JP2013053592A - Wind farm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind farm effectively using rotary energy of all of the wind power generation apparatuses and supplying equalized power of high output to a power system by appropriately controlling generator side torque of the wind power generation apparatuses in the wind farm.SOLUTION: The wind farm is provided with: a plurality of wind power generation apparatuses mounted with controllable power conversion devices; a plurality of anemometers provided to the plurality of wind power generation apparatuses in a combined manner respectively and measuring wind velocity; a plurality of individual control devices which control the plurality of wind power generation apparatuses respectively and acquire and store operation information of the wind power generation apparatuses; and a wind farm control device which controls the whole wind farm and creates command values for controlling the power generator side torque of the wind power generation apparatus after performing treatment by using the operation information of the respective wind power generation apparatuses from the plurality of individual control devices and virtual energy pieces, and transmits the created command values to the individual control devices of the wind power generation apparatuses.

Description

  The present invention relates to wind power generation technology, and in particular, a plurality of wind power generation devices (wind power generation wind turbines) that are equipped with a variable speed generator and a controllable power conversion device and generate wind power using wind energy. The above relates to the installed wind farm (wind power generation system).

  In recent years, a power generation method using natural energy (renewable energy) such as wind power or sunlight has been attracting attention as one of the measures against global warming. Among them, wind power generation that uses wind energy is the most advanced in the world.

  As shown in FIG. 1, an output coefficient Cp is used as an index representing how much wind power can be converted into windmill power for a wind turbine generator. The output coefficient Cp is defined by the ratio of the windmill output to the wind energy. The peripheral speed ratio λ is defined by the ratio of the peripheral speed (tip speed) of the wind turbine blades to the wind speed Vw (radius R of the wind turbine blades × rotor rotational speed ω of the wind turbine blades).

  The output coefficient Cp is known as a function of the peripheral speed ratio λ and the pitch angle θ of the wind turbine blade, and the shape of the function depends on the cross-sectional shape of the wind turbine blade. Various analytical function forms have been proposed from the results of wind tunnel experiments. As shown in FIG. 2, the curve has one maximum point (ie, maximum power point). That is, as can be seen from FIG. 2, there is an optimum rotor speed of the wind turbine blade for a certain wind speed.

  When the wind turbine blades of the wind power generator are rotating at a constant speed, that is, when the wind power generator adopts a constant speed rotating wind power generation system, the circumferential speed ratio changes whenever the wind speed changes. The output will deviate from this maximum power point. Therefore, in the constant speed rotating wind power generation method, the maximum electrical energy (maximum electrical energy that can be taken out by the windmill) cannot be obtained from the wind energy.

  Because there are many pulsations in wind power due to the complexity of weather conditions and topography in Japan, there are few areas in Japan where stable wind resources can be obtained above the rated wind speed of wind power generators compared to overseas.

  In areas with topographic relief, the wind is not always at a constant speed but travels pulsating. In order to more efficiently control (operate) a wind power generator installed in an area where there is a lot of pulsation in such wind power, the constant-speed rotating wind power generation method (constant-speed rotating operation), which is currently the mainstream, is used. It is more effective to use a dynamic control method than

  As a control method for obtaining the maximum electric energy from wind energy under a pulsating wind condition below the rated wind speed of the wind power generator, a dynamic power control method is a maximum power point following operation (MPPT: Maximum Power Point). Track).

  The maximum power point following operation is a method in which the rotor rotational speed of the wind turbine blade of the wind turbine generator is changed in accordance with the fluctuation of the wind, and the maximum value of the output coefficient Cp in the wind turbine characteristics of the wind turbine generator (shown in FIG. 2). The peripheral speed ratio λ is kept constant (the peripheral speed ratio λ value corresponding to the maximum power point as shown in FIG. 2) so that the output coefficient Cp value corresponding to the maximum power point is maintained. It is a control method that can convert wind energy to electric power energy to the maximum by operating.

  Thus, by performing the maximum power point tracking operation, the amount of power generated by the wind turbine generator can be increased. By performing the maximum power point following operation, the conversion efficiency when the wind energy is converted into the power energy becomes higher than when the constant speed rotating wind power generation method is adopted.

  However, there are the following two problems when performing control of maximum power point following operation.

