On the Design of an Islanding, Neutral Loss and Meter Tampering Detection Kit for Low Voltage Electrical Installations

This paper proposes a kit for the detection of unintentional islanding, neutral conductor loss and meter tampering (i.e., electricity or power theft) events, applicable to low voltage electrical installations, in the prospect of mass penetration of distributed generation and energy storage units in buildings. A simple, compact and flexible technical solution is studied, by utilizing a low-power H-bridge inverter and a current transformer, along with voltage and current sensing. Moreover, the kit is compatible with TN/TT distribution networks, it is self-powered, whereas it features advanced IoT communication capabilities (by the aid of the ESP32 microcontroller), facilitating its connectivity with various smart home devices. The detection is based on the injection of a zero-sequence voltage harmonic component, in series with the electrical grid voltage and the measurement of the corresponding harmonic current. The theoretical analysis of the detection kit is presented; its functionality and effectiveness are validated through MATLAB/Simulink simulations. Finally, the design process of a hardware prototype is presented and discussed, whereas indicative experimental results highlight its functionality and good performance.