CN112271760A - Frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection - Google Patents
Frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection Download PDFInfo
- Publication number
- CN112271760A CN112271760A CN202011216099.0A CN202011216099A CN112271760A CN 112271760 A CN112271760 A CN 112271760A CN 202011216099 A CN202011216099 A CN 202011216099A CN 112271760 A CN112271760 A CN 112271760A
- Authority
- CN
- China
- Prior art keywords
- direct
- wind turbine
- turbine generator
- drive wind
- frequency modulation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 38
- 230000003044 adaptive effect Effects 0.000 claims abstract description 25
- 230000008859 change Effects 0.000 claims description 12
- 238000004458 analytical method Methods 0.000 abstract description 2
- 238000011217 control strategy Methods 0.000 description 17
- 230000004044 response Effects 0.000 description 15
- 238000010586 diagram Methods 0.000 description 6
- 230000001360 synchronised effect Effects 0.000 description 6
- 238000004088 simulation Methods 0.000 description 4
- 238000012795 verification Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 239000013256 coordination polymer Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 238000001342 constant potential amperometry Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- 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
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/48—Controlling the sharing of the in-phase component
-
- 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
-
- 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
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Eletrric Generators (AREA)
Abstract
A frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection relates to the technical field of power system analysis control. The problem that the frequency modulation capability of the wind turbine generator cannot be fully exerted when a fixed coefficient is adopted when the wind turbine generator participates in frequency modulation by adopting a rotor inertia control method is solved. Firstly, calculating a virtual inertia time constant H of a direct-drive wind turbine generator in different running states; then, calculating the self-adaptive droop frequency modulation coefficient K of the direct-drive wind turbine generator according to the virtual inertia time constant HpAnd adaptive virtual inertia coefficient Kd(ii) a Finally, obtaining an additional active power reference value delta P of the direct-drive wind turbine generator participating in frequency modulation control; enabling the delta P and the maximum power tracking instruction value P of the direct-drive wind turbine generatorMPPTSuperposing, obtaining the active power reference value P after superpositionrefSending the power to a converter control system of the direct-drive wind turbine generator, and controlling the output power of the direct-drive wind turbine generator by the control system so as to realize the control of the output power of the direct-drive wind turbine generatorAdjusting the frequency of the power grid; the method is mainly applied to the field of wind power grid-connected frequency modulation control.
Description
Technical Field
The invention relates to the technical field of analysis and control of power systems.
Background
In order to enable the wind turbine generator set to have frequency regulation capability like a conventional generator set, the frequency control method proposed at home and abroad mainly comprises rotor inertia control, power standby control and additional energy storage control.
The rotor inertia control mainly comprises virtual inertia control and droop control.
The principle of virtual inertia control is that a frequency control link is added in an active power control system of a wind turbine generator to generate equivalent inertia which is the same as that of a conventional generator. When the frequency of the power system changes, the kinetic energy on the rotor is absorbed or released through an additional frequency control link, so that the frequency adjustment of the system is realized. In the recovery process of the rotating speed, the method can absorb or release energy, so that impact is caused to a power grid, and secondary reduction of the frequency of a power system is easily caused.
Droop control is similar to a speed regulating device in a traditional synchronous generator, a power-frequency characteristic curve of the synchronous generator is simulated, frequency deviation of a system is used as an input signal, through a proportional amplification link, output variable quantity is added to an original active power reference value, active power output of the wind turbine generator is adjusted, the traditional droop control adopts a fixed droop control coefficient in a full wind speed working interval of the wind turbine generator, and the frequency modulation capacity of the wind turbine generator cannot be effectively exerted.
In summary, the following problems mainly exist in the wind power plant alternating current and direct current grid connection participation frequency modulation: when the wind turbine generator participates in frequency modulation by adopting a rotor inertia control method, the frequency modulation capability of the wind turbine generator cannot be fully exerted by adopting a fixed coefficient, the control coefficient cannot be changed in a self-adaptive mode according to different running states of the wind turbine generator, and the problems need to be solved urgently.
