交流传动系统网侧电流信号异常实时诊断与容错控制

Real-time Diagnosis and Fault-tolerant Control of Grid-side Current Signal Anomaly in AC Traction System

目前,交流传动机车在现场运用中经常出现因网侧电流信号异常而误报牵引系统网侧接地故障的现象,其会致使机车执行保护动作甚至导致机破。为解决此问题,文章提出一种基于多工况非线性模型的网侧电流信号异常实时诊断方法。首先,其基于系统机理和工程设计经验,提取与网侧电流强相关的变量,建立网侧电流的多工况非线性估计模型;其次,基于牵引传动系统两个互为冗余的网侧电流信号并结合网侧电流估计值,设计残差及检测统计量,并结合CUSUM算法实现针对两路网侧电流信号异常的有效故障检测与决策;最后,根据故障决策结果采用不同的容错控制策略,保证系统正常的控制与保护功能。现场数据测试结果表明,该算法在异常发生0.3 s后,实现了网侧异常的及时检测与精准定位,规避了现场因网侧信号异常导致的故障影响。

In order to solve the problem of locomotive failure caused by the fault of grid-side grounding due to misinformation of grid-side current signal in the application of AC locomotive,a real-time diagnosis method for grid-side current signal anomalies based on multi-operating condition nonlinear model is proposed in this paper.Firstly,based on the system mechanism and engineering design experience,the variables strongly related to grid-side current are extracted,and a multi-operating condition nonlinear estimation model of grid-side current is established.Secondly,based on the two redundant grid-side current signals of the traction drive system and the estimated value of the grid-side current,residual and detection statistics were designed,and the effective fault detection and decision-making of the two grid-side current signal anomalies are achieved by combining the CUSUM algorithm.Finally,different fault-tolerant control strategies are adopted according to the fault decision-making results to ensure the normal control and protection functions of the system.Field data tests show that the proposed diagnostic method achieves timely detection and precise positioning of grid-side anomalies 0.3 s after the occurrence of anomalies,avoiding the impact of on-site faults caused by grid-side signal anomalies.