Renewable energies, such as wind and solar energy, are the solution to many of our problems, but they also introduce challenges. Synchronous condensers (SCs) are the answer to loss of inertia and short-circuit power. Equipped with ABB’s AC500 Programable Logic Controllers (PLCs) and variable speed drives (drives) to ensure reliable and safe operation, ABB’s synchronous condensers support power grids all over the world. ABB joins the Faroe Islands in their fight against climate change.
Future-proof energy supply and a stable power grid
With a target as challenging as 100% clean energy production by 2030, the Faroe Islands’ government and public energy company SEV have their work cut out for them. Especially considering their power grid isn’t connected to any other countries. This leaves their electrical grid vulnerable and in constant need to be stabilized. Luckily, they have modern companies to support them with the necessary equipment – ABB is one of them. With three ABB synchronous condenser units deployed, the Faroe Islands have hit the milestone of 50% clean energy production in 2023.
ABB Large Motors and Generators division provides synchronous condensers
ABB Large Motors and Generators division is based in Västerås, Sweden, and focuses on producing large, synchronous machines, generators, and control cabinets. Recently, the synchronous condenser also joined their extensive portfolio of products. The division is known for its extraordinarily efficient machines. In 2017, they set the world record in energy efficiency with their 99,05% energy-efficient synchronous motor.
Synchronous condensers and their role in power grids
A flexible and reliable power grid is indispensable. But expanding the grid with renewable energies can reduce stability. Traditionally, fossil-fuel-powered turbines have provided vital spinning inertia and short-circuit power to keep the grid stable. But now, those turbines are being decommissioned and replaced by inverters that lack rotating mass and the capability to support the grid with short-circuit power. A lack of spinning inertia and short-circuit power can cause fluctuations in frequencies and make the energy grid more vulnerable to disturbances.
To mitigate the challenges, attention has turned to synchronous condensers. They provide inertia, reactive power, and short circuit power to boost frequency and voltage stability and strengthen the power grid. One synchronous condenser adds up to 100MWs of inertia which can be further increased with a flywheel, adding up to a total inertia of up to 465 MWs.
Application layout of a synchronous condenser with AC500, CP600 and SCADA application (Source: ABB MOLM). 
Overview of a synchronous condenser, including its cooling plant (Source: ABB MOLM). 
The synchronous condenser (SC) is started by a pony motor mechanically coupled to the SC. The pony motor accelerates the SC to nominal speed during startup (Source: ABB MOLM). 
The cooling system ensures optimal cooling of all machine parts at all times through its extensive network of cooling pipes (Source: ABB MOLM).
AC500 PLC in synchronous condenser applications
ABB's Large Motors and Generators division has used the AC500 PLCs and CP600 HMI panels for many years in their synchronous motor and generator projects. As many machines and generators are often included in critical applications, reliability is crucial. That is why the AC500-S Safety and AC500 High Availability redundancy concept is often employed.
Broadly speaking, the synchronous condenser uses the same technology as the synchronous motor but with a different control system. Due to its flexibility and reliability, the AC500 PLC is the perfect solution for the control system of the new synchronous condenser. Additionally, ABB developed a flywheel that adds rotational mass to the SC.
The synchronous condenser is started by a pony motor mechanically coupled to the SC’s flywheel. The pony motor is a low voltage induction motor controlled by an ABB ACS880 variable speed drive, which accelerates the SC to a nominal speed during startup. The AC500 manages the ACS880 drive and oversees the safety and performance of the pony motor.
Furthermore, the AC500 PLC monitors and protects the flywheel, the lubrication, jacking oil, and the cooling system. It also supervises and controls the entire system environment, including auxiliary equipment and subsystems, even during standstill. The PLC interacts with the Automatic Voltage Regulator (AVR), which controls the excitation and synchronization functionality of the synchronous condenser and provides excitation protection functionality. The AC500 also handles communication to customer SCADA/DCS systems for remote control and supervision via various available protocols, including Modbus TCP/IP and DNP3.
The CP600 HMI panels replace all traditional buttons. They provide a clean and user-friendly interface and show operators all relevant values for monitoring. Like this, the commissioning engineers can receive full support during the installation and startup of the SC. The synchronous condenser cooling system is equipped with its own AC500-eCo PLC, which is connected to the main AC500 in the SC application. This ensures optimal cooling of all machine parts at all times.
Outlook for ABB’s synchronous condenser applications
ABB will continue to deliver synchronous condenser packages to stabilize power grids all around the world. Like this, ABB supports the renewable energy transition as traditional power production is replaced by sustainable alternatives. The synchronous condenser will supply vital inertia to grids that are no longer capable of creating kinetic energy and thus increase flexibility and reliability. Today, ABB SC solutions already exist in Canada, the US, Faroe Island, Australia, and England.
