CN105914776B - Quick, intelligent anti-islanding system and method with electric network fault self-healing ability - Google Patents
Quick, intelligent anti-islanding system and method with electric network fault self-healing ability Download PDFInfo
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- CN105914776B CN105914776B CN201610226827.3A CN201610226827A CN105914776B CN 105914776 B CN105914776 B CN 105914776B CN 201610226827 A CN201610226827 A CN 201610226827A CN 105914776 B CN105914776 B CN 105914776B
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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
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- Supply And Distribution Of Alternating Current (AREA)
Abstract
The quick, intelligent anti-islanding system and method with electric network fault self-healing ability that the present invention provides a kind of, including step 1: building the main circuit of distributed generation grid-connected system；Step 2: disturbance module being deviated by Active phase and injects phase angle disturbance in the control circuit of grid-connected system；Step 3: by using the voltage signal of points of common connection in grid-connected system and the mains frequency signal obtained by phaselocked loop as foundation, realizing isolated island detection and electric network fault self-healing, the points of common connection refers to the position of grid-connected filter and local load access power grid.The present invention can quickly detect isolated island, to the distributed generation grid-connected system for realizing synchronized using phaselocked loop, not need to add the hardware such as any additional sensor；Under system locally extreme case of the load for the RLC in parallel load to match with distributed generation system power, remains to rapidly and accurately detect island operation state, check frequency is not present, and running efficiency of system can be effectively improved.
Description
Technical field
The present invention relates to the anti-islanding protection fields of distributed generation grid-connected system, and in particular, to one kind has power grid
The quick, intelligent anti-islanding system and method for fault self-recovery ability.
Background technique
As fossil energy is increasingly exhausted, the new energy such as solar energy, wind energy, fuel cell have obtained extensive exploitation and have made
With.These Distributed-generation equipments access power grid by power inverter, convey electric energy to power grid.For distributed generation grid-connected
System, there are this security risks of island effect.Island effect refers to, in distributed generation grid-connected system, when main power grid because
The phenomenon that after the reasons such as overhaul or break down are cut off, generating equipment continues to power to the load, and forms power supply isolated island.
Island effect cannot be such as timely detected out, then following danger can occur:
(1) due to being installed with auto recloser in network system, if electricity generation system does not have anti-islanding ability, very
It is possible that occur power generator and the nonsynchronous situation of power grid when system reclosing, and there may be very big dash current,
Circuit-breaker and power generator are damaged, or even power grid is caused to trip again；
(2) due under island state, system is detached from operation of power networks, is easy to appear voltage and frequency situation out of control.If
Power generator does not have voltage, frequency regulation capability, does not have anti-islanding ability yet and cuts out island state in time, it is likely that produces
Raw biggish voltage, frequency fluctuation, damage power grid and electrical equipment；
(3) when ground connection occurs for power grid or phase fault trips, island effect can interfere the removing of failure, Er Qiehui
Interfere the automatic or manual recovery of power grid；
(4) when power grid tripping maintenance, island effect can make the route disconnected with main power grid still charge, can be to maintenance personal
Safety generate threat.Therefore, when distributed generation grid-connected system is in island operation state, island state is detected in time
And anti-islanding protection movement is taken to be necessary.
The method of isolated island detection can be divided into passive detection and active detecting.Passive detection method is based on to voltage magnitude, phase
The abnormal monitoring such as position, frequency and harmonic components, such method are simple, it is easy to accomplish, but there are biggish check frequencies；Actively
Detection method is judged by applying specific offset or disturbance to power grid according to the reaction of power grid, such method can
Isolated island check frequency is effectively reduced, but method is more complex, usually to apply offset or disturbance to power grid, therefore can be to power grid quality
Generate adverse effect.Because check frequency will have a direct impact on the reliability of anti-islanding protection, using active detecting method
And reduce the feasible program that the influence to power grid quality is isolated island detection.
In addition, electric system has certain self-healing ability, for example, power grid there is transient fault after can pass through automatic reclosing
The equipment such as lock restore electricity.But existing anti-island method does not have self-healing ability, anti-lonely in distributed generation grid-connected system
After the movement of island, need that power grid can be accessed again after artificial judgment operates.Which not only adds distributed generation grid-connecteds
The maintenance workload of system, and reduce the operational efficiency and economic benefit of electricity generation system.It can be seen that having electric network fault self-healing
The intelligent anti-island method engineering practicability of ability is stronger, can more be adapted with smart grid and energy internet.