  One problem is that the rotor speed of the wind turbine blade cannot be changed quickly due to the inertia of the wind turbine blade. Usually, the wind speed fluctuates with a period of 1 second to several seconds. Therefore, in order to perform the maximum power point following operation, it is necessary to change the rotor rotational speed of the wind turbine blade in accordance with the fluctuation of the wind speed. However, in a large wind power generator, the inertia of the wind turbine blade is very large, its time constant is several tens of seconds, and it is difficult to always maintain the optimum rotor speed obtained according to the fluctuation of the wind speed, That is, when the wind pulsates, there is a problem that the followability of the maximum power point follow-up operation becomes slow.

  As another problem, when the control of maximum power point following operation is performed, the fluctuation of the output power output from the wind power generator becomes larger than that in the constant speed rotating wind power generation method. In the case where the wind turbine blades of the wind turbine generator are rotating at a constant rotational speed, even if the wind speed changes suddenly, the output coefficient Cp decreases, so that the output power output from the wind turbine generator does not vary so much. However, in the case of the maximum power point following operation, the output coefficient Cp is always the maximum value, so that the output power of the wind turbine generator proportional to the cube of the wind speed is output to the power system.

  In this way, when the power that greatly fluctuates is output from the wind turbine generator that performs the maximum power point tracking operation to the power grid, a power source (for example, a thermal power plant) or a load (factory or household) connected to the power grid is output. Problems such as voltage fluctuations and frequency fluctuations occur.

  As a control method that can solve the above-described two problems, for example, there is a wind power generation facility equipped with a wind power generator and a flywheel generator as described in Patent Document 1.

  The wind power generation facility described in Patent Document 1 enables high-speed charge / discharge of energy, and actively uses the energy of the flywheel to perform follow-up control of the rotational speed of the wind turbine blades of the wind power generator. And proposed “pump-up operation” to efficiently convert wind energy into electrical energy.

  That is, in the wind power generation facility disclosed in Patent Document 1, it is possible to operate the wind power generator as an electric motor by supplying power from the flywheel generator to the wind power generator, and follow the maximum power point. Improves driving tracking and realizes highly efficient control.

Japanese Patent No. 4056713

  However, since the wind power generation facility disclosed in Patent Document 1 requires electric power from the outside of the wind power generator, it is necessary to install a power storage device such as a flywheel generator. Installation of a power storage device such as a flywheel generator also contributes to an increase in the cost of wind power generation facilities.

  In addition, since the wind power generation facility disclosed in Patent Document 1 is composed of a single wind power generation device, the high power conversion efficiency is achieved by the followability of the maximum power point following operation improved by utilizing the energy of the flywheel. However, the fluctuation of the power output from the wind power generator is also more severe than that of the constant-speed rotating wind power generation system. After being smoothed to some extent via the storage device, it is output to the power system as output power.

  The present invention has been made under the circumstances as described above, and an object of the present invention is to provide a generator for a wind power generator in a wind farm that includes a plurality of wind power generators without using a power storage device. Wind farm that effectively uses the rotational energy of all wind power generators in the wind farm, and supplies high power leveled power to the power system by appropriately controlling the side torque Is to provide.

  The present invention relates to a wind farm that generates electric power using wind energy, and the object of the present invention is to provide a plurality of wind power generators having wind turbine blades and mounted with a variable speed generator and a controllable power converter. And a plurality of anemometers that are respectively attached to the plurality of wind turbine generators and control the plurality of wind turbine generators, respectively, and obtain operating information representing the operating state of the wind turbine generators, respectively. A plurality of individual control devices to be stored and the entire wind farm, and after performing processing using the operation information of each wind turbine generator from the plurality of individual control devices and a virtual energy piece Generate a command value for controlling the generator-side torque of the wind turbine generator, and transmit the generated command value to the individual controller of the wind turbine generator Effectively achieved by providing a farm control system.

  In addition, the object of the present invention is to provide the wind farm control device with the wind power generator having the largest output increase when the positive virtual energy piece is given by the processing and the negative virtual energy piece. If the total value of the increased output of the two selected wind power generators is larger than the predetermined energy limit, the generator side torque control process is performed. Or the generator-side torque control processing is more effectively achieved by being performed through the control of the power converter according to the command value generated by the wind farm control device. .

