CA3023914A1 - Method for operating a wind farm, and wind farm - Google Patents
Method for operating a wind farm, and wind farm Download PDFInfo
- Publication number
- CA3023914A1 CA3023914A1 CA3023914A CA3023914A CA3023914A1 CA 3023914 A1 CA3023914 A1 CA 3023914A1 CA 3023914 A CA3023914 A CA 3023914A CA 3023914 A CA3023914 A CA 3023914A CA 3023914 A1 CA3023914 A1 CA 3023914A1
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- Prior art keywords
- wind
- farm
- icing
- wind turbine
- pilot
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- 238000000034 method Methods 0.000 title claims abstract description 25
- 230000004913 activation Effects 0.000 claims abstract description 40
- 230000004075 alteration Effects 0.000 claims abstract description 27
- 238000011156 evaluation Methods 0.000 claims abstract description 25
- 230000006872 improvement Effects 0.000 claims abstract description 9
- 238000004590 computer program Methods 0.000 claims abstract description 6
- 238000010248 power generation Methods 0.000 claims description 3
- 238000005265 energy consumption Methods 0.000 claims description 2
- 230000008859 change Effects 0.000 description 5
- 230000005611 electricity Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000007787 solid Substances 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
- F03D80/00—Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
- F03D80/40—Ice detection; De-icing means
-
- 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
- F03D7/02—Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor
- F03D7/04—Automatic control; Regulation
- F03D7/042—Automatic control; Regulation by means of an electrical or electronic controller
- F03D7/048—Automatic control; Regulation by means of an electrical or electronic controller controlling wind farms
-
- 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
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- 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)
- Wind Motors (AREA)
Abstract
The invention relates to a method for operating a wind farm (1), and to a wind farm (1) designed to execute this method, and to a corresponding computer program product. In the case of the method for operating a wind farm (1) comprising at least two wind turbines (2), which each have a de-icing system (23) for the rotor blades (22) of the respective wind turbine (2), the alteration of the activation state of the de-icing systems (23) of the wind turbines (2) of the wind farm (1) is controlled in a coordinated manner, according to the steps: a) evaluating the operating state of at least one pilot wind turbine (2') selected from the wind turbines (2) of the wind farm (1); b) altering the activation state of the de-icing system (23) in the case of the at least one pilot wind turbine (2'); c) evaluating over again the operating state of the at least one pilot wind turbine (2'); and d) if an improvement is ascertained in the evaluation of the operating state in the case of at least one pilot wind turbine (2'), altering the activation state of the de-icing system (23) of at least one further wind turbine (2) of the wind farm (1).
Description
METHOD FOR OPERATING A WIND FARM, AND WIND FARM
The invention relates to a method for operating a wind farm, and to a wind farm designed to execute this method, and to a corresponding computer program product.
Wind farms, comprising a plurality of wind turbines that are technically connected, at least partly, for example, by means of a transmission line grid that is internal to the wind farm, are known from the prior art.
It is furthermore known that, in certain weather conditions, there is the risk that outer parts of wind turbines, in particular their rotor blades, can ice over. If the rotor blades become iced over, their very precisely calculated and manufactured shape is altered, such that the aerodynamics on the rotor blades is impaired. This regularly not only results in yield losses but, in the case of uneven ice accretion on the individual rotor blades, can also result in unbalance of the rotor and in vibrations that can damage the wind turbine.
Finally, there is also the risk that, upon further operation, ice formed on the rotor blades is spun out as a result of the considerable centrifugal forces, and can cause injury to persons or damage to property, even at some distance from the wind turbine.
To enable wind turbines to be operated even in weather conditions in which there is a risk of ice accretion, in order thus to avoid a complete yield failure, it is known to de-ice the rotor blades by heating. The heating may be effected by resistance heating elements distributed over the rotor blades, or by blowing hot air into the largely hollow rotor blades. Irrespective of the type of de-icing, this requires a considerable expenditure of energy.
In the prior art, the de-icing is switched on and off by the control system of wind turbine that may be affected, according to a predefined feedback control scheme, but without the possibility of ensuring beforehand that de-icing is actually possible, or that the yield of the wind turbine will increase by an amount that justifies the energy demand required for the de-icing.
In particular, in the case of the de-icing of a plurality of wind turbines of a wind farm, the de-icing of all wind turbines is very cost-intensive, owing to the amount of energy required for this.
This applies, in particular, if the energy required for this cannot be raised by the wind farm itself, but has to be drawn from the electricity supply grid. The problems mentioned above in relation to individual wind turbines can thus multiply further in the case of a wind farm.
The invention is based on the object of creating a method for operating a wind farm, and a wind farm designed to execute this method, in which the stated problems from the prior art no longer occur, or occur only to a reduced extent.
This object is achieved by a method according to the main claim, and by a wind farm according to claim 8, and by a computer program product according to claim 10.
Advantageous io developments are provided by the dependent claims.
Accordingly, the invention relates to a method for operating a wind farm comprising at least two wind turbines, which each have a de-icing system for the rotor blades of the respective wind turbine, the alteration of the activation state of the de-icing systems of the wind turbines of the wind farm being controlled in a coordinated manner, and comprising the steps:
e) evaluating the operating state of at least one pilot wind turbine selected from the wind turbines of the wind farm;
f) altering the activation state of the de-icing system in the case of the at least one pilot wind turbine;
g) evaluating over again the operating state of the at least one pilot wind turbine; and h) if an improvement is ascertained in the evaluation of the operating state in the case of at least one pilot wind turbine, altering the activation state of the de-icing system of at least one further wind turbine of the wind farm.
