Envelope Following Analysis of an Autonomous Power Electronic System

Envelope following (EF) method is an approximate transient simulation technique which considers switching dynamics. It skips analysis of several switching cycles and considers the cycles by using, for example, the backward Euler or the trapezoidal type algorithms. It is more accurate than the averaging method because it considers switching ripples and it is still efficient. However it has been proposed only for a non-autonomous system. This paper proposes a new extended envelope following method which can also analyze an autonomous system which is typical in the power electronics field. It is extended by introducing a switching condition concept to the original form and the EF and switching conditions are solved simultaneously. In the numerical process, a Jacobian matrix is evaluated where switch timing sensitivities are considered. A hysteresis controlled buck and a cuk converter examples are shown