  ADVANTAGE OF THE INVENTION According to this invention, the electric power equalized by the high output can be supplied to an electric power grid | system by utilizing effectively the rotational energy which all the wind power generators installed in the wind farm have.

  Further, by further developing the present invention, it is possible to supply a constant output power without pulsation from the wind farm. This also solves the problem of large output power pulsation, which is a disadvantage of the wind power generation system.

It is a figure for demonstrating the power generation principle of a wind power generator (wind power generator windmill). It is a figure which shows an example of the windmill characteristic of a wind power generator. It is a conceptual diagram for demonstrating a wind power generator installation provided with a flywheel generator and a wind power generator. It is a conceptual diagram for demonstrating control when a wind speed rises rapidly about the pump-up driving | running performed by the wind power generation equipment shown by FIG. It is a conceptual diagram for demonstrating control when the wind speed decelerates rapidly about the pump-up driving | running performed by the wind power generation equipment shown by FIG. It is a conceptual diagram which shows embodiment of the wind farm which concerns on this invention. It is a schematic diagram for demonstrating the wind farm which concerns on this invention. It is a flowchart for demonstrating the process performed with the wind farm control apparatus of the wind farm which concerns on this invention. In the wind farm which concerns on this invention, it is a schematic diagram for demonstrating the process performed with respect to the i-th wind power generator and the j-th wind power generator.

  The present invention appropriately controls the generator-side torque of a wind power generator in a wind farm including a plurality of (two or more) wind power generators equipped with a variable speed generator and a controllable power converter. Thus, the present invention relates to a wind farm that effectively uses the rotational energy of all wind power generators in the wind farm and supplies the power system with high power and leveled power.

  Before going into the detailed description of the present invention, first, the principle of “pump-up operation” disclosed in the wind power generation facility described in Patent Document 1 will be described with reference to FIGS. 3, 4 and 5. 3, 4, and 5 are diagrams for explaining the pump-up operation (pump-up control), the power control device provided in the wind power generation facility of Patent Document 1 is not illustrated. did.

  FIG. 3 is a conceptual diagram for explaining the wind power generation facility described in Patent Document 1. As shown in FIG. 3, a flywheel generator is electrically connected in parallel between the output of the wind turbine generator and the power system. The flywheel generator smoothes fluctuations in power to the power system and performs a pump-up operation for quickly changing the rotor rotational speed of the wind turbine blades for the wind power generator.

  In order to perform the maximum power point following operation, it is necessary to change the rotor rotational speed of the wind turbine blade in accordance with the fluctuation of the wind speed. Although it is possible to change the rotor rotation speed of the wind turbine blade by wind energy, since the inertia of the wind turbine blade is large, a sufficient follow-up speed cannot be obtained only by the wind energy. In the wind power generation facility of Patent Document 1, more generated power (power energy) is obtained by performing control to quickly change the rotor rotational speed of the wind turbine blades using the rotational energy accumulated in the flywheel. Can do.

  FIG. 4 is a conceptual diagram for explaining the control in the case where the wind speed suddenly increases in the pump-up operation performed in the wind power generation facility shown in FIG.

  As shown in FIG. 4, when the wind speed increases rapidly, it is necessary to rapidly increase the rotor rotational speed of the wind turbine blade of the wind turbine generator. In this case, the flywheel generator is operated as a generator, and power is supplied to the wind power generator while sending constant power to the power system. The wind turbine generator is operated as an electric motor, and the rotor rotational speed of the wind turbine blade is quickly increased. That is, the rotational energy accumulated in the flywheel is converted again into the rotational energy of the wind turbine blades through the electrical energy.

  FIG. 5 is a conceptual diagram for explaining control when the wind speed is suddenly reduced in the pump-up operation performed in the wind power generation facility shown in FIG. 3.

  As shown in FIG. 5, when the wind speed is suddenly decelerated, it is necessary to rapidly reduce the rotor rotational speed of the wind turbine blade of the wind turbine generator. In that case, a flywheel generator is driven as an electric motor, and electric power more than input wind force is taken out from a wind power generator. While sending constant power to the power system, the surplus power is stored in the flywheel. As a result, it is possible to increase the load of the wind turbine generator and rapidly reduce the rotor speed. In other words, the rotational energy of the windmill blades is forcibly converted into electric energy and stored as the rotational energy of the flywheel, thereby controlling the rotational speed of the windmill blades.

