Power distribution feeders carry a high neutral current than expected due to the increased integration of low carbon technologies. The number of small photovoltaic units and electric vehicle chargers in the system has increased. These unpredictable, nonlinear, single‐phase sources and loads are difficult to balance among phases. The nonlinear power electronic devices produce harmonics. Phase unbalance and harmonics cause high neutral current, resulting in more neutral to earth voltage (NEV) and neutral heating. Neutral line grounding is critical in earth fault protection. In this article, a new neutral line grounding practice is proposed that can improve power quality in three phase four wire distribution systems, without installing any additional equipment. The presence of neutral current and mutual coupling between the lines is utilized to reduce voltage regulation, unbalance, and harmonics. The earth fault current and NEV is also reduced, but with a slight increase in line loss. The method is verified by an analysis conducted in the IEEE low voltage test feeder, using OpenDSS, a distribution system simulation tool developed by EPRI.

中文翻译：

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利用配电系统中性电流改善电能质量

由于低碳技术的日益集成，配电馈线的中性线电流比预期的高。系统中小型光伏组件和电动汽车充电器的数量已经增加。这些不可预测的非线性单相电源和负载很难在各相之间进行平衡。非线性电力电子设备会产生谐波。相位不平衡和谐波会导致高中性线电流，从而导致更多中性线对地电压（NEV）和中性线发热。中性线接地对于接地故障保护至关重要。在本文中，提出了一种新的中性线接地做法，可以在不安装任何其他设备的情况下改善三相四线配电系统的电能质量。利用零线电流和线路之间的相互耦合来减少电压调节，不平衡和谐波。接地故障电流和NEV也降低了，但线损耗略有增加。该方法通过使用EDS开发的配电系统仿真工具OpenDSS在IEEE低压测试馈线中进行的分析得到验证。