Energy saving controller for fluorescent lamps

Although fluorescent lamp is a very efficient lighting device in daily life, still the high harmonic distortion and low power factor cause unnecessary energy consumption. In today’s environment demanding energy efficiency, it is important to reduce this energy loss by integrating an energy saving controller in the electromagnetic ballast of fluorescent lamps. The research presented in this thesis investigates the design and implementation of a new energy saving controller for electromagnetic fluorescent lamp network. The newly developed controller attempts to reduce power losses in both the electromagnetic ballasts and fluorescent lamps by regulating the incoming supply voltage to an optimum level. In addition, the new controller is able to adjust the illuminance level of working environment lightings under either dark or bright condition. Moreover, the function of the new controller is extended with time scheduling control capability, where the switching of lighting systems can be controlled at predetermined times based on occupancy schedule. Both simulation and practical results show that the implemented controller reduces energy consumption by at least 37.5%, by reducing the incoming supply voltage by 15%. In addition, it is desirable to have variable illuminance level control to decrease the energy losses. The experimental results show that the illuminance output level of electromagnetic ballast fluorescent lamps can be decreased by 50% using the new controller while maintaining unity power factor. Integration of the new energy saving controller into electromagnetic ballast fluorescent lamps impressively outperforms the existing electronic dimmable ballast. This new controller brings great ideas for energy saving in the use of fluorescent lamps

Compact Fluorescent Plug-In Ballast-in-a-Socket

The primary goal of this program was to develop a ballast system for plug-in CFLs (compact fluorescent lamps) that will directly replace standard metal shell, medium base incandescent lampholders (such as Levition No. 6098) for use with portable lamp fixtures, such as floor, table and desk lamps. A secondary goal was to identify a plug-in CFL that is optimized for use with this ballast. This Plug-in CFL Ballastin-a-Socket system will allow fixture manufacturers to easily manufacture CFL-based high-efficacy portable fixtures that provide residential and commercial consumers with attractive, cost-effective, and energy-efficient fixtures for use wherever portable incandescent fixtures are used today. The advantages of this proposed system over existing CFL solutions are that the fixtures can only be used with high-efficacy CFLs, and they will be more attractive and will have lower life-cycle costs than screw-in or adapter-based CFL retrofit solutions. These features should greatly increase the penetration of CFL's into the North American market. Our work has shown that using integrated circuits it is quite feasible to produce a lamp-fixture ballast of a size comparable to the current Edison-screw 3-way incandescent fixtures. As for price points for BIAS-based fixtures, end-users polled by the Lighting Research Institute at RPI indicated that they would pay as much as an additional $10 for a lamp containing such a ballast. The ballast has been optimized to run with a 26 W amalgam triple biax lamp in the base-down position, yet can accept non-amalgam versions of the lamp. With a few part alterations, the ballast can be produced to support 32 W lamps as well. The ballast uses GE's existing L-Comp[1] power topology in the circuit so that the integrated circuit design would be a design that could possibly be used by other CFL and EFL products with minor modifications. This gives added value by reducing cost and size of not only the BIAS, but also possibly other integral CFL and future dimmable integral and plug-in versions of the EFL products

Energy Efficiency and Sustainable Lighting

The lighting of both exteriors and interiors is a field within electrical and lighting engineering, where important technological changes have been taking place oriented towards environmental sustainability and energy efficiency. LED technology has been gradually gaining ground in the world of lighting over other technologies due to its high lighting and energy efficiency and savings. However, some problems related to overheating or associated regulation are emerging. This has prompted the search for new, more efficient, and sustainable forms of lighting. This book presents successful cases related to energy efficiency and lighting that may be of great interest to those trying to enter the world of scientific research

