The content of the invention
System frequency modulation method is participated in the purpose of the present invention is to propose to a kind of variable-speed wind-power unit.
The purpose of the present invention is achieved through the following technical solutions:
The variable-speed wind-power unit that the present invention is provided participates in system frequency modulation method, comprises the following steps:
Wind turbine group be grouped and obtains each wind turbine packet;
The FREQUENCY CONTROL dead band of each wind turbine packet is set;
Obtain the system frequency excursion of each wind turbine packet;
Wind turbines FREQUENCY CONTROL is triggered when system frequency excursion overfrequency controlling dead error, mould is run into frequency modulation
Formula;
Calculate the frequency modulation increment and frequency modulated time sequential of each wind turbine packet;
Frequency modulation increment and frequency modulated time sequential are handed down to each wind turbine packet;
Judge whether the system frequency of each wind turbine packet crosses minimum point, if it is, wind turbine packet is exited into tune
Frequency operational mode;
If it is not, then carrying out frequency modulation according to frequency modulated time sequential runs up to end.
Further, the frequency modulation operational mode is carried out by being grouped collaboration frequency modulation control module, the packet association
Frequency modulation control module is provided with frequency modulation control target, the frequency modulation control target calculates participation frequency modulation mistake using below equation
Power increment maximum in journey:
Wherein, NiFor i-th group of Wind turbines number of units;ΔPWjThe active increment Delta P of frequency modulation is participated in for i-th group of Wind turbinesWj;
Further, the frequency modulated time sequential is determined in such a way:
1) determine to exit the frequency modulation operational mode time according to below equation for participating in the Wind turbines i and j of system frequency modulation:
Wherein:ζ is the maximum estimated value that region internal power disturbs that frequency touches the bottom after generation;Δtrec,kFor PW,k(t)
Recover to 0.95PW0,kRequired maximum time;
2) determine Wind turbines in Δ P according to below equationW,iThe lower maximum sustainable time Δ T of frequency modulation of effectmax,i:
ΔTMax, i≥tOff, i-ton;
Wherein, Δ Tmax,iFor the maximum sustainable time.
Further, frequency modulation post-set time toff,iWith active increment Delta PW,iSolved using section linear programming, specifically
Solution procedure is as follows:
Step 1:Wind turbine group is grouped according to wind speed;
Step 2:The decision variable of different grouping is determined, the decision variable includes Wind turbines under different wind speed and participates in adjusting
Frequency time and the active increment Delta P for exiting hopping patternW,i。
Step 3:Sectional linear programming seeks Δ PW,i;To each group blower fan Δ PW,iWith toff,iBetween relation piece-wise linearization,
And solved using sectional linear programming;
Step 4:To Δ PW,iRound downwards and obtain the power increment that Wind turbines participate in frequency-modulating process.
By adopting the above-described technical solution, the present invention has the advantage that:
Variable-speed wind-power unit that the present invention is provided participates in system frequency modulation method, by different type Wind turbines to system
The analysis of frequency stability, and combine Wind turbines input, the changing rule of power output, and Wind turbines fm capacity with
And frequency modulation terminate after rotating speed recovery process, it is proposed that wind power plant participate in system frequency modulation SECO strategy;Refer in the strategy
Lead down, can according to residing for Wind turbines in wind power plant wind speed environments difference, the Wind turbines in wind power plant are grouped, and
Sequence is quantified to the fm capacity of each group Wind turbines, coordinates the active increment of frequency modulation of each group Wind turbines and exits sequential,
Ensure on the basis of variable-speed wind-power unit safety stable operation, fully excavate the potentiality that variable-speed wind-power unit participates in system frequency modulation, together
When, Wind turbines, which are exited, also to be effectively reduced Wind turbines and exits negative effect of the frequency modulation operational mode to system frequency.
Other advantages, target and the feature of the present invention will be illustrated in the following description to a certain extent, and
And to a certain extent, based on will be apparent to those skilled in the art to investigating hereafter, Huo Zheke
To be instructed from the practice of the present invention.The present invention target and other advantages can be realized by following specification and
Obtain.
