CN104054001A - Method for identifying fault direction without voltage measurement information and directional element thereof - Google Patents
Method for identifying fault direction without voltage measurement information and directional element thereof Download PDFInfo
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- CN104054001A CN104054001A CN201280067228.1A CN201280067228A CN104054001A CN 104054001 A CN104054001 A CN 104054001A CN 201280067228 A CN201280067228 A CN 201280067228A CN 104054001 A CN104054001 A CN 104054001A
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- 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
- H02H7/28—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 for meshed systems
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- 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
- H02H3/302—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 involving phase comparison
-
- 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
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Locating Faults (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention discloses a method for identifying the fault direction without voltage measurement information and directional element thereof, which comprises: as to any one of protections, measuring the current value of the local line; calculating the fault component current based on said current value, and further calculating the phase angle of said fault component current; obtaining the phase angles of fault component currents from at least other two lines which are connected to the same busbar with said local line; comparing the phase angle of fault component current of said local line with that of the other lines; and identifying the fault direction based on the result of the comparison. The proposed methods and directional element without voltage measurement information can be used in both distribution and transmission systems. It shall be noted that the proposed solutions can also be used for any applications which need fault direction without available voltage information.
Description
Technical field
The present invention relates to the technical field of power transmission network or power distribution network, more specifically, relate to method and the directional element thereof of in the situation that there is no voltage measurement information, determining fault direction.
Background technology
Along with increasing distributed generator (DG) is connected in power distribution network, it is very complicated that the direction of fault current becomes, and be different from the direction of the fault current in the conventional electrical distribution system that there is no DG.In some cases, do not have traditional excess current (OC) protective relay (also can directly be called " protection ") of direction judgement that false tripping can occur, this has affected reliability, stability and the security of electric system significantly.Therefore, fault direction or the directional element for definite fault direction are very important for protection and (the P & C) system of control.
In some cases, protection can directly be made up of directional element, for example directional pilot protection.In other cases, directional element can be used as important auxiliary element in protection, for example, for the directional element of overcurrent protection.
Conventionally, the differential seat angle between voltage vector and current vector is used to estimate the fault direction relevant with sensing station.Regrettably, voltage measurement information always not can be used for protection.For the circuit in power distribution network, there is no in many cases voltage sensor.Even for the circuit that has voltage sensor in power transmission network, voltage measurement information also always can not be used.For example, in the time that sensor exists fault, or the output signal of sensor is because some reasons are not normally sent to intelligent electronic device (IED).Therefore, in the situation that there is no voltage measurement information, obtain fault direction, so that protection can correct operation be very useful.
In prior art, had some relevant solutions, these solutions attempt to provide a kind of does not need voltage measurement information and the directional element of definite fault direction.
At the article (A.KF.Pradhan etc. that " use the phase tranformation in order electric current to carry out the judgement (Fault direction estimation in radial distribution system using phase change in sequence current) of fault direction in radial distribution system ", the IEEE transactions of transmitting electricity, 2007, the 22nd volume, the 4th phase, the 2065th page to the 2071st page (A.KF.Pradhan, etc., IEEE Transactions on Power Delivery, Vol.22, No.4, Pages2065-2071, 2007)), a kind of direction detection method for power distribution network that does not need voltage measurement information has been proposed.This solution is the difference of current angle between the current vector based on before fault current vector and fault.But this method in article is on the basis of this assumption: the direction of current of current through line can not change before fault; Directional element is known to this direction simultaneously.If the change of the generating of the batch (-type) of the distributed generator being connected with electrical network (DG) and direction of current is taken into account, this hypothesis is irrational in many cases, and therefore this solution is unpractical.
For head it off, P.Jena equals in IEEE PES transmission of electricity transactions (IEEE PES Transactions on Power Delivery), to have delivered for 2009 the article of a section " dynamic perfromance (Dynamic performance of Phase-Change in Current based Directional Relaying for Transmission Line) of the power transmission line directional element changing based on current phase " by name.The method proposing in article is the expanded application of the method to A.K.Pradhan proposition, extends to power transmission line from power distribution network.Similar with method before, the method being proposed by P.Jena is also the hypothesis based on such: the direction of current of directional element before to fault is known.And, need voltage parameter and its electric current before operational failure to calculate the direction of current before fault.This solution is difficult to be used to not have in the real system of voltage measurement information equally.This scheme cannot solve the problem of existence, in the situation that there is no voltage measurement information, determines fault direction.
At another prior art article " for the no-voltage directional element research (Research on directional element without voltage in distribution network protection with DG) of the distribution network protection containing distributed power source " (Jia Wei etc., protecting electrical power system and control, 2011, the 39th volume, the 2nd phase, the 94th page to 97 pages (Jia Wei, etc., Power System Protection and Control, Vol.39, No.2, Pages94-97, 2011)), a kind of fault direction detection technology that there is no information of voltage has been proposed.The amplitude of the fault component electric current of this method based on to all circuits that are connected with same bus compares and realizes, and without any need for the voltage before fault or the direction of current before fault.In theory, the method is correct.But in the time considering actual conditions, this method is to be difficult to be implemented.In fact, by the differential protection scheme of whole bus is introduced in the method to determine that fault direction is irrational.In addition, the method need to be connected to all current informations that measure of all circuits of same bus.In the method, once a branch line is added to bus or disconnects with bus, structure and the logical algorithm of all intelligent electronic devices (IED) (in the method) of the circuit being connected with same bus all need to be changed.Therefore, the method is difficult to be implemented, and is also difficult to safeguard.
