阅读说明：本技术 一种串列式双风轮风电机组协同控制方法 (Tandem type double-wind-wheel wind turbine generator set cooperative control method ) 是由 郭小江 李新凯 唐巍 叶昭良 闫姝 付明志 秦猛 劳文欣 于 2020-12-22 设计创作，主要内容包括：本发明公开了一种串列式双风轮风电机组协同控制方法,属于风电控制技术领域。针对目前串列式双风轮机组在运行上未能解耦,运行效率偏低的问题,提出一种具有传动解耦的串列双风轮风电机组前后风轮协同控制策略,首先通过划分前后风轮的运行区间并确定最优出力值后,以风电机组整体出力最大为目标,通过调节前后风轮的转速及桨距角,进行前后风轮的出力协同控制。本发明以机组整机效率最高、载荷最低为控制目标,前后两风轮协同配合,使机组效率更高,高效区更宽,并网更加友好,可大幅度降低风电机组度电成本,提高机组并网特性。(The invention discloses a tandem type double-wind-wheel wind turbine generator set cooperative control method, and belongs to the technical field of wind power control. Aiming at the problems that the existing tandem type double-wind-wheel wind turbine set cannot be decoupled in operation and is low in operation efficiency, a cooperative control strategy of front and rear wind wheels of the tandem type double-wind-wheel wind turbine set with transmission decoupling is provided. The invention takes the highest efficiency and the lowest load of the whole machine of the unit as control targets, and the front wind wheel and the rear wind wheel are cooperatively matched, so that the efficiency of the unit is higher, the high-efficiency area is wider, the grid connection is more friendly, the power consumption cost of the wind turbine can be greatly reduced, and the grid connection characteristic of the unit is improved.)

1. A tandem type double-wind-wheel wind turbine generator set cooperative control method is characterized in that after the operation intervals of front and rear wind wheels are divided and an optimal output value is determined, the output of the front and rear wind wheels is cooperatively controlled by adjusting the rotating speed and the pitch angle of the front and rear wind wheels with the maximum overall output of the wind turbine generator as a target.

2. The tandem double-wind-wheel wind turbine generator set cooperative control method according to claim 1, wherein when the pitch angles of the front wind wheel and the rear wind wheel are adjusted, the pitch angle of the front wind wheel blade is obtained by a sensor feedback signal of a pitch system of the front wind wheel, and the pitch angle of the rear wind wheel blade is obtained by a sensor feedback signal of a pitch system of the rear wind wheel.

3. The tandem dual-rotor wind turbine generator set cooperative control method according to claim 1, wherein when the rotation speeds of the front rotor and the rear rotor are adjusted, the rotation speed of the front rotor is obtained from a rotor rotation speed feedback signal of the dual-rotor generator, and the rotation speed of the rear rotor is obtained from a rotor feedback signal of the dual-rotor generator.

4. The tandem type double-wind-wheel wind turbine generator set cooperative control method according to claim 3, characterized in that according to an optimal tip speed ratio designed by a front wind wheel, optimal rotating speeds corresponding to different wind speeds before a rated wind speed are determined, optimal pitch angles corresponding to different wind speeds after the rated wind speed are determined, and a cut-out wind speed of the front wind wheel is determined according to a blade limit load; and designing an optimal tip speed ratio according to the rear wind wheel, determining the optimal rotating speed corresponding to different wind speeds before the rated wind speed of the rear wind wheel, determining the optimal pitch angle corresponding to different wind speeds after the rated wind speed, and determining the cut-out wind speed of the rear wind wheel according to the blade limit load.

5. The method of claim 1, wherein the current of the inverter is adjusted to adjust the rotational speed of each of the front and rear wind wheels, and the power of the dual wind wheels is adjusted to maximize the total output of the tandem dual wind wheel wind turbine.

6. The tandem type double-wind-wheel wind turbine generator set cooperative control method according to claim 1, wherein the operation interval of the front and rear wind wheels is divided according to the wind speed sections corresponding to the high-efficiency areas of the front and rear wind wheels, and the operation interval of the front and rear wind wheels is divided with the aim of the widest high-efficiency area of the generator set.