Disclosure of Invention
The invention aims to solve the problem that the frequency modulation capability of a wind turbine generator cannot be fully exerted when a fixed coefficient is adopted when the wind turbine generator participates in frequency modulation by adopting a rotor inertia control method, and provides a frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection.
The frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection comprises the following steps:
step one, calculating a virtual inertia time constant H of a direct-drive wind turbine generator in a corresponding operation state; the running states of the direct-drive wind turbine generator set comprise a starting area, a maximum wind energy tracking area and a constant rotating speed area;
step two, calculating the self-adaptive droop frequency modulation coefficient K of the direct-drive wind turbine generator according to the virtual inertia time constant H in the corresponding operation statepAnd adaptive virtual inertia coefficient Kd：
Step three, according to the frequency change rate of the system
System frequency deviation delta f and self-adaptive droop frequency modulation coefficient KpAnd adaptive virtual inertia coefficient KdCalculating to obtain an additional active power reference value delta P of the direct-drive wind turbine generator participating in frequency modulation control; and adding the reference value delta P and P of active powerMPPTPerforming superposition, and obtaining P after superpositionrefSending the power to a direct-drive wind turbine converter control system, and receiving the P by the direct-drive wind turbine converter control systemrefControlling the output power of the direct-drive wind turbine generator set so as to realize the adjustment of the power grid frequency;
PMPPTthe maximum power tracking instruction value is the maximum power tracking instruction value of the direct-drive wind turbine generator;
Prefis a power reference value of the direct-drive wind turbine generator.
Preferably, in the step one:
(1) when the direct-drive wind turbine generator runs in a starting area, H is equal to 0, and at the moment, w is not more than wMPPT_1；
(2) When the direct-drive wind turbine generator runs in the maximum wind energy tracking area,
at this time, wMPPT_1≤w＜1p.u.；
(3) When the direct-drive wind turbine generator runs in a constant rotating speed region,
at this time, w is 1 p.u.;
wherein w is the rotor speed;
wMPPT_1the initial rotating speed of the maximum wind energy tracking area of the direct-drive wind turbine generator set is obtained;
j is the rotational inertia of the direct-drive wind turbine generator;
w0is the initial value of the rotor speed;
wminis the minimum value of the rotor speed;
PNthe rated power of the direct-drive wind turbine generator is set;
ρ is the air density;
r is the radius of the fan;
v is the wind speed;
t1and t2Respectively the initial moment and the end moment of the change of the rotor speed;
t is the current running time;
Cp maxthe maximum wind energy utilization coefficient;
p is the number of pole pairs;
f is the system actual frequency.
Preferably, in the second step, the first step,
wherein, K1Is a reference differential coefficient;
K2is a reference scale factor.
Preferably, in step three,
the invention has the following beneficial effects: aiming at the problem that the rotor inertia control strategy with fixed coefficient can not fully exert the frequency modulation capability of the direct-drive wind turbine generator at different wind speeds, the invention provides the adaptive coefficient improved frequency modulation control strategy suitable for the alternating current grid connection of the wind power plant, wherein the adaptive coefficient improvement is mainly embodied in that the virtual inertia time constants H of the direct-drive wind turbine generator are different in value under different operating states, and the frequency modulation control coefficient (namely, the adaptive droop frequency modulation coefficient K) is adjusted in real time according to the direct-drive wind turbine generator under different operating statespAnd adaptive virtual inertia coefficient Kd) The purpose of calling the frequency modulation capability of the wind turbine generator to the maximum extent is achieved, and simulation results show that the adaptive frequency modulation control method based on the virtual inertia time constant H can effectively improve the frequency modulation capability of the wind turbine generator, enhance the stability of the system, and simultaneously avoid the problem that the system is unstable because a control coefficient cannot be selected too large when the wind turbine generator operates at a low wind speed.
