MODELING OF SYNCHRONOUS MACHINE DAMPER CIRCUITS

ABSTRACT

This paper deals with the modelling of synchronous machine damper circuits, Anterior approaches based on the equivalent circuits fl,8j, have determined experimentally the machine time constants. Nevertheless, they don't have access to real parameters of the damper circuits. We study the case of a salient pole synchronous machine which contains sii damper bars by pole. We have considered the case of bipolar machine. However the proposed method can be generalized for multipolar machines. For that, we use the classical method of static experiments. Referring to a d-q frame, the model of the machine according to the d-axis is a twelfth order system and an eleventh order system in the q one. Taking into account geometrical properties of the rotor, we have found that the state matrix of the machine is analytically reduced to a fifth order in the d-axis and to a third order in the q-axis. Moreover, an eventual reduction of the obtained models is verified by a simulation of a numerical example. As a result, the state matrix becomes a second order one in both axes. Once the reduction is done, and as a typical application of the proposed method, we determine the classical parameters of our synchronous machine.     

EFFECT OF SEQUENTIAL 3-PH. FAULT ON SYNCHRONOUS MACHINE FIELD TRANSIENTS

ABSTRACT

In a synchronous machine with rectifier excitation, large reverse voltage may be induced across the field when following a disturbance, the field current tends to flow in the negative direction and is blocked by the rectifier. In this paper the effect of a sequential fault, in which subsequent to a line-to-line fault, a 3-ph. fault occurs after a small time delay, on the magnitude and duration of the field current in the reverse direction has been analysed. Investigations show that the sequential fault in this respect may be more unfavourable compared to line-to-line or simple 3-ph. faults.     

SYNCHRONOUS STARTING OF SYNCHRONOUS MACHINE

ABSTRACT

Synchronous starting is one of the methods for starting large synchronous motors by small synchronous generators. The equations for Concordia's interlocked generator-motor block logic for synchronous starting are derived in detail. The equations for software implementation including saturation and motor friction torque are presented. Alternative procedure, to overcome numerical differentiation in motor equations, is suggested. Simulation results based on Software developed are given.     

同步电机温度场数值计算与分析

应用电机温度场的数值计算方法，对同步电机定、转子中的温度场分布作了分析，给出了额定工况下定子、转子铁心和定子、转子绕组中的温度场分布图。文中还对不同条件下转子区域的温度场分布作了研究，结果表明，采用励磁绕组直接绕在极身上的整圆冲片式转子取代分离式结构转子，对降低电机中的温升是有益的。     

同步检测法的改进及其在三相不对称无功补偿中的应用

电力有源滤波器能动态补偿不对称三相电路中的谐波分量、不对称电流分量及无功电流分量,为此需快速、准确地检测出这些电流分量。该文对传统的电流同步检测法进行了改进使其能实时检测出不对称三相电路中的谐波电流分量、不对称电流分量及无功电流分量之和,并将其在于三相冰对称无功补偿。理论推导和数字仿真验证了该文思想的正确性。     

通用瞬时功率理论在三相不平衡负荷补偿中的应用

该文运用通用瞬时功率理论对三相不平衡负荷的补偿进行了详细的分析。文中从改变三角形补偿网络中的环流，可以改变补偿网络中各相的功率分布而不影响各相补偿电流的大小这一角度出发，得出了只利用无功元件就能够完全补偿三相不平衡负荷的结论，进一步证实了通用瞬时功率理论在三相间进行功率分布的优化分配这一思想的合理性；提出了利用相间存在耦合的电抗器网络对三相不平衡负荷进行补偿的方法。通过改变该补偿网络中各相的自感及三相电抗间的耦合系数，可以改变三相间的瞬时能量分布，从而使三相不平衡负荷趋于平衡。文中的算例验证了这一方法的合理性。与传统的TSC TCR的方法相比，该文所提方法具有设备简单的优点。     

ANALYSIS OF THE INTERFERENCE SYNCHRONOUS MACHINE

ABSTRACT

Interference synchronous machines operate at different speeds of the fundamental air gap field and of the rotor, because the fundamental permeance wave is produced by interference of open stator and rotor slots the numbers of which being slightly different. In the literature different names are used for this remarkable electrical machine (“Synchronous inductor motor”, “Vernier reluctance motor”). Interference synchronous machines are used as homopolar frequency generators with an axial field coil, as continuous running reluctance motors and as single- or double, - stack step motors with an axial permanent magnet.

In this paper the field of the interference synchronous machine is analysed by field wave theory. Speed,phase angle and length of the largest field waves reveal how synchronous and cogging torques are produced. Voltage and torque equations are derived by axis theory from the simplest model that is possible with five rotor teeth. The theory is applied on a fifty rotor teeth double-stack step motor. The inductances are determined by a difference method field calculation. The torque of the motor is then calculated and compared with measured values.     

