CN105914776A - Quick intelligent anti-island system and quick intelligent anti-island method with power grid fault self-recovering capability - Google Patents
Quick intelligent anti-island system and quick intelligent anti-island method with power grid fault self-recovering capability Download PDFInfo
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- CN105914776A CN105914776A CN201610226827.3A CN201610226827A CN105914776A CN 105914776 A CN105914776 A CN 105914776A CN 201610226827 A CN201610226827 A CN 201610226827A CN 105914776 A CN105914776 A CN 105914776A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/40—Synchronising a generator for connection to a network or to another generator
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
Abstract
The invention provides a quick intelligent anti-island system and a quick intelligent anti-island method with power grid fault self-recovering capability. The method comprises the steps of a first step, establishing the main circuit of a distributed power generating grid-connected system; a second step, injecting phase angle fluctuation in the control circuit of the grid-connected system by an active phase deviation module; and a third step, based on the voltage signal of a common connecting point in the grid-connected system and a power grid frequency signal which is obtained by a phase-locked loop, realizing island detection and power grid fault self-recovering, wherein the common connecting point is the accessing position of a grid-connected filter and a local load into the power grid. The quick intelligent anti-island system and the quick intelligent anti-island method can quickly detect the island, and adding of additional hardware such as sensor is not required in the distributed power generating grid-connected system in which the phase-locked ring is used for realizing power grid synchronization. On the extreme condition that the system local load is a parallel RLC load which matches the power of the distributed power generating system, operation state of the island can be quickly and accurately detected. Furthermore no detection blind area exists and system operation efficiency can be effectively improved.
Description
Technical field
The present invention relates to the anti-islanding protection field of distributed power generation grid-connected system, in particular it relates to one has electrical network
The quick, intelligent anti-islanding system and method for fault self-recovery ability.
Background technology
Along with fossil energy is the most exhausted, the new forms of energy such as solar energy, wind energy, fuel cell have obtained extensive exploitation and use.
These Distributed-generation equipment access electrical network by power inverter, carry electric energy to electrical network.Grid-connected for distributed power generation
, there is this potential safety hazard of island effect in system.Island effect refers to, in distributed power generation grid-connected system, when main electricity
Net because of maintenance or the reason such as break down cut-off after, generating equipment continues to power to the load, and forms the phenomenon of power supply isolated island.
Island effect as can not be timely detected out, then can occur following danger:
(1) owing to network system being equiped with auto recloser, if electricity generation system does not possess anti-islanding ability,
Very possible there is TRT and the nonsynchronous situation of electrical network when system reclosing, and may produce the biggest impact electricity
Stream, damages circuit-breaker and TRT, even causes electrical network again to trip；
(2) due under island state, system departs from operation of power networks, voltage and frequency situation out of control easily occurs.As
Really TRT does not possess voltage, frequency regulation capability, does not the most possess anti-islanding ability and cuts out island state in time, then has
Bigger voltage, frequency fluctuation may be produced, damage electrical network and electrical equipment；
(3) when electrical network occurs ground connection or phase fault tripping operation, island effect can hinder the removing of fault, and
The automatic or manual recovery of electrical network can be disturbed；
(4) during electrical network tripping operation maintenance, the circuit that island effect can make with main electrical network disconnects is the most charged, can be to maintenance people
The safety of member produces and threatens.Therefore, when distributed power generation grid-connected system is in island operation state, orphan is detected in time
Island state to take anti-islanding protection action be necessary.
The method of isolated island detection can be divided into passive detection and active detecting.Passive detection method based on to voltage magnitude, phase place,
The monitoring that frequency and harmonic components etc. are abnormal, such method is simple, it is easy to accomplish, but there is bigger check frequency；Main
Dynamic detection method by applying specific skew or disturbance to electrical network, and then judges according to the reaction of electrical network, such side
Method can effectively reduce isolated island check frequency, but method is more complicated, generally to apply skew or disturbance to electrical network, therefore can be right
Power grid quality produces harmful effect.Because check frequency can directly influence the reliability of anti-islanding protection, so using main
Dynamic detection method also reduces the feasible program that the impact on power grid quality is isolated island detection.