Embodiment 1
The variable-speed wind-power unit that the present embodiment is provided participates in system frequency modulation method, comprises the following steps:
Wind turbine group be grouped and obtains each wind turbine packet;
The FREQUENCY CONTROL dead band of each wind turbine packet is set;
Obtain the system frequency excursion of each wind turbine packet;
Wind turbines FREQUENCY CONTROL is triggered when system frequency excursion overfrequency controlling dead error, mould is run into frequency modulation
Formula;
Calculate the frequency modulation increment and frequency modulated time sequential of each wind turbine packet;
Frequency modulation increment and frequency modulated time sequential are handed down to each wind turbine packet;
Judge whether the system frequency of each wind turbine packet crosses minimum point, if it is, wind turbine packet is exited into tune
Frequency operational mode;
If it is not, then carrying out frequency modulation according to frequency modulated time sequential runs up to end.
The frequency modulation operational mode is carried out by being grouped collaboration frequency modulation control module, the packet collaboration frequency modulation control
Molding block is provided with frequency modulation control target, and the frequency modulation control target calculates power in participation frequency-modulating process using below equation
Maximum of increments:
Wherein, NiFor i-th group of Wind turbines number of units;ΔPWjThe active increment Delta P of frequency modulation is participated in for i-th group of Wind turbinesWj;
The frequency modulated time sequential is determined in such a way:
1) determine to exit the frequency modulation operational mode time according to below equation for participating in the Wind turbines i and j of system frequency modulation:
Wherein:ζ is the maximum estimated value that region internal power disturbs that frequency touches the bottom after generation;Δtrec,kFor PW,k(t)
Recover to 0.95PW0,kRequired maximum time;
2) determine Wind turbines in Δ P according to below equationW,iThe lower maximum sustainable time Δ T of frequency modulation of effectmax,i:
ΔTMax, i≥tOff, i-ton;
Wherein, Δ Tmax,iFor the maximum sustainable time.
Frequency modulation post-set time toff,iWith active increment Delta PW,iSolved, specifically solved using section linear programming
Journey is as follows:
Step 1:Wind turbine group is grouped according to wind speed;
Step 2:The decision variable of different grouping is determined, the decision variable includes Wind turbines under different wind speed and participates in adjusting
Frequency time and the active increment Delta P for exiting hopping patternW,i。
Step 3:Sectional linear programming seeks Δ PW,i;To each group blower fan Δ PW,iWith toff,iBetween relation piece-wise linearization,
And solved using sectional linear programming;
Step 4:To Δ PW,iRound downwards and obtain the power increment that Wind turbines participate in frequency-modulating process.
Embodiment 2
A kind of variable-speed wind-power unit that the present embodiment is provided participates in system frequency modulation method, it is adaptable to the grid-connected system of large-scale wind power
System;Wherein isolated between variable-speed wind-power unit rotor loop and power system by Wind turbines current converter, therefore, even if speed change
Wind turbines have with the comparable levels of inertia time constant of synchronous generator, be generally also difficult to response system frequency change, hair
Wave primary frequency modulation effect.
The Wind turbines frequency modulation control mode generally accepted at present, effectively can play it using the inertia of Wind turbines
Supporting role to system frequency, as shown in figure 1, Fig. 1, which is variable-speed wind-power unit, participates in system frequency modulation control principle;Wherein, PW
Electromagnetic power, ω are exported for Wind turbinesrefFor by PWThe rotor speed calculated, ω is Wind turbines rotor speed, Pref0
With Δ PWRespectively Wind turbines participate in the power increment in power output reference value and frequency-modulating process before frequency modulation, frequency modulation triggering
When selecting switch change to 2, T from 1WFor Wind turbines real power control responsive time constant, amplitude limit link effect is limitation wind turbine
Export electromagnetic power amplitude.
For wind power plant, each running of wind generating set situation, wind speed are different, in order to play a whole group of planes to greatest extent
Fm role, it is necessary to analyse in depth variable-speed wind-power unit participate in frequency-modulating process in initial wind speed, frequency modulated time, warble rate
Deng the relation of many factors, wind turbine group sequential coordination control strategy is designed.
