共查询到20条相似文献,搜索用时 187 毫秒
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船用发电机的转子绕组因通过电压低、电流小、结构比定子简单等原因,在日常电机制造及检验过程中,匝间绝缘的监测容易忽视,而且IEC 60034以及IEC 60092等国际电工委员会颁布的标准中也没有对此提出明确要求。但是, 基于对产品质量及性能的可靠性保障,转子匝间耐压测试是有必要的,特别对高压电机产品的转子匝间绝缘监测,以验证匝间绝缘对陡峭前沿的操作过电压的承受能力。以制造厂进行的高压发电机转子匝间试验为例,介绍了测试方法、故障现象及异常分析三部分内容,包含了以脉冲波形判断发电机转子部分的绝缘异常,以及制造过程中接地电阻的问题。 相似文献
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当一款发电机定转子主要尺寸定型后,转子的阻尼绕组性能是影响发电机超瞬态电抗的最主要因素。在不同的工况下,用户对发电机的超瞬态电抗的性能有不同的要求。通过阻尼绕组的调整基本可实现超瞬态电抗的调整。通过对1台3 MW无刷同步发电机转子阻尼绕组采用不同材质或不同的阻尼条数的设计方案,对超瞬态电抗值进行计算和分析,并通过低电压突然短路测试方式验证了不同方案对超瞬态电抗值的影响,以获得最佳的阻尼绕组设计方案。 相似文献
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研究了绕组短路故障对直接驱动作动器(DDA)用电气/机械混合四余度无刷直流力矩电动机(BLDCTM)性能的影响。基于电气/机械混合四余度BLDCTM的数学模型,分析了短路故障对电机电气参数造成的影响,并且建立了绕组匝间短路和相间短路这两种短路形式下的等效电路模型。电机系统的仿真结果表明,本文所采用的低转速电气/机械混合四余度BLDCTM某一相绕组出现匝间短路或某余度的两相绕组出现相间短路时,DDA系统依然可以正常运行。电气/机械混合四余度BLDCTM完全可以克服绕组短路故障的影响,提高了DDA系统的可靠性。 相似文献
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将负序电流作为异步电机定子绕组匝间短路的故障特征量,在提取时易受谐波、噪声等因素的影响,而频谱分析也较为复杂,故障诊断的可靠性和高效性难以兼顾。为可靠高效地诊断异步电机定子绕组匝间短路,在多次派克变换的基础上,提出故障特征量Izpg以反映故障。首先根据故障后的电机磁场推导出故障后定子中存在的电流频次;然后得到非理想工况下,利用多次派克变换提取故障特征量Izpg的表达式;最后建立故障后异步电机的多回路数学模型,对理想工况和非理想工况下定子不同严重程度的匝间短路进行仿真。分析结果表明,Izpg和故障严重程度正相关且对电压源不平衡这类非理想工况呈现鲁棒性,用Izpg诊断异步电机定子匝间短路具有高灵敏性与高可靠性。 相似文献
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双馈异步发电机(DFIG)在长期运行中很容易发生定转子绕组过热故障。以绕组温度为研究对象,在分析绕组过热故障成因的基础上,分别从电机热性能和参数辨识两方面进行检测。使用参数辨识法时,首先利用电机电磁数学模型辨识定转子绕组电阻,再根据电阻与温度之间的关系计算定转子温度,从而判断绕组是否过热。最后基于MATLAB软件仿真验证了定转子绕组参数辨识法的正确性,为DFIG诊断绕组过热故障提供理论支撑。 相似文献
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当船舶轴带无刷双馈电机(BDFG)功率绕组发生三相短路故障时,短路电流会对系统造成较大的危害。因此,有必要设计专门的保护电路保障系统的安全。利用空间旋转坐标系,建立船舶轴带BDFG功率绕组三相短路时的动态方程,并依据磁链守恒定律研究系统短路电流的变化特性。通过分析短路电流的各个分量,提出加入撬棒电阻和直流卸载电路的保护方式来卸载过电流,并进一步研究加入保护电路后的电流变化特性。以1台30 kVA的BDFG为仿真对象,运用MATLAB/Simulink进行模型仿真和理论值计算,验证了保护电路的有效性,对船舶轴带BDFG电气安全设计具有指导意义。 相似文献
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Chin-Hsing Cheng Yuan-Yih Hsu 《IEEE transactions on aerospace and electronic systems》1991,27(2):247-254
A scheme involving the use of a lookup table is developed for the excitation control of a synchronous generator. The proposed control scheme, generator speed deviation, and acceleration deviation are taken as the input signals. These input signals are sampled and converted to linguistic terms before they are fed into the controller. The controller generates the desired output (control) signal by using a set of production rules (if-then rules) that are based on previous experience to relate the input signals to the output. The output signal is converted from linguistic terms to a numerical value before it is sent to the excitation system of the synchronous machine. To demonstrate the effectiveness of the proposed control scheme, digital simulations of a synchronous generator subject to a three-phase fault under different operating conditions were performed. It was found that the controller can improve the dynamic performance of a synchronous generator over a wide range of operating conditions. Since the controller does not require model identification, it is computationally efficient and is suitable for online excitation control, using a microcomputer 相似文献
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A novel fault tolerant permanent magnet synchronous motor with improved optimal torque control for aerospace application 总被引:2,自引:2,他引:0
Improving fault tolerant performance of permanent magnet synchronous motor has always been the central issue of the electrically supplied actuator for aerospace application. In this paper, a novel fault tolerant permanent magnet synchronous motor is proposed, which is characterized by two stators and two rotors on the same shaft with a circumferential displacement of mechanical angle of 4.5. It helps to reduce the cogging torque. Each segment of the stator and the rotor can be considered as an 8-pole/10-slot five-phase permanent magnet synchronous motor with concentrated, single-layer and alternate teeth wound winding, which enhance the fault isolation capacity of the motor. Furthermore, the motor has high phase inductance to restrain the short-circuit current. In addition, an improved optimal torque control strategy is proposed to make the motor work well under the open-circuit fault and short-circuit fault conditions. Simulation and experiment results show that the proposed fault tolerant motor system has excellent fault tolerant capacity, which is able to operate continuously under the third open-circuit fault and second shortcircuit fault condition without system performance degradation, which was not available earlier. 相似文献
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Vadher V.V. Kettleborough J.G. Smith I.R. Gerges W.R. 《IEEE transactions on aerospace and electronic systems》1989,25(4):508-519
A generalized model is described for a brushless DC machine consisting of a multiphase synchronous machine with a full-wave bridge rectifier connected to its output terminals. The state-variable equations for the machine are suitable for numerical integration on a digital computer, and are assembled in a form which permits investigations to be made on the effects of different numbers of armature phase windings and different winding connections. The model has been used in both steady-state and transient studies on a number of generating units, with the detailed information which is provided being beneficial to design engineers. Comparisons presented between predicted and measured results illustrate the validity of the model and the mathematical techniques adopted, and confirm that accurate information on the performance of a brushless generator may be obtained prior to manufacture 相似文献
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基于故障字典的旋转整流器故障检测方法 总被引:1,自引:0,他引:1
朱新宇 《中国民航学院学报》1999,17(6):16-19
以交流电为主要电源的飞机普遍采用无刷交流发电机作为发电装置,但由于半导体器件抗干扰、抗过载能力差,旋转整流器成为故障发生率较高的部件,文中介绍了利用快速傅里叶变换(FFT)通过对励磁电流的分析来检测可能出现的故障,并利用故障字典快速地判断出故障原因。 相似文献
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磁场定向控制(FOC)理论是永磁同步电机(PMSM)最常用的控制方法之一。该方法需要电机转子瞬时精确位置,因此限制了其在使用霍尔位置传感器的无刷直流电机(BLDCM)上的应用。为了能够在BLDCM上应用FOC理论,又不增加电机成本,在现有霍尔位置传感器的基础上,提出了一种根据霍尔传感器的输出信号,通过计算前一个扇区平均转速的方法估计转子精确位置。使用MATLAB/Simulink软件对该估算方法进行了仿真,并搭建了以TI 的TMS320F28069 DSP为核心的试验系统,通过自动代码生成技术完成算法的编程,可以较好地应用于BLDCM的控制,在一些应用场合可以代替PMSM从而降低使用成本。 相似文献
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对航空无刷同步电机起动发电系统电动运行的励磁特性进行了理论分析,提出了交直流混合励磁方案,建立了系统的MATLAB/SIMULINK仿真模型。仿真结果表明,主发电机励磁电流平均值随励磁机励磁频率的升高而减小,且主发电机励磁电流脉动率随转速升高有唯一极小值点,该点可作为交直流励磁的切换点。 相似文献