CN106058830B - A kind of current protection system of power distribution network containing DG and method - Google Patents
A kind of current protection system of power distribution network containing DG and method Download PDFInfo
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- CN106058830B CN106058830B CN201610597547.3A CN201610597547A CN106058830B CN 106058830 B CN106058830 B CN 106058830B CN 201610597547 A CN201610597547 A CN 201610597547A CN 106058830 B CN106058830 B CN 106058830B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
Abstract
The present invention relates to a kind of current protection system of power distribution network containing DG and methods, the described method comprises the following steps：The power distribution network supplemental characteristic of fault information acquisition module acquisition secondary protector installation place, and it is uploaded to adaptive Current Protection module；The supplemental characteristic that adaptive Current Protection module uploads information acquisition module is handled, and is identified fault message according to deliberate action criterion and is obtained corresponding decision as a result, and the result of decision is sent to protection act module；Protection act module sends trip signal to corresponding breaker, drives trip operation according to the result of decision.The protection system and method has considered the fault transient characteristic of full inverse type DG and half inverse type DG, forms unified adaptive direction current protection criterion, adaptable from DG patterns affects；Reliability is higher；When reply Voltage Drop and low voltage crossing, can correctly it act, sensitivity is higher.
Description
Technical field
The present invention relates to technical field of relay protection more particularly to a kind of current protection system of power distribution network containing DG and methods.
Background technology
Traditional distribution network is usually radial, supplies one or several, downstream distribution line by single supply, passes
The distribution network protection of system is also to carry out adjusting design according to single direction of tide.To meet ever-increasing workload demand, and have
Effect is to fossil energy crisis, and with the continuous propulsion of new energy power generation technology, DG is directly accessed to distribution network on the spot to be become
First choice, the access capacity of Distributed Generation in Distribution System is growing, is gradually sent out with the conventional electrical distribution net of radial pattern open loop operation
Open up the active distribution network for the power supply of multiterminal power supply.The access of DG can improve power quality, improve power supply reliability and reduce circuit
Loss, but a series of problem also is brought for the protection control of distribution simultaneously, distribution power flow distribution is widely varied,
And the method for operation and capacity of short circuit are difficult to determine.Traditional directionless overcurrent protection based on fixed action current, it is difficult to just
Really reflect a large amount of distributed generation resources (Distributed Generation, DG) access after power distribution network fault condition, exist compared with
High malfunction, the risk of tripping.Therefore, research is suitable for the power distribution network current protection of distributed generation resource access, to ensureing distribution
Net safe and stable operation is of great significance.
At present, some experts and scholar have made intensive studies to containing DG power distribution network current protections, mainly include：
1st, according to DG maximums and minimum capacity setting current fast tripping protection.This method can avoid the occurrence of tripping,
But in the case where DG capacity is widely varied, there are the possibility of malfunction.
2nd, according to the current method of operation and the setting valve of the online calculating action electric current of fault type.This method is adapted to
The variation of system operation mode after DG accesses, but a degree of simplification has been carried out to DG fault transients model.
3rd, the detailed model based on full inverse type DG derives self-adaptive current fast tripping protection tuning formulae.This method does not have
There is the influence for considering other types DG to failure.
In addition, without delay protection tripping caused by solution low and medium voltage distribution network Voltage Drop in prior art.
Therefore, it is necessary to a kind of current protection system of power distribution network containing DG and method, for solving existing distribution protection containing DG
Scheme is difficult to the problem of correct response fault condition, false protection and tripping.
The content of the invention
In view of above-mentioned analysis, the present invention is intended to provide a kind of current protection system of power distribution network containing DG and method, to solve
The problem of certainly existing scheme of distribution protection containing DG is difficult to correct response fault condition, false protection and tripping.
The purpose of the present invention is mainly achieved through the following technical solutions：
A kind of current protection method of power distribution network containing DG, which is characterized in that comprise the following steps：
Step S1, the power distribution network supplemental characteristic of fault information acquisition module acquisition secondary protector installation place, and upload
To adaptive Current Protection module；
Step S2, the supplemental characteristic that adaptive Current Protection module uploads information acquisition module is handled, according to pre-
If operating criterion identifies fault message and obtains corresponding decision as a result, and the result of decision is sent to protection act module；
Step S3, protection act module sends trip signal, driving is jumped according to the result of decision to corresponding breaker
Lock acts.
