Analysis and Control of Modified DC-DC Cuk Converter

This paper proposes a control method for the modified dc-dc Cuk converter. The proposed modified dc-dc Cuk converter has an advantage compared to the conventional dc-dc Cuk converter. The output voltage polarity of this proposed converter is not reversed as in the conventional dc-dc Cuk converter, while the input and output currents are continuous similar to the conventional dc-dc Cuk converter. To control the proposed converter, a simple double loop controller is used. The outer loop controller is controlling the output voltage and the inner loop controller is controlling the inductor current. The inner loop and the outer loop are designed as propotional-integral (PI) control. The analytical approach for designing the control scheme is conducted by linearizing the small-signal model of the proposed converter to form the inductor current and output voltage transfer functions. These transfer functions will be analyzed by using phase and gain margin aproach to obtain the control parameters (Kp, Ki, and Ti). Simulated and experimental results are included to show the validity of the proposed concept.