Non-linear intermittent instabilities and their control in an interleaved DC/DC converter

The undesirable intermittent instabilities in periodically driven parallel power converter are caused due to periodic interferences in input voltage. This is a more common problem in power electronic circuit design and such operations are usually avoided by controlling the circuit parameters. In this study, the mechanism and conditions for the emergence of intermittent instabilities and remerging chaotic band attractors (or Feigenbaum sequences) in a master-slave controlled parallel buck converter are investigated. It is found that sinusoidal-type interference in input voltage at frequencies near the switching frequency or its rational multiples of this circuit results typically in period-bubbling, chaos and intermittency. It is also shown that an optimal, phase-shifted sinusoidal interference added to the reference voltage controls the period-bubbling behaviour and significantly extends the parameter range of desirable period-1 operation. The dynamics of this converter has been first investigated with suitable numerical simulations. The ordered and the chaotic dynamics of this system have been further mathematically described and analysed with a simple discrete map and experimental means. Experimental observations are found to be in good agreement with the analytical and simulation results.