It addition, power system possesses certain self-healing ability, such as automatic reclosing after transient fault occurs in electrical network, can be passed through
Restore electricity Deng equipment.But existing anti-island method does not the most possess self-healing ability, the most lonely at distributed power generation grid-connected system
After the action of island, need can again access electrical network after artificial judgment operates.Which not only adds distributed power generation also
The maintenance workload of net system, and reduce operational efficiency and the economic benefit of electricity generation system.Visible have electric network fault
The intelligent anti-island method engineering practicability of self-healing ability is higher, more can adapt with intelligent grid and energy the Internet.
Summary of the invention
For defect of the prior art, it is an object of the invention to provide and a kind of there is the quick of electric network fault self-healing ability
Intelligence anti-islanding system and method.
The quick, intelligent anti-islanding system with electric network fault self-healing ability provided according to the present invention, it is characterised in that bag
Include: Grid-connected Distributed Generation Power System main circuit, Active phase skew (APD) disturbance module and anti-islanding Intelligent Measurement
Module；
Described Grid-connected Distributed Generation Power System main circuit includes: distributed power source, power inverter, grid-connected wave filter, basis
Ground load and electrical network；One end of described distributed power source is connected with one end of grid-connected wave filter by power inverter, institute
The other end stating grid-connected wave filter is connected with electrical network through the first chopper, and local load is connected with electrical network through the second chopper；
The position that the most grid-connected wave filter and local load access electrical network is referred to as points of common connection (PCC)；
Described Active phase skew disturbance module, acts in the control circuit of Grid-connected Distributed Generation Power System, coordinates anti-lonely
Island Intelligent Measurement module realizes actively isolated island detection；Control circuit uses phaselocked loop to realize distributed power source grid-connected current and electricity
The real-time synchronization of net voltage, the input quantity of phaselocked loop be through Clarke conversion with the main electricity of described Grid-connected Distributed Generation Power System
The voltage of points of common connection in road, output be locking electric network voltage phase angle and for described anti-islanding Intelligent Measurement
The mains frequency signal of module；Described Active phase skew disturbance module adds to the electric network voltage phase angle of phase lock loop locks
Appropriate phase angle shift, and the synchronized link in cutting-in control circuit；
Described anti-islanding Intelligent Measurement module, for points of common connection in described Grid-connected Distributed Generation Power System main circuit
The mains frequency signal that voltage signal and phaselocked loop obtain is for according to realizing isolated island detection and electric network fault spontaneous recovery.
Described distributed power source includes: in photovoltaic battery array, fuel cell, accumulator, wind-powered electricity generation, diesel-driven generator
Any one；And the type matching of described power inverter and distributed power source, wherein, DC source correspondence inverter,
Alternating current power supply correspondence commutation inversion code converter；
Described grid-connected wave filter includes: any one in L-type wave filter, LC mode filter or LCL type wave filter；
Described local load includes: the three-phase symmetrical passive load of random capacity and connected mode.
Described Active phase skew disturbance module injects phase angle shift directly to grid voltage phase-angle, wherein, and phase angle shift
Size must according to the switching frequency of control circuit and and the requirement of network electric energy quality adjust；Phase angle shift is the least, grid-connected electricity
Energy quality is the highest, but the speed of isolated island detection is the slowest.
Described anti-islanding Intelligent Measurement module includes: isolated island detection module and electric network fault spontaneous recovery module,
Described isolated island detection module, is used for detecting whether Grid-connected Distributed Generation Power System is in island operation state, when phase-locked
The mains frequency signal that ring obtains is at time t0Beyond electrical network allowed band (under IEEE 1547 standard it is the most persistently
49.3Hz～50.5Hz) time, i.e. judge that Grid-connected Distributed Generation Power System is in island operation state, starts anti-islanding protection；
Otherwise start electric network fault spontaneous recovery module；
Described electric network fault spontaneous recovery module, is used for detecting Grid-connected Distributed Generation Power System the need of releasing anti-islanding protection shape
State, when Grid-connected Distributed Generation Power System is in anti-islanding protection state, and at points of common connection, voltage magnitude absolute value is higher than
Threshold voltage UthAccumulated time reach time t1Time, i.e. judge that electric network fault eliminates, release anti-islanding protection, extensive
Generate electricity by way of merging two or more grid systems again；Otherwise close electric network fault spontaneous recovery module.
The quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention, comprises the steps:
Step 1: build the main circuit of distributed power generation grid-connected system；
Step 2: injected phase angle disturbance to control circuit by Active phase skew disturbance module；
Step 3: the electrical network obtained by the voltage signal of points of common connection in power grid system in a distributed manner and phaselocked loop
Frequency signal is foundation, it is achieved isolated island detection and electric network fault spontaneous recovery, and described points of common connection refers to grid-connected wave filter and basis
Ground load accesses the position of electrical network.
The Grid-connected Distributed Generation Power System main circuit built in step 1 includes: distributed power source, power inverter, grid-connected
Wave filter, local load and electrical network；One end of described distributed power source is by power inverter and the one of grid-connected wave filter
End is connected, and the other end of described grid-connected wave filter is connected with electrical network through the first chopper, local load through the second chopper and
Electrical network is connected；The position that the most grid-connected wave filter and local load access electrical network is referred to as points of common connection.
Described distributed power source includes: in photovoltaic battery array, fuel cell, accumulator, wind-powered electricity generation, diesel-driven generator
Any one；And the type matching of described power inverter and distributed power source, wherein, DC source correspondence inverter,
Alternating current power supply correspondence rectification-inverse type changer；
Described grid-connected wave filter includes: any one in L-type wave filter, LC mode filter or LCL type wave filter；
Described local load includes: the three-phase symmetrical passive load of random capacity and connected mode.
Described step 2 includes: add appropriate phase angle shift to the electric network voltage phase angle of phase lock loop locks, and for also
Synchronized link in net control circuit, wherein, the size of phase angle shift must according to the switching frequency of control circuit and also
The requirement of network electric energy quality is adjusted；Phase angle shift is the least, and network electric energy quality is the highest, but the speed of isolated island detection is more
Slowly.
Described step 3 includes:
Step 3.1: gather the voltage signal of points of common connection in the grid-connected main circuit of distributed power source, and obtained electricity by phaselocked loop
Net frequency signal；
Step 3.2: isolated island detecting step, the mains frequency signal i.e. obtained when phaselocked loop is at time t0The most persistently beyond electrical network
During allowed band (being 49.3Hz～50.5Hz under IEEE 1547 standard), i.e. decision-making system is in island operation state,
Start anti-islanding protection；Otherwise perform step 3.3；
Step 3.3: judge whether Grid-connected Distributed Generation Power System meets and be in anti-islanding protection state, and at points of common connection
Voltage magnitude absolute value is higher than threshold voltage UthAccumulated time reach time t1, when meeting, it is determined that electric network fault is
Eliminate, release anti-islanding protection, recover to generate electricity by way of merging two or more grid systems；If being unsatisfactory for, then terminating, preparing to detect next time.
Compared with prior art, the present invention has a following beneficial effect:
1, the quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention can quickly detect
Go out isolated island, to the distributed power generation grid-connected system using phaselocked loop to realize synchronized, it is not necessary to add any extra biography
The hardware such as sensor；Wherein, anti-islanding Intelligent Measurement algorithm the most easily realizes, because mains frequency can be directly by phase-locked
Ring obtains.
2, the quick, intelligent anti-islanding system with electric network fault self-healing ability provided according to the present invention, local in system
Load is for, under the extreme case of the RLC in parallel load matched with distributed generation system power, remaining to rapidly and accurately
Detect island operation state, there is not check frequency.
3, the quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention can be protected at isolated island
Detect after protecting action that state that electric network fault eliminates recovery system generate electricity by way of merging two or more grid systems rapidly and accurately, occur instantaneous at electrical network
Under the similar situations such as fault success automatic reclosing, the maintenance workload of distributed power generation grid-connected system can be greatly reduced,
It is effectively improved running efficiency of system.
