VARIABLE-SPEED DRIVES:INPUT POWER CONVERTER (RECTIFIER) AND DC LINK ENERGY

INPUT POWER CONVERTER (RECTIFIER)

Regeneration is not required in most cases. A simple diode bridge is used as an input power converter (Fig. 10.5).

DC LINK ENERGY

This is a bank of electrolytic capacitors (high-capacitance). If normal capacitors were used, the diode bridge output current would be very discontinuous and the resulting ac input power factor would be very poor (as low as 50 percent) due to the very high levels of harmonics. An inductor in series with a capacitor (Fig. 10.3) is used to correct the problem.