Non-isolated high step-up DC/DC converter for low-voltage distributed power systems based on the quadratic boost converter

摘要

Distributed energy resources have been broadly developed in recent years for supporting DC and AC microgrids. Unfortunately, most of them produce low output DC or AC voltages, and interfacing converters are required. These are implemented either in single-stage or dual-stage configurations. Step-up converters are the essential section in dual-stage designs, which their producing gain is important. Improving the boost factor and efficiency as well as decreasing the number of required components and electrical stresses on power components are the most critical challenges in designing such topologies. Continuing past efforts, this paper proposes a new non-isolated step-up DC/DC converter that can be used in low-voltage distributed power systems and many other applications requiring step-up DC/DC conversion. The topology requires only one power switch located on the converter's low voltage (LV) side. Hence, it can be easily selected from LV ratings, low on-resistance power semiconductors. Besides, the converter operates with a continuous input current, which is a valuable feature in connection with current-sensitive voltage resources. Compared with the recently proposed topologies, the topology provides better conversion gain and efficiency. In this article, the operating principle of the introduced converter is comprehensively investigated. Also, in order to examine the converter performance, experimental results will be presented and analyzed. For this purpose, a 400 V/400 W prototype has been designed and built. Results confirm the above claims and show that the converter efficiency equals 96.1, and it produces high output voltage gain about 12 times.