中文摘要：

含有特殊负荷的大型厂矿局部电网振荡问题时有发生。针对某钢铁企业存在的实际振荡问题,初步分析事故原因,并仿真分析冲击负荷相关因素及企业内部发电机组励磁方式对该电网振荡的影响。结果表明,特殊负荷的位置、冲击幅度及企业内部发电机组励磁方式对局部电网振荡的影响较显著。负荷冲击幅度越大,越易引发振荡;冲击负荷与发电机组电气距离越近,越易引发振荡;发电机组选用恒功率因数励磁方式时,容易引发振荡。仿真结果验证了理论分析结论。根据仿真分析结果,建议厂矿企业局部电网内部发电机组选用恒电压励磁方式;加强局部电网与大电网的电气联系;同时合理布局企业内部的冲击负荷。

英文摘要：

The local oscillation occurs occasionally in the electric network of large-sized mine. This paper focuses on the oscillation problem in a steel enterprise with a mass of special loads. The possible reasons of the local oscillation is analyzed firstly, and then the simulation considering the mentioned reasons including the impact characters of special load, the excitation mode of local generators, etc. are implemented. It is manifested that the changes of impact load, the location of impact load and the excitation mode of a local generator may significantly affect the oscillation in the small grid. Moreover,the larger the change of impact load is, the larger possibility of the oscillation will be, and the closer the distance between the impact load and generators is, the more significant the oscillation will be. If the exciter of local generator is operated in the constant power factor mode, the generator tends to oscillate more easily than in other modes. The simulation results suggest that the constant voltage mode is a good choice for the exciting regulator, connecting the local grid to the outer power grid improves its reliability, and the impact loads should be reasonably distributed.