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.