A 380 V/50 kVar SiC-SVG Achieving a Power Density of 1.652 kVar/L With the Optimization of Heatsink and Output Filter Volume

With the rapid development of new energy vehicles, 5G facilities, electric aircraft, and new energy power generation, the high-power-density inverters are developed rapidly. A comprehensive optimization method combining heatsink and inductance filter was proposed in this article. Based on accurate thermal modeling and magnetic modeling, the method proposed chose an optimized switching frequency to minimize the volume of the inverters by compromising the design of the heatsink and inductor volume. Among them, a model of multichip forced air-cooling heatsink was proposed to reduce the size of the heatsink, and the comprehensive thermal resistance error of the proposed model is within 2%. The structure of the grid-connected filter and the inductor model is analyzed showing that the single inductor L-filter has a smaller size and more stability than the LCL-filter at a high switching frequency. The comprehensive optimization method proposed was implemented by 380-V/50-kVar SiC-static var generator (SVG) with the 50-kHz switching frequency, and its topology is a two-level inverter with a single inductor filter. This SiC-SVG reached a volume of 30.2 L (including all components required for mainstream products), which is 50% lower than insulated gate bipolar translator (IGBT)-SVGs. Its efficiency is 98.5% at full load, which is 1.5% higher than IGBT-SVGs. The experiments and temperature rising tests at full load proved the feasibility of the comprehensive optimization method.