Week 11
Filters and Harmonics
I organize a study path from switching devices to converters and inverters while tracking power flow and device stress together.
What I connect in this unit
An LC filter attenuates switching ripple but creates a natural resonance; an LCL filter provides steeper high-frequency attenuation at the cost of another resonant mode. Total harmonic distortion compares harmonic RMS content with the fundamental, and resonance damping reduces the peak through resistance or control.
Concept map
- LC filters
- LCL filters
- Total harmonic distortion
- Resonance damping
Technical anchor
A simple LC filter has f_0 = 1/(2 pi sqrt(LC)), and THD = sqrt(sum from n=2 of V_n^2)/V_1.
How I review it
Verify resonance separation from both fundamental and switching bands, then check capacitor ripple current, inductor saturation, and the loss-stability trade-off of passive or active damping.
Connection to the full course
Unit 11 of 12. Unit numbers follow circuit dependencies and do not claim the original lecture schedule.