Market mature 1998 hybrid electric vehicles

Beginning in 1990, the major automotive passenger vehicle manufacturers once again re-evaluated the potential of the battery powered electric vehicle (EV). This intensive effort to reduce the battery EV to commercial practice focused attention on the key issue of limited vehicle range, resulting from the low energy density and high mass characteristics of batteries, in comparison to the high energy density of liquid hydrocarbon (HC) fuels. Consequently, by 1995, vehicle manufacturers turned their attention to hybrid electric vehicles (HEV). This redirection of EV effort was highlighted finally in 1997, at the 57th Frankfurt Motor Show, the Audi Duo parallel type hybrid was released for the domestic market as a 1998 model vehicle. Also at the 1997 32nd Tokyo Motor Show, Toyota Hybrid System (THS) Prius was released for the domestic market as a production 1998 model vehicle. This paper presents a comparative analysis of the key features of these two 1998 model year production hybrid systems. Among the conclusions, two issues are evident: one, the major manufacturers have turned to the hybrid concept in their search for solutions to the key EV issues of limited range; and, heating/air conditioning; and two, the focus is now on introducing hybrid EV for test marketing domestically     

Commercialization of advanced batteries

Mader & Associates has been working as a contractor for the South Coast Air Quality Management District (District) as well as domestic and off-shore battery developers for the past several years. During this period, it has performed various assessments of advanced battery technology as well as established the Advanced Battery Task Force. The following paper is Mader's view of the status of battery technologies that are competing for the electric vehicle (EV) market being established by the California Air Resources Board's Zero Emission Vehicle (ZEV) mandate. The ZEV market is being competed for by various advanced battery technologies. And, given the likelihood of modifications to the Mandate, the most promising technologies should capture the following market share during the initial 10 years: lead-acid-8.4%; nickel metal hydride-50.8%; sodium nickel chloride-7.8%; and lithium ion-33.0%. However, today there is much less certainty associated with EV market prediction due to changes in the ZEV regulations     

Charge measurement circuit for electric vehicle batteries

Calculating the state of charge (SOC) of an electric vehicle (EV) battery is an inherently error prone process that depends on several variables. However, the accuracy of the required charge flow measurements can be greatly improved by using a voltage to frequency (V/F) converter in conjunction with a digital counter to integrate the measured battery current.     

Considerations regarding the comparison of traction batteries

S.E.A. has been developing, since 1983, the zinc-flow-battery to be ready for mass production. In 1993 the Boston based Power Cell Corporation (PCC) acquired S.E.A. and the new company intends to erect a facility to produce 150.000 kWh at the end of 1994. Since 1985 zinc-flow-batteries are used to power electric-vehicles in capacities between 5 kWh and 45 kWh at voltages between 48 V and 216 V. A 22.5 kWh/96 V battery assembled in a Fiat-Panda is shown, which achieves 260 km per charge at 50 km/h constant. This Panda participated in several rallies. A purpose designed 15 kWh/144 V battery for the Hotzenblitz-EV is also shown, which demonstrates the design-flexibility of the battery. The battery is mounted from underneath the car body between the four wheels and does not consume valuable space in the front or rear of the car. This position is a significant contribution to the safety of passengers. Mass production for this EV is foreseen in 1995. About 50,000 kms of testing experience partially in direct comparison with originally assembled lead acid batteries showed results with zinc-flow-battery equipped EVs, which were significant better than was expected. Referring to about the same battery weight a two- to threefold range was experienced with the zinc-flow-system independent of the driving cycle and independent of the battery capacity compared     

Field evaluation of Honda's EV PLUS battery packs

The EV PLUS demonstration program provides an opportunity to evaluate battery life while gaining expertise in managing Ni-MH battery technology under real-world conditions. Since individual customers use the vehicles, Honda developed a battery service and evaluation system convenient to customers, yet not burdensome to dealer service. This paper discusses the method of detection of low battery capacity, the technique used to convey this information to users, the bench evaluation system of returned batteries, and explains how the analysis is utilized to enhance the EV PLUS' battery control strategy.     

