Improved DC-Link Voltage Regulation Strategy for Grid-Connected Converters

In this article, an improved dc-link voltage regulation strategy is proposed for grid-connected converters applied in dc microgrids. For the inner loop of converter, a modulated direct power control employed to obtain two second-order linear time-invariant systems, which guarantees that closed-loop system globally exponentially stable. outer loop, sliding mode with load current sensor maintain constant even presence loads at dc-side, adversely affect stability. Furthermore, observer designed remove same time improving reliability and decreasing cost. From both simulation experimental results obtained from 15-kVA prototype setup, method demonstrated improve transient performance has robustness properties handle parameter mismatches compared input-output linearization method.