Introduction
Despite their stability and robustness against parameter, line, and load variations (i.e. their ability to handle large transient disturbances) [1], sliding mode (SM) controlled power converters generally suffer from significant switching frequency variation when the input and load is varied [2], [3]. Variable switching frequency operation complicates the design of the input and output filters and designing of filters under a worst-case (lowest) frequency condition will result in oversized filters. Hence, it is desirable to operate the converters at a constant switching frequency that does not deviate too far from its nominal value.