Drawings
FIG. 1 is a flow chart of a frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection, provided by the invention;
FIG. 2 is a power characteristic curve of a direct-drive wind turbine; wherein pu is an abbreviation for p.u., which represents a per unit value;
FIG. 3 is a relation between a virtual inertia time constant H of the direct-drive wind turbine generator and a rotor speed w and an output power P';
FIG. 4 shows the frequency modulation coefficient K for adaptive drooppAnd adaptive virtual inertia coefficient KdA functional block diagram for control; wherein f isnomIs rated frequency, f is system actual frequency, w is rotor speed, Δ P1Power reference value, Δ P, for droop frequency modulation2A power reference value for virtual control; delta P1＝-KpΔf；
FIG. 5 is a diagram of a simulation verification system architecture; wherein T1 is a step-up transformer, T2 is a step-down transformer, L1 is an internal power transmission line of a wind farm, L2 is an external power transmission line of the wind farm, PL1Active power, P, for a fixed loadL2For variable load active power, QL1Reactive power, Q, for a fixed loadL2Variable load reactive power;
FIG. 6 is a frequency response characteristic diagram of the system at a wind speed of 6.3 m/s; wherein the content of the first and second substances,
FIG. 6a is a frequency response comparison graph of a system under different frequency control strategies when the wind speed is 6.3m/s and the load is increased;
FIG. 6b is a comparison graph of the active power response of the system under different frequency control strategies when the wind speed is 6.3m/s and the load is increased;
FIG. 6c is a comparison graph of the rotor speed response of the system under different frequency control strategies when the wind speed is 6.3m/s and the load is increased;
FIG. 6d is a graph comparing droop coefficients under different frequency control strategies when the wind speed is 6.3m/s and the load is increased;
FIG. 7 is a frequency response characteristic diagram of the system at a wind speed of 7.5 m/s; wherein the content of the first and second substances,
FIG. 7a is a frequency response comparison graph of a system under different frequency control strategies when the load is increased and the wind speed is 7.5 m/s;
FIG. 7b is a comparison graph of the active power response of the system under different frequency control strategies when the wind speed is 7.5m/s and the load is increased;
FIG. 7c is a comparison graph of the rotor speed response of the system under different frequency control strategies when the wind speed is 7.5m/s and the load is increased;
FIG. 7d is a graph comparing droop coefficients under different frequency control strategies when the wind speed is 7.5m/s and the load is increased;
FIG. 8 is a frequency response characteristic diagram of the system at a wind speed of 12 m/s; wherein the content of the first and second substances,
FIG. 8a is a frequency response comparison graph of a system under different frequency control strategies when the wind speed is 12m/s and the load is increased;
FIG. 8b is a comparison graph of the active power response of the system under different frequency control strategies when the wind speed is 12m/s and the load is increased;
FIG. 8c is a pitch angle response contrast chart of the system under different frequency control strategies when the wind speed is 12m/s and the load is increased;
FIG. 8d is a graph comparing droop coefficients under different frequency control strategies when the load is increased at a wind speed of 12 m/s.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
Referring to fig. 1, the embodiment is described, and the frequency modulation control method suitable for direct-drive wind farm alternating current grid connection in the embodiment includes the following steps:
step one, calculating a virtual inertia time constant H of a direct-drive wind turbine generator in a corresponding operation state; the running states of the direct-drive wind turbine generator set comprise a starting area, a maximum wind energy tracking area and a constant rotating speed area;
step two, calculating the self-adaptive droop frequency modulation coefficient K of the direct-drive wind turbine generator according to the virtual inertia time constant H in the corresponding operation statepAnd adaptive virtual inertia coefficient Kd：
Step three, according to the frequency change rate of the system
System frequency deviation delta f and self-adaptive droop frequency modulation coefficient KpAnd adaptive virtual inertia coefficient KdCalculating to obtain an additional active power reference value delta P of the direct-drive wind turbine generator participating in frequency modulation control; and adding the reference value delta P and P of active powerMPPTTo carry outStacking, P obtained after stackingrefSending the power to a direct-drive wind turbine converter control system, and receiving the P by the direct-drive wind turbine converter control systemrefControlling the output power of the direct-drive wind turbine generator set so as to realize the adjustment of the power grid frequency;
PMPPTthe maximum power tracking instruction value is the maximum power tracking instruction value of the direct-drive wind turbine generator;
Prefis a power reference value of the direct-drive wind turbine generator.
