Comparison between parallels and series FACTS devices on static voltage stability using MLP index

Determining maximum loading margins is an important issue in power system operation, as system operators must take proper preventive actions to avoid stability problem. This paper presents a study of parallel FACTS devices and series FACTS devices on steady-state voltage and power stability. Their steady state modeling and effects on power system performance have been studied. It also studies static stability improvement of the power system and hence power flow improvement in the network. Effects of FACTS on system loadability have been discussed and presented here. A method based on the concept of maximum loading point index has been used to compare FACTS devices. The study has been carried out on the IEEE 14 bus test system. The line power transfer capability and loadability of the system and therefore, the stability of the system is increased. It has also been observed that for the improvement of these parameters, the parallel FACTS devices are more adequate than the series FACTS devices.