Analysis and control of buck-boost converter with the same input polarity based on novel energy factor evaluation

الملخص EN

This paper presents firstly a buck-boost circuit with the advantage that its output voltage polarity is the same as the input polarity.

The circuit operation is presented and analyzed in different modes of operation.The well known parameters used in evaluation of DC/DC converters like Total Harmonic Distortion THD, Power Factor PF, and Ripple Factor RF have no meaning in DC/DC converters, so it is to introduce efficient concepts to permit a fair evaluation of the converter.

This paper present other parameters that can be used to study the characteristics of the converter and gives a real and logic means of its operation.

These main parameters are: pumping energy PE, storage energy SE, energy factor EF, and energy losses EL.

In addition, the converter efficiency is not considered as 100 % as taken in most analyzing studies.The positive DC/DC buck-boost converter is evaluated according to the new concepts and the system model is deduced for different cases of operation taking into account the resistance of the circuit inductor.

The circuit is implemented practically and the presented obtained results show the correct operation under different modes of operation.In addition the control design of the converter is built such that a PI controller with windup is considered.

In order to test the effectiveness of the designed control algorithm, the system were exposed to different voltage reference values and the obtained results demonstrate that the system responses for all cases are very acceptable according to the criteria of the control system theory.