不对称阻尼绕组凸极同步电机瞬态及超瞬态参数的分析与计算

现代凸极同步电机转子阻尼绕组结构设计比较灵活，除通常对称等节距阻尼绕组外，还有对称不等节距绕组和不对称、但以二极电机为周期循环的阻尼绕组。该文以不对称、但以二极电机为周期循环的阻尼绕组的同步电机模型作为研究对象，对阻尼绕组按实际的网形电路选取回路，从派克方程出发，获得该模型的磁链方程和电压方程，经由dqo变换及一些技巧性处理，导出运算电抗xo(s)和xq(s)，然后经参数辩识，确定电机的直、交轴瞬态电抗和超瞬态电抗以及相应的时间常数。该文方法不但适用于不对称、但以二极电机为周期循环的阻尼绕组，也适用于等节距和不等节距的对称阻尼绕组。该文提供的是计算凸极同步电机暂态参数的一种新方法。     

阻尼绕组结构形式及结构参数对同步电机交－交变频调速系统特性的影响

文中，作者首先比较了交－交变频调速同步电机在具有不同结构的阻尼绕组时的特性差异，接着分析了阻尼绕组电气参数对同步电机交－交变领调速系统性能的影响，最后揭示了阻尼绕组电气参数与结构参数的关系，为这类系统中阻尼绕组的设计提供依据。     

同步电机阻尼绕组设计分析

通过对工程实践中同步电机在阻尼绕组中节距的选择、结构设计的要求等出现的问题进行了总结,提出了同步电机在阻尼绕组设计中重点问题及其解决思路,并给出了具体的计算方法。     

凸极同步电动机双层阻尼绕组设计研究

对凸极同步电动机双层阻尼绕组进行了理论分析,并采用传统和有限元两种计算方法对工程实例进行了验证,提出了凸极同步电机在双层阻尼绕组设计中重要问题的具体解决思路和解决方法。     

同步电机阻尼绕组电流测量方法

实际测量各种运行状态(例如异步运行、瞬变、不对称运行等状态)下同步电机阻尼绕组电流,对于研究同步电机阻尼绕组的作用、研究阻尼绕组电流及其分布、改进阻尼绕组设计等都是十分重要的。但由于结构上的特点,阻尼绕组电流不能用简单的方法直接测取,只能作为一个特殊测量问题来处理。其原因是:(1) 除旋转电枢式同步电机外,测量要在电机的旋转部分上进行,必须附加一套旋转前止变换装置;(2) 阻尼绕组电路不能开断,为了测量阻尼绕组电流,必须设置专用测量元件;(3) 同步电机绕组端部是一个强磁场区,测量元件与引出线必须有良好的屏蔽措施。这里介绍国内外常用的几种测量方法。     

同步电机调相运行动态稳定性及电力系统稳定器的作用分析

针对同步电机调相运行时的动态稳定性能及电力系统稳定器的作用进行了分析,并以单机－无限大系统为例给出了计算结果。研究表明：同步电机调相运行时,主要是阻尼绕组产生的阻尼转矩抑制低频振荡,保持其运行的动态稳定性,而电力系统稳定器不再提供附加的正阻尼。     

凸极同步电机阻尼绕组对定子磁势谐波的阻尼系数

研究带有阻尼绕组的凸极同步电机电磁振动、噪声、参数和电压波形等问题时,必须计及阻尼绕组对气隙磁场的阻尼作用和阻尼绕组附加磁场的影响。本文在忽略阻尼绕组电阻的假定下导出阻尼绕组对定子谐波磁势的阻尼系数和阻尼绕组附加磁势的计算公式。通过计算表明,对于大多数定子反转磁势谐波和许多反转谐波均可忽略电阻的影响。     

阻尼绕组对磁场定向控制交－交变频同步电机动态行为的影响

本文在交－交变频磁场定向控制同步电机调速系统数学模型的基础上，研究了阻尼绕组对交－交变频同步电机动态行为的影响．结果指出．阻尼绕组能有效地抵消动态电枢反应，加快定子电流响应，提高电机的过载能力．从改善系统的动态特性出发，应选择全阻尼结构。     

考虑阻尼绕组约束能量变换器空载电动势波形的分析

电机的阻尼绕组端部联结方式的不同,使得阻尼条中感应涡流的约束不同,引起阻尼绕组电流的分布不同,从而对气隙磁场和空载电动势产生影响.本文提出了场路耦合时步有限元法来计算凸极同步电机空载电动势波形,针对能量变换器样机,进行了考虑不同阻尼绕组约束条件下的空载电动势波形的计算,并对计算结果和实验值进行了比较.结果表明,阻尼绕组约束不同,能量变换器空载电动势谐波含量不同,电动势波形的正弦畸变率也发生一定的变化,精确计算时需要考虑这种变化.     

不均匀负载下同步电机阻尼绕组的强度计算

介绍了同步电机在不均匀负载(起动、制动以及随负载的转速波动)和正常运行时,离心力作用下阻尼绕组的强度计算及考核方法.该方法将负载转矩、同步电机过渡过程以及电机自身的转动惯量综合予以考虑,使阻尼条的受力分析更加准确,具有实际的工程使用意义.     

