Flexible AC transmission system

The term Flexible AC Transmission System (in German: flexible three-phase transmission system ), abbreviated to FACTS , comprises several control systems in electrical power engineering that are used in power supply networks for the targeted influence of power flows . Power electronics components , similar to high-voltage direct current transmission (HVDC), are used as an essential property . The power electronics are not used to transmit energy using direct current; rather, it serves to influence power flows in three-phase AC networks without rotating machines .

The term is defined by the IEEE as static power electronics that specifically influence electrical parameters for power transmission in one or more AC voltage networks in order to be able to optimally utilize the transmission capacities .

General

The control of power flows can be carried out in meshed AC voltage networks by changing the reactive and active powers using capacitor batteries or compensation coils on the tertiary windings of power transformers . This corresponds to a parallel compensation (English Shunt Compensation ). Furthermore, power flows can be changed by means of a series compensation, for example by means of a phase shift transformer . Another, limited option is to modify the rotor angle on the synchronous generators used to generate electricity directly in the power plant . There are also possibilities to vary voltages within limits using step switches in the power transformers.

FACTS includes methods for load flow control and network stabilization in electrical energy networks by means of power electronics, whereby the electronics are used directly in an area of the power flow and are not only used for control and regulation technology . The power electronics have the advantage of being able to react to changes almost wear-free and without inertia. The associated high technical effort and the associated higher costs are disadvantageous. The Flexible AC Transmission Systems division includes:

Static Synchronous Compensator (STATCOM), an electronic unit for parallel compensation of capacitive or inductive reactive power.
Unified Power Flow Controller (UPFC) represents the most functional electronic system. The UPFC can be used for parallel as well as series compensation of capacitive or inductive reactive power and for the targeted control of active power flows in high-voltage lines. Furthermore, in certain areas the natural performance of overhead lines can be changed and unbalanced loads can be compensated.

literature

Xiao-Ping Zhang, Christian Rehtanz, Bikash Pal: Flexible AC Transmission Systems: Modeling and Control . Springer, Berlin 2005, ISBN 978-3-540-30606-1 .
Narain G. Hingorani, Laszlo Gyugyi: Understand FACTS: Concepts and Technology of Flexible AC Transmission Systems . IEEE Press, 2000, ISBN 978-0-7803-3455-7 .

Web links

FACTS - Flexible three-phase transmission systems. ABB company website
Siemens Flexible AC Transmission Systems (FACTS). Siemens AG, Energy Sector company website

Individual evidence

↑ IEEE (Ed.): Proposed terms and definitions for flexible AC transmission system (FACTS) . 4th edition edition. tape 12 . IEEE Transactions on Power Delivery, 1997, p. 1848-1853 , doi : 10.1109 / 61.634216 .

[ieee1997-1] IEEE (Ed.): Proposed terms and definitions for flexible AC transmission system (FACTS) . 4th edition edition. tape 12 . IEEE Transactions on Power Delivery, 1997, p. 1848-1853 , doi : 10.1109 / 61.634216 .