  Thus, in the pump-up operation, energy is exchanged only between the flywheel and the wind turbine blade, but since the maximum value of the output coefficient Cp of the wind turbine generator can always be maintained, The total generated power from the power generation device is increased as compared with the constant-speed rotating wind power generation method.

  That is, the pump-up operation performed in the wind power generation facility shown in FIG. 3 can be said to be control that can apparently reduce the inertia of the wind turbine blade, which is a mechanical restriction, through electric energy.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to FIGS. 6, 7, 8 and 9.

  FIG. 6 is a conceptual diagram simply showing the configuration of the embodiment (wind farm 10) of the wind farm according to the present invention. FIG. 7 is a schematic diagram for explaining the k-th wind power generator installed in the wind farm 10. FIG. 8 is a flowchart for explaining processing performed in the wind farm control device 20 installed in the wind farm 10. FIG. 9 is a schematic diagram for explaining processing performed on the i-th wind power generator and the j-th wind power generator in the wind farm 10.

As shown in FIGS. 6 and 9, the wind farm 10
A plurality of wind turbine generators 100 each having a wind turbine blade 101 and mounted with a variable speed generator 102 and a controllable power converter 103;
A plurality of anemometers 110 that are respectively attached to the plurality of wind turbine generators 100 and measure the wind speed;
A plurality of individual control devices 120 that respectively control the plurality of wind turbine generators 100 and obtain and store operation information representing the operation state of the wind turbine generators 100;
While controlling the whole wind farm 10, the operation information of each wind power generator 100 memorize | stored in the some individual control apparatus 120 is input, and it processes based on the input operation information of each wind power generator 100 And generating a command value for controlling the generator-side torque of the wind turbine generator 100, and transmitting the generated command value to the individual controller 120 of the wind turbine generator 100,
It has.

  Further, the individual control device 120 controls the generator-side torque of the wind turbine generator 100 according to the command value transmitted from the wind farm control device 20.

  Since FIG. 6 is a conceptual diagram, five wind power generators 100 are conceptually shown. However, the plurality of wind power generators constituting the wind farm of the present invention is limited to five wind power generators. Any of a plurality of wind power generators (for example, N wind power generators) may be used.

  As shown in FIG. 6, in the wind farm 10, each wind power generator 100 is electrically connected by a power transmission line 30, and the voltage level conversion transformer and the like are omitted via the power transmission line 30. The electric power connected to the electric power system 50 and generated by each wind power generator 100 is supplied to the electric power system 50 as the output power of the wind farm 10.

  Further, as shown in FIG. 6, in the wind farm 10, the wind farm control device 20 and each individual control device 120 are connected by a communication line 40 and can communicate with each other. The communication line 40 may be wired or wireless.

  Here, the gist of the present invention will be described.

  As described above, in the wind power generation facility of Patent Document 1, the pump-up operation for exchanging energy is performed between the flywheel of the flywheel generator and the wind turbine blades of the wind power generator.

  In the present invention, the concept of the pump-up operation described above is applied to a wind farm constituted by a plurality of wind power generators without using a power storage device (for example, a flywheel generator).

  In other words, in the present invention, energy is exchanged between the wind turbine blades of the wind turbine generator selected by the processing performed based on the operation information of the wind turbine generator in the wind farm constituted by a plurality of wind turbine generators. Pump-up operation is performed.

  In the present invention, all the wind power generators in the wind farm have the proper control of the generator-side torque of the wind power generator selected by the process performed based on the operation information of the wind power generator. The rotating energy is effectively utilized, and high power and leveled power is supplied to the power system from the entire wind farm.

  In the present invention, first, positive and negative virtual energy pieces having the same absolute value are set.

  Next, when a positive virtual energy piece (+ ΔE) is given to all the wind turbine generators installed in the wind farm, the output of the wind turbine generator increases most (however, the increase amount may be negative). Wind power generator i (i-th wind power generator) is selected.

  That is, the wind power generator having the largest output increase when the positive virtual energy piece (+ ΔE) is given is the i-th wind power generator.

