, the oscillation slide pole number N with the slide pole number type x in the current oscillation period is calculatedx；
Calculating the maximum effective peak value I of the three-phase current in each oscillation periodHmaxThe method comprises the following steps:
when for any slide number type x, if anyUpdating the maximum effective peak value I of the three-phase current in the local oscillation periodHmax(ii) a Otherwise, keep IHmaxThe maximum effective peak value of the three-phase current in the last oscillation period is obtained; wherein,
the invention also provides a device for judging full-phase asynchronous oscillation, which comprises:
a start judging module: judging whether a starting condition for judging the full-phase asynchronous oscillation is met;
condition judging moduleBlock (2): if the starting condition is met, judging the negative sequence current I of the current three-phase current of the out-of-step separating element2With the maximum effective peak value I of the three-phase current in each oscillation periodHmaxWhether a set condition is met or not is shown as the following expression:
I2≤keIHmax
wherein k iseRepresenting a maximum phase current threshold coefficient per oscillation period;
and a result judging module: if the set conditions are met, judging the oscillation to be full-phase asynchronous oscillation; otherwise, judging the oscillation as non-full-phase asynchronous oscillation.
Further, ke∈(0.08,0.15)。
Further, the start judging module includes:
a data acquisition unit: three-phase current I for obtaining out-of-step separating elementA、IBAnd ICAnd three phase voltage UA、UBAnd UCThe sampling value of (2);
a data calculation unit: effective value I for calculating current three-phase current of out-of-step disconnection elementAtmp、IBtmpAnd ICtmpMaximum value I of current three-phase current effective valuemaxThe sum of the current three-phase active power PtmpThe sum P of three-phase active power before T seconds-TThree-phase memory sum of active power P0The number of times of sliding pole of oscillation N with the type of the number of times of sliding pole of x in the current oscillation periodxAnd the sliding pole number N of the oscillation with the sliding pole number type x in the first N oscillation periods-n x，x∈[0,1,2]；
A condition judgment unit: for judging the following conditions:
condition 1: i ismax、Nx、N-n xAnd P-TNot less than the respective corresponding threshold;
condition 2: sum P of current three-phase active powertmpAnd the sum P of the three-phase active power before T seconds-TThe absolute value of the difference value of (a) is greater than a set value;
condition 3: the number N of sliding pole times of oscillation with the type x of the sliding pole times in the current oscillation periodxThe number N of the sliding pole times of the oscillation with the sliding pole time type x in the first N oscillation periods-n xThe difference value of (a) is greater than a set value;
condition 4: sum P of current three-phase active powertmpAnd sum of three-phase memory active power P0The product between is less than the set value;
and if all the conditions are met, judging that the starting condition of the all-phase asynchronous oscillation judgment is met.
Further, taking T as 5 and n as 1, the discrimination formula of the condition 1 is:
wherein k ismaxE (0.4,0.6) represents the threshold coefficient of the oscillating current, InFor out-of-step separating elements corresponding to current rating of CT, IAtmp、IBtmpAnd ICtmpRespectively representing the effective values of the current three-phase currents of the out-of-step splitting elements, ImaxMaximum value, P, representing the effective value of the current three-phase current of the out-of-step disconnected element-TIs the sum of three-phase active power P before T seconds of elementsetE (0,1000) is a set threshold, N, of the sum of the three-phase active power T seconds before the out-of-step disconnection elementxThe number of sliding poles of oscillation with the type of the number of sliding poles in the current oscillation period being x is N-n xThe number of the sliding pole times is the number of the sliding pole times of the oscillation with the type of x in the first n oscillation periods;
the discrimination formula of the condition 2 is:
|Ptmp-P-T|＞ΔPset
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P-TIs the sum of three-phase active power before T seconds of out-of-step disconnection element, delta PsetE (0,1000) setting a threshold for the power jump of the out-of-step disconnection element;
the discrimination formula of the condition 3 is:
Nx≥N-n x＞1
wherein x is ∈ [0,1,2 ]]The type of the number of sliding poles per oscillation period is shown, and x is respectively shown when x is 0,1 and 2: number of times of pole slipping at oscillation center, number of times of pole slipping in forward direction and number of times of pole slipping in reverse direction, NxFor the type of the number of sliding-pole times of oscillation of x in the current oscillation cycle of the out-of-step disconnected element, N-n xThe number of times of sliding poles in the first n oscillation periods of the out-of-step separation element is the number of times of oscillation sliding poles with the type of x;
the discrimination formula of the condition 4 is:
Ptmp*P0＜0
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P0The sum of the three-phase memory active power of the out-of-step disconnection element is obtained.
