A mechanical system under strongly nonlinear potential and dissipative forces, with nonstationary perturbations having zero mean values, is studied. Proposing a special construction of Lyapunov function, the conditions are found, which do not influence asymptotic stability trivial equilibrium position system. These include requirements on disturbance-free relations nonlinearity orders between f...

Power electronic converters are non-linear time-dependent systems whose exact analysis without the use of computers is very difficult, and even using computer softwares requires a long time. Use of the state space averaging method, as will be mentioned, in addition to simplifying the analysis procedure which is a result of converting a time-dependent system to a time-independent one, reduces th...