  Here, giving the positive virtual energy piece (+ ΔE) to the wind turbine generator means that the positive virtual energy piece (+ ΔE) is added by + ΔE from the output of the wind turbine generator, thereby increasing the torque of the wind turbine generator. The output of the generator will increase and the rotor speed of the wind turbine blade will decrease.

  In addition, when a negative virtual energy piece (−ΔE) is given to all wind power generators installed in the wind farm, the output of the wind power generator increases the most (however, the increase amount may be negative). A wind power generator j (j-th wind power generator) is selected.

  That is, the wind power generator having the largest output increase when the negative virtual energy piece (−ΔE) is given is the j-th wind power generator.

  Here, giving a negative virtual energy piece (−ΔE) to the wind turbine generator means reducing the torque of the wind turbine generator. By applying a negative virtual energy piece (−ΔE) to the wind turbine generator, the torque of the generator can be reduced, the output can be lowered, and the rotor speed of the wind turbine blade of the wind turbine generator can be increased.

The increase in output of the i-th wind power generator when a positive virtual energy fragment is given (ΔP _i ^{+ max} ), and the increase in output of the j-th wind power generator when a negative virtual energy fragment is given ( When the total value of ΔP _j ^−max ) is larger than a predetermined energy limit P _lim (where P _lim > 0), the generator-side torque of the i-th wind power generator has a positive virtual energy piece (+ ΔE). ) Is controlled to the generator-side torque (Tg ^* ), and the generator-side torque of the j-th wind generator is negative virtual energy. The j-th wind power generator is controlled so that the generator side torque (Tg ^* ) after the piece (−ΔE) is given.

  Such a process is repeated for all wind power generators installed in the wind farm until there is no longer the pair (i, j) of the i-th wind power generator and the j-th wind power generator.

  As a result, all the wind turbine generators have a proper control of the generator-side torque of the wind turbine generator in the wind farm composed of a plurality of wind turbine generators without using the power storage device. It is possible to effectively use the rotational energy that is present, and thus to dynamically control all wind power generators in the wind farm.

  Here, the k-th wind power generator in the case where the wind farm 10 according to the present invention is a wind farm composed of N wind power generators 100 will be described with reference to FIG. Further, processing performed by the wind farm control device 20 of the wind farm 10 of the present invention constituted by the N wind power generators 100 will be described with reference to FIGS. 8 and 9.

  First, symbols used in the description to be described later will be described.

  k, i, j are indexes of a plurality of wind power generators 100 constituting the wind farm 10 of the present invention. k means the k-th wind power generator, i means the i-th wind power generator, and j means the j-th wind power generator.

Vw is the wind speed measured by the anemometer 110. Vw _k is the wind speed measured by the anemometer 110 provided in the k-th wind power generator. θ is the pitch angle of the rotor blades of the wind turbine generator 100. θ _k is the pitch angle of the rotor blades of the k-th wind power generator.

ΔE is a piece of virtual energy. + ΔE is a positive virtual energy piece, and −ΔE is a negative virtual energy piece. Ρ is the air density. A _k is the swept area of the wind turbine blades of a wind power generator k groups th.

ω is the rotor rotational speed of the rotor blades of the wind power generator 100. ω _k is the rotor rotational speed of the rotor blade of the k-th wind power generator. ω ^* is the rotor rotational speed of the rotor blades of the wind turbine generator 100 after the virtual energy fragment is given. ω _k ^* is the rotor rotational speed of the rotor blade of the k-th wind power generator after the virtual energy piece is given.

Tg is the generator-side torque of the wind turbine generator 100. Tg _k is the generator-side torque of the k-th wind power generator. Tg ^* is the generator-side torque of the wind turbine generator 100 after the virtual energy fragment is given. Tg _k ^* is the generator-side torque of the k-th wind power generator after the virtual energy fragment is given.

Tr is the rotor side torque of the wind turbine generator 100. Tr _k is a rotor-side torque k groups th wind turbine generator. Δt is a time step representing a predetermined time. J is the moment of inertia of the wind turbine generator 100. J _k is the moment of inertia of the k-th wind power generator.