基于IPSO-Elman神经网络的飞机客舱能耗预测

为了提高飞机客舱使用地面空调制冷时客舱能耗的预测精度,提出了一种改进的粒子群优化（IPSO）Elman神经网络的飞机客舱能耗预测模型。依据对算法中惯性权重与学习因子的收敛域分析,得出了二者合理的取值范围,将粒子到全局最优位置间距离与参数的取值范围相结合,构造了惯性权重与学习因子的动态调节函数,对其进行非线性的动态调节,并引入了变异因子,提出了一种跳出局部最优的策略,防止粒子群优化（PSO）陷入局部最优。将IPSO-Elman应用于Boeing738飞机客舱能耗预测中,与PSO-Elman、Elman算法进行性能比较,仿真结果表明基于IPSO-Elman的客舱能耗预测模型在预测精度和收敛速度方面均有一定的提升。该研究结果为飞机客舱能耗预测模型的建立提供了理论依据,对飞机地面空调的节能与机场电能合理调配提供了支持。     

Heating and cooling battery electric vehicles-the final barrier

Battery electric vehicles (EVs) present a particular challenge to the development of more efficient and effective heating and cooling systems for automotive applications. Because heating-ventilating-air-conditioning (HVAC) systems are electrically powered, vehicle range is reduced when the HVAC system is operating. The alternative solutions to HVAC battery electric vehicles are identified and evaluated. These include a basis for determining HVAC boundary design assumptions and showing mathematical methods for estimating the HVAC load and energy requirements, and evaluation of the new European and Japanese approaches to wintertime heating, such as NaS battery, motor and component waste heat recovery, electric seat warmer, radiant foot warmer, electric windshield and backlight defrost, molten salt latent heat storage, metal hydride hydrogen storage and catalytic heater, and liquid fueled heater     

Bipolar nickel-metal hydride battery for hybrid vehicles

Hybrid electric vehicles are receiving increased interest as an approach to decrease vehicle pollution, dependence, and consumption of liquid petroleum and meet forthcoming Government vehicle emission standards. A number of schemes are under consideration (heat engine battery, fuel cell battery, peaking battery, inner-city battery, etc.). The success of any of the approaches will be dependent on battery capabilities, i.e., power, density, life, and cost. The nickel-metal hydride system appears to be the most promising of the candidate battery chemistries. Preliminary designs and analysis have been prepared and are presented for various configurations. Initial performance characterization tests are presented. It is concluded that a bipolar package arrangement for the Ni-MH chemistry appears most suited for the hybrid vehicle application considered     

Demonstration of a zinc bromine battery in an electric vehicle

The zinc bromine battery is a high energy density battery that utilizes low cost materials. The battery is of unique construction utilizing plastic storage tanks for the zinc bromide electrolyte and plastic bipolar electrode stacks. This paper briefly describes the zinc bromine battery technology and the experience gained in installing and operating an electric vehicle with this advanced system. The described electric vehicle (The “T-Star”) was tested in March 1993 on the Chrysler Proving Grounds in Phoenix, Arizona and it participated in the May 1993 American Tour de Sol capturing second place over all and first place in the student division     

Ultracapacitors + DC-DC converters in regenerative braking system

An ultracapacitor system for an electric vehicle has been implemented. The device allows higher accelerations and decelerations of the vehicle with minimal loss of energy and minimal degradation of the main battery pack. The system uses a DC-DC power converter, which is connected between the ultracapacitor and the main battery pack. The design has been optimized in weight and size, by using water-cooled heat sinks for the power converter, and an aluminum coil with air core for the smoothing inductance. The ratings of the ultracapacitor are: nominal voltage: 300 Vdc; nominal current: 200 Adc; capacitance: 20 Farads. The amount of energy stored allows us to have 40 kW of power during 20 seconds, which is enough to accelerate the vehicle without the help of the traction batteries. The vehicle uses a brushless DC motor with a nominal power of 32 kW and a peak power of 53 kW. A control system based on a Digital Signal Processor (DSP) manipulates all the aforementioned variables and controls the Pulse Width Modulation (PWM) switching pattern of the converter transistors. The car used for the implementation of this system is a Chevrolet LUV truck.     