Furthermore, the invention relates to a wind farm comprising a plurality of wind turbines connected to a grid that is internal to the wind farm, each having a rotor and a de-icing system for the rotor blades of the rotor, the wind farm being designed to execute the method according to the invention.
¨ 2 -The invention additionally relates to a computer program product, comprising program parts that are designed, when loaded in a computer, preferably the system controller of a wind turbine or a central wind-farm controller, to execute the method according to the invention.
The invention is based on the recognition that, in comparison with the prior art, clear advantages are obtained from a coordinated control of the de-icing systems of the wind turbines of a wind farm. It is sufficient in this case if this control coordinates only the activation state of the individual de-icing systems - i.e. whether, basically, they are switched on or switched off - while the further feedback control and monitoring of the de-icing system, for io example in respect of the temperature, can be effected by the respective system controller of the individual wind turbines, in a manner comparable to the prior art.
By appropriate control it is possible to alter the activation state of the de-icing system - whether then by switching on or switching off - initially in the case of one or more -but not all - wind .. turbines of the wind farm, as so-called pilot wind turbines, and to check on these pilot wind turbines whether the performed alteration of the activation state results in an improvement in their operation. In the case of extensive ice accretion that prohibits the operation of a wind turbine, it may be the case that it is only possible for a pilot wind turbine to be put into operation at all by the activation of the de-icing system. It is only when the operating state improves by a sufficient amount in the case of the pilot wind turbine or turbines that the alteration of the activation state of the de-icing system effected there is also effected in the case of the other wind turbines of the wind farm that do not constitute pilot wind turbines.
To enable ascertainment of a possible improvement in the operating state of a pilot wind turbine, by alteration of the activation state of the de-icing system, the operating state of the pilot wind turbine is evaluated before the said alteration. For this purpose, various operating characteristic numbers such as, for example, the current generated power, the efficiency of the wind turbine (i.e. the ratio of wind power to generated power) or the internal consumption of the wind turbine (i.e. the internal consumption of the components required for the operation of the wind turbine), may be taken into account. Factors relating to the operational safety of the wind turbine that result, for example, from rotor unbalances and/or the risk of ice shedding, may also be taken into account.
¨ 3 -All factors to be taken into account in the evaluation of the operating state of the wind turbine may be weighted and combined in an index number. If the wind turbine is stopped at the time of evaluation of the operating state, for example because of a high risk of ice shedding, this results in an unfavourable index number, both because of absence of power infeed and owing to the high risk of ice shedding, whereas an undisturbed, normal operation of the wind turbine results in a favourable index number.
The subsequent alteration of the activation state of the de-icing system of the pilot wind turbine(s) may be the switching-on or, also, the switching-off of the de-icing system.
If the alteration of the activation state is the switching-on of the de-icing system, in the case of solid ice accretion requiring stoppage of the wind turbines it can be determined, by means of the pilot wind turbine(s), whether de-icing system is possible at all, before the energy is expended for attempting to de-ice also the other wind turbines of the wind farm. In the case of only slight ice accretion, in which it may be possible to continue to operate the wind turbines of the wind farm, it may be determined, by means of the pilot wind turbine(s), whether the energy expenditure for the de-icing is justified in the case of all wind turbines of the wind farm on the basis of an increase in the power generation that can thereby be achieved. This also applies, in particular, in light-wind situations, in which a wind turbine having ice accretion possibly must not or cannot be operated, but in which a fully de-iced wind turbine would generate power. In this case, it can be ascertained, by means of the pilot wind turbine(s), whether the expected yield of the wind turbines exceeds the energy first required for this purpose. Only if this is the case can it be assumed that it is worthwhile to de-ice also the other wind turbines of a wind farm.
Also in the case of switching-off as alteration of the activation state of the de-icing system, it may be advantageous to perform this firstly on one or more pilot wind turbine(s). A pilot wind turbine can thus be used to check whether, following the switching-off of the de-icing system, there is a renewed occurrence of icing, which then has to be removed again with an increased use of energy. It should be added that, depending on the de-icing system, often a time interval of, for example, 2 hours is prescribed between the switching-off and a re-starting of the system.
In this time interval, a wind turbine can only generate power to a limited extent, or cannot generate power at all. Thus, by means of the pilot wind turbine(s), it can be checked whether switching-off of the de-icing systems is appropriate in the case of the wind turbines of a wind ¨ 4 -farm, or whether the energy required for the operation of the de-icing systems should continue to be expended.
After the activation state of the de-icing system of the pilot wind turbine(s) has been altered, then - as before - the operating state of the pot wind turbine(s) is determined. Since an alteration of the activation state of the de-icing system does not normally directly affect the operating state of a wind turbine, apart from the alteration of the internal demand, a time interval can be provided between the alteration of the activation state of the de-icing system and the subsequent evaluation of the operating state of the wind turbine. The time interval in io this case may be fixed, either globally or individually for each type of alteration of the activation state of the de-icing system. In particu!ar in the case of the switching-on of the de-icing system, however, it is also possible, following alteration of the activation state of the de-icing system, to continuously monitor the operating state of the corresponding wind turbine and, if it is ascertained that there is no further change in the evaluation, to use the last determined .. evaluation of the operating state of the wind turbine.
