CN107272645A - The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical - Google Patents
The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical Download PDFInfo
- Publication number
- CN107272645A CN107272645A CN201710508619.7A CN201710508619A CN107272645A CN 107272645 A CN107272645 A CN 107272645A CN 201710508619 A CN201710508619 A CN 201710508619A CN 107272645 A CN107272645 A CN 107272645A
- Authority
- CN
- China
- Prior art keywords
- photovoltaic
- line
- sequence
- fault
- failure
- 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
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B23/00—Testing or monitoring of control systems or parts thereof
- G05B23/02—Electric testing or monitoring
- G05B23/0205—Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults
- G05B23/0259—Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults characterized by the response to fault detection
- G05B23/0275—Fault isolation and identification, e.g. classify fault; estimate cause or root of failure
- G05B23/0281—Quantitative, e.g. mathematical distance; Clustering; Neural networks; Statistical analysis
Landscapes
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mathematical Analysis (AREA)
- Evolutionary Computation (AREA)
- Artificial Intelligence (AREA)
- Algebra (AREA)
- Mathematical Optimization (AREA)
- Mathematical Physics (AREA)
- Probability & Statistics with Applications (AREA)
- Pure & Applied Mathematics (AREA)
- Automation & Control Theory (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical, based on the inverter failure Equivalent Model with low voltage crossing control strategy, photovoltaic electric station grid connection system containing Neutral Grounding through Resistance in Electrical is modeled, collect the respective characteristic of class circuit of circuit two in system line and station for the grid-connected system, calculation of fault model is established respectively.Fault network nonlinear multivariable equation group can be obtained with reference to each sequence network equation and corresponding failure boundary condition of the line fault computation model, then convergence solution is tried to achieve with Newton-Laphson iteration construction iterated revision equation, realizes accident analysis.More than grid-connected photovoltaic power station by the way of Neutral Point Through Low Resistance; the present invention solves the problems, such as the fault modeling of the system; that especially collects line fault computation model in station is established as complete analysis line fault there is provided possible; influence of the neutral resistance to system zero-sequence network is fully taken into account, foundation is provided for follow-up design protection.
Description
Technical field
The present invention relates to solar energy power generating and technical field of electric power transmission, more particularly to a kind of Neutral Grounding through Resistance in Electrical
Photovoltaic electric station grid connection fault model, the present invention a kind of photovoltaic electric station grid connection failure based on Neutral Grounding through Resistance in Electrical is also provided
The analysis method of model.
Background technology
With being constantly connected to the grid for large-sized photovoltaic power station, electric power system fault incidence inevitably increases, and
Transmission line of electricity short circuit current flow size is consequently increased, and can exceed that the maximum current ability to bear of some force devices, so that
Cause cascading failure.Therefore, it is necessary to carry out power network according to the maximum short circuit current being likely to occur after large-sized photovoltaic electric station grid connection
Build with improving.Then, the calculation of fault in the power station containing large-sized photovoltaic turns into one of development photovoltaic power generation technology top priority.
The case study that conventional failure is analyzed to large-sized photovoltaic electric station grid connection is also relatively fewer, and does not account for photovoltaic mostly
The Fault Control strategy and the situation of Neutral Grounding through Resistance in Electrical in power station, inevitably result in the limitation of calculation of fault.
The content of the invention
It is an object of the invention to provide a kind of photovoltaic electric station grid connection fault model of Neutral Grounding through Resistance in Electrical, the present invention
Another object be to provide a kind of analysis method of the photovoltaic electric station grid connection fault model based on Neutral Grounding through Resistance in Electrical.
The present invention realizes that above-mentioned purpose is adopted the technical scheme that：A kind of photovoltaic electric station grid connection of Neutral Grounding through Resistance in Electrical
Fault model, including basic model is set up to the photovoltaic electric station grid connection system containing Neutral Grounding through Resistance in Electrical, system line is set up
Road calculation of fault model and collect line fault computation model；It is described in detail below：
(1) based on the inverter failure Equivalent Model with low voltage crossing control strategy, to containing neutral point through resistance
The photovoltaic electric station grid connection system of ground connection sets up basic model；The three-phase output voltage and three-phase of photovoltaic DC-to-AC converter are defeated during including failure
Go out electric current；Electric current and voltage that the photovoltaic DC-to-AC converter defined according to instantaneous reactive power theory is exported；Three-phase instantaneous active power；
Three-phase instantaneous reactive power；In Voltage Drop, inverter is for the stabilization for the active reactive power for maintaining output of trying one's best, inversion
The active and reactive reference value of device output current reference value and any photovoltaic DC-to-AC converter.
(2) be directed to the photovoltaic electric station grid connection system containing Neutral Grounding through Resistance in Electrical two class circuits --- system line and
Collect the respective characteristic of circuit in standing, accordingly set up system line calculation of fault model and collect line fault computation model.
(3) when failure occurs on system line, whole photovoltaic plant is equivalent to the power supply of a Large Copacity, and be in
The characteristic of existing voltage-controlled current source, sets up positive and negative zero-sequence network model respectively, takes the photovoltaic current source that positive sequence is controlled containing only positive sequence
Component, injects positive sequence network, negative phase-sequence and zero-sequence network do not contain power supply.
