Comprehensive Small Signal Modeling of the DC/DC Converters with CDM Controller Design

In this paper the DC/DC buck, boost and buck boost converters mathematical models are developed by average state space technique. Since the converters possess nonlinear and time variant characteristics, so to linearize them and stabilize the output voltages their small signal models have been developed using the average state space models. These small signal models are useful to derive voltage and current transfer functions and hence easy to design controllers to obtain the regulated output voltage. This paper pay attention on the step by step development of the small signal models for all the converters and also the design of dual loop CDM controllers for buck boost converter to attain desired voltage at output. The output response curve settles down fast with negligible overshoot and steady state error.