Leakage current based remote monitoring device and method for disconnector devices

An electrical connection status monitoring system comprising an electrical connection status determining unit and a leakage current measuring device,

• a leakage current measuring device comprising a leakage current sensor for measuring a leakage current IL flowing along a grounding path, the leakage current IL being indicative of the electrical connection status of a disconnector device, the electrical connection status being one of an activated and an inactivated status of the disconnector device,
• an electrical connection status determining unit configured to be connected to the leakage current measuring device, the electrical connection status determining unit comprising:
• an input section configured to receive, from the leakage current measuring device, leakage current data indicative of the leakage current IL,
• a determining section, the determining section being configured to determine, from the leakage current data, the electrical connection status of the disconnector device, and
• an energy supply comprising at least one of a battery and an energy harvesting system having a circuit arrangement for harvesting energy from the leakage current flowing along the grounding path,
• wherein the electrical connection status determining unit is connected to the leakage current measuring device for receiving the leakage current data from the leakage current measuring device.

A method for monitoring an electrical connection status of a disconnector device of a grid protection system protecting a power distribution or transmission grid from damage in case of a power surge,

• the grid protection system including the disconnector device and a surge arrester connected in series along a grounding path, the grounding path connecting a phase of a power distribution or transmission grid through the surge arrester and the disconnector device to ground,
• the disconnector device being configured for being activated in case of an overload condition, thereby disconnecting the surge arrester,
• the method comprising:
• measuring, by a leakage current sensor, a leakage current IL flowing along the grounding path;
• and
• determining, by a determining section based on the measured leakage current IL, an electrical connection status of the disconnector device, the electrical connection status being one of an activated and an inactivated status of the disconnector device.