PITCH MOTOR DRIVE CIRCUIT WHICH CAN OPERATE IN EMERGENCY MODE

摘要

The invention relates to a pitch drive circuit (50, 52, 54), which can operate in emergency mode, for a wind or water power plant (80), said circuit comprising at least one rectifier unit (14), at least one DC intermediate circuit (18), two inverter units (16-1, 16-2) and a pitch rotary current motor (38) with motor trains (30) which can be contacted on both sides. A first contact side (76-1) of the motor trains (30) is connected to a first inverter unit (16-1) and a second contact side (76-2) of the motor trains (30) is connected to a second inverter unit (16-2). At least one switching element (40) is connected to at least one contact side (76) of the motor trains (30). In a normal operating mode of a first switching state of the switching element (40, 44, 46), the motor trains (30) can be energized by means of both inverter units (16-1, 16-2), and, in an emergency operating mode of a second switching state of the switching element (40, 44, 46), the motor trains (30) can be energized by means of a single inverter unit (16). The invention further relates to a pitch drive device which is energized by an aforementioned drive circuit. Finally, the invention relates to a method for operating the pitch drive circuit which can operate in emergency mode.