继电保护抗TA暂态饱和改进Prony算法

Improved Prony algorithm against transient CT saturation for relay protection

针对TA暂态饱和引起的保护不正确动作,基于Prony算法原理,提出一种抗TA暂态饱和的改进算法。该方法给定50 Hz工频量对应特征根,利用奇异值分解(SVD)降阶,选择最接近最优采样率的频率进行采样,以在短数据窗条件下,提高计算结果准确性并减少计算量。TA暂态饱和试验数据及实际故障录波数据计算结果证明在短数据窗内,改进Prony算法仅利用TA二次电流的非饱和段数据,就可快速提取故障电流有效信息;通过仿真算例验证了改进Prony算法能在发生转换性故障情况下,保证继电保护正确动作。

The transient CT（Current Transformer） saturation may cause the malfunction of relay protection, for which an improved Prony algorithm is proposed. In order to improve the calculation accuracy and decrease the calculation load in short data window,it sets the eigenvalues corresponding to 50 Hz,adopts SVD（Singular Value Decomposition） to reduce the order and acquires data with the sampling frequency nearest to the optimal one. Data of transient CT saturation experiments and calculative results based on actual fault recording data demonstrate that,the useful information of faulty currents can be quickly extracted out by the proposed algorithm only based on the unsaturated section of CT secondary current in short data window. Results of case simulation also show that,the proposed algorithm guarantees the proper operation of relay protection during fault transfer.