FPGA based parallel connection system of separate voltage sources

In this study, parallel connection of separate voltage sources has been realized using cuk converters. For this aim, output voltages of converters are measured continuously and then fixed to a reference value. The PWM signals which are required to control the converters and to sense the current and voltage signals are generated by an FPGA. Since the FPGA has parallel processing feature, voltage and current data of the system are measured at the same time. Thus, the converters are connected in parallel punctually and load sharing between them are provided in order to eliminate some undesired cases like unbalanced loading. In the system realized, two identical cuk converters are used. As cuk converters can operate both in buck and boost modes, output voltages are fixed to the reference voltage successfully, even though input voltages are low or high. Experimental results show that the system achieved operates with a reasonable efficiency ranging from 81% to 88%.