High Performance Power Management Integrated Circuits for Portable Devices

abstract: Portable devices often require multiple power management IC (PMIC) to power different sub-modules, Li-ion batteries are well suited for portable devices because of its small size, high energy density and long life cycle. Since Li-ion battery is the major power source for portable device, fast and high-efficiency battery charging solution has become a major requirement in portable device application. In the first part of dissertation, a high performance Li-ion switching battery charger is proposed. Cascaded two loop (CTL) control architecture is used for seamless CC-CV transition, time based technique is utilized to minimize controller area and power consumption. Time domain controller is implemented by using voltage controlled oscillator (VCO) and voltage controlled delay line (VCDL). Several efficiency improvement techniques such as segmented power-FET, quasi-zero voltage switching (QZVS) and switching frequency reduction are proposed. The proposed switching battery charger is able to provide maximum 2 A charging current and has an peak efficiency of 93.3%. By configure the charger as boost converter, the charger is able to provide maximum 1.5 A charging current while achieving 96.3% peak efficiency. The second part of dissertation presents a digital low dropout regulator (DLDO) for system on a chip (SoC) in portable devices application. The proposed DLDO achieve fast transient settling time, lower undershoot/overshoot and higher PSR performance compared to state of the art. By having a good PSR performance, the proposed DLDO is able to power mixed signal load. To achieve a fast load transient response, a load transient detector (LTD) enables boost mode operation of the digital PI controller. The boost mode operation achieves sub microsecond settling time, and reduces the settling time by 50% to 250 ns, undershoot/overshoot by 35% to 250 mV and 17% to 125 mV without compromising the system stability.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

High efficiency multi power source control constant current/constant voltage charger lithium-ion battery based on the buck converter

This paper proposes the design and simulation of a constant current/constant voltage (CC/CV) multi-power source lithium-ion (Li-ion) battery charging system based on the Buck typology. The aim of this new design that uses the Buck converter with multiple numbers of sources, is to provide sufficient energy for battery charging, with an analog switch to select the active source that has priority to guarantee the continuity of the charging without interruption. As well as the transition between the charging modes is smooth that is provided by a multiplexed switcher. At the same time is increases the efficiency of the system by using fewer power dissipation components and low output ripple. The obtained results show that the Li-ion battery can be successfully charged without reducing its life cycle. In the global, those technics allow reducing financial costs. This allows such a solution to be well-positioned in the industrial market (electric vehicles (EV) and medical)

A new high speed charge and high efficiency Li-Ion battery charger interface using pulse control technique

A new Li-Ion battery charger interface (BCI) using pulse control (PC) technique is designed and analyzed in this paper. Thanks to the use of PC technique, the main standards of the Li-Ion battery charger, i.e. fast charge, small surface area and high efficiency, are achieved. The proposed charger achieves full charge in forty-one minutes passing by the constant current (CC) charging mode which also included the start-up and the constant voltage mode (CV) charging mode. It designed, simulated and layouted which occupies a small size area 0.1 mm2 by using Taiwan Semiconductor Manufacturing Company 180 nm complementary metal oxide semi-conductor technology (TSMC 180 nm CMOS) technology in Cadence Virtuoso software. The battery voltage VBAT varies between 2.9 V to 4.35 V and the maximum battery current IBAT is 2.1 A in CC charging mode, according to a maximum input voltage VIN equal 5 V. The maximum charging efficiency reaches 98%

