Limit cycles in periodically switched circuits

Examines the existence, uniqueness, and stability of limit cycles in periodically switched circuits, such as those used in power electronic and power conditioning applications. The main results relate the existence and uniqueness of limit cycles in these switched circuits to the analogous properties of equilibrium points in nonswitched averaged models for these circuits. The results are applicable to two types of circuits. First, the author considers circuits built from incrementally passive (or locally passive) elements including DC sources and ideal switches in which the switches are operated periodically in an open-loop manner. Second, the author introduces an averaging procedure based on the describing function method. This procedure is then used to study limit cycle stability in closed-loop DC-DC converters