Experiment 6 Three-Phase Power Measurement
OBJECTIVE
0 To measure power in a three-phase circuit using the two wattmeter method.
0 To determine the active, reactive power, and the power factor of a three-phase system.
DISCUSSION
An analog wattmeter, used

EEE 360
Chapter 7:
Transformers
Transformers
Invention of transformers revolutionized
electrical energy transmission
A transformer can increase or decrease the
voltage, which correspondingly results in the
decrease or increase of the current
The develo

EEE 360
Review Midterm Test 2
Synchronous Generator
Synchronous Generator
1. Draw the equivalent circuit of the network and calculate impedances
and voltages
2. Simplify the network by transferring the impedances and voltages to
common base
3. Calculate t

EEE 360
Review Midterm Test 3
Final Exam
Transformer
Single phase 150kVA transformer with primary voltage of 2.5kV, secondary voltage is 240V
supplies a 75 kW,pf= 0.8 inductive load. The load voltage is equal with the secondary voltage of
240V
Calculate:

EEE 360 Laboratory
Fall 2014
INTRODUCTION
Safety:
Dont hurt yourself or others
Turn OFF power supply before changing the circuit in any way.
TAs:
Office location
Office hour
Mengjia Xiao
ERC 510
N/A
mxiao7@asu.edu
Meenakshi
Saravanan
ERC522
N/A
msaravan

EEE 360 Laboratory
Power Calculations
Ohms Law
V I Z
V V
I I
Z Z R jX
Inductive:
X L L
Capacitive:
XC
1
C
Power Factor
Pure Resistive = Unity
pf cos( ) cos( )
Inductive: Lagging
Capacitive: Leading
Power Calculations
Complex Power
Complex power:
S P

EEE 360
Review Midterm Test 1
Single phase circuits
Single phase circuits
Example 1
Calculate the impedance of the network (Zeq) given in
Figure 3.42 at (a) 50 Hz and (b) 60 Hz, using the
network circuit element values below.
Branch 1: R1 = 25
L1 = 0.1

5 Three-phase unbalanced load and unit system
Thee-phase wye connected generator supplies a delta conected unbalanced loads through a short
distribution line.
a) Draw the oneline diagram and equivalent circuit
b) Calculate the generator and transmission l

5 Three-phase unbalanced load and unit system
Thee-phase wye connected generator supplies a delta conected unbalanced loads through a short
distribution line.
a) Draw the oneline diagram and equivalent circuit
b) Calculate the generator and transmission l

Three phase Circuit with wye and delta concted loads.
Example 4
A three phase generator supplies two parallel connected loads. Load1
is connected in delta , Load 2 is connected in wye
Supply voltage is:
Vs_ll 208V
Load 1 Delta connected:
PD 322W
pfD 0.7
L

Three phase Circuit with wye and delta concted loads.
Example 4
A three phase generator supplies two parallel connected loads. Load1
is connected in delta , Load 2 is connected in wye
Supply voltage is:
Vs_ll 208V
Load 1 Delta connected:
PD 322W
pfD 0.7
L

Example 3 Matlab plotting the load reactive
power vs power factor
%System data
P_L=200*10^3;
pf_L=0.1:0.01:0.99;
% load in watt;
% variable start 0.1, step 0.1 end 1
%Calculation of reactive power
%Note that vector calculation (. / or.*,.+) needed for plo

Example 2 Load current calculation
%METLAB current calculation
%System data
P_wye=200*10^3;
pf_wye=0.7;
V_ll=440;
% load in wat
% power factor
% supply voltage in volt
%Calculations
S_wye_v=(P_wye/(pf_wye)*exp(j*acos(pf_wye)
I_wye_v=conj(S_wye_v/V_ll)
Iab

EEE 360
Chapter 4:
Three-Phase Circuits
Three-Phase Circuits
Practically all electrical energy generation and
transmission systems use a three-phase circuit.
The three-phase energy is transported through
three or four conductors to large customers.
Onl

EEE 360
Chapter 3:
Single-Phase Circuits
Single-Phase Circuits
An electric power system is usually a three-phase
system that contains generators, transformers,
transmission and distribution lines, and loads.
All of these components except loads are line

EEE 360
Chapter 2:
Electric Generating Stations
Electric Generating
Stations
Major Components
Electric Generating Stations
This chapter describes the various types of electric
power stations including fossil, nuclear, hydropower
and renewable generation.