Patent ID: 8933652
Filing Date: 2015-01-13
Classification: F03D,F05B,Y02E

Abstract:
1. A rotor-blade pitch controlling drive for a wind turbine comprising: a control system; an electrical working load; an electrical test load; a primary energy supply supplying electrical energy for the electrical working load; an intervening converter, the working load being electrically coupled to the primary energy supply via the intervening converter, the converter being coupled to the control system by means of which the converter is actuated to turn a rotor-blade on a blade axis; an electrical energy storage means which is operable to be electrically coupled to the working load and by means of which the working load is operable to be supplied with electrical energy if the primary energy supply fails, while the electrical test load is uncoupled from the electrical energy storage means; an electrical switching arrangement responsive to the control system, the electrical switching arrangement configured to directly couple the electrical energy storage means to the working load when the primary energy supply fails, the electrical switching arrangement being controlled by the control system; a charger operable to charge the electrical energy storage means; and an analyzing arrangement configured to analyze an electrical discharge of the electrical energy storage means at successive intervals; at each one of the successive intervals, the control system operating to: