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.
