Braking method of vertical axis wind turbine

Abstract

The invention discloses a braking method of a vertical-axis wind turbine and belongs to the technical field of wind turbines. A controller, a detection component, a star sealing contactor and an electromagnetic plunger brake are installed in the vertical-axis wind turbine. The braking method for the generator under the fault condition comprises the following steps that S1, the vertical-axis wind turbine generates power normally; s2) the controller finds a fault; (S3) star sealing is started, and star sealing is conducted for t s; s4) controlling to cancel star sealing, and detecting the rotating speed; s5) judging whether the rotating speed is reduced to be within the action rotating speed range of the electromagnetic plunger brake, and if the rotating speed is reduced to be within the action rotating speed range of the electromagnetic plunger brake, executing the step S6); the method has the advantages that the mode that the star sealing speed reduction technology and the electromagnetic braking technology are combined is adopted, stable speed reduction and reliable braking of the vertical axis wind turbine are effectively achieved, and the power generation state is automatically recovered after faults are eliminated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vertical axis wind turbine, and particularly relates to a braking method of vertical axis wind turbine. BACKGROUND

[0002] The wind turbine is a kind of power generation device that converts the kinetic energy of wind into mechanical kinetic energy, and then converts the mechanical kinetic energy into electric kinetic energy. The energy used has the advantages of being clean, flexible, renewable and inexhaustible, and is one of the ideal energy sources for human beings, which is of great benefit to environmental protection. The main types of wind turbine include horizontal axis wind turbine and vertical axis wind turbine. The horizontal axis wind turbine needs to be operated to face the wind when the wind direction changes, so as to maximize the capture of wind energy. In strong wind, the windward area is reduced to reduce the speed and protect the equipment safety. The structure is relatively complex. The vertical axis wind turbine does not need to be operated to face the wind when the wind direction changes, and can capture wind energy from all directions. The structure is more simplified. However, the vertical axis wind turbine usually adopts electromagnetic friction brake to brake the wind wheel in strong wind or fault, so that the wind wheel slows down until it stops. However, when the high-speed rotating wind wheel is braked by this braking method, the braking energy is positively related to the square of the speed. The higher the speed, the greater the braking energy. The mechanical structure such as brake and blade link will bear a huge impact. In addition, the friction brake will generate a large amount of heat, which is easy to cause damage to the friction disc, failure of the mechanical structure of the brake, and the electromagnetic friction brake needs to generate an electromagnetic suction force equivalent to the braking torque when releasing the wind wheel, which consumes a large amount of electricity. In addition, the current market control method cannot realize the mechanism of automatically judging the release of the braking state according to the current wind speed. Only manual operation release or relying on the pre-set braking time is supported to release the wind wheel after the time is up.

[0003] In view of the above-mentioned braking method of vertical axis wind turbine, the later vertical axis wind turbine uses permanent magnet generator, and installs a star contactor in the generator circuit. When a fault occurs, the generator control stator winding is short-circuited to generate a star torque that hinders the rotation of the wind wheel, so as to slow down the wind wheel. However, this braking method cannot reduce the speed of the wind wheel to zero, so a corresponding redundant structure needs to be designed to achieve this purpose.

[0004] In view of the above-mentioned existing technology, it is necessary to reasonably improve the braking method of the existing vertical axis wind turbine. For this purpose, the applicant has made a beneficial design, and the technical scheme to be introduced below is produced in this background. SUMMARY

[0005] The objective of this invention is to provide a braking method for a vertical axis wind turbine. By combining star-shaped deceleration technology with electromagnetic braking technology, it effectively achieves smooth deceleration and reliable braking of the wind turbine rotor. It can also monitor and promptly detect whether the generator is out of its operating range, and automatically resume power generation when it returns to normal. The method is timely and precise in its control.

[0006] The objective of this invention is achieved by providing a braking method for a vertical axis wind turbine, wherein the vertical axis wind turbine is equipped with a controller, a detection component, a sealing contactor, and an electromagnetic plunger brake. The controller controls the operation of the vertical axis wind turbine, and its braking method for the generator in fault conditions includes the following steps: S1) The vertical axis wind turbine is generating electricity normally; S2) A fault was detected in the controller; S3) The controller starts the star-sealing contactor, enters the star-sealing braking state, and maintains it for t seconds; S4) The controller releases the star brake and monitors the current speed of the vertical axis wind turbine in real time; S5) The controller determines whether the speed has dropped to within the operating speed range of the electromagnetic plunger brake. If the speed has dropped to within the operating speed range of the electromagnetic plunger brake, then proceed to step S6); if the speed has not dropped to within the operating speed range of the electromagnetic plunger brake, then continue to proceed to step S3). S6) The electromagnetic plunger brake is activated, braking the impeller.

[0007] In a specific embodiment of the present invention, the faults include excessive rotational speed, excessive wind speed, and excessive current.