The evaluation of the operating state of the pot wind turbine(s) from before the alteration of the activation state of the de-icing system i then compared with that after the alteration. If an improvement is ascertained in this case, the alteration of the activation state of the de-icing system performed in the case of the pot wind turbine or turbines can subsequently be transferred to those further wind turbines of the wind farm that do not constitute the pilot wind turbines. It is to be assumed in this case that, owing to the geographical proximity and consequently comparable weather conditions, the operating states of the de-icing systems of the wind turbines in a wind farm are the same, such that, at this time point, the de-icing systems of the further wind turbines in the same activation state as the de-icing system of the pilot wind turbine(s) before it was altered.
If more than one further wind turbine is provided, it is in principle possible for the activation state of the respective de-icing system to be altered, in the form of ,a switch-off, simultaneously in the case of all further wind turbines. However, it may be advantageous to switch off the de-icing systems of the individual wind turbine ;r, a etaggered manner, in order to avoid an excessive reaction on the electricity supply grid because of the normally not inconsiderable load loss upon the switching-off of dc-icing systems , . , In order comparably to avoid unwanted reactions on the grid upon switching-on of the de-icing systems of the further wind turbines, wed/or in order to ensure that the de-icing is effected exclusively with energy generated by the wind farm itself, it is preferred if, in this case, the de-.
icing systems of the further wind turbines is effected in a staggered manner, such that the total . , energy consumption for the de-icing doe's not exceed a predefined or determinable limit value.
The limit value May either be fixed (e.g. by the grid 'operator) or may result directly from the generated power from the wind park at a particular instant, or may be in conformity with this power. Thus, in principle, it can be ensured, for example, that the de-icing is effected only with the power generated in the wind farm itself. It may further be preferred in this case if a fixed io lower limit, at which at least respectively one wind turbine can be de-iced, is defined for the limit value determined in dependence on the generated power. Even if, in the case of insufficient energy generation by the wind farm'itself;the energy required for this must then be drawn at least partly from the grid, it can thus at least be ensured that the de-icing of the wind farm is effected even if it itself at a particular instant does not generate sufficient energy for the de-icing of an individual wind turbine.
If only a staggered switching-on of the de-icing system of the further wind turbines is possible, it is preferred to perform an evaluation of the operating state of all further wind turbines - as described above - and to switch on the de-icing systems of those wind turbine having a lower evaluation of the operating state before the de-icing systems of the wind turbines having a higher evaluation of the operating state. This measure achieves the effect that those wind turbines for which a de-icing can be expected to result in a significantly greater improvement of the operating state, and therefore normally a greater increase in the power generation, than those wind turbines that, despite a de-icing system not yet having been switched on, have a .. better evaluation of their operating state. are switched on first.
It is possible for the pilot wind turbine(s) for a wind farm to be specified in a fixed manner.
Alternatively, it is possible for. the pilot wind turbine(s) of the wind farm to be selected in a variable manner in dependence on the wind direction, the hub height above ground and/or above mean sea level, and on the position in the wind farm. Thus, there may be selected, for example, a pilot wind turbine that receives the wind directly, and in particular without being influenced by further wind turbines of the wind farm, and a further pilot wind turbine, on the opposite side of the wind farm, that is reached only by wind influenced by the other wind turbines. The alteration of the activation state of the de-icing system in the case of these two , exemplarily mentioned pilot wind turbines can have quite different effects upon the evaluation of the operating state of the respective wind turbines.
The wind turbines of a wind farm may be combined in groups, within which the activation state of the de-icing system is altered jointly in each case. It may be provided in this case that one or more pilot wind turbines are defined for each of the groups, such that, in the case of improvement in the evaluation of the operating state of a pilot wind turbine, by alteration of the activation state of the de-icing system, this alteration is transferred in the case of the wind turbines of the associated group. This is advantageous, in particular, in the case of larger wind farms, in which the risk of ice accretion can differ over the wind farm.
For explanation of the wind farm according to the invention and the computer program product according to the invention, reference is made to the statements given above.
The coordinated control of the activation state of the de-icing systems of the wind turbines of the wind farm may be realized, for example, by the control unit of one of the wind turbines or by a central wind-farm controller. It is also possible to effect the control as a distributed system over a plurality of control means of one or more wind turbines and/or of a wind-farm master.
The invention is now described in greater detail on the basis of an advantageous exemplary embodiment, with reference to the appended drawings. There are shown:
Figure 1: a schematic representation of a wind farm according to the invention, in which the method according to the invention is executed.
Represented in Figure 1 is a wind farm 1 according to the invention having a plurality of wind turbines 2. Via a grid 3 that is internal to the wind farm, the wind turbines
The invention relates to a method for operating a wind farm, and to a wind farm designed to execute this method, and to a corresponding computer program product.
Wind farms, comprising a plurality of wind turbines that are technically connected, at least partly, for example, by means of a transmission line grid that is internal to the wind farm, are known from the prior art.
It is furthermore known that, in certain weather conditions, there is the risk that outer parts of wind turbines, in particular their rotor blades, can ice over. If the rotor blades become iced over, their very precisely calculated and manufactured shape is altered, such that the aerodynamics on the rotor blades is impaired. This regularly not only results in yield losses but, in the case of uneven ice accretion on the individual rotor blades, can also result in unbalance of the rotor and in vibrations that can damage the wind turbine.
Finally, there is also the risk that, upon further operation, ice formed on the rotor blades is spun out as a result of the considerable centrifugal forces, and can cause injury to persons or damage to property, even at some distance from the wind turbine.
To enable wind turbines to be operated even in weather conditions in which there is a risk of ice accretion, in order thus to avoid a complete yield failure, it is known to de-ice the rotor blades by heating. The heating may be effected by resistance heating elements distributed over the rotor blades, or by blowing hot air into the largely hollow rotor blades. Irrespective of the type of de-icing, this requires a considerable expenditure of energy.
