Design of a constant current Load Resonant Converter using an LCLL tank with load regulation capability topologically

In this paper an LCLL tank is presented for application in Load Resonant Converters (LRCs) with the constant current output. Design method is based on the output current independence from load variation and minimization of kVA/kW ratio of the LC tank. A 150kHz 70W LRC is presented as an experimental prototype of the design procedure. This converter has a robust load regulation, minimum reactive power and ZVS on the inverter's MOSFETs over an extended load variation without using any feedback loop. Designed converter can be used for many applications with constant current such as LED drivers and battery chargers. Also, high efficiency is achieved and transformer's parasitic elements are integrated as components of the Passive Resonant Tank (PRT). Therefore order and size of the converter is reduced in this topology.