scholarly journals Bidirectional Resonant DC-DC Converter for Microgrid applications

2020 ◽  
Vol 8 (5) ◽  
pp. 5338-5345

This paper presents a non-isolated bidirectional softswitching dc-dc converter for DC microgrid energy storage synchronization. To assist the soft switching of switches and diodes, the LCL resonant circuit is applied and an input end halfbridge boost converter is enforced. Using the voltage doubler circuit introduced on the output side, a voltage gain of 2X is achieved. Through the non-isolated circuit, the total voltage gain is obtained. The capacitive divider halves the voltage on the greater hand. The circuit performs a high frequency ripple of low output voltage. Diodes guarantee zero voltage Turn ON for switches and zero current turn ON and turn OFF during buck / boost operation Although no internal snubber circuits are available, the circuit ensures low voltage stress across semiconductor systems.

Author(s):  
Jaisudha S. ◽  
Sowmiya Srinivasan ◽  
Kanimozhi Gunasekaran

<p>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 LCC resonant tank to assist in soft-switching of switches and diodes, and finally a voltage doubler circuit at the output port to enhance the voltage gain by two times. The LCC resonant circuit also adds a suitable voltage gain to the converter. Therefore, overall high voltage gain of the converter is obtained without a transformer or large number of multiplier circuit. For operation in buck mode, the high side voltage is divided by half with capacitive divider to gain higher step-down ratio. The converter is operated at high frequency to obtain low output voltage ripple, 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 in both modes i.e., buck/boost operation. Voltage stress across switches and diode is clamped naturally without external snubber circuit. An experimental prototype has been designed, built and tested in the laboratory to verify the performance of the proposed converter.</p>


2020 ◽  
Vol 10 (22) ◽  
pp. 8250
Author(s):  
Bor-Ren Lin ◽  
Kun-Yi Chen

A new hybrid inductor-inductor-capacitor (LLC) converter is investigated to have wide voltage input operation capability and zero-voltage turn-on characteristics. The presented circuit topology can be applied for consumer power units without power factor correction or with long hold-up time requirement, photovoltaic energy conversion and renewable energy power transfer. To overcome the weakness of narrow voltage gain of resonant converter, the hybrid LLC converter with different turns ratio of transformer is presented and the experimental investigation is provided to achieve wide voltage input capability (400 V–50 V). On the input-side, the converter can operate as full bridge resonant circuit or half bridge resonant circuit with input split capacitors for high or low voltage input region. On the output-side, the less or more winding turns is selected to overcome wide voltage input operation. According to the circuit structures and transformer turns ratio, the single stage LLC converter with wide voltage input operation capability (400 V–50 V) is accomplished. The laboratory prototype has been developed and the experimental waveforms are measured and demonstrated to investigate the effectiveness of the presented hybrid LLC converter.


Author(s):  
C. M. de O. Stein ◽  
H. L. Hey ◽  
J. R. Pinheiro ◽  
H. Pinheiro ◽  
H. A. Gründling

This paper proposes a new auxiliary commutation cell for PWM inverters that allows the main switches to be turned on and off at zero voltage and zero current. The main switches zero current turn-on reduces the undesired effects of parasitic inductances related to the circuit layout. The main diodes reverse recovery losses are minimized since di/dt and dv/dt are controlled. The ZCZVT commutation cell is located out of the main power path of the converters and is activated only during switching transitions. Additionally, the auxiliary switches are turned on and off at ZCS and use the same ground signals of the upper main switches. The commutation losses are practically reduced to zero. Soft switching operation is guaranteed for full load range without changes in command strategy. The operation of the ZCZVT PWM full-bridge DC-AC Converter is analyzed and an auxiliary commutation cell design procedure based on the analysis is proposed. Experimental results are presented to demonstrate the feasibility of the proposed commutation cell.


Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1931
Author(s):  
Bor-Ren Lin ◽  
Yen-Chun Liu

A new circuit structure of LLC converter is studied and implemented to achieve wide zero-voltage switching range and wide voltage operation such as consumer power units without power factor correction and long hold up time demand, battery chargers, photovoltaic converters and renewable power electronic converters. The dc converter with the different secondary winding turns is adopted and investigated to achieve the wide input voltage operation (50–400 V). To meet wide voltage operation, the full bridge and half bridge dc/dc converters with different secondary turns can be selected in the presented circuit to have three different voltage gains. According to input voltage range, the variable frequency scheme is employed to have the variable voltage gain to overcome the wide input voltage operation. Therefore, the wide soft switching load variation and wide voltage operation range are achieved in the presented resonant circuit. The prototype circuit is built and tested and the experiments are demonstrated to investigate the circuit performance.