Further, in the data calculation unit, the oscillation slide pole number N of which the slide pole number type is x in the current oscillation period is calculatedxThe method comprises the following steps:
(1) calculating a power angle phi of the current apparent power according to the current three-phase voltage and three-phase current sampling values of the out-of-step splitting element;
(2) calculating an angle area and a crossing mode of the power angle phi crossing according to a power phase angle principle;
(3) according to the angle region and the crossing mode of the power angle phi crossing, the oscillation slide pole number N with the slide pole number type x in the current oscillation period is calculatedx；
In the condition judging module, the maximum effective peak value I of the three-phase current in each oscillation period is calculatedHmaxThe method comprises the following steps:
when for any slide number type x, if anyUpdating the maximum effective peak value I of the three-phase current in the local oscillation periodHmax(ii) a Otherwise, keep IHmaxThe maximum effective peak value of the three-phase current in the last oscillation period is obtained; wherein,
the invention has the beneficial effects that: on the premise of meeting the starting condition of the full-phase asynchronous oscillation judgment, whether full-phase asynchronous oscillation exists or not can be judged quickly and accurately by judging whether the difference between the negative sequence current of the out-of-step separating element and the maximum peak value of the three-phase current in each oscillation period meets the set condition or not; if the oscillation is judged to be full-phase asynchronous oscillation, the out-of-step separation strategy is opened, and the device of the out-of-step separation strategy is prevented from refusing to operate; and if the asynchronous oscillation is judged to be not full-phase asynchronous oscillation, the out-of-step separation strategy is locked, so that the maloperation of an out-of-step separation strategy device is avoided, and the accuracy of the out-of-step separation strategy is obviously improved.
Drawings
FIG. 1 is a flow chart of a method of discrimination of full phase asynchronous oscillations;
FIG. 2 is a simulation graph of negative sequence current and maximum peak characteristics during full-phase asynchronous oscillation;
FIG. 3 is a simulation graph of negative sequence current versus maximum peak characteristics for non-full phase asynchronous oscillations.
Detailed Description
The invention is described in detail below with reference to the figures and specific examples.
The invention provides a method for judging full-phase asynchronous oscillation, wherein a judging flow chart is shown in figure 1, and the method specifically comprises the following steps:
and step A, judging whether the starting condition of the full-phase asynchronous oscillation judgment is met.
The method for judging whether the starting condition of the full-phase asynchronous oscillation judgment is met comprises the following steps:
step 1-1, obtaining three-phase current I of out-of-step disconnection elementA、IBAnd ICAnd three phase voltage UA、UBAnd UCOf the sampling value(s).
Step 1-2, calculating the effective value I of the current three-phase current of the out-of-step disconnection elementAtmp、IBtmpAnd ICtmpMaximum value I of current three-phase current effective valuemaxThe sum of the current three-phase active power PtmpThe sum P of three-phase active power before T seconds-TThree-phase memory sum of active power P0The number of times of sliding pole of oscillation N with the type of the number of times of sliding pole of x in the current oscillation periodxAnd the sliding pole number N of the oscillation with the sliding pole number type x in the first N oscillation periods-n x，x∈[0,1,2]。
The out-of-step disconnection element refers to a line element, and may also refer to a line.
Step 1-3, judging the following conditions:
condition 1: i ismax、Nx、N-n xAnd P-TNot less than the respective corresponding threshold, the discrimination formula is:
wherein k ismaxThe epsilon (0.4,0.6) represents an oscillating current threshold coefficient, and the values can be specifically 0.4, 0.5, 0.6 and the like; i isnFor out-of-step separating elements corresponding to current rating of CT, IAtmp、IBtmpAnd ICtmpRespectively representing the effective values of the current three-phase currents of the out-of-step splitting elements, ImaxEffective value I of current three-phase current representing out-of-step disconnection elementAtmp、IBtmpAnd ICtmpMaximum value of (1), P-TIs the sum of three-phase active power P before T seconds of elementsetE (0,1000) is a set threshold, N, of the sum of the three-phase active power T seconds before the out-of-step disconnection elementxThe number of sliding poles of oscillation with the type of the number of sliding poles in the current oscillation period being x is N-n xThe type of the pole slipping times in the first n oscillation periods is the oscillation pole slipping times of x.