The power distribution network supplemental characteristic includes：
Protect installation place fault current Imf, I section of action current I of self-adaptive currentZDZ,Ⅰ, protect back side equivalence potentialIt protects
Backpiece side equivalent impedance Ze, line impedance ZL, peak response angleProtect installation place positive sequence false voltage steady-state componentInstallation place is protected to be free of the positive sequence fault current steady-state component of DG mutation currents
Protect installation place measurement voltageProtect installation place false voltage Sudden Changing RateProtect installation place fault current
Figure variable
II section of action current I of self-adaptive currentZDZ,Ⅱ, this line impedance ZsL, subordinate line impedance ZnL, I section of guarantor of subordinate's circuit
Protect range betanL, braning factor Kb。
The operating criterion is adaptive direction current protection criterion under different faults type, including：
The operating criterion of I section of self-adaptive current under the operating criterion of I section of self-adaptive current, three-phase shortcircuit under line to line fault,
Under line to line fault under the operating criterion and three-phase shortcircuit of II section of self-adaptive current II section of self-adaptive current operating criterion.
The adaptive direction current protection criterion is obtained by following steps：
The fault transient characteristic and failure equivalence method of sub-step S21, analysis different type DG, computing system short circuit electricity
Component contained by stream obtains the relation between three phase components of short circuit current flow；
Sub-step S22, according to failure boundary condition, obtain system failure steady-state component, the measurement of join protection installation place
Voltage and measurement electric current, calculate threshold voltages and the equivalent impedances such as protection back side；
Adaptive direction current protection criterion under sub-step S23, construction different faults type.
The criterion has fault type judgment mechanism in itself, as long as meeting criterion, you can clear failure type.
The step S2 further comprises：
If the gathered data continuously meets the operating criterion of I section of self-adaptive current, corresponding decision is obtained as a result, and will
The result of decision is sent to protection act module, and the result of decision is I sections of actions of protection；
If the gathered data continuously meets the operating criterion of II section of self-adaptive current, accordingly determined after the Δ t that is delayed
Plan as a result, and the result of decision is sent to protection act module, the result of decision is II section of action of protection.
A kind of current protection system of power distribution network containing DG, the system comprises fault information acquisition module, self-adaptive currents to protect
Module and protection act module are protected, for performing the above method, wherein,
The fault information acquisition module is used to gather the power distribution network supplemental characteristic of secondary protector installation place, and uploads
To adaptive Current Protection module；
The adaptive Current Protection module is used for the power distribution network supplemental characteristic that handling failure information acquisition module uploads, root
Fault message is identified according to deliberate action criterion and obtains corresponding decision as a result, the result of decision is sent to protection act module；
The protection act module is used to, according to the result of decision, instruct to breaker sending action, indicates breaker
It trips or is failure to actuate.
The deliberate action criterion is adaptive direction current protection criterion under different faults type, including：
The operating criterion of I section of self-adaptive current under the operating criterion of I section of self-adaptive current, three-phase shortcircuit under line to line fault,
Under line to line fault under the operating criterion and three-phase shortcircuit of II section of self-adaptive current II section of self-adaptive current operating criterion.
The criterion has fault type judgment mechanism in itself, as long as meeting one of criterion, you can clear failure type, phase
It should protect i.e. actionable.
The adaptive direction current protection criterion is obtained especially by following steps：
Analyze the fault transient characteristic and failure equivalence method of different type DG, contained point of computing system short circuit current flow
Amount, and disclose the relation between three phase components of short circuit current flow；
According to failure boundary condition, system failure steady-state component is obtained, measurement voltage and survey in conjunction with protection installation place
Electric current is measured, calculates threshold voltages and the equivalent impedances such as protection back side；
Construct adaptive direction current protection criterion under different faults type.
The present invention has the beneficial effect that：
The protection system and method has considered the fault transient characteristic of full inverse type DG and half inverse type DG, is formed
Unified adaptive direction current protection criterion, it is adaptable from DG patterns affects；In different running method and failure
Under type, by measurement electric current and voltage according to different criterions in line computation setting valve, reliability is higher；Adaptive electric current in limited time
Fast tripping protection can be acted correctly, sensitivity is higher when reply Voltage Drop and low voltage crossing.
Other features and advantages of the present invention will illustrate in the following description, also, partial become from specification
It obtains it is clear that being understood by implementing the present invention.The purpose of the present invention and other advantages can be by the explanations write
Specifically noted structure is realized and obtained in book, claims and attached drawing.
