Sensorless switched reluctance starter/generator performance

This article compares the performance of a high speed switched reluctance starter/generator (SR S/G) system when operating with a resolver to that when operating resolverless, or sensorless. The SR SIG system is a 270 Vdc system that performs two primary functions. The first is to start a gas turbine engine using an available source of 270 Vdc power. The second is to extract power from the gas turbine engine to generate 270 Vdc, with power quality defined by MIL-STD-704E. In addition to the control requirements for the different modes of operation, the system includes extensive protection functions to ensure that proper action is taken in the event that certain parameters of the system exceed operational limits. The system must be capable of the same control and protection operation, when running sensorless, as it is when operating with the resolver. Extensive system testing has been carried out on the SR SIG system using resolver-based rotor position sensing. For future applications, however, there is the desire to eliminate the resolver and operate in a resolverless, or sensorless, mode. This article compares the performance of the system for both start and generate modes of operation for tests performed on a high-speed dynamometer     

高速工况下车载综合电力系统失稳预测

针对车载综合电力系统因离网运行、发动机动态响应慢以及工况复杂从而易失稳的问题,开展了系统失稳预测研究.通过建立各微源、负载变换器的小信号模型,得到各微源输出阻抗与负载输入阻抗.基于改进的阻抗比判据提出了车载综合电力系统小信号失稳判据.利用波特图从发动机转速、车速以及驱动电机转矩3个方面进行系统失稳预测分析.最后通过硬件...     

Thermo-economic multi-objective optimization for a solar-dish Brayton system using NSGA-II and decision making

A 100 kW regenerative Brayton heat engine driven by the hybrid of fossil fuel and solar energy was considered for optimization based on multiple criteria. A thermodynamic model of such hybrid system was developed so that the power output, thermal efficiency and dimensionless thermo-economic performance with the imperfect performance of parabolic dish solar collector, the external irreversibility of Brayton heat engine and conductive thermal bridging loss could be obtained. Evolutionary algorithm based on NSGA-II (Elitist Non-dominated Sorting Genetic Algorithm) was employed to optimize triple-objective and dual-objective functions, where the temperatures of hot reservoir, cold reservoir and working fluid, the effectiveness of hot-side heat exchanger, cold-side heat exchanger and regenerator were considered as design variables. Using decision makings, including Shannon Entropy, LINMAP and TOPSIS methods, the final optimal solutions were selected from Pareto frontier obtained by NSGA-II. The results show that there exists an appropriate working fluid temperature to cause optimal solution under each given condition. The comparisons of triple-objective and dual-objective optimization with single-objective optimization indicate that multi-objective optimization can yield the more suitable results due to the lower deviation index from the ideal solution. In the analysis of triple-objective optimization, an expected result is obtained that the optimal values of the power out, efficiency and dimensionless thermo-economic performance of solar-dish Brayton system (68.65 kW, 0.2331 and 0.3077) are 22.6%, 34.9% and 18.4% respectively less than that of convectional Brayton heat engine. Finally, a range of functional relationship between the optimized objectives in Pareto frontier is fitted to provide more detailed insight into the optimal design of solar-dish Brayton system.     

The design and development of an axial flux permanent magnetbrushless DC motor for wheel drive in a solar powered vehicle

This paper presents the development of a “weight-power trade-off” applicable to high-performance, power limited vehicles. The theory is then applied to the electric vehicle case to justify the pursuit of an “in the wheel” motor design. The singular benefits of axial flux geometry are discussed with reference to the particular requirements of electric motors for vehicular applications. The basic design process, construction, and test results for a motor fitted in a 26 inch wheel to drive a 260 kg all up weight vehicle are presented. At an output power of 1 kW, the attainable vehicle speed is 72 km/h, corresponding to a motor/wheel speed of 578 r/min and torque of 16.5 Nm, at an estimated motor efficiency of 94%     

Diesel engine exhaust treatment with a pulsed streamer coronareactor equipped with reticulated vitreous carbon electrodes

