凸极同步电机饱和同步电抗的数值计算

本文先讨论影响同步电机稳态电抗饱和值的因素,然后用文献提出的有长度折算的二维有限元分析计算了在零功率因数负载(超前和滞后)、纯交轴饱和、额定运行三种情况下直轴饱和同步电抗x_d的变化曲线,纯交轴饱和、额定运行两种情况下交轴饱和同步电抗x_q的变化曲线,以及额定运行时交、直轴之间的耦合电抗x_(dq)、x(dq)的变化曲线.     

凸极同步发电机运算电抗频率特性及饱和瞬态电抗的有限元计算

本文首先采用二维涡流场的有限元解法计算了一台大型(无阻尼绕组)水轮发电机直轴运算电抗的频率特性,其中通过在有限元方程中加约束条件使励磁绕组每匝感应涡流相等.然后通过令频率为无穷大和作定、转子端部修正后确定直轴瞬态电抗的不饱和值,最后计算了在不同短路电流下发生三相突然短路时的饱和值及饱和系数,绘制了相应的曲线.     

混合励磁永磁发电机电抗参数研究

针对混合励磁永磁同步发电机的特殊磁路结构,介绍了一种用以计算交、直轴电抗参数的计算方法。利用该方法计算了1台7.5 kW、1 500 r/min的混合励磁永磁发电机的交轴电抗和直轴电抗,利用试验测试电抗参数对计算结果进行了验证。结果显示,所提混合励磁永磁同步发电机交、直轴电抗参数计算方法计算精度较高,为混合励磁永磁同步发电机结构参数和电抗参数的合理设计提供了帮助。     

永磁同步电动机电磁参数的有限元分析

建立了永磁同步电动机漏磁系数和交直轴同步电抗的场路结合数学模型,并利用Maxwell 2D软件的参数化分析工具对永磁同步电动机的空载漏磁系数和交直轴同步电抗进行了计算,得出了这些参数随电机结构参数的变化曲线.在此基础上,总结了永磁同步电动机电抗参数的变化规律,为永磁同步电动机的优化设计提供了一种非常直观有效的方法.     

永磁同步电动机电抗参数研究

永磁同步电动机电抗参数是电机性能分析和优化设计的重要依据.由于永磁同步电动机转子磁路结构多种多样,与普通同步电机有很大差别,电抗参数用现有计算方法难以计算准确,不仅导致延长研制过程、加大研制费用,而且使设计优化和性能仿真缺乏科学依据.本文利用ANSOFT软件对永磁同步电动机的交、直轴电枢反应电抗参数进行计算,计算结果与试验测试结果吻合较好,在此基础上总结出永磁同步电动机电抗参数的变化规律,为永磁同步电动机设计提供了依据.     

低电压调整率交流永磁发电机的设计

根据内置式永磁同步发电机带纯电阻负载时,取得低电压调整率的条件,提出了设计低电压调整率交流永磁同步发电机的方法,并场路结合进行计算,设计了一台低电压调整率的交流永磁发电机.通过有限元计算负载场,得到了电枢反应电抗的饱和值和电压调整率,并与相量法得到的电压调整率进行了比较.分析结果表明本文的设计和计算方法是正确有效的.     

基于ANSYS的永磁同步电机场路结合电磁设计方法

提出了一种基于ANSYS Maxwell 2D的永磁同步电机(PMSM)场路结合电磁设计方法。通过ANSYS Maxwell 2D软件分析计算得出PMSM 2D理想电机模型的空载励磁电动势、负载时的励磁电动势、直轴同步电抗和交轴同步电抗参数,并以此修正基于电路和磁路的电磁设计程序中用来计算空载励磁电动势、负载时的励磁电动势、直轴同步电抗和交轴同步电抗参数的校正系数,从而使得PMSM的设计结果更加准确。通过该方法设计了PMSM并进行了试验。试验结果验证了该设计方法的正确性。     