In the prior art, the de-icing is switched on and off by the control system of wind turbine that may be affected, according to a predefined feedback control scheme, but without the possibility of ensuring beforehand that de-icing is actually possible, or that the yield of the wind turbine will increase by an amount that justifies the energy demand required for the de-icing.
In particular, in the case of the de-icing of a plurality of wind turbines of a wind farm, the de-icing of all wind turbines is very cost-intensive, owing to the amount of energy required for this.
This applies, in particular, if the energy required for this cannot be raised by the wind farm itself, but has to be drawn from the electricity supply grid. The problems mentioned above in relation to individual wind turbines can thus multiply further in the case of a wind farm.
The invention is based on the object of creating a method for operating a wind farm, and a wind farm designed to execute this method, in which the stated problems from the prior art no longer occur, or occur only to a reduced extent.
This object is achieved by a method according to the main claim, and by a wind farm according to claim 8, and by a computer program product according to claim 10.
Advantageous io developments are provided by the dependent claims.
Accordingly, the invention relates to a method for operating a wind farm comprising at least two wind turbines, which each have a de-icing system for the rotor blades of the respective wind turbine, the alteration of the activation state of the de-icing systems of the wind turbines of the wind farm being controlled in a coordinated manner, and comprising the steps:
e) evaluating the operating state of at least one pilot wind turbine selected from the wind turbines of the wind farm;
f) altering the activation state of the de-icing system in the case of the at least one pilot wind turbine;
g) evaluating over again the operating state of the at least one pilot wind turbine; and h) if an improvement is ascertained in the evaluation of the operating state in the case of at least one pilot wind turbine, altering the activation state of the de-icing system of at least one further wind turbine of the wind farm.
Furthermore, the invention relates to a wind farm comprising a plurality of wind turbines connected to a grid that is internal to the wind farm, each having a rotor and a de-icing system for the rotor blades of the rotor, the wind farm being designed to execute the method according to the invention.
¨ 2 -The invention additionally relates to a computer program product, comprising program parts that are designed, when loaded in a computer, preferably the system controller of a wind turbine or a central wind-farm controller, to execute the method according to the invention.
The invention is based on the recognition that, in comparison with the prior art, clear advantages are obtained from a coordinated control of the de-icing systems of the wind turbines of a wind farm. It is sufficient in this case if this control coordinates only the activation state of the individual de-icing systems - i.e. whether, basically, they are switched on or switched off - while the further feedback control and monitoring of the de-icing system, for io example in respect of the temperature, can be effected by the respective system controller of the individual wind turbines, in a manner comparable to the prior art.
By appropriate control it is possible to alter the activation state of the de-icing system - whether then by switching on or switching off - initially in the case of one or more -but not all - wind .. turbines of the wind farm, as so-called pilot wind turbines, and to check on these pilot wind turbines whether the performed alteration of the activation state results in an improvement in their operation. In the case of extensive ice accretion that prohibits the operation of a wind turbine, it may be the case that it is only possible for a pilot wind turbine to be put into operation at all by the activation of the de-icing system. It is only when the operating state improves by a sufficient amount in the case of the pilot wind turbine or turbines that the alteration of the activation state of the de-icing system effected there is also effected in the case of the other wind turbines of the wind farm that do not constitute pilot wind turbines.
To enable ascertainment of a possible improvement in the operating state of a pilot wind turbine, by alteration of the activation state of the de-icing system, the operating state of the pilot wind turbine is evaluated before the said alteration. For this purpose, various operating characteristic numbers such as, for example, the current generated power, the efficiency of the wind turbine (i.e. the ratio of wind power to generated power) or the internal consumption of the wind turbine (i.e. the internal consumption of the components required for the operation of the wind turbine), may be taken into account. Factors relating to the operational safety of the wind turbine that result, for example, from rotor unbalances and/or the risk of ice shedding, may also be taken into account.
¨ 3 -All factors to be taken into account in the evaluation of the operating state of the wind turbine may be weighted and combined in an index number. If the wind turbine is stopped at the time of evaluation of the operating state, for example because of a high risk of ice shedding, this results in an unfavourable index number, both because of absence of power infeed and owing to the high risk of ice shedding, whereas an undisturbed, normal operation of the wind turbine results in a favourable index number.
The subsequent alteration of the activation state of the de-icing system of the pilot wind turbine(s) may be the switching-on or, also, the switching-off of the de-icing system.
If the alteration of the activation state is the switching-on of the de-icing system, in the case of solid ice accretion requiring stoppage of the wind turbines it can be determined, by means of the pilot wind turbine(s), whether de-icing system is possible at all, before the energy is expended for attempting to de-ice also the other wind turbines of the wind farm. In the case of only slight ice accretion, in which it may be possible to continue to operate the wind turbines of the wind farm, it may be determined, by means of the pilot wind turbine(s), whether the energy expenditure for the de-icing is justified in the case of all wind turbines of the wind farm on the basis of an increase in the power generation that can thereby be achieved. This also applies, in particular, in light-wind situations, in which a wind turbine having ice accretion possibly must not or cannot be operated, but in which a fully de-iced wind turbine would generate power. In this case, it can be ascertained, by means of the pilot wind turbine(s), whether the expected yield of the wind turbines exceeds the energy first required for this purpose. Only if this is the case can it be assumed that it is worthwhile to de-ice also the other wind turbines of a wind farm.
