load test on dc compound generator (long shunt)

WELCOMETHIAGARAJAR COLLEGE OF ENGINEERING (A Govt. Aided, ISO 9001:2008 Certified, Autonomous Institution Affiliated to Anna

University)MADURAI – 625 015Department of Electrical and Electronics Engineering

LOAD TEST ON DC COMPOUND GENERATOR

(LONG SHUNT)

PRESENTED BY,

V.Rajalakshmi -14E87 T.Naveena -14E80R.Priyadharshini -14E85 T.Palani Kumar -14E83 S.P.Nandhini -14E79 P.Prakash -14E84S.Priyanka -14E86 S.Padmanathan -14E82

Dc compound generator

Cumulatively Differential

Long Shunt

Short Shunt

CHARACTERISTICS

Aim:To conduct load test on DC compound generator (long shunt)and to determine itscharacteristics.Internal characteristics – generated emf Vs armature currentExternal 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 24 CARBON

RHEOSTAT50Ω,4.1A 1

5 LOAD (40A,160V) 1

APPARATUS REQUIRED:

NAME PLATE DETAILS:S NO PARAMETERS MOTOR GENERATOR

1 RATED VOLTAGE 230V 160V2 RATED CURRENT 35.7A 38A3 RATED SPEED 1450rpm 1450rpm4 RATED POWER 7KW 6.1KW5 RATED FIELD

CURRENT0.58A 0.58A

FORMULAE USED:Eg = V + Ia (Ra+Rf),Ia =load current+ filed current

Eg = generated emfIa = armature currentRa = armature resistanceRf = series filed resistance

PROCEDURE:1. Make the connections as shown in the figure2. Keep the D.C motor field in minimum position and generator rheostat inmaximum position initially load should not be connected to generator out putterminals and are open circuited.3. Motor started with the help of a 3-point starter and its field regulator is adjustedso that rated speed of motor obtained4. The gen field rheostat is also adjust such that the rated voltage is obtained atthe gen terminals.5. By keeping the gen field excitation constant load is switched on varied in stepsand meters readings are tabulated.6. In each step of load variation readings are taken the motor is running at ratedspeed is achieved by adjusting motor field rheostat variation of load in speed iscontinued till the generator supplies rated current.7. When the current exceeds gen rated current decrease the load to zero and openthe DPST

S NO FIELD CURRE

NTIf(A)

LOAD CURRE

NTIL(A)

TERMINAL

VOLTAGEv

ARMATURE

CURRENTIa(A)

Eg=v+Ia(Ra+Rf)

1 0.35 0 160 0.35 160.049

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

S NO FIELD CURRE

NTIf(A)

LOAD CURRE

NTIL(A)

TERMINAL

VOLTAGEv

ARMATURE

CURRENTIa(A)

Eg=v+Ia(Ra+Rf)

1 0.35 0 174 0.35 174.049

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

MEASUREMENT OF Ra:S NO Va Vf ARMATU

RE CURREN

T(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

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

Thank you