与长线相联的发电机自励磁仿真与实验

Simulation of self -excitation of generators connected to long transmission lines

为了解决青海省长距离输电线路对地电容造成的末端小水电自励磁问题 ,利用 PSCAD/EMTDC软件进行了仿真 ,并进行了三机对无穷大系统的动模实验 ,两者结果基本一致。对仿真和动模实验中的各种现象进行了解释 ,总结出一些关于自励磁现象发生条件和表象形式的一般规律 ;并提出了破坏谐振参数、改善励磁、调整运行方式、改变变压器分接头等抑制自励磁的解决措施 ,是对原有自励磁理论的仿真与实验补充。

The significant capacitance effects of long transmission lines may cause self excitation in small generators connected to the main electric grid by such long lines in less populated areas such as western China. Numerical simulations of the Qinghai provincial grid using PSCAD/EMTDC code agreed with experimental results of a three -machines analogous system. The various phenomena were analyzed to understand the principle for self -excitation waveforms. And some measures, such as destroying the parameters of the resonance, improving the excitation system, alternation of the adapters of sub -transformers, and so on, were recommended to restraint the self -excitation waveforms via simulations and experiments.