网孔等值法在电力系统短路电流计算中的应用

本文阐述了网孔等值电路法在短路电流计算中的应用，推导的计算公式不仅对接有电力负荷，并联电抗器与并联电容器适用，而且在发电机的电势不等时也同样适用，算例对不同性质的计算结果进行了分析。     

同步电机的励磁调节器

同步电机的自动励磁调节器 (以下简称ＡＥＲ )是电力系统最主要的自动装置之一 ,它在很多方面影响电力系统的运行。同时 ,ＡＥＲ也是较难掌握的一种自动装置 ,因其涉及到的理论问题较多 ,包括电力系统的理论和自动控制原理。另外 ,ＡＥＲ的品种繁多 ,目前在我国有不少ＡＥＲ系统或其部件运行不正常 ,甚至不能投入使用。这说明对它们不充分了解 ,故难于在实际工作中发挥其作用。广义上讲 ,属于继电动作方式的强行励磁装置也是一种自动励磁调节器 ,但在此所指的ＡＥＲ是按反馈方式工作的闭环控制励磁调节器。在此不是对ＡＥＲ的工作原理作一般…     

同步电机瞬变参数的测量

本文对基于数据采集瞳的同步电机瞬变参数测试系统进行研究，分析同步电机三相突然短路中电机的暂上应的数学模型；并研制同步电机三相突然短路瞬变参数测试系统，对系统的构成，测试方法，数据处理均进行了介绍，最后给出测试实例。     

COMMUTATION TRANSIENTS IN SELF-CONTROLLED SYNCHRONOUS MACHINES CONNECTED TO D.C. NETWORKS

ABSTRACT

In this paper the commutation phenomenon in a synchronous machine (generator or motor) associated with a thyristor bridge is studied. The transient analysis of the different currents in the different windings is done for a salient pole synchronous machine with damper windings. The different expressions are given in terms of the classical machine reactances and time constants which can be directly measured or furnished by the manufacturer. Comparison between theoretical and practical results are given.     

3/12相双绕组发电机交直流同时突然短路研究

根据3／12相双绕组发电机的基本磁链和电压方程以及等效电路，该文用解析分析和电路模型仿真两种方法详细研究了交直流同时突然短路的过渡过程，得出了定转子短路时间常数和交流侧短路电流的完整表达式，通过适当的近似，进一步给出了适合工程应用的交流侧短路电流的近似和简明表达式以及直流侧最大短路电流的估算公式。另外，还研究了线路电阻对短路电流的影响，结果表明：在分析和测试交直流同时突然短路时，线路电阻，尤其是直流侧线路电阻必须考虑，仿真和实验验证了该文所得数学模型及分析方法的准确性。     

A NOVEL FORM OF SYNCHRONOUS MACHINE EXCITATION

ABSTRACT

A machine is described which utilises the flux pulsations caused by stator slotting to produce a rotor excitation current which can react with the main flux wave to develop synchronous torque. This attractive possibility could result in a brushless, self-excited, synchronous motor, without the requirement of an exciter, and putting to good use what is usually regarded as a source of parasitic loss. The paper presents the performance characteristics and results of tests on a prototype. Methods of calculation of behaviour are presented which could be used to investigate the commercial viability     

网孔等值法在短路电流计算中的应用

阐述了网孔等值电路法在短路电流计算中的应用,推导的计算公式不仅对接有电力负荷、并 联电抗器和( 或)并联电容器的网络适用,在发电机的电势各不相等时也同样适用。算例对不 同负荷性质的计算结果进行 了分析。     

同步发电机励磁非线性预测控制

介绍了一种新的非线性控制器设计方法,使用预测控制理论对非线性系统工将这种方法应用于单机－无穷大系统励磁控制,得到了一了以有功功率,角速率和机端电压作为变量的非线性系统的控制规律,仿真结果表明：该方法既能改善功能稳定性,又能改善发电机端电压的动态特比目前认为较好的微分几何等方法更有效,更实用。     

无刷励磁同步发电机旋转硅整流管故障监测电路的设计与应用

在相复励旋硅式无刷同步励磁电机中，如果在正常运行过程中出现硅整流管开路或短路的故障，必将危及到发电机组的运行。本文提出了一种在线监测旋转硅整流管的方法和设计出监测电路，当硅整流管开路时能发出信号，在短路时能迅速解列发电机，以维护机组的安全。     

NEW DEVELOPMENT OF TORQUE ANALYSIS OF SYNCHRONOUS MACHINE

ABSTRACT

By using a multi-loop model, a new technique for analysing the torque of a synchronous machine is presented in this paper. The electro-magnetic torque of the machine which is very difficult to calculate in some operation conditions by other methods, can be obtained from the inductances of the machine and the currents of every loop of the machine, then the average torque and the pulse torque by Fast Fourier Technique. Comparing the results obtained by the new technique with an established method, the new method is justified.     

无刷励磁同步发电机旋转硅整流管故障监测电路的设计与应用

在相复励旋硅式无刷同步励磁电机中,如果在正常运行过程中出现硅整流管开路或短路的故障,必将危及到发电机组的运行。本文提出了一种在线监测旋转硅整流管的方法和设计出监测电路,当硅整流管开路时能发出信号,在短路时能迅速解列发电机,以维护机组的安全。     

同步电机全频起动过程研究

从电机状态方程出发,提出用饱和电感及其变化率的方法处理同步电机起动时遇到的磁饱和现象,并组建了同步电机全频起动时的数学模型。对影响电机起动的几个重要因素（如线路阻抗、发电机和电动机的励磁电流、发电机的外加机械转矩,发电机的初始角,电动机的摩擦转矩和门漏转矩等）进行了详细仿真分析,并与试验结果进行了比较。     

FILTRATION CAPABILITIES OF A SPECIAL SYNCHRONOUS MACHINE

ABSTRACT

A real-time simulation model is proposed, based on one hand on the hybrid calculator principle and on the other hand on original hardware, made up of a control apparatus and DPLL, for studying the inverter-fed network operation. Moreover, we show that this simulator constitutes a powerful tool for designing the control systems. The simulator and control apparatus are based on both analog and digital components. This makes possible to change, in some limits, by varying via an interface connected to the microcomputer the values of the simulated components and also parameters relative to the PWM based control apparatus

A software written in a high level language permits, after the introduction of the different system parameters via an user- friendliness menu, the computation of the required calculations for the simulator. Hence the feasibility is established and it is shown through examples that good results can be obtained.