CN112491006A - Optical fiber differential protection method for cutting hot spare line fault and storage medium - Google Patents
Optical fiber differential protection method for cutting hot spare line fault and storage medium Download PDFInfo
- Publication number
- CN112491006A CN112491006A CN202011181616.5A CN202011181616A CN112491006A CN 112491006 A CN112491006 A CN 112491006A CN 202011181616 A CN202011181616 A CN 202011181616A CN 112491006 A CN112491006 A CN 112491006A
- Authority
- CN
- China
- Prior art keywords
- line
- circuit
- current
- phase
- condition
- 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.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 106
- 238000000034 method Methods 0.000 title claims abstract description 43
- 238000003860 storage Methods 0.000 title claims abstract description 9
- 238000005520 cutting process Methods 0.000 title claims abstract description 6
- 238000005070 sampling Methods 0.000 claims description 39
- 238000004422 calculation algorithm Methods 0.000 claims description 15
- 239000000835 fiber Substances 0.000 claims description 14
- 238000004364 calculation method Methods 0.000 claims description 11
- 238000004590 computer program Methods 0.000 claims description 10
- 230000004913 activation Effects 0.000 claims description 4
- 230000008569 process Effects 0.000 abstract description 6
- 230000002159 abnormal effect Effects 0.000 abstract description 5
- 230000005856 abnormality Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 11
- 230000006870 function Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 230000009699 differential effect Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/28—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus
- H02H3/30—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus using pilot wires or other signalling channel
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0061—Details of emergency protective circuit arrangements concerning transmission of signals
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses an optical fiber differential protection method and a storage medium for cutting off hot standby line faults, which are used for collecting voltage states at two sides and the opening position of a circuit breaker at the side, responding to the condition that the opening position of the circuit breaker is abnormal and judging whether to start an optical fiber differential line protection device or not according to set logic conditions. In the process of judging the fault of the hot standby line, the method carries out the judgment of the optical fiber differential protection starting by combining the starting state of the opposite side device, the voltage state of two sides, the opening position of the circuit breaker of the local side and other conditions, and accelerates the judgment process of the optical fiber differential protection starting of the hot standby line. The method can quickly and accurately judge the optical fiber differential starting state of the hot standby line, avoids the influence of the position abnormality of the hot standby line breaker on the optical fiber differential protection, and shortens the fault clearing time of the hot standby line.
Description
Technical Field
The invention belongs to the field of relay protection of power systems, and particularly relates to an optical fiber differential protection method and a storage medium for rapidly removing a hot standby line fault.
Background
The hot standby circuit refers to a circuit which has an operating condition, only one circuit breaker at one end of the circuit is disconnected, the other circuit breaker at the other end is switched on, and the circuit can be switched to operate only by carrying out one-time switching-on operation on the disconnected circuit breaker. The hot standby circuit is generally used as a power supply standby connection circuit, and the hot standby circuit is put into operation when the power supply connection circuit is abnormal.
Since optical fiber differential line protection has high reliability, rapidity, and clear protection range, it is widely used as a main protection in line protection. The optical fiber differential line protection device has an individual differential start requirement, and the requirement is that each optical fiber differential line protection device is provided with an independent current start element, differential current cannot be used as a start element of the device independently, and an alternating current voltage amount and the like can be used as an auxiliary start element when necessary. The reliability and sensitivity of the optical fiber differential protection starting element are one of the standards for examining the optical fiber differential protection.
After the hot standby line breaks down, no fault current exists at the break-off side of the breaker due to the fact that the broken breaker isolates a fault point, the voltage fluctuation is small under the normal condition, and the optical fiber differential protection starting is mainly realized by means of the breaker position auxiliary criterion. If the position of the breaker is abnormal at the moment, the optical fiber differential protection cannot be started normally, so that the optical fiber differential protection cannot timely act to remove the fault.
Disclosure of Invention
The invention aims to provide an optical fiber differential protection method for rapidly cutting off faults of a hot standby line, which is used for solving the problem that the optical fiber differential protection action speed of the hot standby line is low under the condition that a circuit breaker is abnormal in position.
In order to solve the technical problems, the invention adopts the following technical scheme.