Self-oscillating resonant converters: general approach and applications

En aquesta tesi es presenta el funcionament auto-oscil·lant de convertidors ressonants, produït per l'ús apropiat del signe del corrent de l'inductor d'entrada com a mecanisme de canvi de la polaritat de la tensió d'entrada. D'aquesta forma, el corrent d'entrada i el primer harmònic de la tensió d'entrada estan en fase, el que assegura un factor de potència unitari en estat estacionari. Aquest fet confereix una naturalesa de resistor lliure de pèrdues a la descripció del convertidor com biport. Es comprova que aquest mecanisme de generació de l'auto-oscil·lació és efectiu en estructures de segon, tercer i quart ordre. Encara que la creació de l'auto-oscil·lació és una tasca relativament simple, la descripció analítica de la generació del cicle límit associat presenta una elevada complexitat. Aquesta descripció combina l'anàlisi temporal i de freqüència per a justificar que l'espiral generada a partir de condicions inicials nul·les finalment convergeix en una el·lipse. Es demostra l'estabilitat en la generació del cicle límit a partir de l'anàlisi de la recurrència discreta resultant de la consideració de dos creuaments successius per zero del corrent de l'inductor després de completar un cicle d'oscil·lació. Aquest enfocament explica de forma correcta la generació d'espirals bidimensionals i tridimensionals en convertidors de segon i tercer ordre respectivament. Els convertidors ressonants auto-oscil·lants obtinguts mitjançant l'aplicació del mecanisme de commutació previ són sensibles a les pertorbacions de la tensió d'entrada o als canvis de càrrega, pel que és necessari introduir un llaç de regulació de tensió. Aquest fet requereix el modelat previ de la dinàmica del convertidor, que parteix d'una llei de commutació basada en la combinació lineal del corrent de l'inductor i la tensió del condensador. Relacionar les variacions de la constant associada a aquesta combinació lineal amb els canvis de la freqüència de commutació és un aspecte clau del modelat, el qual es duu a terme per a convertidors de segon ordre. El llaç de control resultant mostra un gran ample de banda i una major robustesa que els controladors convencionals.En esta tesis se presenta el funcionamiento auto-oscilante de convertidores resonantes, producido por el uso apropiado del signo de la corriente del inductor de entrada como mecanismo de cambio de la polaridad de la tensión de entrada. De esta forma, la corriente de entrada y el primer armónico de la tensión de entrada están en fase, lo que asegura un factor de potencia unitario en estado estacionario. Este hecho confiere una naturaleza de resistor libre de pérdidas a la descripción del convertidor como bipuerto. Se comprueba que este mecanismo de generación de la auto-oscilación es efectivo en estructuras de segundo, tercer y cuarto orden. Aunque la creación de la auto-oscilación es una tarea relativamente simple, la descripción analítica de la generación del ciclo límite asociado presenta una elevada complejidad. Esta descripción combina análisis temporal y de frecuencia para justificar que la espiral generada a partir de condiciones iniciales nulas finalmente converge en una elipse. Se demuestra la estabilidad en la generación del ciclo límite a partir del análisis de la recurrencia discreta resultante de la consideración de dos cruces sucesivos por cero de la corriente del inductor después de completar un ciclo de oscilación. Este enfoque explica de forma correcta la generación de espirales bidimensionales y tridimensionales en convertidores de segundo y tercer orden respectivamente. Los convertidores resonantes auto-oscilantes obtenidos mediante la aplicación del mecanismo de conmutación previo son sensibles a las perturbaciones de la tensión de entrada o a los cambios de carga, por lo que es necesario introducir un lazo de regulación de tensión. Ello requiere el modelado previo de la dinámica del convertidor, que parte de una ley de conmutación basada en la combinación lineal de la corriente del inductor y la tensión del condensador. Relacionar las variaciones de la constante asociada a esta combinación lineal con los cambios de la frecuencia de conmutación es un aspecto clave del modelado, el cual se lleva a cabo para convertidores de segundo orden. El lazo de control resultante exhibe un amplio ancho de banda y una mayor robustez que los controladores convencionales.In this thesis, self-oscillation in resonant converters is generated by the appropriate use of the input inductor current zero-crossings to change the polarity of the input voltage. As a result, the input current and the first harmonic of the input voltage are in phase, which ensures a unity power factor to the steady-state operation of the resonant converter. This fact confers a nature of loss-free resistor (LFR) on the two-port description of the converter. The self-oscillation generating mechanism is proven to be effective in second, third and fourth order structures. Although the self-oscillation generation is a relatively simple task, the analytical description of the generation is more involved. It combines time-domain and frequency-domain analyses to justify that a spiral starting from zero initial conditions eventually converges into an ellipse that corresponds to the steady-state behavior of the limit cycle. The stability of the generation is demonstrated by proving the stability of the resulting discrete recurrence considering two successive zero-crossings of the input inductor current after completing a generic oscillation cycle. This approach successfully explains the generation of two-dimension and three-dimension spirals in second and third order converters respectively. Self-oscillating resonant converters with the previous mechanism to generate oscillations are a simple procedure to transmit power but they are sensitive to input voltage perturbations or load changes. Hence, a voltage regulation loop has to be added. Inserting a voltage regulation loop requires modeling the dynamic behavior of the self-oscillating resonant converter whose switching law is a linear combination of inductor current and capacitor voltage. Relating the variations of the constant of that linear combination to the changes of the switching frequency is the key aspect of the modeling, which is carried out for second order converters. The resulting closed-loop regulation exhibits larger bandwidth and a better robustness degree than conventional controllers

Load Modeling and Evaluation of LEDs for Hardware Test Bed Application

The lighting industry was revolutionized with the emergence of LED lighting. Over the last 15 years, LED lighting device sales and utilization have grown immensely. The growth and popularity of LEDs is due to improved operation of the device when compared to previous lighting technologies. Efficient performance of the device is critical due to the growth of global energy consumption. As nonrenewable generation fuel is finite, utilities have begun the transition to renewable energy generation. Generation and distribution systems become inherently complex to comprehend and maintain with incorporation of emerging supply and load technologies. With the unprecedented growth of LED bulbs, there are concerns regarding the impact of their integration on power systems. In determination of the effects, which LED bulb adoption posed within the power grid, investigation of this device as a grid-load was pursued. This thesis reviews existing studies pertaining to LEDs and power grid load modeling methodologies. Load modeling aids in establishing a balance between energy generation and consumption, comprehensively characterizing relationships between electrical generation, transmission, distribution, and loads. Due to the complexities of large networked systems, device load models are constructed and aggregated in emulation of the interactive relationships throughout the power grid. This thesis includes a study of preestablished LED bulb ZIP load models and formulation of a component-based load model for improved characterization of a conventional LED lighting device. Load modeling was conducted with reference to the UTK HTB, for future integration and improved grid emulation. Factors, such as shape, size, illumination, and the power rating of popular LED bulbs is examined. Through investigation of typical LED bulb topologies, a model is formulated, in representation of device behavior as a load. The established load model’s characteristics are tested with comparison to physical device operation in a laboratory environment. The LED bulb component-based model is simulated under dynamic conditions in portrayal of device behavior under fault scenarios. An interactive interface is formulated for simulation of load behavior throughout grid level events. Detailed analysis of data and methods of implementation is provided, in characterization of the LED bulb’s load profile