Description of the drawings
Attached drawing is only used for showing the purpose of specific embodiment, and is not considered as limitation of the present invention, in entire attached drawing
In, identical reference symbol represents identical component.
Fig. 1 is a kind of current protection analogue system structure chart of power distribution network containing DG；
Fig. 2 is simple distribution system equivalent circuit diagram；
Fig. 3 a are distribution system normal condition Equivalent Network circuit diagram；
Fig. 3 b are distribution system failure stable state complementary network equivalent circuit diagram；
Fig. 3 c are distribution system fault transient complementary network equivalent circuit diagram；
Fig. 4 is influence schematic diagram of subordinate's line fault inferior division coefficient to current protection；
Fig. 5 is a kind of method flow diagram of the current protection method of power distribution network containing DG.
Specific embodiment
The preferred embodiment of the present invention is specifically described below in conjunction with the accompanying drawings, wherein, attached drawing forms the application part, and
It is used to illustrate the principle of the present invention together with embodiments of the present invention.
A specific embodiment according to the present invention discloses a kind of current protection system of power distribution network containing DG and method, such as
Shown in Fig. 1, the system comprises fault information acquisition module, adaptive Current Protection module and protection act module, wherein,
The fault information acquisition module is used to gather the power distribution network supplemental characteristic of secondary protector installation place, and uploads
To adaptive Current Protection module；
Specifically, the fault information acquisition module includes current transformer, the voltage transformer of protection installation place, utilizes
The distribution such as measurement impedance, voltage and current steady-state component, voltage and current Sudden Changing Rate are calculated in the measured value of above two mutual inductor
Network parameters data.The supplemental characteristic can pass through the communication links such as optical fiber, cable to adaptive Current Protection module.
The adaptive Current Protection module is used for the power distribution network supplemental characteristic that handling failure information acquisition module uploads, root
Fault message is identified according to deliberate action criterion and obtains corresponding decision as a result, the result of decision is sent to protection act module；
Specifically, the deliberate action criterion is adaptive direction current protection criterion under different faults type, including：
The operating criterion of I section of self-adaptive current under the operating criterion of I section of self-adaptive current, three-phase shortcircuit under line to line fault,
Under line to line fault under the operating criterion and three-phase shortcircuit of II section of self-adaptive current II section of self-adaptive current operating criterion.
Above-mentioned criterion has fault type judgment mechanism in itself, as long as meeting one of criterion, you can clear failure type, phase
It should protect i.e. actionable.
Specifically, the adaptive direction current protection criterion is obtained especially by following steps：
Analyze the fault transient characteristic and failure equivalence method of different type DG, contained point of computing system short circuit current flow
Amount, and disclose the relation between three phase components of short circuit current flow；
According to failure boundary condition, system failure steady-state component is obtained, measurement voltage and survey in conjunction with protection installation place
Electric current is measured, calculates threshold voltages and the equivalent impedances such as protection back side；
Construct adaptive direction current protection criterion under different faults type.
The protection act module is used to, according to the result of decision, instruct to breaker sending action, indicates breaker
It trips or is failure to actuate.
Another specific embodiment according to the present invention discloses one kind by the above-mentioned current protection system of power distribution network containing DG institute
The current protection method of power distribution network containing DG performed, as shown in Figure 5, which is characterized in that the described method comprises the following steps：
Step S1, the power distribution network supplemental characteristic of fault information acquisition module acquisition secondary protector installation place, and upload
To adaptive Current Protection module；Specifically,
The fault information acquisition module includes current transformer, the voltage transformer of protection installation place, passes through above-mentioned two
Kind mutual inductor obtains power distribution network supplemental characteristic.
Wherein, current transformer be exactly by the current transformation under high current or high voltage into low-voltage normalized current (5A or
Electric appliance 1A)；High voltage is exactly transformed into the electric appliance of normal voltage (100V) by voltage transformer；By detecting current transformer
The electric current that quadratic transformation comes out, so that it may which knowing in circuit has no current to flow through, and size of current is how many, if under normal circumstances
Operation.The voltage for converting out by detecting voltage transformer secondary, so that it may know whether there is voltage in circuit, whether just voltage
Often.
The supplemental characteristic can pass through the communication links such as optical fiber, cable to adaptive Current Protection module.
