In the application of dc power control, chopper is widely used. Moreover it has been proved that in the field of traction thyristor-controlled chopper is superior to other schemes.
In general thyristor-chopper is categorized into soft commutation type and hard commutation type according to forced commutating methods.
This thesis includes the analysis of the two types mentioned above. Design consideration and Procedure of each type has been given on the comparative study point of view.
In order to enhance the efficiency and reliability of the device and the whole system, improved chopper scheme with saturable reactor has been proposed.
Experimental results include the waveforms of the various transient voltage and current of device & load.