The present embodiment is analyzed frequency modulation basic process first, specific as follows:Variable-speed wind-power unit normally operates in maximum work
Rate tracking mode.By taking 1.5MW double-fed variable-speed wind-power units as an example, Wind turbines rotating speed-power characteristic is as shown in Figure 2.Fig. 2
Power and rotation speed change relation in system frequency-modulating process are participated in for double-fed fan motor unit;, can according to the running status of Wind turbines
Wind speed is divided into 3 intervals:Low wind speed (<11.7m/s), middle wind speed (11.7~13m/s) and high wind speed (>13m/s);In figure,
PmaxFor Wind turbines maximum capture power under different wind speed;Respectively so that wind speed is 10m/s and 12m/s as an example, to variable-speed wind-power machine
Group participation system frequency-modulating process is analyzed, ton(t′on) and toff(t′off) it is respectively that Wind turbines participate in rising for system frequency modulation
Begin and post-set time, tofF(t′off)-ton(t′on) participate in the system frequency modulation duration for Wind turbines.Wind turbines are with rotor
The time that rotating speed is down to 0.7 (perunit value) is the maximum crash time for exiting frequency modulation operational mode.Variable-speed wind-power unit participates in system
Input mechanical output P in frequency-modulating process of unitingm(P′m) and PW(P′W) variation tendency as shown in phantom in Figure 2.
It can be seen that double-fed fan motor unit participates in changed power in system frequency-modulating process under low wind speed and middle wind speed
Trend is similar, and Wind turbines, which participate in system frequency modulation, can cause wind turbine under the decline of Wind turbines input power, but different wind speed
Group rotation speed change is different to the influence degree of Wind turbines input power, and the initial higher Wind turbines input power of wind speed is with rotating speed
Rate of change is bigger.
In fm capacity analysis in low wind speed band
Low wind speed is similar with middle wind speed leeward group of motors participation system frequency-modulating process, and the present embodiment is to low wind speed and middle wind speed
The fm capacity of lower double-fed fan motor unit is analyzed in the lump.Under low wind speed and middle wind speed, variable-speed wind-power unit participates in system and adjusted
Maximal power tracing state is in before frequency, Wind turbines rotor speed during power support is provided for system can decline, wind
The wind power efficiency of group of motors reduces with the reduction of rotating speed, and corresponding Wind turbines capture wind power can also reduce.If
When system frequency is by f0Drop to f1, variable-speed wind-power unit Chirp controller action, as shown in figure 3, Wind turbines power output
Operating point variation track be A → B → C → E → F, corresponding input power operating point variation track be A → D → F, figure midpoint A,
B, C, D position connotation are consistent with Fig. 6-8, and D (E) → F is Wind turbines rotating speed Restoration stage.Fig. 3 is middle wind speed and low wind speed
Lower Wind turbines participate in the changed power curve in system frequency-modulating process.
As shown in Figure 2, ω of the Wind turbines rotor speed from A points0Drop to the ω of D points1, it is total that Wind turbines rotor discharges
Kinetic energy E is:The total kinetic energy of rotor release corresponds to the area in ABCD regions in Fig. 3, and Wind turbines are real
The power of border additional issue is Pw0Above section (S in figure1It is shown), then S1=Δ Pw(toff-ton) bigger, Wind turbines are adjusted to system
The contribution of frequency is bigger, can be defined as effectively discharging kinetic energy;Another part kinetic energy is PW0Following part, the S in figure2Institute
Show, area isThe part kinetic energy is used for compensating the wind power efficiency caused by rotating speed declines and dropped
Wind energy loss caused by low, the part kinetic energy may be defined as kinetic energy loss.
