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This paper presents a novel non-isolated capacitor-assisted quasi-Z-source (CA-QZS) multiport DC-DC boost converter, which operates as a dual-input single-output high gain boost converter. It consists of a bidirectional port for the smooth operation of the energy storage system, and a unidirectional port for the solar/fuel cell to deliver power to the battery and the load. The availability of common ground between input and output ports, high voltage conversion ratio, and continuous current of the unidirectional port are the main features of this novel design, making it suitable for a wider range of applications. A typical switching strategy is followed to regulate the output voltage as well as control input power from the sources. As a battery-incorporated system, the converter's performance is determined by its selection between three operating modes. Therefore, the CA-QZS converter offers a viable interface for the management of battery energy storage systems. A comparative study is performed with other multi-port converters to highlight the advantages. It is observed that the voltage conversion ratio of 10, can be achieved at a low duty ratio of 0.3. To evaluate the effectiveness of the proposed topology, a prototype is developed with a nominal output power rating of 200W and an output voltage of 200 V. [ABSTRACT FROM AUTHOR]

There is a requirement for a suitable DC-DC converter which can exhibit satisfactory performance in the case of OFF-Grid PV systems. This paper proposes a PV-Battery stand-alone system with an enhanced DC-DC boost converter and an efficient voltage balancing technique. The converter is designed to achieve the desired voltage gain at a lower duty-ratio as compared to the existing converter topology used in conventional stand-alone systems, thereby reducing the voltage stress across the switching devices. For extracting maximum power from the solar panel at every given point of operation, the Incremental Conductance Technique is used. A non-complex voltage balancing technique maintains the DC bus voltage constant with fast dynamic response. The system is highly reliable in case of converter fault and exhibits less initial transient time each time it is put to test. The performance of the proposed system is tested under varying input and varying load conditions with maximum overall system efficiency of around 93%. The stability of the system is investigated using a small signal model of the converter. The proposed stand-alone PV/Battery system is designed to handle a 1 KW load at 180 V DC voltage fed by 1.5 KW solar panel and 100Ah/24 V Li-ion Battery. The dynamic performance of the proposed system is verified through OPAL-RT 4510 platform. [ABSTRACT FROM AUTHOR]