Air pollution is one of the world’s leading risk factors for death. And transportation is one of the largest pollution sources. Therefore, electrification becomes a necessary step in reducing air pollution and save lives. As a result, electric vehicles are becoming the future trend in automotive industries. However, there are still some of the concerns which stop consumers from purchasing electric vehicles. Charging faster and longer driving range are two factors that consumers care most. So how to solve these concerns? A high-efficiency charger could be one solution. Level 2 charger takes less time in charging than level 1. But with the lack of charging facilities right now, charging should be available in all situations. This thesis investigates a high-efficiency on-board charger (OBC) that could be used both at residences and at charging stations. The OBC is able to operate at a wide output battery range as well. High efficiency means low losses. Therefore, the proposed topology uses the least number of components to minimize the losses as much as possible. The efficiency is further optimized by using wide bandgap device Gallium Nitride. Since Gallium Nitride shows superior performance in high power applications. The proposed OBC combines a GaN-based bridgeless totem-pole PFC with a synchronous buck converter with innovative active filtering to allow a much smaller dc-link capacitance. The carefully designed passive components occupy less space and help improve power density. Film capacitors are used to replace the conventional electrolytic capacitors since the latter do not have good reliability for automotive applications. The proposed OBC is designed with small current ripple percentage and small output voltage ripple percentage. The simulation results show a high peak efficiency over 98% at both level 1 and level 2 charging mode. The power factor (PF) is over 0.998 and the total harmonic distortion percentage (THD %) is less than 5% at full load condition (3.3 kW). In one sentence, the charger is simple, high efficiency, works with a universal charging system, with a wide output range, and compact. / Thesis / Master of Applied Science (MASc)

This thesis is to design a Positive/Negative pulse battery charger with a high positive pulse current to charge battery quickly , The negative impulsive discharge current is used to accelerate chemical reaction between pole plates be response. Finally, there is a rest time to let charging effect uniform and to reduce temperature so as to last battery life cycle. The thesis uses dsp to control the single-stage Flyback converter charging battery then combine flyback DCM model and voltage follower control to increase efficiency. The chemical reaction of the negative pulse discharging mode. CMOS switch series connection resistance would speed up . Finally we join two-stage positive/negative pulse battery deep discharging to strengthen the lithium battery chemical reaction and efficient reduce the charging time ,it causes the fixed current charge able to enter more electric quantities until achieving 4.2v lithium battery's definition voltage sufficiently then transforms into the fixed voltage charge. this circuit has reached the goal of high-power Factor and quickly charging to extend life cycle of battery In order to understand the influence of positive/negative pulse ,we measure voltage, temperature and time period of charging and discharging in the experiment.

The first part of the work was dealing in general with switched power supply and types of battery chargers. The second part is made by my own design of microprocessor driven battery charger. The design is based on datasheets and recommended circuit connection. The electrical scheme and also the printed circuit board was designed in Eagle 5.11.0 design system. The battery charger is capable of charging these types of batteries: lead acid, NiMH, NiCd, LiPol a alkaline accumulators, and the maximal output current from charger is 3A. The software implementation and design are also part of this master‘s thesis.

The first part of the work was dealing in general with switched power supply and types of battery chargers. The second part is made by my own design of microprocessor driven battery charger. The design is based on datasheets and recommended circuit connection. The electrical scheme and also the printed circuit board was designed in Eagle 5.11.0 design system. The battery charger is capable of charging these types of batteries: lead acid, NiMH, NiCd, LiPol a alkaline accumulators, and the maximal output current from charger is 3A. The software implementation and design are also part of this master‘s thesis.

This report presents the process of design and implementation of a battery charger for a Li-ion battery. The development of this battery charger includes the component from Linear Technology LTC4015. This component integrates the functions of a battery charger configured as a buck (step-down) converter. This device must be integrated in a Printed Circuit Board with a specific design. Also, it must be configured using a microcontroller named Raspberry Pi, which also performs the measurements. The method of design is divided in two parts. One is focused on developing the printed circuit board, which includes the simulation of the device and the development of the PCB, and the second one is focused on developing the program used in the microcontroller to manage the operation of the LTC4015. The result is a charge controller device that can be used with different configurations with a buck converter topology. The different parts of the design process are the simulation, the design and the implementation. Each of these parts have a section of results in this report. The simulation section includes results obtained with LTSpice and the device LTC4020, which is a similar device to the LTC4015 but without the Maximum Power Point Tracking mode, which is not modelled in LTSpice. PV is the main power source considered to charge the battery, and is carefully studied in this project. The PV input is studied with LTSpice, first simulating the I-V curve of the schematic of the solar cell. Second, integrating a solar cell in the simulation of the LTC4015. Third, operating the device LTC4015 with a solar panel that is also characterized. The design section includes the electronic components used for the development of the board that integrates the charge controller, the LTC4015 in this case, based on the calculations performed for the requirements of the LTC4015. Finally, the implementation section includes the description of the board implemented but also the description of the configuration and measurement code. The conclusions presented in this report show that the LTC4015 is a battery buck charger with different functions that make it suitable to be used in different solar applications. Also, this report opens new future work lines, such as the full characterization of the board, the implementation of a test bench and the integration of the board in different applications for solar energy systems.

