CN108506163B - A method, device and system for speed recovery of doubly-fed wind power virtual synchronous machine - Google Patents
A method, device and system for speed recovery of doubly-fed wind power virtual synchronous machine Download PDFInfo
- Publication number
- CN108506163B CN108506163B CN201810377112.7A CN201810377112A CN108506163B CN 108506163 B CN108506163 B CN 108506163B CN 201810377112 A CN201810377112 A CN 201810377112A CN 108506163 B CN108506163 B CN 108506163B
- Authority
- CN
- China
- Prior art keywords
- fan
- speed
- power
- wind
- value
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 51
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 32
- 238000011084 recovery Methods 0.000 title claims description 38
- 238000010586 diagram Methods 0.000 description 12
- 238000005516 engineering process Methods 0.000 description 7
- 230000006872 improvement Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 238000004088 simulation Methods 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000010408 sweeping Methods 0.000 description 3
- 101000588130 Homo sapiens Microsomal triglyceride transfer protein large subunit Proteins 0.000 description 2
- 102100031545 Microsomal triglyceride transfer protein large subunit Human genes 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000011217 control strategy Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D7/00—Controlling wind motors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2270/00—Control
- F05B2270/10—Purpose of the control system
- F05B2270/103—Purpose of the control system to affect the output of the engine
- F05B2270/1033—Power (if explicitly mentioned)
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2270/00—Control
- F05B2270/30—Control parameters, e.g. input parameters
- F05B2270/304—Spool rotational speed
-
- 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
- Y02E10/72—Wind turbines with rotation axis in wind direction
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Eletrric Generators (AREA)
- Wind Motors (AREA)
Abstract
The invention provides a method, a device and a system for recovering the rotating speed of a doubly-fed wind power virtual synchronous machine, wherein the method comprises the steps of collecting the rotating speed of a fan and judging whether the rotating speed of the fan reaches a lower limit value or not; when the rotating speed of the fan reaches a lower limit value, under the condition that the rotating speed of the fan is unchanged, the output power of the fan is adjusted to a power fixed value, and the power fixed value is calculated according to the wind speed and the wind wheel angular frequency when the rotating speed of the fan reaches the lower limit value; maintaining the output power unchanged, and adjusting the rotating speed of the fan to a tracking rotating speed, wherein the tracking rotating speed is determined according to the power fixed value; and according to the maximum power point tracking curve, recovering the rotating speed of the fan to the rotating speed of the fan at the steady-state working point corresponding to the wind speed.
Description
Technical Field
The invention relates to the field of doubly-fed fans, in particular to a doubly-fed wind power virtual synchronous machine rotating speed recovery method, device and system.
Background
With the increasing exhaustion of traditional energy and the increasing aggravation of environmental problems, new energy power generation technologies represented by photovoltaic and wind power are rapidly developed, and a doubly-fed fan occupies a considerable proportion. Because the doubly-fed wind turbine adopts an asynchronous generator, the output power of the doubly-fed wind turbine is hardly coupled with the frequency and the voltage of the power grid, so that the necessary frequency and the voltage support for the power grid are difficult to provide. With the increasing permeability of doubly-fed fans in the power grid, doubly-fed fans are urgently required to have similar frequency modulation and voltage regulation capabilities as conventional synchronous generators, and virtual synchronous machine (Virtual Synchronous Generator, VSG) technology provides a solution.
In order to ensure the economy of wind power operation, a virtual synchronous machine (fan for short) of a double-fed fan with practical engineering adopts a method without reserving spare capacity; when a frequency disturbance event occurs in the power grid, short active power support is provided for the power grid by releasing part of the kinetic energy of the rotor. The doubly-fed fans are all provided with a lower rotation speed limit protection, and when the rotation speed of the fans drops to a lower value in the wind power frequency modulation process, the fans must exit frequency modulation and gradually increase the rotation speed to an initial value. At the moment that the fan exits from frequency modulation, the output electromagnetic power of the fan falls greatly, so that the secondary fall of the system frequency is caused. When the frequency modulation strategy of the fan is improper, the problem of secondary frequency drop can be serious, and even the depth of primary frequency drop of the system is far greater.