凸极同步电机小信号运算电感的计算

小信号运算电感数值计算中的问题有:增量磁导率的使用,转子绕组的处理等。本文采用场路耦合法处理转子的阻尼绕组和励磁绕组,既合理地反映了转子的复杂回路,又避免了端部漏磁引起的修正。通过对采用不同磁导率计算的比较,得到了一些具有实际意义的结果。     

抽水蓄能电机调相运行时的动态稳定性能分析

文章针对抽水蓄能电机调相运行时的动态稳定性进行了分析,并以单机－无限大系统为例给出了计算结果。研究表明：抽水蓄能电机调相运行时,主要是阻尼绕组产生的阻尼转矩抑制低频振荡,保持其运行的动态稳定性。     

A calculation method of field current of synchronous machines at sudden short‐circuit

The mutual leakage reactance between D‐axis damper and field windings is ignored in conventional D‐axis equivalent circuits. It has been pointed out, however, that the calculated value of the field current differs considerably from the measured value if this reactance is not taken into account. This is due to the difficulty of determining the physically correct damper winding impedance value. A method of determining the equivalent circuit constants using the mutual leakage reactance has been reported previously, where the D‐axis damper winding time constant is measured from the upper and lower envelopes of field current at sudden three‐phase short‐circuit. Yet there are machines for which the upper and lower envelopes of field current are not readily established, and in this case the method is unsatisfactory. The authors describe a method to accurately identify the equivalent circuit constants taking into account the mutual leakage reactance, using a standstill test with a small‐capacity DC power supply (DC decay testing method). The field current at sudden short‐circuit can be simulated accurately using these equivalent circuit constants. The validity of the proposed method is demonstrated by implementation results on two salient‐pole synchronous machines at the same specifications (one with damper winding, the other without). Furthermore, the dependent relation between the armature leakage reactance and mutual leakage reactance, as well as its influence on the calculation of field transient currents, are made clear. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(3): 61–70, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20113     

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     

阻尼绕组对谐波励磁同步发电机空载谐波电压的影响

利用ANSYS有限元软件自带的APDL编程语言进行二次开发,用二次开发软件对谐波励磁同步发电机空载谐波磁场进行大量有限元计算,应用齿磁通法对电磁场的计算结果进行后处理,得出了谐波绕组空载特性曲线,计算结果与实验结果的比较说明了该方法的正确性。基于该方法,详细分析了阻尼绕组对谐波励磁同步发电机谐波空载特性的影响。     

基于三步隐式Adams法的同步电机阻尼绕组电流计算

提出采用精度更高、绝对稳定域更大的三步隐式Adams法对现有的阻尼绕组电流计算方法(一阶向前差分法,R-K1)进行改进,并分析了初值设置和采样频率对算法的影响,结果表明改进的方法具有对于同步电机阻尼绕组实际电流的更好的跟踪特性。文中以基于PSCAD的IEEE次同步谐振第一标准模型为例,通过仿真验证与对比分析,体现了采用三步隐式Adams法计算阻尼绕组电流的优越性。     

A method of predicting transient constants of synchronous machines

It is difficult to determine the subtransient (transient) reactance and subtransient (transient) short-circuit time constants of medium and large synchronous machines by the sudden three-phase short-circuit test because large-capacity equipment is required. This paper describes a new method of measuring these constants by means of a simple test using a small dc power supply. The key points of this method are as follows. (1) A dc voltage is applied to the armature winding (two terminals with the third one open) of a stationary synchronous machine through a resistance. When the two terminals are closed, the winding is short-circuited and the current in the armature winding decays. The whole process of decaying current is recorded. (2) The value of the transient phenomena of the winding calculated from circuit equations (armature, field winding and damper winding circuits) is compared with actual data, and the unknown equivalent circuit constants are identified by the least squares method. (3) Transient phenomena of the sudden three-phase short-circuit are calculated by the two-reaction theory using identified constants, and, hence, these constants are calculated. The transient constants of synchronous machines obtained by the new method agree closely with the observed values.     

多相双层交流绕组槽比漏磁导的统一算法

本文基于三相同步电机设计,分析了多相对同步电机交流绕组槽比漏磁导的影响,并得出其统一计算公式,可以方便地用于多相同步电机设计和研究.     

The generalized theory of indirect vector control for AC machines

The instantaneous torque produced by an AC machine is controllable when vector control is applied. However, the published papers on vector control deal with either induction machines or synchronous machines. A generalized vector-control theory is developed, considering a generalized AC machine as a salient-pole synchronous machine having three kinds of torque, i.e., the field torque, the reluctance torque, and the induction torque. The theory can be extended to the AC machines producing a voluntarily combined torque among the three. The experimental system consisted of applying the generalized vector control theory to a nonsalient-pole synchronous machine with damper winding. It was verified experimentally that the instantaneous torque was controllable, not only in synchronous or induction-machine operation, but also in the transient state between the synchronous-machine operation and induction-machine operation, without any change of the control circuit     

3 MW同步发电机阻尼绕组设计与超瞬态电抗性能验证

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。