Improved Dynamic Response of Coupled Inductor-Based High-Step-Up-Gain DC–DC Converter Using Interleaved Technique

The closed-loop control of coupled inductor-based high-step-up-gain boost converter in continuous conduction mode has non-minimum phase behavior due to right-half-plane (RHP) zero. The crossover frequency of the closed loop should be designed to be less than RHP zero for stable converter operation. Hence, the converter has lower bandwidth (BW) and a poor dynamic response. Combining the interleaving technique with coupled inductor boost converter (CIBC) can improve the dynamic response. As the number of interleaved phases at the input side of CIBC increases, RHP zero moves toward higher frequency. Thus, it improves the closed-loop BW. In addition, it is simple and easy to design closed loop of interleaved coupled inductor boost converter (ICIBC). Moreover, an interleaved operation reduces the size of inductance required for the same ripple in input current and reduces voltage dip during a step change in load. This paper presents a small-signal model of a multi-phase ICIBC to verify the claim. The laboratory prototype of CIBC and three-phase ICIBC is implemented to boost 24 V to 100 V at power level of 300 W. The experimental results of CIBC and three-phase ICIBC are obtained for a change in load from 150 to 300 W to validate results of small-signal model. A single-loop voltage mode control with Type II controller is implemented to regulate output voltage and to achieve desired dynamic performance of three-phase ICIBC for a load disturbance.