FPGA-based variable modulation-indexed-SPWM generator architecture for constant-output-voltage inverter applications

摘要

Modulation Index (MI) variant sinusoidal-pulse-width-modulation (SPWM) is desirable for converter applications in maintaining output voltage under variable input and load environments. Enabling a highspeed switching and resolution, field-programmable gate-arrays (FPGAs) have been dominating in digital control of power electronics. This paper proposes an FPGA-based high-frequency high-resolution digital variable-modulation-indexed sinusoidal-pulse-width-modulation (DVMI-SPWM) generator architecture which can support the requirements of modern high-frequency switching and the MI adjustment ability in voltage-source-inverter (VSI) applications. A mathematically formulated optimized finite-state-machine (FSM) architecture is introduced, which adopts MI of SPWM by adjusting the duty-cycle values of SPWM pulses based on the measured feedback signal. The design employs a minor segment of medium-sized FPGA and, thereby, provides a good trade-off for multi-functional and larger schemes. The post-design simulation and experimental results validate that compared to the earlier-reported architectures, the proposed DVMI-SPWM architecture is the most appropriate one for variable MI applications with improved performance such as lower power consumption, lower harmonic distortion, and higher resolution. (c) 2020 Elsevier B.V. All rights reserved.