Condition 2: sum P of current three-phase active powertmpAnd the sum P of the three-phase active power before T seconds-TThe absolute value of the difference value is larger than a set value, and the discrimination formula is as follows:
|Ptmp-P-T|＞ΔPset
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P-TIs the sum of three-phase active power before T seconds of out-of-step disconnection element, delta PsetE (0,1000) sets a threshold for the power jump of the out-of-step disconnect element.
Condition 3: the number N of sliding pole times of oscillation with the type x of the sliding pole times in the current oscillation periodxThe number N of the sliding pole times of the oscillation with the sliding pole time type x in the first N oscillation periods-n xThe difference value is greater than the set value, and the discrimination formula is as follows:
Nx≥N-n x＞1
wherein x is ∈ [0,1,2 ]]The type of the number of sliding poles per oscillation period is shown, and x is respectively shown when x is 0,1 and 2: number of times of pole slipping at oscillation center, number of times of pole slipping in forward direction and number of times of pole slipping in reverse directionNumber of pole slipping directions, NxFor the type of the number of sliding-pole times of oscillation of x in the current oscillation cycle of the out-of-step disconnected element, N-n xThe number of times of sliding pole in the first n oscillation periods of the out-of-step separation element is the oscillation sliding pole number of type x.
Specifically, the number N of sliding pole times of oscillation with the type x of the sliding pole times in the current oscillation period is calculatedxThe method comprises the following steps:
(1) calculating a power angle phi of the current apparent power according to the current three-phase voltage and three-phase current sampling values of the out-of-step splitting element;
(2) calculating an angle area and a crossing mode of the power angle phi crossing according to a power phase angle principle;
(3) according to the angle region and the crossing mode of the power angle phi crossing, the oscillation slide pole number N with the slide pole number type x in the current oscillation period is calculatedx。
Condition 4: sum P of current three-phase active powertmpAnd sum of three-phase memory active power P0The product of the two is less than a set value, and the discrimination formula is as follows:
Ptmp*P0＜0
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P0The sum of the three-phase memory active power of the out-of-step disconnection element is obtained.
And if all the conditions are met, judging that the starting condition of the all-phase asynchronous oscillation judgment is met.
Step B, if the starting condition is met, judging the negative sequence current I of the current three-phase current of the out-of-step separating element2With the maximum effective peak value I of the three-phase current in each oscillation periodHmaxWhether the set conditions are met or not is judged by the following formula:
I2≤keIHmax
wherein, I2Negative sequence current, k, of the current three-phase current for out-of-step splitting elementseRepresenting the threshold coefficient, k, of the maximum phase current per oscillation periodeE (0.08,0.15), specifically, keCan be equal to 0.08, 0.10, 0.15; i isHmaxThe maximum effective peak value of the three-phase current in each oscillation period of the out-of-step separation element.
Specifically, the maximum effective peak value I of the three-phase current in each oscillation period is calculatedHmaxThe method comprises the following steps: when for any slide number type x, if anyUpdating the maximum effective peak value I of the three-phase current in the local oscillation periodHmax(ii) a Otherwise, keep IHmaxThe maximum effective peak value of the three-phase current in the last oscillation period is obtained; wherein,
in this embodiment, T is 5, n is 1, and T and n may also take other reasonable values without affecting the determination result, such as: t may be a positive integer of 3, 4 or 6, etc., and n may be a positive integer of 2, 3, 4, etc.
It should be noted that this embodiment only shows that the starting conditions 1-4 and I are satisfied2And IHmaxA specific expression satisfying the set condition, but is not limited to the given discrimination formula, and includes various variations of the above discrimination formula.
And C: if the set conditions are met, judging the oscillation to be full-phase asynchronous oscillation; otherwise, judging the oscillation as non-full-phase asynchronous oscillation.
