自走式无人驾驶植保机用发动机转速控制系统设计

针对自走式无人驾驶车辆在起步、换挡过程中产生强烈的顿挫感,甚至导致车辆突发性前窜的现象,开发基于扭矩需求的发动机转速控制系统。该系统能够根据发动机扭矩需求的变化,调整比例积分微分(proportion integral differential,PID)控制参数,实现对节气门开度的控制,达到调整转速的目的。研究车辆起步、换挡过程中发动机扭矩的变化规律,确定发动机转速控制目标;运用神经元自适应PID算法,对发动机转速进行闭环控制,解决传统PID最佳参数设置问题;选用永磁直流电动机对节气门进行控制,解决传统油门电机精准性问题。试验结果表明,该控制系统能够根据扭矩变化调整发动机转速,并能在短时间内使发动机运行达到稳定状态,对发动机转速控制具有较好的动态特性。     

改进摩托车发动机进气性能的研究

针对摩托车发动机结构紧凑、转速高的特点，在保证配气机构动力特性的基础上，对进气凸轮进行了改进设计；并在结构允许的前提下，对发动机进气系统也进行了相应的改进设计，使发动机的进气性能得到明显改善。试验表明，发动机扭矩最大提高9．5％，最大功率提高5．4％，发动机的燃油耗也有一定程度的改善。     

发动机热力过程仿真与进气系统优化

本文将通过Lotus Engine Simulation软件模拟计算发动机的热力过程,并对发动机进行优化设计。通过调整相关变量以提高功率和扭矩值,使其峰值向低转速方向移动。综合优化后,提高了发动机的最大转矩和最大功率,提升中低转速扭矩的同时,降低了燃油消耗率。     

湖南仪器仪表总厂动力测试仪器厂产品介绍

<正> 1 KW-1型电涡流测功控制仪能同各种电涡流测功机配套使用,用于发动机台架试验,实现发动机工况的自动控制。可数显和模拟显示扭矩、转速以及设定值。具有对测功器、恒扭矩、恒转速和恒电流进行控制的机能。具有对发动机恒扭矩、恒转速和油门位置进行控制的机能。具有外部控制接口,可配上位计算机,便于组成全自动程控系统。 2 GW系列电涡流测功机规格表 3 DNI内燃机测控系统数显扭矩、转速、功率、小时耗油量、油耗率、环境温度、排温、水温、油温和油压,并具有各参数的报警指示和打印输出。自动程序控制扭     

电控汽油机进气管长度连续可变系统

通过分析、设计、计算，研制了一种进气管长度连续可变系统，使得赛车发动机在不同的工作转速均有较高的扭矩。     

发动机可变长度进气歧管系统的优化设计研究

以发动机进气歧管长度、直径和不同长度的进气歧管切换的发动机转速等为设计变量,以发动机进气系统的充气效率、低速扭矩及其转速、最大扭矩及其转速和最大功率等为优化目标,应用发动机热力学和性能分析商用软件GT-POWER进行多目标优化仿真计算,确定优化设计方案;然后制作快速成型样件,通过试验验证计算结果,从而完成发动机可变进气歧管的优化设计。     

电控汤油机进气管长度连续可变系统

通过分析，设计，计算，研制了了一种进气管长度连续可变系统，使得赛车发动机在不同的工作转速均有较高的扭矩。     

汽油机进气歧管副谐振腔设计开发研究

对某一1.5 L排量4缸汽油进气歧管进行设计改进,增加副谐振腔设计改善扭矩凹坑。试验结果表明,赫姆霍兹谐振腔能有效解决扭矩凹坑,进气门开启持续期和空滤管对扭矩凹坑对应的发动机转速影响明显,进气门的正时相位角不会影响扭矩凹坑对应的发动机转速点;赫姆霍兹谐振腔的应用需要与空滤系统和凸轮型线设计一同考虑,才能发挥所需要的效果。     

混合动力汽车发动机转速控制策略研究

为消除混合动力汽车发动机运转过程中的转速振荡，利用发动机转速-节气门开度-扭矩对应关系，采用PID控制器调整发动机转速波动。同时，对低负荷发电工况、换档过程发动机转速调整工况下混合动力汽车发动机转速控制策略进行了研究。试验表明上述工况中没有较大振荡产生，发动机转速响应迅速，能够满足整车设计的需要，并为同类研究提供参考。     

汽车发动机瞬时转速信号波动规律分析

１　瞬时转速波动规律的理论分析　　发动机的瞬时转速信号是实现发动机的诊断和闭环反馈控制的一个重要途径。了解瞬时转速在不同工况下的波动规律,有助于建立各缸工作状态的检测算法。由于瞬时转速波动是发动机总扭矩波动导致的结果,因此通过分析发动机的总扭矩波动可获得瞬时转速波动在不同转速和不同负荷时的波动特征。若把各缸气体压力产生的扭矩之和称为气体压力扭矩ｔｇ,各缸往复惯性力产生的扭矩之和称为惯性力扭矩ｔｊ,则发动机的总扭矩ｔｓ即为ｔｇ与ｔｊ之和。本文利用实测缸内压力对ＹＣ６１０８发动机在不同转速和负荷时的…     

Areal evolution of PV systems

If a large amount of the future penetration of PV systems is imaged, it is likely that they densely concentrate in a certain area. It may not be a simple aggregation of individually optimized system, but a different system image may result by the total optimization of an area. The author frames this new question as the problem of “Areal Evolution” or “PV-AREA”. The following two cases are dealt with and their concrete concepts are given: (1) PV systems for community, (2) global-scale utilization of PV systems.     

