Question

What Is the formula for the amplitude of the fundamental curve?

(a) amplitude of the fundamental curve = 1.27 * flux density in the air gap * cosine (phase angle/2)

(b) amplitude of the fundamental curve = 1.27 / flux density in the air gap * cosine (phase angle/2)

(c) amplitude of the fundamental curve = 1.27 * flux density in the air gap / cosine (phase angle/2)

(d) amplitude of the fundamental curve = 1/1.27 * flux density in the air gap * cosine (phase angle/2)

I have been asked this question in class test.

This intriguing question originated from Field Form, Harmonic Analysis of Flux Distribution Curve in chapter Principles of Magnetic Circuit Design of Design of Electrical Machines

Answer 1

Correct choice is (a) amplitude of the fundamental curve = 1.27 * flux density in the air gap * cosine (phase angle/2)

To explain: The flux density in the air gap is calculated along with the cosine of the phase angle divided by 2. On substitution, the amplitude of the fundamental curve is calculated.