7. The tandem double-wind-wheel wind power generation unit cooperative control method according to claim 6, wherein when the operation zone is divided, the start-up wind speed, the rated wind speed and the stop-up wind speed of the rear wind wheel are higher than those of the front wind wheel.

8. The method for cooperatively controlling the tandem double-wind-wheel wind turbine generator set according to claim 1, wherein the output cooperation is achieved by changing the rotation speed and the pitch angle of the front and rear wind wheels to achieve the control targets of highest power and lowest load.

9. The tandem double-wind-wheel wind turbine generator set cooperative control method according to claim 1, characterized in that when an extreme wind condition or a shutdown wind speed is met, a reverse braking torque is provided for the front wind wheel by controlling the rear wind wheel; when the voltage of the power grid drops, the rear wind wheel continues to operate by coordinating the voltages of the two wind wheels.

10. The tandem double-wind-wheel wind turbine generator set cooperative control method according to claim 1, wherein a front wind wheel power curve is designed according to a conventional single wind turbine generator set, and a rear wind wheel power curve has redundancy.

Technical Field

The invention belongs to the technical field of wind power control, and particularly relates to a tandem type double-wind-wheel wind power generator set cooperative control method.

Background

With the rapid development of installed capacity of wind power, the current mainstream wind turbine generator adopts a single-wind-wheel horizontal shaft form and develops towards large scale, but with the large scale development of the wind turbine generator, the core key technology of the wind turbine generator is limited, and the development of a new-form efficient wind energy conversion device is urgently needed.

The tandem double wind wheel structure is emphasized by its high efficiency and mature key core equipment. However, the prior reported double-wind turbine set adopts two wind wheels which are coaxial or connected to the main shaft through a bevel gear. In the structural form, the two wind wheels only can rotate at the same speed, and the independent operation of the rotating speeds of the two wind wheels and the cooperative control of the front wind wheel and the rear wind wheel can not be realized, so that the two wind wheels can not operate in respective high-efficiency areas, and the overall efficiency of the unit is low.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a cooperative control method for a tandem type dual wind turbine generator set, which can improve the wind energy utilization rate and reduce the power consumption cost of the wind turbine generator set.

The invention is realized by the following technical scheme:

a tandem type double-wind-wheel wind turbine generator set cooperative control method is characterized in that after operation intervals of front and rear wind wheels are divided and an optimal output value is determined, the output of the front and rear wind wheels is cooperatively controlled by adjusting the rotating speed and the pitch angle of the front and rear wind wheels with the maximum total output of the wind turbine generator as a target.

Preferably, when the pitch angles of the front wind wheel and the rear wind wheel are adjusted, the pitch angle of the front wind wheel blade is obtained by a feedback signal of a pitch system sensor of the front wind wheel, and the pitch angle of the rear wind wheel blade is obtained by a feedback signal of a pitch system sensor of the rear wind wheel.

Preferably, when the rotating speeds of the front wind wheel and the rear wind wheel are adjusted, the rotating speed of the front wind wheel is obtained by a rotating speed feedback signal of an outer rotor of the double-rotor generator, and the rotating speed of the rear wind wheel is obtained by a rotating speed feedback signal of an inner rotor of the double-rotor generator.

Further preferably, the optimal tip speed ratio is designed according to the front wind wheel, the optimal rotating speed corresponding to different wind speeds before the rated wind speed is determined, the optimal pitch angle corresponding to different wind speeds after the rated wind speed is determined, and the cut-out wind speed of the front wind wheel is determined according to the blade limit load; and designing an optimal tip speed ratio according to the rear wind wheel, determining the optimal rotating speed corresponding to different wind speeds before the rated wind speed of the rear wind wheel, determining the optimal pitch angle corresponding to different wind speeds after the rated wind speed, and determining the cut-out wind speed of the rear wind wheel according to the blade limit load.

Preferably, the respective rotating speeds of the front wind wheel and the rear wind wheel are adjusted by adjusting the current of the converter, and then the overall output of the tandem type double-wind-wheel wind turbine generator set is maximized by adjusting the power of the double wind wheels.

