Here, a hybrid flow controller (HFC) is introduced as a part of the of flexible ac transmission system (FACTS) controllers for steady-state and power-flow control of power transmission lines. The HFC is a hybrid compensator that provides series and/or shunt compensation. The major mechanical components of the HFC are:
-a mechanically switched phase-shifting transformer
- a mechanically switched shunt capacitor
-multimodule, series-connected, thyristor-switched capacitors and inductors

This article describes the steady-state operation, single-phase equivalent circuit, power-flow model, V vs I and P vs Q characteristics of the HFC.
for an interconnected power system, steady state and dynamic power-flow control, particularly under heavily loaded system conditions is a prerequisite. Various FACTS controllers are available in the documentation. The new HFC is discused in the following details:
-steady-state principles of operations
-single-line equivalent circuit and power-flow model is developed
-steady-state power-flow control characteristics is investigated

PRINCIPLES OF OPERATIONS OF HFC
An HFC is comprised of:
-a PST capable of injecting a lead/lag, quadrature-phase voltage
-multimodule TSSC system which can insert a variable series capacitive reactance, in discrete steps.
-multimodule TSSR system which is capable of inserting a variable series
inductive reactance, in discrete steps.

Get the report here:
http://mediafirefile/7s9hexnv7cd1s4v/HFC.pdf