When the doubly-fed fan virtual synchronous machine exits frequency modulation in engineering application at present, the electromagnetic power of the fan is given according to the power value corresponding to the current rotating speed on an MPPT (maximum power point tracking) curve, and the electromagnetic power can drop off instantaneously and greatly, so that the problem of serious secondary frequency drop is caused. Some documents propose methods for improving secondary drop when fans exit frequency modulation, starting from two aspects of wind power single machine and station respectively. In the single machine aspect, some scholars propose an inertia control strategy based on switching of a power tracking curve, and electromagnetic power is basically maintained at a level before frequency modulation by continuously correcting the proportional coefficient of the tracking curve in the rotating speed recovery process. The method can not provide necessary primary frequency modulation for the system, is complex in implementation method, needs online real-time correction of coefficients, and is not easy to realize engineering. Some documents propose a rotational speed delay recovery method, in which an active reference value is continuously calculated in the recovery process, so that the frequency characteristic is improved; however, this method requires accurate measurement of wind speed in real time as an input signal to the algorithm. In the aspect of a station, a part of literature proposes to configure energy storage with a certain capacity at a wind field sending end so as to compensate the falling of the output of a fan in the rotating speed recovery process; the method can effectively improve the wind power frequency modulation performance, but greatly improves the cost of the system. In addition, a learner proposes cooperative control between different fans in the wind field, the difference of the output between the fans is fully utilized, and the time for the fans to exit from frequency modulation is reasonably configured; however, this method requires a central controller at the site level and a high-speed communication network to ensure information interaction between the site and the stand-alone.
Therefore, the prior art and the method have the characteristics of high cost, difficult realization and low reliability, and cannot be popularized and applied in large scale in engineering.
Disclosure of Invention
Aiming at the problems of high cost, difficult realization and low reliability of the prior art caused by serious secondary frequency drop when a fan exits frequency modulation, the embodiment of the invention provides a doubly-fed wind power virtual synchronous machine rotating speed recovery method, a device and a system, which comprise,
collecting the rotating speed of a fan, and judging whether the rotating speed of the fan reaches a lower limit value or not;
when the rotating speed of the fan reaches a lower limit value, under the condition that the rotating speed of the fan is unchanged, the output power of the fan is adjusted to a power fixed value, and the power fixed value is calculated according to the wind speed and the wind wheel angular frequency when the rotating speed of the fan reaches the lower limit value;
maintaining the output power unchanged, and adjusting the rotating speed of the fan to a tracking rotating speed, wherein the tracking rotating speed is determined according to the power fixed value;
and according to the maximum power point tracking curve, recovering the rotating speed of the fan to the rotating speed of the fan at the steady-state working point corresponding to the wind speed.
The embodiment of the invention also provides a device for recovering the rotating speed of the doubly-fed wind power virtual synchronous machine, which comprises,
the acquisition module is used for acquiring the rotating speed of the fan and judging whether the rotating speed of the fan reaches a lower limit value or not;
the power adjusting module is used for adjusting the output power of the fan to a power fixed value under the condition that the rotating speed of the fan is unchanged when the rotating speed of the fan reaches a lower limit value; the power fixed value is calculated according to the wind speed and the wind wheel angular frequency when the rotating speed of the fan reaches the lower limit value;
the rotating speed adjusting module is used for keeping the output power unchanged and adjusting the rotating speed of the fan to a tracking rotating speed, and the tracking rotating speed is determined according to the power fixed value;
and the rotating speed recovery module is used for recovering the rotating speed of the fan to the rotating speed of the fan at the steady-state working point corresponding to the wind speed according to the maximum power point tracking curve.
The embodiment of the invention also provides a doubly-fed wind power virtual synchronous machine rotating speed recovery system, which comprises a main control unit, a converter and a doubly-fed motor;
the main control unit collects the rotating speed of the fan and judges whether the rotating speed of the fan reaches a lower limit value or not;
when the rotating speed of the fan reaches a lower limit value, the main control unit outputs a power fixed value obtained by calculation according to the wind speed and the wind wheel angular frequency when the rotating speed of the fan reaches the lower limit value to the converter control unit;
the converter control unit outputs a switching instruction to the converter according to the power fixed value, and controls the output current value of the converter;
the doubly-fed motor adjusts electromagnetic power of the doubly-fed motor to the power fixed value according to the output current value, so that the rotating speed of the fan is increased to a tracking rotating speed;
and the main control unit obtains a power reference value according to the maximum power point tracking curve and outputs the power reference value to the converter control unit so that the rotating speed of the fan is increased to the rotating speed of the fan at a steady-state working point corresponding to the wind speed.
The method greatly improves the serious frequency secondary drop problem caused by the traditional rotating speed recovery method by changing the output power of the fan, and provides powerful support for further popularization and application of the wind power virtual synchronous machine technology under the condition of not increasing the equipment cost, thereby achieving the purposes of low cost and easy engineering realization and solving the frequency secondary drop problem.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the description below are only some embodiments of the invention and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1A and 1B are simulation diagrams of an MPPT rotational speed recovery method in the prior art;
FIG. 2 is a flowchart of a method for recovering the rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the invention;
FIG. 3 is a schematic diagram of a method for recovering the rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the invention;
FIG. 4 is a schematic structural diagram of a rotational speed recovery device of a doubly-fed wind power virtual synchronous machine according to an embodiment of the invention;
FIG. 5 is a schematic structural diagram of a doubly-fed wind power virtual synchronous machine rotational speed recovery system according to an embodiment of the present invention;
fig. 6A and fig. 6B are simulation diagrams of a method for recovering a rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the invention.