Summary of the invention
For the defects in the prior art, the object of the present invention is to provide a kind of with the quick of electric network fault self-healing ability
Intelligent anti-islanding system and method.
The quick, intelligent anti-islanding system with electric network fault self-healing ability provided according to the present invention, which is characterized in that
It include: Grid-connected Distributed Generation Power System main circuit, Active phase offset (APD) disturbance module and anti-islanding intelligent measurement mould
Block；
The Grid-connected Distributed Generation Power System main circuit includes: distributed generation resource, power inverter, grid-connected filter, sheet
Ground load and power grid；One end of the distributed generation resource is connected by power inverter with one end of grid-connected filter, described
The other end of grid-connected filter is connected through the first breaker with power grid, and local load is connected through the second breaker with power grid；Wherein
The position of grid-connected filter and local load access power grid is known as points of common connection (PCC)；
The Active phase offset disturbance module, acts in the control circuit of Grid-connected Distributed Generation Power System, cooperation is anti-
Isolated island intelligent detection module realizes the detection of active isolated island；Control circuit realizes distributed generation resource grid-connected current and electricity using phaselocked loop
The real-time synchronization of net voltage, the input quantity of phaselocked loop are to be converted through Clarke with the Grid-connected Distributed Generation Power System main circuit
The voltage of middle points of common connection, output quantity are the electric network voltage phase angle of locking and for the anti-islanding intelligent detection module
Mains frequency signal；The Active phase offset disturbance module is added suitable to the electric network voltage phase angle of phase lock loop locks
Phase angle shift, and for the synchronized link in cutting-in control circuit；
The anti-islanding intelligent detection module, for points of common connection in the Grid-connected Distributed Generation Power System main circuit
Voltage signal and the obtained mains frequency signal of phaselocked loop for according to realizing isolated island detection and electric network fault self-healing.
The distributed generation resource includes: photovoltaic battery array, fuel cell, battery, wind-powered electricity generation, appointing in diesel-driven generator
It is a kind of；And the type of the power inverter and distributed generation resource matches, wherein DC power supply corresponds to inverter, alternating current
Source corresponds to commutation inversion code converter；
The grid-connected filter includes: any one of L-type filter, LC mode filter or LCL type filter；
The local load includes: the three-phase symmetrical passive load of random capacity and connection type.
The Active phase offset disturbance module injects phase angle shift directly to grid voltage phase-angle, wherein phase angle shift
Size must be adjusted according to the switching frequency of control circuit and the simultaneously requirement of network electric energy quality；Phase angle shift is smaller, grid-connected electricity
Energy quality is higher, but the speed of isolated island detection is slower.
The anti-islanding intelligent detection module includes: isolated island detection module and electric network fault self-healing module,
The isolated island detection module works as lock for detecting whether Grid-connected Distributed Generation Power System is in island operation state
The mains frequency signal that phase ring obtains is in time t0Inside persistently (it is under 1547 standard of IEEE beyond power grid allowed band
49.3Hz~50.5Hz) when, i.e. judgement Grid-connected Distributed Generation Power System is in island operation state, starts anti-islanding protection；It is no
Then start electric network fault self-healing module；
The electric network fault self-healing module, for detecting whether Grid-connected Distributed Generation Power System needs to release anti-islanding protection
State, when Grid-connected Distributed Generation Power System is in anti-islanding protection state, and voltage magnitude absolute value is higher than at points of common connection
Threshold voltage UthAccumulated time reach time t1When, i.e. judgement electric network fault has been eliminated, and anti-islanding protection is released, and is restored grid-connected
Power generation；Otherwise electric network fault self-healing module is closed.
The quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention, including walk as follows
It is rapid:
Step 1: building the main circuit of distributed generation grid-connected system；
Step 2: disturbance module is deviated to control circuit injection phase angle disturbance from Active phase；
Step 3: the electricity obtained by the voltage signal and phaselocked loop of points of common connection in power grid system in a distributed manner
Net frequency signal is foundation, realizes isolated island detection and electric network fault self-healing, and the points of common connection refers to grid-connected filter and this
The position of ground load access power grid.