λ is a peripheral speed ratio of the wind turbine generator 100. λ _k is a peripheral speed ratio of the k-th wind power generator. λ ^* is the peripheral speed ratio of the wind turbine generator 100 after the virtual energy fragment is given.
λ _k ^* is a peripheral speed ratio of the k-th wind power generator after the virtual energy piece is given.

Cp is an output coefficient (power coefficient) of the wind turbine generator 100. The output coefficient of the wind turbine generator is determined by the shape of the wind turbine blades of the wind turbine generator. Cp _k is the output coefficient of the wind turbine generator of k groups th. Cp ^* is an output coefficient of the wind turbine generator 100 after the virtual energy fragment is given. Cp _k ^* is an output coefficient of the k-th wind power generator after the virtual energy fragment is given.

ΔP _k ⁺ is an increase in output of the k-th wind power generator when a positive virtual energy piece is given. ΔP _k ⁻ is an increase in output of the k-th wind power generator when a negative virtual energy piece is given. P _lim is a predetermined energy limit. However, P _lim > 0.

ΔP _i ^{+ max} is the value of the _i-th wind power generation device in which the increase in the output of the wind power generation device is maximized when a positive virtual energy piece is given to all the wind power generation devices 100 installed in the wind farm 10. This is the output increase.

ΔP _j ^−max is the _j-th wind power generator that maximizes the output of the wind power generator when negative virtual energy pieces are given to all the wind power generators 100 installed in the wind farm 10. Is the increase in output. However, i ≠ j.

As shown in FIG. 7, when a positive virtual energy piece (+ ΔE) is given to the _k-th wind power generator in the wind farm 10 of the present invention configured by the N wind power generators 100, Tg _k ^* The relationship of ω _k Δt−Tg _k ω _k Δt = + ΔE is established. On the other hand, when a negative virtual energy piece (−ΔE) is given to the k-th wind power generator, the relationship Tg _k ^* ω _k Δt−Tg _k ω _k Δt = −ΔE is established. However, k = 1 to N.

  Here, processing performed by the wind farm control device 20 based on the operation information of the N wind power generation devices 100 will be described. However, k = 1 to N.

  As described above, the wind farm control device 20 inputs the operation information of each wind power generation device 100 stored in each individual control device 120, and performs processing based on the input operation information of each wind power generation device 100. After that, a command value for controlling the generator-side torque of the wind turbine generator 100 is generated, and the generated command value is transmitted to the individual control device 120 of the corresponding wind turbine generator 100.

The wind farm controller 20 includes the wind speed Vw _k of each wind power generator, the rotor rotational speed ω _k of the rotor blades of each wind power generator, the circumferential speed ratio λ _k and the pitch angle θ _{k as} a function of each wind power generator. Operation information such as the output coefficient Cp _k (λ _k , θ _k ) and the inertia moment J _k of each wind turbine generator is required.

  The operation information regarding each wind power generator 100 is acquired by each individual control device 120 that controls each wind power generator 100 and is stored in each individual control device 120.

  Then, the wind farm control device 20 performs processing after inputting the operation information of each wind power generation device 100 stored in each individual control device 120.

The peripheral speed ratio λ _k of the _k-th wind power generator is obtained as shown in Equation 1 below. Here, R _k is the radius of the wind turbine blade of the k-th wind power generator.

また、風力発電装置１００の出力係数（パワー係数）とは、風力発電装置１００の回転面に流入する風の単位時間あたりのエネルギーＰｗと、風力発電装置１００が風から収得できるエネルギーの比であり、風力発電装置１００の風車翼の先端速度と風速の比（周速比）とピッチ角の関数であり、ある周速比の値で最大値をとることが知られている。

The output coefficient (power coefficient) of the wind power generator 100 is the ratio of the energy Pw per unit time of the wind flowing into the rotating surface of the wind power generator 100 and the energy that the wind power generator 100 can obtain from the wind. It is a function of the tip speed / wind speed ratio (peripheral speed ratio) and pitch angle of the wind turbine blades of the wind power generator 100, and it is known that the maximum value is obtained at a certain peripheral speed ratio value.

  However, Pw is obtained as shown in Equation 2 below.