Lithium-ion batteries have been used extensively over the past two decades in the portable consumer electronics industry. More recently, Li-ion batteries have become candidates for much larger-scale applications such as electric vehicles and energy grid storage, which impose much more stringent requirements on batteries, especially in terms of cell lifetime. In order to develop batteries with improved lifetimes, a means of quickly and accurately evaluating battery life is required. The use of coulombic efficiency (CE) is an important tool in this regard, which provides a way to quantify parasitic reactions occurring within the cell. As more stable battery chemistries are developed, the rates of parasitic reactions occurring in the cell become reduced, and differences in CE among cells become increasingly smaller. In order to resolve these differences, charger systems must be developed which can measure CE with increased precision and accuracy. This thesis investigates various ways to improve the precision and accuracy of CE measurements. Using the high-precision charger (HPC) at Dalhousie University (built in 2009) as a starting point, a new prototype charger was built with several modifications to the design of the existing HPC. The effect of each of these modifications is investigated in detail to provide a blueprint for the development of next-generation charger systems. This prototype charger shows greatly improved precision and accuracy, with CE results that are approximately four times more precise than those of the existing HPC and over an order of magnitude more precise than high-end commercially available charger systems

This diploma thesis deals with battery charging. The thesis describes qualities and possi-bilities of lithium battery charging. The charger is independent on the input voltage and recharges batteries carefully. Due to a careful recharging process it is needed to measure the voltage at various cells of the battery and then balance this voltage. Since the charger is to be implemented in a robot, it is needed to switch the operation from an external source and the battery. The first part of the project deals with qualities of batteries and the way of their recharging. In the second part I design an individual blocks charger. In the third part I deal with a communication with a computer charger and data visualization. And in the last part I designed a program for the charger.

This report will investigate and go through the steps required to develop several concepts for afuel cell-powered battery charger to be used in the field by Husqvarna AB. The purpose is togather information about available fuel cell technologies and provide an understanding of howthese concepts could look in both the present and the future. Through an examination ofprevious studies in the field, it has been determined that the most suitable types of fuel cells arePEMFC and DMFC. Additional information has been collected from various sources, such asthe internet, books, and through contact with fuel cell manufacturers and Husqvarna AB.Three different fuel cells were chosen, each of which was assigned a unique concept. Two ofthese concepts are more future-oriented, aiming to provide a better idea of how the productcould look if the requirements are strictly followed. The third concept demonstrates how theproduct would need to appear and the features required to be more suitable for the present.Finally, a comparison was made where the technical characteristics of concepts were pittedagainst each other, and weighted requirements showed that the concept containing EFOY´s12000 pro fuel cell moved forward. / Denna rapport kommer att utreda och gå igenom de moment som krävs för att komma fram tillett flertal koncept för en bränslecellsdriven batteriladdare som ska användas ute på fältet förföretaget Husqvarna AB. Syftet är att samla information om tillgängliga teknologier förbränsleceller och ge en bild av hur dessa koncept skulle kunna se ut både i framtiden och idagsläget. Genom att undersöka tidigare studier inom ämnet har det bestämts att de mestlämpliga typerna av bränsleceller är PEMFC och DMFC. Ytterligare information har samlats infrån olika källor, såsom internet, böcker och genom kontakt med företag som producerarbränsleceller samt Husqvarna AB.Tre olika bränsleceller valdes, (EFOY 12000 pro, IE-LIFT 1T/1U och IE-LIFT 804), där var ochen av dessa fick varsitt unikt koncept. Två av dessa koncept är mer inriktade på framtiden föratt ge en bättre bild av hur produkten skulle kunna se ut om man följer kravspecifikationenstrikt. Det tredje konceptet visar bättre hur produkten skulle behöva se ut och vilka funktionersom skulle behövas för att vara mer lämplig för produktion i dagsläget.Slutligen gjordes en jämförelse där konceptens tekniska egenskaper ställdes mot varandra därviktade krav visade att konceptet som innehöll EFOY’s 12000 pro bränslecell gick vidare.

Στην παρούσα διπλωματική εργασία γίνεται επισκόπηση των βασικών τεχνολογιών επαναφορτιζόμενων και μη μπαταριών και στη συνέχεια μέσω της τεχνολογίας ενσωματωμένων συστημάτων παρουσιάζεται η υλοποίηση με λογισμικό πάνω σε έναν μικροελεγκτή ARM7 της Analog Devices, ενός φορτιστή μπαταριών τύπου NiMH. / In the following diploma thesis appears an overview of basic technologies of the rechargeable and non rechargeable batteries and then through technology of embedded systems shows the implementation with software on a microcontroller ARM7 of Analog Devices, of a NiMH battery charger.

Thanks to the advance in CMOS technology, an extensive category of applications has been migrated from traditional BJT-based processes. System-on-a-Chip (SoC) realization of digital, analog, and even high voltage devices is now a reality. To address the challenge imposed by integrating analog and high voltage devices in standard CMOS processes, this thesis aims at the design of three specific topics in particular. With regard to the contents of the thesis, first of all, the theory of linear-in-dB automatic gain control (AGC) is discussed. In succession, a linear-in-dB variable gain amplifier (VGA) is mentioned. The implementation of a Feed-forward Output Swing Prediction AGC featuring a Prediction Parallel-Detect Single-Store Peak Detector (PDSSPD) and a High Input/Output Swing VGA is also described. Furthermore, a digitally programmable gain amplifier for a ZigBee wireless receiver is also mentioned. In response to the advent of CMOS-compatible high voltage tolerant Bipolar-CMOS-DMOS (BCD) process, an operational amplifier for level converting operation is disclosed. A 60-V Li-ion battery charger has also been proposed, along with a novel battery charge mode, namely, the incremental charge (IC) mode. Practical issues regarding the high voltage tolerant BCD process is also briefly discussed. Finally, a backplane transmitter featuring pre-emphasis and a receiver utilizing decisive feedback equalization (DFE) designed for CIC MorPack technology are presented. When packaged in a Leadless Ceramic Carrier (LCC) package, the transmitter can transmit up to 500 Mbps and the receiver can receive up to 125 Mbps, both through DuPont connectors without impedance matching.