The power distribution network supplemental characteristic includes：
Protect installation place fault current Imf, I section of action current I of self-adaptive currentZDZ,Ⅰ, protect back side equivalence potentialIt protects
Backpiece side equivalent impedance Ze, line impedance ZL, peak response angleProtect installation place positive sequence false voltage steady-state componentInstallation place is protected to be free of the positive sequence fault current steady-state component of DG mutation currents
Protect installation place measurement voltageProtect installation place false voltage Sudden Changing RateProtect installation place fault current
Figure variable
II section of action current I of self-adaptive currentZDZ,Ⅱ, this line impedance ZsL, subordinate line impedance ZnL, I section of guarantor of subordinate's circuit
Protect range betanL, braning factor Kb。
Wherein, peak response angleBraning factor Kb, I section of action current I of self-adaptive currentZDZ,Ⅰ, self-adaptive current
II section of action current IZDZ,ⅡIt is setting valve, other parameter is measured value.
Step S2, the supplemental characteristic that adaptive Current Protection module uploads information acquisition module is handled, according to pre-
If operating criterion identifies fault message and obtains corresponding decision as a result, and the result of decision is sent to protection act module；
Specifically, operating criterion described in step S2 is adaptive direction current protection criterion under different faults type, is wrapped
It includes：
The operating criterion of I section of self-adaptive current under the operating criterion of I section of self-adaptive current, three-phase shortcircuit under line to line fault,
Under line to line fault under the operating criterion and three-phase shortcircuit of II section of self-adaptive current II section of self-adaptive current operating criterion.
Above-mentioned criterion has fault type judgment mechanism in itself, as long as meeting one of following criterions, you can clear failure class
Type, corresponding protection is i.e. actionable, specifically：
(1) operating criterion of I section of self-adaptive current is under line to line fault：
In formula, ImfTo protect installation place fault current, IZDZ,ⅠFor I section of action current of self-adaptive current, KrelTake 1.2, KdIt takes To protect back side equivalence potential, ZeTo protect back side equivalent impedance, ZLFor line impedance.For peak response angle,To protect installation place positive sequence false voltage steady-state component,The positive sequence failure of DG mutation currents is free of for protection installation place
Electric current steady-state component.
(2) operating criterion of I section of self-adaptive current is under three-phase shortcircuit：
In formula, ImfTo protect installation place fault current, IZDZ,ⅠFor I section of action current of self-adaptive current, KrelTake 1.2,
Voltage, Z are measured for protection installation placeLFor line impedance.For peak response angle,To protect installation place failure
Sudden Changing Rate.
(3) operating criterion of II section of self-adaptive current is under line to line fault：
In formula, ImfTo protect installation place fault current, IZDZ,ⅡFor II section of action current of self-adaptive current, KrelTake 1.2, Kd
It takes To protect back side equivalence potential, ZeTo protect back side equivalent impedance, ZsLFor this line impedance, ZnLFor subordinate's circuit
Impedance, βnLFor I section of protection domain of subordinate's circuit, KbFor braning factor.For peak response angle,For protection installation place just
Sequence false voltage steady-state component,The positive sequence fault current steady-state component of DG mutation currents is free of for protection installation place.
(4) operating criterion of II section of self-adaptive current is under three-phase shortcircuit：
In formula, ImfTo protect installation place fault current, IZDZ,ⅡFor II section of action current of self-adaptive current, KrelTake 1.2,
To protect the measurement voltage of installation place, ZeTo protect back side equivalent impedance, ZsLFor this line impedance, ZnLFor subordinate's line impedance,
βnLFor I section of protection domain of subordinate's circuit, KbFor braning factor.For peak response angle,To protect installation place
Failure Sudden Changing Rate.
The adaptive direction current protection criterion is obtained especially by following steps：
The fault transient characteristic and failure equivalence method of sub-step S21, analysis different type DG, computing system short circuit electricity
Component contained by stream, and disclose the relation between three phase components of short circuit current flow；
Sub-step S22, according to failure boundary condition, system failure steady-state component is obtained, in conjunction with the survey of protection installation place
Voltage and measurement electric current are measured, calculates threshold voltages and the equivalent impedances such as protection back side；
Adaptive direction current protection criterion under sub-step S23, construction different faults type.
