On the voltage pulse-width modulation control of L-C filters

Pulse-width modulation is broadly used to control electric and electronic d evices. The operation of many of these devices is based on the control of t he output voltage of a passive filter. Their controllers are designed from the approximate linearization of the dynamics of the joint system, filter-p ulse width modulation strategy, which is strongly nonlinear, Common lineari zation techniques work fine when the modulation frequency is much larger th an the natural frequencies of the filter, but fail when that frequency is o f the same order of magnitude or smaller than these filter frequencies, as happens in power electronic circuits. This paper develops a new linearizati on technique that allows a very precise control of these devices when small modulation frequencies have to be used, Our method permits the design of p ower electronic circuits with very fast output dynamic responses. An experi mental circuit is developed to test this and results are reported.