Mell Why is a synchronous motor sometimes called synchronous capacitor?
Under excitation causes it to operate at a lagging power factor. When the motor is operated at no load with over-excitation, it takes a current that leads the voltage by nearly 90 degrees. Thus, it behaves like a capacitor and under such operating conditions, the synchronous motor is called a synchronous capacitor.
What is meant by a synchronous capacitor and what is it used for?
A synchronous motor running without mechanical load and drawing a large leading current, like a capacitor; used to improve the power factor and voltage regulation of an alternating-current power system.
What is a synchronous capacitor state its application?
A synchronous condenser (also called a synchronous capacitor or synchronous compensator) is a DC-excited synchronous machine (large rotating generators) whose shaft is not attached to any driving equipment.
How a synchronous motor can be used as a synchronous condenser?
Overexciting Fields of Synchronous Motors Such a device is known as a synchronous condenser. Furthermore, the leading power factor can be adjusted by varying the field excitation. This makes it possible to nearly cancel an arbitrary lagging power factor to unity by paralleling the lagging load with a synchronous motor.
What are the applications of synchronous motor?
Synchronous motors are normally used in applications in which a constant and precise speed is required. Typical applications of these low power motors are positioning machines. They are also used in robot actuators. Synchronous motors are also used in ball mills, watches, record players, and turntables.
What is meant by synchronous capacitor?
In electrical engineering, a synchronous condenser (sometimes called a synchronous capacitor or synchronous compensator) is a DC-excited synchronous motor, whose shaft is not connected to anything but spins freely. One advantage is the amount of reactive power from a synchronous condenser can be continuously adjusted.
What is the application of synchronous compensator?
Explanation: The main application of the synchronous compensators is to control the reactive powers. They are designed to speeds upto 3000 rpm.
What is the application of synchronous compensators?
What is the importance of synchronous condenser?
The advantages of a synchronous condenser are that we can control the power factor of system smoothly without stepping as per requirement. In case of a static capacitor bank, this fine adjustments of power factor cannot be possible rather a capacitor bank improves the power factor stepwise.
How is a synchronous motor used in a power system?
Owing to its characteristics to behave at any electrical power factor, it is used in power system in situations where static capacitors are expensive. Synchronous motor finds application where operating speed is less (around 500 rpm) and high power is required.
What happens to stator current in synchronous condenser?
As the mechanical load on a synchronous motor increases, the stator current Ia increases regardless of the field excitation. For both under and over excited motors, the power factor (p.f.) tends to approach unity with increase in mechanical load.
What happens if the motor falls out of synchronization?
Since the motor cannot produce (synchronous) torque if it falls out of synchronization, practical synchronous motors have a partial or complete squirrel-cage damper (amortisseur) winding to stabilize operation and facilitate starting.
Why are synchronous condensers used as alternative to capacitors?
The use of rotating synchronous condensers was common through the 1950s. They remain 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 useful for supporting voltage levels.