Method and system for wind turbine braking
AssigneeGeneral Electric Company
InventorsJames Patrick Lyons, Albert Andreas Maria Esser, Paul Scott Bixel
Life of this patent
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Abstract
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.
Claims11
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;
- and
- a 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.
A method for braking a wind turbine coupled to a utility power grid, the method comprising detecting a loss of power in the utility power grid, and, in response:
- extracting energy from rotational inertia of the wind turbine via a generator and a generator converter and using the energy to charge a DC link capacitor;
- and
- using the extracted energy stored in the DC link capacitor to provide power to an electrically-powered blade pitch actuator via an emergency power supply bus to pitch turbine blades of the wind turbine into a feathered position.
Dependencies are inferred from the claim text.