The Grid-connected Distributed Generation Power System main circuit built in step 1 includes: distributed generation resource, power inverter, grid-connected
Filter, local load and power grid；One end of the distributed generation resource passes through one end of power inverter and grid-connected filter
It is connected, the other end of the grid-connected filter is connected through the first breaker with power grid, and local load is through the second breaker and power grid
It is connected；Wherein the position of grid-connected filter and local load access power grid is known as points of common connection.
The distributed generation resource includes: photovoltaic battery array, fuel cell, battery, wind-powered electricity generation, appointing in diesel-driven generator
It is a kind of；And the type of the power inverter and distributed generation resource matches, wherein DC power supply corresponds to inverter, alternating current
Source corresponds to rectification-inversion code converter；
The grid-connected filter includes: any one of L-type filter, LC mode filter or LCL type filter；
The local load includes: the three-phase symmetrical passive load of random capacity and connection type.
The step 2 includes: suitable phase angle shift to be added to the electric network voltage phase angle of phase lock loop locks, and be used for simultaneously
Synchronized link in net control circuit, wherein the size of phase angle shift must be according to the switching frequency of control circuit and grid-connected
The requirement of power quality is adjusted；Phase angle shift is smaller, and network electric energy quality is higher, but the speed of isolated island detection is slower.
The step 3 includes:
Step 3.1: the voltage signal of points of common connection in the acquisition grid-connected main circuit of distributed generation resource, and obtained by phaselocked loop
Mains frequency signal；
Step 3.2: isolated island detecting step, i.e., the mains frequency signal obtained when phaselocked loop is in time t0Inside persistently beyond electricity
When net allowed band (being 49.3Hz~50.5Hz under 1547 standard of IEEE), i.e., decision-making system is in island operation state, opens
Dynamic anti-islanding protection；It is no to then follow the steps 3.3；
Step 3.3: judging whether Grid-connected Distributed Generation Power System meets in anti-islanding protection state, and points of common connection
Locate voltage magnitude absolute value and is higher than threshold voltage UthAccumulated time reach time t1, when meeting, determine that electric network fault has disappeared
It removes, releases anti-islanding protection, restore to generate electricity by way of merging two or more grid systems；If not satisfied, then terminating, preparation detects next time.
Compared with prior art, the present invention have it is following the utility model has the advantages that
1, the quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention can be examined quickly
Isolated island is measured, to the distributed generation grid-connected system for realizing synchronized using phaselocked loop, does not need to add any additional biography
The hardware such as sensor；Wherein, anti-islanding intelligent measurement algorithm is also very easy to accomplish, because mains frequency can be obtained directly by phaselocked loop
It arrives.
2, the quick, intelligent anti-islanding system with electric network fault self-healing ability provided according to the present invention, in system local
Under extreme case of the load for the RLC in parallel load to match with distributed generation system power, remain to rapidly and accurately detect
Check frequency is not present in island operation state out.
3, the quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention can be in isolated island
The state that electric network fault is eliminated rapidly and accurately is detected after protection act and recovery system generates electricity by way of merging two or more grid systems, and is occurred in power grid instantaneous
Under the similar situation such as failure and success automatic reclosing, the maintenance workload of distributed generation grid-connected system can be greatly reduced, had
Effect improves running efficiency of system.
Detailed description of the invention
Upon reading the detailed description of non-limiting embodiments with reference to the following drawings, other feature of the invention,
Objects and advantages will become more apparent upon:
Fig. 1 is the main circuit structure schematic diagram of distributed generation grid-connected system；
Fig. 2 is the implementation flow chart of anti-islanding intelligent measurement algorithm；
Fig. 3 is the realization block diagram that active phase offset (APD) disturbs module；
Fig. 4 is that active phase offset disturbs the grid-connected current waveform diagram after module injection disturbance；
Fig. 5 is the result figure that MATLAB environment Imitating electric network fault examines anti-islanding intelligent measurement algorithm validity.
