船舶柴电混合动力系统在电力助推模式下的性能仿真研究

应用AMESim软件对船舶柴电混合动力系统建模并进行试验验证。试验验证表明:所建立的模型稳态误差≤5%,满足精度要求。采用所建立的模型仿真分析了Booster模式下系统在不同工况下的匹配特性;并研究了柴油机与轴带电机稳定运行的控制策略。     

油电混合动力无人机能量管理策略的对比仿真研究

针对固定飞行任务的油电混合动力无人机,降低混合动力系统瞬时燃油消耗率,增加续航里程的工作需求,设计了可以应用于固定飞行任务油电混合动力无人机的不同能量管理策略,主要包括固定规则、模糊逻辑和动态规划算法的能量管理策略。根据油电混合动力无人机动力源特性,通过理论和试验建模相结合的方法,在MATLAB中建立油电混合动力系统的数学模型、飞行任务相对应的仿真工况及不同能量管理策略的控制程序。重点对比了基于优化的动态规划算法能量管理策略相比固定规则和模糊逻辑策略在燃油经济性和运行稳定性方面的表现。仿真结果表明：动态规划算法策略的累积燃油消耗量相比固定规则、模糊逻辑策略分别下降了4.6%和6.5%,平均瞬时燃油消耗率分别下降了5.1%和5.9%;在应对外部突风扰动时,动态规划能量管理策略的航空发动机最大转速波动相比固定规则的能量管理策略下降了59.7%,应对随机紊流扰动时,动态规划策略航空发动机的最大转速波动相比固定规则和模糊逻辑分别下降了33.9%、25.6%。动态算法作为一种全局最优算法,应用在固定飞行任务的油电混合动力无人机能量管理策略中时,可在提高混合动力系统燃油经济性的同时保证系统运行的稳定性。     

复合翼无人机混合动力系统能量管理策略设计

以某最大起飞质量为25 kg的复合翼无人机混合动力系统为研究对象,基于MATLAB/Simulink平台搭建动力系统关键部件数学模型、集成复合翼无人机混合动力系统级仿真模型,依据复合翼无人机在多点悬停作业场景下的飞行任务要求,设计相应的飞行任务剖面与基于等效燃油最小消耗的能量管理策略,进行仿真试验验证。结果表明：基于等效燃油最小消耗能量管理策略的无人机动力系统的油门跟随性良好,满足无人机实际运行需要;动力电池荷电状态可以维持在设定值附近,相对误差小于1.5%;相比基于规则的能量管理策略,基于等效燃油最小消耗管理策略的混合动力系统无人机在点对点飞行和多点悬停作业2种飞行工况下的燃油消耗分别下降了6.07%、5.49%。     

轻微型无人机活塞发动机测控与建模方法

针对活塞发动机应用到油电混合动力无人机（unmanned aerial vehicle, UAV）系统中燃油经济性的不确定性,基于Arduino平台开发了一套轻微型无人机活塞发动机测控试验台,给出了试验台总体设计方案,介绍了测控系统的总体架构和功能。基于多元线性回归数据处理方法,对测控试验台采集到的数据进行处理,在MATLAB中将发动机等燃油消耗率曲线和等功率曲线拟合成三维模型,获得了活塞发动机万有特性曲线,在此基础上建立了活塞发动机稳态模型。此外,采用实验建模法在Simulink软件中建立了轻微型无人机活塞发动机动态模型,通过模型数据与实物数据进行对比,验证了建模方法的有效性。结果表明,测控试验台具有较高的稳定性与良好的精度,所建立的活塞发动机数值模型能够较好地表征发动机稳态与动态响应过程,该建模方法能够寻找到轻微型无人机活塞发动机工作高效区间。     

某大型舰船主汽轮机的建模与动态仿真

以某大型舰船主汽轮机为研究对象,充分考虑了舰船主汽轮机的结构特性,针对舰船主汽轮机特性建立集总参数动态仿真数学模型,在SimuWorks热力系统平台上,搭建相应仿真模型。对主汽轮机进行稳态工况和加速、减速及倒车过程的全工况动态仿真。仿真结果表明,模型具有较高精度,高速工况下偏差在2%以内,动态趋势合理,能准确反映出部件实际工作状态。该仿真模型可以应用于舰船动力系统的仿真。     

某渔业资源调查船柴电混合动力系统设计及应用

基于船舶动力系统设计平台,根据某渔业资源调查船运行工况,从柴电混合动力系统运行模式分析、设备选型分析、推进轴系回转振动分析等方面着手,开展柴电混合动力系统设计.设计的柴电混合动力系统与传统柴油机动力系统相比,装机功率降低了 17.9％,油耗降低了 6.5％.经实船应用,各项性能指标均满足技术要求.     

