Low cost FPGA implementation of SPWM using dynamically configurable switching frequency for three phase voltage source inverter

This paper describes the design, implementation and analysis of FPGA based High Frequency Switching Sinusoidal Pulse Width Modulation (SPWM) generator for the application of three-phase DC/AC inverters using Pipelined CORDIC algorithm. The carrier frequency of up to 4 MHz and operating frequency of 256 MHz is achieved. The switching frequency can be dynamically reconfigurable on real time by the user/external input signal ranging from 312.5 KHz to 256 MHz, which has wide application in the area of DC/AC inverters, thus allowing the flexibility to adapt for different power switching devices which has different non-linear characteristics. The work also includes the analysis of Total Harmonic Distortion (THD) using MATLAB, which shows the reduction in harmonic content. The entire architecture has been implemented by using the smallest FPGA XC6SLX4-TQG144 available in Xilinx Spartan 6 family. The proposed architecture exhibits highest switching frequency, lower power consumption, lower area and generating the stable SPWM waveform by using a low cost FPGA available in the market.