固相气流切除雷击短路故障下电力系统暂态稳定性分析

Transient Stability Analysis of Power System Under Lightning Short Circuit Fault Removed With Solid-Phase Airflow

随着我国电力负荷的不断增加,各种新能源、新技术的不断投运,电力系统的稳定性问题也愈发的复杂。系统在受到大扰动后,断路器难以在极限切除时间和极限切除角内切除故障。雷击引起短路故障是系统发生大扰动的原因之一,然而当线路安装固相气流灭弧防雷设备之后,可通过快速灭弧方式切断短路故障。为分析固相气流灭弧防雷间隙切除雷击短路故障对电力系统暂态稳定性的影响,利用固相气流灭弧防雷间隙改进后的Mayer电弧模型作为短路点的等效接地电阻,将该模型与传统发电机转子状态方程结合,求解了两者耦合后的微分方程,并详细介绍了该方程基于改进欧拉法在MATLAB仿真环境中的程序设计,求解出功角与相对角速度的摇摆曲线,并与传统的断路器切除方式对比,得出固相气流灭弧防雷间隙切除雷击短路故障可大幅度提高了电力系统暂态稳定性。

With continuous increase of electric power load in China,various new energy sources and new technologies have been continuously put into operation,and stability ot electric power systems becomes increasingly complicated. When the system is subjected to large disturbances,it is difficult for circuit breaker to remove the fault within limit removal time and limit removal angle.The short circuit caused by lightning stroke is a cause of large disturbance in the system. However,if solid-phase airflow arc-extinguishing lightning protection gap(SPAF-AELPG)is used,the short-circuit fault can be cut off rapidly.The main purpose of this paper is to analyze impact of lightning and short circuit faults on transient stability of the power system with SPAF-AELPG.The improved Mayer arc model takes SPAF-AELPG as the equivalent grounding resistance at short-circuit point,and combines traditional generator rotor state equations to solve coupled differential equations,and a program is designed based on the improved Euler method in MATLAB to solve the power angle and relative angular velocity.The rocking curve is compared with the result obtained with traditional method.It is concluded that SPAF-AELPG can greatly improve transient stability of power system.