Abstract A number of changes in the power system have increased the risk for more serious resonances in the harmonic frequency range. The changes also result in an increased uncertainty with regard to the frequency and damping of those resonances. Uncertainties could be related to variations with time, uncertain future developments in the grid, and the modelling of individual components. This article investigates uncertainties affecting resonant overvoltages caused by transformer energization. Several study cases investigating the impact of different uncertainties on resonances and resonant overvoltages, performed in PSCAD, are presented. The results show that some uncertainties may have a significant impact on the resulting impedance characteristics and on the resulting overvoltage levels.

中文翻译：

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不确定性对变压器通电后谐振过电压的影响

摘要 电力系统的许多变化增加了谐波频率范围内更严重谐振的风险。这些变化还导致关于这些共振的频率和阻尼的不确定性增加。不确定性可能与时间变化、电网中不确定的未来发展以及单个组件的建模有关。本文研究了影响变压器通电引起的谐振过电压的不确定性。介绍了在 PSCAD 中执行的几个研究不同不确定性对谐振和谐振过电压影响的研究案例。结果表明，一些不确定性可能对产生的阻抗特性和产生的过电压水平产生重大影响。