Abstract:
The analysis and design of paralleling ac to dc three-phase configuration using isolated
CUK rectifier modules based on power balance control technique with nearly unity power factor
and fast transient response for DC Distributed Power System (DPS) applications are presented.
The power balance control technique is used to obtain the three-inductor current compensators, as
a result, the output voltage of the converter can withstand the variations of the dc load current and
the source voltage. To improve the dynamic performance, minimal total harmonic distortion
(THDi) in the source current and inductor currents sharing, a proposed control method is
employed in the voltage feedback loop. The proposed procedure of analysis is simple and
effective. The implementation of this control circuit uses only analog circuitry. The experimental
prototype has been built with a DC output voltage -48 V and output power 1.5 kW. Each converter
operates in Continuous Conduction Mode (CCM) together with hysteresis current control. The
experimental results indicate that such scheme is effective and offers the fast transient response.
The results obtained are : power factor greater than 0.99 and input current Total Harmonic
Distortion less than 3%. The system offers 86% efficiency and provide good current sharing
among the converter modules. Simulation, using Simulink, and experimental results are presented
to verify the feasibility of the control strategy.