Detailed Description
The embodiment of the invention provides a doubly-fed wind power virtual synchronous machine rotating speed recovery method, device and system.
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Fig. 1A and fig. 1B are simulation diagrams of an MPPT rotational speed recovery method in the prior art, and fig. 1A shows frequency characteristics of a system when 4% load disturbance occurs in a power grid with a loading ratio of 20% of a doubly-fed fan. Fig. 1B shows two phases of frequency modulation for wind power (fan electromagnetic power), namely an inertial support phase and a rotational speed recovery phase. In the inertial support stage, electromagnetic power increases, the rotating speed of the fan is continuously reduced, and the input mechanical power of the fan is reduced. When the rotating speed of the fan reaches the set lower limit, if the existing MPPT curve recovery mode is adopted, the electromagnetic power instantaneously drops to a power value corresponding to the current rotating speed on the MPPT tracking curve, and then the rotating speed and the electromagnetic power are gradually recovered. As can be seen from fig. 1A, when wind power is subjected to frequency modulation by adopting the MPPT curve recovery mode, the depth of primary frequency drop can be reduced to a certain extent, but serious secondary drop is caused.
Fig. 2 is a flowchart of a method for recovering the rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the present invention, which includes,
s1, collecting the rotating speed of a fan, and judging whether the rotating speed of the fan reaches a lower limit value or not;
s2, when the rotating speed of the fan reaches a lower limit value, under the condition that the rotating speed of the fan is unchanged, adjusting the output power of the fan to a power fixed value, wherein the power fixed value is calculated according to the wind speed and the wind wheel angular frequency when the rotating speed of the fan reaches the lower limit value;
s3, keeping the output power unchanged, and adjusting the rotating speed of the fan to a tracking rotating speed, wherein the tracking rotating speed is determined according to the power fixed value;
s4, recovering the rotating speed of the fan to the rotating speed of the fan at the steady-state working point corresponding to the wind speed according to the maximum power point tracking curve.
In this embodiment, by collecting the fan rotation speed, it is determined whether the current fan rotation speed reaches the lower limit value. When the rotating speed of the fan reaches the lower limit, the output power of the fan is adjusted to a fixed power value, and the process time for adjusting the output power is extremely short, so that the rotating speed of the fan is unchanged when the output power is adjusted. The fixed power value is obtained through the current wind speed, namely the wind speed when the rotating speed of the fan reaches the lower limit value, and the current wind wheel angular frequency.
After the output power of the fan is adjusted to be a fixed power value, the output power is kept unchanged, the rotating speed of the fan is increased to a tracking rotating speed, and the tracking rotating speed is determined by the fixed power value. And after the rotating speed of the fan is regulated to the tracking rotating speed, the rotating speed of the fan is restored to the rotating speed under the steady-state working point corresponding to the current wind speed according to an MPPT (maximum power point tracking) curve.
As one embodiment of the present invention, the power fixed value is calculated according to a wind speed and a wind wheel angular frequency when the rotation speed of the fan reaches a lower limit value, and λ is calculated according to the following formula:
wherein ω is the wind wheel angular frequency, v is the wind speed, and R is the wind wheel radius; calculating the mechanical power P according to the following formula m ：
Wherein C is P (lambda, beta) is a wind energy utilization coefficient, is a function of a tip speed ratio lambda and a pitch angle beta, rho is air density, and s is a wind sweeping area of the wind wheel; the power fixed value P is calculated according to the following formula 2 ，
P 2 ＝P m -ΔP 2 (3)
Wherein DeltaP 2 For a fixed value delta of power, ΔP 2 ＞0。
In this embodiment, the tip speed ratio can be calculated according to the formula (1) through the collected wind speed and the fan angular frequency, and then the mechanical power is calculated according to the formula (2), so that the mechanical power needs to be greater than the fixed power value of the fan in order to increase the rotation speed of the fan. Accordingly, the corresponding increment is reduced based on the mechanical power according to the formula (3), whereby a fixed value of the power of the blower can be obtained.
As one embodiment of the present invention, the tracking rotational speed is determined according to the power fixed value, and includes, according to the maximum power point tracking curve, the rotational speed corresponding to the power fixed value is the tracking rotational speed.
In this embodiment, according to the MPPT curve, the power fixed value has a corresponding rotation speed value on the curve, and the rotation speed value is the tracking rotation speed.
As an embodiment of the present invention, before the collecting the rotation speed of the fan, the method further includes controlling the fan to start frequency modulation so as to increase the output power of the fan.