The invention provides an optical fiber differential protection method for rapidly cutting off hot standby line faults, which comprises the following steps: the method comprises the steps that optical fiber differential circuit protection devices are arranged on two sides of a hot standby circuit, the optical fiber differential circuit protection devices on the local side collect three-phase current of the circuit, three-phase voltage of a bus connected to the local side of the circuit, phase voltage marks of each bus connected to the opposite side of the circuit and the position of a circuit breaker on the local side of the circuit according to set frequency, receive the three-phase current of the opposite side of the circuit transmitted by the optical fiber differential circuit protection devices on the opposite side of the circuit, and convert collected data into effective values; the method comprises the following steps: determining the opening position of the circuit breaker, and judging the following logic conditions based on the opening position of the circuit breaker, the three-phase current effective value of the local side of the circuit, the three-phase current effective value of the opposite side of the circuit, the voltage marks of each phase of the bus connected to the opposite side of the circuit and the three-phase voltage effective value of the bus connected to the local side of the circuit:
condition 1: starting a common condition criterion for the optical fiber differential protection of the hot standby line;
condition 2: the opening position node of the circuit breaker at the local side of the circuit is an opening position, and the optical fiber differential circuit protection device mistakenly considers that the circuit breaker is in a closing state;
condition 3: the effective value of the phase voltage of the current generation phase of the protection differential current of the current side of the circuit is smaller than the specific proportion of the rated voltage value;
the condition 4 is that the three-phase voltage effective values of the buses connected to the current side of the circuit are all larger than the specific proportion of the rated voltage value;
condition 5: the effective value of the bus phase voltage of the differential current generation phase of the opposite side protection of the circuit is smaller than the specific proportion of the rated voltage value;
condition 6: generating a specific proportion that the effective value of the bus phase voltage connected with the opposite side line protection differential current before a selected time interval is greater than the rated voltage value;
when the above conditions 1, 2 and 3 are all satisfied, the differential protection is started, the optical fiber differential circuit protection device on the side is started, and a start mark is sent to the optical fiber differential circuit protection device on the opposite side;
when the above condition 1, condition 2, condition 4, condition 5, and condition 6 are all satisfied, the present-side optical fiber differential circuit protection device is activated, and an activation flag is sent to the opposite-side optical fiber differential circuit protection device.
Further, the condition 1: the hot standby line optical fiber differential protection starting common condition criterion specifically comprises the following conditions 101, 102, 103 and 104, if the conditions 101, 102, 103 and 104 are all satisfied, the condition 1 hot standby line optical fiber differential protection starting common condition criterion is satisfied,
condition 101: the effective value of a certain phase difference current of the line is greater than the constant value of a differential action current, Idφ＞Iset，IdφFor an effective value of a phase difference current, I, of the linesetSetting the differential motion current;
condition 102: effective value I of three-phase current of the current side of the circuitφAre all less than the no-flow threshold value Iwl，Iφ＜Iwl；
Condition 103: the optical fiber channel is normal;
condition 104: the differential protection of the optical fiber at the opposite side of the circuit is started;
wherein
Is phase A, B or C, IφThe effective value of A-phase current, the effective value of B-phase current or the effective value of C-phase current of the current side of the circuit can be represented; differential current of sampling point of certain phase of line
The calculation formula of (2) is as follows:
the sampling point current of a certain phase on the local side of the circuit,
the current is generated for a sampling point of a certain phase at the opposite side of the line according to a certain phase difference of the line
And calculating the effective value I of a phase difference current of the circuit by using a full-cycle Fourier algorithmdφ。
Furthermore, if the two side optical fiber differential circuit protection devices are started and the effective value of a phase differential current of the circuit is larger than the product of the effective value of the braking current of the corresponding phase of the circuit and a set coefficient, the circuit protection device at the side emits an optical fiber differential tripping command to trip off the circuit breaker switch at the side,
differential current of sampling point of certain phase of line
The calculation formula of (2) is as follows:
the current of a sampling point of a certain phase at the side,
for the current at a sampling point of a certain phase on the opposite side, the current is differentiated according to the sampling point of the certain phase of the line
Calculating the effective value I of a certain phase difference current of the circuit by a full-cycle Fourier algorithmdφ，
Phase A, B or C;
braking current at certain phase sampling point of line
The calculation formula of (2) is as follows:
braking current according to a certain phase sampling point of a line
Calculating the effective value I of a phase braking current of the circuit by a full-cycle Fourier algorithmzφ。
Further, if the opening position of the circuit breaker at the local side of the line is judged to be normal, if the condition 1 is met, the hot standby line optical fiber differential protection starting common condition criterion is met, and the opening position node of the circuit breaker at the local side of the line is in the closed position, the optical fiber differential line protection device at the local side of the line is started, and a starting mark is sent to the optical fiber differential line protection device at the opposite side of the line.
