Local control of an ISOP push-pull converter with uneven load sharing

This paper discusses how load current can be unevenly shared among multiple modules in a DC-DC converter. Each module is controlled locally instead of using a supervisory controller or a master-slave approach. The goal is to have a truly modular converter. Focus will be given to an input series, output parallel (ISOP) configuration whose modules have a push-pull topology. A key challenge to overcome is interleaving the switching signals of the distributed modules. Sensorless current mode (SCM) control is implemented on separate FPGAs to digitally control each of the modules. Simulation and experimental results that support the proposed method are included.