Digital Resistive Current 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. Converting the effective input characteristic of the converters seen by the source as a resistive load sink for current sharing, the proposed control scheme achieves current mode control, like the conventional analog charge current mode control. Also, the sub-harmonic 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 operated in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The complete small signal model with the digital sampling effect is developed to perform the stability analysis and the design guideline. For the design example, two 100W parallel module buck converters with a TMS320F2812 DSP has been built and tested by using the proposed DCR control.