基于STM32故障电弧检测装置的设计

A Design of Arc Fault Detecting Device Based on STM32

摘要:

对负载电流信号的检测是判断低压配电线路中是否发生电弧故障的有效方法之一。用ADC模块对负载电流信号进行采样，将发生电弧故障时的电流波形与正常工作时的电流波形相比较，检测是否有电弧故障发生。比较的电流波形特征量主要有过零点后的上升率、电流正半周期采样时间宽度和正半周期采样幅值，将这三个特征量作为电弧故障识别算法的判断条件，检测电弧故障。为了在硬件上验证该时域检测算法的可行性和有效性，将电弧故障检测算法移植到STM32平台，设计出了一台基于STM32的故障电弧检测装置样机。该样机可以实现电流信号采集、过零点检测、数据处理以及串联电弧故障检测识别。在以日光灯、开关电源和吸尘器为屏蔽负载的实验结果表明，该装置可以检测出串联电弧故障，且可靠性高，不会在没有产生故障电弧的情况下产生误判。

Abstract:

Current signal inspection is an effective method to determine whether fault arcs occur in a low-voltage distribution line. Current signals are sampled by an ADC converter. Using current signals as the characteristic, differences between the rising rates, sampling times and magnitudes of two current waveforms are used as the judging conditions of fault arcs. To verify the feasibility and effectiveness of the arc fault detection algorithm in time domain by hardware, the algorithm was implemented on an STM32 platform, and a prototype of a fault arc detection device was designed. The prototype acquires current signals, performs zero-crossing detection, and achieves series arc fault recognition. In the experiment which uses fluorescent lamps, switch power supplies and vacuum cleaners as shielding loads, the device can detect series fault arcs and perform high-reliability, with avoidance of misjudgments when no arc occurs.