基于Freescale单片机的电池管理系统设计

为了实现电动汽车电池的实时监控,在研究了锂离子电池特点的基础上,提出了一种用于混合动力汽车的分布式电池管理系统。其中,硬件系统包括电源模块、基于Freescale系列单片机的主控制模块和子模块、均衡模块以及CAN总线通信模块等;软件系统包括基于下溢中断的数据采集与处理、SOC估算、均衡处理和CAN通信等任务。     

Maximizing the Lifetime of Embedded Systems Powered by Fuel Cell-Battery Hybrids

Fuel cell (FC) is a viable alternative power source for portable applications; it has higher energy density than traditional Li-ion battery and thus can achieve longer lifetime for the same weight or volume. However, because of its limited power density, it can hardly track fast fluctuations in the load current of digital systems. A hybrid power source, which consists of a FC and a Li-ion battery, has the advantages of long lifetime and good load following capabilities. In this paper, we consider the problem of extending the lifetime of a fuel-cell-based hybrid source that is used to provide power to an embedded system which supports dynamic voltage scaling (DVS). We propose an energy-based optimization framework that considers the characteristics of both the energy consumer (the embedded system) and the energy provider (the hybrid power source). We use this framework to develop algorithms that determine the output power level of the FC and the scaling factor of the DVS processor during task scheduling. Simulations on task traces based on a real-application (Path Finder) and a randomized version demonstrate significant superiority of our algorithms with respect to a conventional DVS algorithm which only considers energy minimization of the embedded system.      

Failure modes on low voltage power MOSFETs under high temperature application

HEV (hybrid electrical vehicle) is one of the harshest applications for standard technology of power devices and converters. High temperature capability and passive/active thermal cycle ageing must be evaluated. The authors present first results on ageing and failure modes for a 75 V/350 A MOSFET module from a low voltage/cycled DC current test bench. The module is without base plate and bond wires are used for electrical connections. For this kind of low voltage and high current module, paper shows that the principal modes of failure relate to the environment close to the chip (connections and passivations).     

Performance comparison of a fuel cell-battery hybrid powertrain and a fuel cell-ultracapacitor hybrid powertrain

This paper studies two hybrid power systems for vehicle applications: a fuel cell-battery hybrid powertrain and a fuel cell-ultracapacitor hybrid powertrain. First, the characteristics of fuel cell, battery, and ultracapacitor as power sources are summarized. Then the configurations of the two types of hybrid fuel cell powertrains are presented. Finally, example hybrid powertrains are designed and simulated using ADVISOR. The simulation results indicate that ultracapacitors can more effectively assist the fuel cell to meet the vehicle power demand and help achieve a better performance and a higher fuel economy.     

Stretchable Electrode Based on Laterally Combed Carbon Nanotubes for Wearable Energy Harvesting and Storage Devices

Carbon nanotubes (CNTs) are a promising material for use as a flexible electrode in wearable energy devices due to their electrical conductivity, soft mechanical properties, electrochemical activity, and large surface area. However, their electrical resistance is higher than that of metals, and deformations such as stretching can lead to deterioration of electrical performances. To address these issues, here a novel stretchable electrode based on laterally combed CNT networks is presented. The increased percolation between combed CNTs provides a high electrical conductivity even under mechanical deformations. Additional nickel electroplating and serpentine electrode designs increase conductivity and deformability further. The resulting stretchable electrode exhibits an excellent sheet resistance, which is comparable to conventional metal film electrodes. The resistance change is minimal even when stretched by ≈100%. Such high conductivity and deformability in addition to intrinsic electrochemically active property of CNTs enable high performance stretchable energy harvesting (wireless charging coil and triboelectric generator) and storage (lithium ion battery and supercapacitor) devices. Monolithic integration of these devices forms a wearable energy supply system, successfully demonstrating its potential as a novel soft power supply module for wearable electronics.     