(4) when failure occurs to collect on circuit in photovoltaic station, it is impossible to whole photovoltaic station is equivalent into a power supply again,
Will non-failure collect line and failure to collect line difference equivalent.Non- failure collects line and is equivalent to a controlled current source, and failure is converged
Line concentration disconnects from trouble point is equivalent to two power supplys, if trouble point is located at cable ZCfOn, then collection bus is to failure cable ZCfIt
Between inverter group be equivalent to a controlled current source, ZCfTo the inverter group collected between line end be equivalent to another by
Control current source.Whole grid-connected system will be equivalent to the network of a system power supply and three photo-voltaic power supplies, and positive negative zero is set up respectively
Sequence network model, each photovoltaic current source injects respective positive sequence short circuit current flow in positive sequence network, negative phase-sequence and zero-sequence network
Power supply is not contained.
A kind of analysis method of the photovoltaic electric station grid connection fault model based on Neutral Grounding through Resistance in Electrical, it is characterised in that：
The system line calculation of fault model that photovoltaic electric station grid connection fault model step (2) based on Neutral Grounding through Resistance in Electrical is set up,
Photo-voltaic power supply is handled as controlled source, with reference to the boundary condition of various fault types, you can obtain fault network polynary non-
System of linear equations；Then convergence solution is tried to achieve with Newton-Laphson iteration construction iterated revision equation, realizes accident analysis.With allusion quotation
Exemplified by type photovoltaic electric station grid connection, such as Fig. 1 networks：
(1) when failure occurs on system line, there is positive and negative zero-sequence network such as Fig. 2, then each branch impedances of Fig. 2 are gone here and there
Parallel connection merges, and obtains equivalent network such as Fig. 3 of positive and negative zero sequence.When singlephase earth fault occurs for system line, connect with reference to single-phase
Earth fault boundary condition：That is the relation of the positive and negative residual voltage electric current of earth point, be
Unite line single phase grounding failure compound sequence network Fig. 4, and then obtains loop current equation group by the loop method of analysis；WhereinFor trouble point positive and negative residual voltage over the ground,For trouble point
Positive and negative zero-sequence current.
In formula (1), Ii：Loop i loop current；ZS35：35kV system positive sequence equivalent impedances；ZL351：M buses are to trouble point
Line impedance between K；ZT：Photovoltaic source Equivalent Transformer impedance；ES：35kV system phase voltages；Photo-voltaic power supply terminal voltage；Photovoltaic source fault current；Z∑0：Zero sequence synthetic impedance；P*And Q*The active and idle ginseng of inverter control during for fault traversing z
Examine value.
In conjunction with the inverter described in the photovoltaic electric station grid connection fault model step (1) based on Neutral Grounding through Resistance in Electrical
Failure Equivalent Model, the non-linear solution equation group for setting up system line singlephase earth fault is as follows：
In formula (2), ZS35:35kV system positive sequence equivalent impedances；ZL351:M buses are to the line impedance between the K of trouble point；ZT:
Photovoltaic source Equivalent Transformer impedance；Z∑0:Zero sequence synthetic impedance；ES:35kV system phase voltages；Photo-voltaic power supply terminal voltage；
Photovoltaic source fault current；Trouble point zero-sequence current；
η is the capacity coefficient of inverter after failure, For photo-voltaic power supply terminal voltage positive sequence after failure
Component；ImaxFor inverter maximum allowed current, according to newest standards Imax=1.5In；Sn、UnAnd InFor inverter rated capacity,
Voltage and current；kqFor reactive power support coefficient；P*And Q*Inverter exports active and idle reference value during for failure；WithFor
Inverter exports active and idle reference value during normal operation.
Formula (2) is the solution equation group of system line singlephase earth fault, is hadFive unknown numbers,
fx=[f1f2f3f4f5]TFive equations, can be solved, but be due to the non-linear relation of equation, it is impossible to directly try to achieve analytic solutions,
So trying to achieve convergence solution with Newton-Laphson iteration construction iterated revision equation, realize that singlephase earth fault is analyzed.
(2) what the photovoltaic electric station grid connection fault model step (2) based on Neutral Grounding through Resistance in Electrical was set up collects circuit event
Hinder computation model, be further carried out accident analysis；Each branch impedance in the positive and negative zero-sequence network topological diagram 5 of line fault will be collected
Connection in series-parallel merging is done, equivalent network Fig. 6 of positive and negative zero sequence is obtained.
When collecting circuit generation singlephase earth fault in photovoltaic station, with reference to boundary condition：The relation of positive and negative zero-sequence current voltage at failure, whereinFor trouble point over the ground
Positive and negative residual voltage,For the positive and negative zero-sequence current of trouble point), i.e. the relation of the positive and negative residual voltage electric current of earth point,
Obtain collecting line single phase grounding failure compound sequence network Fig. 7, loop current equation group is obtained by the loop method of analysis；
In formula (3), Ii：Loop i loop current；ZS35：35kV system positive sequence equivalent impedances；ZL35：35kV line impedances；
ZT40：Non-faulting collects line photovoltaic source Equivalent Transformer impedance；ZTm,ZTn1：Failure collects line photovoltaic source Equivalent Transformer impedance；
ES：35kV system phase voltages；Non-faulting collects the equivalent photovoltaic source voltage terminal of line and fault current；Collect mother
Photovoltaic inversion equivalent source terminal voltage and fault current between line and trouble point；Trouble point to collect line end photovoltaic
Inversion equivalent source terminal voltage and fault current；Z∑0：Zero sequence synthetic impedance；Z∑2：Negative phase-sequence comprehensive impedance.