In a word, comprise that the existing solution of said method can not be used for the actual solution of the fault direction detection in the unavailable situation of voltage measurement information in essence.
For these reasons, the present invention proposes method and the directional element thereof of in the situation that there is no voltage measurement information, determining fault direction.In addition the directional element that there is no voltage measurement information proposing, can be used to distribution system and transmission system.In general the solution, proposing can be used to need in the disabled situation of voltage measurement information in any application of fault direction.
Summary of the invention
For overcoming the problems referred to above, the invention provides a kind of for determine method and the directional element thereof of fault direction in the situation that there is no voltage measurement information.
According to an aspect of the present invention, provide a kind of for determine the method for fault direction in the situation that there is no voltage measurement information, having comprised: for arbitrary protection, measure the current value of local line; Calculate fault component electric current based on described current value, and the phasing degree of further calculating described fault component electric current; Obtain the phasing degree with the fault component electric current of at least two other circuits of same bus that described local line is connected to; The phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit is compared; Result is determined fault direction based on the comparison.
According to a further aspect in the invention, provide a kind of for determine the method for fault direction in the situation that there is no voltage measurement information, having comprised: for arbitrary protection, measure the current value of local line; Obtain the current value with at least two other circuits of same bus that described local line is connected to; Current value based on described local line and described other circuit calculates fault component electric current, and the phasing degree of further calculating described fault component electric current; The phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit is compared; Result is determined fault direction based on the comparison.
According to a preferred embodiment of the invention, described method also comprises: if the phasing degree of the fault component electric current of described local line and other circuit is similar each other, determine that fault betides the reverse of local protection; If some in the phasing degree of the phasing degree of the fault component electric current of local line and the fault component electric current of other circuit are similar and almost contrary with other, determine fault betide local protection oppositely; If the phasing degree of described local line is all almost contrary with the phasing degree of all other circuits, determine that fault betides the forward of local protection.
According to a preferred embodiment of the invention, described method also comprises: obtaining phasing degree poor of calculating described local line and described other circuit behind phasing degree; The difference at described phasing degree and pre-set threshold value are compared; If at least one in the difference at described phasing degree is less than pre-set threshold value, determine that fault betides the reverse of local protection; If the difference at all described phasing degree is all significantly greater than described pre-set threshold value, determine that fault betides the forward of local protection.
According to a preferred embodiment of the invention, described method also comprises: the forward that betides local protection in fault, calculate respectively the amplitude of the each fault component electric current on described local line and other circuit; The amplitude of the fault component electric current on the amplitude of the fault component electric current on described local line and described other circuit is compared; The amplitude of determining the fault component electric current on described local line is maximum; Otherwise signal or block signal give the alarm.
According to a preferred embodiment of the invention, described method is applied to the multiple power-supply systems that are connected from same bus, multiple power-supply systems, the distribution system with distributed power generation, power distribution network, power transmission network, traditional transformer station and/or the digital transformer substation being connected with different buses.
According to a preferred embodiment of the invention, described method can by process layer, wall or towards the transformer substation case (GOOSE) of general object as the means of communication in digital transformer substation.
According to a further aspect in the invention, provide the directional element of determining fault direction in the situation that there is no voltage measurement information, described directional element comprises: measurement module, and it is configured to measure the current value of local line; Computing module, it is configured to calculate fault component electric current based on described current value, and the phasing degree of further calculating described fault component electric current; Communication module, it is configured to obtain the phasing degree that is connected to the fault component electric current of at least two other circuits of same bus with described local line; Comparison module, it is configured to the phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit to compare; Determination module, it is configured to result based on the comparison and determines fault direction.
According to a further aspect in the invention, provide the directional element of determining fault direction in the situation that there is no voltage measurement information, described directional element comprises: measurement module, and it is configured to measure the current value of local line; Communication module, it is configured to obtain the current value that is connected at least two other circuits of same bus with described local line; Computing module, it is configured to calculate fault component electric current based on the current value of described local line and other circuit, and the phasing degree of further calculating described fault component electric current; Comparison module, it is configured to the phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit to compare; Determination module, it is configured to result based on the comparison and determines fault direction.
According to a preferred embodiment of the invention, described determination module is also configured to: if described local line is similar each other to the phasing degree of the fault component electric current of other circuit, determine that fault betides the reverse of local protection; If some in the phasing degree of the phasing degree of the fault component electric current of described local line and the fault component electric current of other circuit are similar and almost contrary with other, determine fault betide local protection oppositely; If the phasing degree of described local line is all almost contrary with the phasing degree of other circuit, determine that fault betides the forward of local protection.
