Volume Reduction of an Integrated Magnetic in a Two-Stage Street-Lighting LED Driver

This paper proposes the volume reduction of an integrated magnetic in a two-stage LED driver, aiming to increase the system’s overall power density. The enhancement of the integrated magnetic design is detailed and compared with two standalone magnetics in the same LED driver configuration and using identical electrical and magnetic design specifications. This work’s main contribution and objective is the utilization of a different version of the integrated magnetic to decrease the total volume of the LED driver over the previous integrated magnetic design. To verify the feasibility of this change, the paper analyzes the theoretical equivalent magnetic circuits and simulation results using Finite Element Method (FEM) through Ansys Electronics® software, as well as PSIM software for core loss calculations, and efficiency was measured using the Yokogawa WT1800 power analyzer. The proposed design was validated by the implementation of a 180W two-stage street-lighting LED driver, which employs a Boost converter in critical conduction mode as the power factor correction (PFC) stage and a Buck converter in continuous conduction mode as the power control (PC) stage. Implementing the new integrated magnetic enabled a volume reduction of 40% compared to its earlier version. Furthermore, an additional advantage of this work was the LED driver global efficiency increase of at least 0.15% throughout the entire LED dimming range, between 10 and 100% of the load nominal operation, in comparison to the prototype with the prior integrated magnetic. When the efficiency enhancement is compared with the commercial LED driver, there is an efficiency improvement of over 1.2% through the same LED dimming interval, without any electrical modifications in the LED driver itself.