太阳能飞机循环飞行的高度剖面能量策略

为满足设定的太阳能飞机多日连续飞行条件，依据飞行过程中当前时刻的飞行高度、光伏输出功率、动力电池组余量等系统状态参数，研究如何分配动力电池组充放电和电推进系统输入等功率。所用策略立足于实时功率平衡，充分利用正午前后的光伏峰值功率用于飞机爬升及充电，在午后下滑过程中利用全部光伏输出，以最大化利用光伏资源；在光伏有效输出不足时则以一定的维持功率下滑，使能量的综合损失最小。方法能够提高以预定夜间飞行高度连续多日续航的成功率，提升飞行高度、纬度、季节范围或搭载能力，或者拓展这几种飞行条件的组合域，优化太阳能飞机的适用性。     

基于轮毂电机的电动汽车再生制动研究

基于轮毂电机驱动的电动汽车的结构特点以及轮毂电机低转速、高转矩的特点,提出了轮毂电机再生制动方法。 为了恢复最大制动能量,在中等强度制动条件下通过轮内电机输出车辆减速的所有制动转矩。 由AMESim软件建立液压制动系统和轮毂电机驱动系统的车辆动力学模型。 通过NEDC循环和FTP75循环对车辆驾驶条件进行了仿真。仿真结果表明:采用轮内电机制动方式,制动能量回收率显著提高,电动车的能源效率提高30%以上。     

非车载充电机仿真建模

在阐述电动汽车非车载充电机的基本结构的基础上,根据非车载充电机的基本原理,针对不可控整流型非车载充电机,分析高频隔离式DC/DC变换器和充电机的控制电路,在Matlab-Simulink的平台上进行建模,对相关参数进行仿真,并对其注入电网和输出充电的电能进行评估。     

无人机增程式电推进系统双模糊能量管理策略仿真

为提高应用于无人机的增程式电推进系统能量利用效率,采用基于双层模糊控制的能量管理策略并使用遗传算法对控制参数进行优化,依据飞行动力学理论在仿真飞行工况中设置不同扰动,检验能量管理策略的抗飞行扰动效果。仿真结果表明:相比于基于多点逻辑门规则和比例积分微分PID（proportion integral differential）的能量管理策略,双模糊能量管理策略可使发动机运行平均燃油消耗率下降3.4%,整体燃油消耗量下降3.8%,电池使用量降低10.6%,发动机平均转速误差下降77.0%,面对突风扰动、复合扰动和连续紊流扰动时转速最大波动量分别降低71.4%、72.6%和46.7%。经过遗传算法优化后的双模糊能量管理策略相比优化前的控制参数,发动机平均转速误差下降6.6%,面对上述3种扰动时转速最大波动量分别降低12.8%、8.3%和39.4%。      

Development of a long cycle life sealed nickel-zinc battery forhigh energy-density applications

Nickel-zinc battery technology is being developed for commercial applications requiring high energy density and high power capability. Development cells have demonstrated the ability to deliver over 60 Watt-hours per kilogram at the one hour rate. Cycle life has been improved to more than 600 cycles at 80% depth of discharge by using a patented, reduced solubility zinc electrode and an improved sealed cell design. More than 8000 charge/discharge cycles at 10% depth-of-discharge have been completed. Large quantities of sealed prismatic cells have been manufactured, including a 140 cell, 220 V battery for a hybrid electric vehicle (HEV)     

GPS based prediction of the instantaneous impact point for sounding rockets

As part of the range safety operations during a sounding rocket launch, a real-time prediction of the instantaneous impact point (IIP) is performed to monitor the expected touch down point in case of a boost termination. Supplementary to traditional radar tracking, the IIP prediction is nowadays based on GPS navigation data, which offer an inherently higher accuracy and reduced data noise. To comply with the increased tracking performance, a consistent set of equations suitable for real-time computation of the approximate IIP is established. Aside from a consideration of gravitational forces, reference frame rotation and Earth curvature, the model can also account for drag during the ascent trajectory provided that a priori information on the ballistic properties of the launch vehicle is available. The algorithm is tested for a representative set of mission profiles and applied to GPS flight data of an Improved Orion rocket and a Maxus rocket launched at Esrange, Kiruna.     