Further, the selected time interval in condition 6 is selected to be 60 msec.
The invention further provides a computer readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the steps of the optical fiber differential protection method for clearing the hot spare line fault according to the above technical solution.
Compared with the prior art, the invention has the beneficial effects that:
1) the method eliminates the influence of the abnormal position of the hot standby circuit breaker on the starting of the differential protection, improves the sensitivity of the starting of the differential protection, and shortens the starting time and the action time of the optical fiber differential protection.
2) The method increases the judgment of the current voltage state of the buses at the two ends of the hot standby circuit and the voltage state before the selected interval time, improves the sensitivity and the reliability of the differential protection starting, and further improves the reliability of the differential protection action.
3) The method is not influenced by power systems on two sides of the line and is irrelevant to the protection fixed value of the hot standby line feeder.
Drawings
FIG. 1 is a flow chart of a method provided by an embodiment of the present invention;
fig. 2 is a schematic diagram of a conventional fiber differential between two ends of a line.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art without creative efforts based on the technical solutions of the present invention belong to the protection scope of the present invention.
In the first embodiment, fig. 2 is a schematic diagram of a conventional differential operation of two optical fibers at two ends of a line, where one end is an M side, and a circuit breaker thereof is in an on position, and the other end is an N side, and the circuit breaker thereof is in an off position. The N-side line optical fiber differential line protection device is exemplified and explained with reference to the flowchart of fig. 1, and the steps thereof are as follows:
1) the N side of the line collects three-phase voltage sampling points of buses connected with the N side of the line at constant frequency
Three-phase current sampling point
And sampling points of synchronous three-phase current (namely the line three-phase current of the opposite side (M side) of the line) transmitted by the opposite side device
2) The line N side device receives the fiber differential protection starting state B _ QD of the opposite side M side device.
3) The circuit N side device receives states B _ UA _ DOWN1, B _ UB _ DOWN1 and B _ UC _ DOWN1 that the effective value of each phase voltage of a bus connected to the current circuit M side of the opposite side M side device is smaller than 0.9 times of rated voltage.
4) The line N side device receives states B _ UA _ UP1, B _ UB _ UP1 and B _ UC _ UP1 that the effective value of the voltage value of each phase of a bus connected to the line M side is greater than 0.9 times of the rated voltage before the M side device is 60 ms.
5) The N-side line protection device calculates the differential current and the braking current of the sampling points and stores the differential current and the braking current into a corresponding sampling point array, and the records are as follows:
calculating the differential current of the line sampling point:
phi is A, B or C-phase.
Calculating the braking current of a line sampling point:
phi is A, B or C-phase.
6) And converting the sampling point data into an effective value of each phase current of the N side, an effective value of each phase voltage, an effective value of each phase differential current of the circuit and an effective value of each phase brake current of the circuit through a full-period Fourier algorithm.
The calculation formula of the full-cycle Fourier algorithm is as follows:
in the above formula, F represents the effective value, n represents the number F of sampling points of a cycle[j]Is an array of sample points.
Calculating the following effective amount of the M-side line protection device by a full-cycle Fourier algorithm:
(A) calculating the effective value I of each phase currentφ。
(B) Calculating the effective value I of each phase difference current of the linedφAnd effective value of braking current Izφ。
(C) Calculating the effective value U of each phase voltageφAnd records the effective value of the voltage.
7) The N-side device judges the state of each phase voltage of the bus at the side:
(A) and judging whether the effective value of the current voltage of each phase of the bus at the side is less than 0.9 time of the rated voltage value, if so, marking the corresponding voltage as 1, and otherwise, marking the voltage as 0. E.g. effective value U of A-phase voltageALess than 0.9 times the nominal voltage value, the B _ UA _ DOWN2 flag is 1, otherwise it is 0. The same method judges the B-phase voltage state flag B _ UB _ DOWN2 and the C-phase voltage state flag B _ UC _ DOWN 2.
(B) And judging whether the effective value of the voltage of each phase of the bus at the current side is greater than 0.9 times of rated voltage before the current side is 60ms (the 60ms is the interval set in the embodiment, and other time intervals can be set according to actual requirements in other embodiments), if so, marking the corresponding voltage as 1, otherwise, marking the voltage as 0. If the effective value of the A phase voltage is more than 0.9 times of the rated voltage value before 60ms, the B _ UA _ UP2 is marked as 1, otherwise, the A phase voltage is 0. The same method determines the B-phase voltage state flag B _ UB _ UP2 and the C-phase voltage state flag B _ UC _ UP 2.
