Flexible AC transmission FACTS-Technology and novel control strategies for power system stabilization enhancement

The lingering problem of voltage stabilization, voltage collapse and dynamic voltage stability phenomena and its final severe consequence of Blackouts is emerging as an urgent challenge in the planning and operation of any modern electric utility power systems. The increase in electrical energy utilization from existing power system with requirements of increased security and reliability requires detailed studies of dynamic voltage stability boundaries and mitigative stabilization methods. Voltage stabilization issue in association with several recent rotating blackout incidents throughout the world have given a real impetus for novel research Flexible AC Transmission Systems (FACTS) devices and systems for generation, transmission and distribution systems.; The new generation of FACTS devices are all based on the GTO' s (gate turn off) switching devices and voltage source converter scheme. FACTS devices play a vital role for voltage stabilization, dynamic reactive power compensation, damping electromechanical/tie line oscillations, controlling transmission power flow, damping torsional subsynchronous resonance modes and reducing harmonic instability by improving the AC system power quality. This thesis presents a detailed study of an extensive family of FACTS convener interface devices based on a new 48-pulse voltage source converter VSC model as a building block in Static Synchronous Compensator (STATCOM), Static Synchronous Series Compensator (SSSC). Static Series Capacitor Compensator (SSCC), Active Power Filter (APF) and Tuned Arm Filter (TAF). FACTS devices are all controlled by a number of novel dynamic error driven controllers such as the decoupled (d-q) current controller, auxiliary tracking control, tri loop error driven (PI) controllers such as multi loop stabilization regulators for special low pulse order FACTS devices used in renewable energy system interfacing for (wind, small hydro, photovoltaic, hybrid utilization).; This thesis validates a number of novel dynamic error driven controllers for most FACTS devices typically utilized for voltage stabilization, reactive power compensation, damping electromechanical oscillations, improving power quality, damping SSR torsional oscillations and voltage flicker control. The research work addressed the electric grid power system as well as other dispersed/distributed standalone renewable energy utilization schemes with robust interface strategies.