Description:Field of Invention
The proposed invention pertains to the development of a hybrid wind turbine that combines horizontal and vertical axis wind turbines for improved and sustainable power generation from renewable energy sources.
The objectives of this invention
The objective of this invention is to develop a hybrid wind turbine that combines horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT) on a single tower which should provide an efficient and space-saving solution for urban wind energy generation.
Background of the Invention
Wind energy conversion devices have existed in the world for a long back. Among those, horizontal axis wind turbine (HAWT) is most widely used for pumping and large power generation which works on medium and high-speed wind. In the other case, a vertical axis wind turbine (VAWT) is used for small power generation which works on low-speed wind from any direction. These HAWT and VAWT are conventional methods used for generating power from renewable wind energy. Instead of making use of the conventional way, hybridization of such wind turbines may be attempted to overcome some issues like intermittent power generation, low wind speed, area-specific usage, and more space utilization.
Description of Prior Art
Research findings on the combining or hybridization of renewable energy sources and wind energy devices have received considerable importance as patents because of their improved and effective power generation. For instance, US20130106193A1 discloses a hybrid Wind-Solar energy device comprising of vertical wind capture turbine assembly which includes a solar energy capture device on the sails or blades surface. Solar-energy capture means flexible or rigid Solar panels mounted on the sails or blade surface. US0090 13053B2 discloses a multi-type wind turbine with a plurality of arms. In that invention, four arms are introduced in the horizontal axis wind turbine, in which each arm includes a main blade and small sub-blades for the effective utilization of wind energy to generate more power from the same swept blade area.
Similarly, for instance, US 20060275105A1 discloses an aerodynamic hybrid vertical axis wind turbine which includes a rotor airfoil and stator blade combination so as to maximize the energy production. WO2022/003395A1 discloses an apparatus for wind, solar, and rain power generation system with water collection. This discloses to the renewable generator that has the ability for adaptability to every weather condition, and usage of processor and sensor for obtaining the effective energy generator. US 2011/025071A1 discloses a hybrid-type vertical shaft turbine for wind power generating devices. This discloses a method of operating a hybrid turbine system having a combination of a Darrieus turbine and a Savonius turbine which is employed to start the system at low speed.
Accordingly, there is an urgent need and demand for a hybrid wind turbine that combines the features of HAWT and VAWT. The present invention overcomes these problems observed in the prior art and discloses herein the operation of a hybrid wind turbine devoid of the above-mentioned drawbacks.
Summary of the Invention
In light of the above-mentioned drawbacks in the prior art, the present invention aims to develop a hybrid wind turbine.
The specific objective of the invention is to design a hybrid wind turbine that combines a horizontal axis wind turbine (HAWT) and three vertical axis wind turbines (VAWT) on a single tower.
A further specific objective of the invention is to provide an efficient and space-saving solution for urban wind energy generation.
Detailed Description of the Invention
The embodiments of the present disclosure provide a novel hybrid wind turbine that combines both horizontal axis wind Turbine (HAWT) and vertical axis wind turbine (VAWT) in a single tower. Two variants are proposed in this work. Variant-1 combines one HAWT and three Savonius S-type VAWT on a single tower. Variant-2 consists of one HAWT with three Tapered Savonius helical type VAWT. In Variant-1, three VAWTs are kept at 120°, at the optimal tower level to reduce the vibration. In Variant-2, three VAWTs are kept in line along the axis of the HAWT tower.
With reference to Figure 1 (Variant-1), the tower height of HAWT is fixed at 4.115m, and the rotor diameter with 3.048m with a capacity to generate 1KW. Also in Variant-1, three Savonius S type VAWTs are kept at a 120° angle having a rotor diameter of 0.65m, blade height of 0.85m, and 1KW (capacity of each VAWT) are fixed at an optimal height of the HAWT tower. The Variant-1 can produce a peak power of 4 KW.
With reference to Figure 2 (Variant-2), the tower height of HAWT is fixed at 4.115m, and the rotor diameter with 3.048m with a capacity to generate 1KW. Also in Variant-2, three Tapered Savonius helical type VAWTs are kept in-line along the axis of the HAWT tower having rotor diameters of 0.35m, 0.5m, and 0.65m; with heights of 0.85m, 0.75m and 0.65m respectively. The three VAWTs' total capacity is about 2.5KW. The Variant-2 can produce a peak power of 3.5 KW.
The automatic stalling and safety systems are proposed in this work to overcome the issues during heavy winds in extreme climate conditions. The automatic stalling of HAWT is operated by a gear drive with a motor mounted below the nacelle which operates at extreme wind conditions through wind speed and direction sensors.
