Detection of broken neutral conductor in LV networks to ensure customer safety

The increased electrification is intensifying the stress on the existing Low Voltage (LV) network. This shortens the lifespan of network components and increases the likelihood of faults arising in LV cables, threatening the stability of the system. A damaged neutral can pose a significant risk to network operation. In this scenario, phase unbalance can lead to abnormal voltages, which may damage household appliances. In certain earthing systems, such as TN-C or TN-C-S, where the connection to earth is done by a combined Protective Earth and Neutral (PEN) conductor, the customer can lose their connection to ground, and exposed metallic parts may become live. For example, a broken neutral fault can liven the metal body parts of an Electric Vehicle (EV), posing extreme risk to EV users. This safety hazard led us to develop a new LV Broken Neutral detection algorithm, which identifies, in real-time, the signature of these events. The method has been tested at PNDC (University of Strathclyde, Scotland), for different earthing systems (TT, TN-S and TN-C-S), load configurations and fault locations. This paper presents the promising results of the experiments carried out at PNDC and a performance assessment of the LV Broken Neutral detection method developed by Eneida.