According to a preferred embodiment of the invention, described computing module is also configured to obtaining the poor of the phasing degree of calculating behind phasing degree between described local line and described other circuit; Described comparison module is also configured to the difference at described phasing degree and pre-set threshold value to compare; Described determination module is also configured to: if at least one in the difference at described phasing degree is less than pre-set threshold value, determine that fault betides the reverse of local protection; If the difference at all described phasing degree is all significantly greater than pre-set threshold value, determine that fault betides the forward of local protection.
According to a preferred embodiment of the invention, the forward that betides local protection in fault, described computing module is also configured to calculate respectively the amplitude of the each fault component electric current on described local line and other circuit; Described comparison module is also configured to the amplitude of the fault component electric current on the amplitude of the fault component electric current on described local line and described other circuit to compare; Described determination module is also configured to determine that the amplitude of the fault component electric current on described local line is maximum; Otherwise signal or block signal give the alarm.
According to a preferred embodiment of the invention, in multiple power supplys that described directional element is applied to being connected from same bus, in multiple power supplys of being connected with different buses, have in the distribution system of distributed power generation, in power distribution network, in electric power transport network, in traditional transformer station and/or in digital transformer substation.
According to a preferred embodiment of the invention, described directional element can be realized with the means of communication in digital transformer substation by process layer, wall or the transformer substation case (GOOSE) towards general object.
According to a preferred embodiment of the invention, described directional element can be used to be configured for the directional pilot protection of power transmission network or power distribution network.
Embodiments of the invention provide in the situation that there is no voltage measurement information; for determining the method for fault direction and the directional element for definite fault direction; this makes in power distribution network or power transmission network; in the situation that there is no voltage measurement information; protection also can be based on to forward faults direction correct judgement and correctly action, this is especially even more important for the electrical network that has multi-power system or have a distributed generator.
Brief description of the drawings
Below in connection with theme of the present invention being described in detail by the preferred illustrative embodiment shown in accompanying drawing, wherein:
Fig. 1 shows the typical power distribution network with DG;
Fig. 2 shows application of the present invention, and wherein this application is in having the many power supplys power distribution network that is connected to same bus;
Fig. 3 shows further application of the invention, and wherein this application is in having the power distribution network of many power supplys;
Fig. 4 shows further application of the invention, and wherein this application is in having the power distribution network of at least one DG;
Fig. 5 shows two other application of the present invention, and wherein said two application, in electric power transport network, and are under necessary information in fault direction in the time that voltage is unavailable; Fig. 5 a and Fig. 5 b show respectively directional pilot protection and remove Blocking Differential Protection;
Fig. 6 shows further application of the invention, and wherein this application is in having the power distribution network of multiple DG;
Fig. 7 shows the schematic diagram of the fault component circuit corresponding with circuit shown in Fig. 6;
Fig. 8 shows have corresponding with circuit shown in Fig. 7 and betides the exemplary vector schematic diagram of the fault on circuit k;
Fig. 9 shows the method for determining fault direction in the situation that there is no voltage measurement information according to embodiments of the invention;
Figure 10 shows the method for determining according to another embodiment of the present invention fault direction in the situation that there is no voltage measurement information;
Figure 11 shows the method for determining according to another embodiment of the present invention fault direction in the situation that there is no voltage measurement information;
Figure 12 shows the method for determining according to another embodiment of the present invention fault direction in the situation that there is no voltage measurement information;
Figure 13 shows in fault and betides bus but not the vector plot of fault component electric current other circuit in the situation that;
Figure 14 shows according to the directional element there is no to determine under voltage condition fault direction of the present invention.
Embodiment
Below in connection with respective drawings, exemplary embodiment of the present invention is described.For reaching clear simple and clear object, in instructions, all characteristics to practical embodiments are not described.
Fig. 1 shows the typical power distribution network with DG.As shown in Figure 1, if there is no DG in network, direction of current is from left to right so; And overcurrent protection L
2at fault F
1or F
2in situation about occurring, can not measure any fault current.Therefore, overcurrent protection L
2can be due to fault F
1or F
2generation and produce false tripping.In fact, in Fig. 1, DG is connected with network, and this situation, compared with there is no the situation of DG, has obvious difference.If DG has enough large capacity, when fault betides F
1or F
2when at the place, overcurrent protection L
2can measure a sizable fault current.At this moment, if protection L
2in there is no directional element, in the time that fault current is enough large, protect L
2can there is false tripping.
Clearly, in the power distribution network with DG, for protection, directional element is essential.Consider the general case that generally there is no voltage measurement information in power distribution network, voltage cannot be used by directional element.Even having like this in the power distribution network of DG, if it has configured directional element proposed by the invention, overcurrent protection still can correct operation.
