FPGA Based SPWM Generation Technique for Single Phase DC/AC Converters

Power electronics is the technology associated with efficient conversion, control and conditioning of electric power from its available input in to the desired electrical output form. It has found on important place in modern technology being a core of power and energy control. The SPWM or sinusoidal pulse width modulation is widely used in power electronics to digitize the power so that a sequence of voltage pulses can be generated by the on and off of the power switches. The SPWM principle is widely used in dc/ac converters in energy conversion and motor drive applications. In this thesis, an FPGA-based SWPM generator is presented, which is capable to operate at switching frequencies up to 1 MHz (requiring FPGA operation at 100-160MHz), thus it is capable to support the high switching frequency requirements of modern power electronic DC/AC converters. The proposed design exhibits architectural flexibility features, enabling the change of the SPWM switching frequency and modulation index either internally, or externally. The proposed SPWM unit has been implemented in a single chip in order to enable the reduction of the DC/AC converter control unit complexity, cost and development time. Thus, the main contribution of this work is a system which is more faster in switching frequency than previously proposed ones and it has a more flexible architecture. Additionally, compared to the past-proposed designs, the proposed SPWM generation system exhibits less deviation of the generated SPWM output voltage from its theoretical value and consumes less power during operation. The VHDL language is used for coding and simulation is done using Xilinx ISE Design Suite 13.2.