突然短路试验测定水轮发电机的饱和电抗值

三相突然短路试验是测定水轮发电机瞬态参数的常规试验方法,但在水电站现场,在额定电压下进行试验存在一定安全风险,难以直接测定饱和电抗值。有关研究表明,可以采用不同电压下测定的电抗非饱和值,推算饱和电抗值。本文对一水轮发电机,开展了在多个空载电压下的三相突然短路现场试验,根据直接测定的不同电压下的多个非饱和电抗值,采用线性最小二乘法外推得出了水轮发电机直轴瞬态电抗和超瞬态电抗的饱和值。试验结果表明,计算得到的饱和电抗值与设计值偏差在10%以内,满足相关容差要求。该方法在水电站现场测定水轮发电机直轴瞬态和超瞬态电抗饱和值方面具有可行性,能够满足工程上的测试需要,值得行业借鉴。     

三段圆弧极靴大型凸极同步电机的稳态电抗计算

介绍了用电磁公式和有限元两种方法计算具有３段圆弧极靴磁极的大型凸极同步电机稳态电抗,并以北京十三陵抽水蓄能电机为例进行了实算。首先,通过直轴和交轴磁场和磁路的计算确定同步抗ｘｄ和ｘｑ;而后通过有限元计算;从负荷运行状态下的磁场中获得同步电抗;最后对不同方法的结果进行了对比分析,并对直,交轴的耦合电抗也进行了分析计算。     

轨道交通用永磁同步牵引电机电抗参数的有限元分析

永磁同步牵引电机具有体积小、功率密度大、过载能力强、效率和功率因数高等特点,而电抗参数对永磁同步牵引电机的设计以及电机运行时平衡恒转矩转折速度点与弱磁恒功率最高速度点的性能有较大影响。本文利用Ansoft有限元分析软件对永磁同步电动机的交直轴同步电抗进行了计算,得出了交直轴电抗参数随电机参数的变化曲线,并分析了电机参数对电抗参数的影响。     

Analysis of turbine generator steady-state reactances for load conditions

This paper describes variations of turbine generator steady-state reactances for load conditions. When the turbine generator is of small size, magnetic saturation of the stator and rotor core is a problem. Therefore, it is important to understand the variations of the reactances for load conditions. The reactances of a 592-MVA turbine generator are calculated with d- and q-axis equations considering magnetic saturation and two-dimensional numerical magnetic field analysis. The results are as follows. (1) The equivalent synchronous reactances considering cross-magnetizing are smaller than the original synchronous reactances for load conditions. (2) Numerical values of the d- and q-axis mutual reactance and the field and q-axis mutual reactance are at their maximum when the d-axis linkage flux is nearly equal to the q-axis linkage flux under constant voltage. (3) The d-axis synchronous reactance drops with increasing reactive power under constant voltage and active power, but the q-axis synchronous reactance increases. (4) The variation of the equivalent d-axis synchronous reactance with increasing reactive power is similar to that of the d-axis synchronous reactance, but the variation of the equivalent q-axis synchronous reactance is different from that of the q-axis synchronous reactance. © 1998 Scripta Technica. Electr Eng Jpn, 123(3): 73–83, 1998     

汽轮发电机饱和同步电抗的波动

本文以６００ＭＷ汽轮机电机为例,用有限元法计算了不同瞬时的饱和同步电抗,阐明了受饱和影响时同步电抗的波动情况。     

六相同步发电机的稳态电磁参数

从Park方程的基本原理出发,建立了六相同步发电机的基本方程,得到了六相同步发电机的d轴等值电路和q轴等值电路。等值电路中的综合互感抗体现了六相同步发电机2个Y之间的磁耦作用,由电枢反应电抗和综合漏互感抗2部分组成。通过对六相同步发电机单Y运行(另一Y开路)和双Y运行的分析,得出双Y运行同步电抗为2倍的单Y运行同步电抗与单Y自漏抗之差。以空载短路试验的实例,测试了六相同步发电机特性曲线,以及d轴同步电抗、自漏抗和短路比。从电磁理论分析和实际运行特性2方面,验证了六相同步发电机的稳态电磁参数。     

一种高性能调速永磁同步电动机的设计

运用简化的等效磁路与同步电动机相量图相结合的方法,提出了表面式磁钢结构永磁同步电动机设计思路,并给出了设计程序流程图。对设计过程中两个重要参数———定子漏抗和电枢反应电抗进行了深入的分析计算,并用一台27.5kW永磁同步电动机的试验数据验证了该方法的可行性。     

