Real time power management strategy for fuel cell hybrid electric bus based on Lyapunov stability theorem

The fuel cell/battery durability and hybrid system stability are major considerations for the power management of fuel cell hybrid electric bus (FCHEB) operating on complicated driving conditions. In this paper, a real time nonlinear adaptive control (NAC) with stability analyze is formulated for power management of FCHEB. Firstly, the mathematical model of hybrid power system is analyzed, which is established for control-oriented design. Furthermore, the NAC-based strategy with quadratic Lyapunov function is set up to guarantee the stability of closed-loop power system, and the power split between fuel cell and battery is controlled with the durability consideration. Finally, two real-time power management strategies, state machine control (SMC) and fuzzy logic control (FLC), are implemented to evaluate the performance of NAC-based strategy, and the simulation results suggest that the guaranteed stability of NAC-based strategy can efficiently prolong fuel cell/battery lifespan and provide better fuel consumption economy for FCHEB.     

Three-phase four-wire shunt active power filter based on the SOGI filter and Lyapunov function for DC bus control

The three-phase four-wire shunt active power filter (SAPF) was developed to suppress the harmonic currents generated by nonlinear loads, and for the compensation of unbalanced nonlinear load currents, reactive power, and the harmonic neutral current. In this work, we consider instantaneous reactive power theory (PQ theory) for reference current identification based on the following two algorithms: the classic low-pass filter (LPF) and the second-order generalized integrator (SOGI) filter. Furthermore, since an important process in SAPF control is the regulation of the DC bus voltage at the capacitor, a new controller based on the Lyapunov function is also proposed. A complete simulation of the resultant active filtering system confirms its validity, which uses the SOGI filter to extract the reference currents from the distorted line currents, compared with the traditional PQ theory based on LPF. In addition, the simulation performed also demonstrates the superiority of the proposed approach, for DC bus voltage control based on the Lyapunov function, compared with the traditional proportional-integral (PI) controller. Both novel approaches contribute towards an improvement in the overall performance of the system, which consists of a small rise and settling time, a very low or nonexistent overshoot, and the minimization of the total harmonic distortion (THD).     

CNG-电混动公交车道路行驶工况与排放特性研究

CNG-电公交车以天然气作为发动机燃料,辅以电机共同驱动的混合动力车辆,车辆行驶速度低、启动频繁等特性,发动机实际运行工况与型式检验工况具有较大差异。为研究其实际行驶工况与排放特性,选取4辆国V排放标准的CNG-电混合动力公交车,往返于市区与城郊,使用PEMS(portable emission measurement system)实时收集车辆行驶及NO_X排放数据。结果表明,发动机运行工况集中于中低功率段,与型式检验工况差异较大,污染物排放集中于发动机切入车辆传动系统的临界车速附近。     

基于CAN总线的多通道开度阀控制系统的设计

针对现有电动阀门控制系统可嵌入性差的问题，设计了一种基于CAN总线的网络化、多通道、开度型阀门嵌入式控制系统。其中，上位机主要用于下达各阀门开度等控制指令并同时监测其工作状态，而下位机采用双MCU架构，主MCU用于控制各阀门的开度大小，从MCU负责采集开度反馈电流以实现闭环控制。下位机采用了模糊PID算法进行控制参数的动态整定，可满足阀门在不同工况下的控制精度要求，并通过OLED屏显示各通道阀门的实际开度值。实验表明,该控制系统运行稳定，能实现对多通道开度阀的精准控制，控制精度在0.6%以内，并支持远程上位机控制和现地控制等多种工作模式。     

一种二线制无极性数字称重传感器

现有的数字传感器至少由2根数据线和2根电源线共4根线组成,每根线均有明确的分工和极性,不能接错和短路,否则易损坏设备,需专业人员才能安装和维护;数据传输加密方式有限,易破解。利用本公司研发的"智能终端整机供电用二线制数据/电源共线传输装置及方法",将数字传感器的连线减至2根,且无极性、可短路,简化了系统的连接,提高系统的可靠性,使安装和维护变得极为简便。数据传输采用特殊的加密方式,极难破解。     

单片机应用系统综合实验装置的设计

单片机原理与应用作为电子技术类学科中的必修课程具有很强实践性,要求学生掌握实际应用能力,为此研制了基于单片机系统通信为基础的实验板,依据单片机应用系统特点,可完成SPI、I^2C、UART串行通信以及并行总线方式通信。实验板有利于学生更好地了解和掌握单片机应用系统设计的方法,有利于学生进行自主设计和内容拓展。做到培养学生的学习能力、提高学生的学习兴趣、发挥学生的创造性。     

基于软PLC的电气控制器设计

针对以传统PLC为核心设计的控制器存在的电路和控制方式复杂的问题,选用具有可靠性高、抗干扰能力强、易在线修改、易调试操作,具有CAN通信模块的新型软PLC作为电气控制器的控制核心,实现对外部信号的采集、转换、控制,达到了对系统精确控制的目的。实践表明,以软PLC为核心的电气控制器的成功应用,不仅提高了电气控制系统的稳定性和可靠性,且为其他控制系统提供了技术支持和应用依据。     

粘合树脂PN760在全钢载重子午线轮胎钢丝胶中的应用

研究粘合树脂PN760在全钢载重子午线轮胎钢丝胶中的应用。结果表明:在钢丝胶中以粘合树脂PN760替代间苯二酚,胶料的门尼粘度增大,门尼焦烧时间缩短,t90延长;硫化胶的物理性能变化不大,粘合性能提高;成品轮胎的耐久性能提高,可减少环境污染。     

0.25+6+12×0.225HT钢丝帘线在11.00R20全钢载重子午线轮胎胎体中的应用

以0.25+6+12×0.225HT钢丝帘线替代3+9+15×0.22+0.15钢丝帘线应用于11.00R20 18PR全钢载重子午线轮胎胎体。试验结果表明,以0.25+6+12×0.225HT钢丝帘线替代3+9+15×0.22+0.15钢丝帘线用于11.00R20 18PR全钢载重子午线轮胎胎体后,成品轮胎的外缘尺寸变化不大,强度性能和耐久性能提高,且轮胎原材料成本降低。     

3+9+15×0.225HT钢丝帘线在全钢载重子午线轮胎胎体和带束层中的应用

以3+9+15×0.225HT钢丝帘线替代3+9+15×0.22+1NT钢丝帘线用于12.00R20 18PR全钢载重子午线轮胎胎体和带束层。结果表明,以3+9+15×0.225HT钢丝帘线替代3+9+15×0.22+1NT钢丝帘线用于12.00R20 18PR全钢载重子午线轮胎胎体和带束层,成品轮胎的外缘尺寸基本不变,轮胎强度性能、耐久性能和速度性能以及胎圈耐久性能均有较大提高,在不增加胎体和带束层质量和成本的情况下,胎体和带束层安全倍数大幅提高,从而提高了轮胎的使用安全性能和负荷能力。