It should be noted, propose in the method that there is no under voltage measurement information state to determine fault direction, and for determining the directional element of fault direction, can be used in power distribution network and power transmission network, on especially same bus, be connected with many power supplys network, have multiple power supplys power distribution network, there is power distribution network of DG etc.No matter have or not voltage measurement information, Fig. 2 shows application of the present invention, and wherein this application is used for many power supplys of bus power distribution network.Fig. 3 shows further application of the invention, and wherein this application is for having the power distribution network of multiple power supplys.Fig. 4 shows further application of the invention, and wherein this application is in having the power distribution network of at least one DG.Fig. 5 shows another two application in power transmission network of the present invention, and wherein in the time that voltage is unavailable, fault direction is essential.For example, voltage measurement signal is not transferred into IED, and/or voltage measurement sensor is because fault has occurred some reasons.In this case, directional element provided by the invention can be used as directional pilot protection or unlocking differential protection (as Fig. 5 a and Fig. 5 b illustrate respectively).
For reaching clear simple and clear object, below by the typical case's application of the present invention in the power distribution network of describing in detail in thering is DG.
Fig. 6 shows further application of the invention, and wherein this application is in having the power distribution network of multiple DG.In Fig. 6, this power distribution network module has n bar circuit, and every circuit is all protected (L with one
1, L
kl
n) be in series.Multiple DG are connected with many corresponding line respectively.Fault F betides on circuit k.
Fig. 7 shows the schematic diagram of the fault component circuit corresponding with circuit shown in Fig. 6.In Fig. 7, fault component circuit shows fault and betides the situation on circuit k.Can by as follows come the fault component electric current on every circuit in computational grid:
Z'
S1＝Z
1//Z
2...//Z
n(n≠k,S1) (2)
Z'
n1＝Z
1//Z
2...//Z
n(n≠k,n1) (4)
Wherein,
it is the electric current on the circuit from generator to bus; Z
sit is the equiva lent impedance of the circuit from generator to bus; Z'
s1the equiva lent impedance except all parallel lines beyond the circuit from generator to bus and faulty line k, and
it is the electric current breaking down on the circuit k of F;
it is the electric current on circuit n; Z
nit is the equiva lent impedance of circuit n; Z'
n1the equiva lent impedance except other parallel lines beyond the circuit from generator to bus and circuit n, and
Conventionally, equation (1) is similar (approximately 70 °～85 °) with the phasing degree of all resistance in equation (3), and this represents the fault component electric current on faulty line k
phasing degree and all non-fault lines on fault component electric current
phasing degree be diverse (direction is almost contrary).
Fig. 8 shows corresponding with circuit shown in Fig. 7, and the vectorial schematic diagram of fault has occurred on circuit k.
The present invention relates in the situation that there is no voltage measurement information, the solution of detection failure direction, the wherein phasing degree of fault component electric current is different between faulty line and non-fault line.As shown in Figure 8, be apparent that for a person skilled in the art the phasing degree of the fault component electric current on faulty line is almost contrary with the phasing degree of the fault component electric current on all non-fault lines.If one the phasing degree of circuit and the phasing degree of all other circuits are completely different, it is regarded as faulty line, and its fault direction is considered to forward (forward direction) (fault is positioned at the forward of relevant protection).
Fig. 9 shows the method for determining fault direction in the situation that there is no voltage measurement information according to embodiments of the invention.
As shown in Figure 9, in the situation that there is no voltage measurement information, the method for definite fault direction comprises:
Step 902, for arbitrary protection, measures the current value of local line., the protection on every circuit is configured to measure this vagabond current of its local line.
Step 904, calculates fault component electric current based on described current value, and the phasing degree of further calculating described fault component electric current.The phasing degree of the fault component electric current on each local protection calculation local line.
Step 906, obtains the phasing degree that is connected to the fault component electric current of at least two other circuits of same bus with described local line.Each local protection communicates with at least two other protections, and obtain and the circuit of same bus that its local line is connected on the phasing degree of fault component electric current.
Step 908, by the phasing degree of the fault component electric current of described local line, compares with the phasing degree of the fault component electric current of other circuit.
Step 910, result is determined fault direction based on the comparison.
Those skilled in the art can find out than existing directional element, and described solution does not need voltage measurement information to determine fault direction.In addition, propose than A.K.Pradhan and P.Jena method, described solution is determined fault direction without any need for the direction of current before fault or the information of voltage before fault.Therefore, described method and directional element thereof are for determine fault direction in the situation that there is no voltage measurement information, actual and more valuable.
In an embodiment of the present invention, if local line is similar each other to the phasing degree of the fault component electric current of other circuit, each local protection can determine that fault betides the reverse of local protection; If some in the phasing degree of the phasing degree of the fault component electric current of local line and the fault component electric current of other circuit are similar and almost contrary with other, determine fault betide local protection oppositely; If the phasing degree of local line is all almost contrary with the phasing degree of all other circuits, determine that fault betides the forward of local protection.
For arbitrary concrete protection; described solution only needs at least three current measurement information (as to have the electric current on the local line of concrete protection; and be connected to the electric current at least two other circuits of same bus with described local line) detect and the fault direction of definite circuit; and in the prior art; especially in the solution of Jia Wei; for determining fault direction, need to be connected to the current measurement information of all circuits of same bus.In addition, solution of the present invention has been simplified the demand to hardware, software and system maintenance.
