基于双频有源调控的大型机组定子接地故障电弧抑制及自适应保护

随着“碳达峰、碳中和”目标部署的实施,在新型电力系统中,因大型旋转电机需要担负更重要的功率调控和稳定支撑作用而对其提出了更高的安全平稳运行要求。对于最易发生的定子接地故障,如何有效抑制机组电弧损伤和避免刚性切机冲击显得尤为重要。首先提出基于双频有源调控的大型机组定子接地故障消弧和限流方法,可实现瞬时性故障治愈、永久性故障安全限流,保障定子铁心安全。其次提出与有源消弧协同的接地故障自适应保护方法,可实现柔性平稳切机控制,提高机组和电网的安全性。最后通过仿真和动模试验验证了所提方法的有效性,其消弧和限流效果优于现有无源消弧方法。

Dual-frequency active regulation-based arc suppression and adaptive protection for a stator ground fault in large generators

With the implementation of a "carbon peak and carbon neutral" strategy, in new power systems, since the large rotating generators need to shoulder the responsibility of necessary power regulation and stable power support, their safe and stable operation is important. For the most prone stator ground faults, it is important to restrain the arc damage and avoid the impact of rigidly cutting the generators. In this paper, a method of ground fault arc suppression and fault current limiting is proposed based on dual-frequency active regulation for large generators. This can cure the transient faults, and limit the fault current to ensure the stator iron core safety for permanent faults. An adaptive ground fault protection method cooperating with active arc suppression is proposed, and this can realize flexible generator tripping control, and improve the safety of the generator and the power grid. The effectiveness of the proposed method is verified by simulation and dynamic test. Its arc suppression and fault current limiting effects are better than the existing passive arc suppression methods.