共查询到20条相似文献,搜索用时 46 毫秒
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基于电机定子绕组发生匝间短路故障时阻抗参数的变化,根据匝间短路故障程度与定子阻抗参数之间的关系,基于有限元方法,提出了一种电机定子绕组匝间短路故障建模方法,该模型可以用于分析电机匝间短路故障研究。运用有限元分析软件对电机在正常运行和不同程度故障情况下的内部磁场进行了模拟,验证了运用有限元法进行电机内部故障仿真分析的可行性。 相似文献
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介绍了珠海发电厂2#发电机转子匝间短路故障诊断分析过程及故障处理方法,通过具体事例分析发电机转子匝间短路故障诊断手段在实际中的应用,为国内同类型机组故障处理提供很好的借鉴. 相似文献
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提出了一种在干式变压器在线运行条件下进行低严重度匝间故障的检测方法,所提出的方法仅需变压器外支处的磁芯漏磁通的基本分量。接着根据所提出的分析模型进行理论分析,并在10 kVA变压器样机上进行实验验证,以评估所提出的方法在不同故障严重程度下的性能。最后采用制造的样机健康监测装置评估了所提出方法的实时故障检测能力,结果表明:在3个基本周期内可以检测到150匝中低至2匝的匝间故障,该方法不受负载和电源电压不平衡条件的影响,检测能力与基于差分负序电流的传统技术相当,但减少了三相三绕组变压器所需传感器总成本的93%。 相似文献
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A transient model for an induction machine with stator winding turn faults on a single phase is derived using reference frame transformation theory. The negative sequence component and the 3rd harmonic are often considered as accurate indicators. However, small unbalance in the supply voltage and/or in the machine structure that exists in any real system engenders the same harmonics components. In this case, it is too difficult to distinguish between the current harmonics due to the supply voltage and those originated by inter-turn short-circuit faults. For that, to have the correct diagnosis and to increase the sensitivity and the reliability of the diagnostic system, it is crucial to provide the relationship between the inter-turn short-circuits in the stator winding and the supply voltage imbalance through an accurate mathematical model and via a series of experimental essays. 相似文献
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为了更有效地辨识永磁风力发电机组的故障特征,从叶轮扫掠面内的实际风况出发,综合考虑风剪切、塔影效应产生的风速时空分布差异,并研究该差异对永磁风力发电机组故障特征的影响。首先介绍考虑风速时空分布差异后的风速模型(等效风速模型),然后基于该模型对永磁风力发电机组常见的电气和机械故障特性进行理论分析,分别推导得出考虑风速时空分布后绕组不对称故障、叶轮不平衡故障以及这2种故障复合作用下的定子电流表达式;最后利用Matlab/Simulink平台进行仿真验证。研究结果表明,与现有的基于轮毂处平均风速的故障特征相比,考虑风速时空分布差异后,永磁风力发电机绕组不对称故障特征中含有3kP(k为整数,P为叶轮转频)为主的调制频率;叶轮不平衡故障特征频率除P和3kP外,还出现了P与3kP的耦合调制;复合故障下频率成分会更复杂。 相似文献
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针对矿用运输设备皮带输送机永磁同步电机的现状,分析了矢量控制、直接转矩控制、自适应控制、滑模变控制和预测控制5种调速系统定向形式的优缺点.同时,利用MATLAB仿真模拟软件对永磁同步电机系统进行了仿真模拟,得出前馈解耦控制转速响应下的转速反应更加灵敏,解决了PI控制转速响应下转矩脉动问题,系统的稳定性得到了提高.综合利... 相似文献
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常规变速控制系统的精度不高,变换器晶闸管开关动作产生的高频纹波较大,为此提出一种基于卡尔曼滤波的反步控制方法。文章通过分析波浪能提取装置的受力及幅频特性,获取了波浪能转化效率最大化的控制条件,并搭建了一套基于卡尔曼滤波的波浪发电反步最优功率控制系统。通过仿真研究了3种控制方法的控制精度和有效性,仿真结果表明:低通滤波反步法存在相位延迟,不能满足最大功率捕获策略的相位条件,影响系统的最终有功功率输出;反步法的跟踪误差较大,导致系统输出的有功功率较低;卡尔曼滤波反步法的动态性能较好,跟踪电流的波形振幅较小,能保证系统全局收敛,在电机速度方向、幅值和频率突变的情况下,仍能快速准确跟踪给定信号,鲁棒性和抗干扰能力更好。 相似文献
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Rogerio Diogne de So uza e Silva Maria Emilia de Lima Tostes 《能源与动力工程:英文版》2014,(9):1620-1632
The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focuses on the importance of implementing minimum efficiency standards in Brazil and elsewhere and presents the state of the art in domestic and international legislation and standards pertaining to induction motors. It also covers advancements in motor technology, by means of an analysis of motors currently on the market, and trends in said technology, with particular emphasis on the search for new materials for permanent magnet manufacturing. The results of experimental testing of a permanent-magnet motor and a premium-efficiency induction motor are presented and discussed, with the objective of contributing to definition of the IE4 (Efficiency Level from International Electrotechnical Commission) standard and to the goal-oriented Brazilian efficiency program. The present article described the results of experimental testing with an induction motor and a line-start permanent-magnet motor and concluded that permanent-magnet motors are superior in performance to induction motors at loads between half and full, with an efficiency advantage of up to 6.7%. However, in applications with wide variations in load, with motor operation below half load, use of permanent-magnet motors is not economically feasible, as the current cost of these motors exceeds that of induction motors. Another relevant finding concerns the current harmonic distortion observed during testing. The tested permanent-magnet motor exhibited a distortion of up to 13.5%, exceeding Institute of Electrical and Electronics Engineers Standard 519/1992 recommended limits. This behavior must be clearly specified and taken into account by future standards that define the super premium class, lest the impact of harmonic distortion prove to be detrimental to industries that adopt these motors for their processes. 相似文献
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分析直驱永磁同步风力发电机组(DDPMSG)在电网故障情况下的低电压运行特性,提出一种综合控制策略,包括通过变桨距控制实现最大风能追踪;控制发电机电磁功率以控制直流链及电网侧逆变器的功率;利用发电机侧功率控制网侧变流器的电流,实现直流链电压的稳定,以提高直驱永磁同步风力发电机组的低电压穿越能力,维持所并电网的运行稳定性。运用仿真分析软件PSCAD/EMTDC建立DDPMSG及其控制策略的仿真模型,仿真结果验证了所提策略的有效性和可行性。 相似文献
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本文基于飞轮三相永磁同步电机的特性,研究影响飞轮电机控制性能的干扰因素并对其特性进行分析。首先建立动基座条件下飞轮转子的动力学模型,在此基础上对影响电机性能的内外多源干扰进行建模和特性分析,给出详细的干扰模型以及所包含的结构类型。针对干扰所必需的输入参数,设计并实现了飞轮干扰状态的监测系统,获取飞轮实时转速、磁偏转角和基座振动等信息。最后,给出磁悬浮储能飞轮系统实验装置和飞轮参数,为飞轮电机干扰特性验证和干扰抑制方法提供必要基础。 相似文献