用于控制的发动机转矩估计方法研究

有一定精度和实时性的发动机动态转矩估计模型,对机电混合电动汽车动力及传动系统控制有重要意义.对发动机动态特性的影响因素进行了分析;分析了平均值模型的优缺点,针对混合动力控制和建模仿真的需要,对模型进行了有效的简化,大大提高了模型的实用性;分析了混合动力中发动机的特定动态工况,建立了特定动态工况下的发动机神经网络模型;基于发动机稳态和动态试验数据,对平均值模型和神经网络模型进行了实证研究.结果表明,基于神经网络的简化平均值模型适用于发动机稳态工况和节气门开度变化率不大的动态工况;神经网络模型适用于发动机稳态工况和特定的动态工况.     

基于支持向量机的柴电混合动力故障诊断研究

对柴电混合动力系统级故障诊断进行了研究,利用仿真软件搭建了实时整车模型,并构建了基于支持向量机的柴电混合动力系统的诊断框架.采用一对一方法构建多分类器,故障识别准确率达到98％.构建了柴电混合动力系统故障诊断实时仿真平台,进行了基于支持向量机的柴电混合动力系统故障诊断实时仿真,验证了实时环境下基于支持向量机诊断算法能有...     

基于AMESim的柴油发电机组建模与仿真

利用系统建模与仿真软件AMESim建立了某柴油发电机组的仿真模型,进行了稳态过程和动态过程的仿真,并与试验数据对比,证明所建立的仿真模型具有较高的仿真精度,可以用于研究柴油发电机组在动态工况下的运行特性。     

柴电混合动力系统电力推进模式下离合器柔性接排启动轴系过程仿真研究

以某公务船柴电混合动力系统为研究对象,利用AMESim软件建立动力系统仿真模型,开展电力推进模式中轴系接排启动过程的仿真研究。仿真分析了采用柔性接排技术后,轴带电机在齿轮箱离合器高速接排启动轴系过程中所受冲击的大小变化,并和试验数据进行比较。结果表明:柔性接排可有效降低接排过程中轴带电机所受的冲击,保证系统可靠运行;仿真模型动态精度大于90%,仿真模型有效。     

Research on ADHDP energy management strategy for fuel cell hybrid power system

Fuel cell hybrid power system is a prospective power source for electrical vehicles. To reduce hydrogen consumption and enhance dynamic performance of the system, Action Dependent Heuristic Dynamic Programming (ADHDP) energy management strategy for the fuel cell hybrid power system was proposed. Firstly, topology of the system was analyzed and mathematical model was established through mechanism analysis. Secondly, framework of the ADHDP algorithm was presented, and it was followed by training algorithm for evaluating network and executing network of ADHDP based on Back Propagation (BP) algorithm. Finally, hardware-in-the-loop (HIL) simulation of the fuel cell hybrid power system was carried out to demonstrate the proposed ADHDP algorithm under real operating conditions. The results show that evaluating network and executing network of ADHDP have good convergence performance under different operating conditions. Compared with the other algorithms, the proposed ADHDP energy management strategy has better fuel economy and dynamic performance.     

Architecture design and performance analysis of a hybrid hydrogen fuel cell system for unmanned aerial vehicle

The flight endurance of UAV systems is an important issue that restricts the operational capabilities. Thus, different energy systems and alternative onboard energy generation systems have been tested for the UAVs. Within these systems, fuel cells provide high energy density that can increase flight endurance greatly. In this study, a PEM fuel cell – Li-Po battery hybrid system has been developed by evaluating three architecture models. In the guide of the experimental power demand data of a fixed-wing UAV, modeling and testing procedures were performed. Battery voltage and fuel cell current variations observed during the ground tests were evaluated. It has been observed that approximately 160–170 W of the 250 W power is met by the fuel cell since no preconditioning has been applied and the temperature values at which the fuel cell exhibits its optimum performance. In the case where the fuel cell could provide 7.8 An under conditions where the humidification effects were not included in the model, the required current was over 7.8 A between approximately 400-1200 s. The fuel cell and battery behavior in response to the sudden power changes and to the uncertainties corresponding to the changes in the motor power during the flight are also detailed.     

Design and development of a fuel cell-powered small unmanned aircraft

The design, construction, and flight test of a fuel cell-powered small unmanned aircraft are described. A fuel cell system featuring a polymer electrolyte membrane fuel cell combined with a hydrogen generator, which serves as a new power source alternative to the existing batteries, is proposed. The hydrogen generator uses a catalytic hydrolysis reaction to extract hydrogen from an alkaline solution of sodium borohydride, and constructed with a reactor, pump, separator, and fuel cartridge. Considering the performance characteristics of the fuel cell, the hybrid power management of a fuel cell and a battery was contrived. The fuel cell stack, hydrogen generator, and power management system were evaluated at the various load conditions. A high efficiency unmanned aircraft was designed and fabricated to validate the possibility of the proposed fuel cell system, and a small flight control system was developed for a high endurance test flight. Wind-tunnel tests were conducted before the flight tests under actual flight conditions. The possibility for the utilization of a fuel cell in a small aircraft was validated through the fuel cell powered flight test. The fuel cell aircraft flew for 2 h without incidents in the fuel cell system.     

