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本文主要阐述了三相异步电动机的转子结构、鼠笼式异步电动机的启动、绕线式异步电动机的启动、三相异步电动机的制动等异步电动机的几个技术问题。 相似文献
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生产机械在电动机的拖动下运转,在电动机失电后,由于惯性作用电动机不可能立即停止下来,而会继续转动一段时间才会完全停下来。为了使电动机迅速停转,就要对电动机采取制动措施。电气设备中使用较多的一种制动措施就是反接制动,也就是在电动机定子绕组切断三相电源惯性运转时,在其定子绕组中接入三相电源且改变电源相序,从而产生一个与其转动方向相反的制动力矩,迫使电动机迅速停转。 相似文献
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永磁同步电动机的启动电流比普通感应电动机的大,本文通过设计新型开闭口槽相结合的转子形式控制永磁电机的启动电流,把现在表贴式永磁体更改为,安装在转子内部,保证永磁体可靠,不脱落,不易损坏。 相似文献
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在交流电动机的变频调迷中,如果能保持转子磁通不变,即可有同直流电动帆相同的机械特性,从而有像直流电动机那样良好的调速特性。利用GA方法．快速找到实现转子磁通不变时所需定子电压,提高异步电机的运行性能。 相似文献
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发电电动机转子是抽水蓄能机组的核心部件之一,随着蓄能机组的设计、制造向大型化、高转速发展,发电电动机转子磁轭在工地的装配质量的优劣,对机组的安全、稳定运行至关重要。发电电动机转子磁轭现场装配程序繁琐,工艺复杂,装配方式随转子结构的不同而采取的工艺措施有所差异。本文详细介绍了广东某抽蓄电站发电电动机转子磁轭装配流程、工艺过程和质量要求,并对重点部分加以插图进行阐述,为其它蓄能电站发电电动机转子装配提供一定的借鉴。 相似文献
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介绍了基于AT89S52单片机,利用红外传感器直流电机的转速,控制直流电机的转动速度,用PWM调速方式控制直流电机转动的速度,以及停止转动,并可以自动调节速度至预先设定的速度。整个系统的电路逻辑结构简单,可靠性高,实现功能强。 相似文献
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Jediael Machín Almeida Alexander G. Loukianov José M. Cañedo Castañeda Jorge Rivera Dominguez 《Journal of The Franklin Institute》2018,355(7):3221-3248
Using a nonlinear complete order model of a synchronous motor, a robust second order sliding mode observer based control scheme is proposed. For that, a generalized super-twisting 3rd order observer is proposed for nonlinear systems. Based on the proposed observer scheme, a robust rotor flux observer is designed, then, a stator current observer is proposed using a classical super-twisting algorithm for extracting information of the rotor speed by means of the equivalent control method. The control design for the output tracking of a desired reference signal for the rotor speed is carried out with a classical super-twisting sliding mode algorithm and adaptive backstepping techniques. Due to the number of inputs, the flux in the excitation winding, and the direct component of the stator currents are also regulated. Numeric simulations predict a good performance of the closed-loop synchronous motor with parameter variations. 相似文献
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通过介绍空间电压矢量脉宽调制(SVPWM)控制策略在无速度传感器矢量控制系统中的实现,在此基础上给出了基于DSP的全数字化调速系统,并分别建立了改进的电压型转子磁链观测模型和PI自适应速度估算模型。实验结果表明:所采用的控制方法正确可行,控制系统具有良好的性能。 相似文献
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Hamdi Echeikh Ramzi Trabelsi Atif Iqbal Med Faouzi Mimouni 《Journal of The Franklin Institute》2018,355(5):2112-2141
High performance multiphase motor drive requires precise knowledge of the state quantities and the machine parameters. Access to these state quantities is through measurement using sensors whose accuracy is paramount to achieve the performance level required by industrial applications. However, the problems of the parameters variations, inaccessibility to the measurement of some states, no-observability of the machine in some regions, the cost of the sensors and their lack of precision, make this very difficult task. To address these problems, it is necessary to resort to soft sensors through the design of observers and estimators. In multiphase induction motor drive, the observation problem arises especially for rotor flux that is not accessible for measurement. About the parameters variations, the rotor resistance and the stator resistance are the most critical parameters of the machine because their influence is crucial for the control and observation. The change in the resistances can be as large as 40–50% of the rated value, which may affect the control adversely. This paper develops a new structure of an adaptive sliding mode observer based on an online estimation of the rotor resistance value in order to avoid the effect of its variation in the rotor flux oriented control. The results show convergent (the errors in the transient and steady states are 5% and 1%, respectively) behavior of the drive using the proposed control scheme for large rotor resistance variation under loaded condition. The stability of the drive is proved using Lyapunov criteria. The simulation results are validated using real time implementation. 相似文献
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Sedat Sünter 《Journal of The Franklin Institute》2008,345(4):419-435
This paper investigates rotor-side field oriented control of a wound-rotor induction motor using the slip energy recovery principle. The proposed drive system uses a matrix converter to transfer the slip energy from the rotor into the mains instead of using ac-dc-ac converter whilst the stator side is fixed to the grid. Operation at both subsynchronous and supersynchronous regions is possible with the proposed drive system. Simulation studies of the proposed doubly fed induction motor drive system verify the good control performance of the system in transient and steady-state conditions. 相似文献
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Jyoti P. Gurung Moein Navvab Kashani Sanaz Agarwal Gonzalo Peralta Murat Gel Matthew A. B. Baker 《Biomicrofluidics》2021,15(3)
Many motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through membrane protein complexes known as stators, with the next most common ionic power source being sodium. Sodium-powered stators can be studied through the use of synthetic chimeric stators that combine parts of sodium- and proton-powered stator proteins. The most well studied example is the use of the sodium-powered PomA-PotB chimeric stator unit in the naturally proton-powered Escherichia coli. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria while varying the ionic composition of the media and thus the sodium-motive force available to drive this chimeric flagellar motor. We measured separation efficiencies at varying ionic concentrations and confirmed using fluorescence that our device delivered eightfold enrichment of the motile proportion of a mixed population. Furthermore, our results showed that we could select bacteria from reservoirs where sodium was not initially present. Overall, this technique can be used to implement the selection of highly motile fractions from mixed liquid cultures, with applications in directed evolution to investigate the adaptation of motility in bacterial ecosystems. 相似文献
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本文介绍了利用PLC改造T68型卧式镗床的电气控制系统的思路和方法,对T68卧式镗床主轴电动机M1的正反转的点动控制,正反转高速控制,正反转停车制动控制,主轴变速控制和对镗床控制系统的主电路、辅助电路和控制电路等电路进行了设计和调试。改造后车床运行稳定,降低了故障率,提高了生产效率。 相似文献
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Oscar Barambones 《Journal of The Franklin Institute》2013,350(10):3441-3447
This short communication is a discussion of the paper entitled “Adaptive sliding-mode-observer for sensorless induction motor drive using two-time-scale approach” by A. Mezouar, M.K. Fellah and S. Hadjeri published in the Simulation Modelling Practice and Theory 16 (2008) 1323–1336. In the discussed paper the authors present a current and flux sliding mode observer for the induction motor that also incorporates an adaptive laws in order to estimate the rotor speed and the inverse of the rotor time constant. However the proposed design for the observer and for the adaptive laws, employs the real value of the rotor time constant and the real value of the rotor speed, which are unknown, and therefore cannot be used in the observer design nor in the adaptive laws design. 相似文献