Correct Answer - Option 1 : Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I
In general, there are two situations in which compensation is required.
- In the first case, the system is absolutely unstable, and the compensation is required to stabilize it as well as to achieve a specified performance.
- In the second case, the system is stable, but the compensation is required to obtain the desired performance.
The systems which are of type-2 or higher are usually absolutely unstable. For type-2 or higher systems, only the lead compensator is required because only the lead compensator improves the margin of stability.
Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I
Note: In type-1 and type-0 systems, stable operation is always possible if the gain is sufficiently reduced. In such cases, any of the three compensators, lead, lag, lag-lead may be used to obtain the desired performance.