Before the rotating speed of the fan is recovered, the fan enters a frequency modulation stage and is used for supporting a power grid. During the frequency modulation phase of the fan, the output power of the fan increases, thereby causing the fan speed to decrease.
In this embodiment, the method further includes controlling the fan to exit from frequency modulation when the rotational speed of the fan reaches a lower limit value.
The fan continuously drops in the frequency modulation stage, and the fan exits from frequency modulation when the rotation speed of the fan drops to the lower limit value of the rotation speed.
Fig. 3 is a schematic diagram of a method for recovering the rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the present invention, where two curves in the diagram are a fan MPPT tracking curve (solid line) and a mechanical power curve of the fan at a certain wind speed v, respectively. Initially, the fan is operated at point a. When the power grid frequency drops, the fan starts to modulate frequency, and the electromagnetic power rises to the point B. The rotating speed of the fan gradually decreases in the supporting process, and when the rotating speed reaches the lower limit of the rotating speed (point C), the virtual synchronous machine of the fan exits from frequency modulation. If the traditional MPPT curve recovery mode is adopted, the fan output electromagnetic power instantaneously drops to the E point, and then gradually recovers along the MPPT tracking curve. Therefore, when the traditional MPPT curve recovery mode is adopted, the output power of the fan moves along the track A-B-C-E-A, and the electromagnetic power generation amplitude value at the moment of exiting frequency modulation is delta Pe 1 +ΔPe 2 Causing severe frequency secondary drops. In order to reduce the electromagnetic power drop depth, the electromagnetic power drops to the point F higher than the point E when the fan exits from frequency modulation, and the fixed value is maintained until the fan intersects with the MPPT tracking curve at the point G. Ext> subsequentlyext>,ext> theext> electromagneticext> powerext> isext> graduallyext> restoredext> alongext> Gext> -ext> aext>.ext> Ext> itext> canext> beext> seenext> thatext> theext> fanext> outputext> powerext> movesext> alongext> theext> Aext> -ext> Bext> -ext> Cext> -ext> Fext> -ext> Gext> -ext> Aext> trackext> whenext> theext> rotationalext> speedext> comprehensiveext> recoveryext> modeext> isext> adoptedext>,ext> andext> theext> electromagneticext> powerext> dropext> amplitudeext> isext> deltaext> Peext> whenext> theext> frequencyext> modulationext> isext> exitedext> 1 +ΔPe 3 The problem of frequency secondary drop can be greatly improved. It should be noted that in order to ensure speed recovery, point F must be lower than the mechanical power D of the fan at the time of de-modulating.
The method of the invention adopts a mode of changing the output power of the fan, thereby greatly improving the serious frequency secondary drop problem caused by the traditional rotating speed recovery method, and providing powerful support for further popularization and application of the wind power virtual synchronous machine technology under the condition of not increasing the equipment cost, thereby achieving the purposes of low cost and easy engineering realization and solving the frequency secondary drop problem.
Fig. 4 is a schematic structural diagram of a speed recovery device for a doubly-fed wind power virtual synchronous machine according to an embodiment of the present invention, where the device includes an acquisition module 10, configured to acquire a speed of a fan, and determine whether the speed of the fan reaches a lower limit value;
the power adjustment module 20 is configured to adjust the output power of the fan to a fixed power value under the condition that the rotation speed of the fan is unchanged when the rotation speed of the fan reaches a lower limit value; the power fixed value is calculated according to the wind speed and the wind wheel angular frequency when the rotating speed of the fan reaches the lower limit value;
the rotation speed adjusting module 30 is configured to keep the output power unchanged, and adjust the rotation speed of the fan to a tracking rotation speed, where the tracking rotation speed is determined according to the fixed power value;
and the rotating speed recovery module 40 is used for recovering the rotating speed of the fan to the rotating speed of the fan at the steady-state working point corresponding to the wind speed according to the maximum power point tracking curve.
In this embodiment, the collecting module 10 collects the fan rotation speed, and determines whether the current fan rotation speed reaches the lower limit value. When the rotation speed of the fan reaches the lower limit, the power adjustment module 20 adjusts the output power of the fan to a fixed power value, and the process time for adjusting the output power is extremely short, so that the rotation speed of the fan is unchanged when the output power is adjusted. The fixed power value is obtained through the current wind speed, namely the wind speed when the rotating speed of the fan reaches the lower limit value, and the current wind wheel angular frequency.
After the fan output power is adjusted to a fixed power value, the rotation speed adjusting module 30 keeps the output power unchanged, adjusts the fan rotation speed to rise to a tracking rotation speed, and the tracking rotation speed is determined by the fixed power value. After the fan speed is adjusted to the tracking speed, the speed recovery module 40 recovers the fan speed to the speed at the steady-state operating point corresponding to the current wind speed according to the MPPT (maximum power point tracking) curve.
