Swinburne
Test
The DC
series motor never starts on no load. As the Swinburne test is no load test
therefore it is not performed on DC series motor.
Describe
the advantages and disadvantages of Swinburne test.
Advantages
As it is a not load test, input power required for higher rating machine is small. The efficiency can find out at any load condition.
Disadvantages
As it is no
load test, the effect of armature reaction and iron losses are not considered
from no load to full load condition. The commutation condition and temperature
rise do not know at full load condition. The effect of rise in the temperature
on shunt field resistance is not considered.
Why
Hopkinson test is also called as regenerative test?
Hopkinson
test as regenerative test
The two
shunt machines in the Hopkinson test are connected in parallel and output of
the first machine (Motor) is given to the input of the second machine
(Generator). The output of the second machine feedback to input of the first
machine therefore it is also called as regenerative test.
How field
current is deciding factor in the Hopkinson test for machine runs as a motor or
generator?
Stronger
field: Generator
Weaker
field: Motor
There are
two same rating shunt machines required in the Hopkinson test. Whether the
efficiency of both machines is same or different? Why?
Hopkinson
Test
The two
shunt machines in the Hopkinson Test are used and the efficiency of the both
machines are not same because of armature current and shunt field current are
not same in both machines.
Why field
test is not called as regenerative test?
Field test
The field
test is applicable only for pair of series machines. The output of the first
machine in this test is given to the input of the second machine and output of
the second machine is dissipated in the load resistance. The output of the second machine is not feed
back to the input of the input machine therefore field test is not called as
regenerative test.
Why the
iron losses and mechanical losses are same for pair of series machines in the
field test?
Field test
The field
winding of pair of the series machines in the field test is connected in series
and both machines are run at same speed therefore the iron losses and
mechanical losses are same in the field test.
You may also like :
No comments:
Post a Comment