In the embodiment, firstly, virtual inertia time constants H of the direct-drive wind turbine generator set in different running states are calculated; then, calculating the self-adaptive droop frequency modulation coefficient K of the direct-drive wind turbine generator according to the virtual inertia time constant HpAnd adaptive virtual inertia coefficient Kd(ii) a Finally, obtaining an active power reference value delta P of direct-drive wind turbine generator frequency modulation control; enabling the delta P and the maximum power tracking instruction value P of the direct-drive wind turbine generatorMPPTSuperposition, active power reference value P after superpositionrefAnd sending the power to a converter control system of the direct-drive wind turbine generator, and controlling the output power of the direct-drive wind turbine generator by the control system so as to realize the adjustment of the power grid frequency.
The invention provides a frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection, which is suitable for an adaptive coefficient improvement frequency modulation control strategy of the wind power plant alternating current grid connection, wherein adaptive coefficient improvement is mainly embodied in that virtual inertia time constants H are different in values under different running states of a direct-drive wind turbine generator, and the frequency modulation control coefficient is adjusted according to the running state of the direct-drive wind turbine generator (namely, an adaptive droop frequency modulation coefficient K is adoptedpAnd adaptive virtual inertia coefficient Kd) And the purpose of calling the frequency modulation capability of the wind turbine generator to the maximum extent is further achieved, and simulation results show that the self-adaptive frequency modulation control method based on the virtual inertia time constant H can effectively improve the frequency modulation capability of the wind turbine generator, enhance the stability of the system, and simultaneously avoid the problem that the system is unstable because the control coefficient cannot be selected too large when the wind turbine generator operates at a lower wind speed.
Can be controlled according to different operation conditions of the wind turbineFrequency modulation coefficient K for making self-adaptive drooppVarying, combining deloading control and variable adaptive droop FM coefficient KpAnd controlling and coordinating the difference of the frequency modulation capability of the wind turbine generator under different wind speeds.
Further, in the preferred embodiment, in the first step:
(1) when the direct-drive wind turbine generator runs in a starting area, H is equal to 0, and at the moment, w is not more than wMPPT_1；
(2) When the direct-drive wind turbine generator runs in the maximum wind energy tracking area,
at this time, wMPPT_1≤w＜1p.u.；
(3) When the direct-drive wind turbine generator runs in a constant rotating speed region,
at this time, w is 1 p.u.;
wherein w is the rotor speed;
wMPPT_1the initial rotating speed of the maximum wind energy tracking area of the direct-drive wind turbine generator set is obtained;
j is the rotational inertia of the direct-drive wind turbine generator;
w0is the initial value of the rotor speed;
wminis the minimum value of the rotor speed;
PNthe rated power of the direct-drive wind turbine generator is set;
ρ is the air density;
r is the radius of the fan;
v is the wind speed;
t1and t2Respectively the initial moment and the end moment of the change of the rotor speed;
t is the current running time;
Cp maxthe maximum wind energy utilization coefficient;
p is the number of pole pairs;
f is the system actual frequency.
Furthermore, in the preferred embodiment, in the second step,
wherein, K1Is a reference differential coefficient;
K2is a reference scale factor.