[0008] In another specific embodiment of the present invention, after the electromagnetic plunger brake brakes the wind turbine, when the fault is detected to be eliminated, the controller disconnects the sealing contactor, starts the electromagnetic plunger brake, releases the brake on the wind turbine, and restores normal power generation.

[0009] In another specific embodiment of the present invention, when the fault is specifically excessive wind speed, the following steps are included: S1) The vertical axis wind turbine is generating electricity normally; S2) A fault was detected in the controller; S3) The controller starts the star-sealing contactor, enters the star-sealing braking state, and continues for t seconds; S4) The controller releases the star brake and monitors the current speed of the vertical axis wind turbine in real time; S5) The controller determines whether the speed has dropped to within the operating speed range of the electromagnetic plunger brake. If the speed has dropped to within the operating speed range of the electromagnetic plunger brake, then proceed to step S6); if the speed has not dropped to within the operating speed range of the electromagnetic plunger brake, then continue to proceed to step S3). S6) The electromagnetic plunger brake is activated, braking the wind turbine and initiating and continuously sealing the star brake. S7) After the star-sealing braking state lasts for t seconds, the external wind speed is detected; S8) The controller determines whether the external wind speed is within the working wind speed range. If the external wind speed is within the working wind speed range, then proceed to step S9); if the external wind speed is not within the working wind speed range, then continue to proceed to step S7). S9) Disconnect the sealing contactor, activate the electromagnetic plunger brake, release the brake on the wind turbine, and restore normal power generation.

[0010] The present invention, due to the aforementioned structure, has the following beneficial effects: First, the vertical axis wind turbine can promptly detect when the generator exceeds its operating range, and then uses intermittent star-shaped braking to reduce the rotor speed until the rotor speed drops to within the operating range of the electromagnetic plunger brake. The electromagnetic plunger brake is then activated to stop the rotor, effectively achieving precise control and reliable braking of the vertical axis wind turbine rotor speed. Second, the electromagnetic plunger brake consumes less power than a friction brake. Third, it automatically detects internal and external operating conditions. When operating conditions exceed a specified threshold, power generation stops; when operating conditions are within the operating range, power generation automatically resumes. The entire wind power generation system can automatically adjust its operating state according to environmental changes, resulting in high control precision and response efficiency. Attached Figure Description

[0011] Figure 1 This is a structural block diagram of the vertical axis wind turbine generator described in this invention; Figure 2 This is a flowchart of the sealing and braking process for the vertical axis wind turbine described in this invention; Figure 3 This is a flowchart illustrating the restart process of the vertical axis wind turbine generator after braking, as described in this invention. Detailed Implementation

[0012] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the applicant's description of the embodiments is not a limitation on the technical solution. Any formal but not substantive changes made based on the concept of the present invention should be considered within the scope of protection of the present invention.

[0013] In the following description, all directional or orientational concepts involving up, down, left, right, front, and back are based on the positions shown in the corresponding figures, and therefore should not be construed as a special limitation on the technical solutions provided by this invention.

[0014] like Figure 1 As shown, this invention relates to a braking method for a vertical axis wind turbine. The vertical axis wind turbine is equipped with a controller, a detection component, a star-connector, and an electromagnetic plunger brake. The detection component can detect wind speed, generator speed, or current, and transmit the detected information to the controller. The controller analyzes the received detection information to determine whether the generator is in a normal operating environment or state. If the generator's operating environment or state is abnormal, a fault signal is generated. The star-connector is a safety device that forms a star-connected closed loop by short-circuiting the generator's three-phase windings, using electromagnetic induction to generate a reverse braking torque, reducing the generator's excessive rotational speed.

[0015] like Figure 2 As shown, the controller controls the operation of the vertical axis wind turbine, and its braking method for the generator in case of a fault includes the following steps: S1) The vertical axis wind turbine is generating electricity normally; S2) A fault was detected in the controller; S3) The controller starts the star-sealing contactor, enters the star-sealing braking state, and maintains it for t seconds; S4) The controller releases the star brake and monitors the current speed of the vertical axis wind turbine in real time; S5) The controller determines whether the speed has dropped to within the operating speed range of the electromagnetic plunger brake. If the speed has dropped to within the operating speed range of the electromagnetic plunger brake, then proceed to step S6); if the speed has not dropped to within the operating speed range of the electromagnetic plunger brake, then continue to proceed to step S3). S6) The electromagnetic plunger brake is activated, braking the impeller.

[0016] In step S2), the controller detects faults based on the detection information provided by the detection component, such as exceeding a set threshold; the faults include abnormal conditions such as excessive rotation speed, excessive wind speed, and excessive current.