That is, when the difference between the negative sequence current of the out-of-step separating element and the maximum peak value of the three-phase current in each oscillation period meets the set condition, the slide pole count of the out-of-step separating element is increased, and other electrical parameters meet the set condition, the out-of-step separating element is judged to be full-phase asynchronous oscillation; and when the difference between the negative sequence current of the out-of-step separating element and the maximum peak value of the three-phase current in each oscillation period does not meet the set condition, the slide pole count of the out-of-step separating element is increased, and other electrical parameters meet the set condition, judging that the out-of-phase asynchronous oscillation is not full-phase asynchronous oscillation. In the case of full-phase asynchronous oscillation, the simulated change of the negative sequence current of the out-of-step separating element and the maximum peak value of the three-phase current in each oscillation period is shown in fig. 2, and in the case of non-full-phase asynchronous oscillation, the simulated change of the negative sequence current of the out-of-step separating element and the maximum peak value of the three-phase current in each oscillation period is shown in fig. 3.
When the judgment result is that the oscillation is full-phase asynchronous oscillation or not, a basis can be provided for reliable action of the out-of-step separation strategy device, namely, when the judgment result is that the oscillation is full-phase asynchronous oscillation, the device separation strategy is opened; and when the oscillation is judged to be not full-phase asynchronous oscillation, the locking device is subjected to the disconnection strategy.
The invention also provides a device for judging full-phase asynchronous oscillation, which comprises:
a start judging module: judging whether a starting condition for judging the full-phase asynchronous oscillation is met;
a condition judgment module: if the starting condition is met, judging the negative sequence current I of the current three-phase current of the out-of-step separating element2With the maximum effective peak value I of the three-phase current in each oscillation periodHmaxWhether a set condition is met or not is shown as the following expression:
I2≤keIHmax
wherein k iseRepresenting a maximum phase current threshold coefficient per oscillation period;
and a result judging module: if the set conditions are met, judging the oscillation to be full-phase asynchronous oscillation; otherwise, judging the oscillation as non-full-phase asynchronous oscillation.
The discrimination device is actually a computer solution based on the above all-phase asynchronous oscillation discrimination method, namely a software framework, and the software can be operated in the out-of-step separation strategy device equipment. Since the above-mentioned method for determining the fully-phased asynchronous oscillation is described clearly and completely, each unit in the apparatus will not be described in detail.
Claims (10)
1. A method for judging full-phase asynchronous oscillation is characterized by comprising the following steps:
step 1, judging whether a starting condition of full-phase asynchronous oscillation judgment is met;
step 2, if the starting condition is met, judging the negative sequence current I of the current three-phase current of the out-of-step separating element2With the maximum effective peak value I of the three-phase current in each oscillation periodHmaxWhether a set condition is met or not is shown as the following expression:
I2≤keIHmax
wherein k iseRepresenting a maximum phase current threshold coefficient per oscillation period;
and step 3: if the set conditions are met, judging the oscillation to be full-phase asynchronous oscillation; otherwise, judging the oscillation as non-full-phase asynchronous oscillation.
2. The method according to claim 1, wherein k is ke∈(0.08,0.15)。
3. The method for judging full-phase asynchronous oscillation according to claim 1 or 2, wherein the method for judging whether the starting condition for judging full-phase asynchronous oscillation is satisfied comprises:
step 1-1, obtaining three-phase current I of out-of-step disconnection elementA、IBAnd ICAnd three phase voltage UA、UBAnd UCThe sampling value of (2);
step 1-2, calculating the effective value I of the current three-phase current of the out-of-step disconnection elementAtmp、IBtmpAnd ICtmpMaximum value I of current three-phase current effective valuemaxThe sum of the current three-phase active power PtmpThe sum P of three-phase active power before T seconds-TThree-phase memory sum of active power P0The number of times of sliding pole of oscillation N with the type of the number of times of sliding pole of x in the current oscillation periodxAnd the sliding pole number N of the oscillation with the sliding pole number type x in the first N oscillation periods-n x，x∈[0,1,2]；
Step 1-3, judging the following conditions:
condition 1: i ismax、Nx、N-n xAnd P-TNot less than the respective corresponding threshold;
condition 2: sum P of current three-phase active powertmpAnd the sum P of the three-phase active power before T seconds-TThe absolute value of the difference value of (a) is greater than a set value;
condition 3: the number N of sliding pole times of oscillation with the type x of the sliding pole times in the current oscillation periodxAnd front nNumber of times N of sliding pole oscillation with type x of sliding pole number in each oscillation period-n xThe difference value of (a) is greater than a set value;
condition 4: sum P of current three-phase active powertmpAnd sum of three-phase memory active power P0The product between is less than the set value;
and if all the conditions are met, judging that the starting condition of the all-phase asynchronous oscillation judgment is met.
