有载调压变压器对电力系统电压稳定的影响分析

为研究含有载调压变压器电力系统的电压稳定问题,文章基于分岔理论分析了含有载调压变压器单机无穷大系统负荷变化对电压稳定的影响,讨论了有载调压变压器在维持系统电压稳定中的作用及其调压策略中闭锁、延时以及等值电抗对系统电压稳定的影响。结果表明:在系统接近电压崩溃极限时,闭锁有载调压变压器分接头能使负荷节点电压维持在较低水平,有助于避免系统电压崩溃;较短的延时虽不能避免电压崩溃的发生,但有效延缓了电压崩溃的发生速度;较小的等值电抗会使系统电压受到较为明显的干扰。

Analysis for the Effect of On-Load Tap Changeron the Power System Voltage Stability

In order to research the voltage stability of power system including OLTC, this paper, which is based on the bifurcation theory, analyses the influence of load on voltage stability in single machine infinite bus power system including OLTC. Then, the function of OLTC in sustaining the system voltage stability and the influence of locking and delay in the regulating strategy and the equivalent reactance on system voltage stability are discussed.The results show that: when the system is close to the limit of voltage collapse, locking the tap of OLTC can sustain the voltage of load node at a relatively low level, which is conductive to avoid the system voltage collapse. And a short delay is effective in delaying the speed of voltage collapse. A smaller equivalent reactance will lead to a more obvious interferenceSreceived byStheSsystem voltage.