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When a load on a normally excited synchronous motor is increased its power factor tends to?
Wiki User
∙ 12y ago
power factor normally goes to the lagging
Wiki User
∙ 12y ago
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What is synchronus capacitor?
A synchronous condenser (also known as a synchronous capacitor or synchronous compensator) is a DC-excited synchronous computer (large rotating generators) whose shaft is now not connected to any using equipment.
What is runaway speed of synchronous machine?
A synchronous electric motor is an AC motor in which the rotation of the shaft is synchronized with the frequency of the ACsupply current; the rotation period is exactly equal to an integral number of AC cycles. Synchronous motors contain electromagnetson the stator of the motor that create a magnetic field which rotates in time with the oscillations of the line current. The rotor turns in step with this field, at the same rate.Another way of saying this is that the motor does not rely on "slip" under usual operating conditions, and as a result produces torque at synchronous speed. Synchronous motors can be contrasted with induction motors, which must slip in order to producetorque. The speed of the synchronous motor is determined by the number of magnetic poles and the line frequency.Synchronous motors are available in sub-fractional self-excited sizes to high-horsepower direct-current excited industrial sizes. In the fractional horsepower range, most synchronous motors are used where precise constant speed is required. In high-horsepower industrial sizes, the synchronous motor provides two important functions. First, it is a highly efficient means of converting AC energy to work. Second, it can operate at leading or unity power factor and thereby provide power-factor correction.
What is compounding curve in synchronous motor?
The operation of a synchronous generator delivering power to a constant power-factor load is demonstrated by means of compounding curves. A compounding curve shows the field excitation needed to maintain rated terminal voltage as the load is varied.
How you do Speed control of permanent magnet synchronous motor?
To vary the speed of a permanent magnet synchronous motor, you need to vary the frequency of the AC power source. Of course, this also means you need to vary the voltage because the power factor is going to change, and you need to compensate for that or you might damage the motor.
Causes of low power factor methods of improving power factor?
using highly inductive loads may lead to reduction in the power factor. or consumption of unappreciable amount of power also results in the same. methods to improve PF . using synchronous condensers using capacitor banks using ow inductive loads
When load on a normally excited synchronous motor is increased its power factor tends to what?
approach unit
What is synchronus capacitor?
A synchronous condenser (also known as a synchronous capacitor or synchronous compensator) is a DC-excited synchronous computer (large rotating generators) whose shaft is now not connected to any using equipment.
When you should use synchronous motor instead of capacitor for power factor correction?
Synchronous motors show some interesting properties, which finds applications in power factor correction. The synchronous motor can be run at lagging, unity or leading power factor. The control is with the field excitation, as described below:When the field excitation voltage is decreased, the motor runs in lagging power factor. The power factor by which the motor lags varies directly with the drop in excitation voltage. This condition is called under-excitation.When the field excitation voltage is made equal to the rated voltage, the motor runs at unity power factor.When the field excitation voltage is increased above the rated voltage, the motor runs at leading power factor. And the power factor by which the motor leads varies directly with the increase in field excitation voltage. This condition is called over-excitation.The most basic property of sycho motor is that it can be use as a CAPACITOR OR INDUCTOR both. Hence in turn it improves the power factor of system.The leading power factor operation of synchronous motor finds application in power factor correction. Normally, all the loads connected to the power supply grid run in lagging power factor, which increases reactive power consumption in the grid, thus contributing to additional losses. In such cases, a synchronous motor with no load is connected to the grid and is run over-excited, so that the leading power factor created by synchronous motor compensates the existing lagging power factor in the grid and the overall power factor is brought close to 1 (unity power factor). If unity power factor is maintained in a grid, reactive power losses diminish to zero, increasing the efficiency of the grid. This operation of synchronous motor in over-excited mode to correct the power factor is sometimes called as Synchronous_condenser.
How you improve power factor in synchronous motor?
Power Factor measures the difference in phase between the current and voltage. When they are in phase the Power Factor is defined as 1. When out of phase the value is less than 1. If they are 180 degrees out of phase the Power Factor will be zero.
What is the use of synchronous machines in power grid system?
To improve the power factor
What is runaway speed of synchronous machine?
A synchronous electric motor is an AC motor in which the rotation of the shaft is synchronized with the frequency of the ACsupply current; the rotation period is exactly equal to an integral number of AC cycles. Synchronous motors contain electromagnetson the stator of the motor that create a magnetic field which rotates in time with the oscillations of the line current. The rotor turns in step with this field, at the same rate.Another way of saying this is that the motor does not rely on "slip" under usual operating conditions, and as a result produces torque at synchronous speed. Synchronous motors can be contrasted with induction motors, which must slip in order to producetorque. The speed of the synchronous motor is determined by the number of magnetic poles and the line frequency.Synchronous motors are available in sub-fractional self-excited sizes to high-horsepower direct-current excited industrial sizes. In the fractional horsepower range, most synchronous motors are used where precise constant speed is required. In high-horsepower industrial sizes, the synchronous motor provides two important functions. First, it is a highly efficient means of converting AC energy to work. Second, it can operate at leading or unity power factor and thereby provide power-factor correction.
If the antenna diameter in radar system is increased by a factor of 4 then the maximum range will be increased by a factor of?
16
Observing a variable star whose total flux has increased by a factor of 625 By what factor did its temperature change?
increased by 5 is the answer!
How does the electric potential energy between two charged particles change if one particle's charge is increased by a factor of 2?
It is increased by a factor of 2
What is the difference between synchronous motor vs induction motor and which one is better?
The big difference is that the synchronous motor's rotor can have a variable current applied to it through its field slip rings. Both types of motors have their own advantages. With a synchronous motor in the system, the systems power factor can be regulated.
In a negative correlation as one factor is decreased the other factor?
In a negative correlation as one factor is decreased, the other factor is increased.
How can phase advancers improve the power factor?
PHASE ADVANCER:phase advancers are used to improve the power factor of induction motors.The low power factor of an induction motor is due to the fact that its stator winding draws exciting current which lags behind the supply voltage by 90 degree.If the exciting ampere turns can be provided from some other A.C. source,then the stator winding will be relieved of exciting current and the power factor of the motor can be improved.This job is accomplished by the phase advancer which is simply an A.C exciter.The phase advancer is mounted on the shaft as the main motor and is connected in the rotor circuit of the motor. It provides exciting ampere turns to the rotor circuit at slip frequency.By providing more ampere turns than required,the induction motor can be made to operate on leading power factor like an over-excited synchronous motor.
