Quadrant operating control for current regulated three=phase machine - with drive and braking for both rotation directions which varies pole control angle with controlled thyristor firing sequence

摘要

The control circuit provides a differing pole control angles, e.g. the angle between the stator current and the pole wheel voltage. It uses a multiple of six detectors supplying pulses to a logic coupling circuit, together with signals representing the required pole control angle. The logic coupling circuit delivers output signals to six parallel lines coupled to individual rectifiers in the AC bridge circuit for the machine, to maintain the required cyclic sequence. Pref. the four pole control angles used are 0, 60, 120 and 180 degrees, with the first and last used for low rotation rates, below 10 per cent of the normal rotation. The thyristor bridge circuit pref. comprises three pairs of parallel thyristors (R1, R2; S1, S2; T1, T2) the machine windings coupled to the junctions between respective pairs.