MONITORING DEVICE FOR MONITORING AN ELECTRICAL ENERGY SOURCE WITH RESPECT TO THE SOURCE VOLTAGE THEREOF AND THE INSULATION RESISTANCES THEREOF, HIGH-VOLTAGE SYSTEM, AND METHOD FOR OPERATING THE MONITORING DEVICE

摘要

The invention relates to a monitoring device (21) for monitoring an electrical energy source (12). The monitoring device (21) has a measurement circuit (26, 27) for each pole (13, 14) of the energy source (12), each measurement circuit being designed to connect the pole (13, 14) to a reference potential (KL31) by means of a voltage divider (29, 30). An evaluation apparatus (32) is designed to capture a voltage value (Um1, Um2) at each voltage divider (29, 30) and to determine a source voltage indication (22) with respect to a source voltage (Ubat) of the energy source (12) on the basis of the captured voltage values (Um1, Um2). According to the invention, the total electrical resistance (Rg+, Rg-) of at least one of the measurement circuits (26, 27) depends on a switching state of an associated switching element (38), and the evaluation apparatus (32) is designed to set at least two different switching constellations (S1, S2, S3) of the measurement circuits (29, 30) by switching the switching element (38) in question and to determine, altogether, resistance indications (23) with respect to insulation resistances (Riso+, Riso-) of the energy source (12) on the basis of the voltage values (Um1, Um2) captured when the switching constellations (S1, S2, S3) were set.