异步电动机定子绕组匝间短路故障检测方法研究

基于多回路数学模型，对异步电动机定子绕组匝间短路故障瞬变过程做了数字仿真，并完成了相关实验。通过分析仿真与实验结果，对各种故障特征量的灵敏度与可靠性进行探讨，指出定子负序视在阻抗是最可靠兼具良好灵敏度的定子绕组匝间短路故障特征量。以此为基础，提出了一种异步电动机定子绕组匝间短路故障检测新方法，该方法以定子负序视在阻抗滤波值作为匝间短路故障特征量，并应用神经网络技术根据电机当前运行参数确定适当的故障检测阈值。实验结果表明，该方法是正确可行的。     

A MODIFIED EQUIVALENT CIRCUIT FOR THREE-PHASE INDUCTION MOTORS WITH BALANCED NONSINUSOIDAL VOLTAGE SOURCE

Abstract

In this paper, the equivalent circuit model of a three-phase induction motor with balanced nonsinusoidal voltage waveform is solved by the experimental test of a 3-phase, 3-hp induction motor with a variable voltage, variable frequency (VVVF) voltage source. The parameters are calculated by analyzing the test results with statistical methods.

The performance of an induction motor with nonsinusoidal voltage source is calculated by the computer simulation based on the circuit model derived. The simulation results are compared with the laboratory test to verify the accuracy of the equivalent circuit model.     

TRANSIENT PERFORMANCE OF A GROUP OF INDUCTION MOTORS

ABSTRACT

The paper develops the non-linear differential equations which describe the transient behaviour of a group of parallel-connected induction motors, either when fed from a stiff supply or when the supply is weak and the machine behaviour is interactive. A digital-computer solution of these equations provides a numerical prediction of the transient currents, voltages, torques and speeds of a laboratory-scale group of motors, in close agreement with experimentally-obtained results.     

电动机节能模糊控制器

为提高感应电动机的运行效率，本文提出了电动机节能模糊控制器的实现策略，设计了电动机调压节能模糊器和调频节能模糊控制器原型。它的基本原理是，在保护负载需求的前提下，通过控制电动机的定子电压或频率，最大限度地减少其输入功率，以实现节电运行。模糊控制器的输入变量是定子电流及其变化率，输出变量是定子电压或与频率对应的ＰＷＭ脉冲序列。本文所提出的节能模糊控制器的特点是成本低，鲁棒性强，模糊推理和ＰＷＭ脉冲序     

EQUIVALENT CIRCUIT ANALYSIS OF SHADED-POLE MOTORS

ABSTRACT

A general procedure for the analysis of shaded-pole motors, based upon rotating field theory, is presented. The analysis allows for as many as three shading coils per pole as well as an arbitrary reluctance-augmented airgap. The procedure is applied to a typical shaded-pole motor and results are compared with experimental values.     

AN ELECTROMECHANICAL NETWORK MODEL FOR FREQUENCY CONTROLLED INDUCTION MOTORS

ABSTRACT

An electromechanical network model valid for small values of slip under steady state and dynamic conditions is given for frequency controlled induction motors. The model has been developed using the perturbation equations in the synchronously rotating reference frame and neglecting stator resistance and stator transients. Bode plots of incremental transfer functions relating speed and load torque as well as speed and stator frequency under constant volts/Hz control mode obtained from the exact and approximate models are compared with those of the electromechanical network model. The usefulness of the model in steady state and dynamic studies is discussed     

基于多回路数学模型的异步电动机内部故障瞬变过程

基于多回路理论,建立了YN接、Y接、D接笼型异步电动机在正常、内部故障(定子绕组匝间短路与转子断条)情况下的多回路数学模型。应用多回路数学模型对电机内部故障瞬变过程进行数字仿真和实验,以此研究电机定子电流及其负序分量、相位对称关系、边频分量的瞬变规律。分析仿真与实验结果表明：由于实际电机本身固有的不对称性,即使其正常运行,也必将在一定程度上体现内部故障特征;某些形式的定子绕组匝间短路故障可能抵消这种不对称性,并削弱(而非强化)定子绕组匝间短路故障特征;实际电机定子电流往往包含包括转子断条故障特征分量在内的多个边频分量,其中某些边频分量可能来源于电机气隙偏心、转子不对中或其他因素。在工程实际中进行电机内部故障检测时,必须密切关注上述规律,以保证故障检测灵敏度与可靠性。     

OPTIMIZATION OF DUAL SPEED INDUCTION MOTORS

ABSTRACT

Design optimization of single-winding dual speed and double-winding dual-speed three phase induction motors is attempted. The choice of independent variables and the specification of the performance requirements for these two types of motors are discussed. The formation of an objective function end the various steps involved in the minimization process are explained. It has been shown that comprehensive computer programs can be developed to design optimum dual speed motors of any pole ratio with any stator coil span and winding connection.     

A NEW PHILOSOPHY FOR SPEED-CHANGE INDUCTION MOTORS

ABSTRACT

A new concept termed ‘phase shift modification’ for the design of two-speed single-winding three-phase induction motors is discussed. Designs are classified based on the chosen phase-spread on the initial and final pole scales. A method for improving the layer factor on the final-pole connection without affecting the winding factor for the initial pole connection is also presented. Although the concept is illustrated with respect to a 8/10 pole-combination it is equally applicable to any other pole-ratio.     