In figure:
1- distributed generation resource；
2- power inverter；
The grid-connected filter of 3-；
The first breaker of 4-；
5- points of common connection (PCC)；
6- is locally loaded；
The second breaker of 7-；
8- power grid；
9- mains voltage signal；
10-Clarke transformation；
11- phaselocked loop；
12- phase angle shift；
13- adder；
Synchronized link in 14- cutting-in control circuit.
Specific embodiment
The present invention is described in detail combined with specific embodiments below.Following embodiment will be helpful to the technology of this field
Personnel further understand the present invention, but the invention is not limited in any way.It should be pointed out that the ordinary skill of this field
For personnel, without departing from the inventive concept of the premise, several changes and improvements can also be made.These belong to the present invention
Protection scope.
The present invention proposes a kind of quick, intelligent anti-island method with electric network fault self-healing ability, in the disturbance injected
Under the premise of having substantially no effect on power grid quality, the isolated operation shape of distributed generation grid-connected system can be rapidly and accurately detected
State, and after electric network fault is removed, have and automatically accesses the self-healing ability that power grid continues to generate electricity by way of merging two or more grid systems.It not only solves traditional anti-
Isolated island method is difficult to the problem of taking into account detection reliability and power grid quality, and effectively reduces non-self-cure type anti-island method band
The maintenance workload come, improves the operational efficiency and economic benefit of electricity generation system.
The quick, intelligent anti-island method with electric network fault self-healing ability provided according to the present invention includes distributed electrical
Source grid-connected system main circuit, Active phase offset (APD) disturbance method for implanting and anti-islanding intelligent measurement algorithm.
Wherein, Grid-connected Distributed Generation Power System main circuit includes distributed generation resource, power inverter, grid-connected filter, sheet
Ground load and power grid.Distributed generation resource can be the DC power supplies such as photovoltaic battery array, fuel cell, battery, be also possible to
The AC power sources such as wind-powered electricity generation, diesel-driven generator；Power inverter must match with power supply type, and DC power supply corresponds to inverter, hand over
Galvanic electricity source corresponds to rectification-inversion code converter；Grid-connected filter can use L-type, LC type or LCL type filter；Local load
It can be the three-phase symmetrical passive load of random capacity and connection type.Distributed generation resource is connected with power inverter, wherein straight
Galvanic electricity source uses two-wire connection type, and AC power source uses three-wire connection mode；Grid-connected filter one end and power inverter phase
Even, the other end is connected through breaker with power grid；Local load is connected through another breaker with power grid.Grid-connected filter is born with local
The position for carrying access power grid is known as points of common connection (PCC), and grid-connected voltage is in this point sampling.
Active phase offset disturbance method for implanting is in distributed generation grid-connected control circuit, to the electricity of phase lock loop locks
Suitable phase angle shift is added in net voltage phase angle, and it is synchronous with network voltage holding to obtain being used as grid-connected current in control circuit
Reference signal.It is characterized in that injecting phase angle shift directly to grid voltage phase-angle, it is inclined using active frequency to be different from existing palpus
The injection mode of (AFD) method of shifting, the advantage is that method is simpler, is also easier to adjust out satisfactory offset.
Wherein, the size of phase angle shift amount must be adjusted according to the switching frequency of control circuit and the simultaneously requirement of network electric energy quality；Phase angle
Offset is smaller, and network electric energy quality is higher, but the speed of isolated island detection is slower, so suitable offset should be chosen,
Not only meet the requirement of isolated island detection time, but also have substantially no effect on power grid quality；It is inclined that phase angle should suitably be reduced with switching frequency raising
Shifting amount.
