- Consider that an instantaneous voltage v be represented by the formula
v = Vm sin 2πft volts.
This is a waveform which varies sinusoidally with time t, has a frequency f, and a maximum value represented by Vm. It is normally assumed that alternating voltages have wave shapes which are sinusoidal where only 1 frequency is present. If the waveform is not happened to be sinusoidal it is called a complex wave, & whatever its shape is, itmay be split up mathematically into components called the fundamental and a number of harmonics.This process is referred to as harmonic analysis.The fundamental, which is the first harmonic, is sinusoidal and has the supply frequency, f ; the other harmonics are also sine waves having frequencies which are integer multiples of f . Thus, if supply frequency is fifty hertz, then the third harmonic frequency is 150Hz, the fifth 250Hz, & so on.
