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What affect does a leading power factor have on alternator generator excitation currents?
Thefuzz1301
When a leading power factor load is applied, the voltage of the genset or genset bus rises, and the voltage regulation system reduces exciter power, reducing the strength of the magnetic field. If the field fails, the generator set may slip a pole, which results in potentially catastrophic alternator damage. pawan
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∙ 16y ago
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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 reverse power will occur during synchronizing?
Reverse power flow into a generator can occur during synchronization if the generator is spinning too slowly, or the voltage phase angle is lagging relative to the power system. If the generator is spinning too slowly, power from the system is used by the generator to increase its' speed. If the phase angle is lagging, an initial spike of power will flow into the generator to force it into sync with the system. Typically generator's will match system frequency very closesly, and force the phase angle to leading slightly between the generator and the system. When synchronized, an extra bump of power will flow out while the generator is torqued into phase with the system. This will avoid tripping any reverse power devices.
What is the function of capacitor in an electric generator?
In an electric generator, the function of a capacitor is to provide reactive power and improve the power factor of the generator. When a generator is connected to a load, the load may have a combination of resistive, inductive, and capacitive components. Inductive loads can cause the power factor of the generator to decrease, resulting in lower efficiency and voltage regulation. By adding a capacitor in parallel with the generator, the reactive power generated by the capacitor can offset the reactive power of the inductive load, leading to improved power factor correction. This helps to enhance the efficiency of power transfer and stabilizes the voltage. The capacitor absorbs and supplies reactive power, reducing the strain on the generator and ensuring a steady and efficient supply of electrical energy.
What lagging or leading?
You must knew there's a sinusoidal wave form for both voltage nd current. That wave form is drawn between voltage/current nd phase angle. Unity: phase angle of voltage nd current matches, irrespective of magnitude leading: phase angle of current leads voltage by an angle lagging: phase angle of voltage leads current or current lags voltage by an angleAnswerThe terms, 'leading' and 'lagging' apply to a.c. loads. 'Leading' means that the load current leads the supply voltage, whereas 'lagging' means that the load current lags the supply voltage. 'Leading' currents occur in capacitive loads, whereas 'lagging' currents occur in inductive loads.'Leading' and 'lagging' refers to what the current is doing, relative to the voltage, never the other way around.
How does turbine work?
Steam or water, it works the reverse of a fan, where the fan pushes air down, the turbine is turned by the steam or water. there's a shaft leading from the turbine to the generator, which produces the electricity
What are the disadvantages of leading power factor on generator supply system?
in case of leading power factor the air gap flux inside the alternator will increase which may cause over heating of the stator end coil and overhang portions.
Can cipro affect tinnitus?
Yes. This is mediated by ciprofloxacin's antagonism of the GABA(a) receptor, leading to NMDA receptor over-excitation and tinnitus.
What happens if the synchronous motor exceeds its load capacity?
If load on a generator is greater than the generator can provide, the generator will begin to slow down. If it slows down too much, it will lose synchronism.
Why does an alternators voltage rise when it is loaded down with a leading load?
Because in the leading load or capacitive load the armature reaction is magnetizing.Here the stator flux adds up rotor flux and so the net flux of alternator increases and the net flux produces alternator's voltage.Hence the alternator's voltage rises.
Can a motor act like an electric generator?
when the motor runs more than rated speed it produces leading current and results act as a generator. (or) the motor act as generator when it produces more back e.m.f
An alternator could be severely damaged mechanically in attempting to sychronize it with the power line under what two conditions could this happen?
I'm not sure this qualifies as two different conditions, they are both similar.If the generator is more than a few degrees out of phase.If the generator phase angle is leading at the exact moment it closes to the bus.Explanation for #2: When manually syncing a generator, it is quite difficult to close the breaker at exactly 0 degrees, which is, of course, the desired outcome. If you close the breaker with the generator lagging a few degrees, the bus voltage (utility or other generator) will attempt to speed up the generator as if it were starting a motor.No harm done if the phase difference is just a few degrees. If, on the other hand, you close the breaker while the generator is leading, the bus voltage attempts to 'yank' the generator back to where it belongs, like a brake. If the phase difference is great enough, this can shear driveplates and even break crankshafts!The operator, then, shoots for zero to a couple degrees lagging when the breaker closes.
What is a quality portable home generator?
One of the leading brands is Colemans when it comes to generators. We have been trusting Coleman's to meet our outdoor needs for years and they are the only generator you should trust.
What is the leading contributor to the extinction rates of terrestrial and freshwater organisms?
currents, turbulence of fast-moving rivers and streams. :)
Why is it important that a pendulum in a clock is heavy?
If the pendulum is light it will be susceptible to perturbations from air currents, leading to a loss of accuracy.
Would you compare generator current to line voltage to determine if your leading or lagging?
It's always the current that determines 'leading' or 'lagging' -i.e. the angle by which the current leads or lags the voltage.
You had the alternator replaced now having electrical problems?
Electrical "Problems" Following Replacement of AlternatorUsually this is an indication that the electrical wiring system is "screwed up."Either there was an existing problem, leading to the need to replace the alternator, OR whoever changed the alternator screwed up the wiring.
When synchronus generator is supplying active and reactive power it is operating at leading or lagging power factor?
A synchronous generator is operating at lagging power factor (positive P & Q) when it is supplying P & Q to the system. P & Q are positive which means that they are flowing away from the bus where the generator is connected (overexcited case). On the other hand, it is operating at leading power factor when it is supplying P and absorbing Q. The sign of Q is negative which means that it is flowing towards the generator bus (underexcited case).
