Features of flexible AC transmission line:-
1. FACTS increase the reliability of AC grids.
2. It controls the voltage under various load condition
3. It balance reactive power (both lagging and leading reactive power)
4. It improves power quality
5. It increases transmission efficiency
6. It also help to solve technical problems in the interconnected power system.
7. They reduce power delivery costs.
8. There is fast voltage regulation.
9. Increased power transfer over long AC lines.
10. Better utilization of the network,
11. Increased availability and reliability
12. As well as improved network stability are achieved along with higher supply quality.
* In conventional AC transmission system the ability to transfer AC power is limited due to various reasons.
* So the actual amount of power transferred to the load (active power) is always less than apparent power.
* For ideal transmission, the active power should be equal to apparent power.
* The main purpose of facts to obtain active power nearly equal to apparent power by supplying lagging reactive power or leading reactive power as per requirements.
* For this, FACTS uses static power electronics devices for series & shunt compensation automatically as per requirements.
Types of FACTS controller:-
Examples of FACTS for series compensation :-
1. Thyristor-controlled series reactor (TCSR)
2. Thyristor-controlled series capacitor (TCSC)
Examples of FACTS for shunt compensation:-
1. Static synchronous compensator (STATCOM)
2. Static VAR compensator (SVC)