考虑磁路饱和的永磁式同步电机计算

介绍一种考虑到磁路饱和的永磁同步电机转矩和电抗的计算方法。该方法利用有限元法对二维磁场进行数值解析，并给出包含正交磁化现象影响的d、q轴方程式。通过改变转子的位置计算水磁同步电动机的转矩和电抗，给出了转矩和电抗随转子位置变化规律的曲线。实验结果验证了其计算方法的正确性。     

周向双层绕组永磁式发电机电抗参数的计算

电枢反应电抗参数的准确计算对电机的性能有很重要的影响,但现有的方法很难考虑交、直轴的耦合情况,而不能对电抗参数进行较为准确的计算。在ANSYS软件的辅助下,通过修改软磁材料的相对磁导率对周向双层绕组永磁式发电机的电抗参数进行了计算,结果与实验值很接近,证明了该方法的准确性,也为提高电抗参数的计算精度做好了准备。     

考虑磁饱和影响的同步发电机励磁电流计算

在考虑同步发电机磁路饱和效应的基础上,提出了发电机励磁电流计算的数学模型.该模型涉及发电机的空载特性曲线、保梯电抗和磁路磁链方程,计算过程比较简便、实用.对于不计饱和特性、直接采用饱和电抗以及采用定子漏抗替代保梯电抗的三种情况分别进行了励磁电流计算,以发电机V形曲线的形式比较了该模型与这三种情况下的计算结果差异,经多台发电机励磁电流的计算和实际测试,验证了该模型的有效性和实用性.     

A study of the variation of synchronous machine parameters due to saturation: a numerical approach

This paper shows the variation of the fundamental parameters of synchronous machine two-axis equivalent circuits due to magnetic saturation. The different magnetic states of the machine are obtained using finite-element magnetostatic solutions. This way the permeability patterns of the saturable parts of the machine can be stored and used in a specially designed finite-element program that outputs the standstill frequency response (SSFR) of the machine. A hybrid genetic algorithm, capable of finding global extrema is then applied to obtain the parameters of two equivalent circuit structures for the d-axis. The process is repeated for each magnetic state, so that the variation of parameters can be seen. The magnetic states of the machine are validated by comparing the measured open-circuit characteristic with the one calculated from the finite-element model. In order to validate the d-axis equivalent circuit parameters identified, they have been adopted in the simulation of a synchronous machine short-circuit and the results obtained have been compared to those calculated by a transient finite-element program.     

TCSC抑制次同步谐振的机理分析

基于对TCSC次同步频率等效阻抗特性的研究，分析了TCSC次同步频率等效电阻和等效电抗对抑制次同步谐振（SSR）的不同作用。发现系统中SSR的抑制主要取决于TCSC的次同步频率等效电抗特性，而TCSC的次同步频率等效电阻对SSR的抑制本质上是一个能量转换过程，它只能在一定程度上削弱SSR，不可能彻底消除SSR。     

A calculation method of equivalent circuit constants with mutual leakage reactance on synchronous machine with damper winding

The mutual leakage reactance between the d‐axis damper and field windings is ignored in the conventional d‐axis equivalent circuit. It has been pointed out that the calculated value of the field transient current differs considerably from the measured value when this reactance is not taken into account. A method to determine this reactance has been reported previously, but this method has problems concerning measurement precision. The authors have previously presented a calculation method for equivalent circuits, adapting a DC decay testing method, using two synchronous machines of the same specifications (one with damper winding, the other without). Yet, this method is not practical because of the use of two machines. This paper presents a calculation method for equivalent circuit constants taking into account the mutual leakage reactance to accurately represent the field transient current using a single machine. The proposed method determines equivalent circuit constants by calculating the physically correct d‐axis transient reactance from the operational impedances when the field winding is shorted and when the field winding is shorted with an external resistance. The validity of the proposed method is demonstrated by comparing the measured values with the calculated values of field and armature currents at sudden three‐phase short‐circuit. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(2): 71–78, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20891