Also in the case of switching-off as alteration of the activation state of the de-icing system, it may be advantageous to perform this firstly on one or more pilot wind turbine(s). A pilot wind turbine can thus be used to check whether, following the switching-off of the de-icing system, there is a renewed occurrence of icing, which then has to be removed again with an increased use of energy. It should be added that, depending on the de-icing system, often a time interval of, for example, 2 hours is prescribed between the switching-off and a re-starting of the system.
In this time interval, a wind turbine can only generate power to a limited extent, or cannot generate power at all. Thus, by means of the pilot wind turbine(s), it can be checked whether switching-off of the de-icing systems is appropriate in the case of the wind turbines of a wind ¨ 4 -farm, or whether the energy required for the operation of the de-icing systems should continue to be expended.
After the activation state of the de-icing system of the pilot wind turbine(s) has been altered, then - as before - the operating state of the pot wind turbine(s) is determined. Since an alteration of the activation state of the de-icing system does not normally directly affect the operating state of a wind turbine, apart from the alteration of the internal demand, a time interval can be provided between the alteration of the activation state of the de-icing system and the subsequent evaluation of the operating state of the wind turbine. The time interval in io this case may be fixed, either globally or individually for each type of alteration of the activation state of the de-icing system. In particu!ar in the case of the switching-on of the de-icing system, however, it is also possible, following alteration of the activation state of the de-icing system, to continuously monitor the operating state of the corresponding wind turbine and, if it is ascertained that there is no further change in the evaluation, to use the last determined .. evaluation of the operating state of the wind turbine.
The evaluation of the operating state of the pot wind turbine(s) from before the alteration of the activation state of the de-icing system i then compared with that after the alteration. If an improvement is ascertained in this case, the alteration of the activation state of the de-icing system performed in the case of the pot wind turbine or turbines can subsequently be transferred to those further wind turbines of the wind farm that do not constitute the pilot wind turbines. It is to be assumed in this case that, owing to the geographical proximity and consequently comparable weather conditions, the operating states of the de-icing systems of the wind turbines in a wind farm are the same, such that, at this time point, the de-icing systems of the further wind turbines in the same activation state as the de-icing system of the pilot wind turbine(s) before it was altered.
If more than one further wind turbine is provided, it is in principle possible for the activation state of the respective de-icing system to be altered, in the form of ,a switch-off, simultaneously in the case of all further wind turbines. However, it may be advantageous to switch off the de-icing systems of the individual wind turbine ;r, a etaggered manner, in order to avoid an excessive reaction on the electricity supply grid because of the normally not inconsiderable load loss upon the switching-off of dc-icing systems , . , In order comparably to avoid unwanted reactions on the grid upon switching-on of the de-icing systems of the further wind turbines, wed/or in order to ensure that the de-icing is effected exclusively with energy generated by the wind farm itself, it is preferred if, in this case, the de-.
icing systems of the further wind turbines is effected in a staggered manner, such that the total . , energy consumption for the de-icing doe's not exceed a predefined or determinable limit value.
The limit value May either be fixed (e.g. by the grid 'operator) or may result directly from the generated power from the wind park at a particular instant, or may be in conformity with this power. Thus, in principle, it can be ensured, for example, that the de-icing is effected only with the power generated in the wind farm itself. It may further be preferred in this case if a fixed io lower limit, at which at least respectively one wind turbine can be de-iced, is defined for the limit value determined in dependence on the generated power. Even if, in the case of insufficient energy generation by the wind farm'itself;the energy required for this must then be drawn at least partly from the grid, it can thus at least be ensured that the de-icing of the wind farm is effected even if it itself at a particular instant does not generate sufficient energy for the de-icing of an individual wind turbine.
If only a staggered switching-on of the de-icing system of the further wind turbines is possible, it is preferred to perform an evaluation of the operating state of all further wind turbines - as described above - and to switch on the de-icing systems of those wind turbine having a lower evaluation of the operating state before the de-icing systems of the wind turbines having a higher evaluation of the operating state. This measure achieves the effect that those wind turbines for which a de-icing can be expected to result in a significantly greater improvement of the operating state, and therefore normally a greater increase in the power generation, than those wind turbines that, despite a de-icing system not yet having been switched on, have a .. better evaluation of their operating state. are switched on first.
It is possible for the pilot wind turbine(s) for a wind farm to be specified in a fixed manner.
Alternatively, it is possible for. the pilot wind turbine(s) of the wind farm to be selected in a variable manner in dependence on the wind direction, the hub height above ground and/or above mean sea level, and on the position in the wind farm. Thus, there may be selected, for example, a pilot wind turbine that receives the wind directly, and in particular without being influenced by further wind turbines of the wind farm, and a further pilot wind turbine, on the opposite side of the wind farm, that is reached only by wind influenced by the other wind turbines. The alteration of the activation state of the de-icing system in the case of these two , exemplarily mentioned pilot wind turbines can have quite different effects upon the evaluation of the operating state of the respective wind turbines.
The wind turbines of a wind farm may be combined in groups, within which the activation state of the de-icing system is altered jointly in each case. It may be provided in this case that one or more pilot wind turbines are defined for each of the groups, such that, in the case of improvement in the evaluation of the operating state of a pilot wind turbine, by alteration of the activation state of the de-icing system, this alteration is transferred in the case of the wind turbines of the associated group. This is advantageous, in particular, in the case of larger wind farms, in which the risk of ice accretion can differ over the wind farm.
For explanation of the wind farm according to the invention and the computer program product according to the invention, reference is made to the statements given above.
The coordinated control of the activation state of the de-icing systems of the wind turbines of the wind farm may be realized, for example, by the control unit of one of the wind turbines or by a central wind-farm controller. It is also possible to effect the control as a distributed system over a plurality of control means of one or more wind turbines and/or of a wind-farm master.