In conjunction with the photovoltaic inversion described in the photovoltaic electric station grid connection fault model step (1) based on Neutral Grounding through Resistance in Electrical
Power failure Equivalent Model, collects line fault computation model and contains a system power supply and three photo-voltaic power supplies, each photovoltaic
Power supply has the current equation and active reactive equation of oneself, sets up the non-linear solution that photovoltaic collects line single phase grounding failure
Equation group is as follows：
In formula (4)~(7),Trouble point zero-sequence current；ZS35：35kV system positive sequence equivalent impedances；ZL35：35kV circuits
Impedance；ZT40：Non-faulting collects line photovoltaic source Equivalent Transformer impedance；ZTm,ZTn1：Failure collects the resistance of line photovoltaic source Equivalent Transformer
It is anti-；Zm:Cable positive-negative sequence impedance between collection bus and trouble point；ZCf1:The line impedance of failure cable；ES：35kV system phases
Voltage；
Collect line fault computation model and contain three photovoltaic current sources, each photovoltaic source have oneself current equation and
Active reactive equation：
Non-faulting collects the equivalent photovoltaic source voltage terminal of line and fault current；η40SFor the equivalent photovoltaic inversion electricity
The capacity coefficient in source, WithThe equivalent Photovoltaic Inverter output is active and idle during for failure
Reference value；WithInverter exports active and idle reference value during for normal operation.
Photovoltaic inversion equivalent source terminal voltage and fault current between collection bus and trouble point；ηmSFor this etc.
The capacity coefficient of Photovoltaic Inverter is imitated, WithEquivalent Photovoltaic Inverter output during for failure
Active and idle reference value；WithInverter exports active and idle reference value during for normal operation.
Trouble point to collect line end photovoltaic inversion equivalent source terminal voltage and fault current；ηnSIt is equivalent for this
The capacity coefficient of Photovoltaic Inverter, WithThere is the equivalent Photovoltaic Inverter output during for failure
Work(and idle reference value；WithInverter exports active and idle reference value during for normal operation.
Formula (4)~(7), have 13 equations and
13 unknown numbers, equally try to achieve convergence solution with Newton-Laphson iteration construction iterated revision equation, realize that photovoltaic collects line
Road singlephase earth fault analysis.
Grid-connected photovoltaic power station is more and more by the way of Neutral Point Through Low Resistance, and the present invention is solved through resistance
The line fault computation modeling problem of the photovoltaic electric station grid connection system of ground connection, especially collects line fault meter in photovoltaic plant station
The intactly analysis circuit failure that is established as calculating model, there is provided possible, has taken into full account neutral resistance to grid-connected system
The influence of zero-sequence network, can easily try to achieve the short circuit current flow especially zero-sequence current and node electricity under various fault conditions
Pressure, foundation is provided for follow-up protection scheme design, especially for adjusting and verify there is provided foundation for circuit zero-sequenceprotection,
Photovoltaic station grid-connected system is solved quickly to cut off earth fault to avoid the problem of failure propagation causes photovoltaic large area off-grid.
Brief description of the drawings
Fig. 1 is the photovoltaic station grid-connected system for the Neutral Grounding through Resistance in Electrical studied in the inventive method embodiment；
Wherein ZS330：330kV system impedances；ZL110：110kV line impedances；ZL35：35kV line impedances；L1~L5：Five
Photovoltaic collects circuit in station；T1：330kV main transformers；T2：110kV step-up transformers；Rg：Neutral resistance；ZC1~
ZC10：Collect circuit first paragraph~ten section cable resistance；1：Collect route protection, 2：System line is protected.
Fig. 2 is the positive and negative zero-sequence network topological diagram of system line failure in the inventive method embodiment；
(a) (b) (c) is respectively positive and negative zero sequence topological diagram；Wherein330kV system impedances；The positive and negative zero sequence line impedances of 110kV；M buses are to the positive and negative zero sequence between the K of trouble point
Line impedance；Positive sequence line impedance between K to the N buses of trouble point；330kV main transformer pressures
The positive and negative zero sequence impedance of device；330kV main transformers are to ground leg zero sequence impedance；110kV step-up transformers are just
Negative zero sequence impedance；110kV step-up transformers are to ground leg zero sequence impedance；The positive and negative zero impedance of case transformer；The terminal voltage of photovoltaic current source；Photovoltaic source positive sequence fault current；Trouble point positive and negative residual voltage over the ground.
Fig. 3 is each sequence equivalent network figure of system line failure in the inventive method embodiment；
Wherein,35kV system positive sequence equivalent impedances；
35kV system negative phase-sequence equiva lent impedances；35kV system zero sequence equiva lent impedances；
Rg is neutral resistance；The positive and negative zero-sequence current of trouble point.
Fig. 4 is line single phase grounding failure compound sequence network figure in the inventive method embodiment；
Wherein Ii：Loop i loop current；Positive-negative sequence impedance is equal, and 35kV system positive-negative sequences are equivalent
Impedance；Photo-voltaic power supply Equivalent Transformer positive-negative sequence impedance；Zero
Sequence comprehensive impedance.
