共查询到20条相似文献,搜索用时 156 毫秒
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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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采用分级交-交变频方法的高转矩软起动器的研制 总被引:6,自引:0,他引:6
介绍了一种采用分级交-交变频方法的交流电机软起动器的原理和实现,它能使电机以高起动转矩和小的起动电流平滑地起动。并将实际效果与传统的电子式软起动器进行了比较,证明采用分级交一交变频方法的软起动器,不仅可以减小起动电流,提高起动转矩,还可以实现真正的软停车及使电机短时工作在低速运行和反转制动状态。 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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大中型笼型异步电动机电容起动的研究 总被引:1,自引:0,他引:1
详细描述了大中型笼型异步电动机电容起动的特点,给出了电容初步设计的原则瑟步骤,建立了三相笼型异步电动机电容起动系统的数学模型,并进行仿真计算。理论分析和仿真实例表明,异步电动机采用容起动,可以明显降低起动电流,保持较高的起动转矩,减少起动时间,是一种可供选择的新型起动方法,值得研究与开发。 相似文献
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ABSTRACT Increasing concerns over the starting of induction motors with high starting torque requirements have prompted engineers to seek methods of starting with full voltage and switched capacitors. This method provides ample acceleration torque with minimum voltage disturbances on the main bus. A highly reliable microprocessor-based starter with high performance has been developed. The hardware and software architecture of this starter and its starting aspects are described. The programmable automation provided here allows a flexibility in algorithms which can be altered or expanded easily. The performance goals designed also include protection of induction motor against overload, phase loss, wrong phase sequence and severe over voltage due to self-excitation. 相似文献
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A reluctance network analysis (RNA), which is an improved magnetic circuit method, has some advantages: the analytical model is simple, the calculation accuracy is relatively high, and a coupled analysis with an electric circuit, a heat circuit, a motion equation, and so on, is fundamentally easy. The RNA has been applied to the dynamic analysis of several motors such as a surface permanent magnet (SPM) motor, an interior permanent magnet (IPM) motor, and a switched reluctance (SR) motor. The dynamic characteristics of these motors including starting and a sudden load change can be calculated by an RNA. However, the torque calculation methods for these motors are different from each other. This paper presents a unified calculation method for the motor torque in an RNA, which does not depend on the types and structures of motors. The validity and availability of the proposed method are demonstrated by a finite element method (FEM) and an experiment. 相似文献
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基于电磁转矩复解析小波变换的感应电机转子故障检测 总被引:3,自引:2,他引:1
提出一种运用电磁转矩信号对感应电机转子断条故障进行检测的新方法.当感应电机转子发生断条故障时,转子绕组的不对称将会使电磁转矩中引入2s同步速的脉动转矩(s为转差率).对电机起动电磁转矩信号进行复值小波变换,根据分析小波在特定中心频率条件时信号瞬时频率与其对应小波脊线的关系,提取出故障特征转矩频率变化规律,实现转子故障的可靠检测.同时,对应尺度上小波系数的模值还能够反映该故障特征转矩在电机起动过程中的幅值变化规律,将其作为故障严重程度指标则可以进一步判断转子断条根数.实验结果证明了该方法的有效性. 相似文献
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Mutoh N. Ueda A. Nandoh K. Ibori S. 《Industry Applications, IEEE Transactions on》1992,28(5):1031-1037
The control method described prevents general-purpose inverters without current regulators from tripping easily, i.e. to be tripless no matter how their load is varied, and enables motors to rotate stably at high frequencies. It uses only current sensors and is a combination of pulse-width-modulated (PWM) control and torque control. The PWM control changes an asynchronized mode to a synchronized mode when the modulation ratio becomes more than one, enabling the carrier wave frequency to be continuously varied with the inverter frequency so that motors can rotate stably over a wide frequency range. The torque control uses a real and reactive component detector, magnetic flux compensator, slip compensator, and current limit controller. Experiments prove that this tripless control can be satisfactorily applied to general-purpose inverters 相似文献
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建立高转速振动电机的d-q系统数学模型,指出通过调整电机铁心长度、线圈匝数可优化设计电机的起动过程,控制电机的起动时间。分析了实例电机起动过程的转速特性曲线、转矩特性曲线、电流特性曲线,指出高转速振动电机起动过程中,转速变化存在近似线性特征,不存在“超同步现象”和转矩特性“摆动现象”。 相似文献
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When starting motors with high inertia loads across the line, it is common practice to determine load inertia and then make acceleration time calculations. Comparing acceleration time to the motor's maximum allowable time to accelerate, the motor can be used or, if necessary, the next larger rating may be required because the acceleration time with a particular inertia is too long. It is not uncommon to find a motor to be sized for the starting/accelerating load instead of the running load in applications with high inertia loads. What should be done differently when an adjustable speed drive (ASD) is applied on these loads with high inertia? In this article, a method is established to calculate running torque, calculate starting/accelerating torque, and size the motor and the ASD appropriately 相似文献