A plastics extrusion plant in Ohio replaced motor starters with VFDs and cut drive energy use by 4%. Three months later, its 1000 kVA transformer ran 18 K above nameplate temperature, two capacitor banks tripped on overcurrent, and the utility applied a power-factor penalty. THDi on the 480 V bus measured 32% at full production. Adding capacitors would make that worse, not better. The fix i...
High-density data centers, semiconductor fabs, and offshore platforms expose a weakness in many silicon-based active harmonic filters (AHF) and static var generators (SVG): the correction target moves faster than the thermal design. At 20–25.6 kHz, a conventional silicon IGBT converter can correct current distortion, but switching loss, 45°C full-load temperature rise, heatsink volume, a...