Rotor blade pitch control system for wind turbine generating electricity has DC supply for motor with parallel-wound and series-wound field coils with diode bypassing series field coil during braking

摘要

The DC motor (5) is connected across the terminals of a DC supply (U+,U-) with an accumulator battery (10). A switch is connected in parallel with a control circuit (65). The motor current (I A) flows through a fixed resistor (64) to the motor. When the current is flowing forward (I E), the motor current flows through a series-connected field coil (51) and the motor armature (50). When the motor is braking, the armature current is reversed and flows through a diode (7), bypassing the series field coil. A fixed parallel field coil (52) is permanently connected across the supply terminals.