Based on above-mentioned analysis, 1.5MW variable speed DFIG frequency modulation Relationship of Related Factors is calculated as shown in Figure 4.Figure
In, abscissa is that double-fed fan motor unit participates in active output increment Δ P in system frequency-modulating processW;Ordinate is joined for Wind turbines
With the maximum sustainable time Δ T of system frequency modulationmax.Double-fed fan motor unit initial speed is 0.7 (perunit when wind speed is less than 6.7m/s
Value), do not possess fm capacity.Fig. 4 is 1.5MW double-fed fan motor unit frequency modulation sustainable times and power under middle wind speed and low wind speed
The quantization schematic diagram of increment.
From fig. 4, it can be seen that on the basis of equal-wattage increment, with the increase of wind speed, Wind turbines frequency modulation is sustainable
Time is in downward trend after first rising.In low wind speed band, Wind turbines participate in system fm capacity and increase with wind speed and increase
By force, reason is Wind turbines rotor initial speed and can effectively discharge kinetic energy and constantly increase with the increase of wind speed.In apoplexy
In speed belt, Wind turbines participate in system fm capacity and increase with wind speed and weaken, and are due to that Wind turbines turn in the wind speed band
Speed is constant, so that the releasable total kinetic energy of Wind turbines institute keeps constant, constantly increases on the contrary for compensating kinetic energy loss part.
Therefore, corresponding effectively release kinetic energy constantly reduces, and causes participation system fm capacity to weaken.
Wind turbines, which participate in the rotating speed Restoration stage power output after system frequency modulation terminates, can be less than initial power.Wind speed point
Not Wei 7,8,9,10,11,12,13m/s when, Wind turbines power output is recovered (to return to 0.95P substantiallyW0) required time
ΔTrecRespectively 0.2,1.3,1.9,2.1,2.4,2.5,1.8s.ΔTrec=t 'end-toff, wherein t 'endIt is defeated for Wind turbines
At the time of going out power recovery 95%.
Fm capacity is analyzed in high wind speed band:In high wind speed band, variable-speed wind-power unit is in rated power and exports operation
Can state, participate in frequency modulation, depending on factors such as Wind turbines transverter short-time overload capacities, it is generally recognized that Wind turbines can be short
Shi Zengfa 20% rated power.In the output upper limit, Wind turbines increase the wind power of capture by reducing propeller pitch angle, tool
There are the active enabling capabilities more more longlasting than middle wind speed and low wind speed.It is defeated during variable-speed wind-power unit participation system frequency modulation under high wind speed
Enter, power output change procedure it is as shown in Figure 5.If when system frequency is by f0Drop to f1When, variable-speed wind-power unit participates in system and adjusted
Frequently, mechanical output operating point variation track is A → D → C → E, and electromagnetic power output operating point variation track is A → B → C → E.
Rotor speed is influenceed by propeller pitch angle adjustment is delayed, from A points change to D point process in be declined slightly and fluctuate, to then base during D points
Originally maximum (top) speed 1.2p.u. is returned to.Fig. 5 participates in the changed power in system frequency-modulating process for variable-speed wind-power unit under high wind speed
Curve.
Wind power plant sequential cooperates with frequency modulation control strategy:Under different wind speed variable-speed wind-power unit participate in system fm capacity have compared with
Big difference, if wind turbine group participates in frequency modulation in the case of collaboration chirping strategies are lacked, is likely to result in a part of wind turbine
Group is shut down caused by excessive frequency modulation, and another part Wind turbines fm capacity is not in full use.
Meanwhile, the main purpose that variable-speed wind-power unit participates in system frequency modulation is to reduce transient frequency to fall, and Wind turbines
The releasable kinetic energy of rotor inertia link is limited, therefore, and system frequency, which crosses Wind turbines after minimum point, just to be needed actively to exit
Frequency modulation operational mode.To avoid Wind turbines while exiting frequency modulation operational mode causes larger secondary pulse to system frequency,
Need to coordinate the sequential that each Wind turbines of control exit frequency modulation operation in the range of wind power plant.Analyzed based on more than, propose wind-powered electricity generation
Field internal speed-changing wind turbine group participates in system frequency modulation SECO strategy.The strategy comprising wind turbine group frequency modulation intervention control and
Wind turbine group frequency modulation SECO, control each Wind turbines of wind power plant are with the tune of wind speed-active increment-sustainable time dependence
Frequency intervention participates in frequency-modulating process with escape mechanism, and its principle is as shown in Figure 6.In figure, frefFor system nominal frequency, fgridTo be
System practical frequency.
