A Thyristor controlled series capacitor (TCSC) is a device which is used to increase the transmission line capacity. The TCSC device furnishes inductive as well as capacitive reactance compensation to alter the power flow of the transmission line. A difficulty is observed on tuning the TCSC device; large change in TCSC reactance ΔX at critical region (nearby resonance region) makes inconvenience for compensating any small change in dynamic demand at load end. This paper presents microtuning of line reactance by implementing split TCSC in place of single TCSC. The Newton Raphson method power flow analysis (NRPFA) is used to examine the fine microtuning of line reactance to compensate the small change in power demand. The mathematical modeling of NRPFA with single TCSC and split TCSC are studied. Comparison of power flow and power loss variation between single TCSC and split TCSC are also examined. Any violation of transmission line loading limits and voltage margin are verified and discussed while inserting TCSC in transmission line. The IEEE 14 bus system, IEEE 30 bus system and WSCC 9 bus system are considered as a case study. © 2012 Elsevier Ltd. All rights reserved.