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Why a rotor of an alternator at rated power dissipates more heat at a low power factor load than at a high power factor load?
Wiki User
∙ 12y ago
at lower power factor current drawn by load is high and at higher pf the current drawn is less...
Wiki User
∙ 12y ago
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Why generators are rated at 0.8 lagging power factor?
Rated power factor
How many KVA of genset to produce 10000watts?
A gen set will be rated for a certain kVA at a certain power factor, or certain kW at a certain power factor. If rated in kVA, the power factor indicates the amount of real power you will get (ie if rated at 10,000kVA at .95 pf, the gen set can generate .95 x 10,000kW, or 9,500kW).
What is VA rating?
VA Rating stands for Volt-Ampere Rating, It is the basic unit of Alternator or Transformer. This is so because in AC System Power(P) is the product of Voltage(V),Current(I)and Power Factor. Power(P) = Voltage(V) * Current(C) * Power Factor But power factor of the load is never constant and depends on the type of load. So to resolve this problem power ratings of the above mentioned machine is always rated in VA or KVA and its the product of voltage and current.
Why unity power factor is used in load test?
When power factor is at unity, the voltage and current waves are aligned or in phase with one another. Since power is the product of voltage and current, power transfer is maximized at unity power factor. When power is transmitted at a lower power factor, greater current is required to deliver the same amount of power. When current is increased, the size of the transmission, distribution and generation systems, all have to be increased accordingly, along with the price of the killowatt-hour at the meter.
Why does a transformer rated in KVA or VA?
Because the manufacturer has no way of knowing the power factor of load it will be supplying. So its rating is always the product of its rated voltage and its rated current, which is in volt amperes.
Why the rotor of an alternator at rated power dissipates more heat at a low power factor load?
In an alternator, the load current is supplied by the stator and the excitation is applied to the rotor. When the power factor is low (lagging), more excitation is required to maintain rated output voltage at rated current. More excitation is also required to maintain rated output voltage with increased output current. Increased excitation current means increased rotor losses that must be dissipated as heat. (akash)
Can we improve generator power factor for increasing active power?
The 0.8 Power Factor provided by generator manufacturers is not the load power factor, but it is the nominal power factor used to calculate the kW output of an engine to supply the power for a particular alternator kVA output. Alternators are therefore designed to supply their rated kVA at 0.8 lagging power factor.
Why generators are rated at 0.8 lagging power factor?
Rated power factor
Why does the rotor of an alternator at rated power dissipates more heat at a low power factor load than at a high power factor load?
Equation for power in an AC circuit is Power (P) = root3 Voltage (V) x Current (I) x power factor (cos phi) P = root3 V I Cos Phi. Value of cos phi is maximum 1. Normally 0.95 and above is considered to be good. root 3 and V assuming to be constant, if the cos phi is low, to be able to supply rated power, the system draws increased current (I). With increased current IR and copper losses increase resulting over heating of the motor.
What is alternator output in amps?
The alternator (or generator) of a vehicle is the unit that converts the mechanical energy from the drive-belt into electricity. Amperage (amps) are the output level of the alternator. Alternator part number, as well as output amps are specific to each vehicle.Another AnswerYour question is a little like asking, "How long is a length of string?"! The rated output current of an alternator depends on its rated output power rating and its rated terminal voltage. The rated output power can vary tremendously, according to the physical size of the machine.
How many KVA of genset to produce 10000watts?
A gen set will be rated for a certain kVA at a certain power factor, or certain kW at a certain power factor. If rated in kVA, the power factor indicates the amount of real power you will get (ie if rated at 10,000kVA at .95 pf, the gen set can generate .95 x 10,000kW, or 9,500kW).
Why ups rated in kva?
The kva rating includes the power factor of the connected load.KW * Power Factor = kva.AnswerThe above answer is incorrect, as it's actually kV.A x power factor = kW.The answer is straightforward, the output of the UPS is the product of its rated output voltage and its rated output current, and the product of voltage and current is 'apparent power', expressed in volt amperes.
What is VA rating?
VA Rating stands for Volt-Ampere Rating, It is the basic unit of Alternator or Transformer. This is so because in AC System Power(P) is the product of Voltage(V),Current(I)and Power Factor. Power(P) = Voltage(V) * Current(C) * Power Factor But power factor of the load is never constant and depends on the type of load. So to resolve this problem power ratings of the above mentioned machine is always rated in VA or KVA and its the product of voltage and current.
Why transfuarmer rated in kva?
why not ? a 1000kva means you will get the power out as 1000kv per amp in essence it can be a 100v with 10 amp out. means the same thing to me. It's power factor depends upon the load. Thus we can not give absolute value of KW rating of a Xmer or an alternator in the manufacturing plant.
What equipment used in power factor improvement?
The simplest method of power-factor improvement is by using appropriate capacitors, connected in parallel with the load. Power-factor improvement capacitors are rated in reactive volt amperes, not farads.
Why Voltage x Current do not equal rated power?
In an AC system power is equal to Voltage x Current x Power factor. Power factor is not constant and depends on the type of the load. Ideal value of the Power factor is 1, where as practically remains less then 1.
How do you calculate capacitor rating for improving power factor?
Power-factor capacitors are rated in reactive volt amperes. To determine the appropriate rating, it is necessary to determine the existing (inductive) reactive power of the load, then determine the amount of (capacitive) reactive power necessary to achieve the desired power factor (it's rarely economical to try and achieve unity power factor), and this will be the necessary reactive power of the capacitor bank.The capacitance of power-factor correction capacitors is not really relevant to the calculation, which is why they are rated in reactive volt amperes, rather than in farads.
