hw1_solutions - Z . b) Calculate the real and reactive...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE 320: Energy Conversion and Power Electronics Name: Spring 2009 Homework #1 (Due: Monday, January 26, 2009) Circle or box your answer (don’t forget units). Staple any additional paper used to arrive at your answers to this sheet. 1. Fill in the blank spaces of the following table. Where the frequency is not included, assume 60(Hz). Phasor Sinusoidal Signal Polar Form Rectangular Form () ( ) º 10 1000 sin 7 + = t t i (A) 20 ˆ = V / -113º (V) = 6 377 cos π t A v (kV) 3 10 ˆ j I = (kA) 30 ˆ = I / -2 π /3 (A) 2. For the circuit shown in Figure 1: a) Find the current, power factor, real power, reactive power, and apparent power at the source and at the load, Z L . b) Calculate and sketch, the Thevenin and Norton Equivalent circuits at the terminals A - B and looking to the left. 208 / (V) j 2 ( Ω ) 5 ( Ω ) j 30 ( Ω ) - j 5 ( Ω ) 50 ( Ω ) Z = 10- j 3 ( Ω ) A B L Figure 1. Circuit for problem 2.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
3. For the three-phase (3 φ ) system shown in Figure 2, find: a) Line currents, and for the Δ connected load calculate the current through one leg of the delta,
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 12
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Z . b) Calculate the real and reactive power at each load and at the source. Do they balance? Why, or why not? n' + + 12 + j9 ( ) 10 - j15 ( ) j 2 ( ) n j 2 ( ) j 2 ( ) 120 / 0 (V) 1.5 ( ) 1.5 ( ) 1.5 ( ) Figure 2. Three-phase system with Y and connected loads. 4. Figure 3(a) shows a 3 source of 480 (V) line-to-line with Load 1 connected. Load 1 is a 3 load that absorbs 150 (kW) at a power factor of 0.7 lagging. Load 2 is then added as shown in Figure 3(b) and it absorbs an additional 50 (kW) and changes the power factor of the total load (Load 1 and Load 2 together to 0.9 lagging). a) What is the power factor of Load 2? b) What is the source current S I before and after the addition of Load 2? Power System Load 1 I S a) Power System Load 2 Load 1 I S b) Figure 3. Three phase power system with one load connected, then a second load is added....
View Full Document

This note was uploaded on 05/30/2009 for the course ECE ECE 320 taught by Professor Timhogan during the Spring '09 term at Michigan State University.

Page1 / 12

hw1_solutions - Z . b) Calculate the real and reactive...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online