CN114123136A - Protection method for power distribution network under distributed energy condition - Google Patents
Protection method for power distribution network under distributed energy condition Download PDFInfo
- Publication number
- CN114123136A CN114123136A CN202111443220.8A CN202111443220A CN114123136A CN 114123136 A CN114123136 A CN 114123136A CN 202111443220 A CN202111443220 A CN 202111443220A CN 114123136 A CN114123136 A CN 114123136A
- Authority
- CN
- China
- Prior art keywords
- fault
- distributed energy
- current
- distribution network
- power distribution
- 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
- 238000000034 method Methods 0.000 title claims abstract description 25
- 230000001052 transient effect Effects 0.000 claims abstract description 13
- 239000011159 matrix material Substances 0.000 claims description 19
- 230000001133 acceleration Effects 0.000 claims description 13
- 238000011144 upstream manufacturing Methods 0.000 claims description 10
- 238000001514 detection method Methods 0.000 claims description 6
- 230000007423 decrease Effects 0.000 claims description 5
- 230000001360 synchronised effect Effects 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 9
- 238000005259 measurement Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 238000010891 electric arc Methods 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 101100499229 Mus musculus Dhrsx gene Proteins 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 238000010200 validation analysis Methods 0.000 description 1
Images
Classifications
-
- 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
-
- 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
- H02H3/02—Details
- H02H3/06—Details with automatic reconnection
- H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/40—Synchronising a generator for connection to a network or to another generator
- H02J3/42—Synchronising a generator for connection to a network or to another generator with automatic parallel connection when synchronisation is achieved
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a protection method of a power distribution network under the condition of distributed energy resources, which comprises the following steps: s1, positioning the fault position, and controlling the breaker to act to isolate the fault area; detecting the voltage of a distributed energy grid-connected point in real time, and immediately disconnecting the distributed energy from the power distribution network once the voltage drop of the distributed energy grid-connected point caused by the fault in the power distribution network is detected; s2, after time delay, a feeder line where the fault area is located is superposed, the fault area is accessed, if the fault is transient, the access state is kept, and if the fault still exists, the fault area is isolated and disconnected again; and S3, detecting the electrical state of the grid-connected point of the distributed energy, accessing the distributed energy to the power distribution network if the grid-connected point of the distributed energy is normal, and otherwise, keeping the off-grid state of the distributed energy. The scheme can avoid the problems of reclosing failure, non-synchronous closing and fault seriation, and is suitable for the power distribution network with distributed energy.
Description
Technical Field
The invention relates to the field of detection and control of a power distribution network, in particular to a protection method of the power distribution network under the condition of distributed energy.
Background
The intelligent distribution network facing energy interconnection increases a distributed renewable energy power generation mode mainly comprising photovoltaic power stations, so that the distribution network is greatly changed from a passive network to an active distribution system. Meanwhile, the energy supply is ensured to be safe and stable while the energy is clean by scientifically proportioning the energy structures and utilizing the complementary characteristics of the space-time distribution and the dynamic characteristics of the distributed energy.
For a power distribution network containing distributed energy (DG), the DG cannot be isolated in time by adopting a traditional reclosing method, the situation that the reclosing fails because an electric arc at a fault point cannot be naturally extinguished easily occurs, and as the DG is in an island operation state during the reclosing period, the risk of non-synchronous reclosing exists, and transient faults may be converted into permanent faults.
Disclosure of Invention
The invention mainly solves the technical problems that the traditional reclosing protection method in the prior art brings risks and can change transient faults into permanent faults, and provides the protection method for the power distribution network under the distributed energy condition, which can not cause reclosing failure or asynchronous reclosing due to the fact that electric arcs cannot be naturally extinguished and can avoid aggravating the fault degree.
