共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
为了教学而设计的电控发动机故障模拟试验台,基于单片机故障设置,可以反复模拟发动机在不同工况下各传感器、执行器、电控单元以及线路的各种故障.并在此试验台上模拟了发动机有关传感器和执行器的故障,如:空气流量传感器等,观察并记录了故障现象,定量分析了故障对发动机性能的影响. 相似文献
4.
5.
6.
7.
8.
作为喷油量和喷油正时均可灵活控制的时间式高压燃油喷射系统,电控组合泵的喷油正时直接关系到其所匹配的柴油机燃烧和排放性能,因此必须精确控制电控组合泵的喷油正时。本文详细分析了喷油正时的影响因素,对电控组合泵燃油喷射系统的喷射正时控制策略进行了设计,标定了起射和停喷延迟脉谱以及油量线性化脉谱。实机试验表明,应用此控制策略能有效保证柴油机的燃油喷射控制,实现了电控组合泵柴油机的平稳控制。 相似文献
9.
通过建立基于论域调整的自适应模糊PID控制算法对电控直列泵柴油机转速控制的位置环PID参数进行自整定.根据执行器的工作特性建立了执行器模型,与控制算法模型组成闭环进行仿真验证.通过与普通增量式PID控制算法的仿真结果进行比较,结果表明该控制算法在柴油机全工况范围内油量调节齿杆的控制效果优于普通增量式PID控制的效果. 相似文献
10.
11.
12.
《Journal of power sources》2005,140(1):72-80
Fuel cells are being considered as an important technology that can be used for various power applications. For portable electronic devices such as laptops, digital cameras, cell phone, etc., the direct methanol fuel cell (DMFC) is a very promising candidate as a power source. Compared with conventional batteries, DMFC can provide a higher power density with a long-lasting life and recharging which is almost instant. However, many issues related to the design, fabrication and operation of miniaturized DMFC power systems still remain unsolved. Fuel delivery is one of the key issues that will determine the performance of the DMFC. To maintain a desired performance, an efficient fuel delivery system is required to provide an adequate amount of fuel for consumption and remove carbon dioxide generated from fuel cell devices at the same time. In this paper, a novel fuel delivery system combined with a miniaturized DMFC is presented. The core component of this system is a piezoelectric valveless micropump that can convert the reciprocating movement of a diaphragm activated by a piezoelectric actuator into a pumping effect. Nozzle/diffuser elements are used to direct the flow from inlet to outlet. As for DMFC devices, the micropump system needs to meet some specific requirements: low energy consumption but a sufficient fuel flow rate. Based on theoretical analysis, the effect of piezoelectric materials properties, driving voltage, driving frequency, nozzle/diffuser dimension, and other factors on the performance of the whole fuel cell system will be discussed. As a result, a viable design of a micropump system for fuel delivery can be achieved and some simulation results will be presented as well. 相似文献
13.
为提高柴油机电磁式调速器的性能,揭示调速执行器动态特性参数的影响规律,采用数值模拟与试验相结合的方法,建立了动铁式电磁调速执行器的数值仿真模型,并通过试验验证了模型的精度,其最大误差为7%。通过数值模拟研究分析了电磁调速执行器的动态工作特性及脉冲宽度调制(pulse width modulation,PWM)频率、弹簧预紧力、弹簧刚度、负载大小、线圈匝数及导磁材料等参数对执行器动态特性的影响。结果表明:初始阶段适宜采用大占空比或满占空比来加快执行器的动态输出速度,以较小的占空比来维持满行程的输出以提高执行器的动态回位速度;提升执行器的位移-力的水平特性有助于提高执行器行程输出的线性度;此外,发现PWM频率、弹簧预紧力、弹簧刚度、负载大小、线圈匝数及导磁材料等参数对执行器动态特性均具有重要影响。 相似文献
14.
Since portable wireless power charger devices have grown rapidly in the market, this device has potential to become standard power charger for portable electronic devices. It offers enhanced consumer convenience and experience. This article presents an innovative portable wireless power charger that is more environmental-friendly because it uses a hydrogen gas fuel cell as the power source. Compared with fossil energy, the fuel cell is clean and renewable, which does not contribute a negative impact on the environment. A wireless power transmission (WPT) system was developed based on the electromagnetic induction technique in order to propagate electromagnetic energy from the transmitter to the receiver with operating frequency at 110 kHz. A four-cell proton exchange membrane fuel cell (PEMFC) planar module with open type at cathode side was applied to provide 4.11 W with its low-voltage and high-current features. A single-cell PEMFC produces output voltage ranging from 0.6 to 0.7 V and configures in serial to form a four-cell PEMFC planar module. Two DC-DC boost converter module in a parallel configuration was used to convert to a suitable voltage and current to the WPT module. The experimental validation shows that the developed system provides power around 1.6 W to the device battery under recharging with power efficiency delivery up to 70%. The charging experiment reveals the device battery capacity under recharging (cell phone) increases 1% in 3.3 minutes and it consumes the hydrogen at around 1.2 L. 相似文献
15.
16.
根据变齿距电磁作动器的几何结构和传热特点,建立其集中参数热模型。对加工好的样机温度进行了试验测量,并将集中参数热模型的计算结果与试验数据进行了对比,结果表明,在不同线圈电压下,作动器线圈和外壳温度的最大相对误差仅为8.40%和9.22%,证明了所建立模型的有效性。利用所建立的集中参数热模型,研究了作动器温升对各个热阻的敏感性,结果表明,作动器温升对外壳与环境之间的散热热阻最为敏感,当其增加20%时,线圈温度和外壳温度将分别增加6.10%和8.40%,而其他热阻对作动器的线圈和外壳温度的影响都非常小。最后,对变齿距电磁作动器的冷却方式进行了探讨,高电密的情况下,在外壳设计散热肋片是提高冷却效果的实用方式。 相似文献
17.
18.
19.
20.
设计了采用新型高效电磁作动器的发动机振动主动控制系统。简要介绍了发动机振动控制系统,将电磁作动器布置到该系统中,建立了单自由度发动机振动主动控制系统数学模型。针对发动机二阶惯性力引起的垂直振动,采用PID控制策略开展主动控制仿真研究。以正弦信号代替发动机的二阶惯性力作为激励源,通过Simulink仿真工具进行了仿真分析。仿真分析结果表明,采用PID控制策略后的发动机在较宽的频率范围内垂直振动衰减明显,该发动机振动控制系统是行之有效的。 相似文献