The invention is now described in greater detail on the basis of an advantageous exemplary embodiment, with reference to the appended drawings. There are shown:
Figure 1: a schematic representation of a wind farm according to the invention, in which the method according to the invention is executed.
Represented in Figure 1 is a wind farm 1 according to the invention having a plurality of wind turbines 2. Via a grid 3 that is internal to the wind farm, the wind turbines
2 are connected to a substation 4, from which the electric power generated by the wind turbines 2 is fed into a public electricity supply grid 5.
Additionally part of the substation 4 is a wind-farm master, as a central wind-farm controller 6 for functions of the wind farm 1 and of its wind turbines 2 that are to be controlled centrally.
The wind-farm master 6 is connected to the wind-turbine controllers (not represented) of the individual wind turbines 2 via control lines 7.
¨ 7 ¨
The wind turbines 2 each comprise a rotor 21, which rotates, about a substantially horizontal axis, on a nacelle 20, and which has three rotor blades 22 in each case.
Provided on the rotor blades 22, as part of a de-icing system 23, are resistance heating elements, which are controlled, for example, by the system controller of the respective wind turbine 2 or by a separate module. The activation state of the de-icing systems 23 of the individual wind turbines can also be controlled by the wind-farm master 6, according to the method described below.
As an alternative to this, it is also possible in principle for this function to be performed by the system controller of one of the wind turbines 2.
For the following explanation of the method according to the invention, it is assumed that, initially, there are no weather conditions causing ice accretion, and consequently the de-icing systems 23 of all wind turbines 2 are switched off.
Starting from this, in the present example there is to be ice accretion on the rotor blades 22 of the wind turbines 2 following a change in the weather conditions. As is known from the prior art, this ice accretion can be ascertained by the system controller of the individual wind turbines and signalled to the wind-farm master 6.
The wind-farm master 6 thereupon determines, as a pilot wind turbine 2', the wind turbine 2 of the wind farm that is positioned foremost in the current wind direction, and evaluates its operating state. For this purpose, the instantaneous efficiency, the internal consumption, the vibrations in the wind turbine and the risk of ice shedding are weighted and combined in an index number.
The de-icing system 23 of the pilot wind turbine 2' is then switched on, and an evaluation of the operating state of the pilot wind turbine 2' is performed at prescribed time intervals. If the evaluation of the operating state of the pilot wind turbine 2' does not change further, it may be assumed that the de-icing is either completed or - if there is absolutely no detectable change in the evaluation - is not possible.
The last evaluation of the operating state of the pilot wind turbine 2' that was performed is then compared with the evaluation of its operating state before the alteration of the activation state of the de-icing system 23- namely, the switching-on of the latter. If, for example, the difference between the corresponding index numbers exceeds a predefined maximum value, the de-icing ¨ 8 -of the pilot wind turbine 2' is evaluated as sufficiently advantageous such that, in principle, the further wind turbines 2 of the wind farm 1 should also be de-iced.
The alteration of the activation state of the de-icing system 23 of the further wind turbines 2 of the wind farm 1 is effected in a staggered manner, such that the energy generated by the wind farm 1 is not exceeded for the de-icing of the wind turbines 2 having a switched-on de-icing system 23. Thus, for example, because of the increased energy generation of the pilot wind turbine 2' that has already been de-iced, at first the de-icing system 23 of one further wind turbine 2 can be switched on. Once this wind turbine 2 likewise is completely de-iced, the further power increase, as considered over the wind farm 1, may be sufficient to simultaneously de-ice two further wind turbines 2 in the next step, etc. At the end of the staggered switch-on, the de-icing systems 23 of all wind turbines 2 of the wind farm 1 have been activated. If the weather conditions change again at a later point in time, it can be ascertained, by means of the pilot wind turbine 2', whether the de-icing systems 23 of the wind turbines 2 of the wind .. farm 1 can be switched off again.
For this purpose, as described previously, the operating state of the pilot wind turbine 2' is first determined, and its de-icing system 23 is then switched off. After some time, the operating state is again determined, and it is checked whether this has improved. Since the evaluation includes both the switching-off of the de-icing system 23, in the form of a reduction of the internal consumption of the pilot wind turbine 2', and a possible renewed ice accretion, by way of the vibrations in the pilot wind turbine 2', and the risk of ice shedding, the possible advantages and disadvantages of the switching-off of the de-icing system 23 are weighed against each other.
If it is ascertained that the switch-off of the de-icing system 23 of the pilot wind turbine 2' results in no improvement or, on the contrary, in a deterioration of the operating state, the de-icing system 23 of the pilot wind turbine 2' is reactivated again. If, on the other hand, it is ascertained that the switching-off of the de-icing system 23 is advantageous - for example, because the internal consumption of the pilot wind turbine 2' can be reduced considerably without renewed ice accretion occurring as a result - the corresponding alteration of the activation state of the de-icing system 23 can be transferred to the further wind turbines 2.
¨ 9 -The switch-off of the de-icing systems 23 of the further wind turbines 2 in this case is likewise effected in a staggered manner, so that there is no unwanted reaction in the electricity supply grid 5 if there is a sudden large drop in the internal consumption of the entire wind farm 1, or if the power fed into the grid 5 increases abruptly as a result.
Additionally part of the substation 4 is a wind-farm master, as a central wind-farm controller 6 for functions of the wind farm 1 and of its wind turbines 2 that are to be controlled centrally.