Accompanying drawing explanation
By the detailed description non-limiting example made with reference to the following drawings of reading, the further feature of the present invention,
Purpose and advantage will become more apparent upon:
Fig. 1 is the main circuit structure schematic diagram of distributed power generation grid-connected system；
Fig. 2 is the flowchart of anti-islanding Intelligent Measurement algorithm；
Fig. 3 be Active phase skew (APD) disturbance module realize block diagram；
Fig. 4 is the grid-connected current oscillogram after Active phase skew disturbance module injects disturbance；
Fig. 5 is the result figure of MATLAB environment Imitating electric network fault inspection anti-islanding Intelligent Measurement algorithm validity.
In figure:
1-distributed power source；
2-power inverter；
The grid-connected wave filter of 3-；
4-the first chopper；
5-points of common connection (PCC)；
6-this locality loads；
7-the second chopper；
8-electrical network；
9-mains voltage signal；
10-Clarke converts；
11-phaselocked loop；
12-phase angle shift；
13-adder；
Synchronized link in 14-cutting-in control circuit.
Detailed description of the invention
Below in conjunction with specific embodiment, the present invention is described in detail.Following example will assist in those skilled in the art
Member is further appreciated by the present invention, but limits the present invention the most in any form.It should be pointed out that, the common skill to this area
For art personnel, without departing from the inventive concept of the premise, it is also possible to make some changes and improvements.These broadly fall into
Protection scope of the present invention.
The present invention proposes a kind of quick, intelligent anti-island method with electric network fault self-healing ability, at the disturbance base injected
On the premise of this does not affects power grid quality, the island operation state of distributed power generation grid-connected system can be detected rapidly and accurately,
And after electric network fault is removed, have and automatically access the self-healing ability that electrical network continues to generate electricity by way of merging two or more grid systems.Not only solve tradition anti-
Isolated island method is difficult to take into account detection reliability and the problem of power grid quality, and effectively reduces non-self-cure type anti-island method
The maintenance workload brought, improves operational efficiency and the economic benefit of electricity generation system.
Distributed power source is included according to the quick, intelligent anti-island method with electric network fault self-healing ability that the present invention provides
Grid-connected system main circuit, Active phase skew (APD) disturbance method for implanting and anti-islanding Intelligent Measurement algorithm.
Wherein, Grid-connected Distributed Generation Power System main circuit includes distributed power source, power inverter, grid-connected wave filter, basis
Ground load and electrical network.Distributed power source can be the DC sources such as photovoltaic battery array, fuel cell, accumulator, it is possible to
To be the alternating current power supply such as wind-powered electricity generation, diesel-driven generator；Power inverter must match with power supply type, and DC source correspondence is inverse
Become device, alternating current power supply correspondence rectification-inverse type changer；Grid-connected wave filter can use L-type, LC type or LCL type
Wave filter；Local load can be the three-phase symmetrical passive load of random capacity and connected mode.Distributed power source and power
Changer is connected, and wherein, DC source uses two-wire connected mode, and alternating current power supply uses three-wire connection mode；Grid-connected filter
Ripple device one end is connected with power inverter, and the other end is connected with electrical network through chopper；Local load is through another chopper and electricity
Net is connected.The position that grid-connected wave filter and local load access electrical network is referred to as points of common connection (PCC), and grid-connected voltage exists
This point sampling.
Active phase skew disturbance method for implanting is in distributed power generation cutting-in control circuit, to the electrical network of phase lock loop locks
Voltage phase angle adds appropriate phase angle shift, obtains keeping Tong Bu as grid-connected current in control circuit with line voltage
Reference signal.It is characterized in that, inject phase angle shift directly to grid voltage phase-angle, be different from existing must employing the most frequently
The injection mode of rate skew (AFD) method, has an advantage in that method is simpler, and being also easier to adjust out meets the requirements
Side-play amount.Wherein, the size of phase angle shift amount must be according to the switching frequency of control circuit and and the requirement of network electric energy quality
Adjust；Phase angle shift amount is the least, and network electric energy quality is the highest, but the speed of isolated island detection is the slowest, so should select
Take suitable side-play amount, both met the requirement of isolated island detection time, and had substantially no effect on again power grid quality；Carry with switching frequency
Height should suitably reduce phase angle shift amount.
