Читать книгу Soft-Switching Technology for Three-phase Power Electronics Converters - Rui Li - Страница 27

With development of big data, cloud computing, etc., it is more stringent than ever to require the data centers to have higher computing speed and density with less energy consumption. Compared with super junction Metal‐oxide‐semiconductor field effect transistors (MOSFETS), Gallium nitride high Electron mobility Transistor (GaN HEMT) shows significant improvement on the switching performance, but its switching frequency is still limited when hard switching is used. A ZVS totem‐pole PFC circuit with fixed switching frequency is investigated for server power supply [34]. In Figure 1.28, the right leg with switch S_2H and S_2L operates at utility frequency and silicon MOSFET is used. The left leg with S_1H and S_1L operates at 500 kHz and GaN HEMT is chosen. With the auxiliary circuit, the GaN device can operate at ZVS condition. The turn‐on loss of the GaN is eliminated and its turn‐off loss is reduced.