基于随机算法的三相异步电动机全局优化

以效率为目标函数的铸铝转子异步电机全局优化是一种个复杂的非凸、非线性规划问题。首先使用ＴＡＢＵ算法将这一高维问题降维分解并缩步搜索域,一局寻优。验证结果表明,该方法充分了长期积累的经验知识,与单独使用ＴＡＢＵ算法或遗传算法相比,计算量较为合理,结果满意度较高,基本满足了高效电机设计的要求。     

DC BRAKING CHARACTERISTICS OF DOUBLE-SIDED LINEAR INDUCTION MOTORS

ABSTRACT

An analysis of dc braking performance of linear induction motors is presented. Specific phenomena such as longitudinal end-effects and transverse edge-effects are taken into account. Computed results are compared with test results available for the dc braking characteristics of the existing largest double-sided linear induction motor.     

HARMONIC ANALYSIS OF INDUCTION MOTORS WITH STATOR FAULTS

ABSTRACT

In the paper stator faults are analyzed by means of a procedure based on the space-vector theory. The used approach, due to Stepina, allows to consider separately each conductor of every single slot and therefore to take easily into account the winding dissymmetry.

The interactions among the different harmonic fields are studied by starting from the topological structure of windings and the harmonic analysis of the currents and of torque Is carried out.

The method is tested to numerical computations of steady-state currents for an induction machine with different positions of stator short-circuits.

Finally the procedure is validated by using an experimental squirrel cage machine, having stator windings constructed so as to realize different short-circuits.     

无轴承异步电机悬浮子系统独立控制的研究

无轴承异步电机转矩绕组和悬浮绕组的独立控制是该电机实现超高速运转的有效途径。针对这一强耦合的非线性复杂系统，本文研究了一套独立的悬浮绕组控制子系统，其中所需的转矩绕组气隙磁链的幅值和相位可通过独立的电压模型方法辩识得到。这样一来，不仅超高速运转成为可能，而且转矩绕组的控制原则上可采用任意的调速方法，特别是低成本、高可靠性的通用变频器的运用将大大提高无轴承异步电机的实用性。实验证明本文提出的悬浮绕组独立的控制子系统能较好地满足电机径向悬浮的稳、动态性能要求。     

A MATHEMATICAL MODEL OF THREE-PHASE INDUCTION MACHINES

ABSTRACT

A technique for studying the behaviour of three-phase, wound-rotor induction machines under both transient and steady-state conditions is described. It is arranged to cope with both non-sinusoidal winding distributions and non-linear operation of the magnetic paths. Because such conditions prevent simple expressions from being obtained when transformations are made to produce a two-axis equivalent model, the present analysis is based on the actual machine windings. The basic equation. |v| = |z| |i| is solved for each time step after the appropriate values of the elements in the impedance matrix have been determined by examining the magnetic conditions around the air gap periphery.

The results of particular studies are given.     

IMPROVED PERFORMANCE OF HIGH-SPEED SINGLE-SIDED LINEAR INDUCTION MOTORS: A THEORETICAL STUDY

ABSTRACT

It is shown that a high-speed - 80 to 120 m/s - single-sided linear induction motor (SLIM) can perform almost as well as a double-sided one, if the secondary of the SLIM is made up of an aluminum plate mounted on a back-iron consisting of two or three longitudinal ‘solid’ laminations. This feature retains most of the advantages of a SLIM such as compatibility with guideway and low costs of material, mounting and maintenance. Thus, a SLIM, with solid laminations for back-iron, is analyzed including the consequences of the machine topology and physical phenomena. A numerical example is given to compare the results with those for the largest existing double-sided motor.     

TRANSIENT PERFORMANCE OF A GROUP OF INDUCTION MOTORS WITH TERMINAL CAPACITORS FOLLOWING SUPPLY DISCONNECTION

ABSTRACT

In this paper a model representing a group of three-phase induction motors, with terminal power-factor correcting capacitors, following disconnection of the group with its terminal capacitors as one unit from the supply, is derived. From this model the transient behavior of the motors of the group and the interaction between them, following supply disconnection is investigated, and the effect of the terminal capacitors on the transient behavior of each motor of the group, regarding terminal voltage, stator currents, airgap powers, is shown.     

新型软起动最小转矩脉动的控制策略研究

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。     

CONCEPT OF BUILT-IN RELIABILITY IN THE DESIGN OF LARGE INDUCTION MOTORS

ABSTRACT

In recent years, the reliability study of the equipment has been given vital importance alongwith the other studies. In this paper, an attempt is made to construct the reliability model of a large induction motor in order to predict the reliability, with the knowledge of realistic failure data. Since the author is not aware of any failure data, the prediction is based on some realistic failure data. However, in this paper the basic concepts are laid down, to ensure reliability goal of each component in the design stage. It is also emphasised here, the effect of supply conditions, ambient and malfunctioning of accessories in induction motor on its reliability goal. The method of attack is based on Markov model, by judiciously choosing ‘Available’ states and ‘Failed’ states. This method affords better realisation of failure modes and possible decisions to improve the same. The theory of reliability is presented in short, in order to make the ideas presented in this paper, more clear. A numerical example is presented at the end, to elucidate the theory presented here.     

三相异步机不对称稳态运行的矩阵方程

与对称分量法不同，本文用一种新的方法－－等效电流法，来分析三相异步电机不对称稳态运行并推导了一系列关系式，所有公式均用矩阵方程表示，使之适用于计算机分析计算。     

复合实心转子异步电动机的起动特性仿真

本文运用状态变量法和坐标变换理论建立了实心转子异步电动机的稳态和动态特性仿真模型，考察了随转速而变化的实心转子参数对动态特性的影响。用定步长四阶龙格－库塔法对几台个有不同转子外层材料的复合实心转子异步电动机的起动性能进行了数字仿真计算，并进行了测试，计算结果与试验值基本相符。