Electronic motor starters and drives
Frequency inverters DF5, DV5, DF6, DV6
Design and mode of operation
Frequency inverters convert constant mains voltage and
frequency into a DC voltage, from which they generate a new three-phase
supply with variable voltage and frequency for the three-phase motor.
The frequency inverter draws almost only active power (p.f. ~ 1) from
the supplying mains. The reactive power needed for motor operation is
supplied by the DC link. This eliminates the need for p.f. correction on
the mains side.
Rectifier
DC link
Inverter with IGBT
Open-/closed-loop control
The frequency-controlled three-phase motor is today a
standard component for infinitely variable speed and torque regulation,
providing efficient, energy-saving power either as an individual drive
or as part of an automated installation.
The possibilities for individual or plant-specific coordination are
determined by the specific features of the inverters and by the
modulation procedure used.
Rectifier 
DC link 
Inverter with IGBT 
Open-/closed-loop control 
