scholarly journals Voltage Balance Switching Scheme for Series-Connected SiC MOSFET LLC Resonant Converter

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 4003 ◽  
Author(s):  
Cha ◽  
Kim
Keyword(s):  
High Efficiency ◽  
Field Effect Transistors ◽  
Input Voltage ◽  
Oxide Semiconductor ◽  
System Stability ◽  
Resonant Converter ◽  
Switching Scheme ◽  
Zero Voltage Switching ◽  
Voltage Balance ◽  
Llc Resonant Converter

To achieve high efficiency and power density, silicon carbide (SiC)-based Inductor-Inductor-Capacitor (LLC) resonant converters are applied to the DC/DC converter stage of a solid-state transformer (SST). However, because the input voltage of an SST is higher than the rated voltage of a commercial SiC device, it is essential to connect SiC devices in series. This structure is advantageous in terms of voltage rating, but a parasitic capacitance tolerance between series-connected SiC devices causes voltage imbalance. Such imbalance greatly reduces system stability as it causes overvoltage breakdown of SiC device. Therefore, this paper proposes a switching scheme to solve the voltage imbalance between SiC metal-oxide-semiconductor field-effect transistors (MOSFETs). The proposed scheme sequentially turns off series-connected SiC MOSFETs to compensate for the turn-off delays caused by parasitic capacitor tolerances. In addition, dead-time selection methods to achieve voltage balance and zero voltage switching simultaneously are provided in detail. To verify the effectiveness of the proposed scheme, experiments were conducted on a 2 kW series-connected SiC MOSFET LLC resonant converter prototype.

Design and Implementation of LLC Resonant Converter for Photovoltaic Battery Charging Application

2015 ◽  
Vol 785 ◽  
pp. 101-105
Author(s):  
Adrian Soon Theam Tan ◽  
Shahid Iqbal
Keyword(s):  
High Efficiency ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Photovoltaic System ◽  
Resonant Converter ◽  
Battery Charging ◽  
Zero Voltage Switching ◽  
Design And Implementation ◽  
Switching Losses ◽  
Llc Resonant Converter

Photovoltaic power conditioning system (PVPCS) requires a high efficiency dc-dc converterstage capable of wide input voltage regulation and have the ease of maximum power point implementation for both stand alone photovoltaic system and grid-connected system. Galvanic isolation at the dc-dc stage can replace the isolation needed in the inverter stage and thus reduce the sizeof isolation transformer and increases overall system efficiency. This paper presents detailed analysis,design and implementation of a LLC resonant converter for photovoltaic battery charging application.The LLC resonant converter operate with zero voltage switching (ZVS) turn on and low current turnoff thus reducing switching losses. The experimental results are given to validate the operation andperformance of the converter.

scholarly journals Wide Voltage Resonant Converter Using a Variable Winding Turns Ratio

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 370 ◽  
Author(s):  
Bor-Ren Lin ◽  
Chu-Xian Dai
Keyword(s):  
Low Voltage ◽  
Field Effect Transistors ◽  
Oxide Semiconductor ◽  
Resonant Circuit ◽  
Frequency Variation ◽  
Switching Frequency ◽  
Voltage Gain ◽  
Resonant Converter ◽  
Voltage Range ◽  
Llc Resonant Converter

This paper presents a inductor–inductor–capacitor (LLC) resonant converter with variable winding turns to achieve wide voltage operation (100–400 V) and realize soft switching operation over the entire load range. Resonant converters have been developed for consumer power units in computers, power servers, medical equipment, and adaptors due to the advantages of less switching loss and better circuit efficiency. The main disadvantages of the LLC resonant converter are narrow voltage range operation owing to wide switching frequency variation and limited voltage gain. For computer power supplies with hold-up time function, electric vehicle battery chargers, and for power conversion in solar panels, wide input voltage or wide output voltage operation capability is normally demanded for powered electronics. To meet these requirements, the variable winding turns are used in the presented circuit to achieve high- or low-voltage gain when Vin is at low- or high-voltage, respectively. Therefore, the wide voltage operation capability can be implemented in the presented resonant circuit. The variable winding turns are controlled by an alternating current (AC) power switch with two back-to-back metal-oxide-semiconductor field-effect transistors (MOSFETs). A 500-W prototype is implemented and test results are presented to confirm the converter performance.

scholarly journals Comparative Performance and Assessment Study of a Current-Fed DC-DC Resonant Converter Combining Si, SiC, and GaN-Based Power Semiconductor Devices

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1982
Author(s):  
Oscar Miguel Rodríguez-Benítez ◽  
Mario Ponce-Silva ◽  
Juan Antonio Aquí-Tapia ◽  
Abraham Claudio-Sánchez ◽  
Luis Gerardo Vela-Váldes ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Input Voltage ◽  
Oxide Semiconductor ◽  
Switching Frequency ◽  
Resonant Converter ◽  
Comparative Performance ◽  
Voltage Range ◽  
Power Semiconductor ◽  
Low Efficiency ◽  
A Current

This paper focuses on the main reasons of low efficiency in a current-fed DC-DC resonant converter applied to photovoltaic (PV) isolated systems, comparing the effects derived by the overlapping time in the gate-signals (gate-source voltage) combining silicon (Si), silicon carbide (SiC), and gallium nitride (GaN)-based power devices. The results show that unidirectional switches (metal–oxide–semiconductor field-effect transistors (MOSFETs) plus diode) present hard switching as a result of the diode preventing the MOSFET capacitance of being discharged. The effectiveness of the converter was verified with a 200-W prototype with an input voltage range of 0–30.3 V, an output voltage of 200 V, and a switching frequency of 200 kHz. The reduction losses by applying GaN versus Si and SiC technologies are 66.49% and 53.57%, respectively. Alternatively, by applying SiC versus Si devices the reduction loss is 27.84%. Finally, according to the results, 60% of losses were caused by the diodes on both switches.

scholarly journals Analysis of a Wide Voltage Hybrid Soft Switching Converter

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 473 ◽  
Author(s):  
Bor-Ren Lin ◽  
Yen-Chun Liu
Keyword(s):  
Power Conversion ◽  
Input Voltage ◽  
Soft Switching ◽  
Resonant Converter ◽  
Solar Pv ◽  
Load Range ◽  
Pwm Converter ◽  
Load Voltage ◽  
Zero Voltage Switching ◽  
Circulating Current

A hybrid PWM converter is proposed and investigated to realize the benefits of wide zero-voltage switching (ZVS) operation, wide voltage input operation, and low circulating current for direct current (DC) wind power conversion and solar PV power conversion applications. Compared to the drawbacks of high freewheeling current and hard switching operation of active devices at the lagging-leg of conventional full bridge PWM converter, a three-leg PWM converter is studied to have wide input-voltage operation (120–600 V). For low input-voltage condition (120–270 V), two-leg full bridge converter with lower transformer turns ratio is activated to control load voltage. For high input-voltage case (270–600 V), PWM converter with higher transformer turns ratio is operated to regulate load voltage. The LLC resonant converter is connecting to the lagging-leg switches in order to achieve wide load range of soft switching turn-on operation. The high conduction losses at the freewheeling state on conventional full bridge converter are overcome by connecting the output voltage of resonant converter to the output rectified terminal of full bridge converter. Hence, a 5:1 (600–120 V) hybrid converter is realized to have less circulating current loss, wide input-voltage operation and wide soft switching characteristics. An 800 W prototype is set up and tested to validate the converter effectiveness.

Sign in / Sign up

Export Citation Format

Share Document