Fig. 5 is to collect the positive and negative zero-sequence network topological diagram of line fault in the inventive method embodiment；
(a) (b) (c) is respectively positive and negative zero sequence topological diagram；Wherein330kV system impedances；The positive and negative zero sequence line impedances of 110kV；The positive and negative zero sequence line impedances of 35kV；The positive and negative zero sequence impedance of 330kV main transformers；330kV main transformers are to ground leg zero sequence impedance；The positive and negative zero sequence impedance of 110kV step-up transformers；110kV step-up transformers are to ground leg zero sequence impedance；Trouble point upstream failure cable run impedance；Trouble point downstream failure cable circuit hinders
It is anti-；The positive and negative zero sequence impedance of cable between collection bus and trouble point；Trouble point to collect line end
The positive and negative zero sequence impedance of cable；Non-faulting collects line photovoltaic source Equivalent Transformer positive sequence impedance；Collect line in trouble point upstream
Photovoltaic source Equivalent Transformer positive sequence impedance；Trouble point downstream collects line photovoltaic source Equivalent Transformer positive sequence impedance；
Non-faulting collects the equivalent photovoltaic source voltage terminal of line and fault current；Photovoltaic inversion between collection bus and trouble point etc.
Imitate power supply terminal voltage and fault current；Trouble point to collect line end photovoltaic inversion equivalent source terminal voltage and failure
Electric current；Rg：Neutral resistance；Trouble point positive and negative residual voltage over the ground.
Fig. 6 is to collect each sequence equivalent network figure of line fault in the inventive method embodiment；
Wherein,35kV system positive sequence equivalent impedances；
35kV system negative phase-sequence equiva lent impedances；The equivalent resistance of 35kV systems zero sequence
It is anti-；The positive and negative zero-sequence current of trouble point.
Fig. 7 is to collect line fault single-phase earthing compound sequence network figure in the inventive method embodiment.
Wherein Ii：Loop i loop current；Positive-negative sequence impedance is equal, and 35kV system positive-negative sequences are equivalent
Impedance；35kV line impedances；Cable positive-negative sequence resistance between collection bus and trouble point
It is anti-；Trouble point upstream failure cable run positive-negative sequence impedance；Collect line in downstream
Photovoltaic source Equivalent Transformer positive sequence impedance；Zero sequence synthetic impedance；Negative phase-sequence comprehensive impedance.
Embodiment
A kind of photovoltaic electric station grid connection fault model of Neutral Grounding through Resistance in Electrical, including to containing Neutral Grounding through Resistance in Electrical
Photovoltaic electric station grid connection system set up basic model, set up system line calculation of fault model and collect line fault calculate mould
Type；Specially：
(1) based on the inverter failure Equivalent Model with low voltage crossing control strategy, to containing neutral point through resistance
The photovoltaic electric station grid connection system of ground connection sets up basic model；The three-phase output voltage and three-phase of photovoltaic DC-to-AC converter are defeated during including failure
Go out electric current；Electric current and voltage that the photovoltaic DC-to-AC converter defined according to instantaneous reactive power theory is exported；Three-phase instantaneous active power；
Three-phase instantaneous reactive power；In Voltage Drop, inverter is for the stabilization for the active reactive power for maintaining output of trying one's best, inversion
The active and reactive reference value of device output current reference value and any photovoltaic DC-to-AC converter.
(2) be directed to the photovoltaic electric station grid connection system containing Neutral Grounding through Resistance in Electrical two class circuits --- system line and
Collect the respective characteristic of circuit in standing, accordingly set up system line calculation of fault model and collect line fault computation model.
(3) when failure occurs on system line, then whole photovoltaic plant is equivalent to the power supply of a Large Copacity, and
The characteristic of voltage-controlled current source is presented, is modeled according to positive and negative zero-sequence network, wherein photovoltaic plant is by the positive negative zero of short circuit current flow
Order components are injected separately into positive and negative zero-sequence network.
(4) when failure occurs at photovoltaic station when collecting on circuit, it is impossible to whole photovoltaic station is equivalent into a power supply again,
Re-establish and collect line fault computation model；If trouble point is located at and collects wherein one section cable Z of lineCfOn.Do not break down
Collect line equivalent for controlled current source, that broken down collects that circuit is individually equivalent, and collection bus is electric to failure
Cable ZCfBetween inverter group be equivalent to a controlled current source, ZCfIt is equivalent to the inverter group collected between line end
One controlled current source, whole system equivalence is the network of power supply more than one, then system power supply and each several part impedance are converted
To collection bus side, it is modeled according to positive and negative zero-sequence network, wherein photovoltaic plant divides the positive and negative zero-sequence component of short circuit current flow
Positive and negative zero-sequence network is not injected.
A kind of point of the photovoltaic electric station grid connection fault model based on Neutral Grounding through Resistance in Electrical provided below for the present invention
The concrete application example of analysis method.
By taking large-sized photovoltaic station (50MW) grid-connected system of a typical Neutral Grounding through Resistance in Electrical as an example, network topology such as Fig. 1.
Photo-voltaic power supply is presented in controlled current source characteristic, engineering in failure, because each generator unit in same photovoltaic station is consistent
Property it is very strong, and determine photovoltaic power intensity of illumination and temperature it is basically identical in same photovoltaic station, it can be assumed that
All parameters of each generator unit are equal, each generator unit is consistent in the power that synchronization is sent.
Therefore, when failure occurs on 35kV system lines, whole photovoltaic plant can be equivalent to one big by we
The power supply of capacity.When occurring earth fault, the characteristic of voltage-controlled current source is presented in photovoltaic source, and photovoltaic DC-to-AC converter takes positive sequence control
Strategy, by the positive-sequence component injection network of short circuit current flow, as shown in Figure 2, it is established that the positive and negative zero-sequence network of system line failure
Model.