Anti-islanding Intelligent Measurement algorithm mainly comprises isolated island detection and electric network fault spontaneous recovery two parts.Isolated island detection criteria is:
Whether the mains frequency signal obtained by phaselocked loop is at time t0The most persistently (mark at IEEE 1547 beyond electrical network allowed band
Accurate lower for 49.3Hz～50.5Hz).If criterion meets, then it is judged to island operation state, starts anti-islanding protection, otherwise
Enter electric network fault spontaneous recovery to judge.Electric network fault spontaneous recovery criterion is: system has been in anti-islanding protection state and public the most
At junction point, voltage magnitude absolute value is higher than threshold voltage UthAccumulated time reach time t1.If criterion meets, then sentence
Determine electric network fault to eliminate, release anti-islanding protection, recover to generate electricity by way of merging two or more grid systems, otherwise enter next round detection.Time t0Preferably
Adjust at Microsecond grade, the requirement of isolated island detection speed can be met, anti-islanding protection can be prevented again because of sampling singular value, be
The system reason misoperation such as interference, the concrete time can detect the requirement of speed according to loadtype and isolated island and suitably adjust；Time
t1Must be with threshold voltage UthMatch, when judging with phase voltage, UthIn the range of being preferably chosen at 300～310, this
Time by time t1Adjust at Microsecond grade, and suitably increase U with the reduction of load capacitythValue, suitably reduces the time simultaneously
t1Setting valve, so can accurately detect in 0.1s that state that electric network fault eliminates recovery are generated electricity by way of merging two or more grid systems, with line
When voltage judges similar.
The present invention comprises the steps:
Step S1: build the main circuit of distributed power generation grid-connected system；
Specifically, as it is shown in figure 1, be the main circuit structure of distributed power generation grid-connected system, including distributed power source 1,
Power inverter 2, grid-connected wave filter 3, local load 6 and electrical network 8.Described distributed power source 1 connects merit by electric wire
Rate changer 2；Described grid-connected wave filter 3 one end connects power inverter 2 by electric wire, and the other end is by electric wire and the
The points of common connection 5 with electrical network 8 direct connection is accessed after one chopper 4 series connection；Described local load 6 is by electric wire and second
The points of common connection 5 with electrical network 8 direct connection is accessed after chopper 7 series connection.
Step S2: use anti-islanding Intelligent Measurement algorithm to realize isolated island detection and electric network fault spontaneous recovery；
Specifically, as in figure 2 it is shown, include:
Step S2.1: use Active phase offset method to inject anti-islanding disturbance；Gather in the grid-connected main circuit of distributed power source
The voltage signal of points of common connection 5, and obtained mains frequency signal by phaselocked loop；
Step S2.2: whether be in island operation state according to the mains frequency signal determining system that phaselocked loop obtains.When being
When system is without departing from electrical network, owing to TRT capacity is much smaller compared with net capacity, the phase angle disturbance of injection can't be to electricity
Net phase place produce significantly affect, next phase-locked time remain to be synchronized to grid phase；Once system departs from electrical network with island state
Run, be then the unique power supply of system due to distributed power source, the phase angle disturbance of injection can substantially reflection phase-locked to next time
On phase angle, and then form positive feedback so that the skew of phase angle is increasing, so that system frequency deviation electrical network power frequency,
When frequency departure i.e. triggers anti-islanding protection beyond electrical network allowed band.Arranging isolated island detection criteria is: obtained by phaselocked loop
Mains frequency signal whether at time t0Beyond electrical network allowed band (under IEEE 1547 standard it is the most persistently
49.3Hz～50.5Hz).If criterion is set up, then it is judged to island operation state, performs step S2.3, otherwise perform step
S2.4；
Step S2.3: perform anti-islanding protection action, performs step S2.6；
Step S2.4: electric network fault spontaneous recovery judge, after electric network fault is removed and is restored electricity, at PCC voltage magnitude and
Frequency will recover rapidly normal.Arranging electric network fault spontaneous recovery criterion is: system has been in anti-islanding protection state and public affairs the most
At junction point, voltage magnitude absolute value is higher than threshold voltage U altogetherthAccumulated time reach time t1If criterion is set up, then
Judge that electric network fault eliminates, perform step S2.5；Otherwise perform step S2.6；
Step S2.5: release anti-islanding protection, recover to generate electricity by way of merging two or more grid systems, performs step S2.6；
Step S2.6: epicycle anti-islanding detection terminates, enters next round detection.