(C) The N-side device transmits the various voltage states determined above to the M-side device through the optical fiber.
(D) The M-side device adopts the processes A to C to send the judged phase voltage states of each phase to the N-side device through the optical fiber.
8) And the N-side line device judges the state of the optical longitudinal channel, the optical fiber channel normally opens the optical fiber differential protection, and otherwise, the optical fiber differential protection is locked.
9) The differential start of the hot standby line optical fiber is determined according to the characteristics of the hot standby line, and the A-phase fault is analyzed.
(A) Common condition criterion for hot spare line
Condition 1: effective value of phase difference current I of linedφGreater than the constant value of differential motion current Iset，Idφ＞Iset；
Condition 2: local side three-phase current effective value IφAre all smaller than the no-flow threshold Iwl(which may be set at 0.04 times the rated current in a specific embodiment) as Iφ＜Iwl；
Condition 3: the optical fiber channel is normal;
condition 4: the protection of the opposite side optical fiber differential circuit protection device is started;
the specific logic is as follows:
Iφcan represent the effective value of the A-phase current, the effective value of the B-phase current or the effective value of the C-phase current;
when the four conditions are all satisfied, the common condition criterion for the differential start of the optical fiber satisfies the conditions.
Taking the phase a fault as an example, the common condition judgment logic for fiber differential start is as follows:
IAeffective value of A phase current, IBEffective value of B-phase current, ICThe effective value of the C-phase current.
(B) Logic for hot standby line when circuit breaker position node is normal
Condition 1: the common condition criterion for the differential starting of the optical fiber meets the condition;
condition 2: the opening position node of the circuit breaker at the side is in an on position;
the specific logic is as follows:
and the optical fiber differential starting common condition criterion meets the condition that the node at the opening position of the circuit breaker at the side is in the on position.
When the above conditions (i.e., the condition (B)) are satisfied, the present-side fiber differential protection is activated and immediately goes to the opposite-side fiber differential protection activation flag.
(C) Logic for open position abnormality of breaker position
Condition 1: the common condition criterion for the differential starting of the optical fiber meets the condition;
condition 2: the opening position node of the circuit breaker at the side is an opening position, and the protection device mistakenly considers that the circuit breaker is in a closing state;
condition 3: differential current of the circuit local side device generates the corresponding bus phase voltage effective value UφLess than 0.9 rated voltage value UnIs shown as Uφ＜0.9Un；
Condition 4: the three-phase voltage effective values of the bus at the side are all larger than 0.9 rated voltage value UnExpressed as: u shape3φ＞0.9Un，U3φThe effective value of the phase A voltage of the current side, the effective value of the phase B voltage of the current side or the effective value of the phase C voltage of the current side is expressed;
condition 5: the opposite line side of the corresponding line differential current generation phase is connected with the effective value U of the bus phase voltagedφLess than 0.9 rated voltage value Un(Udφ＜0.9Un)；
Condition 6: the effective value of the phase voltage of the bus connected to the opposite side of the circuit before the differential current generating phase is 60ms is more than 0.9 rated voltage value (U)dφ-3T＞0.9Un)；
The specific logic is as follows:
(1) when the above conditions 1, 2 and 3 are all satisfied, the differential protection is started, and the logic is as follows:
the common condition criterion for the differential start of the optical fiber meets the condition
&The opening position node of the circuit breaker is a branch position&(Uφ＜0.9Un)
Taking the phase a fault as an example, the differential protection enable logic under such conditions is as follows:
the common condition criterion for the differential starting of the optical fiber meets the condition that the node of the opening position of the breaker is the opening position & B _ UA _ DOWN2
(2) When the above conditions 1, 2, 4, 5 and 6 are all satisfied the differential protection is activated,
the logic is as follows:
the common condition criterion for the differential start of the optical fiber meets the condition&The opening position node of the circuit breaker is a branch position&(U3φ＞0.9Un)&(Udφ＜0.9Un)&(Udφ-3T＞0.9Un)
Taking the phase a fault as an example, the differential protection enable logic under such conditions is as follows:
the node of the common condition criterion for optical fiber differential starting and the circuit breaker opening position is the open position
&B_UA_UP2&B_UB_UP2&B_UC_UP2&B_UA_DOWN1
&B_UA_UP1
When the two starting conditions are met, the optical fiber differential protection at the side is started and the starting mark of the optical fiber differential protection at the opposite side is sent out immediately.