The invention mainly solves the technical problems through the following technical scheme: a protection method of a power distribution network under the condition of distributed energy sources is characterized in that a plurality of circuit breakers are arranged in the power distribution network, the distributed energy sources are connected with the power distribution network through the circuit breakers, a current measuring device is arranged at the position of each circuit breaker, and an acceleration protection device before reclosing is installed on the outlet side of a circuit, and specifically comprises the following steps:
s1, fault detection: positioning the fault occurrence position, and controlling the action of a breaker to isolate the fault area; detecting the voltage of a distributed energy grid-connected point in real time, and immediately disconnecting the distributed energy from the power distribution network once the voltage drop of the distributed energy grid-connected point caused by the fault in the power distribution network is detected;
s2, reclosing action: after the first time delay, the feeder line where the fault area is located is superposed, the fault area is accessed, if the fault is transient, the access state is kept, and if the fault still exists, the fault area is isolated and disconnected again;
s3, detecting the state of the point-to-point: and detecting the electrical state of the grid-connected point of the distributed energy sources after a second delay, accessing the distributed energy sources to the power distribution network if the grid-connected point of the distributed energy sources is recovered to be normal, and otherwise, keeping the off-grid state of the distributed energy sources.
Preferably, the fault location method is as follows:
the distribution network region that encloses each circuit breaker is regarded as the unit protection area, no longer contains the circuit breaker in the unit protection area, the circuit breaker is as the connecting channel between two unit protection areas, for the regional serial number of setting for each unit protection, it is regional current reference positive direction to get the current direction by the regional flow of little serial number to the regional big serial number, it is regional for the upstream of circuit breaker that the regional one side of little serial number that the circuit breaker is connected is defined, the big serial number one side that the circuit breaker is connected is regional for the downstream of circuit breaker, the fault judgement basis is as follows:
Eij＝cijDF·j
DF·j＝[D1,D2,…,Dj]T
in the formula, cijFor the elements of the associative matrix, EijFor circuit breaker BjIn the direction of the current fault component, if E ij1, the current fault component is determined by the circuit breaker BjFlow direction area Ai(ii) a If EijIf-1, the current fault component is represented by region aiFlow direction breaker Bj；DF·jAs a fault information matrix, D1Direction of current fault component of 1 st circuit breaker, D2To DjAnd so on.
Preferably, the incidence matrix elements are determined by:
Aiis the ith area, BjIs the jth breaker.
Preferably, the fault information matrix is determined by:
if the fault occurs before, the breaker B1When the current is positive, and the current direction is unchanged and the amplitude is increased after the fault occurs, D1Is 1; when the current direction is unchanged and the amplitude decreases or the direction changes, D1Is-1; if the current at the breaker is in the negative direction before the fault occurs, D is determined when the current direction is unchanged and the amplitude is increased after the fault occurs1Is-1; when the current direction is unchanged and the amplitude decreases or the direction changes, D1Is 1; d2To DjDetermined in the same way.
Preferably, the distributed energy source is an inverter distributed energy source under a PQ control mode, a current limiter is added in an inverter loop, and the short-circuit current is limited within 2 pu.
Preferably, in step S2, the first delay time is 0.5 seconds.
Preferably, the second delay time of the grid-connected point electrical state detection is not less than 1.0 second.
Preferably, the grid-connected point electrical states to be detected are voltage, current and phase.
Preferably, the circuit breaker is under three-stage current protection control.
The invention has the substantial effects that the distributed energy in the fault area can be isolated in time, the condition that the electric arc is not extinguished or the non-synchronous switching-on occurs in the reclosing process is avoided, and the transient fault cannot be developed into the permanent fault.
Drawings
Figure 1 is a diagram of a distribution line including a distributed energy source;
FIG. 2 is a diagram of an AND topology;
FIG. 3 is an AND graph model of FIG. 2;
FIG. 4 is an exemplary diagram of pre-reclosing acceleration protection;
FIG. 5 is an exemplary diagram of post-reclosing acceleration protection;
FIG. 6 is a flow chart of a protection method of the present invention;
FIG. 7 is a schematic illustration of a fault location result of the present invention;
fig. 8 is a schematic diagram of the operation of a circuit breaker according to the present invention;
fig. 9 is a timing diagram of a DG side circuit breaker state of the present invention;
FIG. 10 is a schematic diagram of a reclosing process for a distribution network in accordance with the present invention;
fig. 11 is another DG side circuit breaker state timing diagram of the present invention;
fig. 12 is a schematic diagram of another reclosing process for a distribution network in accordance with the present invention.
Detailed Description
The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings.
Example (b):
effect of DG on Current protection
In the distribution line containing DG shown in fig. 1, 1 and 2 are 2 protection devices, respectively, and A, B, C are 3 bus bars, wherein 1 DG is connected between bus bar a and bus bar B.
