Source Current Feedback based Virtual Impedance Control for Three Phase Interleaved DC-DC Converter

An interleaved converter is integrated with a DC-AC inverter to achieve varying output AC voltage while keeping the inductance, capacitance, and device ratings low. The DC-AC conversion leads to second-order ripples (SORs) in the voltage and currents on the DC side. The second-order ripple currents (SRCs) tend to propagate through the interleaved converter to the source because of the low value of the passive components in an interleaved converter. These ripples cause an increase in power loss, rise in temperature, electrode degradation in the battery, and affect the operating life span of sources. In this paper, a Source Current Feedback based Virtual Impedance Control (SCF-VIC) is proposed which virtually increases the inductance in series of the source of the interleaved converter, at a desired frequency. The proposed (SCF-VIC) consists of a proportional-integral controller and a virtual impedance control block. The source current is fed into the control loop through a filter whose gain is modified in order to achieve a varying impedance. The proposed control reduces the second-order harmonic currents and does not affect the transient performance of the converter at other frequencies. The proposed SCF-VIC has been verified to reduce the SRCs through simulation and experimental verification.