A Comparison of Non-Isolated High-Gain Three-Port Converters for Hybrid Energy Storage Systems

Abstract

This work carries out a comparison of non-isolated topologies for power electronic converters applied to Hybrid Energy Storage Systems. At the considered application, several options for three-port circuits are evaluated when interfacing a DC link with two distinct electrical energy storage units. This work demonstrates how the proposed structure, referred to as Series-Parallel Connection, performs as a simple, compact and reliable approach, based on a modification of the H-bridge configuration. The main advantage of this solution is that an effective large voltage gain at one of the ports is attained by means of a simple topology, preventing the use of multilevel or galvanic-isolated power stages. The resulting structure is thoroughly compared against the most significant direct alternatives. The analysis carried out on the switching and conduction losses in the power switches of the target solution states the design constraints at which this solution shows a performance improvement. The experimental validations carried out on a 10 kW prototype demonstrate the feasibility of the proposed scheme, stating its benefits as well as its main limitations. As a conclusion, the Series-Parallel Connection shows a better performance in terms of efficiency, reliability and controllability in the target application of compensating grid or load variations in Non-Isolated Hybrid Storage Systems, with large mismatch in the storage device voltage ratings.

A critical review on contemporary power electronics interface topologies to vehicle‐to‐grid technology: Prospects, challenges, and directions

“…Also, galvanic isolation is a big problem in this topology. Therefore, non‐isolated topologies might be restricted to low‐medium voltage ratios [84]. Isolated topologies provide improved safety due to the presence of isolation HFT, which increases the weight, footprint, and expense of the framework with the level of insulation [85].…”

A Nonisolated Three-Port DC–DC Converter with Continuous Input and Output Currents Based on Cuk Topology for PV/Fuel Cell Applications

“…From (10), one can understand that the proposed converter operating in DISO mode has the same voltage gain compared with classical Cuk converter, which is plotted in Figure 8. Considering V 1 = V 2 = V, the output voltage of the proposed converter is presented in (11). Selecting the same duty ratio for both the switches leads to the output voltage equal to the one in classical Cuk converter as derived in (12).…”

“…The isolated TPC uses a transformer with a high-frequency to provide magnetic coupling and electrical isolation between the source and load [6][7][8]; partially isolated converters use a common DC bus along with magnetic coupling [9]. A nonisolated TPC uses common DC bus and finds applications where the isolation is not needed between the ports [10][11][12]. TPCs can be configured in two topologies based on the nature of the input sources: series and parallel.…”

A Distributed Control Strategy for Islanded Single-Phase Microgrids with Hybrid Energy Storage Systems Based on Power Line Signaling

“…Several strategies can be used to split the power share between the SESS and the BESS of the hybrid system. In DC MGs, the most simple way is to obtain the power reference of the batteries by applying a lowpass filter to the overall power reference as shown in (3) [36,37]. In AC MGs, this step is not as straightforward, as discussed in following sections.…”