A stable grid in the era of renewables

Synchronous condenser

Parallel connected synchronous condensers are mainly used for providing short-circuit power and inertia. They also help to stabilize the network through voltage recovery during faults. This becomes increasingly important with the rising share of renewable power generation that leads to a lack of short-circuit power and inertia. Due to the fact that conventional power plants are shut down, synchronous condenser solutions use a conventional generator to provide the necessary inertia and short-circuit contribution by means of its rotating mass while also providing or absorbing reactive power.

Synchronous condenser at a glance

Proven solution to stabilize the grid

A synchronous condenser provides short-circuit power, inertia, and reactive power for dynamic loads. Siemens supplies a broad range of generators up to 1,300 MVA at full speed.

Inertia and short-circuit power are key elements of grid stability – yet their availability is shrinking. This is caused by 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. All of this influences the stability of transmission networks, resulting in a worldwide renaissance of the synchronous condenser. The Siemens synchronous condenser solution comprises a horizontal synchronous generator connected to the high-voltage transmission network via a step-up transformer. It is started up and stopped with a frequency-controlled electric motor (pony motor) or a starting frequency converter. When the generator has reached operating synchronous speed, it will be synchronized with the transmission network, and the machine is operated as a motor providing reactive and short-circuit power to the transmission network.


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Our solutions in practice

Many of our products and solutions are already being successfully used. Below is an example of these applications.

Be in control

Paving the way for renewables

With the rise of renewable power generation and the retirement and shutdown of thermal power plants, synchronous condensers have to take over the part of providing enough inertia and short-circuit power. At Siemens, we provide tailor-made turnkey synchronous condenser solutions up to 1,300 MVA to address our customers’ needs based on proven, reliable in-house equipment, extensive know-how of transmission system requirements, and project execution experience.