The wind-farm master 6 is connected to the wind-turbine controllers (not represented) of the individual wind turbines 2 via control lines 7.
¨ 7 ¨
The wind turbines 2 each comprise a rotor 21, which rotates, about a substantially horizontal axis, on a nacelle 20, and which has three rotor blades 22 in each case.
Provided on the rotor blades 22, as part of a de-icing system 23, are resistance heating elements, which are controlled, for example, by the system controller of the respective wind turbine 2 or by a separate module. The activation state of the de-icing systems 23 of the individual wind turbines can also be controlled by the wind-farm master 6, according to the method described below.
As an alternative to this, it is also possible in principle for this function to be performed by the system controller of one of the wind turbines 2.
For the following explanation of the method according to the invention, it is assumed that, initially, there are no weather conditions causing ice accretion, and consequently the de-icing systems 23 of all wind turbines 2 are switched off.
Starting from this, in the present example there is to be ice accretion on the rotor blades 22 of the wind turbines 2 following a change in the weather conditions. As is known from the prior art, this ice accretion can be ascertained by the system controller of the individual wind turbines and signalled to the wind-farm master 6.
The wind-farm master 6 thereupon determines, as a pilot wind turbine 2', the wind turbine 2 of the wind farm that is positioned foremost in the current wind direction, and evaluates its operating state. For this purpose, the instantaneous efficiency, the internal consumption, the vibrations in the wind turbine and the risk of ice shedding are weighted and combined in an index number.
The de-icing system 23 of the pilot wind turbine 2' is then switched on, and an evaluation of the operating state of the pilot wind turbine 2' is performed at prescribed time intervals. If the evaluation of the operating state of the pilot wind turbine 2' does not change further, it may be assumed that the de-icing is either completed or - if there is absolutely no detectable change in the evaluation - is not possible.
The last evaluation of the operating state of the pilot wind turbine 2' that was performed is then compared with the evaluation of its operating state before the alteration of the activation state of the de-icing system 23- namely, the switching-on of the latter. If, for example, the difference between the corresponding index numbers exceeds a predefined maximum value, the de-icing ¨ 8 -of the pilot wind turbine 2' is evaluated as sufficiently advantageous such that, in principle, the further wind turbines 2 of the wind farm 1 should also be de-iced.
The alteration of the activation state of the de-icing system 23 of the further wind turbines 2 of the wind farm 1 is effected in a staggered manner, such that the energy generated by the wind farm 1 is not exceeded for the de-icing of the wind turbines 2 having a switched-on de-icing system 23. Thus, for example, because of the increased energy generation of the pilot wind turbine 2' that has already been de-iced, at first the de-icing system 23 of one further wind turbine 2 can be switched on. Once this wind turbine 2 likewise is completely de-iced, the further power increase, as considered over the wind farm 1, may be sufficient to simultaneously de-ice two further wind turbines 2 in the next step, etc. At the end of the staggered switch-on, the de-icing systems 23 of all wind turbines 2 of the wind farm 1 have been activated. If the weather conditions change again at a later point in time, it can be ascertained, by means of the pilot wind turbine 2', whether the de-icing systems 23 of the wind turbines 2 of the wind .. farm 1 can be switched off again.
For this purpose, as described previously, the operating state of the pilot wind turbine 2' is first determined, and its de-icing system 23 is then switched off. After some time, the operating state is again determined, and it is checked whether this has improved. Since the evaluation includes both the switching-off of the de-icing system 23, in the form of a reduction of the internal consumption of the pilot wind turbine 2', and a possible renewed ice accretion, by way of the vibrations in the pilot wind turbine 2', and the risk of ice shedding, the possible advantages and disadvantages of the switching-off of the de-icing system 23 are weighed against each other.
If it is ascertained that the switch-off of the de-icing system 23 of the pilot wind turbine 2' results in no improvement or, on the contrary, in a deterioration of the operating state, the de-icing system 23 of the pilot wind turbine 2' is reactivated again. If, on the other hand, it is ascertained that the switching-off of the de-icing system 23 is advantageous - for example, because the internal consumption of the pilot wind turbine 2' can be reduced considerably without renewed ice accretion occurring as a result - the corresponding alteration of the activation state of the de-icing system 23 can be transferred to the further wind turbines 2.
¨ 9 -The switch-off of the de-icing systems 23 of the further wind turbines 2 in this case is likewise effected in a staggered manner, so that there is no unwanted reaction in the electricity supply grid 5 if there is a sudden large drop in the internal consumption of the entire wind farm 1, or if the power fed into the grid 5 increases abruptly as a result.
Claims (10)
1 Method for operating a wind farm (1) comprising at least two wind turbines (2), which each have a de-icing system (23) for the rotor blades (22) of the respective wind turbine (2), characterized in that the alteration of the activation state of the de-icing systems (23) of the wind turbines (2) of the wind farm (1) is controlled in a coordinated manner, and comprises the steps a) evaluating the operating state of at least one pilot wind turbine (2') selected from the wind turbines (2) of the wind farm (1);
b) altering the activation state of the de-icing system (23) in the case of the at least one pilot wind turbine (2');
c) evaluating over again the operating state of the at least one pilot wind turbine (2'), and d) if an improvement is ascertained in the evaluation of the operating state in the case of at least one pilot wind turbine (2'), altering the activation state of the de-icing system (23) of at least one further wind turbine (2) of the wind farm (1).
b) altering the activation state of the de-icing system (23) in the case of the at least one pilot wind turbine (2');
c) evaluating over again the operating state of the at least one pilot wind turbine (2'), and d) if an improvement is ascertained in the evaluation of the operating state in the case of at least one pilot wind turbine (2'), altering the activation state of the de-icing system (23) of at least one further wind turbine (2) of the wind farm (1).
