Three-Phase Two-Third-PWM Buck-Boost Current Source Inverter System Employing Dual-Gate Monolithic Bidirectional GaN e-FETs

Abstract

Latest dual-gate (2G) monolithic bidirectional (MB) gallium nitride (GaN) enhancement-mode field effect transistors (e-FETs) enable a performance breakthrough of current DC-link inverters, e.g., in terms of power conversion efficiency, power density, cost and complexity. In fact, a single 2G MB GaN e-FET can replace the two anti-series connected conventional power semiconductors required in this inverter topology, realizing a four-quadrant (AC) switch with bidirectional voltage blocking capability and allowing controlled bidirectional current flow. Furthermore, as shown in this paper in case of three-phase (3-Φ) buck-boost (bB) current source inverter (CSI) systems comprising a DC-link current impressing buck-type DC/DC input stage and a subsequent boost-type 3-Φ current DC-link inverter output stage, a variable DC-link current control strategy, based on aSynergetic Control concept, can be applied to significantly reduce the switching losses occurring in the 3-Φ inverter. This strategy is denominated two-third pulse-width modulation (2/3-PWM), since by properly shaping the DC-link current with the input stage, the desired 3-Φ sinusoidal load phase currents can be generated by switching, in each switching period, only two out of the three phases of the output stage. Based on comprehensive circuit simulations and analytical calculations, a detailed explanation of the developed modulation and control schemes in different operating conditions is provided, and the reduction of losses enabled by 2/3-PWM is confirmed. Next, the seamless transition of the 3-Φ bB CSI system from 2/3-PWM to conventional 3/3-PWM is demonstrated. Finally, a 3.3 kW 3-Φ bB CSI system, applying 2/3-PWM and employing research samples of 2G MB GaN e-FETs in the 3-Φ inverter, is estimated to achieve an efficiency of 98.4% and a power density of 18 kW/dm 3 (295 W/in 3 ) at a switching frequency of 140 kHz. Index Terms-Dual-gate (2G) monolithic bidirectional (MB) gallium nitride enhancement-mode field-effect transistors (e-FETS), three-phase buck-boost current source inverter system, variable DC-link current control. in 2001, all inElectronic Engineering. In 1991, he joined Panasonic Corporation, Osaka, Japan, where he was engaged in the research and development of GaAs HFETs, HBTs, and GaAs MMICs. Since 2003, is involved in the research on GaN-based semiconductor devices. He authored or coauthored more than 60 technical papers in international journals and conference proceedings. He submitted more than 60 patents on semiconductor devices and on their process technologies. His current interest is on GaN-based bidirectional switches and on their applications.

Overview of Power Electronic Switches: A Summary of the Past, State-of-the-Art and Illumination of the Future

“…The use of reverse blocking switches have become a subject or research as they now bring a possibility of reducing the two diodes that would have been used in Figure 15 a,b [ 147 ]. The configuration in 15d uses a diode bridge and a switch, this might be functional in some matrix converters but increases losses and might not be applicable in multi-level inverters [ 148 ].…”

“…The use of reverse blocking switches have become a subject or research as they now bring a possibility of reducing the two diodes that would have been used in Figure 15a,b [147]. The configuration in 15d uses a diode bridge and a switch, this might be functional in some matrix converters but increases losses and might not be applicable in multi-level inverters [148]. Also, in Figure 16, a summary-comparison of the ideal V-I and other characteristics of some of the most prominent power electronic switches is presented, it is seen that the ideal switch has some of the most desirable characteristics when it comes to bidirectional current flow and voltage blocking characteristics among many others.…”

“…Properties and Electrical Characteristics of Semiconductor Materials[20,148,189,[203][204][205][206][207][208][209][210][211].…”

New FOM-Based Performance Evaluation of 600/650 V SiC and GaN Semiconductors for Next-Generation EV Drives

“…√ r ds,on q oss + k i f sw V sw τ rr (22) where k i is a coefficient taking into account the bridgeleg current waveform, namely k i = 1 /2 for DC (e.g., buck converter, boost converter, CSI) and k i = √ 2 /π for sinusoidal AC (e.g., VSI topologies). Therefore, a hard-switching figureof-merit (HSFOM) taking into account both semiconductor technology (i.e., r ds,on , q oss , τ rr ) and application (i.e., f sw , V sw ) can be defined as HSFOM = 1 √ r ds,on q oss + k i √ f sw V sw τ rr .…”

Three-phase boost-stage coupled current source inverter concept and its space vector modulation

“…To solve these problems, scholars tried to apply highperformance semiconductor switches, e.g. the reverse blocking IGBTs (RB-IGBTs), silicon-carbide (SiC), and gallium nitride (GaN) based MOSFETs (Su and Tang, 2011;Guacci et al, 2019;Narasimhan et al, 2021). However, these attempts strictly depend on the high investment, so there is still a big gap between hardware allupgrade solutions and the actual applications.…”