Query: bidirectional non isolated resonant  dc-dc converter

Candidate papers:

abstract: This paper proposes a current fed non isolated soft switching bidirectional dc/dc converter for interfacing energy storage to dc microgrid. The proposed converter employs a current fed half bridge boost converter at front end followed by an LCL resonant circuit to aid in soft switching of semiconductor devices. A voltage doubler at output is selected to enhance the gain by 2x. The LCL resonant circuit also adds a suitable voltage gain. Therefore, the topology offers overall high voltage gain without transformer or large number of multiplier circuits. For buck operation, high side voltage is first divided by half with capacitor divider to gain higher stepdown ratio. Converter operates at high switching frequency to realize merits of reduced magnetics and filters. Zero voltage turn on is achieved for all switches and zero current turn on and turn off is achieved for all diodes for both buck/boost operation. Voltage across switches and diode is clamped naturally without any external snubber circuit. Detailed analysis and design have been proposed. A proof of concept experimental prototype rated at 350 W has been designed, developed, and tested in the laboratory to demonstrate the performance and validate the claims of the converter for wide load variation.
author_names: Akshay Kumar Rathore

Devendra Patil

Dipti Srinivasan
title: Non isolated Bidirectional Soft Switching Current Fed LCL Resonant DC/DC Converter to Interface Energy Storage in DC Microgrid
venue: IEEE Transactions on Industry Applications
year: 2016

abstract: This paper proposes a non isolated soft switching bidirectional dc/dc converter for interfacing energy storage in DC microgrid. The proposed converter employs a half bridge boost converter at input port followed by a LCL resonant circuit to assist in soft switching of switches and diodes, and finally a voltage doubler circuit at output port to enhance the voltage gain by 2x. The LCL resonant circuit may also add a suitable voltage gain to the converter. Therefore, overall high voltage gain of the converter is obtained without transformer or large number of multiplier circuit. For buck operation, the high side voltage is first divided by half with capacitive divider to gain higher step down ratio. Converter is operated at high frequency to obtain low output voltage ripple and reduced magnetics and filters. Zero voltage turn on is achieved for all switches and zero current turnon and turn off is achieved for all diodes for both buck/boost operation. Voltage stress across switches and diode is clamped naturally without external snubber circuit. An experimental prototype rated at 350 W has been designed, built and tested in the laboratory to verify the analysis, design and demonstrate the performance of proposed converter.
author_names: Devendra Patil

Akshay Kumar Rathore

Dipti Srinivasan
title: A non isolated bidirectional soft switching current fed LCL resonant dc/dc converter to interface energy storage in DC microgrid
venue: 2015 IEEE Applied Power Electronics Conference and Exposition (APEC)
year: 2015

abstract: Isolated converters are desirable in the DC DC power conversion applications where isolation and/or a large voltage step up gain is needed. Traditional isolated DC DC converters either utilize many switches to achieve high efficiency or use few switches which result in low efficiency. This paper proposes a current fed non isolated soft switching bidirectional dc/dc converter for interfacing energy storage to dc microgrid. The proposed converter employs a current fed half bridge boost converter at front end followed by an LCL resonant circuit to aid in soft switching of semiconduc tor devices. The proposed isolated DC DC converter has the advantages of not only using the least number of switches, but also achieving zero current switching (ZCS) and zero voltage switching (ZVS) when the switch is turned on and off, respectively. The LCL resonant circuit also adds a suitable voltage gain. Simulational results are provided to validate the theoretical analysis and simulation. The proposed converter has achieved the maximum efficiency of 93.5% which is higher than the corresponding hard switching converter with a similar topology.
author_names: T R Jyothsna

A Ravi Kumar

D Prasada Rao
title: A New Solar PV MPPT based Non Isolated Bidirectional Current Fed Resonant DC DC Converter
year: 2017

abstract: ABSTRACT This paper presents a dual inductor based current fed bidirectional non isolated DC DC converter for energy storage applications. The main idea of this converter is to achieve a higher voltage conversion ratio by obtaining the operation of zero current switching. The proposed soft switching bidirectional DC DC converter reduces the turn off switching losses with the aid of auxiliary network, where, the auxiliary network comprised with the resonant inductor and the resonant capacitor. This converter operates under two different operating modes such as a boost (discharge) and buck (charge) modes. In both the modes of converter operations, the IGBTs are operating under zero current turn off in order to minimize the switch turn off losses and to improve the efficiency of the converter. The principle of the operations and its theoretical analysis are validated by the experimental results using a 300W (50 V/250 V) converter system.
author_names: V V Subrahmanya Kumar Bhajana

Pavel Drabek

Rajesh Thumma
title: Analysis and design of a high gain non isolated zero current switching bidirectional DC DC converter for electric vehicles
year: 2019

abstract: This paper deals with a new high voltage gain zero current switching bidirectional DC DC converter for electric vehicles. The hard switched non isolated bidirectional converter integrated with auxiliary active switches and resonant elements were designed to attain the zero current switching turn off operation in the main IGBTs. This converter has dual characteristics as battery charge (buck) mode and discharge (boost) mode. By individual mode, all the active switches operate under zero current switching turn off operation for the minimized turn off losses. The proposed converter has high voltage gain with reduced turn off losses when operating in discharge mode and has low output voltage conversion in charge mode. The topology described with the aid of theoretical waveforms were tested using a laboratory prototype 70/300 V, 800 W system functioned under 50 kHz operating frequency.
author_names: Rajesh Thumma

