The FACTS about Power Quality

The 21st century’s biggest energy challenge is delivering electricity to the end users with the lowest losses possible while maintaining a high quality level. For older networks, equipment and transmission losses can be very high and network managers need quick return-on-investment solutions to improve quality and increase capacity..


Alstom Grid offers its customers solutions to save energy and to improve power quality by reactive power compensation and harmonic filtering.  


Power electronics-based equipment, including the Flexible AC Transmission System (FACTS), provides proven, dynamic and cost-effective solutions to address these new operating challenges. 

FACTS high-voltage AC transmission solutions are widely recognised by network suppliers and industrial energy managers. Grid operators can gain accurate control of reactive network power, maximise power flow along existing lines and improve steady-state and dynamic stability with the system. 

Flexible AC Transmission System (FACTS) technologies provide the customer with a flexible solution that has minimal infrastructure investment, low environmental impact and rapid implementation time. 

Alstom Grid’s FACTS expertise  

• Evaluation to installation
• Feasibility studies
• Turnkey systems
• Studies and project management
• Power electronic valves, 125 mm - 8.5 kV devices
• Full digital control based on high performance controller
• Installation, commissioning and testing
• Training and maintenance. 

Innovative products 

As one of the world’s leading providers of grid solutions and a global leader in power electronics, Alstom Grid has developed a range of cost-effective solutions to ensure optimal power quality and security. Power quality optimisation means asset utilization maximisation, enhanced service quality and reduced operating costs. Our comprehensive portfolio of FACTS devices is dedicated to enhancing the power quality and performance of our customers’ high-voltage AC transmission systems around the world.

Alstom Grid FACTS solutions include:




MSCDN (Mechanically Switched Capacitors with Damping Networks): proven technology to provide a switchable source of reactive power to stabilize low frequency voltage variations. 


Fixed and Relocatable SVCs (Static VAr Compensators): dynamically variable sources of reactive power to stabilise the voltage, damp system instabilities and reduce flicker for both transmission and industrial applications.



STATCOM: highly dynamic voltage source converter-based compensators which, compared to SVCs, offer improved range of operational voltage, a faster response and a smaller site area.  



FSC (Fixed Series Capacitors): switchable banks of capacitors inserted in series with a line to compensate for the inductive voltage drop, effectively increasing the line length. 



TCSC (Thyristor Controlled Series Capacitors): similar to FSCs but provide dynamic power flow controllability and can mitigate the effects of sub-synchronous resonance.