Fig. 6 is that wind power plant participates in system frequency modulation control strategy;Wind turbine group frequency modulation intervention control action mechanism is, when being
Wind turbines FREQUENCY CONTROL is triggered during system frequency shift (FS) overfrequency controlling dead error, the Wind turbines with fm capacity, which enter, to be adjusted
Frequency operational mode.The SECO of wind turbine group frequency modulation controls 2 moulds comprising packet collaboration frequency modulation control, frequency modulation incremental distribution
Block.Packet collaboration frequency modulation control module is responsible for the packet of wind turbine group, and cooperates with the frequency modulation amount of each Wind turbines and exit
Sequential;Frequency modulation incremental distribution control module is responsible for instruction being handed down to each Wind turbines.In Fig. 6, Δ PWjWith Δ TiRespectively i-th
Group Wind turbines participate in the active increment and frequency modulated time of frequency modulation.
Being grouped the control targe of collaboration frequency modulation control module is, the wind speed relied in consideration Wind turbines frequency modulation-active
On the basis of increment-sustainable time factor, to play the maximum fm capacity of wind turbine group as target, while reducing wind-powered electricity generation as far as possible
Adverse effect when unit is exited.Its target maximizes to participate in power increment in frequency-modulating process:Wherein
NiFor i-th group of Wind turbines number of units.
Constraints is as follows:
1) for participating in any 2 groups of Wind turbines i and j of system frequency modulation, exiting the frequency modulation operational mode time should meet:
Wherein:The maximum estimated value that frequency touches the bottom after ζ occurs for power disturbance (in region);Δtrec,kFor PW,k
(t), recover to 0.95PW0,kRequired maximum time.
2) Wind turbines are in Δ PW,iThe effect lower frequency modulation maximum sustainable time is Δ Tmax,i, should meet:ΔTmax,i≥
toff,i-ton.Wherein:ΔTmax,iCan be according to Δ PW, iThe quantization of frequency modulation sustainable time and power increment exemplified by reference picture 4 refer to
Mark is obtained.
Above-mentioned model is related to 2 groups of variable toff,iWith Δ PW,i, wherein toff,iBy Δ PW,iDetermine, Δ Tmax,iWith Δ PW,iBetween
For non-linear relation, the present embodiment carries out piece-wise linearization to it.Fig. 4 middle polylines A-B-C-D is t under 12m/s wind speedoff,iWith Δ
PW,iBetween relation piece-wise linearization result, also need to make similar process under other wind speed.The present embodiment uses section linear programming
Solve, solution procedure is as follows.
Step 1:Wind turbine group is grouped
It is not generally integer value that wind speed is surveyed at each Wind turbines rotating shaft, and there is error, convenient for processing, and ensures one
Fixed margin of safety, is handled using the discrete mode that rounds wind speed:Wind speed is rounded downwards under low wind speed, and middle wind speed leeward speed is upwards
Round;Wind turbines can lift power output by improving capture wind energy under high wind speed, and fm capacity does not change with wind speed, is classified as
One group.
Step 2:Determine decision variable
It is different from middle wind speed and low wind speed from above analyzing, under high wind speed Wind turbines participate in frequency modulated time not by
Limitation, may be selected finally to exit hopping pattern, corresponding Δ PW,iTake 0.1 (perunit value);Wind speed be less than 7m/s when Wind turbines not
Possess fm capacity, be not involved in frequency modulation.Wind turbines Δ P under remaining wind speedW,iAs decision variable, span is 0~
0.1, take zero expression to be not involved in frequency modulation.