When failure occurs to collect on circuit in photovoltaic station, it is impossible to whole photovoltaic station is equivalent into a power supply again, needed
Re-establish and collect line fault computation model.If trouble point is located at and collects wherein one section cable Z of lineCfOn.4 not broken down
Bar collects controlled current source I of the line equivalent for a 40MW40S, break down that to collect circuit individually equivalent, 35kV converges
Collect bus to failure cable ZCfBetween m 1MW inverter group be equivalent to mMW controlled current source ImS, ZCfTo collecting line
N 1MW inverter group between the end of road is equivalent to nMW controlled current source InS, wherein m+n=10, whole system etc.
It is worth for the network of power supply more than one, then system power supply and each several part impedance are converted into 35kV sides, it is established that photovoltaic collects line
Positive and negative zero-sequence network model such as Fig. 5 of road failure.
System line calculation of fault model based on foregoing foundation, further carries out accident analysis；By system line failure
Connection in series-parallel merging is done in each branch impedance in positive and negative zero-sequence network topological diagram 2, obtains equivalent network Fig. 3 of positive and negative zero sequence.
When singlephase earth fault occurs for system line, with reference to singlephase earth fault boundary condition：I.e. the relation of the positive and negative residual voltage electric current of earth point, obtains system line single-phase earthing
Failure compound sequence network Fig. 4, and then loop current equation group is obtained by the loop method of analysis；
WhereinFor trouble point positive and negative residual voltage over the ground,For the positive and negative zero-sequence current of trouble point.
In formula (1), Ii：Loop i loop current；ZS35：35kV system positive sequence equivalent impedances；ZL351：M buses are to trouble point
Line impedance between K；ZT：Photovoltaic source Equivalent Transformer impedance；ES：35kV system phase voltages；Photo-voltaic power supply terminal voltage；Photovoltaic source fault current；Z∑0：Zero sequence synthetic impedance；P*And Q*The active and idle ginseng of inverter control during for fault traversing
Examine value.
In conjunction with foregoing inverter failure Equivalent Model, the non-linear solution of system line singlephase earth fault is set up
Equation group is as follows：
In formula (2), ZS35:35kV system positive sequence equivalent impedances；ZL351:M buses are to the line impedance between the K of trouble point；ZT:
Photovoltaic source Equivalent Transformer impedance；Z∑0:Zero sequence synthetic impedance；ES:35kV system phase voltages；Photo-voltaic power supply terminal voltage；
Photovoltaic source fault current；Trouble point zero-sequence current；
η is the capacity coefficient of inverter after failure, For photo-voltaic power supply terminal voltage positive sequence after failure
Component；ImaxFor inverter maximum allowed current, according to newest standards Imax=1.5In；Sn、UnAnd InFor inverter rated capacity,
Voltage and current；kqFor reactive power support coefficient；P*And Q*Inverter exports active and idle reference value during for failure；WithFor
Inverter exports active and idle reference value during normal operation.
Formula (2) is the equation group of system line singlephase earth fault, is hadFive unknown numbers, fx=
[f1f2f3f4f5]TFive equations, can be solved, but be due to the non-linear relation of equation, it is impossible to directly try to achieve analytic solutions, so
Convergence solution is tried to achieve with Newton-Laphson iteration construction iterated revision equation, realizes that singlephase earth fault is analyzed.
Likewise, collecting line fault computation model based on foregoing, accident analysis is further carried out；Circuit event will be collected
Hinder each branch impedance in positive and negative zero-sequence network topological diagram 5 and do connection in series-parallel merging, obtain equivalent network Fig. 6 of positive and negative zero sequence.
When collecting circuit generation singlephase earth fault in photovoltaic station, with reference to boundary condition：The relation of positive and negative zero-sequence current voltage at failure, whereinFor trouble point over the ground
Positive and negative residual voltage,For the positive and negative zero-sequence current of trouble point), i.e. the relation of the positive and negative residual voltage electric current of earth point,
Obtain collecting line single phase grounding failure compound sequence network Fig. 7, loop current equation group is obtained by the loop method of analysis；
In formula (3), Ii：Loop i loop current；ZS35：35kV system positive sequence equivalent impedances；ZL35：35kV line impedances；
ZT40：Non-faulting collects line photovoltaic source Equivalent Transformer impedance；ZTm,ZTn1：Failure collects line photovoltaic source Equivalent Transformer impedance；
ES：35kV system phase voltages；Non-faulting collects the equivalent photovoltaic source voltage terminal of line and fault current；Collect mother
Photovoltaic inversion equivalent source terminal voltage and fault current between line and trouble point；Trouble point to collect line end photovoltaic
Inversion equivalent source terminal voltage and fault current；Z∑0：Zero sequence synthetic impedance；Z∑2：Negative phase-sequence comprehensive impedance.