1) The protection device is located downstream of the DG
When f is1When short-circuit fault occurs, the short-circuit current of the system and the DG output flows simultaneouslyTo the fault point f1Due to the boosting effect of the DG, the current value at the protection 2 is increased, and the possibility of misoperation is high, and the larger the DG capacity is, the higher the possibility of misoperation of the protection 2 is.
2) The protection device being located upstream of the DG
When f is2When short-circuit fault occurs, short-circuit current output by the system and the DG simultaneously flows to a fault point f2, and the short-circuit current provided by the DG can raise the voltage of a grid-connected point, so that the current value at the protection 1 position is reduced, the sensitivity is reduced, the probability of motion rejection is provided, and the larger the DG capacity is, the higher the probability of motion rejection of the protection 1 is.
(1) ADN graph model
The analysis of the current protection after the DG is connected shows that the conventional current protection based on the absolute value of the current is no longer effective due to the connection of the DG. Therefore, the invention provides an active power distribution network protection scheme suitable for DG access according to the fault current characteristics of DGs and the influence of the fault current characteristics on the traditional current protection.
Considering the practical application scenario that the measurement capability of each small area in one distribution network area is different, the protection scheme based on the multi-terminal current direction of the area aims at the small area of the distribution network with the voltage, current amplitude and phase measurement capability, and therefore the small area is further processed in a partitioning mode. An ADN with a radial topology as shown in fig. 2 is built, which contains the system power supply, the circuit breaker, the DG and the loads, where the arrows indicate the loads connected at the bus.
In the ADN topology, a power distribution network area surrounded by circuit breakers is used as a unit protection area (that is, the circuit breakers are not included in the unit protection area), and the circuit breakers are used as a connection path between two unit protection areas, so that the power distribution network is divided into a plurality of unit protection areas. Establishing a power distribution network graph model corresponding to the power distribution network with the topological structure shown in FIG. 2, as shown in FIG. 3, wherein A1～A7Is 7 unit protection areas, B1～B6Is 6 circuit breakers. The protection areas of each unit are set with numbers, and the current direction flows from the small-number area to the large-number area as the positive current reference direction (by using the breaker B in figure 3)3For example, when the current flows from the region A1Flow direction area A4When the current direction is positive). Defining the small-number area side connected with the breaker as the upstream area and the large-number area side as the downstream area (refer to B in FIG. 3)4For example, A1～A4Is the upstream area thereof, A5～A7The downstream region thereof).
(2) Matrix definition
1) The incidence matrix describes the position relationship between each protection unit area and each breaker in the form of incidence matrix, and the elements of the incidence matrix can be defined as follows:
in the formula, the i row element of the correlation matrix is the positional relationship between the area i and each breaker. By way of example, as can be seen from the topology shown in FIG. 3, region A3Is a circuit breaker B2Is associated with the matrix element c32-1; region A1Is a circuit breaker B1、B3、B4Is associated with the matrix element c11＝c13＝c14＝1。
2) Fault information matrix
Fault location criterion: if the current at the breaker is in the positive direction (namely the current flows from the small-number area to the large-number area) before the fault occurs, after the fault occurs, when the current direction is unchanged and the amplitude is increased, the fault is located in the downstream area of the breaker; when the current direction is unchanged and the amplitude is reduced or the direction is changed, the fault is positioned in the upstream area of the circuit breaker; if the current at the breaker is in the negative direction (i.e. the current flows from the large-number area to the small-number area) before the fault occurs, the fault is located in the upstream area of the breaker after the fault occurs when the current direction is unchanged and the amplitude is increased; when the current direction is unchanged and the magnitude decreases or the direction changes, the fault is located in the downstream region of the circuit breaker.