4. The method according to claim 3, wherein T-5 and n-1 are taken, and the criterion formula of the condition 1 is:
wherein k ismaxE (0.4,0.6) represents the threshold coefficient of the oscillating current, InFor out-of-step separating elements corresponding to current rating of CT, IAtmp、IBtmpAnd ICtmpRespectively representing the effective values of the current three-phase currents of the out-of-step splitting elements, ImaxMaximum value, P, representing the effective value of the current three-phase current of the out-of-step disconnected element-TIs the sum of three-phase active power P before T seconds of elementsetE (0,1000) is a set threshold, N, of the sum of the three-phase active power T seconds before the out-of-step disconnection elementxThe number of sliding poles of oscillation with the type of the number of sliding poles in the current oscillation period being x is N-n xThe number of the sliding pole times is the number of the sliding pole times of the oscillation with the type of x in the first n oscillation periods;
the discrimination formula of the condition 2 is:
|Ptmp-P-T|＞ΔPset
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P-TIs the sum of three-phase active power before T seconds of out-of-step disconnection element, delta PsetE (0,1000) setting a threshold for the power jump of the out-of-step disconnection element;
the discrimination formula of the condition 3 is:
Nx≥N-n x＞1
wherein x is ∈ [0,1,2 ]]The type of the number of sliding poles per oscillation period is shown, and x is respectively shown when x is 0,1 and 2: number of times of pole slipping at oscillation center, number of times of pole slipping in forward direction and number of times of pole slipping in reverse direction, NxFor the type of the number of sliding-pole times of oscillation of x in the current oscillation cycle of the out-of-step disconnected element, N-n xThe number of times of sliding poles in the first n oscillation periods of the out-of-step separation element is the number of times of oscillation sliding poles with the type of x;
the discrimination formula of the condition 4 is:
Ptmp*P0＜0
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P0The sum of the three-phase memory active power of the out-of-step disconnection element is obtained.
5. The method according to claim 3, wherein the number N of sliding pole times of oscillation with the type x of sliding pole times in the current oscillation period is calculatedxThe method comprises the following steps:
(1) calculating a power angle phi of the current apparent power according to the current three-phase voltage and three-phase current sampling values of the out-of-step splitting element;
(2) calculating an angle area and a crossing mode of the power angle phi crossing according to a power phase angle principle;
(3) according to the angle region and the crossing mode of the power angle phi crossing, the oscillation slide pole number N with the slide pole number type x in the current oscillation period is calculatedx；
Calculating the maximum effective peak value I of the three-phase current in each oscillation periodHmaxThe method comprises the following steps:
when for any slide number type x, if anyUpdating the maximum effective peak value I of the three-phase current in the local oscillation periodHmax(ii) a Otherwise, keep IHmaxFor the three-phase in the last oscillation periodA maximum effective peak current value; wherein,
6. an apparatus for discriminating full-phase asynchronous oscillation, comprising:
a start judging module: judging whether a starting condition for judging the full-phase asynchronous oscillation is met;
a condition judgment module: if the starting condition is met, judging the negative sequence current I of the current three-phase current of the out-of-step separating element2With the maximum effective peak value I of the three-phase current in each oscillation periodHmaxWhether a set condition is met or not is shown as the following expression:
I2≤keIHmax
wherein k iseRepresenting a maximum phase current threshold coefficient per oscillation period;
and a result judging module: if the set conditions are met, judging the oscillation to be full-phase asynchronous oscillation; otherwise, judging the oscillation as non-full-phase asynchronous oscillation.
7. The device according to claim 6, wherein k is ke∈(0.08,0.15)。
8. The apparatus according to claim 6 or 7, wherein the start-up determining module comprises:
a data acquisition unit: three-phase current I for obtaining out-of-step separating elementA、IBAnd ICAnd three phase voltage UA、UBAnd UCThe sampling value of (2);
a data calculation unit: effective value I for calculating current three-phase current of out-of-step disconnection elementAtmp、IBtmpAnd ICtmpMaximum value I of current three-phase current effective valuemaxThe sum of the current three-phase active power PtmpThe sum P of three-phase active power before T seconds-TThree-phase memory sum of active power P0The number of times of sliding pole of oscillation N with the type of the number of times of sliding pole of x in the current oscillation periodxAnd the sliding pole number N of the oscillation with the sliding pole number type x in the first N oscillation periods-n x，x∈[0,1,2]；
A condition judgment unit: for judging the following conditions:
condition 1: i ismax、Nx、N-n xAnd P-TNot less than the respective corresponding threshold;
condition 2: sum P of current three-phase active powertmpAnd the sum P of the three-phase active power before T seconds-TThe absolute value of the difference value of (a) is greater than a set value;
condition 3: the number N of sliding pole times of oscillation with the type x of the sliding pole times in the current oscillation periodxThe number N of the sliding pole times of the oscillation with the sliding pole time type x in the first N oscillation periods-n xThe difference value of (a) is greater than a set value;
condition 4: sum P of current three-phase active powertmpAnd sum of three-phase memory active power P0The product between is less than the set value;
and if all the conditions are met, judging that the starting condition of the all-phase asynchronous oscillation judgment is met.
