Research And Design Of A Variable Voltage AC Power Supply With Numerical Control

Electric energy is one of the most important energy for the human production and life. Reasonable, efficient, accurate and easy to use electric energy is still a major problem. Stability, reliability, accuracy and efficiency are important for power supply, but small size and light weight are also very pressing needs. At present, high frequency, small components and structures is the primary mean to solve the problem. Power electronics technology in the power supply brings a revolution in the use of electric energy.The technique of phase-control AC voltage regulator has a faster response time, which is less than a cycle voltage power. But the output voltage and current contains a lot of harmonic, so it requires a larger capacity filter and has low power factor. The technique of AC voltage regulator with chop-control is a new and high-performance technology. Based on analysis of harmonic output voltage of chopping AC voltage regulator and automatic control theory, the paper designed an AC voltage regulator scheme.This paper elaborated the theory of AC voltage regulator with chop-control at first, which was mainly about harmonic analysis. After that, the paper designed the main circuit, including the parameters of the output filter circuit and IGBT buffer circuit. In order to achieve non-complementary control, the paper designed zero-voltage and current detection circuits. STC12C5410AD MCU as a core control devices. The loop of AC voltage regulator controlled by improved digital PID.Chopping AC voltage regulator is easy to filter and the output voltage has fewer harmonics from experiment. Compared to phase-control AC voltage regulator, chopping AC voltage regulator has more advantages.