According to the method, the direction of the current fault component is judged to form a fault information matrix DFComprises the following steps:
DF＝[D1,D2,...,Dj]T (1.10)
(3) fault area location
When the active power distribution network has a fault, the fault point is the lowest potential point in the fault component network, so that the current fault component flows from other areas to the area where the fault point is located. Defining a current fault component direction variable EijComprises the following steps:
Eij＝cijDF·j (1.11)
wherein i is the zone number and j is the breaker number. EijRepresenting the direction of the current fault component at breaker j. If E ij1, the current fault component flows from breaker j to zone i; if EijThe current fault component flows from zone i to breaker j at-1. Definition of
The sum of the direction variables of the current fault components at each breaker connected with the area i, the fault area criterion of the protection scheme is as follows:
and pre-storing the serial numbers of the circuit breakers at the periphery of each area in the protection device at the circuit breaker. After the area i where the fault is located is determined according to the formula (1.12), the protection device sends an action signal to circuit breakers at the periphery of the area i, and the isolation of the fault area is completed.
(4) Influence of DG access on reclosure technology
1) Influence of DG on pre-reclose acceleration protection in the distribution line shown in fig. 4, a pre-reclose acceleration protection device is installed in a protection device P21 of the feeder 2. When the fault is located at the upstream of the DG, taking the P point as an example of the occurrence of the short-circuit fault, the P21 protects the transient action, and at this time, if the DG is not isolated in time, the output short-circuit current will flow to the fault point, so that the arc at the fault point P cannot be extinguished naturally. After a period of time, reclosing operation is carried out at P21, and reclosing fails because the arc at the fault point is not extinguished. If a fault cannot be located and removed in a short time, the transient fault may be transformed into a permanent fault. When the fault is located at the downstream of the DG, taking the short-circuit fault at the M point as an example, the P21 point protects the instantaneous action, at this time, if the DG is not isolated in time, the output short-circuit current flows to the fault point, and if the DG capacity is large and the short-circuit current level is high, the selective action of protecting the P23 is triggered to complete the fault isolation. And after a period of time, the protection P21 carries out reclosing operation, and the reclosing is successful. However, since the DG is in an islanding operation state during reclosing, there is a risk of non-synchronous reclosing.
2) Influence of DG on post-automatic reclosing acceleration protection
In the distribution line shown in fig. 5, the post-reclose acceleration protection devices are installed in the protection devices P21, P22, and P23 of the feeder 2. When the fault is positioned at the upstream of the DG, taking the P point with short circuit fault as an example, the P21 is finally selectively operated through the setting coordination among the protection P21, the P22 and the P23. If the DG is not isolated, the risk that transient faults are developed into permanent faults exists, reclosing at the position P21 fails, and acceleration action is protected; if the DG is isolated, the fault at the P21 position is self-recovered, and the reclosing is successful. When the fault is located at the downstream of the DG, taking the short-circuit fault at the M point as an example, the P23 selectively acts through the setting coordination among the protection P21, the P22 and the P23, and then the P23 is successfully superposed. Therefore, the influence of the access of the DG on the acceleration protection before the automatic reclosing is relatively large, and the problems that the transient fault is changed into the permanent fault and the asynchronous reclosing exists. For the acceleration protection after the automatic reclosing, only the problem that the transient fault is converted into the permanent fault exists.
(2) Scheme flow
Although the protection scheme based on the regional multi-terminal current direction can effectively solve the problem that the DG access affects the protection of the power distribution network, the protection scheme requires that a protection device at a breaker of the power distribution network has the amplitude and phase measurement capabilities of voltage and current at the same time.
For a small area of the power distribution network with only the current measurement capability, the scheme considers that a relay protection scheme with adaptability to the access of a Distributed Generation (DG) is realized by matching an acceleration before reclosing (installed on a line outlet side) and a DG re-grid-connection time sequence on the basis of conventional protection configuration, namely three-section current protection, and the action logic of the scheme is as shown in FIG. 6 and mainly comprises the following steps:
1) and (3) fault detection: and detecting the voltage of the DG grid-connected point in real time, and immediately disconnecting the DG from the power distribution network once detecting that the voltage of the DG grid-connected point falls down due to the fault in the power distribution network. At this time, the power distribution network does not contain a DG any more, and the traditional single-power-supply radial topology structure is changed.
2) Reclosing action: the feeder is cut off by a front acceleration reclosing device arranged at the outlet side of the line without selectivity, and the feeder is reclosed after a certain time delay (manually set), wherein DG keeps an off-grid state. At the moment, the DG finishes off-grid operation, so that the phenomenon of non-synchronous closing can not occur.
