Types Of FACTS Controllers Notes

TYPES OF FACTS CONTROLLERS:

 In general, FACTS Controllers can be divided into four categories:

 1. Series controllers

 2. Shunt controllers

 3. Combined series-series controllers

 4. Combined series-shunt controllers
1. SERIES CONTROLLERS:

A series controller could be variable impedance such as capacitor reactor or power electronics based variable source of main frequency, sub-synchronous and harmonic frequencies (or a combination) to serve the desired need. In principle, all series controllers inject voltage in series with the line. Even variable impedance multiplied by the current flow through it represents an injected series voltage in the line.

Different types available are as follows:

            Static Synchronous Series Compensator (SSSC)

       Interline Power Flow Controller (IPFC)

      Thyristor- Controlled Series Reactor (TCSR)

      Thyristor-Switched Series Reactor (TSSR)

       Thyristor-Controlled Series Capacitor (TCSC)
      Thyristor-Switched Series Capacitor (TSSC)

2. SHUNT CONTROLLERS:

In principle all shunt Controllers inject current into the system at the point of connection. Even variable shunt impedance connected to the line voltage causes a variable current flow and hence represents the injection of current into the line.         Different types available are listed below.

• Static Synchronous Compensator (STATCOM).
• Static Synchronous Generator (SSG).
•  Static VAR Compensator (SVC).
•  Thyristor Controlled Reactor (TCR).
•  Thyristor Switched Reactor (TSR).
•  Thyristor Switched Capacitor (TSC).
• Static VAR Generator (SVG).

3. COMBINED SERIES-SERIES CONTROLLERS:       

           This could be a combination of separate series controllers, which are controlled in a coordinated manner in a multi line transmission system. The real power transfer ability of the unified series-series controller , referred to as interline power flow controller, makes it possible to balance both the real and reactive power flow in the lines thereby maximize the utilization of the transmission system.

·         Interline Power Flow Controller(IPFC)

4. COMBINED SHUNT-SERIES CONTROLLER:

          This could be a combination of separate series and shunt controllers, which are controlled in a coordinated manner or UPFC with the series and shunt elements. In principle, combined shunt and series controllers inject current into the system with the shunt part of the controller and voltage in series in the line with the series part of the controller. When series and shunt controllers are unified, there can be a real power exchange between the series and shunt controllers via the power link. Different types are listed below.

·         Unified Power Flow Controller (UPFC).

·         Thyristor-Controlled Phase Shifting Transformer (TCPST).