A Safety Case for the Use of Bipolar +-60V DC for Microgrids - Raw Arcing Data

The data herein forms part of the work, 'A Safety Case for the Use of Bipolar ±60V DC for Microgrids'. The application of entirely DC systems for PV microgrids are gaining proliferation as they do not require inefficient conversion between AC & DC. However, the application of DC for power distribution increases the likelihood of series arcs. In the case of AC distribution, series arcs are generally extinguished as the voltage crosses 0V. As this does not occur with DC distribution, series arcs tend to sustain resulting in heating, damage and potentially fires.In order to test an arc detection and extinguishing algorithm, a laboratory experiment was set up to simulate a break in the intended path of current of a 120V DC circuit. Whilst current is flowing in the circuit, an opening can be created in the conducting path using a pair of brass electrodes, drawn apart in a controlled and repeatable manner by means of a precision stepper motor. The electrodes are mounted in a frame to allow separation in one axis. One electrode is held in place while the other is mounted on a stepper motor shaft. The voltage across the arc gap is recorded using an oscilloscope and two voltage probes in differential arrangement.An arc is formed in the gap upon initial separation. The opening of the gap represents a longitudinal break in the conductive path of a DC microgrid feeder. The stepper motor driver is controlled by a microcontroller, programmed to govern the velocity and final separation distance of the electrodes. A series arc is then established in the opening between the electrodes. This experimental set up for arc testing, commonly referred to as the ‘pull apart’ method conforms with the standard UL1699B for testing arc fault detectors in PV systems.The file name represents the separation in mm and the speed of separation (FS - Full speed, HS - Half speed), however the exact speed of separation was not recorded. Column A represents time (s). The values of columns B & C represent the voltages measured on the two channels (A & B) of an oscilloscope. The data is also presented in pico-scope data file format.For further information and results analysis please refer to 'A Safety Case for the Use of Bipolar ±60V DC for Microgrids' available through IEEE Access.

本数据集属于研究成果《面向微电网的双极性±60V直流系统应用安全论证》（A Safety Case for the Use of Bipolar ±60V DC for Microgrids）的一部分。光伏微电网全直流系统的应用正日益推广，因其无需在交流与直流之间进行低效的电能转换环节。然而，直流配电场景下串联电弧发生的概率会有所提升。在交流配电场景中，串联电弧通常会在电压过零点时自行熄灭；但直流配电不存在电压过零点的特性，会导致串联电弧持续燃烧，进而引发发热、设备损坏乃至火灾风险。为验证电弧检测与熄弧算法的性能，本研究搭建了实验室实验平台，用于模拟120V直流电路的预设电流通路断裂场景。当电路处于通电状态时，通过精密步进电机以可控且可重复的方式拉开一对黄铜电极，即可在导电通路中制造断路。电极安装于单轴可分离的支架结构中：其中一枚电极固定不动，另一枚安装在步进电机的转轴上。采用差分配置的两支电压探头配合示波器，采集并记录电弧间隙两端的电压数据。电极初始分离时，间隙中即刻形成电弧；该间隙的断路场景对应直流微电网馈线导电通路的纵向断裂。步进电机驱动器由微控制器控制，通过预设程序调控电极的分离速度与最终间距，由此在电极间隙间形成串联电弧。这套电弧测试实验装置通常被称为“拉开法”，符合光伏系统电弧故障探测器测试的UL1699B标准。文件名包含电极分离间距（单位：毫米）与分离速度信息（FS代表全速，HS代表半速），但未记录实际的分离速度数值。数据列A代表时间（单位：秒），数据列B与C的数值分别为示波器A、B通道采集到的电压数据。本数据集同时以PicoScope数据文件格式存储。如需获取更多研究信息与结果分析，请参阅发表于IEEE Access的《面向微电网的双极性±60V直流系统应用安全论证》。