by Wibawa T. Chou, International Rectifier Corp., wtjokr01@irf.com, Electronic Design, Aug 13 2009
Focus:
A 500-W inverter design converts 200 V dc from a solar panel to 120-V, 60-Hz single-phase, sinewave output using high-voltage IGBTs in a full-bridge topology. To minimize the size of output inductors, the two high-side IGBTs are pulse-width modulated at 20 kHz or higher with 50/60 Hz modulation. The two low-side IGBTs switch at 60 Hz. Article explains 1) why IGBTs are the best option for the power switches in this application, 2) why ultrafast trench IGBTs are the best choice for the high-side IGBTs, and 3) why standard-speed planar IGBTs are the best choice for the low-side devices. Article presents inverter schematic, describes how the IGBTs are driven, and present measurements of the inverter's power loss and efficiency across the output power range. Efficiency is greater than 97% from 100 W to 500 W.
What you’ll learn:
Notes:
For guidance on how to select the power switches required in this 500-W inverter design, see Wibawa Chou's article, "Choose Your IGBTs Correctly for Solar Inverter Applications," Power Electronics Technology, August 2008, available online at http://powerelectronics.com/power_semiconductors/igbts/choose_igbts_solar_inverter_applications/.
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