Reticulated vitreous carbon (RVC) has been shown to be useful for high-voltage and ground electrodes in gas-phase pulsed streamer corona reactors. RVC disks with large macroscopic porosity are placed perpendicular to the gas flow and the main axis of a cylindrical corona reactor. This electrode geometry produces streamers that propagate in the direction of the gas flow and are uniformly distributed in the cross section of the reactor. This highly electrically conductive material has large macroscopic porosity, thus allowing for gas flow through the electrodes with low pressure drop. Previous work has considered the effects of RVC electrodes on NO/NO_x removal from various test gases containing air, water vapor, and ethylene. The present studies show removal of NO/NO_x from the exhaust of a 5 kW diesel engine. Under cold reactor operating conditions (12°C) 81% NO and 53% NO_x could be removed at an energy yield of 4.8 g/kWh (based on NO). Furthermore, experiments with the combination of TiO₂ or γ-Al₂O₃ catalyst particles placed in the region between the high-voltage and ground electrode disks gave NO removal at energy yields of 29 g/kWh and 9 g/kWh, respectively, at about 100°C, and significant fractions of the nitrogen were recovered as NO₃^- deposited on the catalyst surface. The RVC electrode system without catalysts was found to lead to efficient ozone production (55-70 g/kWh) in dry air at room temperature     

Fundamental performance of triple magnetic circuit type cylindrical thermomagnetic engine

The engine essentially consists of a rotor made of temperature‐sensitive magnetic material and permanent magnets. When an object made of this material has a temperature distribution in the magnetic field, the force is generated in the direction from the low‐temperature side to the high‐temperature side by magnetic pressure. This paper describes the fundamental performance of the triple magnetic circuit type thermomagnetic engine. A triple magnetic circuit type engine with water‐cooling system has ben designed. The performance characteristics such as power, resistance loss, and the relation between the temperature of the rotor and the rotation speed have been measured, and compared with the characteristics of a single magnetic circuit type engine. The net power is a maximum value of 3.7 W at a rotation speed of 0.4 rps. The power of the triple magnetic circuit type engine per unit magnetic circuit is about 4 times larger than that of the single magnetic circuit type engine. The resistance loss is 1.7 W at the maximum power point. The total power is 5.4 W. Electromagnetic braking loss is about 25% of the total power. The rate of electromagnetic braking loss to the total power increases with the rotation speed. The disk type rotor with small electromagnetic braking loss has been analyzed. Electromagnetic braking loss of the disk type engine becomes about 95% smaller than that of the cylinder type engine. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 154(4): 68–74, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20127     

零电压零电流开关PWM大功率机车控制电源设计

分析了电力机车对DC110 V电源的性能要求和技术指标,采用零电压零电流开关(ZVZCS)PWM全桥变换电路作为主拓扑电路设计了一台新型的机午控制电源.对所设汁的软开关电源主电路进行了参数计算及关键元器件的选型;最后建立了 PSpice环境下的仿真模型,并采用所设计的电路试制了一台功率为8 kW、工作频率为20 kHz的机车用开天电源装置.仿真和样机的实验结果均表明该设计是正确而有效的.     

Flywheel size design considerations and experimental verification using a 50‐kW system for voltage sag compensator with flywheel induction motor

Flywheel energy storage systems can be used as an uninterrupted power supply system because they are environmentally friendly and have high durability. The use of a simple voltage sag compensator with a low‐speed heavy flywheel and a low‐cost squirrel‐cage induction motor/generator is proposed. First, the ability of the proposed system to maintain the load voltage at 100% when the grid is experiencing voltage sag is validated experimentally. Next, design guidelines for the flywheel stored energy are discussed. Experimental verification of a 50‐kW‐class system is carried out, and the results show good agreement with the developed design guidelines. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(1): 36–44, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21252     

