Calculating the efficiency and regulation of transformer using Matlab project. This project uses two approaches first in GUI and other is

1. Name : Mafaz Ahmed
CALCULATING THE EFFICIENCY AND
REGULATION OF TRANSFORMER

2. Abstract:
In this project the ideal have been
develop to find the Efficiency and Regulation of a
transformer using Matlab and GUI. We will be using
the values from the OPEN circuit test and short
CIRCUIT test. In this project I have use approaches
to find the efficiency and regulation, first by using
simple code and second by using GUI.
Machine:
A machine is a tool containing one or
more parts that uses energy to perform an intended
action. Machines are usually powered by mechanical,
chemical, thermal, or electrical means, and are often
motorized.
Types of Machines:
 Transformer
 Generator
 Motor
Transformer:
A transformer is an electrical
device that transfers energy between two or more
circuits through electromagnetic induction.
Working and Construction:
A varying current in the transformer's
primary winding creates a varying magnetic flux in
the core and a varying magnetic field impinging on
the secondary winding. This varying magnetic field at
the secondary induces a varying electromotive
force (emf) or voltage in the secondary winding.
Making use of Faraday's Law in conjunction with high
magnetic permeability core properties, transformers
can thus be designed to efficiently
change AC voltages from one voltage level to another
within power networks.
According to faraday’s law of induction, we have
And

3. Step-Up Transformer:
On a step-up transformer there
are more turns on the secondary coil than the
primary coil. The induced voltage across the
secondary coil is greater than the applied voltage
across the primary coil or in other words the voltage
has been “stepped-up”.
Step-Down Transformer:
A step down
transformer has less turns on the secondary coil that
the primary coil. The induced voltage across the
secondary coil is less the applied voltage across the
primary coil or in other words the voltage is “stepped-
down”.
Efficiency of a Transformer:
Efficiency of a
transformer can be defined as the output power
divided by the input power. As follows
The graph of efficiency vs output power is given
below

4. Transformer Voltage Regulation:
Voltage
Regulation is a measure of change in the voltage
magnitude between the sending and receiving end of
a component, such as a transmission or distribution
line. Voltage regulation describes the ability of a
system to provide near constant voltage over a wide
range of load conditions.
Voltage regulation of transformer at lagging power
factor,
Voltage regulation of transformer at leading power
factor,
IMPLEMENTING Efficiency and
Regulation IN MATLAB:
1st
Approach Using just M-File:
Code:
close all
clear all
clc
disp('CALCULATING THE TRANSFORMER
EFFICIENCY AND REGULATION')
kva=input('KVA RATING = ');
v1=input('V1 = ');
v2=input('V2 = ');
disp('Enter the vales of OPEN
CIRCUIT')
vo=input('Enter the open cicuit
voltage Vo in volts = ');
io=input('Enter the open cicuit
current Io Ampare = ');
wo=input('Enter the open cicuit
power Wo in Watts = ');
disp('Enter the vales of SHORT
CIRCUIT')
vsc=input('Enter the short cicuit
voltage VSC in Volts= ');
isc=input('Enter the short cicuit
current ISC in Ampare= ');
wsc=input('Enter the short cicuit
power Wsc in Watts = ');
disp('POWER FACTOR')
cosqo=wo/(io*vo)
disp('Component Current')
ic=io*cosqo
disp('Magnetizing Current ')
s=acosd(0.1);
sinqo=sind(s);
im=io*sinqo
disp('Value of Ro')
ro=vo/ic
disp('Reactance Xo')
xo=vo/im
disp('Now For SHORT circuit')
disp('Resistance')

5. r1e=wsc/(isc*isc)
disp('Impedance')
z1e=vsc/isc
disp('Reactance')
x=r1e*r1e;
y=z1e*z1e;
c=y-x;
x1e=sqrt(c)
z=input('"0" for lagging power
factor and "1" for leading power
factor ');
switch(z)
case 0
cosq2=input('Power Factor on
lagging for efficiency = ');
cosq=input('Power Factor on
lagging for Regulation = ');
disp('VOLTAGE REGULATION OF
A TRANSFORMER')
d=acosd(cosq);
sinq=sind(d);
R=((isc*r1e*cosq+isc*x1e*sinq)/v1)*1
00
case 1
cosq2=input('Power Factor on
leading for efficiency = ');
cosq=input('Power Factor on
leading for Regulation = ');
disp('VOLTAGE REGULATION OF
A TRANSFORMER')
d=acosd(cosq);
sinq=sind(d);
R=((isc*r1e*cosq-
isc*x1e*sinq)/v1)*100
end
disp('EFFICIENCY OF A TRANSFORMER')
n=((kva*cosq2)/(kva*cosq2+wo+wsc))*1
00
for i=1:100
m(i)=(i/100)*((kva*cosq2)/((i/100)*(
kva*cosq2)+wo+wsc*(i/100)^2))*100;
Rg(i)=(((i/100)*isc*r1e*cosq-
(i/100)*isc*x1e*sinq)/v1)*100;
end
subplot(2,1,1)
plot(m);title('Efficiency');
subplot(2,1,2)
plot(Rg);title('Regulation');
After Executing the code and what
parameters are define:
CALCULATING THE TRANSFORMER EFFICIENCY AND
REGULATION
KVA RATING = 5000
V1 = 500
V2 = 250
Enter the vales of OPEN CIRCUIT
Enter the open cicuit voltage Vo in volts = 500
Enter the open cicuit current Io Ampare = 1
Enter the open cicuit power Wo in Watts = 50
Enter the vales of SHORT CIRCUIT
Enter the short cicuit voltage VSC in Volts= 25
Enter the short cicuit current ISC in Ampare= 10
Enter the short cicuit power Wsc in Watts = 60
POWER FACTOR
cosqo =
0.1000
Component Current
ic =
0.1000
Magnetizing Current
im =

