Filter design with uncontrolled rectifier and DC chopper

For supplying d.c. loads from the three phase a.c. input, a three phase uncontrolled rectifier and a d.c. chopper is often employed. In this system, a number of resonant conditions can occur if the filter frequency ff, the chopper frequency fcand the frequency foof the a.c. component in the d.c. load are not selected properly. This paper provides an analysis of the system employing Fourier Analysis and switching functions. Theoretical results have been verified on an experimental set up and the design guidelines for the filter components are established.