Anti-islanding intelligent measurement algorithm mainly includes isolated island detection and electric network fault self-healing two parts.Isolated island detection criteria
Are as follows: whether the mains frequency signal obtained by phaselocked loop is in time t0Inside persistently (marked in IEEE 1547 beyond power grid allowed band
Lower standard is 49.3Hz~50.5Hz).If criterion meets, it is determined as island operation state, starts anti-islanding protection, otherwise enter
Electric network fault self-healing determines.Electric network fault self-healing criterion are as follows: whether system has been in anti-islanding protection state and points of common connection
Locate voltage magnitude absolute value and is higher than threshold voltage UthAccumulated time reach time t1.If criterion meets, electric network fault is determined
It has been eliminated that, release anti-islanding protection, restore to generate electricity by way of merging two or more grid systems, otherwise entered next round and detect.Time t0It preferably adjusts in Microsecond grade, both
It is able to satisfy the requirement of isolated island detection speed, and anti-islanding protection can be prevented because the reasons such as sampling singular value, system interference malfunction,
The specific time can be according to the requirement appropriate adjustment of loadtype and isolated island detection speed；Time t1It must be with threshold voltage UthMatch
It closes, when being determined with phase voltage, UthIt is preferably chosen in 300~310 ranges, at this time by time t1It adjusts in Microsecond grade, and
Suitably increase U with the reduction of load capacitythValue, while appropriate reduction time t1Setting valve, in this way can be quasi- in 0.1s
It really detects the state that electric network fault is eliminated and recovery is generated electricity by way of merging two or more grid systems, it is similar when being determined with line voltage.
The present invention includes the following steps:
Step S1: the main circuit of distributed generation grid-connected system is built；
Specifically, as shown in Figure 1, being the main circuit structure of distributed generation grid-connected system, including distributed generation resource 1, function
Rate converter 2, grid-connected filter 3, local load 6 and power grid 8.The distributed generation resource 1 connects power inverter by electric wire
2；Described 3 one end of grid-connected filter connects power inverter 2 by electric wire, and the other end is connected by electric wire with the first breaker 4
The points of common connection 5 with 8 direct connection of power grid is accessed afterwards；The local load 6 accessed after connect by electric wire with the second breaker 7 and
The points of common connection 5 of 8 direct connection of power grid.
Step S2: isolated island detection and electric network fault self-healing are realized using anti-islanding intelligent measurement algorithm；
Specifically, as shown in Figure 2, comprising:
Step S2.1: using the injection anti-islanding disturbance of Active phase offset method；Acquire the grid-connected main circuit of distributed generation resource
The voltage signal of middle points of common connection 5, and mains frequency signal is obtained by phaselocked loop；
Step S2.2: whether the mains frequency signal determining system obtained according to phaselocked loop is in island operation state.When
When system is without departing from power grid, since power generator capacity is much smaller compared with electrical network capacity, the phase angle disturbance of injection can't be to electricity
The generation of net phase significantly affects, and when next locking phase remains to be synchronized to grid phase；Once system is detached from power grid and is transported with island state
Row, then since distributed generation resource is the unique power supply of system, the phase angle disturbance of injection can obviously reflect the phase angle to next locking phase
On, and then positive feedback is formed, so that the offset of phase angle is increasing, to make system frequency deviate power grid power frequency, when frequency is inclined
Difference triggers anti-islanding protection beyond power grid allowed band.Isolated island detection criteria is set are as follows: the mains frequency obtained by phaselocked loop
Whether signal is in time t0Inside persistently beyond power grid allowed band (being 49.3Hz~50.5Hz under 1547 standard of IEEE).If
Criterion is set up, then is determined as island operation state, executes step S2.3, no to then follow the steps S2.4；
Step S2.3: anti-islanding protection movement is executed, step S2.6 is executed；
Step S2.4: electric network fault self-healing determine, after electric network fault is removed and is restored electricity, at PCC voltage magnitude and
Frequency will restore rapidly normal.Electric network fault self-healing criterion is set are as follows: whether system has been in anti-islanding protection state and public
Voltage magnitude absolute value is higher than threshold voltage U at tie pointthAccumulated time reach time t1If criterion is set up, electricity is determined
Net failure has been eliminated, and step S2.5 is executed；It is no to then follow the steps S2.6；
Step S2.5: releasing anti-islanding protection, restore to generate electricity by way of merging two or more grid systems, and executes step S2.6；
Step S2.6: epicycle anti-islanding detection terminates, and detects into next round.
In the step S2.1, the feature of Active phase offset disturbance method for implanting are as follows: as shown in figure 3, commonly connected
Mains voltage signal 9 is acquired at point 5, obtained voltage signal is sat by Clarke transformation 10 from three phase static after filtering processing
Mark system is converted into two-phase stationary coordinate system, by the two-way voltage signal under obtained two-phase stationary coordinate system by phaselocked loop 11 i.e.