Step 3:Sectional linear programming seeks Δ PW,i
To each group blower fan Δ PW,iWith toff,iBetween relation piece-wise linearization, and using sectional linear programming solve.Step
4:To the Δ P drawn in step 3W,iRound downwards and (relative to the power increment in Fig. 4, that is, retain 2 decimals), obtain final
Wind turbines participate in frequency-modulating process power increment.
In real system application, if the time delay of wind speed information collection and transmission takes 0.5s, through measuring and calculating, 60 typhoons
The system of group of motors scale formulates the total time of primary frequency modulation control decision within 0.6s.In order to application in real time, collaboration
Control module real-time circulation gathers the wind speed information for controlling wind turbine group, and updates control strategy immediately.When system deviation is super
When crossing threshold value, triggering command is sent by wind turbine group frequency modulation intervention control module, Collaborative Control module can be according to newest
Control strategy no-delay send control instruction.Thus, each Wind turbines can intervene frequency modulation in the very first time simultaneously.
The present embodiment is emulated according to the region of four machine two;Calculation as shown in Figure 7 has been built in MATLAB/Simulink
Example system.Wherein G1 to G3 is synchronous machine, and total capacity is 900MW;Generator is replaced with wind power plant at No. 4 nodes, wind power plant by
60 1.5MW double-fed fan motor units compositions.If whole Wind turbines both participate in system frequency modulation, per typhoon group of motors wind speed it is high,
In, grab sample in low wind speed band.The active output upper limit of Wind turbines is 1.1 (perunit values);Load 1 and 2 be respectively 600MW and
K is switched at 30MW, load 2 and is initially disconnection, Wind turbines FREQUENCY CONTROL dead band is 0.2Hz.
Fig. 7 is the test system containing wind power plant;Wind power plant Collaborative Control module reads each Wind turbines wind by the cycle of 10s
Fast data, generate frequency modulation control strategy.After emulation starts, air speed data is read, wind speed collection, transmission delay take 0.5s, passed through
0.52s generates wind turbine group frequency modulation control strategy:Wind turbines in wind power plant can be divided into 6 by wind turbine group wind speed after rounding
Group (W1 to W6), wind speed and each group Wind turbines number of units after rounding, and each group Wind turbines frequency modulation participate in time and frequency modulation
During power increment it is as shown in table 1.The wind-powered electricity generation field coordination frequency modulation control strategy of table 1
Wind turbines |
W1 |
W2 |
W3 |
W4 |
W5 |
W6 |
Wind speed/(m/s) |
≤7 |
8 |
9 |
11 |
12 |
≥15 |
Wind turbines number of units |
8 |
11 |
11 |
9 |
8 |
13 |
ΔT/(s) |
0 |
8.5 |
9.8 |
11.7 |
6 |
14.1 |
ΔPW/(p.u.) |
0 |
0.01 |
0.01 |
0.02 |
0.07 |
0.1 |
If system original frequency is 50Hz, closure switch K during 2s, sudden load increase 30MW, frequency decrease beyond door during 3.2s
Threshold value, wind power plant participates in frequency modulation by the preceding frequency modulation control policy control each group Wind turbines once generated (during 0.52s), according to mesh
Offer of tender numerical expression, target function value is 0.96.Change is smaller in the wind speed short time, and wind speed rounds processing certain nargin, because
This, wind turbine group is participated in can temporary blocking control system in frequency-modulating process.Participated in after wind turbine group after frequency modulation terminates again
Air speed data is gathered, new frequency modulation control strategy is generated, and is refreshed by the cycle of 10s, wind power plant frequency modulation control module is again
Wind turbine group is controlled to participate in system frequency modulation according to the control strategy of last time generation during secondary triggering.