By taking Fig. 2 and simple distribution system shown in Fig. 3 as an example, illustrate I section of self-adaptive current in the case of construction line to line fault
The detailed process of operating criterion is as follows：
Sub-step S21, analysis fault transient characteristic and failure equivalence method, component contained by computing system short circuit current flow,
Obtain the relation between three phase components of short circuit current flow；
The A phase short circuit current flow instantaneous values of trouble point K are in Fig. 3：
iKA=iA,l+iA,f+ΔiA,FIDG+iA,dt+iA,ct (1)
In formula, iA,lFor load current component, iA,fFor trouble point additional supplyThe failure steady-state component of offer, Δ
iA,FIDGForThe failure steady-state component of offer, iA,dt、iA,ctRespectively DFIG (Double-fed Induction
Generator, doubly fed induction generator) provide direct current transient state component and industrial frequency AC transient state component.
Using fast Fourier algorithm, the direct current transient state component i that DFIG in formula (1) short circuit currents is providedA,dtRemoval
And by industrial frequency AC transient state component iA,ctAfter regarding load fluctuation amount as, short circuit current flow is the sinusoidal quantity of frequency 50Hz, by phasor
Method analyzes it, and obtains the electric phasor of short circuit of trouble point ABC three-phases：
By FIDG (Full Inversion Distributed Generation, full inverse distributed power unsteady flow
Device) influence of three-phase equilibrium control strategy,Three-phase symmetrical.
Sub-step S22, according to failure boundary condition, system failure steady-state component is obtained, in conjunction with the survey of protection installation place
Voltage and measurement electric current are measured, calculates threshold voltages and the equivalent impedances such as protection back side；
If the t=t0 moment, BC line to line fault occurs for K points in Fig. 3, then the boundary condition of trouble point is：Due to matching somebody with somebody
Electric system is earth-free, thenBeing converted to each order components has：
If the positive and negative sequence impedance of system is equal, then installation place each order relation of failure steady-state component is protected to be：
In formula,Respectively protect the installation place positive and negative sequence fault current stable state without DG mutation currents point
Amount, hereinafter referred to as fault current steady-state component,Respectively protect the positive and negative sequence false voltage stable state in installation place
Component.
It is identical with component contained by current in the short in view of component contained by protection installation place measurement electric current, therefore have：
In formula,Respectively protect installation place ABC three-phases measurement electric current； Respectively protect
Protect installation place three-phase load electric current；Respectively protection installation place FIDG mutation currents source carries
The three-phase fault electric current steady-state component of confession； For trouble point additional supplyThe three-phase fault stable state of offer
Component.
Protecting installation place load current and FIDG mutation currents, there are three-phase symmetrical relations：
Simultaneous formula (16)-(18) can must protect the positive and negative sequence fault current steady-state component in installation place to be：
The positive and negative sequence false voltage stable state in installation place can must be protected according to the linear relationship of false voltage, electric current steady-state component
Component is：
In formula,Respectively protect installation place ABC three-phases measurement voltage.
Above-mentioned derivation eliminates the influence of FIDG failures mutation current and DFIG transient currents, i.e. fault sequence component net
In network, protection back side no longer contains equivalent voltage source, therefore back side equivalent impedance is protected to be represented by：
Similarly, equivalent impedance can be also calculated by negative sequence component, recycles protection voltage and Current calculation protection back side
Equivalent potential：
Simultaneous formula (10) and (11) can be obtained under line to line fault, and I section of action current tuning formulae of self-adaptive current is：
In formula, Kd takesKrel is to take 1.2.
Sub-step S23, construction adaptive direction current protection criterion.
According to three short circuit current and line to line fault current relationship, as circuit α ZLWhen line to line fault occurs for place, wherein, α ZL
Line impedance of the protection installation place at failure is represented, also reflects circuit distance of the protection installation place at failure；Protection peace
Fault current size is at dress：
Make Imf=IZDZ,Ⅰ, α can be calculated to obtain<1.If ZeWith ZLImpedance angle is equal, can be in the hope of the expression formula β of α：
As abort situation α ＜ β, fault current is more than I section of setting valve of self-adaptive current, and protection will action：
As abort situation α ＞ β, fault current is less than I section of setting valve of self-adaptive current, and protection is failure to actuate：
From formula (15) and (16), I section of protection domain in line to line fault of β, that is, self-adaptive current, β ＜ 1 meet electricity
I section of protection domain of stream is less than the requirement of total track length.Furthermore β can adaptively adjust safety factor according to formula (14), meet simultaneously
The sensitivity and selectivity of protection require.
It is available since short dot is directed toward in the steady-state current direction that trouble point additional supply providesWithForm work(
Rate direction criterion, when avoiding protection upstream failure, downstream DG causes protection negative direction malfunction, the operation equation of power direction criterion
For：
In formula,For peak response angle.