Further, with particular reference to fig. 4, in step three,
when the method is specifically applied, firstly, aiming at a certain actual direct-drive wind power plant, the parameters of a direct-drive wind turbine generator in the wind power plant are shown in table 1, the power characteristic curve is shown in fig. 2, and the change range of the rotor rotating speed is more than or equal to w.u. and 0.55p.ur1 p.u.. ltoreq.in FIG. 2
(1) A start-up zone: curve AB, the rotational speed of the wind turbine is 0.55p.u. the minimum value of the rotational speed of the rotor;
(2) maximum wind energy tracking area: curve BC, in this region, the maximum wind tracking coefficient CPIs a fixed value;
(3) a constant rotating speed area: and the curve CD is that the rotating speed of the wind turbine generator is 1p.u. maximum of the rotating speed of the rotor. When the direct-drive wind turbine generator runs in different states, the virtual inertia time constants are different.
TABLE 1 direct-drive wind turbine main parameters
(A) The direct-drive wind turbine generator system runs in a starting area, the rotating speed is less than 0.55p.u., and the wind turbine generator system does not have the frequency modulation capability, so that the virtual inertia time constant of the direct-drive wind turbine generator system is 0, namely:
H＝0；
(B) the direct-drive wind turbine generator system operates in a maximum wind energy tracking area, the rotating speed range is 0.55p.u. -1.0 p.u., and the maximum wind energy tracking coefficient CPHeld at 0.478. During the frequency modulation, the rotor speed is reduced, CPAs the rotor speed decreases, the wind energy captured by the unit decreases. In the maximum wind energy tracking area, the pitch angle control does not act, so the virtual inertia time constant of the direct-drive wind turbine generator set can be expressed as:
in the formula, d is a differential operator.
(C) The direct-drive wind turbine generator operates in a constant rotating speed area, the rotating speed of a rotor is 1.0p.u., the rated rotating speed, and the wind turbine generator participates in the frequency modulation process CPConstantly change, the frequency modulation ability of wind turbine generator system will reduce along with output power's increase, and the virtual inertia time constant that directly drives wind turbine generator system is:
according to the three formulas, the virtual inertia time constant of the direct-drive wind turbine generator is related to the initial value of the rotor rotating speed, the changing time of the rotor rotating speed, the wind speed and the parameters of the generator. Assuming that the change time of the rotor rotation speed is 4s, according to values corresponding to the virtual inertia time constant of the direct-drive wind turbine generator in three different operation states, the relationship between the virtual inertia time constant H of the direct-drive wind turbine generator and the rotor rotation speed w and the output power P' can be calculated as shown in fig. 3. In fig. 3, when the wind turbine generator operates before the constant rotation speed region, the virtual inertia time constant increases with the increase of the rotation speed of the rotor, and the inertia of the system increases; when the wind turbine generator runs behind a constant rotating speed area, the virtual inertia time constant is reduced along with the increase of the rotating speed of the rotor, and the inertia of the system is weakened.
Secondly, calculating the self-adaptive droop frequency modulation coefficient K of the wind turbine generatorpAnd adaptive virtual inertia coefficient Kd：
In the formula, K1For reference to differential coefficient, K2For reference to the scale factor, in the examples, K1And K2Equal to 12 and 80 respectively.
