A Single-Stage Bidirectional DC-AC Power Converter Applied In The Energy Storage Equipment Of Smart Grid

Since can reduce energy consumption and greenhouse gas emissions, smart grid is getting an opportunity to develop quickly, in recent years. As an indispensable link in the smart grid, energy storage technologies have got extensive attention. In this paper, the bidirectional DC-AC power converter, which connects energy storage equipment and grid, is the main study object. And this paper presented a single-stage bidirectional DC-AC power converter.The single-stage single-phase bidirectional DC-AC power converter was studied in the first place. This paper validated the feasibility of the converter from the perspectives of modulation strategies, modal analysis and power wastage.Then this paper presented a single-stage three-phase interleaving bidirectional DC-AC grid-connection power converter on the base of the theoretical analysis of the single-stage single-phase bidirectional DC-AC power converter, which was discussed above. This single-stage interleaving three-phase bidirectional DC-AC power converter applies to distributed generation systems with multiple storage batteries. This paper introduced the operation principle of the converter, illustrated its implementation method of digital scalar pulse-width modulation(DSPWM). Subsequently, the mathematical model based on LCL filter and the decoupled control model in the d-q rotating reference frame were built in this paper. After that, the overall control strategy of the single-stage interleaving three-phase bidirectional DC-AC power converter was analyzed. The paper specified the design approach of double close-loop control, which contains current inner loop and voltage outer loop.Finally, the result of the comparison between simulation and experimental indicates that the design programs for the single-stage bidirectional DC-AC power converter presented in this paper is feasible, and the control system is stable.