In conclusion the operating criterion of I section of self-adaptive current is under line to line fault：
If the gathered data continuously meets the operating criterion of I section of self-adaptive current, corresponding decision is obtained as a result, and will
The result of decision is sent to protection act module, and the result of decision is I sections of actions of protection.
The detailed process of I section of operating criterion of self-adaptive current is as follows in the case of construction three-phase shortcircuit：
When metallicity three-phase shortcircuit occurs for system, the measurement voltage of route protection installation place where short dot and measurement electricity
Stream meets：
In formula,Respectively protect installation place measurement voltage, measurement electric current.
To ensure I section of selectivity of electric current, I section of setting valve of self-adaptive current is under three-phase shortcircuit：
Protection domain such as formula (22) is obtained according to formula (19), protection maximum magnitude also can be adaptively adjusted under three-phase shortcircuit
Size.
β=1/Krel (22)
The operation equation of power direction criterion is：
In formula,To protect installation place failure Sudden Changing Rate.
During three-phase shortcircuit, the short circuit current flow for flowing through protection is symmetrical, it is difficult to calculate failure stable state according to trouble point boundary condition
Component, therefore solved using the Sudden Changing Rate method of traditional adaptive Current Protection
The operating criterion of I section of self-adaptive current is under three-phase shortcircuit：
If the gathered data continuously meets the operating criterion of I section of self-adaptive current, corresponding decision is obtained as a result, and will
The result of decision is sent to protection act module, and the result of decision is I sections of actions of protection.
I section of actuating range is protected to ensure that II section of protection domain is no more than subordinate, the setting valve that II section of self-adaptive current is：
Under line to line fault：
Under three-phase shortcircuit：
In formula, ZsLFor this line impedance；ZnLFor subordinate's line impedance；βnLFor I section of protection domain of subordinate's circuit, by formula
(15) calculated with formula (22)；KbFor braning factor.
Voltage Drop causes II section of setting valve closer to load current, to still need to realize that failure is determined with reference to power direction criterion
Position.
The operating criterion of II section of self-adaptive current protection is：
Three-phase shortcircuit：
Line to line fault：
If the gathered data continuously meets the operating criterion of II section of self-adaptive current, accordingly determined after the Δ t that is delayed
Plan as a result, and the result of decision is sent to protection act module, the result of decision is II section of action of protection.
Illustrate the calculating of braning factor in II section of operating criterion of self-adaptive current below：
To ensure that II section of self-adaptive current can cover this total track length, maximum branch coefficient is calculated using DG rated capacities,
DG increasing-aid currents is avoided to cause relay fail.Protection scheme utilizes boundary condition and DG mutation currents source condition of three-phase balance, pushes away
The failure steady-state component without mutation power supply, therefore the equal voltage available sources of DFIG and FIDG and impedance series equivalent approach are led, before failure
Voltage source size is constant afterwards.
Influence of the braning factor to II section of self-adaptive current can be represented by Fig. 4 during subordinate's line short.As shown in Figure 4, protect
Shield S1 is helped increasing to be influenced by DFIG and FIDG, and current value is less than electric current at protection S2, and braning factor can be calculated by formula (29).To calculate
Maximum branch coefficient, system impedance are calculated using the minimum operation of maximum, that is, system, DFIG and FIDG equivalent impedances are using minimum
Value is that rated capacity calculates.
In formula, ZABFor the impedance of circuit AB；Z'DFIGFor DFIG impedance perunit values, size is：Z'DFIG=ZDFIG(Us/
E'DFIG)2；E'DFIGBy DFIG output calculations；Z'DFIG//Z'FIDGFor DG parallel impedances, computational methods are similar when multiple DG are accessed；
Z'FIDGFor FIDG impedance perunit values, Z'FIDG=(Is/IFIDG), I during line to line faultFIDGIt is calculated by FIDG rated capacities, three-phase is short
I during roadFIDGFor current transformer current threshold.
Step S3, protection act module sends trip signal, driving is jumped according to the result of decision to corresponding breaker
Lock acts.
The present invention has the beneficial effect that：
The protection system and method has considered the fault transient characteristic of full inverse type DG and half inverse type DG, is formed
Unified adaptive direction current protection criterion, it is adaptable from DG patterns affects；In different running method and failure
Under type, by measurement electric current and voltage according to different criterions in line computation setting valve, reliability is higher；Adaptive electric current in limited time
Fast tripping protection can be acted correctly, sensitivity is higher when reply Voltage Drop and low voltage crossing.
