QUESTION $3$

$($a$)$ A team of engineers from design department are required to design wind turbine to

provide energy to several housing areas located on an island. They need to find a

suitable type of generator based on the velocity of the wind that flows to the island and

the output demanded by the residences. The simple wind turbine design is shown in

Figure $3($a$).$ The wind flows at speed range of $20k\frac{m}{h}$ to $40k\frac{m}{h}$ to rotate the blades

and air density is about $1\mathrm{.}225k\frac{g}{m^3}$ at sea level. Based on the logical thinking, select

the suitable radius of rotor blade and suitable hub height to mount the blades. Then, by

assuming the tower is non$-$turntable, select suitable gear ratio to connect the turbine to

generator via main gearbox. The findings must include power acquired from wind,

power input to generator and power output. The assumption is using $Y$ connection $3-$

phase. Frequency electrical is set as $50Hz$ and efficiency is $85\%.$ The finding also needs

to include $V_{},V_T$ and selection of proper $I_a$

Figure $3($a$)$: The wind turbine diagram