Design Of Variable Frequency Power Supply System Based On DSP

Variable frequency power is a device which converts civil AC power through power conversion circuit into AC power sine wave with required frequency and voltage. The output frequency and voltage are adjustable within a certain range. This paper presents a single-phase variable frequency power design based on digital signal processor (DSP), and tested the system for exporting sine wave power with adjustable voltage and frequency.The input of the variable frequency power supply is 220V/50Hz single-phase AC power, the output is AC power sine wave with adjustable voltage and frequency. The frequency range is 20-400Hz.This paper introduces the fundamental theory and structure of the digital variable frequency power supply, and discusses the principle of SPWM modulation techniques and features of different modulation methods. It also discusses the causes, impacts and compensation measures of dead time effect. This paper introduces the principle and implementation of digital PID control and fuzzy PID control. The paper presents the hardware design, including power circuit, control circuit and man-machine interface; and software design including DSP software and MCU software. The paper designs a certain number of tests for the variable power supply, and shows waveforms of the circuits and the close-loop output waveforms. The results of output voltage test and output frequency output are used to study on features of the power supply system. At the end, the paper discusses the drawbacks of the power supply system and prospects for the following research.