短路故障下单机无穷大系统的暂态稳定仿真分析

Transient Stability Simulation Analysis of a Single-machine Infinite System Under Short-circuit Fault

电力系统暂态稳定性是评估电力系统安全稳定运行的重要指标。短路故障是电力系统暂态稳定分析中最常见的大干扰信号,因此着重分析短路故障情况下电力系统暂态稳定变化特性。当系统发生短路故障时,根据发电机转速变化曲线可判断系统暂态稳定性。通过改进欧拉法对发电机转子运动方程进行数值求解,获得发电机转速的数学计算模型。采用单机无穷大系统模拟实际电力系统,建立短路故障下暂态仿真模型,从切除故障时间和调节发电机励磁系统两个方面分析电力系统暂态稳定性,结果发现通过快速切除故障和调节励磁放大系数均可保障系统的稳定性。研究成果可为电力系统稳定性的分析和控制提供有力的支持。

Transient stability is an important indicator for assessing safe and stable operation of the power system.Short-circuit faults are the most common major disturbance signals in power system transient stability analysis.This paper focuses on characteristics of transient stability changes in power systems under short-circuit fault conditions.When a short-circuit fault occurs,transient stability of the system can be judged based on the change curve of the generator's rotational speed.In this paper,by using an improved Euler method,the equation of generator rotor motion is numerically solved and a mathematical calculation model for the generator's speed is obtained.The actual power system is simulated using a single-machine infinite system,and a transient simulation model under short-circuit faults is established.The transient stability of power system is analyzed from the two aspects of fault cutting time and excitation system adjustment.It is found that the stability of the system can be ensured by quickly cutting off the fault and adjusting the excitation amplification coefficient.The research results can provide strong support for analysis and control of power system stability.