Design and implementation of the distributed control for parallel AC/DC converters

The distributed control strategy of a parallel connected single-phase AC to DC converter is presented. For flexibility of the system operation each converter module has its individual microcontroller. The microcontroller is used to control the output voltage and the data communication among the other controller via RS485 serial bus. By using the information is obtained from the data communication this uses for the current sharing of each converter module. In the current loop control, the hysteresis control circuit is applied in this paper. The PI controller is compensated in error of the output voltage. The modeling of the system is based on the power balance technique to achieve a transfer function of the system to design a gain value of the PI controller. The performance evaluation of the proposed system is based on the simulation and experimental results. A 750 W load with a -48V output voltage laboratory prototype is implemented and tested to verify the feasibility of the proposed system.