Advantage And Disadvantage Of Wind Turbine

Heating of the earth's surface by the sun is uneven, causing large air masses to move on the surface of the earth and the wind can be defined as air in motion. Wind energy conversion systems convert the kinetic energy of the wind into electricity or other forms of energy. The wind turbine extracts the kinetic energy of the wind and produces rotating torque and the generator utilizing this torque produces electrical energy, which is fed in to the grid. Wind turbines are of two types: vertical axis type and the horizontal axis type. Modern wind turbines mostly utilize the horizontal axis configuration having two or three blades, which operate either down-wind or up-wind.

A wind turbine shall be designed for a constant speed or variable speed

Capacitors and reactors have been used with mechanical switches for controlling var generation and absorption during the early days of ac power transmission. Over or under-excited rotating synchronous machines provide continuously variable var generation or absorption for dynamic system compensation. During early days, thyristors in association with capacitors and reactors were used to provide variable shunt impedance by synchronously switching shunt capacitors and/or reactors. Recently, gate turn-off thyristors with internal turn off capability have been employed to generate and absorb reactive power. These perform as ideal synchronous compensators, in which the magnitude of the internally generated ac voltage is varied to control the var output. All the semiconductor power circuits, with their internal control, enable them to produce var output proportional to an input reference, are known as static var generators (SVG). Static var compensator (SVC) is defined as static var generator whose output is adjusted to maintain or control certain specific parameters of the power system. Recently, for reactive power control, the Voltage Source Inverter (VSI) based Static VAR compensators have been used. These compensators are known as Advanced Static VAR Compensator or Static Synchronous Compensator (STATCOM).