Comparative Analysis of Semiconductor Power Losses of Galvanically Isolated Quasi-Z-Source and Full-Bridge Boost DC-DC Converters

Abstract

-This paper compares semiconductor losses of the galvanically isolated quasi-Z-source converter and full-bridge boost DC-DC converter with active clamping circuit. Operation principle of both converters is described. Short design guidelines are provided as well. Results of steady state analysis are used to calculate semiconductor power losses for both converters. Analytical expressions are derived for all types of semiconductor power losses present in these converters. The theoretical results were verified by means of numerical simulation performed in the PSIM simulation software. Its add-on module "Thermal module" was used to estimate semiconductor power losses using the datasheet parameters of the selected semiconductor devices. Results of calculations and simulation study were obtained for four operating points with different input voltage and constant input current to compare performance of the converters in renewable applications, like photovoltaic, where input voltage and power can vary significantly. Power loss breakdown is detailed and its dependence on the converter output power is analyzed. Recommendations are given for the use of the converter topologies in applications with low input voltage and relatively high input current.

Wide-Range Operation of High Step-Up DC-DC Converters with Multimode Rectifiers

“…Typically, the efficiency curve of a high step-up DC-DC converter with a BFEI reaches the maximum efficiency value at the maximum input voltage, which could be translated to D = 0 in each mode of the MMR. In Figure 5b, the maximum efficiency is achieved at D = 0, as the absence of the shoot-through states significantly decreases the rms currents of the switches due to the high current of the switches during the shoot-through states [26]. Moreover, the switching losses are minimum at D = 0, as the shoot-through states result in high switching currents of the main switches as well as reverse recovery losses in the synchronous switch S qZS [27,28].…”

Experimental study of high step-up quasi-Z-source DC-DC converter with synchronous rectification

“…The conduction power losses in the inverter MOSFETs (P Mcond ) contribute the last part to the semiconductor conduction power losses in the converter. They can be separated into two parts [6]:…”

“…It features a wide input voltage regulation range performed within a single stage, continuous input current, immunity to shoot-through and open states of the inverter bridge, low inrush current, high control flexibility, etc. However, all these advantages are achieved at the cost of higher number of passive components and Simulation study of the qZS DC-DC converter (qZSC) in [6] shows that conduction losses in semiconductors are the major cause of relatively low efficiency. Efficiency improvement through synchronous rectification was proposed and verified by help of simulation in [7].…”