HS-510型发动机的改进设计

本文介绍了HS—510型发动机的改进过程。通过改进使其功率提高和燃油经济性改善。同时也说明一个产品只有不断地改进和完善，才能满足社会进发展的需要。     

1台1 025 t/h液态排渣锅炉的设计和运行特点

介绍了1台1025t/h液态排渣锅炉汽水系统、燃烧系统和控制系统等设计和运行的若干特点,对国内同类型锅炉的设计和运行具有指导意义。     

计算机辅助计量管理系统

计算机辅助管理系统研制开发的必要性以及国内外概况,并对系统开发的最终目标、功能及其意义进行了阐述.     

光伏系统蓄电池组不均衡性的故障分析及排除

蓄电池组是光伏系统的重要设备,其故障往往导致光伏系统不能正常运行。光伏系统蓄电池组的故障多数因其不均衡所致。文章分析了蓄电池组因不均衡性导致的故障,提出了故障预防措施和故障排除方法。     

Operation strategy of residential centralized photovoltaic system in remote areas

Photovoltaic (PV) systems have found fairly wide application in remote isolated area. However, each individual PV system usually supplies energy only to one consumer. In such a case we have several consumers that each one of them uses a stand-alone PV system. This situation would expose such stand-alone systems to transient excessive loads larger than the power generated by the PVs, and then the battery is bound to discharge even during the day. For overcoming this problem, we suggest an autonomous centralized PV system, comprising one battery bank and plural subsystems connected to each other. From solar radiation data and load profiles, the performance of the PV centralized system is simulated by using a time step scheme. The advantages of this system are found to be the large charging rate of power, high efficiency, and low cost compared with conventional individual PV systems and hybrid systems. In addition, the economic study shows that the life cycle cost and the price of kilowatt hour generated in the centralized system is lower than that for the individual systems.     

板坯连铸机冷却水系统的完善与应用

针对北方某厂板坯连铸机生产状况，对其软水冷却系统、设备净环水冷却系统和二次喷淋浊环水冷却系统进行了研究分析，提出了冷却水系统的完善方案，解决了连铸水系统的稳定性，避免了频繁开停泵对连铸水系统高压电机的冲击及冬季长时间停机或检修造成设备和管道系统内部滞水而冻结，提高了事故处理的灵活性和环境适应性。     

Sustainable electricity generation for rural and peri-urban populations of sub-Saharan Africa: The “flexy-energy” concept

Access to energy is known as a key issue for poverty reduction. Electrification rate of sub-Saharan countries is one of the lowest among the developing countries. However, this part of the world has natural energy resources that could help raising its access to energy, then its economic development. An original “flexy-energy” concept of hybrid solar PV/diesel/biofuel power plant, without battery storage, is performed in this paper. This concept is developed in order to not only make access to energy possible for rural and peri-urban populations in Africa (by reducing the electricity generation cost) but also to make the electricity production sustainable in these areas. For landlocked countries like Burkina Faso, this concept could help them reducing their electricity bill (then their fuel consumption) and accelerate their rural and peri-urban electrification coverage.     

Optimal sizing of stand-alone hybrid systems based on PV/WT/FC by using several methodologies

This paper presents a comparative study of four sizing methods for a stand-alone hybrid generation system integrating renewable energies (photovoltaic panels and wind turbine) and backup and storage system based on battery and hydrogen (fuel cell, electrolyzer and hydrogen storage tank). Two of them perform a technical sizing. In one case, the sizing is based on basic equations, and in the other case, an optimal technical sizing is achieved by using Simulink Design Optimization. The other two methods perform an optimal techno-economical sizing by using the hybrid system optimization software HOMER and HOGA, respectively. These methods have been applied to design a stand-alone hybrid system which supplies the load energy demand during a year. A MATLAB-Simulink model of the hybrid system has been used to simulate the performance of hybrid system designed by each method for the stand-alone application under study in this work. The results are reported and discussed in the paper.     

热力系统控制可容错性分析与应用研究

根据系统可控性和可观测性理论，通过对控制系统中元(部)件冗余性、冗余度的分析，研究故障系统可容错的条件，对稳压器压力控制系统进行可容错性定量分析；通过分析控制系统的部件对系统的静态性能、动态性能的影响程度，容错控制系统的部件重要度分析，确定引起控制系统故障的关键部件。