三相异步发电独立电力系统不对称稳态运行分析

建立了三角形接法鼠笼式异步发电机三相负载不对称时独立系统的数学模型,对该独立系统中各电量之间的关系进行分析,计算发电机三相输出电压及绕组电流大小。基于对称分量法,推导出发电机侧正序和负序等效电路,并求出三角形连接的负载侧序电压与序电流之间的关系,进而得出满足发电机稳态运行要求的目标函数,省去了复杂的电路分析。针对稳态运行方程的非线性及复杂性,采用优化算法求解出系统的频率和正序电抗,并以此为基础计算系统的稳态电压值。计算值与实测值吻合度较高,表明所提目标函数的正确性以及所采用优化算法的准确性和有效性。     

Electric output power of a commercial induction motor used as an induction generator

The generator mode of a commercial motor is examined. It is shown that, under the main rated voltage, the output power in the generator mode is less than the motor output power rating. At a smaller value of the main voltage, the output power in the generator mode increases.     

The cascade induction machine: a reliable and controllable motor or generator

This paper discusses and analyses a set of two induction machines, with 2p and 2q pole-pairs, respectively, connected in cascade. It highlights the design and development principles of a single unit version of a system consisting of two wire-wound rotor induction machines with their rotors connected in cascade. Presented performance analysis shows the described cascade machine, which is brushless and with no slip rings or commutators, as a reliable, efficient and practical machine that could replace the induction machine, which has a wire-wound rotor. An example of the conversion of a standard squirrel cage six pole induction machine into a (6+2) pole induction machine, without rewinding the stator, is also presented together with simulation and measurements for asynchronous and synchronous modes of operation.     

The dynamic characteristics of an isolated self-excited induction generator driven by a wind turbine

This paper presents the effect of magnetizing inductance on self-excitation. It also describes the loading analysis of an isolated induction generator, and how the operating frequency and generated voltage are affected by the change in operating slip value for regulated and unregulated rotor speed. Wind-powered self-excited induction generators have an input wind which is not controllable, but they can be set to operate within a given variation of speed. The experimental and simulated results for a dynamic generated voltage, frequency, and power are presented. The dynamic electromagnetic torque produced by the induction generator is also given. A dSPACE DS1102 digital signal processor card is used for data acquisition and for control of the driven speed.     

基于Buck-Boost矩阵变换器的异步电机调速系统控制策略

针对以Buck-Boost矩阵变换器(BBMC)为功率变换器的异步电机调速系统,提出一种基于有限时间控制的变频调速控制方法。首先,根据异步电机的给定转速,经基于PI-IP控制的矢量控制算法获得异步电机的给定电压,并以该给定电压作为BBMC的参考输出电压。再以BBMC中电容电压与电感电流作为系统控制变量,经有限时间控制算法得到BBMC中对应功率开关的占空比。再根据该占空比对BBMC中对应功率开关实施控制,由此可在BBMC输出端获得与其参考输出一致的输出电压,从而实现异步电机实际转速对其给定转速的准确跟踪,达到对异步电机转速进行准确控制的目的。最后通过仿真和实验对上述控制方法进行了验证。     

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     

异步电机矢量变换控制系统的MATLAB／SIMULINK仿真

根据矢量变换控制原理 ,利用MATLAB/SIMULINK软件构造了异步电机矢量变换控制的数学模型。重点介绍了电机模型和转子磁链模型的建立 ,仿真结果证明了该方法是有效的     

Analysis of a polyphase synchronous reluctance motor with two identical stator windings

This paper presents the performance analysis of a cageless two-stator-winding reluctance motor which is capable of developing reluctance torque at good power factors in the absence of inverter control. The machine stator has two separate identical polyphase windings whose pole numbers are the same as that of the cageless rotor. The machine performance is investigated using the traditional circle diagrams, and the d–q rotor reference frame equations derived in space-vector form by applying the concept of winding functions. Core loss and saturation are accounted for in the developed dynamic model. It is shown that if one winding is connected directly to the supply and the other fed with a balanced capacitor, the developed torque is superior to a brushless doubly-fed reluctance machine (BDFRM) of similar size. Other motor characteristics, its line-start behaviour and torque ripples are also presented and discussed. Experimental results corroborate the simulations.     

Optimization of a variable-frequency induction motor drive with a scalar control system

The structure of an upgraded frequency control system and procedures for calculating control laws for induction motor drives under static and dynamic conditions are considered. The results of mathematical simulation and experimental investigation of the processes in a standard and an upgraded scalar control system are discussed.     

