| 摘要 |
The invention relates to an insulation monitoring device (IMD) in a non-grounded electrical DC grid (DC-IT System), particularly an electrical photovoltaic system (PV). Said device has a power supply unit (B), which is supplied with electrical energy from the electrical DC grid (DC-IT System). According to the invention a rechargeable energy store (CIMD) is present, in particular a capacitor with a charging diode (D) connected upstream. This is supplied with electrical energy (UIMD) via the electrical DC grid and supplies the power supply unit (B) in the event of a temporary failure of the electrical DC grid, so that continued operation of the insulation monitoring device (IMD) is possible until the non-grounded electrical DC grid is re-established. Advantageously, for continued operation of the insulation monitoring in the event of failure of the electrical DC grid the power supply unit (B) provides a preferably pulsed measurement voltage (UP), which is used in order to feed electrical energy into the electrical DC grid (DC-IT) via a coupling circuit (AS). |
