A unified switching strategy in bidirectional grid interface DCM flyback stages for public street lighting systems with microgeneration capability

This paper defines, explains and implements a unified switching pattern for the switches in a bidirectional Discontinuous Conduction Mode (DCM) Flyback converter, used for connecting the individual elements of a street lighting system to the mains facility. In every individual element, the DC bus links the different existing stages, such as lamp driver, energy storage stage, power generation stage and Power Factor Correction (PFC) grid interface. The proposed switching patterns enable for a smooth transition between the behavior of the grid interface stage from inverter to rectifier mode, therefore enabling for a unified control method of the converter, valid for every operation condition. The output of the proposed strategy provides the pulses of every switch in the converter in the adequate sequence, therefore simplifying the design and implementation of the power and control stages. The proposed switching pattern is validated through simulation and experimental results.