Design and integration of a solar AMTEC power system with anadvanced global positioning satellite

A 1,200-W solar AMTEC (alkali metal thermal-to-electric conversion) power system concept was developed and integrated with an advanced global positioning system (GPS) satellite. The critical integration issues for the SAMTEC with the GPS subsystems included: (1) packaging within the Delta II launch vehicle envelope; (2) deployment and start-up operations for the SAMTEC; (3) SAMTEC operation during all mission phases; (4) satellite field of view restrictions with satellite operations; and (5) effect of the SAMTEC requirements on other satellite subsystems. The SAMTEC power system was compared with a conventional planar solar array/battery power system to assess the differences in system weight, size, and operations, Features of the design include the use of an advanced multitube, vapor anode AMTEC cell design with 24% conversion efficiency, and a direct solar insolation receiver design with integral LiF salt canisters for energy storage to generate power during the maximum solar eclipse cycle, The modular generator design consists of an array of multitube AMTEC cells arranged into a parallel/series electrical network with built-in cell redundancy. Our preliminary assessment indicates that the solar generator design is scaleable over a 500 to 2,500-W range. No battery power is required during the operational phase of the GPS mission. SAMTEC specific power levels greater than 5 We/kg and 160 We/m² are anticipated for a mission duration of 10 to 12 years in orbits with high natural radiation backgrounds     

航天飞机末端区域能量管理段制导技术概述

末端区域能量管理段主要是控制航天飞机的动能和势能．使航天飞机最终达到进场着陆段的初始要求，以保证其最终成功着陆。在最终制导系统引入一个能量基准剖面，通过调整飞行距离、动压或速度制动使航天飞机达到标准的能量状态。将末端区域能量管理段划分为四个飞行段，并对这四个飞行段的基本设计思想、制导技术及过程进行了研究。经过实际的航天飞机飞行验证．证明这种方案具有良好的制导效果。     

A microcontroller-based intelligent battery system

State-of-charge indication for a secondary battery is becoming increasingly important for battery-operated electronics. Consumers are demanding fast charging times, increased battery lifetime, and fuel gauge capabilities. All of these demands require that the state of charge within a battery be known. One of the simplest methods employed to determine state of charge is to monitor the voltage of the battery. However, this method alone is not a good indicator of battery energy, since both NiMH and NiCd batteries have voltage-versus-energy curves that are essentially flat. This paper presents a more effective method of determining the state of charge in secondary cell batteries. A NiMH battery is used as our test vehicle, since it is one of the more difficult batteries to determine state of charge. This method monitors the battery's temperature, voltage, and discharge/charge rate. A microcontroller then manipulates the information, using look-up tables to determine the state of charge. Also, by modifying the look-up tables, this technique can be employed in many other battery technologies and is not limited to NiMH     

小型电动无人机航程航时估算模型

小型电动无人机通常采用锂电池、无刷电机和螺旋桨组成能源动力系统,飞行过程中锂电池的实际工作电压发生变化,但飞机的总重量不变,其航程航时的估算方法与传统的燃油飞机有所不同。为了准确评估动力系统对飞机设计的影响,建立了以锂电池为动力的电动飞机推进系统模型,通过与实验数据比较,验证了各部分模型的准确性。利用该动力系统模型,对某款小型电动无人机进行了航程和航时估算,结果表明本文的建模方法准确有效,航程航时估算接近实验数据,可作为小型电动无人机设计的重要参考。