Drivetrain Gearbox

The gearbox options in Bladed support either a geared or direct drive system. In the geared arrangement the aerodynamic torque is transmitted through the low-speed shaft to a gearbox that then transforms the speed and torque to a high-speed shaft that can then connect to a generator. In this case electricity generation is done with at high-speeds and low torque values. A direct drive transmission instead transmits the aerodynamic torque and rotor speed directly to the generator rotor.

An overview of the different options can be obtain by reviewing the multibody diagrams.

The gearbox has two properties:

GearboxRatio: The ratio of the high-speed shaft (connected to the generator) to the low-speed shaft (connected to the rotor).
GearboxInertia: The total rotational inertia of the gearbox, referred to the high-speed side.

Direct-drive transmission types can be modelled by setting the GearboxRatio to 1, like in the example below:

    "GearboxRatio": 1.0,
    "GearboxInertia": 0.0,

For a geared configuration:

    "GearboxRatio": 83.33,
    "GearboxInertia": 435432.0,

If the low-speed and high-speed shafts rotate in opposite directions the user can specify the GearboxRatio to be a negative value.

The inertia of the low-speed shaft, high-speed shaft and the gearbox should all be included in the GearboxInertia, however, if a slipping clutch is defined, then the inertia of the high-speed shaft should be included there. See rotational inertia of the drivetrain for more details.

Note

The mass of the gearbox should be included in the nacelle mass definition.

Table of Contents

Drivetrain Gearbox

Note