Viktor Beldjajev

Analysis of current doubler rectifier based high frequency isolation stage for intelligent transformer

This paper proposes new topology for high frequency isolation stage of intelligent transformer based on bi-directional current doubler rectifier (CDR). Paper provides complete steady-state analysis of the proposed bi-directional CDR in boost mode. To facilitate the understanding of operation, the converter equivalent circuits for each operating mode with corresponding waveforms are presented. Also, mathematical analysis is done and compared with simulation results.

Impact of component losses on the efficiency of the LC-filter based dual active bridge for the isolation stage of power electronic transformer

This paper presents a steady state analysis of the commutating LC-filter based dual active bridge (DAB) considering the conduction losses in the components. The aim is to use this converter in power electronic transformer (PET). The LC-filter offers the boost properties with a small component count and DAB allows effective power flow control and soft switching capabilities. Such combination allows the voltage on the transformer terminals to be kept at the desired level to enable the best performance of the converter. In order to facilitate the impact of the losses on the power characteristics and efficiency the mathematical loss models are derived and experimental results are presented.

Isolation stage for power electronic transformer: Dual active bridge vs bi-directional current doubler rectifier

This paper compares two DC/DC converter topologies which are suitable for isolation stage of power electronic transformer. Paper provides loss analysis of dual active bridge and current doubler rectifier topologies in forward and reverse operating modes. In particular, the conduction and switching losses, as well as overall efficiency are estimated. In addition, the calculated losses and overall efficiency of both converters are verified with simulations and with experimental results on 1 kW experimental prototype.

Impact of Component Losses on the Efficiency of a New Quasi-Z-Source-Based Dual Active Bridge

The paper analyzes the impact of the component losses on the efficiency of the novel DC/DC converter. The converter is a combination of the quazi-Z-source (qZS) network and dual active bridge (DAB). In the analysis the mathematical loss models of the proposed DC/DC converter are derived and efficiency is estimated. Eventually the efficiency is verified experimentally.

Techno-economic analysis of hydrogen buffers for distributed energy systems

Massive utilization of fossil fuels presents serious environmental threats. In this context, today the development of renewable energies is an urgent issue. Due to the stochastic nature of renewable energy sources an energy storage is needed in renewable energy generation systems. Hydrogen-based energy storage system or hydrogen buffer can help to stabilize unregulated renewable energy generation. In the hydrogen buffer system, the excess wind energy is stored in the form of hydrogen via conversion through the electrolyzer. The fuel cell is used to produce electrical power when the load demand exceeds that produced by the renewable energy sources. Hydrogen buffer includes two main operational stages: electrochemical and power electrical. This paper explores the techno-economic analysis of the electrochemical stage of the hydrogen buffer in order to increase the efficiency of hydrogen production in the renewable energy system.

Impact of component losses on the efficiency of the bi-directional current doubler rectifier based isolation-stage

This paper presents a detailed analysis of the bi-directional current doubler rectifier (CDR) that is a good candidate for use in a power electronic transformer (PET). Among various advantages the current doubler rectifier offers a bi-directional power flow capability that is the major requirement for the PET. This paper provides the steady state analysis of the CDR in the bi-directional operation. In addition, the impact of the component losses on the efficiency is analyzed. Finally a suitable snubber circuit is proposed to damp the voltage peaks.