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This paper proposes new modulated carrier control (MCC) method for power factor correction (PFC) rectifier which provides high power factor (PF) and low total harmonic distortion (THD) regardless of continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The proposed control method employs a modified MCC control circuit based on the conventional MCC using average current sensing...
Gallium Nitride (GaN) transistors are emerging as promising candidates for making high-frequency, low-loss and small-size power converters. To realize normally-off, p-GaN gate technique is widely adopted in commercially available GaN-based power devices. However, owing to the distinctions in device structure, the intrinsic capacitances with regard to gate region vary from those of Si MOSFET. Besides,...
GaN-FETs are attractive switching devices for their fast switching capability. However, they often suffer from the oscillatory false triggering, i.e. a series of self-sustaining repetitive false triggering induced after a fast switching. The purpose of this paper is to derive a design instruction to prevent this phenomenon. According to the previous study, the oscillatory false triggering was found...
Vertical GaN power semiconductors promise higher power with faster switching speeds but the development of this technology has been slowed. This is due to the expense and lack of familiarity with GaN substrates. This paper will detail the functionality of HRL's cutting-edge vertical GaN transistor which is mounted onto a specially made PCB and tested. The testing consists of a static characterization...
A capacitor voltage balancing method for a three phase modular multilevel DC-DC converter (MMDC) is proposed in the paper. The MMDC is derived from a three phase DAB and a modular multilevel converter (MMC) and inherits desirable features of both topologies. To guarantee stable operation of the MMDC, submodule (SM) capacitor voltages are required to be balanced. The proposed balancing method is to...
1700V SiC modules were built with next-generation SiC MOSFETs, with 25°C RDSON per MOSFET cut approximately 50% from existing commercial SiC MOSFETs. Additionally, the external SiC anti-parallel diode was eliminated in favor of using the SiC MOSFET body diode during the dead time. The resulting 1700V SiC module used only 32% of the SiC chip area, yet reduced the 25°C module RDSON from 8mΩ to 5mΩ,...
The reverse recovery characteristics of the body diodes of planar and double-trench SiC MOSFETs are experimentally analyzed in switching tests and compared. The body diode of the trench SiC MOSFET shows improved performance, so that using an anti-parallel SBD to suppress the reverse recovery behavior becomes unnecessary. Following the switching tests, the devices are operated in continuous mode in...
Silicon carbide (SiC) power semiconductor technology has successfully penetrated several silicon (Si) application markets and is gaining momentum due to higher voltage withstand capability, higher switching capabilities (i.e., 100s of kHz), and ability to withstand higher operating temperatures (i.e., more than 200°C). When properly applied, SiC MOSFETs can switch in nanoseconds making this a promising...
A general fault diagnosis method is proposed for modular dc-dc converter system. The magnetic component voltage in each module is chosen as diagnostic signal, which can be easily obtained by adding an auxiliary winding into each magnetic core. Based on the feature of these signals, two logical hardware circuits are designed to achieve fast fault detection for different demands. Fault can be detected...
A health monitoring method using the saturationregion resistance is proposed in this paper to identify the level of aging associated with power semiconductor switches inside a Boost converter. Power MOSFETs are one of the most age-affected components in power electronic converters, and the on-resistance has been proved to be the most significant aging factor in power MOSFETs. However, the small value...
In this paper, a comparative evaluation between a commercial 3.3 kV/400 A Si-IGBT and a 3.3 kV/400 A SiC MOSFET power module in half-bridge configuration is presented. With a constant current of 250 A, a lower forward voltage (VDS) drop of 1.6 V is obtained for SiC MOSFET at 300 K compared to Si IGBT. At 400 A, the difference is reduced to 1.3 V. SiC MOSFET offers an on-state resistance of 8.7 mΩ,...
With their intrinsic superiorities such as high breakdown electric field and high thermal conductivity, SiC MOSFETs are replacing Si IGBTs in power electronics applications. However, at higher voltages SiC MOSFETs are at early stage of development and are not commercialized yet. For the first time, this paper presents thorough static and dynamic performance characterization of 3.3 kV and 30 A discrete...
The advancements in wide-band-gap (WBG) devices are enabling applications of power electronics converters coupled directly to medium voltage and incorporating galvanic insulation within the converter using high-frequency solid-state transformers. This paper presents the design and the characterization results of a SiC H-bridge converter suitable for up to 100 kVA single-phase ac-dc modular solid-state...
This paper describes the effect of MOSFET internal capacitances on the channel current during the turn-on switching transition: an intrinsic theoretical switching speed limit is found and detailed mathematically. The set of analytical equations is solved and the effect of the displacement currents is highlighted with ideal simulated waveforms. A laboratory experiment is thus performed, in order to...
GaN HEMT is generally characterized as fast switching and expected to achieve a power converter with high efficiency and high power density as a next-generation power semiconductor. However, the fast switching generates large switching noise, causing gate voltage fluctuation. Therefore, GaN HEMT can suffer from false triggering such as a false turn-on phenomenon due to its own low threshold voltage...
In this study, design considerations of gate driver for silicon carbide (SiC) power devices is discussed. The work is focused in minimizing the common-mode current injection into the control circuit, thereby adapting the gate circuit to operate at higher dv/dt of fast switching transients. By reducing the common-mode interference with the control circuit, the signal integrity can be increased, spurious...
This paper proposes a Zero-Voltage Ride-Through (ZVRT) method and an LCL filter optimization design method to meet the Fault Ride Through (FRT) requirements for a singlephase grid-tied inverter with a minimized LCL filter. The inverter output current overshoots at a voltage sag when the small LCL filter is used. As a proposed method in this paper, the inverter output current overshoot is suppressed...
This paper proposes an Active Gate Current Control (AGCC) strategy for non-insulating gate WBG devices, for example, gallium nitride gate-injection-transistor (GaN-GIT) and silicon carbide super junction transistor (SiC-SJT). It provides a tool for power converter designers to further improve the converter efficiency and to extend the life time of those higher cost power transistors. By continuously...
With switching transients as fast as 100 V/ns and a low threshold voltage of 1–2 V, GaN FETs in bridge-leg topologies are potentially vulnerable to crosstalk and the resultant unwanted partial turn-on, noise interference, and increased losses. Constant-strength gate drivers for GaN FETs limit switching speed to suppress crosstalk. In this work, active gate driving is shown to permit faster switching,...
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