In described step S2.1, the feature of Active phase skew disturbance method for implanting is: as it is shown on figure 3, commonly connected
Gathering mains voltage signal 9 at point 5, the voltage signal obtained converts 10 from three-phase by Clarke after Filtering Processing
Rest frame is converted into biphase rest frame, by the two-way voltage signal under the biphase rest frame obtained through lock
Phase ring 11 can obtain grid voltage phase-angle θ ' and the mains frequency f for anti-islanding detection algorithm；To line voltage phase
Angle θ ' injects suitable phase angle shift 12 by adder 13 and keeps Tong Bu benchmark phase angle to believe as grid-connected system with electrical network
Number θ.Wherein, the size of phase angle shift 12 must according to the switching frequency of control circuit and and network electric energy quality requirement come whole
Fixed；Phase angle shift 12 is the least, and network electric energy quality is the highest, but the speed of isolated island detection is the slowest, so should choose
Suitably phase angle shift 12, can meet the requirement of isolated island detection time, have substantially no effect on again power grid quality；With switch lock
Rate improves can suitably reduce phase angle shift 12.
Closer, when the RLC in parallel load that system access matches with distributed generation system power, switching frequency
For 10kHz, phase angle shift 12 is taken as-0.1rad, and grid-connected current waveform is as shown in Figure 4；Grid-connected current can be with as seen from the figure
Voltage keeps homophase and substantially in good sinusoidal wave form, does the note of phase angle shift knowable to harmonic wave and Power Factor Analysis further
Enter not increase the harmonic wave of system power, power factor simply can be made to be declined slightly, but still more than 99%.
The setting method relating to parameter in described step S2 is: time t0Preferably adjust at Microsecond grade, isolated island inspection can be met
The requirement of degree of testing the speed, can prevent again anti-islanding protection because of the sampling reason misoperation such as singular value, system interference, concrete time
Suitably can adjust according to the requirement of loadtype and isolated island detection speed；Time t1Must be with threshold voltage UthMatch, when
Carry out judging with phase voltage and electrical network specified phase voltage virtual value as 220V time, UthIn the range of being preferably chosen at 300～310,
Now by time t1Adjust at Microsecond grade, and suitably increase U with the reduction of load capacitythValue, when suitably reducing simultaneously
Between t1Setting valve, so can accurately detect in 0.1s that state that electric network fault eliminates recovery are generated electricity by way of merging two or more grid systems.
Further, when distributed power generation grid-connected system accesses the RLC in parallel load matched with this system power, negative
When load resonant frequency is power frequency 50Hz；Parameter tuning is t0=1ms, t1=1ms, Uth=310V；The instantaneous event of simulating grid
Barrier automatic reclosing, when system start-up 0.1s, electrical network is because of fault power-off, and automatic reclosing success when 0.25s,
Power system restoration is powered.Result is as it is shown in figure 5, during 0～0.1s, electrical network and distributed power generation grid-connected system are all normal, to the greatest extent
Pipe uses Active phase offset method to be filled with anti-islanding disturbance, but the mains frequency that phaselocked loop records is always stable in power frequency
50Hz；In 0.1s moment grid collapses power-off, distributed generation system enters island operation state, due to distribution
Formula power supply becomes the unique power supply of system, and the anti-islanding disturbance using Active phase offset method to inject makes system frequency fast
Speed deviation electrical network power frequency, triggers anti-islanding protection action, isolated island detection time when frequency departure meets isolated island detection criteria
Then only need to be less than 55ms, much smaller than the time of ieee standard 1547 regulation；After anti-islanding protection action, electricity at PCC
Pressure reduces to rapidly zero, but due to the resonance loaded and the shadow of phaselocked loop feedforward compensation (in order to accelerate phase-locked speed)
Ringing, phase-lock-ring output frequency can be restrained to power frequency after vibration in short-term, and it is 0.15s that this example takes the automatic reclosing response time,
I.e. the short reaction time of electrical network regulation, can preferably investigate the self-healing ability of anti-islanding Intelligent Measurement algorithm；At 0.25s
Moment power system restoration is powered, and at PCC, voltage gradually recovers normal, sentences when voltage magnitude and frequency meet electric network fault spontaneous recovery
According to time, distributed generation system release anti-islanding protection, recover to generate electricity by way of merging two or more grid systems, the response time only need to be less than 0.04s.
