发电机外部故障切除后励磁调节器动态特性仿真研究

摘要

励磁调节器改善了发电机的调压特性,但对其引入电流测量值后的分析存在不足.为了研究电流测量值对励磁调节器调整特性的影响,分别建立了发电机单机运行和并网运行两种仿真模型,得到了两种运行状态下励磁调节器的调整特性,并利用戴维南等效电路对励磁调节器中的电流进行分析.仿真分析结果表明,励磁调节器在发电机单机运行和并网运行故障切除后的调整特性不同,且引入的电流测量值是由发电机电势与系统电势矢量差振荡产生,是呈低频振荡特性的交流电流;仿真进一步表明,加装自动励磁调节器后会在一定程度上加剧发电机与系统间的低频振荡.%Excitation regulator plays a positive role in improving the voltage adjustment characteristics of the gen-erator;however, the analysis after the introduction of current measurement is not enough.To study the influence of cur-rent measurement value on the excitation regulator's adjustment characteristics, two simulation models were established under the generator's unit operation and grid-connected operation conditions, respectively, and the corresponding ad-justment characteristics were obtained. Thevenin's equivalent circuit was used to analyze the current in the excitation regulator. Simulation results showed that the adjustment characteristics of the excitation regulator were different under the generator's unit operation condition and grid-connected operation condition(after the fault removal); the introduc-tion of current measurement value was induced by the vector difference between the generator potential and the system potential, and it was an alternating current with low-frequency oscillation characteristics.Simulations further showed that the addition of an excitation regulator would exacerbate the low-frequency oscillations between the generator and the sys-tem to a certain extent.