3) And (3) detecting the state of the grid-connected point: and detecting whether the electrical state of the grid-connected point meets the requirement of DG synchronous grid connection. If the grid connection requirement is met, the fault is instantaneous, and the power distribution network recovers to a normal running state through reclosing operation, or the fault is permanent and the DG access position is located at the upstream of a fault point, and the DG can be reconnected to the power distribution network under the two conditions; if the grid connection requirement is not met, the fault is permanent, the DG is positioned at the downstream of the fault point, and the reclosing operation cannot complete fault recovery. At the moment, the DG is not protected in the power distribution network, the breaker which needs to act can be accurately judged through the three-section type current protection configured in the power distribution network, and the breaker can selectively act on tripping to complete fault removal. Before the fault is removed, the DG always remains off-grid.
Analytical validation
In order to verify the effectiveness of the protection scheme, a typical 10kV radial distribution network model as shown in fig. 2 is established by using PSCAD/EMTDC, and the topology of the distribution network is shown in fig. 3. The system frequency is 50Hz and the line parameters and load are equivalent in the form of a combination of resistance and inductance. DG in the power distribution network is an inverter type DG under a PQ control mode, a current limiter is added in an inverter control loop, and short-circuit current of the inverter is limited within 2 pu.
(1) Protection scheme based on regional multi-terminal current direction
The correlation matrix can be obtained from equation (1.9) as:
the simulation duration is set to 0.5s, at time A at 0.2s4An AB two-phase short circuit grounding fault is introduced, and the fault duration is 0.1 s. The fault information matrix at this time can be obtained according to equation (1.10) as follows:
[1 1 -1 1 1 1]T (1.14)
the available fault location information table according to equation (1.11) is as follows:
by combining the fault location information of each area in the table and the fault area location criterion shown in the formula (1.12), it can be known that the fault is located in the area 4. The fault location simulation result is shown in fig. 7, and the fault area number is 4. The protection device sends an action signal to a corresponding circuit breaker according to the fault positioning result, and the circuit breaker B3The operation was performed at 0.2s, as shown in FIG. 8.
(2) Protection scheme considering DG grid-connected condition
1)A3Internal transient two-phase short circuit
When t is 0.5s, A3A transient two-phase short circuit occurs. As can be seen from fig. 9, when t is 0.54s, the DG grid-connected point breaker BS is open, and DG is off-grid. As can be seen from fig. 10, B is 0.54s at t1And disconnecting and overlapping after 0.5s of delay. The three-section current protection does not act, which indicates that the fault is instantaneous and the reclosing is successful. And detecting the voltage of the grid-connected point by DG with a certain delay, finding that the fault in the power distribution network is removed, and connecting the grid at 1.19s, as shown in FIG. 9.
2)A3Permanent two-phase short circuit occurs in
When t is 0.5s, area A3Permanent short of two phases of AB internallyThe circuit fault, circuit breaker BS opens at 0.54s in fig. 11, DG leaves the grid. As can be seen from FIG. 12, B1Tripping at 0.54s, sending out coincidence signal after 0.5s delay, and switching off the circuit breaker B at 1.04s1Closed, three-stage current protection selectively acting due to permanent failure, B2Action removes the fault at 1.11 s. The DG detects the grid-connected point voltage after a certain time delay, and because the fault is permanent, the three-section type current protection selectively acts, so that the grid-connected condition is not satisfied all the time, and the DG is in an off-grid state, that is, the circuit breaker BS is always off, as shown in fig. 11. The simulation results are identical with theoretical analysis, and the effectiveness of the protection scheme is proved.
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.
Although the terms protection, reclosing etc. are used more here, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.
