WO2022134639A1

WO2022134639A1 - Method for conjunctively controlling wind turbine generator having tandem double-rotors

Info

Publication number: WO2022134639A1
Application number: PCT/CN2021/114941
Authority: WO
Inventors: 郭小江; 李新凯; 唐巍; 叶昭良; 闫姝; 秦猛; 劳文欣; 付明志
Original assignee: 中国华能集团清洁能源技术研究院有限公司; 华能海上风电科学技术研究有限公司
Priority date: 2020-12-22
Filing date: 2021-08-27
Publication date: 2022-06-30
Also published as: CN112648141A; CN112648141B

Abstract

A method for conjunctively controlling a wind turbine generator having tandem double-rotors, comprising: first dividing operating sections of front and rear rotors and determining the optimal output power values; and then conjunctively controlling output power of the front and rear rotors by adjusting rotation speeds and pitch angles of the front and rear rotors, in order to maximize the output power of the whole wind turbine generator. In order to maximize the overall efficiency of the generator and minimize the load of the generator, the front and rear rotors work in conjunction with each other, so that the generator has higher efficiency, a wider high-efficiency section, and more friendly grid-connection, greatly reducing the levelized cost of electricity of the wind turbine generator, and improving the grid-connection characteristics of the generator.

Description

A collaborative control method for tandem double-wind turbine wind turbines

This application claims the priority of the Chinese patent application with the application number 202011529919.1 and the invention titled "A Synergistic Control Method for Tandem Double Wind Turbine Wind Turbines" filed with the China Patent Office on December 22, 2020, the entire contents of which are passed Reference is incorporated in this application.

technical field

The invention belongs to the technical field of wind power control, and in particular relates to a coordinated control method for a tandem double-wind turbine wind generator set.

Background technique

With the rapid development of wind power installed capacity, the current mainstream wind turbines adopt the single-rotor horizontal axis form, and they are developing towards large-scale. High-efficiency wind energy conversion device.

The tandem double wind turbine structure is valued for its high efficiency and mature key core equipment. However, existing dual wind turbine units use two wind turbines coaxially or connected to the main shaft through bevel gears. The two wind rotors in the structure can only rotate at the same speed, and cannot realize the independent operation of the rotational speed and the coordinated control of the front and rear wind rotors, so that the two wind rotors cannot operate in their respective high-efficiency areas, resulting in a low overall efficiency of the unit. .

SUMMARY OF THE INVENTION

In order to solve the above problems, the purpose of the present invention is to provide a coordinated control method for a tandem double-wind turbine wind turbine, which can improve the utilization rate of wind energy and reduce the cost per kilowatt-hour of the wind turbine.

The present invention is achieved through the following technical solutions:

A collaborative control method for a tandem double-wind turbine wind turbine. After dividing the operating interval of the front and rear wind turbines and determining the optimal output value, the overall output of the wind turbine is taken as the goal. The output of the front and rear wind rotors is controlled cooperatively.

Preferably, when adjusting the pitch angles of the front wind rotor and the rear wind rotor, the blade pitch angle of the front wind rotor is obtained from the feedback signal of the front wind rotor pitch system sensor, and the rear wind rotor blade pitch angle is obtained by the rear wind rotor pitch system. The sensor feedback signal is obtained.

Preferably, when adjusting the rotational speed of the front wind rotor and the rear wind rotor, the rotational speed of the front wind rotor is obtained from the feedback signal of the outer rotor speed of the dual rotor generator, and the rotational speed of the rear wind rotor is obtained from the feedback signal of the inner rotor of the dual rotor generator.

Further preferably, according to the best tip speed ratio of the front wind rotor design, determine the best rotation speed corresponding to different wind speeds before the rated wind speed, determine the best pitch angle corresponding to different wind speeds after the rated wind speed, and determine the front wind rotor according to the blade limit load. Outlet wind speed: According to the optimal tip speed ratio of the rear rotor design, determine the optimal rotation speed corresponding to different wind speeds before the rated wind speed of the rear rotor, determine the optimal pitch angle corresponding to different wind speeds after the rated wind speed, and determine the rear wind according to the ultimate load of the blade. Wheel cut out wind speed.

Preferably, the respective rotational speeds of the front wind rotor and the rear wind rotor are adjusted by adjusting the current of the converter, and then the overall output of the tandem double wind turbine wind turbine can be maximized by adjusting the power of the double wind turbines.

Preferably, dividing the operating interval of the front and rear wind rotors is to divide the operating intervals of the front and rear wind rotors according to the wind speed sections corresponding to the high-efficiency areas of the front and rear wind rotors, with the goal of the widest high-efficiency area of the unit.

Further preferably, when the operating interval is divided, the starting wind speed, rated wind speed and shutdown wind speed of the rear wind rotor are higher than those of the front wind rotor.

Preferably, the output synergy is achieved by changing the rotational speed and pitch angle of the front and rear wind rotors to achieve the control objectives of the highest power and the lowest load.

