Answer Posted / abhi
Hopkinson's test is another useful method of testing the efficiency of a dc machine. It is a full load test and it requires two identical machines which are coupled to each other. One of these two machines is operated as a generator to supply the mechanical power to the motor and the other is operated as a motor to drive the generator. For this process of back to back driving the motor and the generator, Hopkinson's test is also called back-to-back test or regenerative test.
If there are no losses in the machine, then no external power supply would have needed. But due to the drop in the generator output voltage we need an extra voltage source to supply the proper input voltage to the motor. Hence, the power drawn from the external supply is therefore used to overcome the internal losses of the motor-generator set.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
what is the standard duration after failure EB power
Can an inverter be used as a converter? How?
What should be current in the Primary and secondary side of 1000KVA (11KV Supply)Transformer.?
Dear Brother can u tell the proper size selection of cable & the fault level calculation of braker, busbar etc. pls mail me at azeemk30@gmail.com
Is electro plating what type of load whether resistive, inductive or capacitive loads
What is FTA card? How it works?
what is the importance of earthing system on the generators big capacity and small?
how to select electrical equipment such as fuse,dg,transformer,motor,msb,wire,cable as per the connecting load..please mention any books to design,take licence
what work will do diffrential realay DG set
what is the meaning of 0.5ohm Resistance
How will calculate losses in an multi core Aluminium LT cable of different sizes & upto what length we can use a LT Cable ?
Approach of a cooling tower is the difference between temperatures of what factors?
What is the tension required for the 25000 CFM AHU belt
WHY DO VOLTAGE TRANSFORMERS FAIL DURING EARTH FAULT IN THE DELTA CONNECTED 6.6KV ELECTRICAL SYSTEM
we need a ntpc previous papers
