Silicium-Carbide-Based Isolated DC/DC Converter for Medium-Voltage Photovoltaic Power Plants

Abstract

The production of large-scale photovoltaics (PVs) is becoming increasingly popular in the field of power generation; they require the construction of power plants of several hundred megawatts. Nevertheless, the construction of these PV power plants with conventional low-voltage (LV) conversion systems is not an appropriate technological path. Particularly, large cross-section cables, a high quantity of semiconductors, and the bulky layout of 50/60-Hz step-up transformers make the PV system less competitive in terms of energy efficiency and cost. To overcome these drawbacks, this paper introduces new PV plant topologies with an intermediate medium-voltage direct current (MVDC) collector that requires galvanic isolation for connecting the PV arrays. Then, the design of a power electronic transformer (PET) is proposed, implementing 1.7-kV and 3.3-kV silicium carbide (SiC) power modules. The study confirms that this converter allows the use of medium-frequency (MF) transformers with high power densities while maintaining high efficiency, which facilitates the implementation of isolated medium-voltage (MV) topologies for utility-scale PV power plants.

Research on HSQZSC converter with integral sliding mode control

“…Photovoltaic grid connection is one of the ways to utilize renewable energy, and with the continuous expansion of installed capacity and the gradual maturation of technology, DC converters have become an indispensable part of grid-connected systems [1,2,3,4,5,6]. Currently, various types of converters have been researched, including coupled inductor [7,8], switched inductor [9,10], switched capacitors [11,12], and hybrid switched inductor and capacitor [13,14].…”