The result of embodiment demonstrates quick, intelligent anti-island method proposed by the invention, it is possible at the disturbance base injected
On the premise of this does not affect the electrical network quality of power supply, detect the islet operation shape of distributed power generation grid-connected system rapidly and accurately
State, and after electric network fault eliminates, have and automatically access the self-healing ability that electrical network continues to generate electricity by way of merging two or more grid systems.
Above the specific embodiment of the present invention is described.It is to be appreciated that the invention is not limited in
Stating particular implementation, those skilled in the art can make a variety of changes within the scope of the claims or revise,
This has no effect on the flesh and blood of the present invention.In the case of not conflicting, in embodiments herein and embodiment
Feature can arbitrarily be mutually combined.
Claims (9)
1. a quick, intelligent anti-islanding system with electric network fault self-healing ability, it is characterised in that including: distributed
Power grid system main circuit, Active phase skew disturbance module and anti-islanding Intelligent Measurement module；
Described Grid-connected Distributed Generation Power System main circuit includes: distributed power source (1), power inverter (2), grid-connected filter
Ripple device (3), local load (6) and electrical network (8)；Power inverter is passed through in one end of described distributed power source (1)
(2) one end with grid-connected wave filter (3) is connected, and the other end of described grid-connected wave filter (3) is through the first chopper (4)
Being connected with electrical network (8), local load is connected with electrical network (8) through the second chopper (7)；The most grid-connected wave filter (3)
The position accessing electrical network (8) with this locality load (6) is referred to as points of common connection (5)；
Described Active phase skew disturbance module, acts in the control circuit of Grid-connected Distributed Generation Power System, coordinates anti-lonely
Island Intelligent Measurement module realizes actively isolated island detection；
Described anti-islanding Intelligent Measurement module, for points of common connection (5) in described Grid-connected Distributed Generation Power System main circuit
Voltage signal and the mains frequency signal that obtains of phaselocked loop (11) for according to realizing isolated island detection and electric network fault spontaneous recovery.
The quick, intelligent anti-islanding system with electric network fault self-healing ability the most according to claim 1, its feature exists
In,
Described distributed power source (1) including: photovoltaic battery array, fuel cell, accumulator, wind-powered electricity generation, diesel-driven generator
In any one；And the type matching of described power inverter (2) and distributed power source (1), wherein, unidirectional current
Source correspondence inverter, alternating current power supply correspondence commutation inversion code converter；
Described grid-connected wave filter (3) including: any one in L-type wave filter, LC mode filter or LCL type wave filter；
Described local load (6) including: the three-phase symmetrical passive load of random capacity and connected mode.
The quick, intelligent anti-islanding system with electric network fault self-healing ability the most according to claim 1, its feature exists
In, described Active phase skew disturbance module injects phase angle shift (12), wherein, phase angle directly to grid voltage phase-angle
The size of skew (12) must according to the switching frequency of control circuit and and the requirement of network electric energy quality adjust；Phase angle shift
(12) the least, and network electric energy quality is the highest, but the speed of isolated island detection is the slowest.