As one embodiment of the present invention, the power fixed value is calculated according to a wind speed and a wind wheel angular frequency when the rotation speed of the fan reaches a lower limit value, and λ is calculated according to the following formula:
wherein ω is the wind wheel angular frequency, v is the wind speed, and R is the wind wheel radius; calculating the mechanical power P according to the following formula m ：
Wherein C is P (lambda, beta) is a wind energy utilization coefficient, is a function of a tip speed ratio lambda and a pitch angle beta, rho is air density, and s is a wind sweeping area of the wind wheel; the power fixed value P is calculated according to the following formula 2 ，
P 2 ＝P m -ΔP 2 (3)
Wherein DeltaP 2 For a fixed value delta of power, ΔP 2 ＞0。
In this embodiment, the tip speed ratio can be calculated according to the formula (1) through the collected wind speed and the fan angular frequency, and then the mechanical power is calculated according to the formula (2), so that the mechanical power needs to be greater than the fixed power value of the fan in order to increase the rotation speed of the fan. Accordingly, the corresponding increment is reduced based on the mechanical power according to the formula (3), whereby a fixed value of the power of the blower can be obtained.
As one embodiment of the present invention, the tracking rotational speed is determined according to the power fixed value, and includes, according to the maximum power point tracking curve, the rotational speed corresponding to the power fixed value is the tracking rotational speed.
In this embodiment, according to the MPPT curve, the power fixed value has a corresponding rotation speed value on the curve, and the rotation speed value is the tracking rotation speed.
As an embodiment of the present invention, before the collecting module collects the rotation speed of the fan, the apparatus further includes a frequency modulation starting module 50 for controlling the fan to start frequency modulation so as to increase the output power of the fan.
Before the fan rotation speed is recovered, the frequency modulation starting module 50 controls the fan to enter a frequency modulation stage for supporting a power grid. During the frequency modulation phase of the fan, the output power of the fan increases, thereby causing the fan speed to decrease.
In this embodiment, the apparatus further includes a frequency modulation exit module 60, configured to control the fan to exit frequency modulation when the rotational speed of the fan reaches a lower limit value.
Wherein, the fan is in the frequency modulation stage, and the rotational speed is continuously reduced, and when the rotational speed of the fan is reduced to the lower limit value of the rotational speed, the frequency modulation exit module 60 controls the fan to exit the frequency modulation.
The device of the invention adopts a mode of changing the output power of the fan, thereby greatly improving the serious frequency secondary drop problem caused by the traditional rotating speed recovery method, and providing powerful support for further popularization and application of the wind power virtual synchronous machine technology under the condition of not increasing the equipment cost, thereby achieving the purposes of low cost and easy engineering realization and solving the frequency secondary drop problem.
Fig. 5 is a schematic structural diagram of a system for recovering rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the present invention, where the system includes a main control unit 100, a converter control unit 200, a converter 300, and a doubly-fed motor 400;
the main control unit 100 collects the rotation speed of the fan and judges whether the rotation speed of the fan reaches a lower limit value;
when the rotation speed of the fan reaches a lower limit value, the main control unit 100 outputs a power fixed value calculated according to the wind speed and the wind wheel angular frequency when the rotation speed of the fan reaches the lower limit value to the converter control unit 200;
the converter control unit 200 outputs a switching instruction to the converter 300 according to the power fixed value, and controls an output current value of the converter 300;
the doubly-fed motor 400 adjusts the electromagnetic power of the doubly-fed motor 400 to the power fixed value according to the output current value, so that the rotating speed of the fan is increased to a tracking rotating speed;
the main control unit 100 obtains a power reference value according to the maximum power point tracking curve, and outputs the power reference value to the converter control unit 200, so that the fan rotation speed is increased to the fan rotation speed at the steady-state working point corresponding to the wind speed.
In this embodiment, the main control unit 100 determines whether the current fan rotation speed reaches the lower limit value by collecting the fan rotation speed. When the rotating speed of the fan reaches the lower limit, the output power of the fan is adjusted to a fixed power value, and the process time for adjusting the output power is extremely short, so that the rotating speed of the fan is unchanged when the output power is adjusted. The fixed power value is obtained by the current wind speed, that is, the wind speed when the fan rotation speed reaches the lower limit value, and the current wind wheel angular frequency, and is output to the converter control unit 200.