In conjunction with foregoing Photovoltaic Inverter failure Equivalent Model, collect line fault computation model and contain a system electricity
Source and three photo-voltaic power supplies, each photo-voltaic power supply have the current equation and active reactive equation of oneself, set up photovoltaic and collect line
The non-linear solution equation group of road singlephase earth fault is as follows：
In formula (4)~(7),Trouble point zero-sequence current；ZS35：35kV system positive sequence equivalent impedances；ZL35：35kV circuits
Impedance；ZT40：Non-faulting collects line photovoltaic source Equivalent Transformer impedance；ZTm,ZTn1：Failure collects the resistance of line photovoltaic source Equivalent Transformer
It is anti-；Zm:Cable positive-negative sequence impedance between collection bus and trouble point；ZCf1:The line impedance of failure cable；ES：35kV system phases
Voltage；
Collect line fault computation model and contain three photovoltaic current sources, each photovoltaic source have oneself current equation and
Active reactive equation：
Non-faulting collects the equivalent photovoltaic source voltage terminal of line and fault current；η40SFor the equivalent photovoltaic inversion electricity
The capacity coefficient in source, WithThe equivalent Photovoltaic Inverter output is active and idle during for failure
Reference value；WithInverter exports active and idle reference value during for normal operation.
Photovoltaic inversion equivalent source terminal voltage and fault current between collection bus and trouble point；ηmSFor this etc.
The capacity coefficient of Photovoltaic Inverter is imitated, WithEquivalent Photovoltaic Inverter output during for failure
Active and idle reference value；WithInverter exports active and idle reference value during for normal operation.
Trouble point to collect line end photovoltaic inversion equivalent source terminal voltage and fault current；ηnSIt is equivalent for this
The capacity coefficient of Photovoltaic Inverter, WithThere is the equivalent Photovoltaic Inverter output during for failure
Work(and idle reference value；WithInverter exports active and idle reference value during for normal operation.
Formula (4)~(7), have 13 equations and
13 unknown numbers, equally try to achieve convergence solution with Newton-Laphson iteration construction iterated revision equation, realize that photovoltaic collects line
Road singlephase earth fault analysis.
In order to draw the photovoltaic electric station grid connection failure protection scheme of perfect Neutral Grounding through Resistance in Electrical, it is necessary to which complete grinds
Study carefully in the case where neutral resistance Rg takes different resistances, system line and the different faults position for collecting circuit occur each
The characteristic of symmetrical and unbalanced fault is planted, and the mutual cooperation relation of protection 1 and protection 2 shown in Fig. 1 must be taken into full account.
So system line and the failed shorted phase current and sequence electric current that collect circuit under different situations need to be calculated respectively.Wherein, when event
When barrier is occurred on system line, collect the forward-order current that photo-voltaic power supply generation is flowed only through on circuit, without zero-sequence current.
Result of calculation based on example, can study this representative network 35kV system lines and photovoltaic collect circuit after
Electric protection scheme.
Claims (3)
1. the photovoltaic electric station grid connection line fault computation model of a kind of Neutral Grounding through Resistance in Electrical, it is characterised in that including following step
Suddenly：
(1) based on the inverter failure Equivalent Model with low voltage crossing control strategy, to containing Neutral Grounding through Resistance in Electrical
Photovoltaic electric station grid connection system be modeled；The three-phase output voltage of photovoltaic DC-to-AC converter and three-phase output current during including failure；
Electric current and voltage that the photovoltaic DC-to-AC converter defined according to instantaneous reactive power theory is exported；Three-phase instantaneous active power；Three-phase wink
When reactive power；In Voltage Drop, inverter is in order to maintain the stabilization of the active reactive power of output as far as possible, and inverter is exported
The active and reactive reference value of current reference value and any photovoltaic DC-to-AC converter；
(2) the photovoltaic electric station grid connection system network architecture to typical Neutral Grounding through Resistance in Electrical is studied, and learns grid-connected event
Barrier can be divided into two types, and the first failure occurs on system line, and second of failure occurs to collect line in photovoltaic station
Lu Shang；For the characteristic of this two classes line fault, calculation of fault model is set up respectively；
(3) when failure occurs on system line, whole photovoltaic plant can be equivalent to the power supply of a Large Copacity, power supply
Voltage-controlled current source characteristic is presented, positive and negative zero-sequence network model is set up respectively, the photovoltaic current source that positive sequence is controlled is taken containing only positive sequence
Component, injects positive sequence network, negative phase-sequence and zero-sequence network do not contain power supply；
(4), will when failure occurs to collect on circuit in photovoltaic station, it is impossible to whole photovoltaic station is equivalent into a power supply again
Non- failure collects line and failure collects line and distinguishes equivalent；Non- failure collects line and is equivalent to a controlled current source, and failure collects line
Disconnected from trouble point and be equivalent to two power supplys, if trouble point is located at cable ZCfOn, then collection bus is to failure cable ZCfBetween
Inverter group is equivalent to a controlled current source, ZCfAnother controlled electricity is equivalent to the inverter group collected between line end
Stream source；Whole system equivalence is the network of power supply more than one, and positive and negative zero-sequence network model, each photovoltaic current source are set up respectively
Respective positive sequence short circuit current flow is injected in positive sequence network, negative phase-sequence and zero-sequence network do not contain power supply.
