FOUR QUADRANT OPERATION OF DUAL CONVERTER BASED DC DRIVES

With recent advances in Power Electronics, electric variable-speed Drives are witnessing a revolution in various applications. 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 machine, DC drives are used in rolling mills, paper mills, mine winders, hoists, machine tools, traction, printing presses, textile mills, excavators and cranes 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 replaced the Ward-Leonard systems previously 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  Dual converter (single phase) circuit. Simulated results show that this converter offer 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.