Consider the fault transient characteristic of half inverse type DG and full inverse type DG in detail in failure equivalence, can accurately reflect
Distribution network failure situation.Asynchronous machine can be equivalent to for the full inverse type DG with low voltage ride-through capability, ignores high frequency transient
Methods described herein still can be used after component and carry out equivalence.In addition, adaptive direction overcurrent protection scheme is online according to measured value
DG short circuit current flows are reduced rapidly caused relay fail situation after calculating can also avoid low voltage crossing.
It will be understood by those skilled in the art that realizing all or part of flow of above-described embodiment method, meter can be passed through
Calculation machine program instructs relevant hardware to complete, and the program can be stored in computer readable storage medium.Wherein, institute
Computer readable storage medium is stated as disk, CD, read-only memory or random access memory etc..
The foregoing is only a preferred embodiment of the present invention, but protection scope of the present invention be not limited thereto,
Any one skilled in the art in the technical scope disclosed by the present invention, the change or replacement that can be readily occurred in,
It should be covered by the protection scope of the present invention.
Claims (8)
1. a kind of current protection method of power distribution network containing DG, which is characterized in that comprise the following steps：
Step S1, the power distribution network supplemental characteristic of fault information acquisition module acquisition secondary protector installation place, and be uploaded to certainly
Adapt to overcurrent protection module；
Step S2, the supplemental characteristic that adaptive Current Protection module uploads fault information acquisition module is handled, according to pre-
If operating criterion identifies fault message and obtains corresponding decision as a result, and the result of decision is sent to protection act module；
Step S3, protection act module sends trip signal, driving tripping is dynamic according to the result of decision to corresponding breaker
Make；
The operating criterion is adaptive direction current protection criterion under different faults type, including：
The operating criterion of I section of self-adaptive current, two-phase under the operating criterion of I section of self-adaptive current, three-phase shortcircuit under line to line fault
The operating criterion of II section of self-adaptive current under the operating criterion and three-phase shortcircuit of lower II section of the self-adaptive current of short circuit.
2. the current protection method of power distribution network containing DG according to claim 1, which is characterized in that the power distribution network supplemental characteristic
Including：
Protect installation place fault current Imf, I section of action current I of self-adaptive currentZDZ,I, protect back side equivalence potentialThe protection back of the body
Side equivalent impedance Ze, line impedance ZL, peak response angleProtect installation place positive sequence false voltage steady-state componentIt protects
Protect the positive sequence fault current steady-state component that installation place is free of DG mutation currents
Protect installation place measurement voltageProtect installation place false voltage Sudden Changing RateProtect the mutation of installation place fault current
Amount
II section of action current I of self-adaptive currentZDZ,Ⅱ, this line impedance ZsL, subordinate line impedance ZnL, I section of protection model of subordinate's circuit
Enclose βnL, braning factor Kb。
3. the current protection method of power distribution network containing DG according to claim 1, which is characterized in that the adaptive direction electric current
Protection criteria is obtained by following steps：
The fault transient characteristic and failure equivalence method of sub-step S21, analysis different type DG, computing system short circuit current flow institute
Containing component, the relation between three phase components of short circuit current flow is obtained；
Sub-step S22, according to failure boundary condition, obtain system failure steady-state component, the measurement voltage of join protection installation place
And measurement electric current, calculate threshold voltages and the equivalent impedances such as protection back side；
Adaptive direction current protection criterion under sub-step S23, construction different faults type.
4. the current protection method of power distribution network containing DG according to claim 1, which is characterized in that
The adaptive direction current protection criterion has fault type judgment mechanism in itself, as long as meeting criterion, you can clearly
Fault type.
5. the current protection method of power distribution network containing DG according to claim 1, which is characterized in that the step S2 is further wrapped
It includes：
If gathered data continuously meets the operating criterion of I section of self-adaptive current, corresponding decision is obtained as a result, and by the result of decision
Protection act module is sent to, the result of decision is I sections of actions of protection；
If gathered data continuously meets the operating criterion of II section of self-adaptive current, corresponding decision is obtained as a result, simultaneously after the Δ t that is delayed
The result of decision is sent to protection act module, the result of decision is II section of action of protection.
