When used without mechanical output, synchronous motors are referred to as what type of condenser?

Synchronous motors that operate without mechanical output are commonly referred to as synchronous condensers. These devices are used primarily for power factor correction in electrical systems. They can adjust the reactive power in a circuit, thereby improving the overall efficiency of the power system.

When synchronous motors are overexcited, they generate reactive power (VARs), which can be used to counteract inductive loads in the system. This helps in maintaining voltage levels and stabilizing the grid. Additionally, synchronous condensers are capable of providing voltage support and enhancing system reliability during periods of high demand or during disturbances in power quality.

The other options presented clarify why they do not apply. For instance, a parallel condenser typically refers to capacitors that are connected in parallel with a load to provide power factor support. A static condenser could refer to a fixed capacitor setup that does not include the dynamic capability of a synchronous motor. Capacitive condenser is not a standard term used in the context of synchronous motors and their applications. Thus, synchronous condenser is the most accurate term for describing the specific function of these motors when they are used to improve power quality without delivering mechanical output.