Switched Link PWM Current Source Converters with Harmonic Elimination at the Mains

Novel switched link pulse-width-modulated (PWM) current source converters are presented. These converters supply a controlled dc current to the load with a concurrent elimination of selected harmonics in the ac mains. The new topologies permit minimal constraints to be formulated resulting in significantly more efficient PWM patterns than hitherto reported in the literature. A higher number of harmonics are thus eliminated at the mains for a given switching frequency while maintaining a control capability of the output dc current in a wide range. Simulation results confirm the theoretical findings. Also discussed in the paper is the selection of capacitor filters to mitigate the residual harmonics. Index Terms--Amplitude modulation, current source converter, harmonic elimination, pulsewidth modulation.