2. a kind of failure analysis methods of the photovoltaic electric station grid connection system of Neutral Grounding through Resistance in Electrical, it is characterised in that：Based on power
Profit requires the line fault computation model of 1 foundation, photo-voltaic power supply is handled as controlled source, with reference to the side of various fault types
Boundary's condition, obtains fault network nonlinear multivariable equation group, is then asked with Newton-Laphson iteration construction iterated revision equation
Convergence solution is obtained, accident analysis is realized.By taking typical photovoltaic electric station grid connection as an example, such as Fig. 1 networks：
(1) when failure occurs on system line, there is positive and negative zero-sequence network such as Fig. 2, then connection in series-parallel is done into each branch impedances of Fig. 2
Merge, obtain equivalent network such as Fig. 3 of positive and negative zero sequence；
By taking singlephase earth fault as an example, according to boundary condition, compound sequence network Fig. 4 is obtained, loop current equation group is obtained；
Simultaneous loop current equation group and Photovoltaic Inverter model equation obtain the solution side of system line singlephase earth fault
Journey group；Solving equation group has five unknown numbers and five equations, can solve, but be due to the non-linear relation of equation, it is impossible to
Analytic solutions directly are tried to achieve, so trying to achieve convergence solution with Newton-Laphson iteration construction iterated revision equation, accident analysis are realized；
(2) when failure occurs to collect on circuit in photovoltaic station, there is positive and negative zero-sequence network such as Fig. 5, then each branch impedance is done
Connection in series-parallel merges, and obtains equivalent network such as Fig. 6 of positive and negative zero sequence；
By taking singlephase earth fault as an example, combination failure boundary condition obtains compound sequence network Fig. 7, can obtain loop current equation group；
Collect line fault computation model and contain three photovoltaic current sources, each photovoltaic source has the current equation and active of oneself
Idle equation, by these equation groups and loop current equation group simultaneous, obtains the equation that photovoltaic collects line single phase grounding failure
Group, has 13 equations and 13 unknown numbers, can solve, and equally constructs iterated revision side with Newton-Laphson iteration
Journey tries to achieve convergence solution, realizes accident analysis.
3. the failure analysis methods of the photovoltaic electric station grid connection system using the Neutral Grounding through Resistance in Electrical described in claim 2, point
Analyse the characteristic that various symmetrical and unbalanced faults occur for circuit different faults position, it is characterised in that take into full account shown in Fig. 1
Collect the matching relationship between route protection and system line protection, respectively computing system circuit and the failed shorted for collecting circuit
Phase current and sequence electric current, so as to adjusting for relay protection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710508619.7A CN107272645B (en) | 2017-06-28 | 2017-06-28 | The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710508619.7A CN107272645B (en) | 2017-06-28 | 2017-06-28 | The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107272645A true CN107272645A (en) | 2017-10-20 |
| CN107272645B CN107272645B (en) | 2019-08-02 |
Family
ID=60071049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710508619.7A Active CN107272645B (en) | 2017-06-28 | 2017-06-28 | The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107272645B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110018400A (en) * | 2019-05-20 | 2019-07-16 | 国网甘肃省电力公司天水供电公司 | A kind of DC power distribution line Fault Locating Method |
| CN110162889A (en) * | 2019-05-24 | 2019-08-23 | 南方电网科学研究院有限责任公司 | It is a kind of it is sagging control inverter fault current determine method |
| CN110412377A (en) * | 2019-05-14 | 2019-11-05 | 深圳市禾望电气股份有限公司 | A kind of voltage failure of static reactive generator passes through test method |
| CN111384725A (en) * | 2018-12-29 | 2020-07-07 | 中国电力科学研究院有限公司 | Short-circuit current calculation method and system for new energy power station |
| CN111551817A (en) * | 2020-03-31 | 2020-08-18 | 国网江西省电力有限公司电力科学研究院 | Single-phase earth fault current calculation method for resonance earth distribution network |
| CN114725911A (en) * | 2022-04-06 | 2022-07-08 | 合肥工业大学 | Estimation method for neutral point grounding resistance of transformer of wind power plant collection station system |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101055994A (en) * | 2007-03-09 | 2007-10-17 | 中国科学院电工研究所 | Integrated control method for the combined network power generation and grid power active filtering |
| CN102611138A (en) * | 2012-03-20 | 2012-07-25 | 湖南大学 | Delay-free single-phase photovoltaic synchronization power adjusting method |
| CN102664407A (en) * | 2012-05-04 | 2012-09-12 | 甘肃省电力设计院 | Method and system for designing boosting transformer of new energy electric field |
| CN102721883A (en) * | 2012-06-15 | 2012-10-10 | 中国电力科学研究院 | Detecting device for low voltage ride-through of grid-connected photovoltaic inverter |
| CN103308821A (en) * | 2013-05-13 | 2013-09-18 | 沈阳农业大学 | Intermittent arcing ground-fault line selection method based on improved phase locked loop |
| CN103529335A (en) * | 2013-10-30 | 2014-01-22 | 国家电网公司 | Low voltage ride through detection device for grid connection photovoltaic inverter |
| WO2015106704A1 (en) * | 2014-01-20 | 2015-07-23 | 袁欣 | Plug-in outer-lead photovoltaic assembly junction box and solar photovoltaic assembly string |
| CN105552861A (en) * | 2015-12-29 | 2016-05-04 | 河南省电力勘测设计院 | Adaptive current protection algorithm |
-
2017