9. The device for determining full-phase asynchronous oscillation according to claim 8, wherein T-5 and n-1 are taken, and the determination formula of the condition 1 is:
wherein k ismaxE (0.4,0.6) represents the threshold coefficient of the oscillating current, InFor out-of-step separating elements corresponding to current rating of CT, IAtmp、IBtmpAnd ICtmpRespectively representing the effective values of the current three-phase currents of the out-of-step splitting elements, ImaxMaximum value, P, representing the effective value of the current three-phase current of the out-of-step disconnected element-TIs a unit ofSum of three-phase active power P before T secondssetE (0,1000) is a set threshold, N, of the sum of the three-phase active power T seconds before the out-of-step disconnection elementxThe number of sliding poles of oscillation with the type of the number of sliding poles in the current oscillation period being x is N-n xThe number of the sliding pole times is the number of the sliding pole times of the oscillation with the type of x in the first n oscillation periods;
the discrimination formula of the condition 2 is:
|Ptmp-P-T|＞ΔPset
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P-TIs the sum of three-phase active power before T seconds of out-of-step disconnection element, delta PsetE (0,1000) setting a threshold for the power jump of the out-of-step disconnection element;
the discrimination formula of the condition 3 is:
Nx≥N-n x＞1
wherein x is ∈ [0,1,2 ]]The type of the number of sliding poles per oscillation period is shown, and x is respectively shown when x is 0,1 and 2: number of times of pole slipping at oscillation center, number of times of pole slipping in forward direction and number of times of pole slipping in reverse direction, NxFor the type of the number of sliding-pole times of oscillation of x in the current oscillation cycle of the out-of-step disconnected element, N-n xThe number of times of sliding poles in the first n oscillation periods of the out-of-step separation element is the number of times of oscillation sliding poles with the type of x;
the discrimination formula of the condition 4 is:
Ptmp*P0＜0
wherein, PtmpIs the sum of the active power of the three phases present of the out-of-step disconnected element, P0The sum of the three-phase memory active power of the out-of-step disconnection element is obtained.
10. The device according to claim 8, wherein the data calculating unit calculates the number N of sliding pole times of oscillation in which the type of sliding pole times in the current oscillation period is xxThe method comprises the following steps:
(1) calculating a power angle phi of the current apparent power according to the current three-phase voltage and three-phase current sampling values of the out-of-step splitting element;
(2) calculating an angle area and a crossing mode of the power angle phi crossing according to a power phase angle principle;
(3) according to the angle region and the crossing mode of the power angle phi crossing, the oscillation slide pole number N with the slide pole number type x in the current oscillation period is calculatedx；
In the condition judging module, the maximum effective peak value I of the three-phase current in each oscillation period is calculatedHmaxThe method comprises the following steps:
when for any slide number type x, if anyUpdating the maximum effective peak value I of the three-phase current in the local oscillation periodHmax(ii) a Otherwise, keep IHmaxThe maximum effective peak value of the three-phase current in the last oscillation period is obtained; wherein,
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710296997.3A CN107102192B (en) | 2017-04-28 | 2017-04-28 | A kind of full phase asynchronous oscillation method of discrimination and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710296997.3A CN107102192B (en) | 2017-04-28 | 2017-04-28 | A kind of full phase asynchronous oscillation method of discrimination and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107102192A CN107102192A (en) | 2017-08-29 |
| CN107102192B true CN107102192B (en) | 2019-07-23 |
Family
ID=59657911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710296997.3A Expired - Fee Related CN107102192B (en) | 2017-04-28 | 2017-04-28 | A kind of full phase asynchronous oscillation method of discrimination and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107102192B (en) |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3174525B2 (en) * | 1997-03-07 | 2001-06-11 | 三菱電機株式会社 | Modeling method, prediction method, and system stabilization control method |
