Question

A three-phase bridge rectifier is used to provide DC power. The input voltage is 277/480V three phase. Determine the DC voltage output and harmonic content.

Answer 1

• Dc voltage output : 648.23 v
• Harmonic content : 27.19 v

Step-by-step explanation:

The DC voltage output can be calculated using this formula

Vo = 3Vp / π

Vp =
`√(2Vrms)`

Vrms = 480 v

therefore Vp =
`√(2 * 480)` = 678.82 v

Vodc = (3*678.82) / (22/7) = 648.23 V ( dc voltage output )

The harmonic content is calculated as

H =
`\sqrt{Vorms^(2) - Vodc^(2) }`

Vorms =
`(√(2Vrms*1.383) )/((2*3.14)/(3) )` = 648.797

back to initial equation

H =
`\sqrt{648.797^(2) - 648.23^(2) }`

H = 27.19 v

Answer 2

Step-by-step explanation:

DC output voltage, V₀

`V_(o) = 3V_(p) /\pi \\V_(p) = √(2)V_(rms) \\V_(rms) = 480\\V_(p) = √(2) * 480\\V_(p) = 678.82 V\\V_(o) = 3*678.82 /\pi\\V_(o) = 648.23 V`

To get the output rms voltage