一种四相开关磁阻电动机新型功率变换器的分析与设计

通过对两种常用的四相开关磁阻电动机(SR)功率变换器主电路的分析,并结合研制实践,给出了5.5kW四相SR新型功率变换器的设计实例和实验结果。     

测量航空发动机转速的便携式系统的开发

本文详细介绍了一种测量航空发动机转速的以FPGA(XC2S100E 6PQ208C)为测量转速核心处理芯片,嵌入式单片机(S3C2410)为数据处理器的便携式系统的设计方法.详细介绍了系统的硬件组成和软件设计,并利用ISE6.2的集成开发环境编写了测量转速的软件程序,给出了系统测量的仿真波形.仿真结果表明,该设计方案符合设计要求.     

超高速开关磁阻电动机设计

开关磁阻电机结构简单坚固,转子上无永磁体和绕组,特别适合超高速运行。针对超高速电机的运行特点,对超高速开关磁阻电机的多物理场一体化设计方法进行探讨,研制了一台6/2结构超高速开关磁阻样机,样机最高转速为130 000 r/min,功率为1 kW。为提高样机的起动转矩,改进了样机的转子结构,并基于有限元法对样机的电磁性能和动力学性能进行优化。采用自主开发的具有角度控制功能的开关磁阻电机专用集成电路SR3P10K07A作为控制系统的控制核心。最后对样机进行了实验,实验结果表明本文采用的设计方法、转子结构和专用芯片是可行和有效的。     

PEMFC发动机输出功率瞬态响应仿真研究

结合质子交换膜燃料电池(PEMFC)发动机的工作原理,建立电化学模型。在此基础上,利用MATLAB/SIMULINK软件平台建立电池的瞬态响应仿真模型。不考虑空气系统的时间滞后,影响电池动态响应时间的主要因素为扩散浓差极化,它限制了电流的变化率。以MarkV型发动机为实例,通过分析负载突变的情况下PEMFC发动机输出功率的瞬态响应特性,得出结论为燃料电池的电化学反应时间常数相对较小,从30kW到50kW突变负载时为122ms(误差为5%)。     

Development of voltage sag compensator and UPS using a flywheel induction motor and an engine generator

Flywheel energy storage systems are attracting attention as uninterruptible power supplies (UPS) from the viewpoint of environmental friendliness and high durability performance. Using a low‐speed, heavy flywheel and a low‐cost squirrel‐cage induction motor/generator, two applications are proposed: (1) an 11‐kW voltage sag compensator using a capacitor self‐excited induction generator without semiconductor converters and (2) a UPS composed of the flywheel system and an engine generator. Based on experimental results, an ideal voltage sag compensator and UPS are realized by the low‐technology flywheel system. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 74– 81, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20784     

Dynamic behavior of an island power system with variable‐pitch wind turbines under high renewable energy penetration and high wind speed

High penetration of renewable energy in a power system may cause the problem of power dispatching and stability. The detailed dynamic behavior analysis for such a system is therefore important to the planning and operation of the power system. This study discussed the dynamic characteristics of an island power system with variable‐pitch wind turbines under high wind speed and high small hydraulic output power. The system primarily consisted of three diesel engine power generation systems, three constant‐speed variable‐pitch wind turbines, a small hydraulic induction generation system, and lumped static loads. The maximum penetration of renewable energy in this system could reach almost 60%. Detailed models based on MATLAB/Simulink were developed to cater for the dynamic behavior of the system. The results suggested that this island power system can operate stably in this operational mode with the help of variable‐pitch wind turbines. This study can serve as an important reference for planning, operation, and further expansion of island power systems. Copyright © 2014 John Wiley & Sons, Ltd.     

