FPGA based adaptive delta modulated direct matrix converter

Abstract

This paper proposes a single phase direct matrix converter employing Insulated-gate bipolar transistors. The output frequency of the converter has been varied over a wide range. The Adaptive Delta Modulation (ADM) technique is used here, in order to minimize the harmonics. The proposed converter not only works as a Cyclo-inverter (CI) but also as a Cyclo-converter (CC). The performance analysis is done using output voltage and associated total harmonic distortion (THD) waveforms on MATLAB/Simulink platform for different mode of operations. Simulated results for CI, show that the minimum THD is approximately 3.3 % at output frequency, f0 = 1 kHz whereas it is less than 1 % at f0 = 100 Hz. For CC, the observed THD values are 0.93, 0.92 % at f0 = 25 and 5 Hz respectively. The experimental set-up for the converter circuit has also been developed using VHDL and FPGA kit, in order to verify the simulated results. The experimental results are in the close vicinity and conformity to the simulated observations.