초록 ▼

Stored rotational energy in an operating variable speed wind turbine is used to pitch blades and brake the wind turbine in the event of utility power grid failure. In one embodiment, a generator IGBT converter and the main power utility grid IGBT converter supply control and pitch servo power during

Stored rotational energy in an operating variable speed wind turbine is used to pitch blades and brake the wind turbine in the event of utility power grid failure. In one embodiment, a generator IGBT converter and the main power utility grid IGBT converter supply control and pitch servo power during turbine deceleration, and a ride-through capacitor on a DC emergency power supply bus and the main DC link capacitor provide additional energy storage. In another embodiment, a step-down DC/DC power converter adds to the intermediate DC link of the power conversion system with the secondary of the step down converter powering both the hub pitch controller and the wind turbine control system.

대표청구항 ▼

[ We claim:] [1.] A wind turbine braking system comprising:a wind turbine including turbine blades, a control system, and an electrically-powered blade pitch actuator;a utility power grid;an emergency power supply bus for supplying power to the control system and the pitch actuator in the event of a

[ We claim:] [1.] A wind turbine braking system comprising:a wind turbine including turbine blades, a control system, and an electrically-powered blade pitch actuator;a utility power grid;an emergency power supply bus for supplying power to the control system and the pitch actuator in the event of a loss of power in the utility power grid;a generator coupled to the turbine blades;a generator converter coupled to the generator;a DC link capacitor coupled to the generator converter; anda utility power grid converter coupled between the utility power grid and the DC link capacitor,in the event of a loss of power in the utility power grid, the generator converter being applied to extract energy via the generator from rotational inertia of the turbine blades and to use the extracted energy to charge the DC link capacitor for providing power to the control system and the pitch actuator via the emergency power supply bus to pitch the turbine blades into a feathered position.