Wind Turbine Generator (WTG)

A wind turbine generator, or WTG, converts the kinetic energy of moving air into electrical power through an aerodynamic rotor, a drive train, and an electrical generator system. Modern utility-scale WTGs are sophisticated controlled machines rather than simple mechanical turbines, with performance governed by aerodynamics, converter control, and grid-code compliance.

Wind generation varies with wind speed, turbulence, air density, and turbine control mode. The plant must therefore continuously adjust rotor speed, blade pitch, and electrical output to maximize capture at moderate wind while limiting loads and protecting equipment at high wind.

Key Aspects of Wind Turbine Generators:

• Aerodynamic Conversion: The rotor extracts part of the energy in the wind and converts it into mechanical shaft power. That conversion depends strongly on blade design, tip-speed ratio, pitch angle, and local wind conditions.
• Modern Technology Types: Current large WTGs often use variable-speed operation with either doubly fed induction generator architecture or full-converter topology. The technology choice affects converter behavior, fault response, and grid-support capability.
• Control Above and Below Rated Wind: Below rated wind speed, the control objective is usually to maximize energy capture. Above rated speed, pitch control and power limiting are used to keep output and mechanical loading within design limits.
• Grid Integration Role: Wind plants are not just energy producers, they also interact dynamically with the grid through converters, plant controllers, and reactive-power systems. Their contribution to voltage support, ride-through, and frequency response depends on control design and grid requirements.
• Site Dependence: Capacity factor and production profile depend heavily on wind regime, turbulence, wake losses, and whether the project is onshore or offshore. Good resource assessment is therefore central to both plant economics and system planning.