Grid voltage phase-angle θ ' and mains frequency the f for anti-islanding detection algorithm can be obtained；Pass through phase to grid voltage phase-angle θ '
Device 13 is added to inject the phase angle shift 12 appropriate benchmark phase angle signal θ synchronous with power grid holding as grid-connected system.Wherein, phase angle
The size of offset 12 must be adjusted according to the switching frequency of control circuit and the simultaneously requirement of network electric energy quality；Phase angle shift 12 is got over
It is small, and network electric energy quality is higher, but the speed of isolated island detection is slower, so suitable phase angle shift 12 should be chosen, it can
Meet the requirement of isolated island detection time, and has substantially no effect on power grid quality；Phase angle shift can suitably be reduced with switching frequency raising
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 energy and voltage as seen from the figure
It is basic to keep further doing the injection of phase angle shift known to harmonic wave and Power Factor Analysis not with mutually and in good sinusoidal waveform
The harmonic wave for increasing system power, can only be such that power factor is declined slightly, but still 99% or more.
The setting method of parameter involved in the step S2 are as follows: time t0It preferably adjusts in Microsecond grade, had both been able to satisfy isolated island inspection
The requirement for degree of testing the speed, and anti-islanding protection can be prevented because of the reasons malfunction such as sampling singular value, system interference, the specific time can root
According to the requirement appropriate adjustment of loadtype and isolated island detection speed；Time t1It must be with threshold voltage UthIt matches, when with phase voltage
Determine and when power grid specified phase voltage virtual value is 220V, UthIt is preferably chosen in 300~310 ranges, at this time by time t1
Adjusting suitably increases U in Microsecond grade, and with the reduction of load capacitythValue, while appropriate reduction time t1Setting valve, in this way
The state that electric network fault is eliminated can be accurately detected in 0.1s and recovery is generated electricity by way of merging two or more grid systems.
Further, it when the RLC in parallel load that distributed generation grid-connected system access matches with the system power, bears
When load resonance frequency is power frequency 50Hz；Parameter tuning is t0=1ms, t1=1ms, Uth=310V；Simulating grid transient fault is simultaneously
Automatic reclosing, when system starts 0.1s, automatic reclosing is successful because of failure power-off, and when 0.25s for power grid, power system restoration
Power supply.As a result as shown in figure 5, during 0~0.1s, power grid and distributed generation grid-connected system are normal, although with active phase
Position offset method is filled with anti-islanding disturbance, but the mains frequency that phaselocked loop measures is stable always in power frequency 50Hz；In 0.1s wink
Between grid collapses power off, distributed generation system enters island operation state, since to become system unique for distributed generation resource
Power supply, disturbed using the anti-islanding of Active phase offset method injection so that system frequency deviates rapidly power grid power frequency, when frequency
The movement of triggering anti-islanding protection, isolated island detection time then need to be only much smaller than less than 55ms when rate deviation meets isolated island detection criteria
Time as defined in ieee standard 1547；After anti-islanding protection movement, voltage is reduced to rapidly zero at PCC, but due to by loading
The influence of resonance and phaselocked loop feedforward compensation (to accelerate locking phase speed), phase-lock-ring output frequency can in short-term vibrate after to
Power frequency convergence, it is 0.15s, i.e. most short reaction time as defined in power grid that this example, which takes the automatic reclosing reaction time, can preferably be examined
Examine the self-healing ability of anti-islanding intelligent measurement algorithm；It powering in 0.25s moment power system restoration, voltage is gradually recovered normally at PCC,
When voltage magnitude and frequency meet electric network fault self-healing criterion, distributed generation system releases anti-islanding protection, restores grid-connected
Power generation, the reaction time only need to be less than 0.04s.
The result of embodiment demonstrates quick, intelligent anti-island method proposed by the invention, can be in the disturbance injected
Under the premise of having substantially no effect on grid power quality, the isolated operation shape of distributed generation grid-connected system is rapidly and accurately detected
State, and after electric network fault is eliminated, have and automatically accesses the self-healing ability that power grid continues to generate electricity by way of merging two or more grid systems.
Specific embodiments of the present invention are described above.It is to be appreciated that the invention is not limited to above-mentioned
Particular implementation, those skilled in the art can make a variety of changes or modify within the scope of the claims, this not shadow
Ring substantive content of the invention.In the absence of conflict, the feature in embodiments herein and embodiment can any phase
Mutually combination.
