Average current mode controlled DC - DC converter using digital controllers

摘要

A current fed push pull converters cascaded with a buck pre-regulator is proposed. Voltage stress of the push pull switches is reduced by buck pre regulation. Pulse width modulation is done only to the switch in buck stage. Output voltage and the buck inductor current is controlled using average current mode control. The closed loop simulation of a 20W,100V,0.2A cascaded buck push pull converter with analog control circuit is done using PSIM. Closed loop simulation using digital control circuit is done by using a SIMCOUPLER module which couples power electronic circuit in PSIM and digital control circuit in MATLAB. Further, hardware implementation of digital controllers on two platforms is explained. Switching pulses are generated using digital circuit are fed to the converter switches and the converter is tested for the open loop operation.