基于线圈电流的牵引变电站直流断路器状态监测与诊断研究

直流断路器在系统设备入网或者退网时起到开关转换的控制作用，是电力系统的关键设备之一。研究牵引变电站直流断路器的合分闸线圈电流与直流断路器状态的联系，实现对直流断路器的状态诊断。首先利用霍尔电流传感器采集分合闸线圈电流波形，然后分析了直流断路器分合闸过程线圈电流的变化机理并确定以电流拐点的时间(t1/t2)和电流值(i1/i2)作为诊断的特征值，接着对采集的电流波形进行15kHz低通滤波去噪后采用电流包络法提取分合闸线圈电流信号中特征值，最后随机划分80%样本为训练样本，20%为测试样本，通过SVM支持向量机对模拟的7种不同状态进行诊断。诊断结果表明，通过分析分合闸线圈电流的特征值能够实现牵引变电站直流断路器的状态监测与诊断。

Research on Condition Monitoring and Diagnosis of DC Circuit Breaker Based on Coil Current

DC circuit breaker is one of the most important switch devices in power system, Which plays the role of switching control when the system devices enter or exits the system. The connection between the closing/opening coil current and the state of the DC breaker are studied, to diagnosis the DC breaker status. Firstly, the current waveform of the opening and closing coil is collected by the Hall current sensor. Then, analysis the coil current in the DC circuit breaker opening/closing process is analyzed and the time (t1/t2) with current value (i1/i2) of the coil current inflection point are determined as the characteristic values of the diagnosis. and then, the collected current waveform is denoised by low-pass filtering with a cutoff frequency of 15 kHz that is extracted by the method of current envelope. Finally, 80% of the samples were randomly divided into training samples and 20% were test samples. Seven different states of the simulation were diagnosed by SVM. The diagnosis results show that the analysis method based on the current of the coil current can realize the condition monitoring and diagnosis of the dc circuit breaker in traction substation.