Ali M. S. Al-bayati

A high-performance non-isolated DC-DC buck converter design based on wide bandgap power devices

Due to the limitations in the operating conditions of the conventional silicon (Si) power device based dc-dc buck converters as well as its notable power losses, there is an increased interest and need to exploit the promising features of wide bandgap power devices toward more efficient converters. This paper presents the design of an efficient, high performance and reliable non-isolated dc-dc buck converter based on silicon carbide (SiC) power devices. First, the converter is designed using the SiC-MOSFET/SiC-Schottky diode power devices and it is compared with the CoolMOS/Si-diode based converter. A comprehensive study is done in terms of high switching frequency capabilities, different junction temperatures, as well as with a wide range of output load currents. The results show that a substantial and advanced amelioration in the efflciency for the designed SiC-MOSFET/SiC-Schottky diode based converter at operating conditions that include high switching frequencies, high junction temperatures, as well as at high and low output load currents.

Design and performance study of a DC–DC ZETA converter with wide bandgap power devices

The rapid growth in renewable energy based electric power generation continuously pushes for the need of high performance power conversion systems. This paper mainly focuses on the design and performance study of a DC– DC ZETA converter using wide bandgap power devices. The converter is designed based on a SiC MOSFET/SiC Schottky diode, and its performance is compared with a Si IGBT/SiC Schottky diode based converter. The switching characteristics of the SiC MOSFET and Si IGBT power devices within the converter are studied and compared. A comprehensive evaluation of the total power loss and overall efficiency of the converter is analyzed and reported. The results indicate that the converter with the SiC MOSFET/SiC Schottky diode has great potential to work efficiently under different operating conditions.

Investigation of an interleaved high-gain DC-DC converter with GaN power semiconductor devices for DC-distributed renewable energy systems

The negative environmental impacts of energy production from gas and fossil fuels are causing widespread concern to developed countries. However, electricity production from wind turbines and solar energy systems is evolving rapidly to meet the demand for clean and renewable energy. Integrating renewable energy sources with power conversion systems is an area of intense research. Among possible alternative energy resources, solar photovoltaic (PV) systems are increasingly used for electric power generation because they are eco-friendly, emission-free, and relatively cost-effective. High-gain converters are an essential component utilized mainly in low-voltage renewable energy sources and dc-distribution systems because they provide a high-voltage gain and are more efficient than other step-up converters. Interleaved high-gain dc-dc converters promise efficient energy conversion across a range of applications, including distributed generation and grid integration. This paper presents a performance analysis of an interleaved high-gain dc-dc converter for dc-distributed renewable energy systems with 650 V GaN HEMTs. The converter design with GaN power transistors and SiC Schottky diodes is discussed. The performance of the high-gain converter is examined at different input voltages and output power levels.

Impact of cascode GaN power devices on a bidirectional DC-DC buck/boost converter in DC Microgrids

DC microgrids are gaining significant attention for smart distributed power systems, particularly in commer- cial and residential sectors, because of their increased energy efficiency, improved power quality, and reduced generation cost. In DC microgrids, distributed renewable energy sources, such as wind turbines, photovoltaic (PV) arrays, and fuel cells, along with energy storage systems–batteries and ultracapacitors–are increasingly implemented as a method of sustainable and clean power generation. Power electronic converters, especially bidirectional buck/boost topologies, play a major role in interfacing these renewable energy sources and energy storage systems with the utility network. However, most existing bidirectional converters face serious conduction and switching losses caused by conventional silicon (Si) devices, which are reaching their theoretical and oper- ational limits. Wide bandgap (WBG) semiconductor devices, such as silicon carbide (SiC) and gallium nitride (GaN), are not only exceed the current Si devices’ limitations but also provide great potential for improving power converters. This paper presents the impact of cascode GaN power devices on a bidirectional DC–DC buck/boost converter in DC microgrids. The results reveal that cascode GaN power devices considerably im- prove the converter performance and efficiency at various switching frequencies, junction temperatures, and output power levels.

Design and performance evaluation of a DC-DC buck-boost converter with cascode GaN FET, SiC JFET, and Si IGBT power devices

Wide bandgap (WBG) semiconductors exhibit superior material properties, enabling power devices to operate at higher blocking voltages, switching frequencies, and junction temperatures. Power converters featuring WBG devices have higher power density and are more efficient and reliable than those using existing silicon (Si) devices. This paper presents the design of a non-isolated dc-dc buck-boost converter and evaluates the impacts of three power devices on converter performance. To evaluate overall performance, three buck-boost converters are designed and tested: one with a Cascode GaN FET, one with a SiC JFET, and one with a Si IGBT. Additionally, a SiC Schottky diode is implemented in each converter to reduce switching energy loss of power devices and improve converter performance. The switching behavior and energy loss of three power devices are evaluated at various junction temperatures. Total power loss and efficiency of each converter are compared at different switching frequencies, output power levels, and operating temperatures. The results show that the Cascode GaN FET-based converter yields considerable improvements in switching performance, total power loss, and overall efficiency.

