# EE 1203 ELECTRICAL MACHINES LABORATORY – I

EE 1203 ELECTRICAL MACHINES LABORATORY – I

0 0 3 100*

AIM

To expose the students to the operation of D.C. machines and transformers

and give them experimental skill.

1) Open circuit and load characteristics of D.C separately and self

excited shunt generator

2) Load characteristics of D.C. compound generator with differential

and cumulative connection

3) Load characteristics of D.C. shunt and compound motor

4) Load characteristics of D.C series motor

5) Swinburne's test and speed control of D.C shunt motor

6) Hopkinson's test on D.C motor – generator set

7) Load test on single-phase transformer and three phase transformer

connections

8) Open circuit and short circuit tests on single phase transformer

9) Sumpner's test on transformers

10) Separation of no-load losses in single phase transformer

* P = 45 Total = 45*

Detailed Syllabus

*1. **Open Circuit and Load Characteristics of DC

Separately and self excited shunt Generator*

* *

Aim

To conduct no load and load test on self and separately excited generators

and obtain the characteristics.

* Exercise*

1. Obtain the open circuit characteristics of a separately

and self excited D.C generator and determine critical resistance.

2. Draw the external and internal characteristics of a

separately and self excited D.C generator and compute full load regulation.

*2. **Load Characteristics Of D.C. Compound Generator with

differential and cumulative connection*

*Aim*

To conduct load test on DC compound generator and obtain the load

characteristic curves

* Exercise*

1. Obtain the following curves for cumulative, differential

and shunt generator

a. IL Vs V for DC cumulative compound generator

b. IL Vs V for DC differential compound generator

All graphs should be drawn on the same graph sheet

*3. Load characteristics of DC Shunt and compound motor*

*Aim*

To conduct load test on DC shunt motor and compound

motor and draw the

characteristic curves

Exercise

1. Draw the following characteristic curves for DC shunt

and compound motor

a. Output Vs ?%

b. Output Vs T

c. Output Vs N

d. Output Vs IL

e. Torque Vs N

*4. Load characteristics of DC series motor*

Aim

To conduct load test on DC series motor and draw the

characteristics curves

Exercise

1. Draw the following characteristics curve for DC series motor

a. Output Vs ?%

b. Output Vs T

c. Output Vs N

d. Output Vs I

e. Torque Vs N

*5. **Swinburne**'s Test and speed control of DC shunt

motor*

* Aim*

To conduct Swinburne's test and predetermine the performance characteristics

of DC machine and speed control of DC motor

Exercise

1. Predetermine efficiency at various load current while

operating as a motor and generator and plot a graph output Vs ?%

2. Draw the following curves for

a. If Vs N at Va = 0.8 Va and Va

b. Va Vs N at 0.8 If and If

*6. Hopkinson's Test on DC motor – Generator set*

Aim

To conduct Hopkinson's test on a pair of DC shunt

machines and determine their

efficiency.

*Exercise*

1. Determine the stray losses of the machines.

2. Obtain efficiency curves for the motor and generator and

draw the curves.

*7. Load Test On Single-Phase Transformer and three phase

transformer connections*

Aim

To conduct load test on the given single phase transformer and

determine its

Performance.

*Exercise*

1. Draw the following graph for single phase transformer

a. Output Vs ?%

2. To carry out the following three phase transformer

connection

Y-Y; Y-?; ? – ?; ? – Y

Check the input output voltage ratio for various three phase connection.

* *

*5. **Open Circuit and Short Circuit Tests on Single Phase

Transformer*

Aim

To conduct O.C and S.C test on a single phase

transformer and calculate the

performances

Exercise

1. Determine the equivalent circuit of the transformer.

2. Predetermine the efficiency at different load at UPF and

0.8 Power factor lagging.

3. Predetermine the full load regulation at different power

factor.

4. Draw the following curves

a. Output Vs ?%

b. Power factor Vs %Regulation

*6. **Sumpner's Test on transformers*

Aim

To conduct Sumpner's test on a pair of identical

single phase transformers and

predetermine performance.

*Exercise*

1. Study the paralleling process for two identical

transformers.

2. Determine the equivalent circuit parameters of each

transformer.

3. Predetermine the efficiency at different loads at 0.8

and 1.0 power factors.

4. To predetermine the full load regulation for different

power factors.

5. Draw the following graph

a. Output Vs %?

b. Power factor Vs %Regulation

*7. **Separation of No-Load Losses in Single Phase

Transformer*

Aim

To separate the iron losses of a single phase

transformer into its components

a. Hysterisis losses

b. Eddy current losses

*Exercise*

1. Separate the no load losses into hysterisis and eddy

current components.