A flexible alternating current transmission system (FACTS) is a system composed of static equipment used for the alternating current (AC) transmission of electrical energy. It is meant to enhance controllability and increase power transfer capability of the network. It is generally a power electronics-based system.
Flexible Ac Transmission System Ppt Pdf
FACTS is defined by the Institute of Electrical and Electronics Engineers (IEEE) as "a power electronic based system and other static equipment that provide control of one or more AC transmission system parameters to enhance controllability and increase power transfer capability".[1]
According to Siemens, "FACTS Increase the reliability of AC grids and reduce power delivery costs. They improve transmission quality and efficiency of power transmission by supplying inductive or reactive power to grid.[2]
The worldwide power sector has witnessed significant disruption, growth, and change in recent years. Siemens Energy has developed modern, flexible, high capacity grid stabilizing solutions. Read more in our new brochure!
The addition of renewables-based power generation to the energy mix, phase-out of thermal power plants, new HVDC systems, and the extension of power supply systems to remote areas influence the stability of transmission networks.
Power producers and system operators are faced with increasing demands for bulk power transmission, low-cost power delivery, and high system reliability. At the same time, bottlenecks cause limitations in power transmission. For highly dynamic load compensation in the industry a very fast compensation system is called for.
The innovative SVC PLUS for Reactive Power Compensation is a cost efficient, space saving, flexible solution to increase dynamic stability and power quality of the grid, based on multilevel Voltage-Source Converter (VSC) technology.
As the infeed of power from renewable sources continuously replaces conventional synchronous power generation, the grid frequency is getting more sensitive due to the reduced amount of rotating machines. Now grid operators are faced with the challenge to provide sufficient system inertia of synchronous generators with high rotating masses to stabilize the grid.
An SVC PLUS Frequency Stabilizer can solve this challenge as it is able to emulating system inertia by boosting high active power into the grid when needed. In addition it offers voltage support by means of reactive power compensation.
Mechanically switched devices (MSC/MSCDN) are the most economical reactive power compensation devices. MSCs are a robust solution for voltage control and network stabilization under steady state conditions. The MSCDN additionally offers a damping network to avoid resonance conditions in the electrical system.
The fixed series capacitor (FSC) is part of the series compensation portfolio and makes use of capacitors. They provide an increase in transmission system stability and capacity for power transmission.
Decentralized energy systems and the associated uncontrolled power flows pose new challenges for the existing AC grids. Thermal overloads in the lines and a growing number of cases in which frequency and voltage come critically close to acceptable range limits, or even exceed them, threaten grid stability and the transmission infrastructure. The Unified Power Flow Controller (UPFC PLUS) controls power flow in just milliseconds thus stabilizes the AC grid even in critical situations (Grid Code N-1). UPFC PLUS lets you get the most from your existing grid capacity while maintaining maximum protection, reducing the risk of power failures, and minimizing redispatch costs.
Siemens Energy's MVDC PLUS medium-voltage DC solution is a powerful system for managing future distribution grids and regional transmission networks. The solution provides power flow control, long distance transmission, increased feed-in, transmission autonomy and grid connection.
In one of the first interviews of the Transmission Talks series Bernd Niemann, Business Development Manager for FACTS, explains the rising importance of Flexible AC Transmission Systems to stabilize high-voltage power transmission systems. Many transmission operators (TSOs) rely on Siemens-Energy proven FACTS portfolio to keep their grids future-proof. Take advantage of our expertise to learn about new strategies to keep your grids stable.
