共查询到18条相似文献,搜索用时 234 毫秒
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基于MATLAB/SIMULINK动态仿真模型的高转矩软起动器研究 总被引:10,自引:0,他引:10
介绍了一种能使软起动器实现分级变频的方法 ,它能使电机以高转矩和较小起动电流平滑起动 ,且控制简单 ,成本低廉。该方法是通过改变工频电压半波的数量和顺序 ,使输出电压频率离散地增加到50Hz。本文基于MATLAB5.3/SIMULINK ,对三相交流异步电机和采用分级变频的软起动器进行建模与仿真 ,将仿真结果与传统电子软起动器进行比较 ,证明采用分级变频的软起动器可以使电机减小起动电流、增大起动转矩 ,还可使电机短时运行于低速状态 相似文献
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分级变频软起动器触发控制策略研究与仿真 总被引:1,自引:0,他引:1
介绍了分级变频软起动器的工作原理,限制电机起动电流的软起动器。这种软起动器对传统软起动器的电路结构进行了改造,通过对晶闸管的控制实现对电压频率的离散控制,即分级变频。经过对子频率的相位研究,采用转矩最大的正序组合并在频率分级起动的同时结合调压起动的方法。最后通过仿真试验,证明了此种分级变频调压软起动器可以有效地提高起动转矩降低起动电流。 相似文献
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车用内嵌式永磁同步电机运行性能受到电机参数及控制器输出能力的限制.为了提高永磁同步电机单位电流输出转矩的能力以及对电机参数的鲁棒性,该文提出了一种转矩角闭环的最大转矩电流比控制策略.该策略通过永磁同步电机的数学模型推导出在同步dq轴系下以定子电压、电流为变量的电磁转矩方程,并以此为依据构建出满足最大转矩电流比的转矩角β的闭环控制系统,摆脱了永磁同步电机最大转矩电流比控制对电机参数的依赖,提高了控制准确性.仿真和实验结果验证了所提控制策略的可行性和有效性. 相似文献
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《微特电机》2017,(3)
对于三相异步电动机,离散变频是一种新颖的能有效提高电机起动转矩的新型控制方法,但其存在电磁转矩脉动严重和电流有效有效值较大的缺点。为克服该缺点,首先从定子空间电压矢量分析基于周波控制的离散变频工作过程,明确定子电压矢量的重复触发是该离散变频产生电磁转矩脉动的原因。然后利用六边形空间电压矢量原理提出基于空间电压矢量的离散变频控制方法,将一个周期的电压矢量减小至6个,避免了电压矢量重复触发或反方向导通,以减少电磁转矩脉动。最后从定、转子电流和电磁转矩仿真对比两种离散变频起动过程,结果表明基于空间电压矢量的离散变频起动转矩更大、起动更加平稳,起动过程性能明显优于基于周波控制的离散变频。 相似文献
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针对摆式砂锯机重载起动特性,提出了一种基于离散变频策略的电机软起动方法.采用MATLAB/Simulink建立了电机离散变频软起动模型,研究了离散变频起动时产生最大转矩的晶闸管最优触发顺序,并以TI公司生产的TMS320LF2407A DSP芯片为核心,完成了摆式砂锯机电机软起动器的设计.仿真和实验结果表明,软起动器能... 相似文献
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基于分级变频的重载软起动系统 总被引:1,自引:0,他引:1
介绍了一种增大电机起动转矩的控制方法。它不改变传统软起动的主电路结构,通过控制晶闸管导通一个或多个半波时间,在电机端得到新生基频电压。由于新生基频电压相位生成有很多种方式,为了得到最优的生成系统,使转矩最大,考虑了3种系统下各次谐波对系统的影响,并通过仿真给出了结论。 相似文献
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介绍了软起动器装置中晶闸管触发系统的设计。重点阐述了软起动器的工作原理、软硬件设计、触发时序设计和波形分析。通过对串接于三相电网与三相异步电动机之间的三路反并联晶闸管的触发角度和时序控制,解决了电动机直接起动时产生的冲击电流和冲击转矩问题。 相似文献
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新型软起动最小转矩脉动的控制策略研究 总被引:1,自引:0,他引:1
研究了基于自关断器件的新型软起动。分析了新型软起动的摹本原理和工作特性,给出了软起动系统的数学模型,重点研究了电机起动过程中的转矩脉动问题。在仿真分析电机连接三相系统时定了电压的第一个系统周期内开关时刻与转矩脉动关系的基础上,给出了转矩脉动的控制策略。利用开关时刻计算函数,得到施加电压的最佳开关时刻。按照此开关时刻施加电压,可以减小甚至消除电机起动时的脉动转矩。实验结果证明该方法对于新型软起动是切实可行的。 相似文献
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Chih‐Ju Chou Chun‐Yao Lee Chun‐Chi Chen Chao‐Rong Chen Mu‐Cheng Chen 《IEEJ Transactions on Electrical and Electronic Engineering》2014,9(2):136-143
This paper proposes the optimal planning of soft starter characteristics for a large drain motor based on simulated annealing (SA). First, the planning of the soft starter characteristics is formulated as an optimization problem with minimal motor starting time; then, the constraints of the motor starting energy, power quality requirements, and minimal cost of transmission line are constructed. The system framework of an actual case in Taiwan is used as the basis of this study with simulation. Before and after the installation of three sets of soft starters, measuring instruments are used in the field to investigate the changes of current and voltage during the motor starting, thus establishing the database of current swell and voltage sag. The searching algorithm based on the SA method is developed by the program MATLAB, such that the soft starter can regulate the minimal motor starting time and meet the above‐mentioned constraints. According to the model of the system circuit and the characteristic parameters constructed by an actual case, the simulation results verify the superiority of the proposed SA method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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The electric submergible pump (ESP) consists of a centrifugal pump powered by a medium-voltage three-phase induction motor. Being constrained to operate within common well casings, the ESP is rather unique; for example, a 500-hp motor may be less than 6 in in diameter and more than 100 ft long. As such, its mechanical rotational behavior under starting conditions can be severe, and some actions normally thought to attenuate the severity can actually amplify it. Both analytic and experimental approaches to understanding the starting incident and its effects are presented. A model was developed to predict the electrical and mechanical conditions prevalent when starting with various types of reduced-voltage fixed-frequency starters. These include the solid-state soft starter, reduced-voltage starters using variable or switched series impedances and stepped-voltage starters. Direct on-line full-voltage starting was used as a base case. Model predictions for the various starting methods were compared against tests measuring transient speed, voltage, current, and torque. Test results indicate that some starting techniques can produce unstable operation, i. e., torsional vibration. In large horsepower ESP's shaft strength safety factor is reduced due to space limitations and torsional vibrations must be minimized to avoid breakage due to fatigue. Depending on the application, configuration of the ESP and adequacy of available power, good motor starter design can be crucial to reliability. Finally, it is believed that this work has direct applicability to the starting of many more common large induction motors. 相似文献