基于时频域参数分析的直流电弧故障检测装置

DC Arc Fault Detection Device Based on Time-Frequency Domain Parametric Analysis

针对现有的直流电弧故障检测方法容易受到环境影响,无法实现精准检测,且算法结构复杂,难以部署于实际应用,基于短时傅里叶变换设计一种直流电弧故障检测算法。通过分析电弧电流信号在频域上的幅值变化趋势,将频谱划分为不同的阶段,计算不同阶段频率积分的比值,根据大量实验结果得到判定的阈值从而实现电弧故障检测。最后,选择合适的单片机实现检测算法并进行测试,验证所提算法的有效性。结果表明,所提算法不仅能在多种类型负载并联的情况下及时检测出电弧故障,检测的准确率可达94.4%,而且在面对正常状态电流时的误判率为0,证明其具有较好的稳健性。

However,the existing DC arc fault detection methods are easy to be affected by the environment,which can not achieve accurate detection,and the core algorithm is complex,difficult to deploy in practical applications.To solve these problems,a DC arc fault detection algorithm based on short-time Fourier transform is designed.By analyzing the amplitude variation trend of arc current signal in frequency domain,the spectrum is divided into different stages,the ratio of different stages is calculated,and the threshold value is obtained according to a large number of experimental results to realize arc fault detection.Finally,a suitable single chip microcomputer is selected to implement the detection algorithm and tested to verify the effectiveness of the proposed algorithm.The results show that the algorithm is not only able to detect arcing faults in a timely manner with multiple types of loads connected in parallel,the accuracy of detection can reach 94.4%.In addition,the algorithm has a misjudgment rate of 0 in the face of normal state currents,which indicates that it has good robustness.