Permanent Magnet Wind Turbine Generators
Permanent magnet synchronous generators are the ideal technology for low-speed primary movers applications such as wind turbines and micro-hydro-turbines. They are usually used in small-scale wind turbines as well as in large MW applications, up to 7-10 MW. They are characterized by high efficiency, high power density, and robust rotor structure compared to induction generators and switched reluctance machines.
A typical wind turbine [1]
Direct-drive Wind Turbine Generator Type
Most wind turbine drive trains currently use generators that are connected to gearboxes. The latter accelerates the rotation from the relatively slow speed of the turbine’s blades to the high speeds needed to generate electricity using a fixed-speed induction generator. Considering its many moving parts, the gearbox is one of the highest-maintenance components of a wind turbine. Direct- drive generator, is an alternative solution to generate electricity at much slower speed with fewer moving parts and reduced transmission losses; thus allowing flexible control and quicker response to wind fluctuations and load variations for variable speed wind turbines.
A 120 slots, 116 poles surface-mounted PMSM for wind turbine
Electric Machine Solution Package
The design of direct-drive generators is a challenging endeavor, especially for high Megawatt applications, where their size grows rapidly larger and heavier due to high torque requirements. To meet the design challenges of such machines and study the phenomena related to high-torque and low-speed generators, such as electromagnetic, thermal, mechanical, losses, and concentrated forces stress performances, a comprehensive and accurate Solution for electric machines is required. EMWorks motor simulators EMS, EMWorks2D, and MotorWizard are used to perform both 2D and 3D analyses of the wind turbine generator. The on-load analysis results of the wind turbine generator modeling are shown below.
For a fully resistive load, the magnetic flux and current density distributions at the base speed of 51.7 rpm are presented in the animation plots below.