Voltage Power Electronics Applications Research Articles

Additive Manufacturing as an Insulator for Medium Voltage Power Electronics Applications

Additive Manufacturing as an Insulator for Medium Voltage Power Electronics Applications

Medium Voltage Power Switch in Silicon Carbide—A Comparative Study

This paper discusses various solutions of energy conversion in medium voltage using power switches in Silicon Carbide (SiC) technology. In particular, a comparative study is focused on four different variants of an inverter phase leg operating at 1.5 kV DC, which has not been presented in the literature yet. The first one is based on a standard two-level half-bridge built from a 3.3 kV SiC MOSFET power module rated at 450 A. Then, the two-level solution with series-connected devices inside 1.2 kV/450 A power modules is taken into account. Finally, a flying-capacitor phase leg also based on the same 1.2 kV devices is investigated in two different modes: a standard three-level operation and quasi-two-level mode with a significantly reduced capacitor. The presented study is founded on in-depth experiments: all four phase legs were designed, built, and tested in the laboratory. All versions were connected in a half-bridge configuration with an inductive load. Tests were conducted under identical conditions to test the overall performance and switching behavior for various gate resistances. In addition, different aspects are analyzed and compared in this paper, including parasitics, cooling performance, gate drivers and layout considerations, providing selection guidelines for power switches with SiC power devices in medium voltage power electronics applications.

Simulation and Implementation PID Controlling Buck Converter DC

Regulating the output voltage based on the desired set point is useful for many applications. However, getting the optimal value using fast computation with minimal error is still challenging. This paper aims to design, simulate, and implement a second-order Buck-Boost DC-DC converter circuit so that the voltage result according to the desired set point can be achieved. Initially, testing is conducted using Matlab Simulink. Then, Proteus is used to test the computation of the program on embedded systems in which the result is implemented in C. In low voltage power electronics applications, this approach has never been used to determine the output form. To determine the value of Kp, Ki, dan Kd, PID, Ziger Nichos (Guo, 2002). method is used. Meanwhile, tuning is done through Matlab. For simulation on Proteus, the output is tested by setting the setpoint values of 3.0, 2.5, and 1.7 volts. This aims to see the pattern of changes in the simulation. The simulation results with Proteus show that they have similar peak values but with different overshoot values. This is because the simulation must pass the reference voltage before it drops to the desired setpoint value. Proteus simulation can also help to prove embedded system programs are running correctly. On the other hand, the value of 1.7 volts is used as a setpoint in device implementation. This is due to the determination that the setpoint voltage in the implementation does not exceed the value of the source/power supply. The results show that for the rise time value of 378,770 ms, Overshoot and settling time are 11.798% and 0, respectively. This means the result produces an optimal value which is a return to the initial target. The optimal factor is assessed from the ability to minimize existing errors as well as having the shortest possible computational process.

(Invited) Simulation Study of High Voltage Vertical GaN Nanowire Field Effect Transistors

Concept of vertical Gallium Nitride (GaN) nanowire field effect transistors (NWFETs) for high voltage power electronic applications is investigated through three dimensional (3D) TCAD simulations in this paper. The proposed GaN NWFET can operate either in a normally-off or a normally-on mode depending on the specific device design. A gate-all-around (GAA) structure coupled with a strong dielectric REduced SURface Field (RESURF) effect has the potential to offer blocking voltages over 900 V with very low specific on-resistance for the NWFETs. VRB 2/RON and QGD x RDS(ON) Figures of Merits (FoMs) of the NWFET are extracted and compared with other state of the art GaN, SiC and Si field effect transistors to get a comparative understanding of the potential of the NW architecture for high voltage applications.

Thermal performance of a PCB embedded pulsating heat pipe for power electronics applications

Low voltage power electronics applications (<1.2 kV) are pushing the design envelope towards increased functionality, better reliability, low profile and reduced cost. One packaging method to enable these constraints is the integration of active power electronic devices into the printed circuit board improving electrical and thermal performance. This development requires a reliable passive thermal management solution to mitigate hot spots due to the increased heat flux density. To this end, a 44 channel open looped pulsating heat pipe (OL-PHP) is experimentally investigated for two independent dielectric working fluids – NovecTM 649 and NovecTM 774 – due to their lower pressure operation and low global warming potential compared to traditional two-phase coolants. The OL-PHP is investigated in vertical (90°) orientation with fill ratios ranging from 0.30 to 0.70. The results highlight the steady state operating conditions for each working fluid with instantaneous plots of pressure, temperature, and thermal resistance; the minimum potential bulk thermal resistance for each fill ratio and the effective thermal conductivity achievable for the OL-PHP.

SYSTEM IMPACT OF SILICON CARBIDE POWER DEVICES

The emergence of silicon carbide- (SiC-) based power semiconductor switches, with their superior features compared with silicon- (Si-) based switches, has resulted in substantial improvements in the performance of power electronics converter systems. These systems with SiC power devices have the qualities of being more compact, lighter, and more efficient; thus, they are ideal for high voltage power electronics applications such as a hybrid electric vehicle (HEV) traction drive. More research is required to show the impact of SiC devices in power conversion systems. In this study, findings of SiC research at Oak Ridge National Laboratory (ORNL) including SiC device design and system modeling studies, will be given.

Evaluation of high temperature dielectric films for high voltage power electronic applications

Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200°C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250°C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200°C. However, above 200°C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.