Design of FPGA based controller for trapezoidal modulated cycloinverter

In this paper a digital controller has been designed and implemented on field programmable gate array (FPGA) to generate the trigger pulses for a trapezoidal modulated cycloinverter using hardware description language. Trigger requirements are obtained for single-phase centre tapped transformer configuration. With successively improving reliability and performance of digital controllers, the digital control techniques have predominated over other analog counter parts. There are many advantages of digital controllers such as reconfigurability, power saving options, less external passive components and less sensitive to temperature variation. Peripheral input-output and FPGA interfacing through Xilinx 9.2i has been developed to generate Trapezoidal pulse width modulation PWM trigger signal for the cycloinverter. The trigger circuit has been tested qualitatively by observing various triggering pulses on Tektronix digital storage oscilloscope (DSO). The operation of proposed system has been found satisfactory.