AN INTEGRATE APPROACH TO DESIGNING HIGH INTENSITY DISCHARGE LIGHTING SYSTEMS

  Highly efficient light sources are sought to help governments reduce the power consumption of lighting systems  (~15% of the total electric power generated is consumed by lighting) and hence the emissions of greenhouse gases in line with the Kyoto agreements. Outdoor lighting, especially roadways, is one of the most important areas particularly for safety and power consumption. The recent emergence of Metal Halide discharge lamps with Ceramic arctubes has led to a new generation of highly efficient light sources with high colour rendering indices which result in an improved perception. Further lamp optimisation, coupled with optimisation of the ballast characteristics, especially the possibility to dim the lamp remote with a minimum of adverse effect on the light colour. These together with optimisation of the optical properties of the fixture and, together with potential gains from sources specifically designed for human visual perception under mesopic lighting conditions have has the potential to dramatically reduce energy usage in roadway lighting by up to a factor of 2. Such systems would simultaneously improve the visual quality (i.e. improve road safety), energy efficiency and effectiveness of lighting schemes. We propose to develop an energy efficient and optimised outdoor discharge lighting system for urban illumination. A set of interacting engineering design tools will be generated to facilitate total system design, to include arctube, outer jacket lamp, ballast, remote control and fixture. A novel dimming ballast with a digital control interface and the respective control system will be designed. A prototype lighting scheme will be installed in a city to demonstrate the effectiveness of this approach.