V V Subrahmanya Kumar Bhajana

Pavel Drabek

Martin Jara
title: A New High Voltage Gain Non Isolated Zero Current Switching Bidirectional DC DC Converter
year: 2018

abstract: This paper details efficiency optimized operation and design of a bi directional and isolated five level Dual Active Bridge (5LDAB) converter for an application that requires ultra wide voltage and power ranges. The rated power of the considered converter is 7.5kW, the specified input voltage range is 150V Vdc1 800V and the output voltage is constant, Vdc2 700V. In order to achieve high efficiency levels in a wide operating range, a modulation scheme is proposed to minimize the transformer rms current. Results of transformer rms currents and of efficiencies are presented for the 5LDAB and compared with the results obtained for an efficiency optimized conventional Dual Active Bridge (DAB) converter. Compared with the DAB topology, the 5LDAB converter can achieve an overall reduction of transformer rms currents and of conduction losses in the higher voltage regime of the operating range.
author_names: Pedro A M Bezerra

Florian Krismer

Ralph M Burkart

Johann Walter Kolar
title: Bidirectional isolated non resonant DAB DC DC converter for ultra wide input voltage range applications
venue: 2014 International Power Electronics and Application Conference and Exposition
year: 2014

abstract: Abstract This paper proposes a non isolated high step up multi input DC DC converter for utilizing in hybrid applications. This converter provides the interfaces between input power sources, energy storage devices and load. The resonant auxiliary circuit used in the proposed converter provides soft switching condition for the main switches as well as charging the storage device which has caused considerable improvement in the converter efficiency. This converter uses only three switches to control the power absorbed from a unidirectional input, the power absorbed or stored in the bidirectional port and also the power transmitted to load while provides soft switching condition of all semiconductor devices. Thus, the number of switches applied is same as conventional hard switched converters for this purpose. This converter shares only one inductor between all inputs, so the volume is reduced. Various converter operating modes are discussed and design considerations are presented. Finally, to validate the theoretical analysis, a prototype of the proposed converter is implemented for a 400 V output voltage at 200 W.
author_names: Rasoul Faraji

Ehsan Adib

Hosein Farzanehfard
title: Soft switched non isolated high step up multi port DC DC converter for hybrid energy system with minimum number of switches
venue: International Journal of Electrical Power Energy Systems
year: 2019

abstract: The output of solar PV and battery is in the form of DC. Feeding of load from these sources requires conversion from dc to ac or dc to dc. DC microgrids popular for this feature in distributed generation on distribution systems. Energy storage in microgrid ensures electrical saving during no load or off load microgrid. To ensure power flow between DC microgrid and energy storage devices bidirectional dc dc converter is required. The minimization of losses in dc dc converter is a big task to improve efficiency. This paper proposes a non isolated bi directional DC/DC converter for interfacing DC voltage with energy storage in DC microgrid. The proposed converter is combination of current fed half bridge boost converter and LCL resonant circuit for soft switching. Boost operation gained by 8 times with the help of front end boost converter, LCL resonant tank and doubler. For buck operation, high side voltage is divided by half with capacitor divider and front end converter further clamp the voltage. In this paper, the detailed analysis and design is proposed for bidirectional dc dc converter is done. Soft switching is also implemented by ZVS turn ON of switches and ZCS turn ON/OFF to diode. The performance analysis of proposed converter is done bidirectional power flow with soft switching in MATLAB/Simulink environment.
author_names: Pavan Singh Tomar

Ashok Sharma

Kanak Hada
title: Energy storage in DC microgrid system using non isolated bidirectional soft switching DC/DC converter
venue: 2017 6th International Conference on Computer Applications In Electrical Engineering Recent Advances (CERA)
year: 2017

abstract: A new soft switched, 5 switch string structured bidirectional DC/DC converter with an isolated CLLC resonant circuit is presented in this paper for energy storage applications. In the proposed circuit, only one switch and two diodes are added to the conventional 4 switch string structured converter enabling the converter to operate in rectifying mode with lower output voltage ripples and higher efficiency. A CLLC resonant circuit is designed to allow stepping up or stepping down the voltage to desired value with the same operating frequency in both boost and buck modes with variable frequency control. All the switches and diodes are able to achieve soft switching to enhance the circuit efficiency. Simulation results are given on a 1kW, 100VDC/300VDC system to highlight the merits of the proposed converter. Preliminary experimental results are also provided on a laboratory scale 100/300VDC prototype to further support the features of this work.
author_names: Reza Emamalipour

John Chi Wo Lam
title: A new non multi level structured, H bridgeless DC/DC bidirectional converter with low voltage stress and complete soft switching operation
venue: 2019 IEEE Applied Power Electronics Conference and Exposition (APEC)
year: 2019

abstract: This paper proposes a switched capacitor based non isolated zero voltage switching (ZVS) bi directional dc dc converter. By implementing a switched capacitor loop, it can provide high step up and step down gain. The converter is operated in continuous current mode (CCM) mode where all the power transistors are soft switched by means of dedicated auxiliary resonant networks. Each network consists of a low rated power switch (with a body diode) a resonant capacitor and a resonant inductor. The resonant capacitors are further optimized for zero voltage switching (ZVS) turn off of the power switches. The ZVS turn on and turn off conditions are achieved for all power switches in the boost and buck mode of operations. In addition, the voltage and current stresses on the power switches are significantly reduced, thus enhancing the converter operation at high power applications.
author_names: Ratil Hasnat Ashique

Zainal Salam

M J Aziz
title: A high gain soft switching non isolated bidirectional DC DC converter
venue: 2016 IEEE International Conference on Power and Energy (PECon)
year: 2016