The inverter control unit 200 outputs a switching command to the inverter 300 according to the fixed power value, thereby controlling the output current of the inverter 300. One end of the current transformer 300 is connected to a power grid, and the other end of the current transformer 300 is connected to the doubly-fed motor 400 and outputs an output current to the doubly-fed motor 400. The doubly-fed motor 400 adjusts the electromagnetic power output by the doubly-fed motor according to the output current to enable the electromagnetic power value to be equal to the fixed power value, so that the rotating speed of the fan is adjusted to the tracking rotating speed.
The main control unit 100 obtains a power reference value according to the maximum power point tracking curve, and outputs the power reference value to the converter control unit 200. The converter control unit 200 re-outputs another switching command to the converter 300 according to the power reference value, controls the output current of the converter 300, and outputs the output current to the doubly-fed motor 400. The doubly-fed motor 400 adjusts the electromagnetic power output by the doubly-fed motor according to the output current to enable the electromagnetic power value to be equal to the power reference value, so that the fan rotating speed is increased to the fan rotating speed at the steady-state working point corresponding to the current wind speed.
As one embodiment of the present invention, the power fixed value calculated according to the wind speed and the angular frequency of the wind wheel when the rotation speed of the fan reaches the lower limit value includes that λ is calculated according to the following formula:
wherein ω is the wind wheel angular frequency, v is the wind speed, and R is the wind wheel radius; calculating the mechanical power P according to the following formula m ：
Wherein C is P (lambda, beta) is a wind energy utilization coefficient, is a function of a tip speed ratio lambda and a pitch angle beta, rho is air density, and s is a wind sweeping area of the wind wheel; the power fixed value P is calculated according to the following formula 2 ，
P 2 ＝P m -ΔP 2 (3)
Wherein DeltaP 2 For a fixed value delta of power, ΔP 2 ＞0。
In this embodiment, the tip speed ratio can be calculated according to the formula (1) through the collected wind speed and the fan angular frequency, and then the mechanical power is calculated according to the formula (2), so that the mechanical power needs to be greater than the fixed power value of the fan in order to increase the rotation speed of the fan. Accordingly, the corresponding increment is reduced based on the mechanical power according to the formula (3), whereby a fixed value of the power of the blower can be obtained.
As an embodiment of the present invention, the tracking rotation speed is a rotation speed corresponding to the power fixed value according to the maximum power point tracking curve.
In this embodiment, according to the MPPT curve, the power fixed value has a corresponding rotation speed value on the curve, and the rotation speed value is the tracking rotation speed.
As an embodiment of the present invention, the system further comprises a gear box 500 connected between the wind wheel 600 and the doubly-fed motor 400 for matching the rotational speeds of the wind wheel 600 and the doubly-fed motor 400.
In this embodiment, the gear box 500 is connected between the wind wheel 600 (fan impeller) and the doubly-fed motor 400 to match the low rotation speed of the wind wheel 600 with the high rotation speed of the doubly-fed motor 400.
As an embodiment of the present invention, the converter control unit 200 is further configured to collect the grid-tie point frequency, and send the grid-tie point frequency to the main control unit 100.
In this embodiment, the converter control unit 200 outputs the collected grid-connected point frequency to the main control unit 100 for calculating a frequency modulation reference value, where the frequency reference value is used in a frequency modulation stage of the fan.
The system of the invention adopts a mode of changing the output power of the fan, thereby greatly improving the serious frequency secondary drop problem caused by the traditional rotating speed recovery method, and providing powerful support for further popularization and application of the wind power virtual synchronous machine technology under the condition of not increasing the equipment cost, thereby achieving the purposes of low cost and easy engineering realization and solving the frequency secondary drop problem.
Fig. 6A and fig. 6B show simulation diagrams of a method for recovering the rotational speed of a doubly-fed wind power virtual synchronous machine according to an embodiment of the invention, wherein the simulation conditions in the diagrams are that the fan duty ratio is 20%, and load disturbance of 4% of system capacity is applied. Fig. 6A is a frequency waveform at the time of recovering the rotational speed, which includes the MPPT recovery method in the prior art and the recovery method in the present invention, and the frequency waveform is the frequency waveform under the condition of different power fixed values. As can be seen from the graph, the power fixed values are selected to be 0.25pu, 0.30pu and 0.35pu, and obviously, the higher the power fixed value is, the better the improvement effect on the secondary drop is. It should be noted that the fixed power value must not be selected higher than the mechanical power input by the current fan, otherwise the fan rotation speed will continuously decrease. On the premise of meeting the requirements, the power fixed value should be selected as large as possible, so that the problem of secondary frequency drop is improved to the greatest extent. As is also apparent from fig. 6A, the fan speed recovery method of the present invention is much better in secondary drop improvement than the MTTP recovery method of the prior art.
