Design of a high-power rectifier locomotive

RECTIFIED SINGLE-PHASE POWER is not direct current in the usually accepted sense of the term. If the circuit has no inductances, a pulsating direct current is produced; each pulse being the upper half of a sine wave. Actually, the lower half of the sine wave has been inverted above the zero axis. If sufficient inductance can be added to the rectifier output circuit, the pulses can be smoothed out, but the amount required is so high as to be impractical. A reactor of reasonable size can be designed, however, if the ripple in the output current is held to approximately 20 per cent with maximum motor currents.