| JPH10271686A (en) * | 1997-03-25 | 1998-10-09 | Tokyo Electric Power Co Inc:The | Stabilizer of power system |
| JP3737640B2 (en) * | 1998-11-06 | 2006-01-18 | 株式会社東芝 | Power fluctuation detection device and computer-readable storage medium |
| CN102200564B (en) * | 2011-03-10 | 2013-01-16 | 北京四方继保自动化股份有限公司 | Power system oscillation identification method based on power angle calculation |
| CN103116106B (en) * | 2013-03-04 | 2015-05-20 | 中国南方电网有限责任公司 | Method for distinguishing free oscillation and forced oscillation of electric power system |
| CN103545782B (en) * | 2013-10-18 | 2016-05-25 | 国家电网公司 | A kind of distance protection setting method of out-of-step blocking |
| CN104934930B (en) * | 2014-03-17 | 2018-05-29 | 国家电网公司 | Unbalanced fault differential protection accelerated method in a kind of vibration |
| CN104135017B (en) * | 2014-07-23 | 2016-04-20 | 华北电力大学 | A kind of Out-of-Step Splitting Systems method of discrimination based on oscillation energy |
| CN104184157B (en) * | 2014-08-01 | 2017-02-01 | 四川大学 | On-line low-frequency oscillation rapid determination method based on waveform tracking |
| CN106300255B (en) * | 2015-06-09 | 2019-05-21 | 中国电力科学研究院 | A kind of wide area standby Out-of-Step Splitting Systems judgment method based on asynchronous oscillation characteristic set |
| CN105552881B (en) * | 2015-12-08 | 2017-10-20 | 东北电力大学 | A kind of AC system multi-frequency oscillation based on wide area measurement information is combined Out-of-Step Splitting Systems criterion method |
-
2017
- 2017-04-28 CN CN201710296997.3A patent/CN107102192B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN107102192A (en) | 2017-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2636977C (en) | Improvements in or relating to current differential protection relays | |
| CN101542662B (en) | A method and an apparatus for predicting the future behavior of currents in current paths | |
| KR101129634B1 (en) | Method and device for reclosing control using a harmonic ratio | |
| WO2006039233A2 (en) | Systems and methods for protection of electrical networks | |
| CN104201645B (en) | A kind of abnormal differential protecting method several greatly of anti-sampled value | |
| CN103746352B (en) | A kind of route protection phase-selecting method not affected by the method for operation | |
| CN106329474B (en) | Protection device and method of operating the same, computer program product and electrical installation | |
| EP3131197B1 (en) | Induction motor long start protection | |
| CN103780176A (en) | Low-excitation limit and field loss protection coordination method | |
| CN103730906A (en) | Method for coordination control over restraint in mixed direct-current transmission phase-commutation failure | |
| US20140118864A1 (en) | Method and system for power swing detection in a generator | |
| WO2018023909A1 (en) | Voltage integral-based method for determining saturation of transformer core | |
| EP3850379A1 (en) | Distance protection of electric power delivery systems using time domain and frequency domain | |
| WO2012065666A1 (en) | A method for protecting a synchronous machine against damage caused by pole slipping | |
| CN107102192B (en) | A kind of full phase asynchronous oscillation method of discrimination and device | |
| CN108493903B (en) | Voltage-free energy-pumping reactor differential protection method and device | |
| CN112564065B (en) | Pseudo-synchronous differential protection method and system for direct-current transmission line | |
| CN210273474U (en) | High-low voltage electrified automatic switching-on protection device | |
| CN110492444B (en) | Transformer substation bus differential protection method and device | |
| CN109613398B (en) | Fault direction discrimination method and discrimination element for high-voltage alternating current-direct current hybrid power grid | |
| CN112510650A (en) | Electric leakage protection method and device and electric leakage multi-stage protection system | |
| JP6141138B2 (en) | Power system control device and control system | |
| Cui et al. | Dynamic state estimation assisted posturing for generator out-of-step protection | |
| CN103390885A (en) | Method for enabling distance protection to enter power system oscillation interlocking logic | |
| JP2016197947A (en) | Failure detector, circuit breaker including failure detector, and system parallel off detection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190723 |