Load Balancing: Introduction-brief discussions on Transmission line theory, use of Voltage source inverter (VSI) for reactive power support, mid-point series and shunt compensation and HVDC.
Discussion on voltage profile at the point of common coupling (PCC), need for load compensation, load balancing using passive elements.
Limitations of load balancing using passive elements, Use of VSI as a Var generator, Indirect current controlled synchronous link converter Var Compensator (SLCVC).
Various PWM techniques: Harmonic Elimination and space vector PWM techniques - Theory and implementation issues.
Discussion on bi-directional power flow in VSI, Use of VSI as active filter cum Var generator, Current controlled SLCVC, Strategy-1: Sensing the compensator current, Strategy-2: Sensing the source current, Use of two VSIs, one as Var generator and another as active filter.
Limitations of 2-level VSI, Discussion on the need for the change in power circuit configuration of 2-level VSI for high power application, introduction to multi-level inverters. Principle of operation of 3-level and 4-level diode clamped multi-level inverters. Space vector representation of 3-level VSI, voltage control of 3-level inverter.
Instantaneous reactive power theory, expression for active and reactive powers in terms of d-q components. Reactive power compensator using instantaneous reactive power theory, stationary to rotating frame transformation. Reference wave generation (hardware method), harmonic oscillator, Phase locked loop (PLL) Introduction on one cycle control, discussion on one cycle controlled Var generator and active filter.
Shunt Compensation: Introduction, methods of Var generation: Thyristor controlled reactor (TCR), Thyristor switched capacitor (TSC), Fixed capacitor-Thyristor controlled reactor (FC-TCR), STATCOM.
Series Compensation: Introduction, comparison between series and shunt compensation. Various Equipment: GTO Controlled Series Capacitor (GCSC), Comparison of TCR and GCSC, Thyristor Switched Series Capacitor (TSSC), Thyristor Controlled Series Capacitor (TCSC). Static Synchronous Series Compensator (SSSC), modes of operation, Voltage regulator and Phase Angle Regulator (PAR).
Multi functional FACTS controller: Unified Power Flow Controller (UPFC), control capabilities of UPFC, 2-port representation of UPFC.
HVDC: Introduction, various possible HVDC configurations, unipolar and bipolar links, components of HVDC system: Converter, transformer, smoothing reactor, harmonic filter. Reactive power support, operation of 6-pulse controlled rectifier in inverting mode of operation. Effect of source inductance, equivalent circuit representation of 6-pulse converter considering effect of source inductance. Operation of 12- pulse converter.
Control of HVDC system, Rectifier and inverter characteristics, mode stabilization, current control, voltage dependent current order limit, combined rectifier-inverter characteristics, valve blocking and by-passing, limitations HVDC system using line commutated converters, modern HVDC system - HVDC light.