Figure 10 shows the method for determining according to another embodiment of the present invention fault direction in the situation that there is no voltage measurement information.
As shown in figure 10, in the situation that there is no voltage measurement information, the method for definite fault direction comprises: step 1002 is to 1014; Wherein step 1002 to 1006 with Fig. 9 in step 902 to 906 same or similar.For making instructions succinct, same or analogous step is no longer repeated.
Step 1008, after obtaining the step at phasing degree, calculates the poor of phasing degree between described local line and other circuit;
Step 1010, compares the difference at described phasing degree and pre-set threshold value.If the difference at phasing degree is less than pre-set threshold value described at least one, go to step 1012; Otherwise, go to step 1014.
Step 1012, determines that fault betides the reverse of local protection.
Step 1014, determines that fault betides the forward of local protection.If the difference at all phasing degree is all significantly greater than described pre-set threshold value, fault betides the forward of local protection.
For example, threshold values can be preset as to 40 degree and 40 degree left and right.If the difference at least one phasing degree is less than 40 degree, local protection can determine that fault betides oppositely (representing that fault is not at the forward of local line).Even if therefore the electric current in overcurrent protection is greater than setting value, local protection does not also respond fault.That is to say, if difference is less than specific threshold, we can say that these phasing degree are mutually the same.Otherwise if all differences are all greater than 40 degree, fault betides the forward of local protection.Therefore,, if electric current is greater than setting value simultaneously, protection meeting responds fault.It should be noted that those skilled in the art can be according to being specifically used for selecting and adjusting pre-set threshold value; 40 degree are exemplary pre-set threshold value, and are not used in restriction pre-set threshold value.
In the time that fault betides faulty line, other non-fault line and faulty line are connected to same bus.As shown in Figure 8, be apparent that for a person skilled in the art the amplitude of the fault component electric current on faulty line is different from the amplitude of the fault component electric current on all other non-fault lines; In addition, in the fault component electric current on all circuits that are connected to same bus, the amplitude maximum of the fault component electric current breaking down.Therefore, difference in magnitude also can be used as strengthening auxiliary criteria and the algorithm of this solution reliability.
According to another embodiment of the present invention, in order again to check the accuracy of determining fault direction, the invention provides the other method of determining fault direction in the situation that there is no voltage measurement information.Determining that fault betides astern (for example, the embodiment shown in Fig. 9 or Figure 10) of local protection, described method also comprises the process again checking:
Steps A 01, calculates respectively the amplitude of the each fault component electric current on described local line and other circuit.For example, in the situation that fault betides forward, before local protection calculation, be used to determine that fault betides the amplitude of each fault component electric current of forward.
Steps A 02, compares the amplitude of the fault component electric current on described local line with the amplitude of the fault component electric current on other circuit.
Steps A 03, determines that the amplitude of the fault component electric current on local line is maximum.Then can reaffirm that fault betides the forward of local protection.Otherwise system exists mistake, may be garble, measuring error or current transformer mistake etc.; Then local give the alarm signal or the block signal protected.
It should be noted that described further step " amplitude of more all fault component electric currents, and the circuit of definite fault component current amplitude maximum is faulty line (phasing degree of fault component electric current is almost contrary with the phasing degree of the fault component electric current of other circuit on described faulty line) " is used as the final householder method of confirming.This householder method based on amplitude be conducive to strengthen propose in the reliability that there is no under voltage measurement information state the method for determining fault direction.But this householder method is not essential in theory.The step that what those skilled in the art can understand is based on phasing degree (for example, " determine that one of phasing degree is almost contrary with other phasing degree ", or " difference of determining phasing degree is significantly greater than described pre-set threshold value ") the respective phase angle that can determine fault component electric current is from faulty line.Even without householder method, the method also can be determined fault direction completely in the situation that there is no voltage measurement information.
Figure 11 shows according to another embodiment of the present invention for determine the method for fault direction in the situation that there is no voltage measurement information.
As shown in figure 11, in the situation that there is no voltage measurement information, the method for definite fault direction comprises: step 1102 is to 1110; Wherein step 1102,1108 and 1110 and Fig. 9 shown in step 902,908 and 910 same or similar.For making instructions succinct, same or analogous step is no longer repeated.
Step 1104, obtains the current value that is connected at least two other circuits of same bus with described local line.At each protection after the current value on its local line, the current value of other circuit can be directly measured in arbitrary local protection, for example, be connected at least two other circuits of same bus with its local line.
Step 1106, the current value based on local line and other circuit calculates fault component electric current, and the phasing degree of further calculating described fault component electric current.
In an embodiment of the present invention, if local line is similar each other to the phasing degree of the fault component electric current of other circuit, local protection can determine that fault betides the reverse of local protection; If some in the phasing degree of the phasing degree of the fault component electric current of local line and the fault component electric current of other circuit are similar and almost contrary with other, determine fault betide local protection oppositely; If the phasing degree of local line is all almost contrary with the phasing degree of the fault component electric current of all other circuits, determine that fault betides the forward of local protection.