220,000‐r/min, 2‐kW PM motor drive for turbocharger

This paper describes an ultrahigh‐speed permanent‐magnet synchronous motor drive, which is embedded in a turbocharger of an internal‐combustion engine. The electrical drive makes it possible to enhance output power of the turbocharger in a motoring mode and to retrieve combustion energy from exhaust gas in a regenerating mode. Computer simulations and experimental tests are conducted to examine various operation characteristics of a prototype. The experimental data demonstrate 220,000‐r/min operation at 2.2‐kW inverter output power, in good agreement with the simulation results and proving the feasibility of the proposed system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(3): 31–40, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20408     

燃料电池运行压力对整车燃料效率的影响

40 kW质子交换膜燃料电池动力系统可以作为小车发动机。讨论了该动力系统运行时的空气与氢气压力对燃料电池堆输出功率的影响,并综合讨论了对整体系统氢燃料效率的影响。实验数据表明,燃料电池动力系统在低压10.132 5 kPa(相对压力)运行时具有较高的整体系统氢燃料效率,为45%,而在较高压力101.325 kPa(相对压力)运行时具有相对低的整体系统氢燃料效率,为40%。     

Design of a Switched Reluctance Machine for Extended Speed Operation

This paper presents results from a design study on the feasibility of employing high-efficiency switched reluctance (SR) machines in minimal hybrid-electric vehicles. The application requirements are presented and highlight the constraining influences of the vehicle drive-line topology on the machine design. The benefit of continuous phase current excitation is reported for the first time, demonstrating that constant power at an extended-speed operation can be realized with a higher number of phase winding turns per pole than would otherwise be achieved with conventional discontinuous current control. Thus, the torque/Ampere capability, when operating at or below base speed, is not as significantly compromised, an important consideration for the power inverter rating and, hence, drive system cost. The design procedure and simulated results are validated by measurements from a prototype machine. The results demonstrate the potential of SR technology for high-performance low-cost automotive applications, which often combine arduous environmental and volumetric constraints. In addition, the results highlight the benefits of continuous current control for extended-speed operation.     

开关磁阻起动/发电机设计方法研究

开关磁阻起动/发电机是电动机与发电机的结合体。提出一种将经典电机设计与最新有限元设计相结合的电机设计方法,该方法将传统设计方法的快捷、简便与有限元设计方法的精确、直观等优点相结合。并且采用以发电机性能为主,兼顾起动性能的设计方式;在多场有限元联合仿真的基础上,设计并试制了一台循油冷却开关磁阻起动/发电机。实验证明,该设计方法适合于该类型电机。     

A study of integral sliding mode control with input constraint for engine idling‐speed control

This paper proposes an approach to the provision of sliding mode control (SMC) with input constraint for engine idling‐speed control. The aim of this experiment is to improve the stability of the system against disturbances such as fuel purges and torque loads. A steady‐state error occurs because, in practice, the control input is restricted when an integral type SMC is employed to achieve stabilization. A modification to this approach is proposed that effectively uses compensation gain and variable switching gain. The compensation gain is derived from the control input difference, and the variable switching gain is described as an exponential function of the hyperplane. A mean‐value engine model with dead time and disturbances is constructed in Matlab/Simulink. The simulation results show that the issue relating to steady‐state deviation can be successfully solved with regard to disturbances having bias power; also, robustness is maintained during engine speed fluctuations. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

内燃发电机组冷热电联供系统集成式热管理器的设计

内燃发电机组冷热电联供系统作为一种分布式能源供应系统，具有能源利用率高，经济性好等优点。在实际运行过程中，需要同时解决缸套水温度控制、余热回收与管理等多个问题。为解决这些问题，该文提出集成式热管理器的概念。该热管理器既可以控制缸套水温度，又可以实现多品位热源输入、多种类热用户热量输出和余热热能管理等多种功能。文中介绍了其运行原理和热管理思路，并基于微型冷热电联供实验系统，给出了热管理器工程样机的具体设计实例。模拟结果表明，微型冷热电联供系统发电功率从空载到满负荷12kW发电的过程中，在不同余热利用工况下，内燃发电机组缸套水进口温度都可以控制在84~89°C，同时具备良好的余热热能管理功能。