PROJECT TITLE :

Constant Resonant Current Limiting Strategy for LLC Converter Without Current Sensing

ABSTRACT:

There are great current shocks in LLC resonant converter during startup and over load condition. Standard open loop current limiting methodology suffers from restricted impact and sophisticated style method, whereas closed loop current limiting methodology needs further current sensing. This paper investigates the link between resonant current, output voltage, and switching frequency primarily based on state plane analysis, then a continuing resonant current limiting strategy without current sensing is proposed, which adjusts switching frequency admire the output voltage. The proposed strategy can notice constant peak price of resonant current throughout startup, shock load stepping, and over load condition, achieving optimal management of the first current stress. Together with standard output voltage regulating strategy, regulation of output voltage under traditional load condition is also guaranteed. The maximum available output voltage beneath current limiting condition is estimated, and easy parameter design methodology of current limiting strategy is provided.