Preferably, the operation intervals of the front wind wheel and the rear wind wheel are divided according to the wind speed sections corresponding to the high-efficiency areas of the front wind wheel and the rear wind wheel, and the operation intervals of the front wind wheel and the rear wind wheel are divided by taking the widest high-efficiency area of the unit as a target.

Further preferably, when the operation area is divided, the starting wind speed, the rated wind speed and the stopping wind speed of the rear wind wheel are higher than those of the front wind wheel.

Preferably, the output cooperation is realized by changing the rotating speed and the pitch angle of the front wind wheel and the rear wind wheel, so that the control targets of highest power and lowest load are achieved.

Preferably, when an extreme wind condition or a shutdown wind speed is met, a reverse braking torque is provided for the front wind wheel by controlling the rear wind wheel; when the voltage of the power grid drops, the rear wind wheel continues to operate by coordinating the voltages of the two wind wheels.

Preferably, the front wind wheel power curve is designed according to a conventional single wind turbine set, and the rear wind wheel power curve has redundancy.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention discloses a tandem double-wind-wheel wind turbine generator set cooperative control method, which aims at solving the problems that the prior tandem double-wind-wheel wind turbine generator set cannot be decoupled in operation and has low operation efficiency. The invention realizes decoupling from the transmission of the wind generating set, thereby realizing the independent control of the front wind wheel and the rear wind wheel, and essentially providing possibility for cooperative control; the invention takes the highest efficiency and the lowest load of the whole machine of the unit as control targets, and the front wind wheel and the rear wind wheel are cooperatively matched, so that the efficiency of the unit is higher, the high-efficiency area is wider, the grid connection is more friendly, the power consumption cost of the wind turbine can be greatly reduced, and the grid connection characteristic of the unit is improved.

Further, since the fluid bypasses the front wind wheel, the wind energy is absorbed by the front wind wheel, and the fluid flowing into the rear wind wheel is reduced in speed, relative to the incoming wind speed, the operation interval difference exists between the front wind wheel and the rear wind wheel. The front wind wheel operation interval is designed according to a conventional wind turbine generator, the starting wind speed of the rear wind wheel is higher, the corresponding rated wind speed is higher, and the stopping wind speed is also higher.

Furthermore, when extreme wind conditions or shutdown wind speeds are met, the two wind wheels coordinate the control level to provide reverse braking torque for the front wind wheel by controlling the rear wind wheel, and the load of the unit is minimized by a cooperative load reduction strategy, so that the safety of the unit is ensured. When the voltage of the power grid drops, the rear wind wheels continue to operate by coordinating the voltages of the two wind wheels, the voltage level of the generator is maintained, and the adjustability of the network source of the double wind turbines is improved.

Furthermore, the power curve of the front wind wheel is designed according to a conventional single wind turbine set, the power curve of the rear wind wheel has redundancy, and the double wind turbine set can finally generate higher power before rated power by cooperatively controlling the output of the two wind wheels, so that the double wind turbine set can adapt to a wider wind speed section.

Drawings

FIG. 1 is a logic diagram of the coordinated control method of the tandem type double-wind-wheel wind turbine generator set of the present invention;

FIG. 2 is a schematic diagram of the optimal operation interval division of the front and rear wind wheels of the present invention;

FIG. 3 is a schematic diagram of the power generated by front and rear wind turbines of the present invention.

Detailed Description

The invention will now be described in further detail with reference to the drawings and specific examples, which are given by way of illustration and not by way of limitation.

The logic diagram of the coordinated control method of the tandem type double-wind-wheel wind generating set is shown in figure 1, and the control strategy of the double-wind-wheel wind generating set system comprises the following steps: the operating interval of the double wind wheels and the collaborative output of the front and rear wind wheels are optimal; setting the optimal output of the front wind wheel and the optimal output of the rear wind wheel; and the front wind wheel is controlled by variable speed and variable pitch, and the rear wind wheel is controlled by variable speed and variable pitch.