Fig. 6B is an electromagnetic power waveform at the time of recovering the rotational speed, which includes the MPPT recovering method in the prior art and the recovering method in the present invention, and power waveforms under different power fixed values. Consistent with the law in fig. 6A, the higher the power fixed value, the better the improvement effect on the power sag. Therefore, as is apparent from fig. 6A and 6B, the fan speed recovery method of the present invention has much better effect on secondary drop and power drop improvement than the MTTP recovery method of the prior art.
The invention adopts a mode of changing the output power of the fan, thereby greatly improving the serious frequency secondary drop problem caused by the traditional rotating speed recovery method, and providing powerful support for further popularization and application of the wind power virtual synchronous machine technology under the condition of not increasing the equipment cost, thereby achieving the purposes of low cost and easy engineering realization and solving the frequency secondary drop problem.
Those of ordinary skill in the art will appreciate that all or a portion of the steps in implementing the methods of the above embodiments may be implemented by a program that instructs associated hardware, and the program may be stored on a computer readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc.
The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810377112.7A CN108506163B (en) | 2018-04-25 | 2018-04-25 | A method, device and system for speed recovery of doubly-fed wind power virtual synchronous machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810377112.7A CN108506163B (en) | 2018-04-25 | 2018-04-25 | A method, device and system for speed recovery of doubly-fed wind power virtual synchronous machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108506163A CN108506163A (en) | 2018-09-07 |
| CN108506163B true CN108506163B (en) | 2024-01-30 |
Family
ID=63383124
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810377112.7A Active CN108506163B (en) | 2018-04-25 | 2018-04-25 | A method, device and system for speed recovery of doubly-fed wind power virtual synchronous machine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108506163B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109193768B (en) * | 2018-09-19 | 2019-12-13 | 清华大学 | Virtual synchronous machine control method and device of wind power generation system |
| CN111313464B (en) * | 2020-02-27 | 2023-06-16 | 云南电网有限责任公司电力科学研究院 | Comprehensive frequency modulation control method for wind farm |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102102631A (en) * | 2011-03-22 | 2011-06-22 | 国电联合动力技术有限公司 | Running control method for wind generating set with gear box speed regulation front end |
| CN103296951A (en) * | 2013-05-29 | 2013-09-11 | 哈尔滨工业大学 | Control method of birotor-structure variable-speed constant-frequency wind power generation system |
| CN103437955A (en) * | 2013-08-13 | 2013-12-11 | 华北电力大学（保定） | Maximum power tracking device for mini permanent magnetic direct drive wind power generation system and control method |
| EP2738904A2 (en) * | 2012-11-30 | 2014-06-04 | General Electric Company | Method and systems for operating a wind turbine when recovering from a mains power failure |
| WO2014089955A1 (en) * | 2012-12-12 | 2014-06-19 | 天津市电力公司 | Maximum output tracking control method of wind generation unit based on extremum research |
| CN104454346A (en) * | 2014-11-09 | 2015-03-25 | 华北电力大学（保定） | Maximum power tracking control method for small permanent-magnet direct-drive wind power generation system |
| CN105226723A (en) * | 2015-11-19 | 2016-01-06 | 国家电网公司 | A kind of double-fed fan motor unit is based on the virtual inertia control method of wind power tracking Automatic adjusument |
| CN105281623A (en) * | 2015-11-20 | 2016-01-27 | 上海电力学院 | Method for controlling virtual inertia of doubly fed induction wind turbine |
| CN105332853A (en) * | 2015-11-30 | 2016-02-17 | 东南大学 | Control method for coordinating rotating speed and power of wind driven generator at wind speed higher than rated wind speed |
| CN105673322A (en) * | 2016-01-28 | 2016-06-15 | 南京理工大学 | Variable parameter nonlinear feedback control method achieving wind turbine MPPT control |
| CN106050558A (en) * | 2016-06-02 | 2016-10-26 | 三重型能源装备有限公司 | Wind power generation maximum output power tracking method and system based on rotation speed control |
| CN107529587A (en) * | 2017-07-17 | 2018-01-02 | 哈尔滨理工大学 | Wind light mutual complementing maximum power tracing method based on genetic algorithm |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7679215B2 (en) * | 2004-12-17 | 2010-03-16 | General Electric Company | Wind farm power ramp rate control system and method |
| US10054108B2 (en) * | 2014-10-10 | 2018-08-21 | General Electric Company | Wind turbine system and method for controlling a wind turbine system by power monitoring |
| US20160160839A1 (en) * | 2014-12-09 | 2016-06-09 | State Grid Corporation Of China | Method for controlling inertia response of variable-speed wind turbine generator |
-
2018
- 2018-04-25 CN CN201810377112.7A patent/CN108506163B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102102631A (en) * | 2011-03-22 | 2011-06-22 | 国电联合动力技术有限公司 | Running control method for wind generating set with gear box speed regulation front end |