When the effective value of a certain phase current of the circuit is larger than the limit value of the effective value of the differential current, the differential current generated by the phase is judged.
(10) On the basis of the above embodiment, the following operation logic for optical fiber differential protection is also included
Condition 1: starting the optical fiber differential protection of the device at the side;
condition 2: starting the optical fiber differential protection of the opposite side device;
condition 3: the differential current is greater than 0.6 times the braking current;
the specific formula is as follows:
optical fiber differential protection starting of local side device and optical fiber differential protection starting of opposite side device
0.6 times of brake current & lt differential current & gt
When the above differential action conditions are met, the circuit protection device at the side sends out an optical fiber differential tripping command to trip off the circuit breaker switch at the side.
In a second embodiment, a method for protecting a differential optical fiber circuit to remove a fault of a hot standby circuit is shown in fig. 2, which is a schematic diagram of a differential optical fiber circuit at two ends of a conventional circuit, where one end is an M side and a breaker thereof is in an on position, and the other end is an N side and a breaker thereof is in an off position. The method comprises the steps that optical fiber differential circuit protection devices are arranged on two sides of a hot standby circuit, the optical fiber differential circuit protection devices on the local side acquire three-phase current of the local side (namely N side) of the circuit, three-phase voltage of a bus connected with the local side of the circuit, various marks of voltage of the bus connected with the opposite side (namely M side) of the circuit and the position of a circuit breaker on the local side of the circuit according to set frequency, receive synchronous three-phase current of the opposite side of the circuit transmitted by the optical fiber differential circuit protection devices on the opposite side of the circuit, and convert acquired data into effective values; the method further comprises the following steps: determining the opening position of the circuit breaker, and judging the following logic conditions based on the opening position of the circuit breaker, the three-phase current effective value of the local side of the circuit, the three-phase current effective value of the opposite side of the circuit, the bus voltage effective value of the local side of the circuit, the phase voltage state flags of each phase of the bus connected to the opposite side of the circuit and the three-phase voltage effective value of the bus connected to the opposite side of the circuit:
condition 1: starting a common condition criterion for the optical fiber differential protection of the hot standby line;
condition 2: the opening position node of the circuit breaker at the side is an opening position, and the optical fiber differential circuit protection device mistakenly considers that the circuit breaker is in a closing state;
condition 3: effective value U of phase voltage of local side line protection differential current generation phaseφA specific proportion smaller than the rated voltage value Un, U in the present embodimentφ＜0.9Un；
And 4, under the condition that the three-phase voltage effective values of the bus at the side are all larger than the specific proportion of the rated voltage value Un, in the embodiment, U3φ＞0.9Un，U3φCan represent the effective value of the A-phase voltage, the B-phase voltage or the C-phase voltage;
condition 5: effective phase voltage value U of the differential current generating phase of the opposite line protectiondφA specific proportion smaller than the rated voltage value Un, denoted as U in this embodimentdφ＜0.9Un；
Condition 6 effective value U of bus phase voltage of side line protection differential current generation phase before selected time intervaldφ-3TA specific proportion greater than the nominal voltage value Un, denoted U in the present embodimentdφ-3T＞0.9Un；
When the above conditions 1, 2 and 3 are all satisfied, the differential protection is started, the optical fiber differential circuit protection device on the side is started, and a start mark is sent to the optical fiber differential circuit protection device on the opposite side;
when the above condition 1, condition 2, condition 4, condition 5, and condition 6 are all satisfied, the present-side optical fiber differential circuit protection device is activated, and an activation flag is sent to the opposite-side optical fiber differential circuit protection device.
When the effective value of a certain phase current of the circuit is larger than the limit value of the effective value of the differential current, the differential current generated by the phase is judged. In this embodiment, the sampling point data is converted into an N-side effective value of each phase current, an N-side effective value of each phase voltage, an N-side effective value of each phase differential current, and an N-side effective value of each phase brake current by a full-period fourier algorithm.
The calculation formula of the full-cycle Fourier algorithm is as follows:
in the above formula, F represents the effective value, n represents the number F of sampling points of a cycle[j]Is an array of sample points.
Calculating the following effective amount of the M-side line protection device by a full-cycle Fourier algorithm:
(A) calculating the effective value I of each phase currentφ。
(B) Calculating the effective value of the differential current I of each phasedφAnd effective value of braking current Izφ。
(C) Calculating the effective value U of each phase voltageφAnd recording the effective value of the voltage。
In this embodiment, the condition 1: the hot standby line optical fiber differential protection starting common condition criterion specifically comprises the following conditions 101, 102, 103 and 104, if the conditions 101, 102, 103 and 104 are all satisfied, the condition 1 hot standby line optical fiber differential protection starting common condition criterion is satisfied,
condition 101: effective value of phase difference current I of linedφGreater than the constant value of differential motion current Iset，Idφ＞Iset；
Condition 102: three-phase current I of the local side of the circuitφAre all less than the no-flow threshold value IwlIs shown as Iφ＜Iwl，IφCan represent the effective value of the A-phase current, the effective value of the B-phase current or the effective value of the C-phase current;
condition 103: the optical fiber channel is normal;
condition 104: starting the differential protection of the opposite side optical fiber;
wherein
To phase A, B, C, the phase of the line is shifted by the sampling point current
The calculation formula of (2) is as follows:
the current of a sampling point of a certain phase at the side,
for the opposite side corresponding to the sampling point current, according to the line differential sampling point current
And calculating the effective value I of a certain phase difference current on two sides by using a full-cycle Fourier algorithmdφ。
Taking the phase-B fault as an example, the common condition judgment logic for the fiber differential start is as follows:
wherein IAEffective value of A phase current, IBEffective value of B-phase current, ICThe effective value of the C-phase current.
Third embodiment, on the basis of the second embodiment, this embodiment provides an optical fiber differential protection method for clearing a hot spare line fault, and the method further includes the following steps:
if the opening position of the circuit breaker at the side is judged to be normal, if the condition 1 is met, the hot standby circuit optical fiber differential protection starting public condition criterion is met, and the opening position node of the circuit breaker at the side is in the closed position, the optical fiber differential circuit protection device at the side is started, and a starting mark is sent to the optical fiber differential circuit protection device at the opposite side.
Fourth embodiment, on the basis of the second or third embodiment, this embodiment provides an optical fiber differential protection method for clearing a hot spare line fault, where the method further includes the following steps:
if the two side optical fiber differential circuit protection devices are started and the effective value of the local side circuit protection differential current is larger than the product of the effective value of the corresponding phase brake current of the circuit and the set coefficient, the local side circuit protection device emits an optical fiber differential tripping command to trip off the local side breaker switch.
Current at certain phase differential sampling point of line
The calculation formula of (2) is as follows:
the current of a sampling point of a certain phase at the side,
for the opposite phase corresponding to the sampling point current, according to the line differentialSample point current
Calculating the effective value I of a certain phase difference current on two sides by a full-cycle Fourier algorithmdφ；
Line brake sampling point current
The calculation formula of (2) is as follows:
according to line brake sampling point current
And calculating the effective value I of the braking current of a certain phase of the circuit by using a full-cycle Fourier algorithmzφ，
Phase A, B, C.
In the process of judging the fault of the hot standby line, the method carries out the judgment of the optical fiber differential protection starting by combining the starting state of the opposite side device, the voltage state of two sides, the opening position of the circuit breaker of the local side and other conditions, and accelerates the judgment process of the optical fiber differential protection starting of the hot standby line. The method can quickly and accurately judge the optical fiber differential starting state of the hot standby line, avoids the influence of the position abnormality of the hot standby line breaker on the optical fiber differential protection, and shortens the fault clearing time of the hot standby line.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (8)
1. A fiber differential protection method for cutting off faults of a hot standby line comprises the steps that fiber differential line protection devices are arranged on two sides of the hot standby line, and the fiber differential line protection device is characterized in that the fiber differential line protection device on the local side collects three-phase current of the line, three-phase voltage of a bus connected to the local side of the line, phase voltage state flags of each phase of the bus connected to the opposite side of the line and the position of a circuit breaker on the local side of the line according to set frequency, receives the three-phase current of the opposite side of the line transmitted by the fiber differential line protection device on the opposite side of the line, and converts collected data; the method further comprises the following steps: determining the opening position of the circuit breaker, and judging the following logic conditions based on the opening position of the circuit breaker, the three-phase current effective value of the local side of the circuit, the three-phase current effective value of the opposite side of the circuit, the phase voltage state flag of each phase of the bus connected to the opposite side of the circuit and the three-phase voltage effective value of the bus connected to the local side of the circuit:
condition 1: starting a common condition criterion for the optical fiber differential protection of the hot standby line;
condition 2: the opening position node of the circuit breaker at the local side of the circuit is an opening position, and the optical fiber differential circuit protection device mistakenly considers that the circuit breaker is in a closing state;
condition 3: the effective value of the phase voltage of the current generation phase of the protection differential current of the current side of the circuit is smaller than the specific proportion of the rated voltage value;
the condition 4 is that the three-phase voltage effective values of the buses connected to the current side of the circuit are all larger than the specific proportion of the rated voltage value;
condition 5: the effective value of the phase voltage of the differential current generation phase at the opposite side of the circuit is smaller than the specific proportion of the rated voltage value;
condition 6: generating a specific proportion that the effective value of the bus phase voltage connected with the opposite side line protection differential current before a selected time interval is greater than the rated voltage value;
when the above conditions 1, 2 and 3 are all satisfied, the differential protection is started, the optical fiber differential circuit protection device on the side is started, and a start mark is sent to the optical fiber differential circuit protection device on the opposite side;
when the above condition 1, condition 2, condition 4, condition 5, and condition 6 are all satisfied, the present-side optical fiber differential circuit protection device is activated, and an activation flag is sent to the opposite-side optical fiber differential circuit protection device.