Figure 12 shows according to another embodiment of the present invention for determine the method for fault direction in the situation that there is no voltage measurement information.
As shown in figure 12, in the situation that there is no voltage measurement information, the method for definite fault direction comprises: step 1202 is to 1214; Wherein
Step 1204 and 1206 and Figure 11 in corresponding step 1104 and 1106 same or similar, and step 1202,1208 to 1214 with Figure 10 in corresponding step 1002,1008 to 1014 same or similar.For making instructions succinct, same or analogous step is no longer repeated.
According to another embodiment of the present invention, determining that according to the embodiment shown in for example Figure 11 or Figure 12 fault betides local protection astern, shown in method also comprise the process again checking:
Steps A 01, calculates respectively the amplitude of the each fault component electric current on described local line and other circuit.For example, in the situation that fault betides forward, before local protection calculation, be used to determine that fault betides the amplitude of each fault component electric current of forward.
Steps A 02, compares the amplitude of the fault component electric current on described local line with the amplitude of the fault component electric current on other circuit.
Steps A 03, determines that the amplitude of the fault component electric current on local line is maximum.Then can reaffirm that fault betides the forward of local protection.Otherwise, there is mistake, may be garble or measuring error etc.; Then local give the alarm signal or the block signal protected.
According to embodiments of the invention, in the multiple power supplys that are connected in multiple power supplys that said method is applied to being connected from same bus, with different buses, have in the distribution system of distributed power generation, in power distribution network, in electric power transport network, in traditional transformer station and/or in digital transformer substation.
According to embodiments of the invention, said method can be realized with the means of communication in digital transformer substation by process layer, wall or the transformer substation case (GOOSE) towards general object.In particular, directly obtaining the digital transformer substation that the described method of at least two other line electricity flow valuves is easy to by having IEC61850-9-2 standard realizes.
Figure 13 shows in fault and results from bus but not the vector of fault component electric current other circuit in the situation that.
As shown in figure 13, when fault betides bus, the phasing degree of all circuits that is connected to this same bus is similar each other.Feature shown in Figure 13 shows that method provided by the present invention is not betided the impact of the fault on bus.The direction that the fault that, method proposed by the invention can be utilized phasing degree directly to determine to betide on faulty line and fault occur.And in the situation that bus breaks down, the method proposing is come (in the situation that there is no voltage measurement information) without any need for additional logic and is determined fault direction.On the contrary, in the scheme being proposed by Jia Wei in the prior art, whole bus protection is embedded in directional element to solve the fault on bus.
Figure 14 shows the directional element for definite fault direction in the situation that there is no information of voltage according to the embodiment of the present invention.
As shown in figure 14, directional element 1400 comprises measurement module 1402, computing module 1404, communication module 1406, comparison module 1408 and determination module 1410.
According to a preferred embodiment of the invention, measurement module 1402 is configured to measure the current value of local line; Computing module 1404 is configured to calculate fault component electric current based on described current value, and the phasing degree of further calculating described fault component electric current; Communication module 1406 is configured to obtain the phasing degree that is connected to the fault component electric current of at least two other circuits of same bus with described local line; Comparison module 1408 is configured to the phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and other circuit to compare; Determination module 1410 is configured to result based on the comparison and determines fault direction.
Compared with prior art, scheme proposed by the invention is actual and be easier to execution, especially in the time of the number of, lines in power distribution network/power transmission network and state variable.According to the present invention, if more circuit is connected to bus, the structure in existing protection and embedded algorithm logic do not need to carry out any amendment.And in the scheme of Jia Wei, need in this case to change setting and the algorithm logic of all protections.
According to another preferred embodiment of the invention, communication module 1406 is configured to obtain the current value that is connected at least two other circuits of same bus with described local line; Computing module 1404 is configured to calculate fault component electric current based on the current value on described local line and other circuit, and the phasing degree of further calculating described fault component electric current.
According to another preferred embodiment of the invention, determination module 1410 is also configured to: if the phasing degree of the fault component electric current of described local line and other circuit is similar each other, determine that fault betides the reverse of local protection; If some in the phasing degree of the phasing degree of the fault component electric current of described local line and the fault component electric current of other circuit are similar and almost contrary with other, determine fault betide local protection oppositely; If the phasing degree of described local line is all almost contrary with the phasing degree of all other circuits, determine that fault betides the forward of local protection.
According to another preferred embodiment of the invention, computing module 1404 is also configured to calculate the poor of phasing degree between local line and other circuit after the phasing degree that obtains described local line and other circuit; Comparison module 1408 is also configured to the difference at described phasing degree and pre-set threshold value to compare; Determination module 1410 is also configured to: if at least one in the difference at described phasing degree is less than pre-set threshold value, determine that fault betides the reverse of local protection; If the difference at all phasing degree is all significantly greater than described pre-set threshold value, determine that fault betides the forward of local protection.