6. 0.9950
Value of Ro
ro =
5000
Reactance Xo
xo =
502.5189
Now For SHORT circuit
Resistance
r1e =
0.6000
Impedance
z1e =
2.5000
Reactance
x1e =
2.4269
"0" for lagging power factor and "1" for leading
power factor 0
Power Factor on lagging for efficiency = 0.8
Power Factor on lagging for Regulation = 0.8
VOLTAGE REGULATION OF A TRANSFORMER
R =
3.8723
EFFICIENCY OF A TRANSFORMER
n =
97.3236
Graph:
2nd
Approach using GUI:
Code:
% --- Executes on button press in
pushbutton1.
function
pushbutton1_Callback(hObject,
eventdata, handles)
% hObject handle to pushbutton1
(see GCBO)
0 10 20 30 40 50 60 70 80 90 100
40
60
80
100
Efficiency
0 10 20 30 40 50 60 70 80 90 100
-2
-1.5
-1
-0.5
0
Regulation

7. % eventdata reserved - to be
defined in a future version of
MATLAB
% handles structure with handles
and user data (see GUIDATA)
kv=str2num(get(handles.kva,'string')
);
pv=str2num(get(handles.v1,'string'))
;
sv=str2num(get(handles.v2,'string'))
;
V_o=str2num(get(handles.vo,'string')
);
P_o=str2num(get(handles.wo,'string')
);
I_o=str2num(get(handles.io,'string')
);
V_s=str2num(get(handles.vse,'string'
));
P_s=str2num(get(handles.wse,'string'
));
I_s=str2num(get(handles.ise,'string'
));
Pf=str2num(get(handles.pf,'string'))
;
%Pf=P_o/(I_o*V_o)
ic=I_o*Pf
s=acosd(0.1);
sinqo=sind(s);
im=I_o*sinqo;
ro=V_o/ic;
xo=V_o/im
r1e=P_s/(I_s*I_s)
z1e=V_s/I_s
x=r1e*r1e;
y=z1e*z1e;
c=y-x;
x1e=sqrt(c);
disp('EFFICIENCY OF A TRANSFORMER')
n=((kv*1000*Pf)/(kv*1000*Pf+P_o+P_s)
)*100
d=acosd(Pf);
sinq=sind(d);
R=((I_s*r1e*Pf-I_s*x1e*sinq)/pv)*100
for i=1:100
m(i)=(i/100)*((kv*1000*Pf)/((i/100)*
(kv*1000*Pf)+P_o+P_s*(i/100)^2))*100
;
Rg(i)=(((i/100)*I_s*r1e*Pf-
(i/100)*I_s*x1e*sinq)/pv)*100;
end
axes(handles.eff)
plot(m);
%title('Efficiency vs %load
current');
xlabel('Percentage Load Current',
'color', [0 0 0.5],'erasemode',
'xor')
ylabel('eta %', 'color', [0 0
0.5], 'erasemode', 'xor')
axes(handles.reg)
plot(Rg);
%title('Regulation vs %load
current');
xlabel('Percentage Load Current',
'color', [0 0 0.5],'erasemode',
'xor')
ylabel('Voltage Regulation',
'color', [0 0 0.5], 'erasemode',
'xor')
PLOT:
The graph show the efficiency and
regulation of a transformer and we can analyze the
efficiency and regulation using graph.

8. WHAT I LEARN:
 How to implement a transformers equations
in matlab.
 How to find the cosine and sin of radian and
degree. Both have different syntax in matlab.
 How to find the inverse of cosine and sin.
 How efficiency and voltage regulation
behaves in transformers.
 How efficiency is different from voltage
regulation.
 How to find efficiency of a transformer.
 How to find the voltage regulation of a
transformer.
 How to use GUI.
Conclusion:
In the initial state, the efficiency
of a transformer is low as shown in the figure, but it
increase to a stable value as it gets stable. On the
other hand the graph of the regulation is decreasing,
and it gets to the minimum value after short little
time. So we can conclude that for a good transformer
efficiency should be high and on the other hand
regulation should be small.
Using this method we can find any
transformer efficiency and regulation by just entering
the values(parameters) and we will get the efficiency
and regulation, and their graphs. With which we can
analyze that transformer.
References:
 http://driverlayer.com/img/efficiency%20of%
20transformer/20/any
 Signal and system labs Handouts.
 http://www.mathworks.com/help/matlab/ref
/asin.html
 http://www.electricaleasy.com/2014/04/tran
sformer-losses-and-efficiency.html