Question

A single-phase inverter has square wave output voltage with input voltage of 80 V. The percentage of fifth harmonic component compared to the fundamental component will be _________ .

Answer 1

Output voltage of single-phase full bridge inverter,

$V_0=\sum _{n=1,3,\mathrm{5...}}^{\infty }\frac{4V_s}{n\pi }sinn\omega t$

Rms value of fundamental component,

$V_{01}=\frac{4V_s}{\pi \sqrt{2}}$

Rms value of fifth harmonic component,

$V_{05}=\frac{4V_s}{5\pi \sqrt{2}}=\frac{V_{01}}{5}$

Percentage of fifth harmonic component over first,

$\frac{V_{05}}{V_{01}}\times 100=\frac{1}{5}\times 100=20$