The quick, intelligent anti-islanding system with electric network fault self-healing ability the most according to claim 1, its feature exists
In, described anti-islanding Intelligent Measurement module includes: isolated island detection module and electric network fault spontaneous recovery module；
Described isolated island detection module, is used for detecting whether Grid-connected Distributed Generation Power System is in island operation state, when phase-locked
The mains frequency signal that ring (11) obtains is at time t0Time the most persistently beyond electrical network allowed band, i.e. judge distributed power source
Grid-connected system is in island operation state, starts anti-islanding protection；Otherwise start electric network fault spontaneous recovery module；
Described electric network fault spontaneous recovery module, is used for detecting Grid-connected Distributed Generation Power System the need of releasing anti-islanding protection shape
State, when Grid-connected Distributed Generation Power System is in anti-islanding protection state, and points of common connection (5) place voltage magnitude is absolute
Value is higher than threshold voltage UthAccumulated time reach time t1Time, i.e. judge that electric network fault eliminates, release anti-islanding and protect
Protect, recover to generate electricity by way of merging two or more grid systems；Otherwise close electric network fault spontaneous recovery module.
5. a quick, intelligent anti-island method with electric network fault self-healing ability, it is characterised in that comprise the steps:
Step 1: build the main circuit of distributed power generation grid-connected system；
Step 2: injected phase angle disturbance to control circuit by Active phase skew disturbance module；
Step 3: by the voltage signal of points of common connection (5) in power grid system in a distributed manner and phaselocked loop (11)
The mains frequency signal obtained is foundation, it is achieved isolated island detection and electric network fault spontaneous recovery, described points of common connection (5) is
Refer to that grid-connected wave filter (3) and local load (6) access the position of electrical network (8).
The quick, intelligent anti-island method with electric network fault self-healing ability the most according to claim 5, its feature exists
In, the Grid-connected Distributed Generation Power System main circuit built in step 1 includes: distributed power source (1), power inverter (2),
Grid-connected wave filter (3), local load (6) and electrical network (8)；Power is passed through in one end of described distributed power source (1)
Changer (2) is connected with one end of grid-connected wave filter (3), and the other end of described grid-connected wave filter (3) breaks through first
Road device (4) is connected with electrical network (8), and local load is connected with electrical network (8) through the second chopper (7)；The most grid-connected
The position that wave filter (3) and local load (6) access electrical network (8) is referred to as points of common connection (5).
The quick, intelligent anti-island method with electric network fault self-healing ability the most according to claim 6, its feature exists
In,
Described distributed power source (1) including: photovoltaic battery array, fuel cell, accumulator, wind-powered electricity generation, diesel-driven generator
In any one；And the type matching of described power inverter (2) and distributed power source (1), wherein, unidirectional current
Source correspondence inverter, alternating current power supply correspondence commutation inversion code converter；
Described grid-connected wave filter (3) including: any one in L-type wave filter, LC mode filter or LCL type wave filter；
Described local load (6) including: the three-phase symmetrical passive load of random capacity and connected mode.
The quick, intelligent anti-island method with electric network fault self-healing ability the most according to claim 5, its feature exists
In, described step 2 includes: add appropriate phase angle shift (12) to the electric network voltage phase angle that phaselocked loop (11) locks,
And the synchronized link (14) in cutting-in control circuit, wherein, the size of phase angle shift (12) must be according to control
The switching frequency of circuit processed and and the requirement of network electric energy quality adjust；Phase angle shift (12) is the least, and network electric energy quality
The highest, but the speed of isolated island detection is the slowest.
The quick, intelligent anti-island method with electric network fault self-healing ability the most according to claim 5, its feature exists
In, described step 3 includes:
Step 3.1: gather the voltage signal of points of common connection (5) in Grid-connected Distributed Generation Power System main circuit, and by locking
Phase ring obtains mains frequency signal；
Step 3.2: isolated island detecting step, the mains frequency signal i.e. obtained when phaselocked loop (11) is at time t0The most persistently surpass
When going out electrical network allowed band, i.e. judge that Grid-connected Distributed Generation Power System is in island operation state, starts anti-islanding protection；
Otherwise perform step 3.3；
Step 3.3: judge whether system meets and be in anti-islanding protection state, and points of common connection (5) place voltage magnitude
Absolute value is higher than threshold voltage UthAccumulated time reach time t1, when meeting, it is determined that electric network fault eliminates, solve
Except anti-islanding protection, recover to generate electricity by way of merging two or more grid systems；If being unsatisfactory for, then terminating, preparing to detect next time.
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