Thirdly, the rotor inertia frequency modulation control method for realizing the self-adaptive coefficient obtains the self-adaptive droop frequency modulation coefficient K by calculating the virtual inertia time constant of the fan in different running statespAnd adaptive virtual inertia coefficient KdFurther, an additional active power reference value Δ P is calculated, and Δ P is compared with PMPPTPerforming superposition, and obtaining P after superpositionrefSending the data to a frequency converter control system to adjust the adaptive frequency modulation control coefficient (namely K) in real time according to different running states of the wind turbine generatorpAnd Kd) The purpose of calling the frequency modulation capability of the wind turbine generator to the maximum extent and self-adapting frequency modulation coefficient KpAnd KdThe control diagram is shown in fig. 4, and it can be seen that the additional active power reference value Δ P can be expressed as:
and (3) verification test: in order to verify the correctness of the proposed frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection, a verification system shown in fig. 5 is built in power system simulation software PSCAD/EMDTC. The wind power plant consists of 33 direct-drive wind power sets with single machine capacity of 1.5MW, the whole wind power plant is equivalent to a single wind power set, and the capacity is 50 MVA. Besides the direct-drive wind turbine generator with the parameters shown in the table 1, the system also comprises a synchronous generator and a corresponding load, and the direct-drive wind turbine generator and the synchronous generator jointly supply power to the load. The parameters of the synchronous generator are shown in table 2. The system load suddenly increases at 1s, and the system frequency decreases. In the research process, a direct-drive wind turbine generator set respectively adopts a constant coefficient droop control method and the control method (namely, a frequency modulation control method with self-adaptability), and when the constant coefficient droop control method is adopted, the droop coefficients are 12 and 30; when the method is adopted, the frequency modulation capability of the wind turbine generator is determined by the effective kinetic energy stored in the wind turbine generator, so that simulation verification is respectively carried out under three working conditions of low wind speed (6.3m/s), medium wind speed (7.5m/s) and high wind speed (12 m/s).
TABLE 2 main parameters of synchronous generator
(1) The wind speed is 6.3m/s
The frequency response characteristic of the system at a wind speed of 6.3m/s is shown in FIG. 6. As can be seen from the graphs a to d in fig. 6, the lowest point of the system frequency is raised when the droop control is used, compared to the control without additional frequency modulation. When the droop coefficient is 12, the rotating speed of the rotor is reduced, and the output active power of the wind turbine generator is increased; when the sag coefficient is 30, the rotating speed of the rotor is continuously reduced to reach the minimum value of 0.55p.u., the wind turbine generator automatically cuts off a frequency control link, so that the system frequency is rapidly dropped, and the frequency modulation capability is weakened; when the adaptive frequency modulation control method is adopted, the lowest point of the system frequency is raised, the output of the wind turbine generator is increased, the frequency modulation capability of the wind turbine generator is enhanced, and the effectiveness of the frequency modulation control method is verified.
(2) The wind speed is 7.5m/s
The frequency response characteristic of the system at a wind speed of 7.5m/s is shown in FIG. 7. As can be seen from the graphs a to d in fig. 7, when the direct-drive wind turbine generator adopts constant-coefficient droop control, along with the increase of the droop coefficient, the change range of the rotating speed of the generator rotor is increased, the output active power of the wind turbine generator is increased, and the lowest point of the system frequency is increased. When the direct-drive wind turbine generator adopts the frequency modulation control method, the droop coefficient changes along with the change of the rotating speed of the rotor, and the frequency modulation effect is best. Therefore, the frequency modulation capability of the wind turbine generator is enhanced by the adoption of the self-adaptability of the frequency modulation control method.
(3) The wind speed is 12m/s
The frequency response characteristic of the system at a wind speed of 12m/s is shown in FIG. 8. As can be seen from the graphs a to d in fig. 8, the rotor speed reaches the maximum value, and during the frequency modulation, the rotor speed is kept unchanged and the pitch angle is acted. When the frequency modulation control method is adopted by the wind turbine generator, the change range of the pitch angle is enlarged, the lowest point of the system frequency is increased, and the self-adaptability effectiveness of the frequency modulation control method is verified.
In summary, the virtual inertia time constant is calculated according to the effective kinetic energy stored in the direct-drive wind turbine generator, and the frequency modulation control method suitable for alternating current grid connection of the direct-drive wind power plant is provided based on the virtual inertia time constant. A corresponding control strategy model is set up on simulation software, and the improved frequency modulation control strategy is verified at three wind speeds, namely low wind speed, medium wind speed and high wind speed, and the result shows that the adaptive frequency modulation control method based on the virtual inertia time constant can improve the frequency modulation capability of the wind turbine generator and enhance the system stability.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.