Traction and charging systems for an electric motorcycle

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e Computadores (área de especialização em Electrotecnia e Sistemas de Energia)With the current mobility paradigm, it is proven that excessive energy consumption and low energy efficiency are harming the planet and deteriorating human life conditions. Therefore it is required to substitute Internal Combustion Engines (ICEs) for electric motors and consequently shift gradually to fully electric vehicle (EV) fleets. The electrification of mobility is one of the most researched topics in all technology fields. These efforts put society closer to achieve energy sustainability and reduce the negative human impact on the environment. With this, low energy consumption vehicles such as electric motorcycles (EMs) are a very viable solution to reduce energy consumption. Due to their low power and weight, EMs have high energy efficiency and are optimized for urban transit. In this context, it becomes necessary to develop systems and prototypes common to any EV. Therefore the focus of this thesis is to implement motor traction and battery charging systems for an EM. One of the most important characteristics of an electric traction system is the possibility of applying regenerative braking. Regenerative braking converts the mechanical energy, otherwise dissipated by conventional brakes, into reusable energy that is sent back to the batteries. This process occurs due to the operation of the traction system’s power converter and improves greatly the energy efficiency of the EV. Besides, is proposed that the traction system’s input is a hand accelerator that can control the motor speed/torque. The charging system acts as an interface between the power grid and the motorcycle system. In applications such as EV charging, it is important to ensure power quality in order to maintain the developed system and the power grid healthy. With this, the first stage of the charger is AC-DC rectification and besides regulating the DC-link voltage should also act as a Power Factor Corrector (PFC) and compensate current harmonics. Secondly, the charger system should be able to regulate and control the charging process by maintaining a constant current, voltage, or temperature. The charger should also ensure the battery’s safety, and offer the possibility of regulating the charging speed. This document, details the development of traction and charger systems from the state of the art research and topologies presentation, to the computational simulations, and respective experimental tests/validation.Com o paradigma da mobilidade é evidente que o consumo excessivo de energia proveniente de combustíveis fosseis está a prejudicar o planeta. Por conseguinte, é necessário substituir os Motores de Combustão Interna (MCI) por motores eléctricos e, consequentemente, transitar gradualmente para frotas de veículos 100% elétricos (VE). A eletrificação da mobilidade é um dos tópicos com mais investimento em investigação de todos os campos tecnológicos. Estes esforços aproximam a sociedade para alcançar a sustentabilidade energética e reduzir o impacto humano no ambiente através da extração de combustíveis fósseis. Com isto, veículos de baixo consumo energético, tais como motociclos eléctricos (ME), são uma solução muito viável. Devido à sua baixa potência e peso, os MEs possuem elevada eficiência energética e são optimizados para o trânsito urbano.. Neste contexto, torna-se necessário o desenvolvimento de sistemas e protótipos comuns a qualquer EV. Portanto, o foco desta dissertação é a implementação dos sistemas de tração para um motor e de carregamento de baterias para um ME. Uma das características mais importantes de um sistema de tracção elétrica é a possibilidade de aplicar travagem regenerativa. A travagem regenerativa converte a energia mecânica, de outro modo dissipada pelos travões convencionais, em energia reutilizável que é reenviada para as baterias. Este processo ocorre devido ao funcionamento do conversor do sistema de tracção e aumenta a eficiência energética do VE. Além disso, é proposto que o sistema de tracção seja controlado através de um acelerador manual que pode controlar a velocidade/torque do motor. O sistema de carregamento actua como interface entre a rede elétrica e o motociclo. Em aplicações como o carregamento de VEs, é importante assegurar a qualidade da energia tanto do sistema desenvolvido como da rede de elétrica. Com isto, a primeira fase do carregador, para além de regular a tensão DC, deve também actuar como corrector do factor de potência (PFC). Em segundo lugar, o sistema carregador deve ser capaz de regular e controlar o processo de carregamento mantendo uma corrente, tensão ou temperatura constantes. O carregador, para além de fazer a interface entre o DC-link e a bateria, deve oferecer a possibilidade de regular a taxa de carregamento. Este documento, detalha o desenvolvimento de sistemas de tracção e carregamento desde a investigação e apresentação das topologias mais utilizadas, até às simulações computacionais, e respectivos testes experimentais/validação

High-current integrated battery chargers for mobile applications

Battery charging circuits for mobile applications, such as smart phones and tablets, require both small area and low losses. In addition, to reduce the charging time, high current is needed through the converter. In this work, exploration of the Buck, the 3-Level Buck and the Hybrid Buck converter is performed over the input voltage, the total FET area and the load current. An analytical loss model for each topology is constructed and constrated by experimental results. In addition, packaging and bond wire impact on on-chip losses is analyzed by 3D modeling. Finally, a comparison between the topologies is presented determining potential candidates for a maximum on-chip loss of 2 W at output voltage of 4 V and 10 A of output current

Integrated DC-DC Charger Powertrain Converter Design for Electric Vehicles Using Wide Bandgap Semiconductors

Electric vehicles (EVs) adoption is growing due to environmental concerns, government subsidies, and cheaper battery packs. The main power electronics design challenges for next-generation EV power converters are power converter weight, volume, cost, and loss reduction. In conventional EVs, the traction boost and the onboard charger (OBC) have separate power modules, passives, and heat sinks. An integrated converter, combining and re-using some charging and powertrain components together, can reduce converter cost, volume, and weight. However, efficiency is often reduced to obtain the advantage of cost, volume, and weight reduction.An integrated converter topology is proposed to combine the functionality of the traction boost converter and isolated DC-DC converter of the OBC using a hybrid transformer where the same core is used for both converters. The reconfiguration between charging and traction operation is performed by the existing Battery Management System (BMS) contactors. The proposed converter is operated in both boost and dual active bridge (DAB) mode during traction operation. The loss mechanisms of the proposed integrated converter are modeled for different operating modes for design optimization. An aggregated drive cycle is considered for optimizing the integrated converter design parameters to reduce energy loss during traction operation, weight, and cost. By operating the integrated converter in DAB mode at light-load and boost mode at high-speed heavy-load, the traction efficiency is improved. An online mode transition algorithm is also developed to ensure stable output voltage and eliminate current oscillation during the mode transition. A high-power prototype is developed to verify the integrated converter functionality, validate the loss model, and demonstrate the online transition algorithm. An automated closed-loop controller is developed to implement the transition algorithm which can automatically make the transition between modes based on embedded efficiency mapping. The closed-loop control system also regulates the integrated converter output voltage to improve the overall traction efficiency of the integrated converter. Using the targeted design approach, the proposed integrated converter performs better in all three aspects including efficiency, weight, and cost than comparable discrete solutions for each converter