Preferably, when extreme wind conditions or shutdown wind speed is encountered, the rear wind wheel is controlled to provide a reverse braking torque for the front wind wheel; when the voltage of the grid drops, the voltage of the two wind wheels is coordinated to make the rear wind wheel continue to continue. run.

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

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

The cooperative control method for a tandem double-wind turbine wind turbine disclosed in the present invention aims at the problem that the current tandem double-wind turbine cannot be decoupled in operation and the operation efficiency is low, and proposes a tandem with transmission decoupling. The cooperative control strategy of the front and rear wind turbines of the double-wind turbine wind turbine, after dividing the operating interval of the front and rear wind turbines and determining the optimal output value, the goal is to maximize the overall output of the wind turbine, rather than the output of a certain wind turbine. The rotational speed and pitch angle of the front and rear wind rotors are used to coordinate the output of the front and rear wind rotors. The invention realizes decoupling from the drive of the wind generator set, so that the independent control of the front and rear wind rotors can be realized, thereby providing the possibility for cooperative control in essence; The cooperation of the front and rear wind turbines makes the unit more efficient, the high-efficiency area is wider, and the grid connection is more friendly, which can greatly reduce the kWh cost of the wind turbine and improve the grid connection characteristics of the unit.

Further, since the wind energy is absorbed by the front wind rotor after the fluid bypasses the front wind rotor, and the fluid velocity of the fluid flowing into the rear wind rotor is reduced, there is an operating interval difference between the front wind rotor and the rear wind rotor relative to the incoming wind speed. The operating range of the front wind rotor is designed according to the conventional wind turbine, and the rear wind rotor has a higher starting wind speed, and the corresponding rated wind speed is higher, and the shutdown wind speed is also higher.

Further, when encountering extreme wind conditions or shutdown wind speed, the two wind turbine coordination control stages provide reverse braking torque for the front wind rotor by controlling the rear wind rotor, and through the coordinated load reduction strategy, the unit load is minimized and the unit load is guaranteed. Safety. When the voltage of the power grid drops, by coordinating the voltages of the two wind turbines, the rear wind turbine continues to operate, maintains the voltage level of the generator, and increases the network source adjustability of the double wind turbine unit.

Further, the power curve of the front wind turbine is designed according to the conventional single wind turbine unit, and the power curve of the rear wind turbine has redundancy, which can control the output of the two wind turbines through coordination, and finally make the double wind turbine unit generate higher power before the rated power. , which can adapt to a wider wind speed segment.

Description of drawings

Fig. 1 is the logic diagram of the cooperative control method of the tandem double-wind turbine wind turbine of the present invention;

Fig. 2 is the 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 generation of the front and rear wind turbines of the present invention.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The logic diagram of the cooperative control method of the tandem dual-wind turbine wind turbine of the present invention is shown in Figure 1. The system control strategy of the dual-wind turbine wind turbine includes: the operation interval of the dual-wind turbine and the optimal coordinated output of the front and rear wind turbines; the optimal front wind turbine Output setting, the output of the rear wind rotor is optimally set; the front wind rotor is controlled by variable speed and pitch, and the rear wind rotor is controlled by variable speed and pitch.

The pitch angle of the front wind rotor blade is obtained from the feedback signal of the front wind rotor pitch system sensor, and the rear wind rotor blade pitch angle is obtained from the sensor feedback signal of the rear wind rotor pitch system. The rotational speed of the front rotor is obtained from the feedback signal of the outer rotor of the dual-rotor generator, and the rotational speed of the rear rotor is obtained from the feedback signal of the inner rotor of the dual-rotor generator. By adjusting the current of the converter, the respective rotational speeds of the double wind wheels are adjusted to achieve the purpose of controlling the power of the double wind wheels.

Adjust the output of the front wind wheel by adjusting the rotational speed and pitch angle of the front wind wheel. Adjust the speed and pitch angle of the rear rotor, and adjust the output of the rear rotor. By adjusting the rotational speed and pitch angle of the front and rear rotors, the overall output of the unit is maximized and the load is minimized, rather than being limited to the front or rear rotor with the largest output. Further, by dividing the optimal operation interval of the rear wind turbine, it is obtained that the overall high efficiency area of the unit is wider. The power curve of the front wind turbine is designed according to the conventional single wind turbine unit, and the rear wind turbine adopts a certain redundancy design. wider wind speed segment.

According to the optimal tip speed ratio of the front wind rotor design, determine the optimal rotation speed corresponding to different wind speeds before the rated wind speed, determine the optimal pitch angle corresponding to different wind speeds after the rated wind speed, and determine the cut-out wind speed of the front wind rotor according to the limit load of the blade; Design the optimal tip speed ratio of the rear rotor, determine the optimal rotation speed corresponding to different wind speeds before the rated wind speed of the rear rotor, determine the optimal pitch angle corresponding to different wind speeds after the rated wind speed, and determine the cut-out wind speed of the rear rotor according to the limit load of the blade .

