Lecture Notes14_AcPower

I used for machine ratings average power p s v i

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Unformatted text preview: = 100 A ⇒ I 2 R = 10 kW losses. 100 kVA@ 100 kV = 1 A ⇒ I 2 R = 1 W losses. Voltage Conversion Electronic equipment requires ≤ 20 V but mains voltage is 240 V ∼. Interference protection Microphone on long cable is susceptible to interference from nearby mains cables. An N : 1 transformer reduces the microphone voltage by N but reduces interference by N 2 . E1.1 Analysis of Circuits (2013-3867) AC Power: 14 – 10 / 11 Transformer Applications 14: Power in AC Circuits • Average Power • Cosine Wave RMS • Power Factor • Complex Power • Power in R, L, C • Tellegen’s Theorem • Power Factor Correction • Ideal Transformer • Transformer Applications • Summary Power Transmission Suppose a power transmission cable has 1 Ω resistance. 100 kVA@ 1 kV = 100 A ⇒ I 2 R = 10 kW losses. 100 kVA@ 100 kV = 1 A ⇒ I 2 R = 1 W losses. Voltage Conversion Electronic equipment requires ≤ 20 V but mains voltage is 240 V ∼. Interference protection Microphone on long cable is susceptible to interference from nearby mains cables. An N : 1 transformer reduces the microphone voltage by N but reduces interference by N 2 . Isolation There is no electrical connection between the windings of a transformer so circuitry (or people) on one side will not be endangered by a failure that results in high voltages on the other side. E1.1 Analysis of Circuits (2013-3867) AC Power: 14 – 10 / 11 Summary 14: Power in AC Circuits • Average Power • Cosine Wave RMS • Power Factor • Complex Power • Power in R, L, C • Tellegen’s Theorem • Power Factor Correction • Ideal Transformer • Transformer Applications • Summary • Complex Power: S = V I ∗ = P + jQ where V = Vrms = E1.1 Analysis of Circuits (2013-3867) 1 √V 2 . AC Power: 14 – 11 / 11 Summary 14: Power in AC Circuits • Average Power • Cosine Wave RMS • Power Factor • Complex Power • Power in R, L, C • Tellegen’s Theorem ...
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This document was uploaded on 02/20/2014 for the course EE 101 at WVU.

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