Claims (7)
1. a kind of quick, intelligent anti-islanding system with electric network fault self-healing ability characterized by comprising distributed generation resource
Grid-connected system main circuit, Active phase offset disturbance module and anti-islanding intelligent detection module；
The Grid-connected Distributed Generation Power System main circuit includes: distributed generation resource (1), power inverter (2), grid-connected filter
(3), local load (6) and power grid (8)；One end of the distributed generation resource (1) passes through power inverter (2) and grid-connected filtering
One end of device (3) is connected, and the other end of the grid-connected filter (3) is connected through the first breaker (4) with power grid (8), local negative
Load is connected through the second breaker (7) with power grid (8)；The wherein position of grid-connected filter (3) and local load (6) access power grid (8)
Set referred to as points of common connection (5)；
The Active phase offset disturbance module, acts in the control circuit of Grid-connected Distributed Generation Power System, cooperates anti-islanding
Intelligent detection module realizes the detection of active isolated island；
The anti-islanding intelligent detection module, for points of common connection (5) in the Grid-connected Distributed Generation Power System main circuit
Voltage signal and the obtained mains frequency signal of phaselocked loop (11) for according to realizing isolated island detection and electric network fault self-healing；
Wherein, the anti-islanding intelligent detection module includes: isolated island detection module and electric network fault self-healing module；
The isolated island detection module works as phaselocked loop for detecting whether Grid-connected Distributed Generation Power System is in island operation state
(11) the mains frequency signal obtained is in time t0When inside persistently exceeding power grid allowed band, that is, determine the grid-connected system of distributed generation resource
System is in island operation state, starts anti-islanding protection；Otherwise start electric network fault self-healing module；
The electric network fault self-healing module, for detecting whether Grid-connected Distributed Generation Power System needs to release anti-islanding protection shape
State, when Grid-connected Distributed Generation Power System is in anti-islanding protection state, and voltage magnitude absolute value is higher than at points of common connection (5)
Threshold voltage UthAccumulated time reach time t1When, i.e. judgement electric network fault has been eliminated, and anti-islanding protection is released, and is restored grid-connected
Power generation；Otherwise electric network fault self-healing module is closed.
2. the quick, intelligent anti-islanding system according to claim 1 with electric network fault self-healing ability, which is characterized in that
The distributed generation resource (1) includes: photovoltaic battery array, fuel cell, battery, wind-powered electricity generation, appointing in diesel-driven generator
It is a kind of；And the power inverter (2) and the type of distributed generation resource (1) match, wherein DC power supply corresponds to inverter,
AC power source corresponds to commutation inversion code converter；
The grid-connected filter (3) includes: any one of L-type filter, LC mode filter or LCL type filter；
The local load (6) includes: the three-phase symmetrical passive load of random capacity and connection type.
3. the quick, intelligent anti-islanding system according to claim 1 with electric network fault self-healing ability, which is characterized in that
The Active phase offset disturbance module injects phase angle shift (12) directly to grid voltage phase-angle, wherein phase angle shift (12)
Size must be adjusted according to the switching frequency of control circuit and the simultaneously requirement of network electric energy quality；Phase angle shift (12) is smaller, and
Network electric energy quality is higher, but the speed of isolated island detection is slower.
4. a kind of quick, intelligent anti-island method with electric network fault self-healing ability, which comprises the steps of:
Step 1: building the main circuit of distributed generation grid-connected system；
Step 2: disturbance module is deviated to control circuit injection phase angle disturbance from Active phase；
Step 3: being obtained by the voltage signal and phaselocked loop (11) of points of common connection (5) in power grid system in a distributed manner
Mains frequency signal is foundation, realizes that isolated island detection and electric network fault self-healing, the points of common connection (5) refer to grid-connected filter
(3) and locally the position of (6) access power grid (8) is loaded；
Wherein, the step 3 includes:
Step 3.1: the voltage signal of points of common connection (5) in acquisition Grid-connected Distributed Generation Power System main circuit, and by phaselocked loop
Obtain mains frequency signal；
Step 3.2: isolated island detecting step, i.e., the mains frequency signal obtained when phaselocked loop (11) is in time t0Inside persistently beyond electricity
When net allowed band, i.e. judgement Grid-connected Distributed Generation Power System is in island operation state, starts anti-islanding protection；Otherwise it executes
Step 3.3；
Step 3.3: judging whether system meets in anti-islanding protection state, and voltage magnitude is absolute at points of common connection (5)
Value is higher than threshold voltage UthAccumulated time reach time t1, when meeting, determine that electric network fault has been eliminated, release anti-islanding and protect
Shield, restores to generate electricity by way of merging two or more grid systems；If not satisfied, then terminating, preparation detects next time.