Instrumentation design for high-voltage electrical injury studies

The experimental study of high-power electrical injuries requires special devices to protect personnel and data recording instruments. A power distribution system is described which was designed to apply 500-20000 V and currents up to 100 A to an experimental preparation and a measurement system for recording 0.02-200.0 V at local sites in the preparation. Data collection and storage are automated with analog and digital devices that minimize personnel contact. For personnel safety, all recording instruments are isolated from the power distribution system by battery-driven standby power supplies and from the experimental high voltages by fiber optic data links. Current-triggering and- interruption mechanisms allow variable-duration voltage applications as short as 25 ms. These applications are also synchronized to the electrocardiogram and can be made to occur during any part of the cardiac cycle     

一种新型电动车超级电容-蓄电池复合电源系统

针对目前电动车续驶里程短、电池易老化、爬坡能力差、能量回收效率低的缺陷,研究以比功率高、循环寿命长的超级电容作为辅助电源,实现了一种新型超级电容-蓄电池复合电源系统.从超级电容-蓄电池系统的结构出发,对电动车的行驶工况进行了具体分析,构建了超级电容充电模型和超级电容-蓄电池复合电源系统模型.仿真和实际试验结果表明,该复合电源系统能有效回收制动能量,从而使蓄电池的低能量密度和低功率密度等缺陷得到弥补,进而提高电动车动力性能和电能的利用率,使电动车的续驶里程增长,能有效地降低蓄电池电压和电流幅值波动,延长蓄电池的使用寿命.     

A Multiple-Port Three-Level DC/DC Converter for HESS with Power Sharing in DC Microgrids

In order to reduce the volume, weight and cost of conventional hybrid energy storage system (HESS) while properly exploring the complementary features of different energy storage devices for DC microgrid applications, this paper proposes a multiple-port three-level DC/DC converter. It possesses multiple ports sharing one front-end three-level DC/DC converter with an inductor and supercapacitor bank. Different types of batteries and/or multiple battery banks can be interfaced through the multiple terminals. Such a converter structure facilitates the cooperation of different energy storage devices to satisfy various power demands of DC microgrids with intermittent renewable generation plants. Moreover, the proposed structure allows power sharing among different energy storage devices, which enables more efficient cooperation of different battery banks or different types of batteries. Experimental results are presented to verify the efficacy of the proposed converter structure and its control.     

A Hybrid Supercapacitor Fabricated with a Carbon Nanotube Cathode and a TiO2–B Nanowire Anode

Recently, a new hybrid supercapacitor, integrating both the advantages of supercapacitors and lithium‐ion batteries, was proposed and rapidly turned into state‐of‐the‐art energy‐storage devices with a high energy density, fast power capability, and a long cycle life. In this paper, a new hybrid supercapacitor is fabricated by making use of the benefits of 1D nanomaterials consisting of a carbon nanotube (CNT) cathode and a TiO₂–B nanowire (TNW) anode, and the preliminary results for such an energy‐storage device operating over a wide voltage range (0–2.8 V) are presented. The CNT–TNW supercapacitor is compared to a CNT–CNT supercapacitor, and discussed with regards to available energy densities, power capabilities, voltage profiles, and cycle life. On the basis of the total weight of both active materials, the CNT–TNW supercapacitor delivers an energy density of 12.5 W h kg^–1 at a rate of 10 C, double the value of the CNT–CNT supercapacitor, while maintaining desirable cycling stability. The combination of a CNT cathode and a TNW anode in a non‐aqueous electrolyte is proven to be suitable for high‐performance hybrid supercapacitor applications; this can reasonably be assigned to the interesting synergistic effects of the two nanomaterials. It is hoped that the results presented in this study might renew interest in the design of nanomaterials that are applicable not only to hybrid supercapacitors, but also to energy conversion and storage applications of the future.     

Design and New Control of DC/DC Converters to Share Energy Between Supercapacitors and Batteries in Hybrid Vehicles

In this paper, the authors propose the supercapacitor integration strategy in a hybrid series vehicle. The designed vehicle is an experimental test bench developed at the Laboratory of Electrical Engineering and Systems (L2ES) in collaboration with the Research in Electrical Engineering and Electronics Center of Belfort (CREEBEL). This test bench currently has two diesel motors (each connected to one alternator) and lead-acid batteries with a voltage rating of 540 V and a fluctuation margin between $+$12% and $-$20% of the rated voltage. The alternators are connected to the dc link by rectifiers. An original strategy of the supercapacitor integration in this vehicle with their control is presented to find a better compromise between the dimensions of the embarked devices, the share energy efficiency, the dynamics of the supply, and the electric power storage. The supercapacitor packs are made up of two modules of 108 cells each and present a maximum voltage of 270 V. The main objective is to provide a peak power of 216 kW over 20 s from supercapacitors to the dc link. Various topologies of dc/dc converters are presented with effective methodologies of electric power management in the hybrid vehicle.      

