# What is the formula of alternator?

## What is the formula of alternator?

V = 4.44 Kf KC KD f ΦT Volts. V = Actual generated Voltage per phase. KC = Coil Span Factor or Pitch Factor.

How do you calculate EMF of an alternator?

EMF equation of alternator

1. By faraday’s law of electromagnetic induction, the emf induced is proportional to rate of change of flux.
2. RMS value of emf per phase = Form factor x Average value of induced emf = 1.11 x 4 Φ f T.

How do I calculate alternator excitation voltage?

Re: Alternator Excitation Voltage KVA at 5 MW = 1.732 * 11* 328 = 6249 KVA. excitation required at 5 MW = 6249*150/9373 = 100 V.

### What is the maximum speed of a 50hz alternator?

Speed of alternator is given byrpmFor 50 Hz frequency the maximum speed is 3000 rpm for two pole p=2.

Why alternators are rated in KVA?

Why Alternator rated in KVA or MVA? (1) Power Factor is depended on the type of load or power consumers, not on the power generators. As the alternator is not a load so there is no power factor concept comes. So the alternator is rated only based on current and voltage that is VA, KVA or MVA.

What is the formula for calculating emf?

The emf is equal to the work done on the charge per unit charge (ϵ=dWdq) when there is no current flowing. Since the unit for work is the joule and the unit for charge is the coulomb, the unit for emf is the volt (1V=1J/C).

## Why is alternator rated in KVA?

Why is DC used for excitation?

Why only D.C is used for Excitation in Alternators? Excitation voltage or current is supplied to the field windings of a rotor to produce a static magnetic field. If we use alternating current instead of direct current; we will get a fluctuating magnetic field.

When the speed of an alternator increases the frequency?

As speed of an alternator is in direct proportion with the frequency. As speed increase frequency is also get increase.

### What will be the frequency per revolution in an alternator?

For example, if the armature is spinning at a rate of 1800 RPM on a two-pole alternator, we can say that it is spinning at 30 rotations per second. If this alternator has two poles, then in one second it will generate 30 cycles of voltage. It then could be said to have a frequency of 30 cycles per second or 30 Hertz.

How do you size an alternator?

As a rule of thumb, 12-volt alternators use one horsepower for every 25 amps of output, or to put it another way, their ratio of output to horsepower load is 25:1. So, when selecting a new alternator, you need to size it for the limits of the capacity of its drive belt.