Electric-Leakage Detection System based on Non-contact Electric-field Sensor for Remote Street Fixture Monitoring

We propose an electric-leakage detection system for remote monitoring of street fixtures, such as streetlights. The electric-leakage phenomena caused by the aging of underground power lines can be hazardous. Since various street fixtures are installed at a wide variety of locations, there is a need for a detection system that is easy to install and applicable to multiple fixtures. The proposed system consists of a non-contact electric-field sensor and method of calculating the electric-leakage voltage. The sensor measures the degree of the object voltage without any Ohmic contact by measuring the electric-field strength radiated from the fixture, making the sensor easy to install. However, even fixtures in the same hazardous will radiate different electric-fields since their structures differ. The finite element method simulation is conducted to determine the conversion factor related to the structure of a fixture. A streetlight, which is particularly prone to leakage, was modeled as a cylindrical metal pole, then the conversion factor was calculated with respect to the radius and height of the sensor. From a pseudo-electric-leakage detection experiment using prototypes of the sensor, a linear response of 93% accuracy was obtained for an applied voltage of 0-10 V.