Digital Resistive Current (DRC) Control for the Parallel Interleaved DC-DC Converters

In this paper, a digital resistive current (DRC) control for parallel interleaved dc-dc converters is proposed. By converting the effective input characteristic of the converters seen by the source to a resistive load sink, the proposed control scheme achieves the current sharing. Also, the subharmonic oscillation at the light load is defined and the method to avoid this problem is presented. Thus, using this control method, it is possible to use the converters operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The complete small signal model in the discrete time domain is developed to perform the stability analysis and the design guideline. For the design example, a prototype hardware system with two 100-W parallel module buck converters with a TMS320F2812 DSP has been built and tested by using the proposed DRC control.