World’s first megawatt power module uses gallium oxide to handle huge currents

A research team from the University of Hong Kong and the Center for Advanced Semiconductors and Integrated Circuits has built the world’s first ultrawide-bandgap semiconductor module to reach 1 megawatt of peak power. In lab tests, the six-chip gallium oxide module switched 1,000 volts and 1,000 amperes at a rate of 1,000 times per second. Working with researchers at Virginia Tech and Nanjing University, the team moved the cooling path closer to the part of each chip where heat builds up and redesigned the insulation to handle high voltages. The findings could help engineers build smaller power systems that deliver short, intense bursts of electricity for fusion experiments, particle accelerators, and advanced medical equipment. Moving cooling closer to the chip Power semiconductors act as switches that control the flow of electricity in everything from electric vehicles to power grids. Gallium oxide can withstand strong electric fields, making it a candidate for high-voltage switches. But the material conducts heat poorly, and combining several chips in one package makes it harder to manage both heat and electrical stress. The researchers moved the heat-generating junction closer to the cooling path so heat could escape more readily. They also added an insulating layer with high permittivity to redistribute the electric field around the device and improve its ability to handle high voltage. “Our work shows that the thermal limitations of gallium oxide do not necessarily prevent it from reaching very high-power levels,” said Professor Zhang. “Instead of treating the semiconductor device and its package separately, we designed them together as a single system. This device-package co-design allowed us to simultaneously manage the electrical field, heat flow and mechanical stress,” he added. Six chips reach megawatt peak power In a pulsed test, a single packaged device conducted 234 amperes at 1,000 volts and remained functional at junction temperatures above 250°C. The team then combined six devices in one module and demonstrated repetitive switching at 1 kilohertz. The module reached 1 megawatt of peak power by switching 1,000 volts and 1,000 amperes. That was more than 100 times the power capability previously demonstrated with ultrawide-bandgap semiconductor technologies, according to the researchers. “This is the first time that an UWBG multi-chip module has reached the megawatt power level,” said Dr Gong. “More importantly, the result provides a scalable approach for translating the exceptional material properties of UWBG semiconductors into practical high-power systems,” he added. Where megawatt pulses could be useful Pulsed-power systems deliver energy in bursts that can last just microseconds. Gallium oxide’s high heat capacity per unit volume makes it attractive for these applications, where a switch must withstand both strong electric fields and brief temperature spikes. Potential uses include particle accelerators and fusion experiments, as well as advanced medical equipment and high-voltage grid protection. The module’s fast switching could also enable smaller and more efficient power-conversion systems. The findings were published in the journal Nature Communications. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Atharva is a full-time content writer with a post-graduate degree in media & amp; entertainment and a graduate degree in electronics & telecommunications. He has written in the sports and technology domains respectively. In his leisure time, Atharva loves learning about digital marketing and watching soccer matches. His main goal behind joining Interesting Engineering is to learn more about how the recent technological advancements are helping human beings on both societal and individual levels in their daily lives.