Wind speed is less than 7m/s at W1, is not involved in frequency modulation, and remaining 5 groups of Wind turbines power outputs and capture wind changed power are bent
Line is as shown in Figure 8.Fig. 9 show the system frequency response curve before and after Wind turbines participation system frequency modulation;Fig. 8 is each group wind-powered electricity generation
Unit participates in the changed power curve in system frequency-modulating process;Fig. 9 is the system frequency in the case of Wind turbines participation system frequency modulation
Rate response curve 1;From fig. 9, it can be seen that Wind turbines participate in the range of decrease value that the lower rate of disturbance is obviously reduced in system frequency modulation, it can see
Go out Wind turbines to participate in system frequency modulation the range of decrease value of the lower rate of disturbance is obviously reduced improving system frequency stability;Wind turbine component
Although can occur small size wave height system frequency stability during exiting allocation and transportation row mode;Wind turbine component exits allocation and transportation row mould
Although small size wave height system frequency stability can occur during formula;Although wind turbine component is exited during allocation and transportation row mode
Can occur small size wave height system frequency stability;Although during exiting allocation and transportation row mode small amplitude wave can occur for wind turbine component
High system frequency stability;Although during exiting allocation and transportation row mode small size wave height system frequency can occur for wind turbine component
Stability;Although during exiting allocation and transportation row mode fuctuation within a narrow range can occur for wind turbine component, to system frequency stability shadow
Ring little.
Emulated below according to Ji NORTEL net:Wherein, (wherein thermoelectricity accounts for that (wherein thermoelectricity is accounted for total installation of generating capacity 24840MW
62.1%, wind-powered electricity generation accounts for 34.3%, and water power accounts for 1.7%, and solar energy and storage are accounted for, and 1.9%) solar energy and storage account for, Ji Bei companies O&M
23,500kV transformer stations, capacity 48830MVA, circuit 9981km;105,220kV transformer stations;Power transformation capacity 41160MVA, line
Road 8629km.Shadow of the wind-electricity integration to system frequency stability is analyzed by taking Ji Bei Zhangjiakou power network certain method of operation in 2013 as an example
Ring.Zhangjiakou power network peak load about 1.77GW, frequency modulation is cooperateed with using Zhangjiakou wind power plant (capacity is about 150MW) as participation
The wind power plant of control.Simulation time is 45s, it is assumed that wind speed keeps constant at load and each blower fan in simulation process, and emulation starts
2s increases 50MW loads, and simulation result is as shown in Figure 10.Figure 10 is the system frequency in the case of Wind turbines participation system frequency modulation
Rate response curve 2;It can be seen that under same power disturbance, after the grid-connected replacement part conventional power unit of large-scale wind power
System frequency deviation is significantly increased, and reason is that Wind turbines replacement part conventional power unit reduces system rotary inertia and system
Fm capacity.Wind power plant is participated in the case of system frequency control, and system frequency stability is obviously improved, maximum frequency deviation and nothing
It is more or less the same in the case of wind-electricity integration.
The present embodiment comparative analysis influences of the different type Wind turbines to system frequency stability, and with double-fed speed change
Influence of the wind-electricity integration to system frequency stability under different wind speed environments and different permeabilities is analyzed exemplified by Wind turbines, is ground
Study carefully and participated in without variable-speed wind-power unit under spare condition in frequency-modulating process, Wind turbines input, the changing rule of power output, and
Rotating speed recovery process after terminating to Wind turbines fm capacity and frequency modulation has carried out quantitative analysis, and wind power plant is proposed accordingly
The SECO strategy of participation system frequency modulation.Under the strategy instruction, can according to residing for Wind turbines in wind power plant wind speed environments
Difference, the Wind turbines in wind power plant are grouped, and the fm capacities of each group Wind turbines is quantified to sort.In this base
On plinth, coordinate the active increment of frequency modulation of each group Wind turbines and exit sequential, ensure variable-speed wind-power unit safety stable operation
On the basis of, the potentiality that variable-speed wind-power unit participates in system frequency modulation are fully excavated, meanwhile, Wind turbines, which are exited, also effectively reduces wind
Group of motors exits negative effect of the frequency modulation operational mode to system frequency.
Finally illustrate, the above embodiments are merely illustrative of the technical solutions of the present invention and it is unrestricted, although with reference to compared with
The present invention is described in detail good embodiment, it will be understood by those within the art that, can be to skill of the invention
Art scheme is modified or equivalent substitution, and without departing from the objective and scope of the technical program, it all should cover in the present invention
Protection domain among.