WIND POWER ENERGY

M.M.Palitha Mahinda MunasingheFarm Mechanical Instructor

palithamahinda@yahoo.com

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• Harness and plentiful energy source

• It is green, renewable energy and doesn't release any harmful pollutants• It is free, wind farms need no fuel

• The land beneath can usually still be used for farming

• A good method of supplying energy to remote areas

The Benefits Of Wind Power Energy

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• The wind is not always some days have no wind

• Suitable areas for wind farms are near the cost, where land is expensive

• Can kill migrating birds flocks tend to like strong winds

• Can affect television & Radio transmission signals

• Can be noisy day and night

Difficulties' of Generate Wind Power Energy

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Wind Tower Components

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Energy Transfers

Wind turbines convert the kinetic energy from the wind into mechanical energy

which is then used to drive a generator that converts this energy in to electricity

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Generated power is transferred through conductive wires directly to a home, grid connection system for wider spread use or a battery storage system

Battery banks store the power for later usage and employ a regulator to avoid overcharging incidents

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Horizontal-axis wind turbines (HAWT)

• The main rotor shaft and electrical generator at the top of a tower• Must be pointed into the wind• Small turbines are pointed by a simple wind vane• Large turbines generally use a wind sensor coupled with a servo motor• Most have a gearbox( which turns the slow rotation of the blades into a quicker rotation that is more suitable to drive an electrical generator)

Vertical-axis wind turbines (or VAWTs)

• The main rotor shaft arranged vertically• Turbine does not need to be pointed into the wind • On sites where the wind direction is highly variable is most suitable• The generator and gearbox can be placed near the ground• It could direct drive from the rotor assembly to the ground-based gearbox (hence improving accessibility for maintenance)

Type of wind Turbines

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The rotor component

Includes the blades for converting wind energy to low speed rotational energy. Which is approximately 20% of the wind turbine cost

The generator component

Includes the electrical generator, the control electronics, and most likely a gearbox (e.g. planetary gearbox, adjustable-speed drive or continuously variable transmission) component for converting the low speed incoming rotation to high speed rotation suitable for generating electricity. Which is approximately 34% of the wind turbine cost

The structural support component

Includes the tower and rotor yaw mechanism. Which is approximately 15% of the wind turbine cost

Turbine Design

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Vertical axis wind turbine designs could immediately convert wind into a rotation

This means that they are actually turning more consistently than most of the horizontal axis designs and provide a more consistent output of power

Horizontal-axis wind turbinesVS

Vertical-axis wind turbines

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Turbine Design

Designed and validated should be according to IEC 61400 standards Typical operating temperature range is -20 to 40 °C Designed for a maximum wind speed The survival speed of wind turbines is in the range of 40 m/s to 72 m/s

Horizontal axis wind turbines

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Blades Designs

• The ratio between the speed of the blade tips and the speed of the wind is called tip speed ratio

• High efficiency 3-blade-turbines have tip speed/wind speed ratios of 6 to 7.

• Modern wind turbines are designed to spin at varying speeds

• Use of aluminum and composite materials in their blades has contributed to low rotational inertia

• Newer wind turbines can accelerate quickly if the winds pick up

• It keeping the tip speed ratio more nearly constant

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Aluminum and composite materials to build blades has contributed to low rotational inertia

Fiberglass-reinforced epoxy material

Most horizontal wind turbines settled on a 3-blade design, which gives the best balance of stability and rotor speed

Blades Designs

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Blades Designs

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• In simple designs the blades are directly bolted to the hub• More sophisticated designs, they are bolted to the pitch mechanism • Which adjusts their angle of attack according to the wind speed to control their rotational speed• The pitch mechanism is itself bolted to the hub• The hub is fixed to the rotor shaft which drives the generator through a gearbox

The hubPitch mechanism drive turbine

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1. Control panel2. Nacelle3. Generator stator4. Generator rotor5. Blade root6. Pitch drive7. Nose cone8. Main hub9. Tower10. Yaw drive

Direct drive turbine The hub

• Direct drive wind turbines are constructed without a gearbox• Its’ rotor shaft is attached directly to the generator (which spins at the same speed as the blades)

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Tower DesignLattice Tower

It is often called a self-supporting tower. Lattice towers are generally made out of steel and offer the most stability of the tower types. A lattice tower can be found in either a square or a triangular shape. The lattice towers offer the most flexibility of all of the tower types.

Monopole Tower

A monopole tower features a single tubular mast. Because of their instability, a monopole typically does not exceed 200 feet high. However, these towers require the least amount of space on the ground.

Guyed Tower

Guyed towers are similar to a monopole tower in that they consist of a single tubular mast. However, a guyed tower utilizes guy wires to help with stability. These guy wires require a larger piece of land for the tower to rest on. This type of tower is often the cheapest to build, especially at heights over 300 feet.

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Inside assemble

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Inside assemble

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The speed of wind blowing in your locality should be at least 3-5m/s

Wind turbine should be installed in such a place which is away from obstacles

The survival speed of commercial wind turbines is in the range of 40 m/s (144 km/h) to 72 m/s (259 km/h)

The most common survival speed is 60 m/s (216 km/h)

When It Produce Electricity

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Permanent magnet DC motor

Motor Design

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Modes of Operation

Below rated wind speed operation

Around rated wind speed operation

Above rated wind speed operation