Claims (4)
1. The frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection is characterized by comprising the following steps:
step one, calculating a virtual inertia time constant H of a direct-drive wind turbine generator in a corresponding operation state; the running states of the direct-drive wind turbine generator set comprise a starting area, a maximum wind energy tracking area and a constant rotating speed area;
step two, according to the corresponding operation stateCalculating a self-adaptive droop frequency modulation coefficient K of the direct-drive wind turbine generator set by using the virtual inertia time constant H in the statepAnd adaptive virtual inertia coefficient Kd：
Step three, according to the frequency change rate of the system
System frequency deviation delta f and self-adaptive droop frequency modulation coefficient KpAnd adaptive virtual inertia coefficient KdCalculating to obtain an additional active power reference value delta P of the direct-drive wind turbine generator participating in frequency modulation control; and adding the reference value delta P and P of active powerMPPTPerforming superposition, and obtaining P after superpositionrefSending the power to a direct-drive wind turbine converter control system, and receiving the P by the direct-drive wind turbine converter control systemrefControlling the output power of the direct-drive wind turbine generator set so as to realize the adjustment of the power grid frequency;
PMPPTthe maximum power tracking instruction value is the maximum power tracking instruction value of the direct-drive wind turbine generator;
Prefis a power reference value of the direct-drive wind turbine generator.
2. The frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection according to claim 1, characterized in that in the first step:
(1) when the direct-drive wind turbine generator runs in a starting area, H is equal to 0, and at the moment, w is not more than wMPPT_1；
(2) When the direct-drive wind turbine generator runs in the maximum wind energy tracking area,
at this time, wMPPT_1≤w＜1p.u.；
(3) When the direct-drive wind turbine generator runs in a constant rotating speed region,
at this time, w is 1 p.u.;
wherein w is the rotor speed;
wMPPT_1the initial rotating speed of the maximum wind energy tracking area of the direct-drive wind turbine generator set is obtained;
j is the rotational inertia of the direct-drive wind turbine generator;
w0is the initial value of the rotor speed;
wminis the minimum value of the rotor speed;
PNthe rated power of the direct-drive wind turbine generator is set;
ρ is the air density;
r is the radius of the fan;
v is the wind speed;
t1and t2Respectively the initial moment and the end moment of the change of the rotor speed;
t is the current running time;
Cpmaxthe maximum wind energy utilization coefficient;
p is the number of pole pairs;
f is the system actual frequency.
3. The frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection according to claim 1, characterized in that in step two,
wherein, K1Is a reference differential coefficient;
K2is a reference scale factor.
4. The frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection according to claim 1, characterized in that in step three,
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011216099.0A CN112271760A (en) | 2020-11-04 | 2020-11-04 | Frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011216099.0A CN112271760A (en) | 2020-11-04 | 2020-11-04 | Frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112271760A true CN112271760A (en) | 2021-01-26 |
Family
ID=74346067
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011216099.0A Pending CN112271760A (en) | 2020-11-04 | 2020-11-04 | Frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112271760A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113315176A (en) * | 2021-06-18 | 2021-08-27 | 哈尔滨工业大学 | Primary frequency modulation coordination control method and system of wind-fire combined system |
| CN113629728A (en) * | 2021-07-13 | 2021-11-09 | 南京理工大学 | Wind turbine generator droop control method based on execution dependency heuristic dynamic programming |
| CN113629728B (en) * | 2021-07-13 | 2024-06-07 | 南京理工大学 | Wind turbine generator set droop control method based on execution dependency heuristic dynamic programming |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106532739A (en) * | 2016-09-30 | 2017-03-22 | 哈尔滨工业大学 | Method for enabling wind power unit to participate in primary frequency modulation of power system at different bands |
| CN107910896A (en) * | 2017-11-29 | 2018-04-13 | 西南交通大学 | The method that power grid frequency modulation is participated in based on virtual inertia and award setting Wind turbines |
