Envelope Following Analysis Method of Autonomous Power Electronic Circuits

The 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 algorithm. 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 non-autonomous systems. This paper proposes a new extended EF method which can also analyze autonomous systems which are typical in the power electronics field. It is extended by introducing a switching condition to the original one and the two 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 C´uk converter examples are investigated and validated.