Answer Posted / half1951wit0202
Hopkinsons test is also referred as the "Regenerative" or
"Back-to-Back" test. Two identical DC machines are
connected parallely, where as the first machine gets supply
from the DC power source, and acts as a motor and is in turn mechanically coupled to the next machine and makes it to run as a generator. The electrical output power from the generator(second machine) is fed to the motor(First machine) and vice-versa. But due to the losses in these two machines the output from the generator and the motors are not sufficient to run each other, hence the losses are to be compensated externally. In the original Hopkinsons' tests this external power supply was made mechanically by an additional motor coupled through belt-drive. However , in the modified Hopkinson's tests , the external power is supplied electrically from the DC power source.
| Is This Answer Correct ? | 37 Yes | 1 No |
Post New Answer View All Answers
defination of lines
What is the minimum underground tank size capacity considered for firefighting purpose?
if the armature current in a dc generator is ac ( sinusoidal ) why doesnt the sjhape af armature mmf a sinusoidal (ni) ? armature mmf in case of a dc machine is triangular.
what types of electrical & mechanical test conducted in switchyard?
Practical condition in 400KV Sub station:- Breaker(open) , isolator(open), Earthing (close) at both end e.g A & B. Now Open A Stn Earthing than Open B stn Earthing (Which have a 50MVA reactor) , AND suddenly show R,Y,B phase 704KV,573KV,118KV respectively. Que is without closing of breaker how it is possible.???? My Whats app No:07621840498 for Further Discussion. Pls experts suggest.
what is RFCT and Insulgard Relay & It's function?
An automatic water heater is an example of which type of control system?
can you plz send l&t aptitude questions if available its urgent plz plz plz
How to design the NGR Resistance
Can a generator runs after getting 1st stator earth fault.
What is synchro?
clarify types of motor operated valves and advantages
i am in need of AC SYNCHRONUS MOTOR 30KW. ANY ONE KNOWS THE MANUFACTURER OF SAME. ALSO MOSFET AC CONVERTER 20KVA CONT.OUTPUT.
What happens if we connect a single phase energy meter in reverse polarity.
Do u know any one? how to find out in motor rated amps? formula?