5. the quick, intelligent anti-island method according to claim 4 with electric network fault self-healing ability, which is characterized in that
The Grid-connected Distributed Generation Power System main circuit built in step 1 includes: distributed generation resource (1), power inverter (2), grid-connected filter
Wave device (3), local load (6) and power grid (8)；One end of the distributed generation resource (1) by power inverter (2) with it is grid-connected
One end of filter (3) is connected, and the other end of the grid-connected filter (3) is connected through the first breaker (4) with power grid (8), this
Ground load is connected through the second breaker (7) with power grid (8)；Wherein grid-connected filter (3) and local load (6) access power grid (8)
Position be known as points of common connection (5).
6. the quick, intelligent anti-island method according to claim 5 with electric network fault self-healing ability, which is characterized in that
The distributed generation resource (1) includes: photovoltaic battery array, fuel cell, battery, wind-powered electricity generation, appointing in diesel-driven generator
It is a kind of；And the power inverter (2) and the type of distributed generation resource (1) match, wherein DC power supply corresponds to inverter,
AC power source corresponds to commutation inversion code converter；
The grid-connected filter (3) includes: any one of L-type filter, LC mode filter or LCL type filter；
The local load (6) includes: the three-phase symmetrical passive load of random capacity and connection type.
7. the quick, intelligent anti-island method according to claim 4 with electric network fault self-healing ability, which is characterized in that
The step 2 includes: that suitable phase angle shift (12) is added in the electric network voltage phase angle locked to phaselocked loop (11), and is used for simultaneously
Synchronized link (14) in net control circuit, wherein the size of phase angle shift (12) must be according to the switch frequency of control circuit
The requirement of rate and simultaneously network electric energy quality is adjusted；Phase angle shift (12) is smaller, and network electric energy quality is higher, but the speed of isolated island detection
It spends slower.
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| CN107918082B (en) * | 2016-10-10 | 2021-01-15 | 中国电力科学研究院 | Island detection method for parallel operation of inverters |
| CN108280269B (en) * | 2018-01-04 | 2021-08-13 | 国网安徽省电力有限公司铜陵供电公司 | Hybrid island detection method based on combination of wavelet neural network and SMS |
| WO2019148391A1 (en) * | 2018-01-31 | 2019-08-08 | 西门子公司 | Power grid fault detection method and device with distributed energy resource |
| CN108918996A (en) * | 2018-06-19 | 2018-11-30 | 中国科学院电工研究所 | Island detection method for distributed photovoltaic power generation system |
| CN109375008B (en) * | 2018-10-09 | 2021-04-30 | 北京精密机电控制设备研究所 | Method for detecting working state of electromagnetic lock |
| CN111585341A (en) * | 2020-04-03 | 2020-08-25 | 国网浙江台州市椒江区供电有限公司 | Anti-islanding device of distributed power generation system |
| CN111987700B (en) * | 2020-08-19 | 2022-07-08 | 国网综合能源服务集团有限公司 | Comprehensive energy system type power distribution network fault recovery method based on two-stage optimization |
| CN113589079A (en) * | 2021-07-28 | 2021-11-02 | 广东电网有限责任公司 | Testing method of self-healing system of power distribution network, electronic equipment and storage medium |
| CN114280363B (en) * | 2021-09-27 | 2024-05-10 | 金风科技股份有限公司 | Power grid frequency detection method and device and power grid frequency adjustment method and device |
| CN115483709B (en) * | 2022-10-17 | 2023-04-07 | 北京索英电气技术股份有限公司 | Island detection method and device of energy grid-connected system |
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