The Intelligent And Green Urban Illumination Regulating System

As resource depletion and the carbon emissions, Energy-saving and environmental protection has become a world-wild trend in the modern society. The electricity which consumed by illumination takes a great percentage in the generating capacity every year. The common energy saving lamps usually works less efficient under 220 volts. The intelligent urban illumination regulating system transforms the AC 220 volts into the energy-saving voltage to save the energy, and reduces the harmonic components.This thesis introduce the fundamental principle and system components of the intelligent urban illumination regulating system. The voltage-frequency changing discipline of the grid and the working principle of the lamp were analyzed in this paper. The AC chopper circuit and the control sequence in time were researched. The system uses CPLD as the mainly controlling device which working with the IGBT chopper regulator. The Hall devices is used to detect the voltage and current. The circuit structure is referred the typical AC chopper topology. By researching the different voltage-current phase character of different load, a zero-crossing detection method was designed to protect the main circuit from short circuits which cause by zero-crossing oscillation. By researching the controlling timing sequence of the AC chopping, a zero-crossing based non-complementary. By researching the load feature, a gradually changing PWM controlling method was designed to achieve the voltage soft-transition. By analyzing the harmonic components of the AC chopping outlet circuit, the LC filter network was designed.To test the performance of the system, it is used to supply different types of loads. The continuous experiment shows that the intelligent urban illumination regulating system can run stably on different load conditions. By test the inner controlling signal of the zero-crossing circuit, the AC zero-crossing short circuit can be avoided. The system achieved the voltage soft-transition, and avoided the phenomenon of voltage overshoot and over current. The AC voltage supplied by the system contains no voltage distortion and only a small quantity of harmonic component.