According to another preferred embodiment of the invention, the forward that betides local protection in fault, computing module 1404 is also configured to calculate respectively the amplitude of the each fault component electric current on described local line and other circuit; Comparison module 1408 is also configured to the amplitude of the fault component electric current on the amplitude of the fault component electric current on described local line and other circuit to compare; Determination module 1410 is also configured to determine that the amplitude of the fault component electric current on described local line is maximum; Otherwise signal or block signal give the alarm.
In the preferred embodiment of the invention described above, in the multiple power supplys that are connected in multiple power supplys that directional element is applied to being connected from same bus, with different buses, have in the distribution system of distributed power generation, in power distribution network, in power transmission network, in traditional transformer station and/or in digital transformer substation.In addition, directional element can be realized with the means of communication in digital transformer substation by process layer, wall or the transformer substation case (GOOSE) towards general object.
According to a preferred embodiment of the invention, described directional element can be used to form the directional pilot protection for power transmission network or power distribution network.
Compared with prior art, scheme proposed by the invention actual and be easier to carry out.With reference to the description to exemplary embodiment, those skilled in the art can realize advantage of the present invention:
1, according to proposed by the invention in the situation that there is no voltage measurement information for determining method and the directional element thereof of fault direction, compared with existing directional element, this programme does not need voltage measurement information to determine fault direction.
2, according to proposed by the invention in the situation that there is no voltage measurement information for determining method and the directional element thereof of fault direction, compare with the method that A.K.Pradhan proposes with P.Jena, this programme is determined fault direction without any need for the direction of current before fault or the information of voltage before fault.Therefore, the method and directional element thereof are actual and more valuable concerning determine fault direction in the situation that there is no voltage measurement information.
3, according to proposed by the invention in the situation that there is no voltage measurement information for determining method and the directional element thereof of fault direction; for arbitrary concrete protection; this solution only needs at least three current measurement information (as have the electric current on the circuit of protection, and be connected to the electric current at least two other circuits of same bus) to detect and determine the fault direction of the circuit with this protection equipment.And in the prior art, especially, in the solution of Jia Wei, for determining fault direction, need to be connected to the current measurement information of all circuits of same bus.In addition, solution of the present invention has been simplified the demand to hardware, software and system maintenance.
4, according to proposed by the invention in the situation that there is no voltage measurement information for determining method and the directional element thereof of fault direction, scheme proposed by the invention is actual and be easier to execution, especially in the time of the number of, lines in power distribution network/power transmission network and state variable.According to the present invention, if more circuit is connected to bus, all structures in existing protection and embedded algorithm logic do not need to carry out any amendment.And in the scheme of Jia Wei, need in this case to change setting and the algorithm logic of all protections.
5, according to proposed by the invention in the situation that there is no voltage measurement information for determining method and the directional element thereof of fault direction; unlike the solution of Jia Wei, bus differential protecting need to be integrated in directional element, this has simplified the realization of solution of the present invention equally.
6, according to proposed by the invention in the situation that there is no voltage measurement information for determining method and the directional element thereof of fault direction, the saturated of current transformer (CT) produces less impact (with it on compared with the impact of current amplitude) to current phase conventionally.,, once it is saturated that CT occurs, solution provided by the present invention is more reliable than the disclosed scheme of Jia Wei.
Although invention has been described based on preferred embodiment, what it will be understood by those skilled in the art that is that these embodiment never should limit the field of the invention.Any conversion body of embodiment and amendment body all within the scope of those skilled in the art's understanding, and in the scope of the present invention limiting in the claim of enclosing, and can not depart from spirit of the present invention and thought.
Claims (15)
1. for determine the method for fault direction in the situation that there is no voltage measurement information, wherein said method comprises: for arbitrary protection,
Measure the current value of local line;
Calculate fault component electric current based on described current value, and the phasing degree of further calculating described fault component electric current;
Obtain the phasing degree with the fault component electric current of at least two other circuits of same bus that described local line is connected to;
The phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit is compared; And
Determine fault direction based on described comparative result.
2. for determine the method for fault direction in the situation that there is no voltage measurement information, wherein said method comprises: for arbitrary protection,
Measure the current value of local line;
Obtain the current value with at least two other circuits of same bus that described local line is connected to;
Current value based on described local line and described other circuit calculates fault component electric current, and the phasing degree of further calculating described fault component electric current;
The phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit is compared; And
Determine fault direction based on described comparative result.
3. method according to claim 1 and 2, wherein said method also comprises:
If the phasing degree of the fault component electric current of described local line and described other circuit is similar each other, determine that fault betides the reverse of described local protection;
If some in the phasing degree of the phasing degree of the fault component electric current of described local line and the fault component electric current of described other circuit are similar and almost contrary with other, determine fault betide described local protection oppositely;
And
If the phasing degree of described local line is all almost contrary with all phasing degree of described other circuit, determine that fault betides the forward of described local protection.