The automatic safety system works during heavy wind which causes the deflection in the HAWT tower. The displacement/force sensors are used to find the variation of deflection in the tower, accordingly, the guy wire(s) will be tightened against the force developed on the tower due to the heavy wind. The tightening of the guy wire provides additional safety to the hybrid wind turbine.
These Hybrid wind turbines address the difficulties that arise during less wind speed (i.e., even below 5m/s wind speed). This innovation addresses the challenges posed by urban landscapes and the limitations of small-scale wind turbine power generation. Seamlessly integrating these two wind turbine types aims to provide an efficient and space-saving solution for urban wind energy generation.
4 Claims & 2 Figures
Brief Description of Drawings
The invention will be described in detail with reference to the exemplary embodiments shown in the figures wherein:
Figure 1 Schematic representation of a hybrid wind turbine (Variant-1)
Figure 2 Schematic representation of a hybrid wind turbine (Variant-2)
Detailed description of the drawing
The embodiments of the present disclosure provide a hybrid wind turbine that combines HAWT and VAWT. The hybrid wind turbine was designed based on the following objectives: i) To generate sustainable power even at lower wind speed without any interruption, ii) To occupy lesser space so as to install in urban areas, iii) To effectively utilize the available renewable energy source, iv) To safeguard the proposed hybrid wind turbine at extreme wind conditions.
With reference to Figure 1, the hybrid wind turbine (Variant-1) is developed in accordance with an embodiment of the present disclosure. In Variant-1, the hybridization is done by combining a three-bladed HAWT (1-7) with three Savonius-type VAWT (8). The HAWT of 1KW capacity is chosen with a rotor diameter of 3.048m and a tower height of 4.115m. Three Savonius-type VAWTs each with 1KW capacity are chosen with a rotor diameter of 0.65m and a height of 0.85m. In Variant-1, three Savonius-type VAWTs are kept at an optimum height on the HAWT tower and they are mounted at a 120° angular gap to overcome the vibrational difficulties. The total peak capacity of Variant-1 is about 4KW using a generator in HAWT and three generators (9) in VAWT.
With reference to Figure 2, the hybrid wind turbine (Variant-2) is developed in accordance with an embodiment of the present disclosure. In Variant-2, the hybridization is done by combining a three-bladed HAWT (1-7) with three tapered Savonius type VAWT (8). The HAWT of 1KW capacity is chosen with a rotor diameter of 3.048m and a tower height of 4.115m, the same as Variant-1. Three tapered Savonius type VAWT with a total capacity of 2.5KW are chosen with a rotor diameter of 0.35m, 0.5m, and 0.65m; and height of 0.85m, 0.75m, and 0.65m respectively. In Variant-2, three tapered Savonius-type VAWTs are kept along the axis of the HAWT tower and they are mounted at equal intervals to overcome the vibrational difficulties. The total peak capacity of Variant-2 is about 3.5KW using a generator in HAWT and a permanent magnet generator (9) in VAWT.
An automatic safety system (10) is used in this invention to safeguard the hybrid turbine by tightening the guy wires using motors in heavy and turbulent wind. An automatic stalling system (11) is used in this invention to stop the HAWT by a gear drive breaking system and VAWT by using three closing flaps to overcome the issues during heavy winds at extreme climate conditions. The automatic control of the motors in the safety and stalling system (10, 11) is carried out from the inputs of wind speed and directional sensors. , Claims:The scope of the invention is defined by the following claims:

Claim:
1. A Hybrid Wind Turbine comprising:
a) A set of Savonius vertical axis wind turbines (8), each kept at 120 degrees apart at an optimum tower height on HAWT to generate power at a low wind speed level for variant 1.
b) A set of tapered Savonius vertical axis wind turbines (8), each kept along the axis of the tower on HAWT to generate power at a low wind speed level for variant 2.
c) The automatic safety system comprising wind speed and directional sensors (10) is used to provide safety for the hybrid wind turbine at very high wind speed by tightening the guy wires through sensor-controlled motors.
2. As mentioned in claim 1, an automatic stalling system comprising wind speed and directional sensors (11) is used to stall the horizontal axis wind turbine at very high wind speed and turbulence situation through an electric motor and gear drive.
3. As mentioned in claim 1, three Savonius vertical axis wind turbines are fixed each at 120 degrees apart at an optimum tower height. This is responsible for avoiding major vibrations and tower failure due to wind loading. At the same time, it is responsible for power generation at lower wind speeds.
4. As mentioned in claim 1, three tapered Savonius vertical axis wind turbines are fixed along the axis of the tower at specified intervals. This is responsible for avoiding major vibrations and tower failure due to wind loading. At the same time, it is responsible for power generation at lower wind speeds.