Power Semiconductor Devices for Hybrid, Electric, and Fuel Cell Vehicles

Power semiconductor devices are key components in all power electronic systems, particularly in hybrid, electric, and fuel cell vehicles. This paper reviews the system requirement and latest development of power semiconductor devices including IGBTs, freewheeling diodes, and advanced power module technology in relating to electric vehicle applications. State-of-the-art silicon device technologies, their future trends, and theoretical limits are discussed. Emerging wide bandgap semiconductor devices such as SiC devices and their potential applications in electric vehicles are also reviewed     

A Compact Digitally Controlled Fuel Cell/Battery Hybrid Power Source

A compact digitally controlled fuel cell/battery hybrid power source is presented in this paper. The hybrid power source composed of fuel cells and batteries provides a much higher peak power than each component alone while preserving high energy density, which is important and desirable for many modern electronic devices, through an appropriately controlled dc/dc power converter that handles the power flow shared by the fuel cell and the battery. Rather than being controlled to serve only as a voltage or current regulator, the power converter is regulated to balance the power flow to satisfy the load requirements while ensuring the various limitations of electrochemical components such as battery overcharge, fuel cell current limit (FCCL), etc. Digital technology is applied in the control of power electronics due to many advantages over analog technology such as programmability, less susceptibility to environmental variations, and low parts count. The user can set the FCCL, battery current limit, and battery voltage limit in the digital controller. A control algorithm that is suitable for regulating the multiple variables in the hybrid system is described by using a state-machine-based model; the issues about embedded control implementation are addressed; and the large-signal behavior of the hybrid system is analyzed on a voltage–current plane. The hybrid power source is then tested through simulation and validated on real hardware. This paper also discusses some important issues of the hybrid power source, such as operation under complex load profiles, power enhancement, and optimization of the hybrid system. The design presented here can not only be scaled to larger or smaller power capacities for a variety of applications but also be used for many other hybrid power sources.     

Energy Storage Systems for Automotive Applications

The fuel efficiency and performance of novel vehicles with electric propulsion capability are largely limited by the performance of the energy storage system (ESS). This paper reviews state-of-the-art ESSs in automotive applications. Battery technology options are considered in detail, with emphasis on methods of battery monitoring, managing, protecting, and balancing. Furthermore, other ESS candidates such as ultracapacitors, flywheels and fuel cells are also discussed. Finally, hybrid power sources are considered as a method of combining two or more energy storage devices to create a superior power source.     

Modeling of Zinc Bromide Energy Storage for Vehicular Applications

Energy storage devices such as lithium-ion and nickel-metal hydrate batteries and ultracapacitors have been considered for utilization in plug-in hybrid electric vehicles (HEVs) and HEVs to improve efficiency and performance and reduce gas mileage. In this paper, we analyze and model an advanced energy storage device, namely, zinc bromide, for vehicular applications. This system has high energy and power density, high efficiency, and long life. A series of tests has been conducted on the storage to create an electrical model of the system. The modeling results show that the open-circuit voltage of the battery is a direct function of the battery's state of charge (SOC). In addition, the battery internal resistance is also a function of SOC at constant temperature. A Kalman filtering technique is also designed to adjust the estimated SOC according to battery current.      

4×25Gb/s光电收发一体模块封装的设计与实现

光电收发模块的性能对整个通信系统质量至关重要.设计一个包括光电器件、封装结构等参数的光电协同链路仿真系统,首先从系统封装方案、版图和信号完整性等方面进行设计优化,获得封装结构的电学参数;其次,对光电器件参数进行优化提取,并建立一个包括封装结构电学参数对系统的性能影响的光电协同的仿真链路,通过光电协同链路仿真提前对模块进...     