基于GaN的准方波Boost变换器拓扑分析

基于实际太阳能无人机的应用背景,对其核心功率变换部分展开深入研究。通过在传统同步整流型Boost变换器基础上增加少量无源元件,利用电感电流的连续性,构造功率开关输出电容放电环节,在保证主功率电感电流纹波较小的情况下实现功率开关的零电压开通,克服传统同步整流型Boost变换器为实现软开关而工作于准方波模式下,电感电流纹波较大的问题,从而有助于延长无人机蓄电池组的使用寿命。从该拓扑的模态分析出发,对功率开关的零电压开通实现过程进行详细分析。此外,对变换器进行参数设计,总结整个变换器的主要损耗计算方法。最后,利用GaN功率开关器件,搭建一台额定功率为500 W的实验样机,并与相同工况下的同步整流型Boost变换器进行对比。实验结果与理论分析基本一致,峰值效率达到96%。验证了理论分析的准确性以及该拓扑的实际可行性。     

有轨电车用燃料电池系统效率研究

文章基于100 kW燃料电池试验平台,对燃料电池系统的辅机功耗及系统效率进行了研究。通过启动、稳态和加减载3个试验,研究了不同工况下辅机功耗以及系统效率。研究结果表明:最小功率启动时,燃料电池的功率不足以维持辅机工作,需要外部电源提供差额功率;在散热良好条件下,额定功率时压缩机、散热器、循环水泵和氢气回流泵的功耗分别占电堆功率的12.3%,1.10%,0.70%,1.06%;用电效率、发电效率和系统效率分别为85.0%,54.1%,46.0%;随着电堆功率的增长,发电效率降低,用电效率和系统效率存在最优值。     

Effect of flight level to maximum power utilization for PEMFC/supercapacitor hybrid uav with switched reluctance motor thruster

In this study, the performance of a fixed-wing PEMFC/SC hybrid UAV with an SRM thruster is investigated by different flight levels. Flight levels negatively affect the PEMFC due to changing ambient conditions such as air temperature and pressure. Hence, the international standard atmosphere (ISA) model for PEMFC voltage-current-power ratings is derived with 100 m intervals for 0–7500 m. The demanded electrical power by UAV increases at high altitudes due to the compressor used for air pressurization of PEMFC. Therefore, a maximum power point tracking (MPPT) model of PEMFC should be utilized in case of overshooting the maximum power level that can be provided. While the main power source of the UAV is PEMFC, the auxiliary power source is SC. The SC is preferred for DC bus voltage stabilization, avoiding maximum power point overshoot, and preventing high instantaneous current that shortens the lifespan of PEMFC. The proposed UAV model is verified at MATLAB/Simulink and the results prove that the system is satisfying.     

基于永磁同步发电机的直驱风电双脉宽调制变流器的研制

阐述了永磁直驱风电系统背靠背双脉宽调制(PWM)全功率变流器的电路结构和控制原理,利用Matlab软件建立了该系统的仿真模型,对其稳态和动态性能进行了分析.并构建了永磁直驱风电试验平台和双PWM变流器系统.结果表明:采用双PWM变流器作为永磁直驱风电系统的变流器,可以实现对永磁同步发电机(PMSG)的优良控制,并向电网输送优质的电能.     

单相光伏并网逆变器控制策略的比较研究

采用单相两级式光伏并网拓扑结构,针对传统双闭环控制策略,在光伏电池输人功率发生骤变时,响应滞后,系统稳定性较差的缺点,采用带有输入功率前馈的双闭环控制策略,并对其进行详细地分析。通过上述的分析,基于MATLAB平台,分别就两种策略搭建了光伏并网系统的仿真模型。仿真结果表明,当输入功率发生突变时,相对于传统双闭环控制策略,带有功率前馈的双闭环控制策略,其并网电流能够更快地达到新的稳定,同时降低了直流母线电压在该过程中的波动,具有更优越的动态性能。     

Fuel cell system with sodium borohydride as hydrogen source for unmanned aerial vehicles

In this study, we design and fabricate a fuel cell system for application as a power source in unmanned aerial vehicles (UAVs). The fuel cell system consists of a fuel cell stack, hydrogen generator, and hybrid power management system. PEMFC stack with an output power of 100 W is prepared and tested to decide the efficient operating conditions; the stack must be operated in the dead-end mode with purge in order to ensure prolonged stack performance. A hydrogen generator is fabricated to supply gaseous hydrogen to the stack. Sodium borohydride (NaBH₄) is used as the hydrogen source in the present study. Co/Al₂O₃ catalyst is prepared for the hydrolysis of the alkaline NaBH₄ solution at room temperature. The fabricated Co catalyst is comparable to the Ru catalyst. The UAV consumes more power in the takeoff mode than in the cruising mode. A hybrid power management system using an auxiliary battery is developed and evaluated for efficient energy management. Hybrid power from both the fuel cell and battery powers takeoff and turning flight operations, while the fuel cell supplies steady power during the cruising flight. The capabilities of the fuel-cell UAVs for long endurance flights are validated by successful flight tests.