FOUR QUADRANT OPERAT ION OF DUAL CONVERTE R BASED DC DRIVE S

With recent advances in Power Electronics , electric variable - speed Drives are witnessing a revolution in various application s . Power electronic devices are becoming able to easily tailer the rigid characteristics of the motor (when driven from a fixed DC or AC supply source) to the requirements of load. Because of inherent ease of speed control of the separately excited DC m achine, DC drives are used in rolling mills, paper mills, mine winders, hoists, machine tools, traction, printing presses, textile mills, excavators and c ranes etc., where speed control is done by varying the applied armature voltage. This variable armature voltage is simply generated by Phase - Controlled Rectification which has now almost entirely replace d the Ward - Leonard systems prev iously used. Half Converter, Semi Converter, Full Converter and Dual Converter are some of the Thyrister controlled Rectifier circuits. This paper presents matlab simulation model of D ual converter (single phase) circuit. Simulated results show that th i s converter of fer variable DC voltage which is capable of four - quadrant operation of the drive in speed - torque plane . We can thus have bi - directional load current and dc output voltage.