Question

Which of the following is NOT an advantage of interconnected electrical grid system?
1. The grid system can improve the diversity factor of each generating station connected to the grid.
2. The grid covers a smaller number of consumers than that of an individual generating station.
3. The arrangement can exchange the peak load of a plant.
4. The interconnected grid increases the reliability of power system.

Answer 1

Correct Answer - Option 2 : The grid covers a smaller number of consumers than that of an individual generating station.

The connection of several generating stations in parallel is known as interconnected grid system.

Advantages:

• Exchange of peak loads: The peak load of the power station can be exchanged. If the load curve of a power station shows a peak demand that is greater than the rated capacity of the plant, then the excess load can be shared by other stations interconnected with it i.e. better co-ordination and energy conservation.
• Use of older plants: The interconnected system makes it possible to use the older and less efficient plants to carry peak loads of short durations.
• Ensures economical operation: Sharing of load among the stations is arranged in such a way that more efficient stations work continuously throughout the year at a high load factor and the less efficient plants work for peak load hours only.
• Increases diversity factor: The load curves of different interconnected stations are generally different. The result is that the maximum demand on the system is much reduced as compared to the sum of individual maximum demands on different stations. In other words, the diversity factor of the system is improved, thereby increasing the effective capacity of the system.
• Reduces plant reserve capacity: When several power stations are connected in parallel, the reserve capacity of the system is much reduced. This increases the efficiency of the system.
• Increases reliability of supply: If a major breakdown occurs in one station, continuity of supply can be maintained by other healthy stations.