Energy efficiency of distribution transformers

Abstract-Losses in distribution transformer

Sources de la lumière artificielle durant les ères romaine, byzantine et post-byzantine : une évaluation de leurs performance

The assessment of the performance of ancient lighting devices may provide scholars with valuable information on the lighting conditions that existed in ancient houses, and on the level of optical comfort created by the use of those devices. Consequently, it also provides scholars with valuable information on the feasibility of activities performed during night time. This paper focuses on the investigation of the performance of lighting devices, namely lamps and candles, used in Greece during the Roman, Byzantine, and Post-Byzantine eras. At the same time, we provide non-lighting specialists (e.g. archaeologists) with the tool to assess the performance of the lighting devices they study, as well as to estimate the amount of light emitted on a surface of interest

Embedded Microcontroller with a CCD Camera as a Digital Lighting Control System

Although with the advent of the LEDs the energy consumption in buildings can be reduced by 50%, there exists a potential for energy savings due to lighting controls. Moreover, lighting controls can ensure that the near zero energy requirements by EU can be achieved for near zero energy buildings (nZEBs). For this reason, more sophisticated lighting controls must be proposed in order to take full advantage of LEDs and their flexibility concerning dimming. This paper proposes the architecture of an embedded computer camera controller for monitoring and management of image data, which is applied in various control cases, and particularly in digitally controlled lighting devices. The proposed system deals with real-time monitoring and management of a GigE camera input. An in-house developed algorithm using MATLAB enables the identification of areas in luminance values. The embedded microcontroller is part of a complete lighting control system with an imaging sensor in order to measure and control the illumination of several working areas of a room. The power consumption of the proposed lighting system was measured and was compared with the power consumption of a typical photosensor. The functional performance and operation of the proposed camera control system architecture was evaluated based upon a BeagleBone Black microcontroller board