Four-quadrant drive as fast operating and precise dynamometric brake

Abstract

An industrial induction machine drive designed for energy recirculating dynamometric brakes is presented. A mains side IGBT-inverter manages both energy flow directions with unique power factor and sinusoidal currents. It connects the DC-link to the supply network with very low distortion and a second IGBT-inverter supplies the brake. Field oriented control of the induction machine and a new software current controller ensure low torque ripple and excellent dynamic behaviour of the shaft torque. The pendulum dynamometer design of the brakes provides robust and precise torque measurement. A built in torque calculator completes the transient torque monitoring. Dynamometric brakes from 100 to 440 kW with several speed ranges up to 18,000 r/min are available.