大型水轮发电机励磁绕组匝间短路的仿真研究
发布时间：2018-10-19 16:05
【摘要】：大型水轮发电机励磁绕组匝间短路故障影响电机的正常运行，通过多回路法计算励磁绕组匝间短路故障，得到故障前后电流的波形并分析其特征，根据定转子电流的特征，为保护方案的选择提供帮助。 本文以多回路法为基础，通过计算出的气隙磁导系数，计算出单个线圈的电感系数，依据绕组连接形式，，将单个线圈的电感系数叠加形成支路电感参数，经过支路与回路间的变换，得到回路电感参数。励磁绕组短路故障后，电感、电阻、电压矩阵的维数都增加，需要重新计算参数。着重研究了大型水轮发电机励磁绕组匝间短路故障的暂态过程，对电感矩阵中电感计算公式进行了简单的描述，同时将饱和及齿槽效应对电机的影响使用等效系数来调整。编写了比较通用的程序，对连网空载工况下的短路故障进行了仿真，谐波分析得到定子电流中接近基波频率的谐波次数幅值很大，故障特征明显。对不同匝数的励磁绕组短路故障进行了仿真，通过对比分析可以得到故障前后电流的变化趋势，结果与理论分析相符。小匝数的励磁故障对电机影响不大，但故障扩大后，将产生严重后果，针对小匝数的短路故障，找到其故障后的特征规律，为保护方案的组合提供依据和帮助。 另外简单介绍了在程序编写过程中容易出现的问题和相应的解决办法，为微分方程的初值和步长的选择提供了一些参考。
[Abstract]:The inter-turn short-circuit fault of excitation windings of large hydrogenerator affects the normal operation of the motor. The inter-turn short-circuit fault of excitation winding is calculated by multi-loop method. The waveform of current before and after the fault is obtained and its characteristics are analyzed, according to the characteristics of stator and rotor current, To assist in the selection of protection programs. Based on the multi-loop method, the inductance coefficient of a single coil is calculated by calculating the air-gap magnetic conductivity coefficient. According to the form of winding connection, the inductance coefficient of a single coil is superimposed to form a branch inductance parameter. The inductance parameters of the circuit are obtained by the transformation between the branch and the loop. The dimensions of inductance, resistance and voltage matrix are all increased after the fault of excitation winding short circuit, so the parameters need to be recalculated. The transient process of inter-turn short-circuit fault in excitation windings of large hydrogenerator is studied emphatically. The formula of inductance calculation in inductance matrix is simply described. At the same time, the effect of saturation and slot effect on motor is adjusted by equivalent coefficient. A general program is written to simulate the short-circuit fault under the no-load condition. The harmonic analysis results show that the amplitude of harmonics close to the fundamental frequency in the stator current is very large and the fault characteristics are obvious. The short circuit fault of excitation windings with different turns is simulated, and the variation trend of current before and after fault can be obtained by comparison and analysis. The results are consistent with the theoretical analysis. The excitation fault of small turns has little influence on the motor, but after the fault is expanded, it will have serious consequences. In view of the short circuit fault of small turn, the characteristic rule after the fault is found, which provides the basis and help for the combination of protection scheme. In addition, it simply introduces the problems and corresponding solutions in the process of programming, and provides some references for the selection of initial value and step size of differential equation.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM312
本文编号：2281631
[Abstract]:The inter-turn short-circuit fault of excitation windings of large hydrogenerator affects the normal operation of the motor. The inter-turn short-circuit fault of excitation winding is calculated by multi-loop method. The waveform of current before and after the fault is obtained and its characteristics are analyzed, according to the characteristics of stator and rotor current, To assist in the selection of protection programs. Based on the multi-loop method, the inductance coefficient of a single coil is calculated by calculating the air-gap magnetic conductivity coefficient. According to the form of winding connection, the inductance coefficient of a single coil is superimposed to form a branch inductance parameter. The inductance parameters of the circuit are obtained by the transformation between the branch and the loop. The dimensions of inductance, resistance and voltage matrix are all increased after the fault of excitation winding short circuit, so the parameters need to be recalculated. The transient process of inter-turn short-circuit fault in excitation windings of large hydrogenerator is studied emphatically. The formula of inductance calculation in inductance matrix is simply described. At the same time, the effect of saturation and slot effect on motor is adjusted by equivalent coefficient. A general program is written to simulate the short-circuit fault under the no-load condition. The harmonic analysis results show that the amplitude of harmonics close to the fundamental frequency in the stator current is very large and the fault characteristics are obvious. The short circuit fault of excitation windings with different turns is simulated, and the variation trend of current before and after fault can be obtained by comparison and analysis. The results are consistent with the theoretical analysis. The excitation fault of small turns has little influence on the motor, but after the fault is expanded, it will have serious consequences. In view of the short circuit fault of small turn, the characteristic rule after the fault is found, which provides the basis and help for the combination of protection scheme. In addition, it simply introduces the problems and corresponding solutions in the process of programming, and provides some references for the selection of initial value and step size of differential equation.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM312
【引证文献】
相关硕士学位论文 前1条
1 李梦乔;水轮发电机定子叠绕组内部故障的暂态分析[D];哈尔滨理工大学;2015年
本文编号：2281631
本文链接：https://www.wllwen.com/kejilunwen/shuiwenshuili/2281631.html
