EMC characteristics of lighting systems

[Truncated abstract] This thesis examines Electromagnetic Compatibility (EMC) characteristics of lighting systems. The issues examined have become more significant with the rapid development of both lighting systems and general electronics devices such as Blue Tooth and RFID tags. Every commercial and industrial building has lighting systems consisting of wiring, electronic ballasts, dimmers, luminaires and the like. Except for the occasional need to change a lamp, typically each lighting system remains unaltered during the life of the building which can be several decades. Computers and related electronic products which are operated within such buildings are continually being updated or replaced as they become obsolete and new products become available. Computer systems are expected to perform flawlessly at all times and yet Electro Magnetic Interference (EMI) emanating from lighting systems can cause such systems to experience disruption. Such disruption causes delay and cost to commercial enterprise. A luminaire must necessarily be located very close to a work area. Data transmission can be adversely affected by coupling of radiated electromagnetic field from a luminaire. Even if there are no radiation emissions, conducted emissions are almost always present, transmitted via power lines and thereby exposing nearby computers to the risk of disruption. Where EMI causes disruption, it may become necessary to modify the entire lighting system in the work area or building. Often such remedial work will incur substantial costs by way of labour and replacement parts, as well as the business costs associated with computer down time in the work environment. The concepts and results presented in this thesis will provide a means to reduce the impact of certain EMI from lighting systems in computer work environments by ensuring that luminaires are properly characterized to screen out those which exhibit unpredictable behaviour.