20 May 2017

Principle of Inverter

  • The basic circuit for voltage driven inverter is shown in the figure A. 
  • The DC supply is given to the primary winding of the transformer.
  • There are two semiconductor switches S1 and S2 in which switching is done by astable multivibrator at selected frequency. 
  • When the switch S1 is kept on, the current flows through transformer upper primary winding resulting the flux generates in the core and induced emf in it.

voltage-source-inverter.png

  • Similarly when switch S2 is kept on, the current flows through lower part of the transformer primary winding resulting the flux generates in the reverse direction.
  •  This will result in emf induced in the reverse direction. The switching of switch S1 and S2 are done alternately.
  • There is a transistor, SCR, MOSFET, IGBT or GTO used as a semiconductor device. 
  • The saturation voltage drop of these devices is low therefore it is neglected. As the input voltage is DC, the output is square wave.