兼顾源网安全的大规模电力外送基地多机失步保护动作策略

Multi-generator out-of-step protection strategy for large-scale power transmission base

在大规模电力外送基地中常规能源与新能源打捆外送的趋势日趋明显。针对系统发生多机失步时,发电机安全与电网完整性对发电机失步保护要求的矛盾性,提出一种兼顾源网安全的大规模电力外送基地多机失步保护动作策略,切除最小机组保全系统稳定。立足于大规模电力外送基地多机失步的原因分析,基于等面积定则,提出多机失步下系统稳定控制策略。并从理论上分析和计算了在线路故障与负荷突变时系统稳定最优切机数,提高了系统的稳定性。最后,基于多机组并联外送系统的仿真模型验证了所提出的最小切机策略,通过功角曲线变化说明了该策略的有效性。

The trend of bundling regular and new energy has become apparent increasingly in large-scale power transmission base.There is a contradiction between the safety of generator and integrity of grid for multi-generator out-of-step protection.Therefore,multi-generator out-of-step protection action strategy is proposed for large-scale power transmission base considering the safety of both source and grid,maintaining system stability by removing the optimal unit in this paper.By analyzing the causes of multi-generator out-of-step in a large-scale power transmission base,this paper proposes a system stability control strategy under multi-generator out-of-step based on equal area criterion.The optimal cuts number of the system when line faults and loads change suddenly is analyzed and calculated theoretically,improving the stability of the system.Finally,simulation model based on delivery system of multi-unit in parallel verify the minimum cuts strategy proposed in this paper.The effectiveness of the strategy is illustrated by the change of the power angle curve.