Implementation of FPGA based DPWM-Digital PI Closed Loop Controller for Voltage Regulation

Abstract

Objectives: In this paper, a Field Programmable Gate Array (FPGA) based real time implementation of a closed loop controller for regulating the load voltage under line and load disturbances by generating Digital Pulse Width Modulation (DPWM) is developed. Digital Proportional Integral (DPI) controller is designed to generate the DPWM. Methods: DPWM are developed by two methods: Counter based and Delay line based. The closed loop DPWM activated DC-DC buck converter is simulated using MODELSIM and tested in real time using Xilinx Spartan 3A DSP FPGA. Findings: Hardware results show the regulated load voltage by updating the DPWM control signal duty cycle to compensate the line and load disturbances. FPGA based DPWM provides less complexity in design. Improvements: Hybrid based DPWM method with closed loop control for DC-DC Buck converter could be used for voltage regulation.