| EP2738904A2 (en) * | 2012-11-30 | 2014-06-04 | General Electric Company | Method and systems for operating a wind turbine when recovering from a mains power failure |
| WO2014089955A1 (en) * | 2012-12-12 | 2014-06-19 | 天津市电力公司 | Maximum output tracking control method of wind generation unit based on extremum research |
| CN103296951A (en) * | 2013-05-29 | 2013-09-11 | 哈尔滨工业大学 | Control method of birotor-structure variable-speed constant-frequency wind power generation system |
| CN103437955A (en) * | 2013-08-13 | 2013-12-11 | 华北电力大学（保定） | Maximum power tracking device for mini permanent magnetic direct drive wind power generation system and control method |
| CN104454346A (en) * | 2014-11-09 | 2015-03-25 | 华北电力大学（保定） | Maximum power tracking control method for small permanent-magnet direct-drive wind power generation system |
| CN105226723A (en) * | 2015-11-19 | 2016-01-06 | 国家电网公司 | A kind of double-fed fan motor unit is based on the virtual inertia control method of wind power tracking Automatic adjusument |
| CN105281623A (en) * | 2015-11-20 | 2016-01-27 | 上海电力学院 | Method for controlling virtual inertia of doubly fed induction wind turbine |
| CN105332853A (en) * | 2015-11-30 | 2016-02-17 | 东南大学 | Control method for coordinating rotating speed and power of wind driven generator at wind speed higher than rated wind speed |
| CN105673322A (en) * | 2016-01-28 | 2016-06-15 | 南京理工大学 | Variable parameter nonlinear feedback control method achieving wind turbine MPPT control |
| CN106050558A (en) * | 2016-06-02 | 2016-10-26 | 三重型能源装备有限公司 | Wind power generation maximum output power tracking method and system based on rotation speed control |
| CN107529587A (en) * | 2017-07-17 | 2018-01-02 | 哈尔滨理工大学 | Wind light mutual complementing maximum power tracing method based on genetic algorithm |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108506163A (en) | 2018-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111277001B (en) | Fan grid-connected control method based on virtual synchronous generator parameter adaptive control | |
| EP3987170B1 (en) | Fast frequency support from wind turbine systems | |
| US9341163B2 (en) | Wind-turbine-generator control apparatus, wind turbine generator system, and wind-turbine-generator control method | |
| CN107453410B (en) | Load disturbance double-fed fan participated wind-diesel micro-grid frequency modulation control method | |
| CN105134485A (en) | Inertial frequency-modulation drive rotating speed protection control system and method for doubly-fed wind turbine | |
| WO2021209579A1 (en) | Method of operating a wind turbine and control system | |
| CN113346562B (en) | Control method for low-voltage ride through of permanent magnet direct-drive wind turbine generator | |
| EP2660464B1 (en) | Control device for wind power generation device, wind power generation system, and control method for wind power generation device | |
| CN112994074B (en) | Low and high voltage continuous ride-through control method and system for permanent magnet direct drive wind turbines | |
| Hu et al. | Impact of wind shear and tower shadow effects on power system with large scale wind power penetration | |
| CN110867894A (en) | A dynamic frequency division wind power generation system with autonomous inertia response | |
| CN108506163B (en) | A method, device and system for speed recovery of doubly-fed wind power virtual synchronous machine | |
| CN110829898A (en) | Starting control method for grid connection of new energy synchronous motor | |
| Singh et al. | Performance of wind energy conversion system using a doubly fed induction generator for maximum power point tracking | |
| CN113904346B (en) | Wind turbine generator rotational speed recovery method considering hydroelectric frequency modulation resources | |
| CN115882524A (en) | A Wind Turbine Control Parameter Tuning Method for Improving Frequency Response Capability | |
| CN112968464A (en) | High and low voltage continuous ride-through control method and system for permanent magnet direct drive wind turbine | |
| CN103545842A (en) | Control structure for coordinating different wind turbines in a wind farm to achieve low voltage ride-through capability of wind farms | |
| Imai et al. | A novel virtual synchronous generator control of PMSG-based wind generation system to enhance transient stability of power system | |
| Barambones et al. | Wind turbine output power maximization based on sliding mode control strategy | |
| CN116667378A (en) | Wind turbine generator variable inertia control method considering fan rotation speed and power grid frequency change | |
| Arunkumar et al. | Low voltage ride through capability improvement in a grid connected wind energy conversion system using STATCOM | |
| CN111342489B (en) | Grid fault voltage boosting method based on active power control of doubly-fed wind power plant | |
| Roga et al. | Energy converters for wind turbines: implementation of control methods | |
| Abdelkader et al. | Vector controlled brushless doubly fed twin stator cascaded induction generator for variable speed wind generation connected to weak grids |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |