Implementation of digital communication modulation techniques in DC-DC converters for the suppression of EMI and enchancement of grid power quality [articol]

Abstract

In the vital requirement of power quality and suppression of EMI in SMPS, two types of digital modulation techniques are proposed in dc-dc converter. The two directsequence modulation techniques namely Binary-Phase Shift keying modulation and Quadrature-Phase Shift Keying modulation are implemented for the first time in dc-dc converter to enhance the grid power quality. The proposed modulation techniques are executed through a Field Programmable Gate Array by writing a VHDL coding for each modulation technique. The coding written is verified by Model Sim tool through ISE Xilinx software to produce gate pulse for the switch in dc-dc converter. Instead of building modulator physically, the modulation logic is implemented through VHDL coding, thus reduces the cost and space. On utilising this proposed DSSS modulation techniques, the EMI is reduced by 12 dBm and 24 dBm by BPSK and QPSK modulation respectively, when compared with traditional PWM technique.