6. a kind of current protection system of power distribution network containing DG, the system comprises fault information acquisition module, adaptive Current Protections
Module and protection act module, for any one of perform claim requirement 1-5 the method, wherein,
The fault information acquisition module is used to gather the power distribution network supplemental characteristic of secondary protector installation place, and is uploaded to certainly
Adapt to overcurrent protection module；
The adaptive Current Protection module is used for the power distribution network supplemental characteristic that handling failure information acquisition module uploads, according to pre-
If operating criterion identifies fault message and obtains corresponding decision as a result, the result of decision is sent to protection act module；
The protection act module is used to, according to the result of decision, instruct to breaker sending action, indicates circuit breaker trip
Or it is failure to actuate；
The deliberate action criterion is adaptive direction current protection criterion under different faults type, including：
The operating criterion of I section of self-adaptive current, two-phase under the operating criterion of I section of self-adaptive current, three-phase shortcircuit under line to line fault
The operating criterion of II section of self-adaptive current under the operating criterion and three-phase shortcircuit of lower II section of the self-adaptive current of short circuit.
7. the current protection system of power distribution network containing DG according to claim 6, which is characterized in that the adaptive direction electric current
Protection criteria has fault type judgment mechanism in itself, as long as meeting one of criterion, you can clear failure type, corresponding protection are
It is actionable.
8. the current protection system of power distribution network containing DG according to claim 6, which is characterized in that the adaptive direction electric current
Protection criteria is obtained especially by following steps：
The fault transient characteristic and failure equivalence method of analysis different type DG, component contained by computing system short circuit current flow, and
Disclose the relation between three phase components of short circuit current flow；
According to failure boundary condition, system failure steady-state component is obtained, measurement voltage and measurement electricity in conjunction with protection installation place
Stream calculates threshold voltages and the equivalent impedances such as protection back side；
Construct adaptive direction current protection criterion under different faults type.
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| CN106340863B (en) * | 2016-11-14 | 2018-05-08 | 国网天津市电力公司 | A kind of guard method of adaptive transient current quick-break |
| CN109193584B (en) * | 2016-11-14 | 2019-11-05 | 国网江苏省电力公司常州供电公司 | A kind of current protection method of the power distribution network containing distributed photovoltaic power |
| CN109428315B (en) * | 2017-08-23 | 2020-07-07 | 天津市中力神盾电子科技有限公司 | Self-adaptive protection method, device and system |
| CN112444667B (en) * | 2019-09-02 | 2024-02-13 | 南京理工大学 | Boundary protection method for direct-current power distribution network |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1939999A2 (en) * | 2006-12-28 | 2008-07-02 | General Electric Company | Circuit protection system |
| CN101562333A (en) * | 2009-05-27 | 2009-10-21 | 天津大学 | Fast current protection method for distribution network containing distributed power |
| CN101562332A (en) * | 2009-05-27 | 2009-10-21 | 天津大学 | Self-adaptive current fast tripping protection method for distribution network comprising inverse distributed power |
| CN103872665A (en) * | 2014-03-26 | 2014-06-18 | 国家电网公司 | Power distribution network integrated protection method suitable for access of distributed power supplies |
| CN104882864A (en) * | 2015-04-30 | 2015-09-02 | 国家电网公司 | Re-setting method and system for current protection containing photovoltaic power distribution network |
-
2016
- 2016-07-26 CN CN201610597547.3A patent/CN106058830B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1939999A2 (en) * | 2006-12-28 | 2008-07-02 | General Electric Company | Circuit protection system |
| CN101562333A (en) * | 2009-05-27 | 2009-10-21 | 天津大学 | Fast current protection method for distribution network containing distributed power |
| CN101562332A (en) * | 2009-05-27 | 2009-10-21 | 天津大学 | Self-adaptive current fast tripping protection method for distribution network comprising inverse distributed power |
| CN103872665A (en) * | 2014-03-26 | 2014-06-18 | 国家电网公司 | Power distribution network integrated protection method suitable for access of distributed power supplies |
| CN104882864A (en) * | 2015-04-30 | 2015-09-02 | 国家电网公司 | Re-setting method and system for current protection containing photovoltaic power distribution network |
Non-Patent Citations (2)
| Title |
|---|
| 含逆变型分布式电源的配电网自适应正序电流速断保护;陈晓龙等;《电力系统自动化》;20150510;第39卷(第9期);第107-112页 * |
| 含逆变型分布式电源配电网自适应电流速断保护;孙景钌等;《电力系统自动化》;20090725;第33卷(第14期);第71-76页 * |
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