A comparative performance evaluation of Si IGBT, SiC JFET, and SiC MOSFET power devices for a non-isolated DC-DC boost converter

Power semiconductor devices made with wide-bandgap (WBG) materials such as Silicon Carbide (SiC) are improving the energy conversion efficiency, power density, and switching performance of converters. This paper presents a comparative performance evaluation of Si IGBT, SiC JFET, and SiC MOSFET power devices implemented in an otherwise identical, non-isolated dc-dc boost converter. Switching characteristics and energy loss are used to compare the performance of the three different devices. Overall converter performance is evaluated by measuring the total power loss and efficiency at different switching frequencies, load currents, and output power levels. The results show that the SiC MOSFET and SiC JFET perform better in the converter than the Si IGBT because of their lower on-state resistance and switching energy loss. The SiC power devices in the converter reduce total power loss due to their better switching performance at higher frequencies. The SiC converters are more efficient at increasing load currents and output power levels.

A comparative design and performance study of a non-isolated DC-DC buck converter based on Si-MOSFET/Si-Diode, SiC-JFET/SiC-schottky diode, and GaN-transistor/SiC-Schottky diode power devices

Conventional silicon (Si) based power devices are commonly used in industrial battery charging applications. In most cases, fast switching operation is desired in such applications in order to have a compact power converter system in terms of size and weight, while in contrast, it drives for large switching losses. The maturity of wide bandgap (WBG) technology provides enormous opportunities to ameliorate fast switching capabilities, high blocking voltage abilities, and high temperature operating conditions for power devices. This paper presents a comparative design and performance study of a non-isolated dc-dc buck converter based on three combinations of power devices: Si-MOSFET/Si-diode, SiC-JFET/SiC-Schottky diode, and GaN-transistor/SiC-Schottky diode for industrial applications. Characterization of the switching behavior of each power device and evaluation of switching energy losses are presented and discussed. Furthermore, the overall converter efficiency at high switching operations as well as with a wide operating range of input voltages, and the converter power density to size ratio are studied and reported. Results are shown that the GaN-transistor/SiC-Schottky diode and SiC-JFET/SiC-Schottky diode based converters exhibit significant lower switching energy losses and less total converter power loss, and thus a more efficient performance compared to the Si-MOSFET/Si-diode based converter. Through the analysis performed, it is shown that the hybrid combination of the GaN-transistor/SiC-Schottky diode followed by the SiC-JFET/SiC-Schottky diode combination are the most robust options for a high performance, high power density with smaller size non-isolated dc-dc buck converter for harsh operating conditions.

Design of a high-performance cascaded boost converter with SiC power devices for photovoltaic applications

This paper presents a positive output cascaded boost converter design based on wide bandgap power devices for photovoltaic (PV) applications. The objective is to enhance the converter’s performance and efficiency. The converter with SiC MOSFET devices is discussed and compared to a conventional cascaded boost converter based on Silicon (Si) devices. A 205 W cascaded boost converter with an input voltage of 26.6 V and an output voltage of 400 V is simulated to examine the switching behavior and energy loss of each power device. Converter performance with these two power devices is analyzed in terms of total power loss and efficiency at high switching frequencies and loading conditions. SiC power devices in the cascaded converter set-up perform better with minimized switching loss under a wide range of switching frequency conditions. The results show that the cascaded converter with SiC devices significantly reduces total power loss and improves the overall efficiency.

Design and performance study of a DC-DC flyback converter based on wide bandgap power devices for photovoltaic applications

This paper presents a high-performance dc–dc flyback converter design based on wide bandgap (WBG) semiconductor devices for photovoltaic (PV) applications. Two different power devices, a gallium nitride (GaN)-transistor and a silicon (Si)-MOSFET, are implemented individually in the flyback converter to examine their impact on converter performance. The total power loss of the converter with different power devices is analyzed for various switching frequencies. Converter efficiency is evaluated at different switching frequencies, input voltages, and output power levels. The results reveal that the converter with the GaN-transistor has lower total power loss and better efficiency compared to the converter with the conventional Si-MOSFET.

Development of an efficient DC-DC SEPIC converter using wide bandgap power devices for high step-up applications

A highly efficient high step–up dc–dc converter is the major requirement in the integration of low voltage renewable energy sources, such as photovoltaic panel module and fuel cell stacks, with a load or utility. This paper presents the development of an efficient dc–dc single–ended primary–inductor converter (SEPIC) for high step–up applications. Three SEPIC converters are designed and studied using different combinations of power devices: a combination based on all Si power devices using a Si–MOSFET and a Si–diode and termed as Si/Si, a combination based on a hybrid of Si and SiC power devices using the Si–MOSFET and a SiC–Schottky diode and termed as Si/SiC, and a combination based on all SiC power devices using a SiC–MOSFET and the SiC–Schottky diode and termed as SiC/SiC. The switching behavior of the Si–MOSFET and SiC–MOSFET is characterized and analyzed within the different combinations at the converter level. The effect of the diode type on the converter’s overall performance is also discussed. The switching energy losses, total power losses, and the overall performance efficiency of the converters are measured and reported under different switching frequencies. Furthermore, the potential of the designed converters to operate efficiently at a wide range of input voltages and output powers is studied. The analysis and results show an outstanding performance efficiency of the designed SiC/SiC based converter under a wide range of operating conditions.