Control Lab experiment EEP301, 5th sem electrical engineering @ IIT Delhi

1. EEP301 LAB REPORT
SYNCHRO: POSITION
CONTROL
SUBMITTED BY:
Aastha Dua (2009EE5 )
Akshay Gupta (2009EE5 )
Indra Bhushan (2010EE50548)
Kumar Saurav (2009EE5 )
Mehul Mittal (2010EE50553)
Umang Gupta (2010EE50564)
Vivek Mangal (2010EE50566)

2. SYNCHRO:POSITION CONTROL
OBJECTIVE:
 Measurement of Transmitter Output
 Determination of Transmitter Electrical Zero
 Measurement of Transformer Output
 Determination of Transformer Electrical Zero
INTRODUCTION:
A synchro is a type of rotary electrical transformer that is used for measuring the angle of a
rotating machine such as an antenna platform. In its general physical construction, it is much
like an electric motor. The primary winding of the transformer, fixed to the rotor, is excited
by an alternating current, which by electromagnetic induction, causes currents to flow in
three star-connected secondary windings fixed at 120 degrees to each other on the stator. The
relative magnitudes of secondary currents are measured and used to determine the angle of
the rotor relative to the stator, or the currents can be used to directly drive a receiver synchro
that will rotate in unison with the synchro transmitter.
TRANSMITTER TRANSFORMER
Synchro System

3. OBSERVATION:
Measurement of the transmitter output
There is 180 degree phase shift at each zero crossing.

4. Determination of Transmitter Electrical Zero
Rotor Shaft
position θ0
Output Vpk-pk
S2-S1 S3-S2 S1-S3
210 0.24 36.0 35.2
240 22.8 18.4 40.8
270 36.8 4 33.6
300 40.8 23.2 18.0
330 33.6 36.8 3.20
0 18.0 41.6 23.2
30 3.20 37.4 36.8
60 23.2 17.6 40.8
90 36.8 4 34.4
120 40.8 23.2 18.4
150 33.6 36.8 3.20
180 18.8 41.6 22.4

5. The Phase Difference between the two zero output for all the voltage outputs
deduced from above plot is 180ο
. And also note that the phase difference
between minima points in two different phases is 60 ο
.

6. S2-S1 = zero & S3-S2 peak to peak voltage is plotted.
Measurement of Transformer Output
Plot of Transformer output.

7. Determination of Transformer Electrical Zero
Transmitter Shaft Position(degrees) Transformer output R1R2 pk-pk
0 10.9
20 8.24
40 5.04
60 0.88
80 3.36
100 7.04
120 9.92
140 11.5
160 11.8
180 10.7
200 8.24
220 4.80
240 0.8
260 3.44
280 6.96
300 9.84
320 11.6
340 11.8
The transformer zeroes are at 60 ο
and 240 ο
(minima pts.)

8. Direct Drive synchro positioning system:
The rest position of STR150R dial is at 160 when moved by an angle of 5 ο
Also the STR150R dial do not comes to rest when moved by 5 ο
when moved by 10 ο
return
back. Also when ST150T is rotated the other dial rotates and dead band is about 35 ο
.