In order to ensure resilient grids, flexible and quickly deployable systems are required for rapid grid restoration after severe events, for bridging in case of grid changes due to e.g. power plant shutdowns or the integration of renewables as well as for the revision of transmission lines at important nodes. Learn more about our containerized and mobile Flexible AC Transmission Systems:
In three-phase AC grids problems are often caused by temporarily increased load on one phase for example for trains use the transmission system while passing by. Fast and efficient load balancing for each phase is also required in historically developed infrastructures in challenging environments, e.g. for metro stations in megacities.Therefore, utilities require enhanced solutions that combine the advantages of SVC solutions with less space requirements as well as lower noise requirements.Siemens Energy' SVC PLUS with its flexible, modular concept could be the perfect match. The electric characteristics of the SVC PLUS differ from a classic SVC. Its current control leads to a superior undervoltage performance, which means that the SVC PLUS can support the network longer and at lower voltages.
SVC PLUS Frequency Stabilizer stores energy in super capacitors and releases the energy whenever the grid needs it. It therefore avoids frequency drops and enables further renewable power integration to the network. It is a pure power electronic system based on proven SVC PLUS technology.
Synchronous condenser solutions support transmission systems with short-circuit power, reactive power and inertia to stabilize the grids and to prevent blackouts. They feature high efficiency, low noise emissions and low installation and commissioning costs. Inertia can be extended by the use of a fly wheel.
The latest innovation from Siemens Energy for load flow control is the high sophisticated Unified Power Flow Controller (UPFC PLUS) with an additional function for voltage control. It is based on proven converter technology from Siemens Energy just like the MVDC PLUS (Medium-Voltage Direct Current) system which offers load flow control via DC transmission. The passive Fixed Series Capacitors (FSC) offer stability of long-distance transmissions by compensating the inductive reactance. The transmission of active power is mainly limited by the impedance of the transmission line, comprising the ohmic resistance plus the capacitive and inductive reactance. They help to better utilize existing overhead lines by increasing their transmission capacities and contribute to steady state and dynamic stability of the system.
As a solution tuned filter circuits can be applied, carefully selected in accordance with network requirements and can be part of the SVC system. The most advanced approach however for low order harmonics (approx. up to 13th) harmonic is active filtering, a task performed by the very fast SVC PLUS control concept practically as a byproduct and including inter-harmonics.
Generators are three-phase sources of energy that is transported through the grid up to the consumers. The whole system works best when all three phases are evenly loaded. But certain loads are only single phase, and certain three-phase loads can become extremely unsymmetrical in special operating conditions, e.g. an electric arc furnace for melting steel can be anything between balanced up to only two-phase operation at worst.
Compensation systems capable of independent control for each phase, like SVC Classic and SVC PLUS, allow distinct injection of capacitive or inductive power into each phase. In this way symmetric balanced loading of the feeding network can be achieved despite asymmetry in load.
In conventional AC transmission, the power transfer capability has been limited by various dynamic and static limits such as transient stability, voltage stability, thermal limits, etc. These inherent power system limits led to the under utilization of existing transmission sources.
With the invention of thyristor devices, power electronic converters are developed that led to implement FACTS controllers. These power electronic based controllers can provide smooth, continuous, rapid and repeatable operations for power system control.
It is an AC transmission system that incorporates a power electronic controller and other static controllers to improve the controllability as well as power transfer capability. It improves the performance of electrical networks by managing active and reactive power.
The IEEE definition for FACTS controller is stated as , it is a power electronic based system and other static equipment that provides the control of one or more AC transmission parameters (such as voltage, impedance, phase angle and power).
The compensation techniques of the power system supplies the inductive or capacitive reactive power (to its particular limits) in order to improve the quality and efficiency of the power transmission system. The following are the two popular compensation techniques used in power system.
In this type of reactive power compensation, various compensation or FACTS devices (which can be either switched or controlled) are connected in parallel to the transmission lines at particular nodes.
In this, various compensation or FACTS devices (which can be either switched or controlled) are connected in series with the transmission lines at particular nodes. This compensation will give more control of power flow through the line and also improves the dynamic stability limit of the power system.
These controllers inject a current into the system at the point of connection. If this current is in phase quadrature with the line voltage, a shunt controller consumes or supplies variable reactive power to the network. 2ff7e9595c
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