定子双绕组感应发电系统的滞环电流控制方法

提出了一种基于空间电压矢量的适用于定子双绕组感应发电系统的滞环电流控制新方法.该方法将滞环控制与空间电压矢量PWM控制相结合,根据控制绕组的电流误差矢量与参考空间电压矢量的区域分布,选择最佳的电压矢量运行,使各相电流误差被限定在给定滞环内,准确跟踪各相给定电流,实现静止励磁控制器三相桥臂间的关联控制,消除相间影响.该方法实现简单,即能限制开关频率,又能有效减小电流误差,改善电流跟踪性能.实验结果证明了该方法的正确性和有效性.     

三相无轴承异步电机的解耦控制系统

为适应无轴承运行控制技术走向高速大功率领域的需要,对三相无轴承异步电机的控制模型、策略和系统进行研究和设计.经理论解析推导出激磁电感模型、基于转矩系统气隙磁链的可控磁悬浮力模型和不稳定单边磁拉力解析式,给出单边磁拉力前馈补偿方法,详细介绍四极转矩控制系统和二极磁悬浮控制系统的结构和控制原理;针对样机进行磁悬浮解耦控制系...     

大功率感应电机矢量控制系统软硬件设计

根据大功率感应电机矢量控制的特点,设计了一种基于浮点型数字信号处理器ＴＭＳ３２０Ｃ３１和单片机８０Ｃ１９６ＭＣ的双微机矢量控制系统,并详细说明了其软硬件设计方法。实验结果表明,该控制系统充分利用了ＴＭＳ３２０Ｃ３１和８０Ｃ１９６ＭＣ的特点,软硬件设计合理、实时性好,能可靠地完成复杂的矢量运算和优化 ＳＰＷＭ波形生成,控制感应电机达到较好的动态性能。     

中小型防爆异步电动机的冷却系统

电气技术行业对铜使用量最大 ,异步电动机是机械制造业的主要产品之一 ,其中包括防爆异步电动机。截止目前 ,实际上已经采取的各种各样可能的措施来降低金属的使用量 ,并极大地限制了在不增加金属用量的情况下提高效率的可能性 ,因为缺乏热传导性更高的绝缘材料 ,而槽填充系数和导磁率也已经接近极限值。使用传热性能更强、又具有足够强度的材料来代替现有材料制造异步电动机的外壳是一个非常大的问题。由于外壳表面温度、降低效率以及缺乏更有效的轴承耐热润滑剂和涂层等因素的影响 ,从而限制了耐热绝缘材料的使用 (高于抗热等级Ｈ级 )。要…     

基于MATLAB/SIMULINK的交流电机调速系统建模与仿真

根据直接转矩控制原理,利用ＭＡＴＬＡＢ／ＳＩＭＵＬＩＮＫ软件构造了一个交流电机调速系统,系统能够很好模拟真实系统,实现高效的调速系统设计、仿真结果证明了该方法的有效性。     

Rail brake system using a linear induction motor for dynamic braking

One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. We estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(2): 29–38, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21209     

An integrated flywheel energy storage system with homopolar inductor motor/generator and high-frequency drive

The design, construction, and test of an integrated flywheel energy storage system with a homopolar inductor motor/generator and high-frequency drive is presented in this paper. The work is presented as an integrated design of flywheel system, motor, drive, and controller. The motor design features low rotor losses, a slotless stator, construction from robust and low cost materials, and a rotor that also serves as the energy storage rotor for the flywheel system. A high-frequency six-step drive scheme is used in place of pulsewidth modulation because of the high electrical frequencies. A speed-sensorless controller that works without state estimation is also described. A prototype of the flywheel system has been demonstrated at a power level of 9.4 kW, with an average system efficiency of 83% over a 30000-60000 r/min speed range.     

双馈风力发电机组对电力系统稳定性影响

双馈感应发电机(DFIG)在定子磁链或电压定向的矢量控制下,其功角动态行为均具有快变特性,致使DFIG对常规同步发电机(SG)的首摆稳定性和阻尼特性产生重要影响.研究发现,DFIG和SG的功角摇摆曲线可能存在两类交点,将其分别定义为主动交越点和被动交越点,交越性质决定了DFIG对SG稳定性影响的性质.大扰动时,SG的首摆期间有主动交越交点,DFIG降低了系统的暂态稳定性;后续摇摆期间有被动交越交点,DFIG起到了正阻尼作用.