- 2017-06-28 CN CN201710508619.7A patent/CN107272645B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101055994A (en) * | 2007-03-09 | 2007-10-17 | 中国科学院电工研究所 | Integrated control method for the combined network power generation and grid power active filtering |
| CN102611138A (en) * | 2012-03-20 | 2012-07-25 | 湖南大学 | Delay-free single-phase photovoltaic synchronization power adjusting method |
| CN102664407A (en) * | 2012-05-04 | 2012-09-12 | 甘肃省电力设计院 | Method and system for designing boosting transformer of new energy electric field |
| CN102721883A (en) * | 2012-06-15 | 2012-10-10 | 中国电力科学研究院 | Detecting device for low voltage ride-through of grid-connected photovoltaic inverter |
| CN103308821A (en) * | 2013-05-13 | 2013-09-18 | 沈阳农业大学 | Intermittent arcing ground-fault line selection method based on improved phase locked loop |
| CN103529335A (en) * | 2013-10-30 | 2014-01-22 | 国家电网公司 | Low voltage ride through detection device for grid connection photovoltaic inverter |
| WO2015106704A1 (en) * | 2014-01-20 | 2015-07-23 | 袁欣 | Plug-in outer-lead photovoltaic assembly junction box and solar photovoltaic assembly string |
| CN105552861A (en) * | 2015-12-29 | 2016-05-04 | 河南省电力勘测设计院 | Adaptive current protection algorithm |
Non-Patent Citations (1)
| Title |
|---|
| 吴兴全，吴丽等: "电阻接地的并网光伏电站零序电流工程实用算法", 《电力系统保护与控制》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111384725A (en) * | 2018-12-29 | 2020-07-07 | 中国电力科学研究院有限公司 | Short-circuit current calculation method and system for new energy power station |
| CN110412377A (en) * | 2019-05-14 | 2019-11-05 | 深圳市禾望电气股份有限公司 | A kind of voltage failure of static reactive generator passes through test method |
| CN110018400A (en) * | 2019-05-20 | 2019-07-16 | 国网甘肃省电力公司天水供电公司 | A kind of DC power distribution line Fault Locating Method |
| CN110018400B (en) * | 2019-05-20 | 2021-10-01 | 国网甘肃省电力公司天水供电公司 | Direct-current distribution line fault positioning method |
| CN110162889A (en) * | 2019-05-24 | 2019-08-23 | 南方电网科学研究院有限责任公司 | It is a kind of it is sagging control inverter fault current determine method |
| CN110162889B (en) * | 2019-05-24 | 2022-12-06 | 南方电网科学研究院有限责任公司 | Method for determining fault current of droop control inverter |
| CN111551817A (en) * | 2020-03-31 | 2020-08-18 | 国网江西省电力有限公司电力科学研究院 | Single-phase earth fault current calculation method for resonance earth distribution network |
| CN114725911A (en) * | 2022-04-06 | 2022-07-08 | 合肥工业大学 | Estimation method for neutral point grounding resistance of transformer of wind power plant collection station system |
| CN114725911B (en) * | 2022-04-06 | 2024-03-26 | 合肥工业大学 | Estimation method for neutral point grounding resistance of transformer of wind farm collecting station system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107272645B (en) | 2019-08-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107272645B (en) | The photovoltaic electric station grid connection fault model and analysis method of Neutral Grounding through Resistance in Electrical | |
| CN103887810B (en) | Straight-flow system based on short-circuit ratio dynamic tracking continues phase conversion failure judgment method | |
| CN104009452B (en) | A kind of protection scheme for direct-flow distribution system short trouble | |
| CN103605829A (en) | Equivalent model method for performing electromagnetic transient simulation on alternating current/direct current hybrid power grid | |
| CN103269069A (en) | Method for reconstructing low-voltage power transmission system | |
| Li et al. | Research on power flow calculation method of true bipolar VSC-HVDC grids with different operation modes and control strategies | |
| CN102982230A (en) | Short circuit current exceeding auxiliary decision method based on node impedance sensitivity | |
| CN108075476A (en) | A kind of security constraint optimal load flow method based on power flow transfer relation | |
| CN105162099A (en) | Operational curved surface method for determining asymmetric short-circuit current of distributed generation access power grid | |
| CN110336327A (en) | Consider the power distribution network short circuit current acquisition methods of distributed photovoltaic low voltage crossing | |
| CN107292481A (en) | A kind of power network key node appraisal procedure based on pitch point importance | |
| CN111211574A (en) | Method for calculating bipolar fault current on direct current side of multi-terminal direct current power grid based on half-bridge type MMC | |
| CN105277773A (en) | Method for completely calculating grounding short-circuit current of transformation station | |
| CN106505608A (en) | Meter and the distributed power source calculation of penetration level method of capacity of short circuit constraint | |
| Martínez-Parrales et al. | A VSC-based model for power flow assessment of multi-terminal VSC-HVDC transmission systems | |
| Gopalan et al. | Fault analysis of an islanded multi-microgrid | |
| Li et al. | Analysis and calculation method for multiple faults in low-resistance grounded systems with inverter-interfaced distributed generators based on a PQ control strategy | |
| Tristiu et al. | A new and efficient algorithm for short-circuit calculation in distribution networks with distributed generation | |
| CN104882904B (en) | A kind of anti-isolated island guard method of new photovoltaic plant passive type | |
| CN103560494B (en) | The short circuit current acquisition methods that distribution protection is adjusted | |
| CN107196307B (en) | A kind of method that electric network active trend is quickly estimated after transformer fault | |
| CN102064547A (en) | Method for rapidly solving static stability limit power of single power transmission channel | |
| CN106253248B (en) | Distributed generation resource based on interval arithmetic and conventional power plants short-circuit current calculation method | |
| CN115566632A (en) | Ring main unit passive protection self-adaptive setting system and method thereof | |
| Hashemi et al. | Impact of distributed generation on unbalanced distribution networks |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |