Luan C. S. Mazza

A soft switching bidirectional DC-DC converter with high frequency isolation

In this paper, a three-port soft switching DC-DC converter based on the bidirectional version of the three-state switching cell (3SSC) and dual active bridge (DAB). The converter features high voltage gain and current reduced stress in the converter primary switches. The soft switching curves are presented, showing that all active switches are designed to operate in Zero Voltage Switching (ZVS), depending on the phase shift and amplitude of the voltage in the primary and secondary winding. The analysis of the model fundamental and experimental results a 2 kW, port 1 (48 V) and port 3 (311 V) prototype are presented. The experimental results are presented in two modes: Mode Discharge Battery Bank (MDBB) and Mode Charge Battery Bank (MDBB). The maximum efficiency in MDBB is 96% and in MCBB is 95.5%.

Bidirectional converter with high frequency isolation feasible to solid state transformer applications

This paper presents a new three-port ac-dc converter topology based on the bidirectional version of the three-state switching cell (3SSC) and neutral point clamped (NPC) with Dual Active Bridge (DAB) feasible to interconnect an AC link, a DC link and photovoltaic panels. The three port converter operates as solid state transformer (SST). It the primary side switches voltage and current stresses are reduced due to NPC and 3SSC characteristics. Some operating ranges presented Zero Voltage Switching (ZVS). Modulation strategy and control are presented. For the drive control was implemented five control loops: PFC (Power Factor Correction); full voltage and balancing voltages acroos port 2 capacitors; magnetization current and voltage on port 3. A 33.33 kW converter with the peak value of the AC voltage is 9.35 kV and DC voltage at port 3 is 800 V with a DC bus voltage at port 2 of 22 kV has been simulated. A comparative loss studies with other converter topologies is also made. The proposed topology presented efficiency of 97.2%.

Microinverter single phase derived of flyback topology for generating system photovoltaic

This paper proposes develop the implementation of a single-stage single-phase shunt microinverter obtaining four DC-DC converters operating in discontinuous flybacks mode and associated modules in parallel. To validate the experimental research will develop a prototype that will effect the processing power connects a photovoltaic panel with 200 W of power in resistive loads with sinusoidal characteristics. The results obtained in the laboratory show that the microinversor flyback operating in open loop obtains yields close to 90%, being delivered to the load about 180 W. Thus, the ease in construction, using fewer components and enable the experimentally obtained microinversor flyback to perform the DC-AC conversion of photovoltaic systems of small powers connected in single-phase linear loads or connected to the grid.

Five-level T-type NPC PFC rectifier based on multistate switching cell

This paper presents a proof of concept of a new converter cell named T-type multistate switching cell (TT-MSSC). The proposed cell was derived from the three-phase current fed DC-DC Push-Pull converter with NPC output rectifier and can provide both AC-DC and DC-AC conversions for single-phase, three-phase or multi-phase configurations. Based on the proposed cell, a single-phase unidirectional converter is proposed which provides the following features: power factor correction, current sharing through devices, symmetrical voltage division across semiconductors, inductor current ripple with twice switching frequency, and five level voltage formation between ground point and common point of the autotransformer. To verify the operation principle, a prototype with the input voltage Vi = 220 V (rms), output voltage Vo = 800 V, and output power Po = 1 kW was implemented and tested in laboratory.

A soft switching bidirectional DC-DC converter based on three-state switching cell to photovoltaic systems applications

This paper presents a new three-port soft switching dc-dc converter topology based on the bidirectional version of the three-state switching cell, feasible to interconnect battery banks with a dc link and photovoltaic panels. All active switches are designed to operate in Zero Voltage Switching (ZVS). The theoretical analysis and experimental results a 2 kW prototype are presented.