Cosine Phase Droop Control (CPDC) for the Dual-Active Bridge in lighting smart grids applications

Lighting Systems are suffering and important evolution with the introduction of LED lighting systems with new strategies of energy savings, incorporation of renewable energy sources and optionally a bidirectional interconnection with the mains (AC grid or DC interconnection bus). Lighting Systems are moving to Lighting Smart Grids and step by step integrating in Smart Cities strategies. In this context design of modular and efficient energy storage/recovery systems are gaining importance looking for future applications and new services. Thus, this work evaluates the use of Dual-Active Bridge (DAB) as energy storage/recovery system in the context of a Lighting Smart Grid. A complete study of this converters, design procedure in order to operate over the Optimal Line (no reactive power) and two simplified control strategy (Linear Phase Droop Control - LPDC and Cosine Phase Droop Control-CPDC) have been proposed, developing in this way a robust design with modular and self-equalization capability. Designs have been simulated and tested over a laboratory Lighting Smart Grid obtaining satisfactory results.