Synchronous condenser

A synchronous condenser is fundamentally a synchronous motor that is not attached to any driven equipment. It is started and connected to the electrical network. It operates at full leading power factor and puts VARs onto the network as required to support a system’s voltage or to maintain the system power factor at a specified level. The condenser’s installation and operation are identical to large electric motors.

Increasing the devices field excitation results in its furnishing magnetizing power (kilovars) to the system. Its principal advantage the ease with which the amount of correction can be adjusted.

A synchronous condenser provides step-less automatic power factor correction with the ability to produce up to 150% additional MVARs. The system produces no switching transients and is not affected by system electrical harmonics (some harmonics can even be absorbed by synchronous condensers). They will not produce excessive voltage levels and are not susceptible to electrical resonances. Because of the rotating inertia of the condenser, it can limited provide voltage support during a short power outages.

The use of rotating synchronous condensers, was common through the 1950s, however they are now making a comeback as an alternative (or a supplement) to capacitors for power factor correction because of problems that have been experienced with harmonics causing capacitor overheating and catastrophic failures. Synchronous condensers are also very good for supporting voltage in situations such as starting large motors,or where power must travel long distances from where it is generated to where it is used, as is the case with power wheeling (distribution of electric power from one geographical location to another within an electric power distribution system.)