Novel on-line parameter tuning technique for predictive current mode control operating in boundary conduction mode

The objective of this paper is to present an on-line parameter tuning technique for digital power converter with predictive peak current mode control operating in boundary conduction mode. The issues caused by both inductor variation and input voltage drift can be solved by the proposed on-line parameter tuning technique which is based upon the sampled currents between two PWM outputs. The proposed technique requires neither additional sensor nor system parameter. Furthermore, the effects of inductor variation and input voltage drift are analyzed. It will be demonstrated that the variation of inductor and input voltage drift result in DC offset of inductor current and deteriorates the performance. It will be confirmed by experimental results that these effects can be coped with using the presented on-line parameter tuning technique. Experimental results derived from an FPGA-based digital controller will be presented to fully confirm the theoretical analysis.