As shown in Figure 2, the starting wind speed of the front wind rotor is V1min, the rated wind speed is V1N, the optimal Cp1max operating range of the wind rotor is between V1min and V1N, and V1max is the wind speed of the wind rotor, which is determined by the limit load of the unit.

After the airflow flows through the front rotor, the fluid velocity of the rear rotor will decrease, so the inflow velocity of the rear rotor is lower than the inflow velocity of the front rotor. The starting wind speed of the rear rotor is V2min, the rated wind speed is V2N, and the best Cp2max operation of the wind rotor. The interval is between V2min and V2N, and the starting wind speed and rated wind speed of the rear wind rotor are higher than those of the front wind rotor.

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

As shown in Figure 3, the rear wind turbine adopts a certain redundancy design, and its rated power corresponds to a higher wind speed. Using this control strategy, the rated power of the dual-wind turbine unit corresponds to a higher wind speed, and the unit can operate in a wider wind speed section. Maintain a high efficiency zone.

When encountering extreme wind conditions or shutdown wind speed, the two wind rotor coordination control stages provide reverse braking torque for the front wind rotor by controlling the rear wind rotor, and through the coordinated load reduction strategy, the unit load is minimized and the unit safety is ensured. When the voltage of the power grid drops, by coordinating the voltages of the two wind turbines, the rear wind turbine continues to operate, maintains the voltage level of the generator, and increases the network source adjustability of the double wind turbine unit.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as It is the protection scope of the present invention.

Claims

A tandem dual-wind-wheel wind turbine cooperative control method is characterized in that, after dividing the operating interval of the front and rear wind turbines and determining the optimal output value, the overall output of the wind turbine is taken as the goal, and by adjusting the rotational speed of the front and rear wind turbines and The pitch angle is used to coordinate the output of the front and rear rotors.
The coordinated control method for a tandem double-wind turbine wind turbine according to claim 1, wherein when adjusting the pitch angles of the front wind rotor and the rear wind rotor, the pitch angle of the front wind rotor is changed by the pitch angle of the front wind rotor. The feedback signal of the system sensor is obtained, and the pitch angle of the rear rotor blade is obtained from the feedback signal of the rear rotor pitch system sensor.
The method for coordinated control of a tandem double-wind turbine wind turbine according to claim 1, wherein when adjusting the rotational speeds of the front wind rotor and the rear wind rotor, the rotational speed of the front wind rotor is obtained from the feedback signal of the rotational speed of the outer rotor of the dual-rotor generator. , the speed of the rear rotor is obtained from the feedback signal of the inner rotor of the dual-rotor generator.
The collaborative control method for a tandem double-wind turbine wind turbine as claimed in claim 3, wherein, according to the optimal tip speed ratio of the front wind rotor design, the optimal rotational speed corresponding to different wind speeds before the rated wind speed is determined, and after the rated wind speed is determined For the optimal pitch angle corresponding to different wind speeds, the cut-out wind speed of the front wind rotor is determined according to the ultimate load of the blade; according to the optimal tip speed ratio of the design of the rear wind rotor, the optimal speed corresponding to different wind speeds before the rated wind speed of the rear wind rotor is determined, and the rated wind speed is determined. After the wind speed, the optimal pitch angle corresponding to different wind speeds is determined according to the ultimate load of the blade.
The coordinated control method for a tandem double-wind turbine wind turbine according to claim 1, wherein the respective rotational speeds of the front and rear wind-rotors are adjusted by adjusting the current of the converter, and then the respective rotational speeds of the front-wind-wheel and the rear-wind-wheel are adjusted by adjusting the current of the converter. Adjustment to maximize the overall output of the tandem double-wind turbine wind turbine.
The method for collaborative control of a tandem double-wind turbine wind turbine according to claim 1, wherein the operation range of the front and rear wind turbines is divided according to the wind speed sections corresponding to the high-efficiency areas of the front and rear wind turbines, and the widest high-efficiency area of the unit is The goal is to divide the operating range of the front and rear wind rotors.
The collaborative control method for a tandem double-wind turbine wind turbine according to claim 6, wherein when the operating interval is divided, the starting wind speed, rated wind speed and shutdown wind speed of the rear wind turbine are higher than those of the front wind turbine.
The coordinated control method for a tandem double-wind turbine wind turbine according to claim 1, wherein the output coordination is achieved by changing the rotational speed and pitch angle of the front and rear wind turbines to achieve the highest power and lowest load control goals.
The coordinated control method for a tandem double-wind turbine wind turbine according to claim 1, wherein when extreme wind conditions or shutdown wind speeds are encountered, the rear wind rotor is controlled to provide a reverse braking torque for the front wind rotor; When the grid voltage drops, by coordinating the voltages of the two wind turbines, the rear wind turbine can continue to run.
The coordinated control method for a tandem double-wind turbine wind turbine set according to claim 1, wherein the power curve of the front wind turbine is designed according to a conventional single wind turbine set, and the power curve of the rear wind turbine has redundancy.