Basic types of facts controllers

Basic types of facts controllers

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  Basic Types ofFACTS Controllers Presented by T.S.L.V.Ayyarao Assistant Professor GMRIT
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  Basic Types ofFACTS Controllers FACTS controllers are classified as  Series Controllers  Shunt Controllers  Combined Series-Series Controllers  Combined Series-Shunt Controllers
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  Basic Types ofFACTS Controllers Series Controllers:  It could be a variable impedance (capacitor, reactor, etc) or a power electronic based variable source of main frequency, subsynchonous and harmonic frequencies to serve the desired need.
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  Basic Types ofFACTS Controllers Series Controllers:  Inject a voltage in series with the line.  If the voltage is in phase quadrature with the current, controller supplies or consumes reactive power.  Any other phase, involves control of both active and reactive power.
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  Basic Types ofFACTS Controllers Shunt Controllers:  It could be a variable impedance (capacitor, reactor, etc) or a power electronic based variable source or combination of both.
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  Basic Types ofFACTS Controllers Shunt Controllers:  Inject a current in the system.  If the current is in phase quadrature with the voltage, controller supplies or consumes reactive power.  Any other phase, involves control of both active and reactive power.
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  Basic Types ofFACTS Controllers Combined Series-Series Controllers:  It could be a combination of separate series controllers or unified controller.
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  Basic Types ofFACTS Controllers Combined Series-Series Controllers:  Series controllers supply reactive power for each line and real power among lines via power link.  Interline power flow controller balance real and reactive power flow in the lines.
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  Basic Types ofFACTS Controllers Combined Series-Shunt Controllers:  It could be a combination of separate series & shunt controllers or unified power flow controller.
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  Basic Types ofFACTS Controllers Combined Series-Shunt Controllers:  Inject current into the system with the shunt controller and voltage in series with the line with series controller.  When the controllers are unified, exchange real power between series and shunt controllers via power link.
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  Basic Types ofFACTS Controllers Choice of the controller:  Series controller controls the current/power flow by controlling the driving voltage.  To control current/power flow and damp oscillations, series controller is several times more powerful than shunt controller.  Shunt controller injects current in the line  Thus it is used for more effective voltage control & damp voltage oscillations.
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  Basic Types ofFACTS Controllers  Injecting the voltage in series with the line can improve the voltage profile.  But shunt controller is more effective to improve the voltage profile at substation bus.  For a given MVA, size of series controller is small compared to shunt controller.  Shunt controllers cannot control the power flow in the lines.  Series controllers should bypass short circuit currents and handle dynamic overloads.
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  Basic Types ofFACTS Controllers  Controllers with gate turn off devices are based on dc to ac converters and exchange active/reactive power with ac lines.  This requires energy storage device.
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  Basic Types ofFACTS Controllers  Energy storage systems are needed when active power is involved in the power flow.  A controller with storage is more effective for controlling the system dynamics.  A converter-based controller can be designed with high pulse order or pulse width modulation to reduce the low order harmonic generation to a very low level.  A converter can be designed to generate the correct waveform in order to act as an active filter.