2. Method according to Claim 1, characterized in that the power generation, the internal consumption and/or the operational safety, preferably the rotor unbalance and/or the risk of ice shedding, are taken into account in the evaluation of the operating state.
3. Method according to either one of the preceding claims, characterized in that the alteration of the activation state of the de-icing system (23) is the switching-on or the switching-off of the de-icing system (23).
4. Method according to any one of the preceding claims, characterized in that the alteration of the activation state of the de-icing system (23) is effected in a staggered manner in the case of more than one further wind turbine (2) of the wind ¨ 11 ¨
farm (1), wherein, in the case of switching-on of the de-icing system (23) as alteration of the activation state, in the case of the individual further wind turbines (2), staggering is preferably effected in such a manner that the total energy consumption for the de-icing does not exceed a limit value
farm (1), wherein, in the case of switching-on of the de-icing system (23) as alteration of the activation state, in the case of the individual further wind turbines (2), staggering is preferably effected in such a manner that the total energy consumption for the de-icing does not exceed a limit value
5. Method according to the preceding claim, characterized in that an evaluation of the operating state of all further wind turbines (2) is effected, and the de-icing systems (23) of those wind turbines having a lower evaluation of the operating state are switched on before the de-icing systems (23) of the wind turbines (2) having a higher evaluation of the operating state.
6. Method according to any one of the preceding claims, characterized in that the at least one pilot wind turbine (2') of the wind farm (1) is selected in a variable manner, in dependence on the wind direction, the hub height above ground and/or above mean sea level, and on the position in the wind farm (1), or is specified in a fixed manner
7. Method according to any one of the preceding claims, characterized in that a plurality of wind turbines (2) of the wind farm (1) are combined in groups, in which the activation state of the de-icing systems (23) are altered jointly.
8 Wind farm (1), comprising a plurality of wind turbines connected (2) to a grid (3) that is internal to the wind farm, each having a rotor (21) and a de-icing system (23) for the rotor blades (22) of the rotor (21), characterized in that the wind farm (1) is designed to execute a method according to any one of the preceding claims.
9. Wind farm according to Claim 8, characterized in that the system controller of one of the wind turbines (2) of the wind farm (1) or a central wind-farm controller (6) is designed to control the activation state of the de-icing system (23) of the wind turbines (2) in a coordinated manner.
10. Computer program product, comprising program parts that are designed, when loaded in a computer, preferably the system controller (20) of a wind turbine (1) or a central wind-farm controller (6), to execute the method according to any one of Claims 1 to 7.
¨ 12 ¨
¨ 12 ¨
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102017010608.8 | 2017-11-16 | ||
| DE102017010608.8A DE102017010608A1 (en) | 2017-11-16 | 2017-11-16 | Method for operating a wind farm and wind farm |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA3023914A1 true CA3023914A1 (en) | 2019-05-16 |
| CA3023914C CA3023914C (en) | 2021-09-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3023914A Active CA3023914C (en) | 2017-11-16 | 2018-11-13 | Method for operating a wind farm, and wind farm |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP3486479B1 (en) |
| CA (1) | CA3023914C (en) |
| DE (1) | DE102017010608A1 (en) |
| DK (1) | DK3486479T3 (en) |
| ES (1) | ES2837327T3 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113323805B (en) * | 2021-05-27 | 2023-03-24 | 中国电建集团江西省电力设计院有限公司 | Method for improving operation efficiency of fan during icing period of wind power plant |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102010015595A1 (en) * | 2010-04-19 | 2011-10-20 | Aloys Wobben | Method for operating wind energy plant for use with aerodynamic rotor with rotor blade for use in wind farm, involves operating wind energy plant at operating point that is dependent on wind speed |
| ES2605484T3 (en) * | 2010-04-19 | 2017-03-14 | Wobben Properties Gmbh | Procedure for the operation of a wind power installation |
| US20120226485A1 (en) * | 2011-03-03 | 2012-09-06 | Inventus Holdings, Llc | Methods for predicting the formation of wind turbine blade ice |
| DE102011085107B4 (en) * | 2011-10-24 | 2013-06-06 | Wobben Properties Gmbh | Method for controlling a wind energy plant |
| EP2778404A1 (en) * | 2013-03-14 | 2014-09-17 | Siemens Aktiengesellschaft | Method to de-ice wind turbines of a wind park |
| DE102014223762A1 (en) * | 2014-11-21 | 2016-05-25 | Robert Bosch Gmbh | Method and device for monitoring at least one wind turbine, ensprechende wind turbine and a wind farm |
-
2017
- 2017-11-16 DE DE102017010608.8A patent/DE102017010608A1/en active Pending
-
2018
- 2018-11-13 CA CA3023914A patent/CA3023914C/en active Active
- 2018-11-15 DK DK18206405.5T patent/DK3486479T3/en active
- 2018-11-15 ES ES18206405T patent/ES2837327T3/en active Active
- 2018-11-15 EP EP18206405.5A patent/EP3486479B1/en active Active
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| Publication number | Publication date |
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| CA3023914C (en) | 2021-09-07 |
| EP3486479A1 (en) | 2019-05-22 |
| ES2837327T3 (en) | 2021-06-30 |
| DK3486479T3 (en) | 2020-12-07 |
| EP3486479B1 (en) | 2020-09-09 |
| DE102017010608A1 (en) | 2019-05-16 |
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