Parameters	Description	Unit	Referred to the mass of the generator
$k_{g e a r}$	Gearbox ratio
$J_{g e n}$	Generator inertia	kg・m²
$J_{w t r}$	Wind turbine rotor inertia	kg・m²	${J^{'}}_{w t r} = \frac{J_{w t r}}{k_{g e a r}}$
$K_{s h a f t}$	Shaft stiffness	N・m/rad	${K^{'}}_{s h a f t} = \frac{K_{s h a f t}}{k_{g e a r}^{2}}$
$D_{s h a f t}$	Shaft damping coefficient	N・m・s/rad	${D^{'}}_{s h a f t} = \frac{D_{s h a f t}}{k_{g e a r}^{2}}$
$T_{g e n}$	Generator torque	N・m
$T_{w t r}$	Wind turbine rotor torque	N・m	${T^{'}}_{w t r} = \frac{T_{w t r}}{k_{g e a r}}$
$Ω_{g e n}$	Speed of the high speed shaft	rad/s
$Ω_{w t r}$	Speed of the low speed shaft	rad/s	${Ω^{'}}_{w t r} = k_{g e a r} \cdot Ω_{w t r}$
$θ_{g e n}$	High speed shaft angular position	rad
$θ_{w t r}$	Low speed shaft angular position	rad	${θ^{'}}_{w t r} = k_{g e a r} \cdot θ_{w t r}$
$T_{s h a f t}$	Internal shaft torque	N.m