Final answer:
To find the load taken by each machine and the necessary adjustments, we can use the droop characteristics. Each machine's rated load is 75 MW, and the load taken by each machine at different droop levels can be calculated by subtracting the droop percentage from the rated load. The necessary adjustments would involve increasing the speed of the machine with lower load and decreasing the speed of the machine with higher load.
Step-by-step explanation:
To find the load taken by each machine in parallel, we can use the droop characteristics.
Droop is the change in frequency of a generator when its load changes.
In this case, the droop is 4% at 50% and 75% of the rated load.
First, let's calculate the rated load of each machine.
Since they are identical, their individual rated load would be half of the total load.
The total load is given as 150 MW, so each machine's rated load would be 75 MW.
Next, let's find the droop at 50% and 75% of the rated load. At 50% load, the droop is 4%.
This means that the frequency of each machine will decrease by 4%.
Similarly, at 75% load, the droop is also 4%. Now, let's calculate the actual load taken by each machine at these droop values.
Since the rated load of each machine is 75 MW, the actual load taken by each machine at 50% droop can be found by subtracting 4% of 75 MW from 75 MW.
Similarly, the actual load taken by each machine at 75% droop can be found by subtracting 4% of 75 MW from 75 MW.
Therefore, the load taken by each machine at 50% droop would be 75 MW - (4% of 75 MW) and the load taken by each machine at 75% droop would be 75 MW - (4% of 75 MW).
The adjustments that should be made by the speed changer of the machines to share a load of 150 MW equally would be to increase the speed of the machine with lower load and decrease the speed of the machine with higher load. This would help in balancing the load between the two machines.