4. method according to claim 1 and 2, wherein said method also comprises:
Obtaining behind described phasing degree, calculating the poor of phasing degree between described local line and described other circuit;
The difference at described phasing degree and pre-set threshold value are compared;
If at least one in the difference at described phasing degree is less than described pre-set threshold value, determine that fault betides the reverse of described local protection; And
If the difference at all described phasing degree is all significantly greater than described pre-set threshold value, determine that fault betides the forward of described local protection.
5. according to the method described in above-mentioned arbitrary claim, wherein said method also comprises: the forward that betides described local protection in fault,
Calculate respectively the amplitude of the each fault component electric current on described local line and described other circuit;
The amplitude of the fault component electric current on the amplitude of the fault component electric current on described local line and described other circuit is compared; And
The amplitude of determining the fault component electric current on described local line is maximum; Otherwise signal or block signal give the alarm.
6. according to the method described in above-mentioned arbitrary claim, wherein said method is applied to the multiple power supplys that are connected from described same bus, multiple power supplys, the distribution system with distributed power generation, power distribution network, electric power transport network, traditional transformer station and/or the digital transformer substation being connected with different buses.
7. according to the method described in above-mentioned arbitrary claim, wherein said method can realize with the communication mode in digital transformer substation by process layer, wall or the transformer substation case towards general object.
8. for determine the directional element of fault direction in the situation that there is no voltage measurement information, wherein said directional element comprises:
Measurement module, it is configured to measure the current value of described local line;
Computing module, it is configured to calculate described fault component electric current based on described current value, and the phasing degree of further calculating described fault component electric current;
Communication module, it is configured to obtain the phasing degree with the fault component electric current of at least two other circuits of same bus that described local line is connected to;
Comparison module, it is configured to the phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit to compare;
Determination module, it is configured to determine described fault direction based on described comparative result.
9. for determine the directional element of fault direction in the situation that there is no voltage measurement information, wherein said directional element comprises:
Measurement module, it is configured to measure the current value of described local line;
Communication module, it is configured to obtain the current value that is connected at least two other circuits of same bus with described local line;
Computing module, it is configured to calculate fault component electric current based on the current value of described local line and described other circuit, and the phasing degree of further calculating described fault component electric current;
Comparison module, it is configured to the phasing degree of the fault component electric current of the phasing degree of the fault component electric current of described local line and described other circuit to compare;
Determination module, it is configured to determine fault direction based on described comparative result.
10. directional element according to claim 8 or claim 9, wherein said determination module is also configured to:
If described local line is similar each other to the phasing degree of the fault component electric current of other circuit, determine that fault betides the reverse of described local protection;
If some in the phasing degree of the phasing degree of the fault component electric current of described local line and the fault component electric current of described other circuit are similar and almost contrary with other, determine fault betide described local protection oppositely;
If the phasing degree of described local line is all almost contrary with the phasing degree of other circuit, determine that fault betides the forward of described local protection.
11. directional elements according to claim 8 or claim 9, wherein
Described computing module is also configured to obtaining the poor of the phasing degree of calculating behind described phasing degree between described local line and described other circuit;
Described comparison module is also configured to the difference at described phasing degree and pre-set threshold value to compare;
Described determination module is also configured to: if at least one in the difference at described phasing degree is less than described pre-set threshold value, determine that fault betides the reverse of described local protection; If the difference at all described phasing degree is all significantly greater than described pre-set threshold value, determine that fault betides the forward of described local protection.
12. according to the directional element described in above-mentioned arbitrary claim, the forward that wherein betides described local protection in fault,
Described computing module is also configured to calculate respectively the amplitude of the each fault component electric current on described local line and described other circuit;
Described comparison module is also configured to the amplitude of the fault component electric current on the amplitude of the fault component electric current on described local line and described other circuit to compare;
Described determination module is also configured to determine that the amplitude of the fault component electric current on described local line is maximum; Otherwise signal or block signal give the alarm.
Directional element in 13. according to Claim 8 to 12 described in any one claim, in the multiple power supplys that are connected in multiple power supplys that wherein said directional element can be applied to being connected from described same bus, with described different buses, have in the distribution system of distributed power generation, in distribution network, in power transmission network, in traditional transformer station and/or in digital transformer substation.
Directional element in 14. according to Claim 8 to 12 described in any one claim, wherein said directional element can be realized with the means of communication in digital transformer substation by process layer, wall or the transformer substation case towards general object.
Directional element in 15. according to Claim 8 to 12 described in any one claim, wherein said directional element can be used to the directional pilot protection in power transmission network or power distribution network.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| PCT/CN2012/070424 WO2013106985A1 (en) | 2012-01-16 | 2012-01-16 | Method for identifying fault direction without voltage measurement information and directional element thereof |
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| CN104054001A true CN104054001A (en) | 2014-09-17 |
| CN104054001B CN104054001B (en) | 2016-10-26 |
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| CN (1) | CN104054001B (en) |
| IN (1) | IN2014CN04230A (en) |
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| IN2014CN04230A (en) | 2015-07-17 |
| CN104054001B (en) | 2016-10-26 |
| WO2013106985A1 (en) | 2013-07-25 |
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