各風力発電装置の運動方程式は、風から受けるトルク（即ち、ロータ側トルクＴｒ）と発電機側トルクＴｇの差が、慣性モーメントＪと各運動量の時間微分の値に等しいことから与えられる。ロータ側トルクＴｒは、風力発電装置の回転面に流入する風のエネルギーに出力係数（パワー係数）を乗じ、回転速度で除算することによって得られる。

The equation of motion of each wind power generator is given by the fact that the difference between the torque received from the wind (ie, the rotor side torque Tr) and the generator side torque Tg is equal to the moment of inertia J and the value of the time derivative of each momentum. The rotor-side torque Tr is obtained by multiplying the energy of wind flowing into the rotating surface of the wind power generator by an output coefficient (power coefficient) and dividing by the rotation speed.

  The generator side torque Tg is obtained by dividing the electrical output by the rotational angular velocity. Further, it is assumed that the generator side torque Tg can be freely controlled by the control of the controllable power converter 103.

Here, the wind farm control device 20 operates information (wind speed Vw _k , rotor rotational speed ω _k , circumferential speed ratio λ _k , pitch angle θ _k) stored in each individual control device 120. , The output coefficient Cp _k and the moment of inertia J _k ) are input, and processing is performed.

  First, a small virtual energy piece ΔE is set. Note that the magnitude of the absolute value of the virtual energy piece ΔE is set based on the calculation function capability of the wind farm control device 20 and the number (N) of wind power generators installed in the wind farm 10.

  At predetermined time intervals Δt, the wind farm control device 20 gives positive virtual energy pieces (+ ΔE) to the N wind turbine generators, respectively. The process in the loop k is a process performed on the k-th wind power generator. The processing for the N wind power generators is the same as the processing in loop k.

  When a positive virtual energy piece (+ ΔE) is given to the k-th wind power generator, the mathematical relationship shown in step S100 in FIG. 8 is established, and + ΔE power is supplied to the k-th wind power generator. Thus, the k-th wind power generator is operated as an electric motor.

  By operating the k-th wind power generator as an electric motor, the rotor rotational speed is increased as shown in the equation shown in Step S110 of FIG. As the rotor speed increases, the value of the peripheral speed ratio changes, and the value of the output coefficient (power coefficient) changes (see the formula shown in step S120 in FIG. 8), so that the energy obtained from the wind energy changes. To do.

As shown in the equation shown in step S130 of FIG. 8, the change in energy obtained by the k-th wind power generator (that is, the output increase ΔP _k ^{+ of the} _k-th wind power generator) is the wind farm control device. 20 can be calculated.

When the loop k from step S100 to step S130 is performed on the N wind power generators, the amount of change in energy obtained is the largest among the N wind power generators (this change may be a negative value). .) Is the _i-th wind power generator, and the change is ΔP _i ^{+ max} . That is, ΔP _i ^{+ max} is an output increase of the i-th wind power generator when a positive virtual energy piece is given.

  Similarly, the wind farm control device 20 applies a negative virtual energy piece (−ΔE) to each of the N wind power generators at predetermined time intervals Δt. The process in the loop k is a process performed on the k-th wind power generator. The processing for the N wind power generators is the same as the processing in loop k.

  When a negative virtual energy piece (−ΔE) is applied to the k-th wind power generator, the mathematical relationship shown in step S200 of FIG. 8 is established, and power of −ΔE is supplied to the k-th wind power generator. As a result, the load on the k-th wind power generator is increased.

  By increasing the load of the k-th wind power generator, the rotational speed of the rotor decreases as in the equation shown in step S210 of FIG. As the rotor speed decreases, the peripheral speed ratio value changes, and the output coefficient (power coefficient) value changes (see the equation shown in step S220 in FIG. 8), so that the energy obtained from the wind energy changes. To do.

As shown in the equation shown in step S230 of FIG. 8, the change in energy obtained by the k-th wind power generator (that is, the output increase ΔP _k ^{− of the} _k-th wind power generator) is the wind farm control device. 20 can be calculated.

When the loop k from step S200 to step S230 is performed on the N wind power generators, the amount of change in energy obtained is the largest among the N wind power generators (this change may be a negative value). .) ^{Is the} _j-th wind power generator, and the change is ΔP _j ^-max . That is, ΔP _j ^−max is an output increase of the j-th wind power generator when a negative virtual energy piece is given.

As described above, ΔP _i ^{+ max} and ΔP _j ^-max were obtained by the processing in the wind farm control apparatus 20.

