Current  Source Inverter (CSI)

Current  source  inverter has constant  input  but it  can be  adjusted. In CSI  the amplitude of output  current is  independent of load. The load voltage change  as per the magnitude of load impedance. When  a voltage  source  has a large  inductance in series with it behaves as a current source. The large inductance maintains the  constant. To  get ripple free current to CSI a large inductor L is  used before  CSI. A controlled rectifier bridge is used to obtained the de input  to CSI the CSI  converts this de current to an  ac current at its output terminal for this purpose four  thyristors are used with  inductive load. A capacitor C is  also connected across the  load to commutate the  thyristors and to improve the   power factor of the  circuit.