基于简化模型的变压器励磁涌流计算方法

Calculation Method of Transformer Inrush Current Based on Simplified Model

提出一种基于简化模型的变压器励磁涌流及电压计算方法。将变压器励磁电路的电流-磁通特性由非线性模型简化为线性模型,基于线性模型进行公式推导,得到励磁涌流及电压计算公式,并进行验证试验。试验结果表明,利用简化计算公式得到的励磁涌流和电压与瞬时分析法相比误差不超过0.012%。本文方法能够有效防止励磁涌流误动,提高电网系统的继电保护水平。

This study proposed a simple calculation method for transformer excitation inrush current and voltage.This method first simplifies the current magnetic flux characteristics of the transformer excitation circuit from a nonlinear model to a linear model,and then deduces the analytical formula based on the linear model,the calculation formulas for excitation inrush current and voltage are obtained.The experimental results show that the error in the magnitude and voltage of the excitation inrush current obtained by using the simplified calculation formula does not exceed 0.012%compared with the instantaneous analysis method.This method can effectively prevent the maloperation and improve the relay protection level of the power grid system.