Next, as shown in step S300 of FIG. 8, when the total value (ΔP _i ^{+ max} + ΔP _j ^−max ) of both is larger than a predetermined energy limit P _lim (where P _lim > 0), wind farm control is performed. In the apparatus 20, a generator side torque control process is performed.

The generator-side torque control process is performed so that the generator-side torque of the i-th wind power generator is the generator-side torque (Tg ^* ) after the positive virtual energy fragment is applied. The j-th wind power generator is controlled so that the generator-side torque of the j-th wind power generator becomes the generator-side torque (Tg ^* ) after the negative virtual energy fragment is applied. It is the process which controls the wind power generator of an eye.

Specifically, as shown in FIG. 9, the wind farm control device 20 calculates the generator-side torque (Tg ^* ) after the positive virtual energy piece is given, and uses the i-th wind power as a command value. The individual control device 120i of the i-th wind power generation device 100i is transmitted to the individual control device 120i of the power generation device 100i, and the i-th wind power generation device 100i is controlled by the power conversion device 103i according to the transmitted command value. The generator side torque of the wind power generator 100i is controlled.

In addition, as shown in FIG. 9, the wind farm control device 20 calculates the generator-side torque (Tg ^* ) after the negative virtual energy piece is given and uses it as a command value to obtain the j-th wind power generation device. The j-th wind power generator 100j transmits the j-th wind power generator 100j to the j-th wind power generator 100j through the control of the power converter 103j according to the transmitted command value. The generator side torque of the device 100j is controlled.

On the other hand, as shown in step S300 of FIG. 8, when the total value (ΔP _i ^{+ max} + ΔP _j ^−max ) of both is equal to or less than a predetermined energy limit P _lim , the wind farm control device 20 performs the next predetermined time. Enter Δt and process.

Thus, the output power of the entire wind farm 10 is improved by controlling the i-th wind power generator and the j-th wind power generator. Note that the value of P _lim is adjusted based on the speed of the calculation function of the wind farm control device 20 and the number (N) of wind power generators installed in the wind farm 10.

  The above processing is repeated for all wind power generators 100 installed in the wind farm 10 until there is no longer the pair (i, j) of the i-th wind power generator and the j-th wind power generator. Thus, the rotational energy of all the wind power generators 100 installed in the wind farm 10 is utilized to the maximum, and the output power from the wind farm 10 is maximized.

  In addition, the value of the generator side torque may become negative by repeating the above process. This is the case of the motor operation (wind pump up operation) of the wind turbine generator proposed in Patent Document 1, and this case is also allowed. However, depending on the configuration of the power converter, there is a case where the reverse flow of power is not possible (for example, when a diode bridge or the like is used). In this case, the present invention can be applied by adding a condition in which the value of the generator-side torque does not become negative in the above processing.

DESCRIPTION OF SYMBOLS 10 Wind farm 20 Wind farm control apparatus 30 Power transmission line 40 Communication line 50 Electric power system 100 Wind power generator 101 Windmill blade 102 Variable speed generator 103 Power converter 110 Anemometer 120 Individual control apparatus

Claims (3)

A wind farm that uses wind energy to generate electricity,
A plurality of wind turbine generators having wind turbine blades and mounted with a variable speed generator and a controllable power converter;
A plurality of anemometers that are respectively attached to the plurality of wind turbine generators and measure wind speed;
A plurality of individual control devices that respectively control the plurality of wind power generators and acquire and store operation information representing the operation state of these wind power generators, and
After controlling the whole wind farm and using the operation information of each wind power generator from the plurality of individual control devices and the virtual energy piece, the generator side torque of the wind power generator is adjusted. A wind farm comprising: a wind farm control device that generates a command value for control and transmits the generated command value to an individual control device of the corresponding wind turbine generator.   In the wind farm control device, a wind power generator having a maximum output increase when a positive virtual energy piece is given and a maximum output increase when a negative virtual energy piece is given by the processing. The wind farm according to claim 1, wherein a generator-side torque control process is performed when a total value of output increases of the two selected wind power generators is larger than a predetermined energy limit. .   The wind farm according to claim 2, wherein the generator side torque control processing is performed through control of the power converter according to a command value generated by the wind farm controller.

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