Design of a Two-Stage Level-Two Bidirectional On-Board Battery Charger for Plugin Vehicles

Depletion of fossil fuel reserves, increasing awareness of air pollution levels and continuous rise in gasoline prices are some of the major drives that have been revolutionizing the automotive industry since the last decade. These factors combined are causing conventional automobiles with internal combustion engines (ICE) to be replaced with plugin vehicles. The on-board rechargeable battery packs in plugin vehicles can be recharged by connecting to the utility grid using a plug. The energy stored in the on-board battery packs has attractive benefits for grid support, and this promotes the idea of Vehicle-to-Grid (V2G). V2G power transactions allow energy from the on-board battery packs to be sent back to the utility grid for support in peak shaving and provide reactive power compensation. One natural consequence that arises with the introduction of V2G is a sharp increase in the need for high-performance power electronic interface between the utility grid and the battery pack. Therefore, research on bidirectional battery chargers for plugin vehicles is imperative in order to aid in the promotion of V2G. This thesis focuses on the design and development in a two-stage level-two on-board bidirectional battery charger

Power Converters in Power Electronics

In recent years, power converters have played an important role in power electronics technology for different applications, such as renewable energy systems, electric vehicles, pulsed power generation, and biomedical sciences. Power converters, in the realm of power electronics, are becoming essential for generating electrical power energy in various ways. This Special Issue focuses on the development of novel power converter topologies in power electronics. The topics of interest include, but are not limited to: Z-source converters; multilevel power converter topologies; switched-capacitor-based power converters; power converters for battery management systems; power converters in wireless power transfer techniques; the reliability of power conversion systems; and modulation techniques for advanced power converters

High-Frequency Bidirectional DC-DC Converters for Electric Vehicle Applications

As a part of an electric vehicle (EV) onboard charger, a highly efficient, highly compact, lightweight and isolated DC-DC converter is required to enable battery charging through voltage/current regulation. In addition, a bidirectional on-board charger requires the DC-DC converter to achieve bidirectional power flow: grid-to-vehicle (G2V) and vehicle-to-grid (V2G). In this work, performance characteristics of two popular DC-DC topologies, CLLC and dual active bridge (DAB), are analyzed and compared for EV charging applications. The CLLC topology is selected due to its wide gain range, soft-switching capability over the full load range, and potential for a smaller and more compact size. This dissertation outlines the feasibility, analyses, and performance of a CLLC converter investigated and designed to operate at 1 MHz and 3.3 kW for EV onboard chargers. The proposed design utilizes the emerging wide bandgap (WBG) gallium nitride (GaN) based MOSFETs to enable high-frequency switching without sacrificing the conversion efficiency. One of the major challenges in MHz-level power converter design is to reduce the parasitic components of printed circuit boards (PCBs), which can cause faulty triggering of switches leading to circuit failure. An innovative gate driver is designed and optimized to minimize the effect of parasitic components, which includes a +6/-3 V driving logic enhancing the noise immunity of the system. Another challenge is the efficient design of magnetic components, which requires minimizing the impacts of skin and proximity effects on the transformer winding to reduce the conduction loss at high frequencies. A novel MHz-level planar transformer with adjustable leakage inductance is modeled, designed, and developed for the proposed converter. A comprehensive system level power loss analysis is completed and confirmed with the help of experimental results. This is the first prototype of a 3.3 kW power bidirectional CLLC converter operating at 1 MHz operating frequency with 400-450 V input voltage range, 250-420 V output voltage range. The experiment results have successfully validated the feasibility of the proposed converter conforming to the analysis carried out during the design phase. With an appropriate design of driving circuit and control signal, the prototype achieves a peak efficiency of 97.2% with 9.22 W/cm3 (151.1 W/in3) power density which is twice more power dense than other state-of-the-art isolated DC-DC converters