Claims (9)
1. The protection method of the power distribution network under the distributed energy condition is characterized in that a plurality of circuit breakers are arranged in the power distribution network, the distributed energy and the power distribution network are connected through the circuit breakers, a current measuring device is arranged at the position of each circuit breaker, an acceleration protection device before reclosing is installed on the outlet side of a circuit, and the protection method of the power distribution network specifically comprises the following steps:
s1, fault detection: positioning the fault occurrence position, and controlling the action of a breaker to isolate the fault area; detecting the voltage of a distributed energy grid-connected point in real time, and immediately disconnecting the distributed energy from the power distribution network once the voltage drop of the distributed energy grid-connected point caused by the fault in the power distribution network is detected;
s2, reclosing action: after the first time delay, the feeder line where the fault area is located is superposed, the fault area is accessed, if the fault is transient, the access state is kept, and if the fault still exists, the fault area is isolated and disconnected again;
s3, detecting the state of the point-to-point: and detecting the electrical state of the grid-connected point of the distributed energy sources after a second delay, accessing the distributed energy sources to the power distribution network if the grid-connected point of the distributed energy sources is recovered to be normal, and otherwise, keeping the off-grid state of the distributed energy sources.
2. The method for protecting an electric distribution network under distributed energy conditions according to claim 1, wherein the method for fault location is as follows:
the distribution network region that encloses each circuit breaker is regarded as the unit protection area, no longer contains the circuit breaker in the unit protection area, the circuit breaker is as the connecting channel between two unit protection areas, for the regional serial number of setting for each unit protection, it is regional current reference positive direction to get the current direction by the regional flow of little serial number to the regional big serial number, it is regional for the upstream of circuit breaker that the regional one side of little serial number that the circuit breaker is connected is defined, the big serial number one side that the circuit breaker is connected is regional for the downstream of circuit breaker, the fault judgement basis is as follows:
Eij＝cijDF·j
DF·j＝[D1,D2,…,Dj]T
in the formula, cijFor the elements of the associative matrix, EijFor circuit breaker BjIn the direction of the current fault component, if Eij1, the current fault component is determined by the circuit breaker BjFlow direction area Ai(ii) a If EijIf-1, the current fault component is represented by region aiFlow direction breaker Bj；DF·jAs a fault information matrix, D1As a current fault component of the 1 st circuit breakerDirection of (D)2To DjAnd so on.
3. A method for protection of an electric distribution network under distributed energy conditions, according to claim 2, characterized in that the correlation matrix elements are determined by:
Aiis the ith area, BjIs the jth breaker.
4. A method for protection of an electric distribution network under distributed energy conditions, according to claim 3, characterized in that the fault information matrix is determined by:
if the fault occurs before, the breaker B1When the current is positive, and the current direction is unchanged and the amplitude is increased after the fault occurs, D1Is 1; when the current direction is unchanged and the amplitude decreases or the direction changes, D1Is-1; if the current at the breaker is in the negative direction before the fault occurs, D is determined when the current direction is unchanged and the amplitude is increased after the fault occurs1Is-1; when the current direction is unchanged and the amplitude decreases or the direction changes, D1Is 1; d2To DjDetermined in the same way.
5. The method according to claim 1 or 2, wherein the distributed energy source is an inverter distributed energy source under a PQ control mode, a current limiter is added to an inverter circuit, and the short-circuit current is limited to 2 pu.
6. The method according to claim 1, wherein the first delay time in step S2 is 0.5 seconds.
7. The method according to claim 6, wherein the second delay of the grid-connected point electrical status detection is not less than 1.0 second.
8. The method according to claim 7, wherein the grid-connected point electrical states to be detected are voltage, current and phase.