-
2020
- 2020-11-04 CN CN202011216099.0A patent/CN112271760A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106532739A (en) * | 2016-09-30 | 2017-03-22 | 哈尔滨工业大学 | Method for enabling wind power unit to participate in primary frequency modulation of power system at different bands |
| CN107910896A (en) * | 2017-11-29 | 2018-04-13 | 西南交通大学 | The method that power grid frequency modulation is participated in based on virtual inertia and award setting Wind turbines |
Non-Patent Citations (1)
| Title |
|---|
| 栾贻贺: "适用于频率控制的风电场建模与调频策略研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113315176A (en) * | 2021-06-18 | 2021-08-27 | 哈尔滨工业大学 | Primary frequency modulation coordination control method and system of wind-fire combined system |
| CN113315176B (en) * | 2021-06-18 | 2022-09-20 | 哈尔滨工业大学 | Primary frequency modulation coordination control method and system of wind-fire combined system |
| CN113629728A (en) * | 2021-07-13 | 2021-11-09 | 南京理工大学 | Wind turbine generator droop control method based on execution dependency heuristic dynamic programming |
| CN113629728B (en) * | 2021-07-13 | 2024-06-07 | 南京理工大学 | Wind turbine generator set droop control method based on execution dependency heuristic dynamic programming |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105134485B (en) | A kind of double-fed Wind turbine inertia frequency modulation active rotating speed Protection control system and method | |
| CN104917201A (en) | Controller and method for simulating active power frequency of double-fed induction generator (DFIG) in combination with inertia and over speed | |
| CN109936152B (en) | Grid frequency modulation control method after high-permeability wind power grid connection and wind driven generator | |
| CN113054672B (en) | Wind power frequency modulation method and system considering multi-link cooperative control | |
| CN110071526B (en) | Self-adaptive droop control method for PMSG fan participating in power grid frequency regulation | |
| CN109586319A (en) | A kind of Wind turbines participate in system frequency modulation method and system | |
| CN110890765B (en) | Dynamic rotating speed protection method and system for virtual inertia frequency modulation of doubly-fed wind turbine | |
| CN107394817B (en) | Method and system for wind power to participate in frequency modulation of power system | |
| CN107171368A (en) | The wind-power electricity generation primary frequency function implementation method controlled based on wind power | |
| CN113991705B (en) | Wind power grid-connected system frequency modulation control method with energy storage wind power plant participating in primary frequency modulation control | |
| CN112332442A (en) | Virtual inertia control strategy optimization based on double-fed wind power plant | |
| CN111786404A (en) | Wind power plant active power optimal distribution method considering optimal rotor kinetic energy | |
| CN108377004B (en) | Wind-storage coordination frequency modulation method and system based on virtual synchronous machine | |
| CN112271760A (en) | Frequency modulation control method suitable for direct-drive wind power plant alternating current grid connection | |
| CN113162071A (en) | Direct-drive permanent magnet wind turbine generator load shedding frequency modulation control method based on variable power tracking | |
| CN113162073A (en) | Wind turbine generator and energy storage coordinated frequency modulation control method and system | |
| CN108506163B (en) | Doubly-fed wind power virtual synchronous machine rotating speed recovery method, device and system | |
| CN116345486A (en) | Model predictive control-based primary frequency modulation coordination control method and device in wind field | |
| CN113904346B (en) | Wind turbine generator rotational speed recovery method considering hydroelectric frequency modulation resources | |
| CN115882524A (en) | Wind turbine generator set control parameter setting method for improving frequency response capability | |
| CN114977221A (en) | Frequency modulation control method, device and equipment for wind turbine generator and storage medium | |
| CN111342489B (en) | Grid fault voltage boosting method based on active power control of doubly-fed wind power plant | |
| CN114268136A (en) | Fan stepping inertia control improvement method considering frequency response characteristic of synchronous machine | |
| CN112769167A (en) | Wind power, thermal power and electric cooperative frequency modulation control method and system | |
| Song et al. | An electrical stall control algorithm for small-scale wind generation system using aerodynamic observer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210126 |