2. The method for fiber optic differential protection for clearing hot spare line faults as claimed in claim 1, wherein said condition 1: the hot standby line optical fiber differential protection starting common condition criterion specifically comprises the following conditions 101, 102, 103 and 104, if the conditions 101, 102, 103 and 104 are all satisfied, the condition 1 hot standby line optical fiber differential protection starting common condition criterion is satisfied,
condition 101: the effective value of a certain phase differential current of the circuit is greater than the constant value of the differential motion current;
condition 102: the effective values of the three-phase currents at the current side of the circuit are all smaller than the no-current threshold value;
condition 103: the optical fiber channel is normal;
condition 104: the differential protection of the optical fiber at the opposite side of the circuit is started;
differential current of sampling point of certain phase of line
The calculation formula of (2) is as follows:
the sampling point current of a certain phase on the local side of the circuit,
for the current of the opposite side of the line corresponding to the sampling point of the phase, the differential current is obtained according to the sampling point of the phase of the line
Calculating the effective value I of a certain phase difference current of the circuit by a full-cycle Fourier algorithmdφ。
3. The method as claimed in claim 1, wherein if the fiber differential circuit protection devices on both sides of the circuit are activated and the effective value of the differential current of the circuit is greater than the product of the effective value of the braking current of the corresponding phase of the circuit and the set coefficient, the local side circuit protection device will send a fiber differential trip command to trip off the local side breaker switch,
differential current of sampling point of certain phase of line
The calculation formula of (2) is as follows:
the sampling point current of a certain phase on the local side of the circuit,
for the current of the opposite side of the line corresponding to the sampling point of the phase, the differential current is obtained according to the sampling point of the phase of the line
Calculating the effective value I of a certain phase difference current of the circuit by a full-cycle Fourier algorithmdφ；
Braking current at certain phase sampling point of line
The calculation formula of (2) is as follows:
braking current according to a certain phase sampling point of a line
Calculating the effective value I of braking current of a certain phase of the circuit by a full cycle Fourier algorithmzφ，
Phase A, B or C.
4. The differential protection method for optical fiber to clear fault of hot spare line according to claim 3, characterized in that said setting coefficient is 0.6.
5. The method as claimed in claim 1, wherein if the switch-off position of the local side breaker of the line is determined to be normal, if condition 1 is satisfied, the common condition criterion for starting the optical fiber differential protection of the hot standby line is satisfied, and the node of the switch-off position of the local side breaker of the line is in the on position, the local side optical fiber differential line protection device of the line is started, and a start flag is sent to the opposite side optical fiber differential line protection device of the line.
6. The method of claim 1 wherein the selected time interval under condition 6 is selected to be 60 milliseconds.
7. The method of claim 1, wherein the specified proportion of the rated voltage values in condition 3, condition 4, condition 5 and condition 6 is 90%.
8. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011181616.5A CN112491006B (en) | 2020-10-29 | 2020-10-29 | Optical fiber differential protection method for cutting hot spare line fault and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011181616.5A CN112491006B (en) | 2020-10-29 | 2020-10-29 | Optical fiber differential protection method for cutting hot spare line fault and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112491006A true CN112491006A (en) | 2021-03-12 |
| CN112491006B CN112491006B (en) | 2022-09-09 |
Family
ID=74927673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011181616.5A Active CN112491006B (en) | 2020-10-29 | 2020-10-29 | Optical fiber differential protection method for cutting hot spare line fault and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112491006B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114640093A (en) * | 2022-02-23 | 2022-06-17 | 北京天能继保电力科技有限公司 | Method and device for protecting broken line of distributed power transmission and distribution line |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107317313A (en) * | 2017-06-28 | 2017-11-03 | 积成软件有限公司 | A kind of protection of current comparison pilot protection starts householder method |
| CN107465253A (en) * | 2016-06-06 | 2017-12-12 | 中国电力科学研究院 | A kind of prepared auto restart method of operating for adapting to stable system acting automatically |
| CN109980612A (en) * | 2019-02-27 | 2019-07-05 | 南京国电南自电网自动化有限公司 | A kind of method that line differential protection realizes weak feedback starting using zero-sequence fault component |
| CN110783895A (en) * | 2019-08-16 | 2020-02-11 | 南京国电南自电网自动化有限公司 | Method for rapidly judging CT disconnection in optical fiber differential protection |
-
2020
- 2020-10-29 CN CN202011181616.5A patent/CN112491006B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107465253A (en) * | 2016-06-06 | 2017-12-12 | 中国电力科学研究院 | A kind of prepared auto restart method of operating for adapting to stable system acting automatically |
| CN107317313A (en) * | 2017-06-28 | 2017-11-03 | 积成软件有限公司 | A kind of protection of current comparison pilot protection starts householder method |
| CN109980612A (en) * | 2019-02-27 | 2019-07-05 | 南京国电南自电网自动化有限公司 | A kind of method that line differential protection realizes weak feedback starting using zero-sequence fault component |
| CN110783895A (en) * | 2019-08-16 | 2020-02-11 | 南京国电南自电网自动化有限公司 | Method for rapidly judging CT disconnection in optical fiber differential protection |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114640093A (en) * | 2022-02-23 | 2022-06-17 | 北京天能继保电力科技有限公司 | Method and device for protecting broken line of distributed power transmission and distribution line |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112491006B (en) | 2022-09-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2469342C1 (en) | Method and apparatus for controlling secondary circuit measuring transformer in electric power system | |
| CN111551872B (en) | An online diagnosis method for inverter open circuit fault in PMSM drive system | |
| CN106711953B (en) | Photovoltaic inverter direct-current side short-circuit protection device and protection method | |
| CN103743963A (en) | Electric power system fault diagnosis method based on electrical quantity and state quantity | |
| CN106771838B (en) | Transformer CT disconnection discrimination method and device, and differential protection method and device | |
| CN109283407B (en) | Voltage loop monitoring system based on total station data contrastive analysis | |
| CN107367669A (en) | The method that broken string transmission line of electricity is locked based on negative sequence network | |
| CN112491006B (en) | Optical fiber differential protection method for cutting hot spare line fault and storage medium | |
| CN110571769A (en) | A differential protection method and device for transmission lines | |
| CN111398860A (en) | A hybrid PMSM drive system inverter open-circuit fault online diagnosis method | |
| CN112531688A (en) | Method for automatically generating stability control strategy test case | |
| CN110108964A (en) | Electric power supervisory control object outages recorder data processing method based on Internet of Things | |
| CN107465253A (en) | A kind of prepared auto restart method of operating for adapting to stable system acting automatically | |
| CN112736867B (en) | Method and system for rapidly judging CT disconnection of line protection device | |
| CN106300284B (en) | Single point of double mothers prevent the method, apparatus of external area error false tripping exception mother/segmentation | |
| CN110783895B (en) | Method for rapidly judging CT disconnection in optical fiber differential protection | |
| CN115575769A (en) | A grid fault detection method and system based on modal domain current distribution characteristics | |
| CN104763576B (en) | A kind of pump-storage generator protection auxiliary signal anomalous discrimination and modification method | |
| CN110687443B (en) | Method and system for judging state of primary equipment | |
| CN111371076B (en) | Differential protection method and system suitable for direct-current power distribution network line | |
| CN113917279B (en) | Power distribution network fault phase distinguishing method and system and fault line distinguishing method and system | |
| CN104931848A (en) | Electric power system line fault discrimination method based on wide-area measurement information | |
| CN106199228B (en) | Judgment method and judgment system for distributed power supply island of power grid system | |
| EP2264850A2 (en) | Thermal overload relay with trip classification | |
| JP4648789B2 (en) | Isolated operation prevention system |
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 |