基于励磁与调速控制的单机无穷大系统场-路-网时步有限元建模

Modeling of Field-Circuit-Network Coupled Time-Stepping Finite Element for One Machine Infinite Bus System Based on Excitation and Speed Control

为了能更准确地分析在整个电力系统受到干扰或出现故障时发电机与电网相互影响的动态问题,建立含有励磁调节系统和转速控制系统的场-路-网耦合时步有限元模型。该模型不但考虑了发电机磁场饱和、畸变以及趋肤效应等非线性因素对电机的影响,同时还考虑了转速的动态变化以及变压器和输电系统参数的影响,并给出了励磁调节系统和转速控制系统的实现方法。为验证模型的正确性,以一台1 407 MV·A汽轮发电机为例,采用该模型对发电机额定并网运行情况下,变压器二次侧(高压侧)A相断路器突然断开这一非全相暂态过程进行了仿真,并与传统的Park方程计算结果进行对比分析,验证了建立的场-路-网耦合时步有限元模型的正确性。

In order to accurately analysis the dynamic problem of the interaction between the generator and power network under the condition of the disturbance and the faults in the whole system,a field-circuit-network coupled time-stepping finite element model containing excitation system and speed control system was presented. Not only the nonlinear feature,including the magnetic saturation,distortion of electromagnetic field and eddy current were considered,but also the dynamic change of speed and parameters of transformer and power transmission system were considered. The implement measures of excitation system and speed control system were given. To verify the model,Take a 1 407 MVA turbo-generator as an example,the transient process of the open phase fault was simulated. This transient process was simulated when the generator is running under rated operating condition which connects with power network,and the A phase breaker of transformer secondary side（ high voltage side） was suddenly turned off. Compared with the result of traditional Park equation,the fieldcircuit-network coupled time-stepping finite element model is verified.