it is very useful for 2 d year electrical students,this ppt will explain in depth of experiment about dc compound generator.

1. WELCOME
THIAGARAJAR COLLEGE OF ENGINEERING
(A Govt. Aided, ISO 9001:2008 Certified, Autonomous Institution Affiliated to Anna University)
MADURAI – 625 015
Department of Electrical and Electronics Engineering

2. LOAD TEST ON DC
COMPOUND GENERATOR
(LONG SHUNT)
PRESENTED BY,
V.Rajalakshmi -14E87 T.Naveena -14E80
R.Priyadharshini -14E85 T.Palani Kumar -14E83
S.P.Nandhini -14E79 P.Prakash -14E84
S.Priyanka -14E86 S.Padmanathan -14E82

3. Dc compound
generator
Cumulatively Differential
Long Shunt
Short
Shunt

4. CHARACTERISTICS

5. Aim:
To conduct load test on DC compound generator (long shunt)and to determine its
characteristics.
Internal characteristics – generated emf Vs armature current
External characteristics - terminal voltage Vs load current
S NO APPARATUS SPECIFICATION QUANTITY
1 MC VOLTMETER (0-300V) 1
(0-10V) 2
2 MC AMMETER (0-50A) 1
(0-1A) 1
3 RHEOSTAT 910Ω,0.7 A 2
4 CARBON RHEOSTAT 50Ω,4.1A 1
5 LOAD (40A,160V) 1
APPARATUS REQUIRED:

6. NAME PLATE DETAILS:
S NO PARAMETERS MOTOR GENERATOR
1 RATED VOLTAGE 230V 160V
2 RATED CURRENT 35.7A 38A
3 RATED SPEED 1450rpm 1450rpm
4 RATED POWER 7KW 6.1KW
5 RATED FIELD
CURRENT
0.58A 0.58A
FORMULAE USED:
Eg = V + Ia (Ra+Rf), Ia =load current+ filed current
Eg = generated emf
Ia = armature current
Ra = armature resistance
Rf = series filed resistance

8. PROCEDURE:
1. Make the connections as shown in the figure
2. Keep the D.C motor field in minimum position and generator rheostat in
maximum position initially load should not be connected to generator out put
terminals and are open circuited.
3. Motor started with the help of a 3-point starter and its field regulator is adjusted
so that rated speed of motor obtained
4. The gen field rheostat is also adjust such that the rated voltage is obtained at
the gen terminals.
5. By keeping the gen field excitation constant load is switched on varied in steps
and meters readings are tabulated.
6. In each step of load variation readings are taken the motor is running at rated
speed is achieved by adjusting motor field rheostat variation of load in speed is
continued till the generator supplies rated current.
7. When the current exceeds gen rated current decrease the load to zero and open
the DPST

9. S NO FIELD
CURREN
T
If(A)
LOAD
CURRENT
IL(A)
TERMINA
L
VOLTAGE
v
ARMATURE
CURRENT
Ia(A)
Eg=v+I
a(Ra+R
f)
1 0.35 0 160 0.35 160.04
9
2 0.21 1 94 1.21 94.17
3 0.17 2 76 2.17 76.30
4 0.15 3 68 3.15 68.44
5 0.13 4 60 4.13 60.58
6 0.11 5 52 5.11 52.71
LONG SHUNT DIFFERENTIAL COMPOUND

10. S NO FIELD
CURREN
T
If(A)
LOAD
CURRENT
IL(A)
TERMINA
L
VOLTAGE
v
ARMATURE
CURRENT
Ia(A)
Eg=v+I
a(Ra+R
f)
1 0.35 0 174 0.35 174.04
9
2 0.36 5 175 5.36 175.75
3 0.37 8 177 8.37 178.17
4 0.38 11 179 11.38 180.59
5 0.39 14 182 14.39 184.02
6 0.40 17 186 17.40 188.44
LONG SHUINT CUMLATIVE COMPOUND

11. MEASUREMENT OF Ra:
S NO Va Vf ARMATUR
E
CURRENT
(I)
Ra=Va/I Rf=Vf/I
1 1.2 0.5 11 0.109 0.045
2 2.6 0.9 25 0.104 0.036
AVERAGE 0.1 0.0405

14. RESULT:
By conducting load test the performance
characteristics of DC compound generator were
obtained.

15. Thank you