9. The method according to claim 1, wherein the circuit breaker is a three-stage current protection circuit breaker.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111443220.8A CN114123136B (en) | 2021-11-30 | 2021-11-30 | Protection method for power distribution network under distributed energy condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111443220.8A CN114123136B (en) | 2021-11-30 | 2021-11-30 | Protection method for power distribution network under distributed energy condition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114123136A true CN114123136A (en) | 2022-03-01 |
| CN114123136B CN114123136B (en) | 2024-08-20 |
Family
ID=80368812
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111443220.8A Active CN114123136B (en) | 2021-11-30 | 2021-11-30 | Protection method for power distribution network under distributed energy condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114123136B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116979478A (en) * | 2023-09-25 | 2023-10-31 | 广东电网有限责任公司中山供电局 | Reclosing control method and system based on improved anti-islanding protection strategy |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108173249A (en) * | 2018-01-10 | 2018-06-15 | 东南大学 | A kind of distribution network failure zone location algorithm for considering inverse distributed power access |
| CN108832606A (en) * | 2018-06-21 | 2018-11-16 | 东南大学 | It is a kind of meter and region measurement capability active distribution network protection scheme |
| WO2018214810A1 (en) * | 2017-05-22 | 2018-11-29 | 国网浙江省电力公司宁波供电公司 | Method and apparatus for controlling voltage of distributed photovoltaic power distribution network |
| US20180366937A1 (en) * | 2017-06-20 | 2018-12-20 | Florida Power & Light Company | Coordinated reclosing in a power distribution system |
-
2021
- 2021-11-30 CN CN202111443220.8A patent/CN114123136B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018214810A1 (en) * | 2017-05-22 | 2018-11-29 | 国网浙江省电力公司宁波供电公司 | Method and apparatus for controlling voltage of distributed photovoltaic power distribution network |
| US20180366937A1 (en) * | 2017-06-20 | 2018-12-20 | Florida Power & Light Company | Coordinated reclosing in a power distribution system |
| CN108173249A (en) * | 2018-01-10 | 2018-06-15 | 东南大学 | A kind of distribution network failure zone location algorithm for considering inverse distributed power access |
| CN108832606A (en) * | 2018-06-21 | 2018-11-16 | 东南大学 | It is a kind of meter and region measurement capability active distribution network protection scheme |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116979478A (en) * | 2023-09-25 | 2023-10-31 | 广东电网有限责任公司中山供电局 | Reclosing control method and system based on improved anti-islanding protection strategy |
| CN116979478B (en) * | 2023-09-25 | 2024-01-23 | 广东电网有限责任公司中山供电局 | Reclosing control method and system based on improved anti-islanding protection strategy |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114123136B (en) | 2024-08-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102124287B1 (en) | How to arrange switches and eliminate faults in the converter station for flexible DC | |
| Rezaei et al. | An analytical review on state-of-the-art microgrid protective relaying and coordination techniques | |
| Bayati et al. | A fuse saving scheme for DC microgrids with high penetration of renewable energy resources | |
| CN105207178B (en) | A kind of based on the DG Distribution Network Failure accessed location and isolated island division methods | |
| CN108957245A (en) | A kind of flexible direct current power distribution network monopole fault identification method based on total failure electric current | |
| Meghwani et al. | Analysis of fault characteristics in DC microgrids for various converter topologies | |
| Kontos et al. | Fast DC fault recovery technique for H-bridge MMC-based HVDC networks | |
| CN114123136A (en) | Protection method for power distribution network under distributed energy condition | |
| Saleh et al. | Synthetic harmonic distance relaying for inverter-based islanded microgrids | |
| Psaras et al. | DC fault management strategy for continuous operation of HVDC grids based on customized hybrid MMC | |
| CN105703341B (en) | There is the layering point domain isolated island guard method of anti-jump function for large-scale wind power | |
| Ibrahim et al. | On the DC Microgrids Protection Challenges, Schemes, and Devices‐A Review | |
| Zhao et al. | Coordinated Control of DC Circuit Breakers in Multilink HVDC Grids | |
| CN108418193B (en) | Fault power supply recovery method and system combining reclosing and low voltage ride through | |
| CN109193608A (en) | A kind of capacitance-resistance type blended learning suitable for DC grid | |
| Rahman et al. | DC fault protection of multi-terminal HVDC systems using DC network partition and DC circuit breakers | |
| Vijitha et al. | Short circuit analysis and adaptive zonal protection of distribution system with distributed generators | |
| Alexis | Distributed generation on phase-to-phase short circuit protection in distribution network | |
| Lazzari et al. | Analysis and Design of the Protection Scheme for a LVDC Microgrid | |
| CN109800481B (en) | Method for checking correctness of secondary virtual loop of 110kV backup power automatic switching SCD (substation configuration description) file of intelligent substation | |
| Rezaei et al. | State-of-the-Art microgrid power protective relaying and coordination techniques | |
| CN113131452A (en) | Backup protection acceleration method and system for flexible direct current power distribution network | |
| Ntshiba et al. | Digital Implementation of an Auto-Reclose Protection Scheme for a Distribution System | |
| Amer et al. | An Overview in Protection Coordination Methods for Mitigation DGs Penetration in Distribution System.(Dept. E) | |
| US20130188285A1 (en) | Method of operating integrated circuit breaker module for solar power 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 |