[0017] In this technical solution, the use of intermittent star-shaped braking effectively reduces the rotational speed. Especially in steps S3) to S5), after maintaining the star-shaped braking state for t seconds, the braking is canceled, and the rotor speed is detected. If the speed has not dropped to within the range where the electromagnetic plunger brake can operate, the star-shaped braking state is maintained for another t seconds before being canceled, and the rotor speed is detected again. This cycle continues until the rotor speed drops to within the operating speed range of the electromagnetic plunger brake, at which point the rotor is stopped by the electromagnetic plunger brake. This method of using intermittent star-shaped braking to reduce rotor speed allows for precise speed detection, enabling the electromagnetic plunger brake to brake the rotor below the set speed, preventing excessive braking energy and damage to braking components at high speeds. The use of the electromagnetic plunger brake adds redundant braking functionality to the generator, ensuring reliable stopping of the wind turbine and effectively protecting the vertical axis wind turbine.

[0018] like Figure 3 As shown in this embodiment, after the electromagnetic plunger brake brakes the wind turbine, when the fault is detected to be cleared, the controller disconnects the sealing contactor, starts the electromagnetic plunger brake, releases the brake on the wind turbine, and restores normal power generation.

[0019] Furthermore, when the fault is specifically due to excessive wind speed, the braking method for the vertical axis wind turbine includes the following steps: S1) The vertical axis wind turbine is generating electricity normally; S2) A fault was detected in the controller; S3) The controller starts the star-sealing contactor, enters the star-sealing braking state, and continues for t seconds; S4) The controller releases the star brake and monitors the current speed of the vertical axis wind turbine in real time; S5) The controller determines whether the speed has dropped to within the operating speed range of the electromagnetic plunger brake. If the speed has dropped to within the operating speed range of the electromagnetic plunger brake, then proceed to step S6); if the speed has not dropped to within the operating speed range of the electromagnetic plunger brake, then continue to proceed to step S3). S6) The electromagnetic plunger brake is activated, braking the wind turbine and initiating and continuously sealing the star brake. S7) After the star-sealing braking state lasts for t seconds, the external wind speed is detected; S8) The controller determines whether the external wind speed is within the working wind speed range. If the external wind speed is within the working wind speed range, then proceed to step S9); if the external wind speed is not within the working wind speed range, then continue to proceed to step S7). S9) Disconnect the sealing contactor, activate the electromagnetic plunger brake, release the brake on the wind turbine, and restore normal power generation.

[0020] In this invention, the entire wind power generation system can automatically adjust its working status according to changes in the environment, responding promptly and controlling precisely, thus achieving the purpose of the invention.

Claims

1. A braking method for a vertical axis wind turbine, wherein the vertical axis wind turbine is equipped with a controller, a detection component, a sealing contactor, and an electromagnetic plunger brake, the controller controlling the operation of the vertical axis wind turbine, and the braking method for the generator in fault conditions includes the following steps: S1) The vertical axis wind turbine is generating electricity normally; S2) A fault was detected in the controller; S3) The controller starts the star-sealing contactor, enters the star-sealing braking state, and maintains it for t seconds; S4) The controller releases the star brake and monitors the current speed of the vertical axis wind turbine in real time; S5) The controller determines whether the speed has dropped to within the operating speed range of the electromagnetic plunger brake. If the speed has dropped to within the operating speed range of the electromagnetic plunger brake, then proceed to step S6); if the speed has not dropped to within the operating speed range of the electromagnetic plunger brake, then continue to proceed to step S3). S6) The electromagnetic plunger brake is activated, braking the impeller.

2. The braking method for a vertical axis wind turbine according to claim 1, characterized in that: The aforementioned faults include excessive rotation speed, excessive wind speed, and excessive current.

3. The braking method for a vertical axis wind turbine according to claim 1, characterized in that: After the electromagnetic plunger brake brakes the wind turbine, once the fault is detected and cleared, the controller disconnects the sealing contactor, activates the electromagnetic plunger brake, releases the brake on the wind turbine, and restores normal power generation.

4. The braking method for a vertical axis wind turbine according to claim 2, characterized in that: When the fault is specifically due to excessive wind speed, the following steps are included: S1) The vertical axis wind turbine is generating electricity normally; S2) A fault was detected in the controller; S3) The controller starts the star-sealing contactor, enters the star-sealing braking state, and continues for t seconds; S4) The controller releases the star brake and monitors the current speed of the vertical axis wind turbine in real time; S5) The controller determines whether the speed has dropped to within the operating speed range of the electromagnetic plunger brake. If the speed has dropped to within the operating speed range of the electromagnetic plunger brake, then proceed to step S6); if the speed has not dropped to within the operating speed range of the electromagnetic plunger brake, then continue to proceed to step S3). S6) The electromagnetic plunger brake is activated, braking the wind turbine and initiating and continuously sealing the star brake. S7) After the star-sealing braking state lasts for t seconds, the external wind speed is detected; S8) The controller determines whether the external wind speed is within the working wind speed range. If the external wind speed is within the working wind speed range, then proceed to step S9); if the external wind speed is not within the working wind speed range, then continue to proceed to step S7). S9) Disconnect the sealing contactor, activate the electromagnetic plunger brake, release the brake on the wind turbine, and restore normal power generation.

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