Inrush current estimation and hot-swapping for safe parallel battery pack

ABSTRACT

Batteries used in electric vehicles and microgrid applications use battery modules connected in series to satisfy the voltage required for each system, and battery modules are connected in parallel to increase capacity. In this parallel connected system, in order to disconnect and reconnect a specific battery module or to reconnect a new battery module, the battery module to be newly connected should have a small state of charge (SOC) difference from the existing battery modules. In particular, when a new battery is to be connected under a load current, there is a problem that excessive inrush current may occur in a specific battery module due to the load current distributed to each module and the current due to the SOC difference. Therefore, in this paper, we propose a method of estimating the inrush current through an equivalent electrical modelling analysis for the case where a battery module is newly added in a system in which the battery modules are connected in parallel. In addition, the power management algorithm for the battery pack system with inrush current estimation is presented. The proposed method is validated through simulations and experiments of a battery pack system in which 10 battery modules of 710V and 120Ah are connected in parallel.     

Multifunctional High‐Power Sources for Smart Contact Lenses

Powering an electrical contact lens is a significant challenge for wearable applications such as augmented reality displays and iontophoretic drug delivery to the eye. Here a hybrid power generation device is developed comprising a wireless power transfer system and a bioabsorbable metal–air primary battery, which provides a multifunctional direct current (DC) and/or alternating current (AC) output. The DC power is generated by Zn loop anode and a bilirubin oxidase (BOD) biocathode in an artificial tear. The Zn‐based loop anode is also used as the antenna of a wireless power transfer system that results in high power transfer efficiency of 17.6% at 13.56 MHz. The wireless‐powered AC voltage is boosted from 1.5 to 1.5 V + 0.5 V_pp by a DC offset, enabling red light‐emitting diode (LED) emission. Furthermore, the hybrid AC and DC offset voltages are boosted to 2.3 V + 0.5 V_pp by a capacitive booster circuit that provides blue LED emission. No hydrogen evolution or pH change is observed in the tear electrolyte. The present hybrid power source can potentially power wearable electronics in body fluids.     

Current Technology of Supercapacitors: A Review

A supercapacitor is a solid-state device that can store electrical energy in the form of charges. It represents an advancement in the field of energy storage, as it overcomes many of the shortcomings of batteries. This paper presents an overview of the various types of supercapacitors, electrode materials, and electrolytes, and the future of supercapacitors. Due to their high storage capacity, supercapacitors are commonly used in portable electronic devices such as MP3 players and mobile phones, and in hybrid vehicles and other applications. In electrical and hybrid vehicles, supercapacitors are increasingly used as provisional energy storage for regenerative braking. Various materials are used in electrodes to boost the performance of the supercapacitor. This review presents details regarding the materials and electrolyte, and the improvements in the field of supercapacitors.     

电动车混合电源系统设计

设计了一种用于电动车的混合电源系统。该系统以蓄电池为主电源,采用具有双电层结构的超级电容器为辅助能源。利用单片机控制电动车在不同状态选择不同电源进行供电。以200 kg的人与车沿着仰角为30°,落差为6 m的坡度行驶进行实验,可增加130 m的行驶距离。这表明该混合电源有效地增加了电动车的行驶里程,同时可延长蓄电池的使用寿命,具有很大的现实推广意义。     

A virtual prototype for a hybrid electric vehicle

A virtual prototype of a hybrid electric vehicle (HEV) is created within the virtual test bed (VTB) environment, which has been developed for modeling, simulation, analysis and virtual prototyping of large-scale multi-technical dynamic systems. Attention is focused on the electric system, which is composed of (i) a fuel cell system as a prime power source, (ii) battery and super capacitor banks as energy storage devices for high and intense power demands, (iii) DC-to-DC power converters to control the flow of power, (iv) a three-phase inverter-fed permanent magnet synchronous motor as a drive, and (v) a common DC bus. The simulation of the proposed system is conducted using two types of driving cycles. These are: (i) rapid acceleration and deceleration, and (ii) Federal Urban Driving Schedule (FUDS). The parameter values chosen for the components and the numerical results obtained by simulation are consistent with the practical HEV applications.