Development of a GaN HEMT Type in Cascode Structure and Its Application to the Power Module used in the EEAT

With the New-type Power System construction progress of China, stricter requirements for the functionality and performance of the electricity energy acquisition terminal (EEAT) were proposed by the power grid designers. At present, there are sorts of EEATs using in the power grid such as DTU, the intelligent terminal and the distribution concentrator. The traditional power supply module of the EEAT was based on Si MOSFET, which had low operation efficiency and caused high electricity energy consumption. The power supply module in the new generation EEAT was required to be based on GaN HEMT (High Electron Mobility Transistor) to improve power supply efficiency, reduce operation temperature, achieve better stability and extend lifespan of the module, and it also could save more power during the usage process. In this article, a type of GaN HEMT device, which had 1100V+ voltage resistance capability was developed. A Cascode structure was introduced to design the GaN HEMT. Moreover, a power module based on the newly developed GaN HEMT was applicated. The efficiency of the GaN HEMT-based module was compared in specifications with a Si MOSFET-based module. The test results showed that the efficiency of power modules based on GaN HEMT was generally higher than that of Si MOSFET-based module. At present, the power modules based on GaN HEMT have implemented for batch application in the EEATs.