The pitch angle of the front wind wheel blade is obtained by a feedback signal of a front wind wheel variable pitch system sensor, and the pitch angle of the rear wind wheel blade is obtained by a feedback signal of a rear wind wheel variable pitch system sensor. The rotating speed of the front wind wheel is obtained by a rotating speed feedback signal of an outer rotor of the double-rotor generator, and the rotating speed of the rear wind wheel is obtained by a feedback signal of an inner rotor of the double-rotor generator. The respective rotating speeds of the double wind wheels are adjusted by adjusting the current of the converter, so that the purpose of controlling the power of the double wind wheels is achieved.

The output of the front wind wheel is adjusted by adjusting the rotating speed and the pitch angle of the front wind wheel. And adjusting the rotating speed and the pitch angle of the wind wheel after adjusting, and adjusting the output of the wind wheel after adjusting. The rotating speed and the pitch angle of the front wind wheel and the rear wind wheel are adjusted, so that the total output force of the unit is maximum, the load is minimum, and the unit is not limited to the maximum output force of one wind wheel of the front wind wheel or the rear wind wheel. Further, the overall high-efficiency area of the unit is wider by dividing the optimal operation interval of the rear wind wheel. The power curve of the front wind wheel is designed according to a conventional single wind wheel set, the rear wind wheel adopts a certain redundancy design, and the power generation amount of the double wind wheel set is higher before rated power by cooperatively controlling the output of the two wind wheels, so that the double wind wheel set can adapt to a wider wind speed section.

Designing an optimal tip speed ratio according to a front wind wheel, determining optimal rotating speeds corresponding to different wind speeds before a rated wind speed, determining optimal pitch angles corresponding to different wind speeds after the rated wind speed, and determining the cut-out wind speed of the front wind wheel according to the blade limit load; and designing an optimal tip speed ratio according to the rear wind wheel, determining the optimal rotating speed corresponding to different wind speeds before the rated wind speed of the rear wind wheel, determining the optimal pitch angle corresponding to different wind speeds after the rated wind speed, and determining the cut-out wind speed of the rear wind wheel according to the blade limit load.

As shown in FIG. 2, the starting wind speed of the front wind wheel is V_1minRated wind speed of V_1NOptimum wind wheel C_p1maxThe operation interval is V_1minAnd V_1NV of_1maxThe wind speed is cut out for the wind wheel and is determined by the limit load of the unit.

After the airflow flows through the front wind wheel, the fluid speed of the airflow entering the rear wind wheel is reduced, so that the inflow speed of the rear wind wheel is lower than that of the front wind wheel, and the starting wind speed of the rear wind wheel is V_2minRated wind speed of V_2NOptimum wind wheel C_p2maxThe operation interval is V_2minAnd V_2NAnd the starting wind speed and the rated wind speed of the rear wind wheel are both higher than those of the front wind wheel.

The high-efficiency area of the double-wind turbine set is wider than that of a single-wind turbine set with the same capacity.

As shown in fig. 3, the rear wind wheel adopts a certain redundancy design, the wind speed corresponding to the rated power of the rear wind wheel is higher, and by adopting the control strategy, the wind speed corresponding to the rated power of the double-wind-wheel unit is higher, and the unit can keep a high-efficiency area in a wider wind speed section.

When extreme wind conditions or shutdown wind speed are met, the two wind wheels coordinate the control level to provide reverse braking torque for the front wind wheel by controlling the rear wind wheel, and the load of the unit is minimized by a cooperative load reduction strategy, so that the safety of the unit is ensured. When the voltage of the power grid drops, the rear wind wheels continue to operate by coordinating the voltages of the two wind wheels, the voltage level of the generator is maintained, and the adjustability of the network source of the double wind turbines is improved.

It should be noted that the above description is only a part of the embodiments of the present invention, and equivalent changes made to the system described in the present invention are included in the protection scope of the present invention. Persons skilled in the art to which this invention pertains may substitute similar alternatives for the specific embodiments described, all without departing from the scope of the invention as defined by the claims.