3 phase power and 3 phase power generator

 3 phase power and 3 phase power generator

3 phase power generator

 3 phase power generator is a machine which generates 3 phase ac power. AC power is of two types. One is single phase and the other is multi phase. 3 phase is example of multi phase power which is very commonly used due to its special characteristics and powerful nature over single phase ac power. 3 phase power is generated in the same way as single phase power is generated. Only difference is the construction of 3 phase ac power generator. There are three seperate windings 120 degree apart each other. In a 3 phase power generator 3 windings are places 120° apart to make a complete machine having 3 separate windings in total of 360°. 

RMS value of a sin wave signal

Sin wave graphical presentation

A vector V is rotated in a circle completing 360 degrees. In this way the vector is passing through a sin wave as shown in the figure above. At the moment the vector is passing through 45 Degrees. At angle 90 degrees the vector passes through its maximum value. and at 180 degrees & 360 degrees the vector passes through its minimum value.

3 phase power generation

3 phase power generation

In the figure above, the generated emf or voltage is at maximum on the brown phase. The voltage of emf is increasing on the black phase. Whereas voltage or emf is decreasing on the gray phase. As you can see there are three sin waveforms each 120° apart. If all 3 phase power is added together, the vector sum would be zero. This is what is the 3 phase.