A Comparative Study on the Switching Performance of GaN and Si Power Devices for Bipolar Complementary Modulated Converter Legs

Abstract

The commercial mature gallium nitride high electron mobility transistors (GaN HEMT) technology has drawn much attention for its great potential in industrial power electronic applications. GaN HEMT is known for low on-state resistance, high withstand voltage, and high switching frequency. This paper presents comparative experimental evaluations of GaN HEMT and conventional Si insulated gate bipolar transistors (Si IGBTs) of similar power rating. The comparative study is carried out on both the element and converter level. Firstly, on the discrete element level, the steady and dynamic characteristics of GaN HEMT are compared with Si-IGBT, including forward and reverse conducting character, and switching time. Then, the elemental switching losses are analyzed based on measured data. Finally, on a complementary buck converter level, the overall efficiency and EMI-related common-mode currents are compared. For the tested conditions, it is found that the GaN HEMT switching loss is much less than for the same power class IGBT. However, it is worth noting that special attention should be paid to reverse conduction losses in the PWM dead time (or dead band) of complementary-modulated converter legs. When migrating from IGBT to GaN, choosing a dead-time and negative gate drive voltage in conventional IGBT manner can make GaN reverse conducting losses high. It is suggested to use 0 V turn-off gate voltage and minimize the GaN dead time in order to make full use of the GaN advantages.

Effect of the Heat Dissipation System on Hard-Switching GaN-Based Power Converters for Energy Conversion

“…Additionally, graphite is affordable, abundant, and allows for the production of TIMs with improved physical properties. For example, graphite-enhanced TIMs are flexible and require low assembly pressures [61,62]. However, graphite has low electrical resistance, so these TIMs may include an isolation layer on the surface to ensure electrical isolation [58,59].…”

Feasibility Study GaN Transistors Application in the Novel Split-Coils Inductive Power Transfer System with T-Type Inverter

“…Therefore, a simplified equation is used to estimate the magnitude of switching losses quantitatively [18]:…”

“…It is advisable to use GaN transistors for T-type topologies [5][6][7][8]14]. The GaN features fast switching, low parasitic charges, reverse conductivity with zero recovery charge and low driving power losses and dynamic losses; compared to Si-IGBTs and SiC-MOSFETs [5,6,[15][16][17][18], higher efficiency, low parasitic output capacitance [16][17][18] can be achieved. The advantage of GaN over Si is mostly visible at higher frequencies in dynamic losses [15,19].…”

“…The advantage of GaN over Si is mostly visible at higher frequencies in dynamic losses [15,19]. However, the conduction losses are comparable with the SIC semiconductors [18,19].…”

Low-Voltage GaN FETs in Motor Control Application; Issues and Advantages: A Review

“…In the field of low voltage switching devices (with breakdown voltage up to 100 V), silicon (Si) MOSFETs with in trench-gate technology are low-cost standard switches available in a wide range of current rating and can reach quite satisfactory high switching frequencies [4,5]. Nowadays, high electron mobility transistors (HEMT) Gallium Nitride (GaN) devices are becoming increasingly used, especially in low voltage applications, due to their superior features, such as high dynamic characteristics, high power density and very high-temperature ratings, compared to pure silicon MOSFET devices with similar current rating [6]. In high voltage applications, GaN devices are in continuous development and compete with silicon carbide (SiC) MOSFETs, silicon (Si) super junction MOSFETs and IGBTs, which have higher technological maturity [7].…”