三相异步电机在单相电源供电时稳态运行性能的分析和计算

基于分析和单相电机稳态运行的等效电流法。结合近代电路理论中网络图论的有关内容,推导了三角形接法三相异步电机在单相电源供电时,以矩阵形式表示的性能计算公式。将计算值和实验值进行比较的结果表明,两者是比较接近的。     

A COMPANION CIRCUIT MODEL OF INDUCTION MOTORS

ABSTRACT

The theory of a companion circuit model of the induction motor is presented. The model comprises an independent current source in parallel with a constant resistance. Accuracy of problem solutions is the same as that obtained from conventional models, but the time of solution is much shorter. This stems from the combined consideration given to the problem formulation and its solution. A companion circuit model can include extra sets of machine coils such as those needed to represent deep-bar effects. Conventional motor models are adequate for single-machine, transient studies. It is for multi-machine studies that the companion circuit concept provides advantages for formulation and solution.     

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.     

感应电动机暂态电压失稳的定量分析

用时域仿真重现了感应电动机负荷引起的暂态电压失稳现象，进一步改进了感应电动机暂态电压稳定的判据，以便尽早地中止仿真过程；还提出了暂态电压稳定裕度的概念和定义，直接求取与暂态电压稳定相应的故障临界切除时间，以及与给定故障切除时间相应的极限动态负荷。算法的有效性和强壮性华中系统、浙江系统和新英格兰系统中得到了验证。     

复杂电网任一线路的双端电源等值电路

本文导出了复杂电力网络中任一线路的双端电源等值电路，具有精确、快速、算法统一等特点，适用于线路故障及继电保护工况的仿真分析计算。     

A PHENOMENA THAT CAUSES MOST SEVERE TRANSIENTS IN THREE-PHASE INDUCTION MOTORS

ABSTRACT

The dynamical behaviour of a 3-phase induction motor supplied through a distribution transformer and during starting period, subjected to a very short time supply disturbance from the primary side of the transformer, while the secondary side is still connected to the machine, has been studied. The analysis has been made by simulating the machine in time domain by using traditional d-q model, including the effect of transformer secondary vinding impedance during the disturbance period. To verify the accuracy of the digital model, the normal starting transient torque-time pattern under free acceleration is computed and compared with the previously measured results. The transient torque-time, speed-time and current-time patterns of two different machines are computed for the phenomenon under investigation and are compared with their counterparts resulting from starting under free acceleration. Also the effect of the supply disturbance time duration on the transient torque peak has been studied. It was found that the phenomenan under investigation results in the most severe transients compared to all the other types of transient phenomenons that are reported in earlier investigations.     

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.     

基于非线性解耦控制的三相电压型SPWM逆变器

该文针对变速风力发电机组系统所用的三相电压型SPWM逆变器，采用非线性变换和非线性反馈理论，建立了三相电压型PWM逆变器非线性数学模型，推导出其反馈线性化方程，从而得出三相电压型PWM逆变器有功电流和无功电流的解耦控制策略。仿真和实验结果表明，该控制策略能较好地实现三相电压型PWM逆变器的解耦控制，具有较好的动态特性和较强的鲁棒性，能够提高变速风力发电机组供电质量。     

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。     

双定子感应电动机等效电路分析

首先引入旋转等效的概念,将双定子感应电机两个定子之间的相对旋转,看成定子不动,而转子对应部分扭转了一个角度α,又通过引入“相拉折算”的概念,将两个定子之间旋转角的变化,等效为转子相绕组有效匝数的变化,于是能够进行绕组折算,得到折算后的基本方程式,进而导出与常规感应电机相似的“Ｔ”形和“Г”形等效电路。     

变频调速异步电机的优化设计

随着变频调速技术的发展，异步电机在工业传动领域中的应用越来越广泛。传统的异步电机设计方法已经不适应变频调速异步电机的设计要求。传统电机的设计重点在于额定点效率、功率因数、最大转矩、起动转矩、起动电流、运行温升和价格等指标。而变频调速电机的设计重点是在调速范围内的效率、功率因数、温升，以及动态响应性能等。本文根据变频调速集成系统的特点，提出具有针对性的变频调速电机优化设计策略。该策略具有以下几个特点：①采用自适应设计模型；②针对变频器供电的谐波影响分析模型；③采用最优滑差控制和面向系统的优化设计方法。利用该优化设计方法，使得变频调速异步电机更加高效节能。     

带多重逆变器的STATCOM变压器系统等效短路阻抗

给出了带多重逆变器的静止无功发生器的变压器系统等效短路阻抗的定义,阐述了该地静止无功发生器性能的影响,提出了采用分裂变压器的优点。仿真试验表明了等效短路阻抗对静止无功发生器中逆变器流过的电流谐波的影响,为在设计中正确选择等效短路阻抗提供了依据。     

GENERALIZED THEORY FOR THE PERFORMANCE OF THREE-PHASE INDUCTION MOTOR WITH STAR-DELTA WINDING

Abstract

A theory has been developed for the performance of three-phase induction motor with star-delta stator winding. Space harmonics of delta and star components of the winding and their space-phase displacements have been taken into account in the analysis. A general computer program has been developed incorporating the new theory for evaluation of performance. Predictions of performance have been verified by tests on a few three-phase squirrel-cage induction motors with star-delta stator connections.     

电压静态稳定的等效电距离法

电力系统电压静态稳定问题主要解决弱节点的确定和临界状态及其稳定裕度的求取。本文基于静态等值的思想,提出了一种利用等效电距离来确定电力系统弱节点及其临界电压和稳定裕度的方法。该方法物理意义明确,计算速度快。     

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。     

无电网电压传感器三相PWM整流器虚拟电网磁链定向矢量控制研究

电压型三相PWM整流器与变频器供电三相交流电机的定子电路有很大的相似性,采用类似于交流电机磁链观测的方法构造出虚拟的电网磁链矢量,作为PWM整流器矢量控制中的定向矢量,可以达到取消交流侧电网电压传感器、降低PWM整流器硬件成本的目的.准确观测虚拟电网磁链是PWM整流器虚拟电网磁链定向无电压传感器运行的关键.与同步电机磁链观测相似,虚拟电网磁链的观测也存在初始值的问题.不带初始磁链估计的观测器会导致PWM整流器在起动过程中产生很大电流冲击甚至无法起动.为了解决这一问题,该文通过深入分析虚拟电网磁链的特点,提出了一种新的带初值估计的虚拟电网磁链的观测方法.仿真和实验结果验证了所提出观测方法的有效性和无电网电压传感器条件下,三相电压型PWM整流器虚拟电网磁链定向矢量控制运行的良好动、静态特性.     

CIRCUIT MODELS FOR POLYPHASE INDUCTION MACHINES

ABSTRACT

For many years, induction machines operating in the balanced steady state have been represented for analysis by the conventional “T” form of equivalent circuit. Simplification of this circuit to expedite analysis has normally involved approximation This paper presents a number oE simplified equivalent circuits which preserve the accuracy of the “T” circuit and to some extent improve on it by more appropriate representation of saturation and core loss. Experimental confirmation of this improvement is included. The new circuits are denoted as “T” and “inverse-T” because of their inductance configuration.     

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。     

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.     

三相异步电动机同轴度的探索

阐述如何通过结构设计与工艺装备来控制和保证三相异步电动机定子与转子的同轴度。