2013 ◽  
Vol 768 ◽  
pp. 388-391
Author(s):  
M. Santhosh Rani ◽  
Julie Samantaray ◽  
Subhransu Sekhar Dash

This paper presents a novel application of full-bridge series parallel resonant converter (FBSPRC) for dc source and secondary battery interface. Secondary batteries has been widely used in the application of residential, industrial and commercial energy storage systems because of its low energy conversion loss, which enhances the systems overall efficiency. A series parallel loaded resonant converter (SPRC) which is a subset of DC-DC converter can be operated with either zero-voltage turn-on (above resonant frequency) or zero current turn off (below resonant frequency) to eliminate the turn on and turn-off losses of the semiconductor devices. This converter is widely used to achieve reduction in size of the passive components of the converter such as inductor, capacitor and transformers. Simulation results based on a 12V 45Ah battery charger are proposed to validate the analysis and to demonstrate the performance of the proposed approach. Satisfactory performance is obtained from the measured results. The simulation results validate the effectiveness of the chosen battery charger.


2016 ◽  
Vol 25 (10) ◽  
pp. 1650128 ◽  
Author(s):  
Sevilay Cetin

This study presents an improved zero voltage switching (ZVS) boost converter with an active snubber cell providing soft switched operation for all semiconductors. The active snubber cell reduces the reverse recovery loss of the boost diode and also provides the zero voltage transition (ZVT) Turn-on and ZVS Turn-off for the boost switch. The zero current switching (ZCS) Turn-on and ZVS Turn-off for the snubber switch is also achieved. All diodes in the converter can be operated with soft switching (SS). In the snubber cell, SS energy can be transfered effectively to the output by the use of a snubber inductor and a capacitor. This energy transfer allows the use of additional parallel connected capacitor to the boost switch to provide ZVS turning off. There is no additional voltage and current stress on the boost switch and boost diode. The voltage stress of the snubber switch is also limited by the output voltage and the current stress of the snubber switch is reduced by the energy transfer to the output. SS operating of the semiconductors is maintained at very wide load ranges. The operation of the proposed converter is presented with a detailed steady state analysis. The predicted theoretical analysis is validated by a prototype with 500[Formula: see text]W output power and 100[Formula: see text]kHz operating frequency. The measured maximum efficiency values are obtained as approximately 97% and 85.4% at full load and 10% load conditions, respectively.


Author(s):  
M. L. Martins ◽  
H. Pinheiro ◽  
J. R. Pinheiro ◽  
H. A. Gründling ◽  
H. L. Hey

This paper presents a novel family of Zero Voltage Transition (ZVT) DC-DC PWM Converters that uses a resonant circuit as auxiliary commutation source to control the current through the auxiliary switch without additional current stresses on main devices. The improved ZVT commutation cell enables the main switch to be turned on and off at Zero Voltage Switching (ZVS) and the auxiliary switch to be turned on and off at Zero Current Switching (ZCS) from zero to full-load.


2014 ◽  
Vol 3 (3) ◽  
pp. 101-121 ◽  
Author(s):  
S. Aiswariya ◽  
R. Dhanasekaran

This paper proposes an AC-DC converter with the application of active type soft switching techniques. Boost converter with active snubber is used to achieve power factor correction. Boost converter main switch uses Zero Voltage Transition switching for turn on and Zero Current Transition switching for turn off. The active snubber auxillary switch uses Zero Current Switching for both turn on and turn off. Since all the switches of the proposed circuit are soft switched, overall component stress has been greatly reduced and the output DC voltage is expected to have low ripples. A small amount of auxillary switch current is made to flow to the output side by the help of coupling inductor. The proposed circuit is simulated using MATLAB Simulink. All the related waveforms are shown for the reference. The power factor is measured as 0.99 showing that the input current and input voltage is in phase with each other. The PFC circuit has very less number of components with smaller size and can be controlled easily at a wide line and load range.


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