Sumant G. Kadwane
DC–DC converter, sliding mode control, frequency domain
The most critical part in implementation of sliding mode (SM)
controllers is the prediction of stability with the selected modulation
technique: hysteresis or pulse width modulation (HM or PWM).
Another important aspect is the determination of hitting condition
to the sliding line/surface and the existence condition to remain
in the vicinity of sliding line/sliding surface. In this paper the
frequency domain interpretation of SM controller is presented.
A very simple graphical technique that can be easily applied to
higher order sliding surface is suggested using describing function
approach, which gives all information regarding stability and hitting
and existence conditions. In addition to this, the steady state
switching frequency and amplitude of oscillations is easily obtained
through the suggested technique.