Electrical system and method for diagnosing functionality of power relays in electrical system

An electrical system and a method for diagnosing the functionality of power relays in the electrical system are disclosed. The invention relates to an electrical system that comprises at least one high-voltage battery pack, at least one intermediate circuit capacitor and at least two power relays, wherein one power relay is arranged between a positive connection end of the high-voltage battery pack and the intermediate circuit capacitor, while the other power relay is arranged between a negative connection end of the high-voltage battery pack and the intermediate circuit capacitor, wherein theelectrical system has a galvanically isolated DC/DC converter that is connected to a voltage source in the electrical system, wherein the DC/DC converter is configured such that it can transmit electric energy to a high-voltage side with the intermediate circuit capacitor in order to pre-charge the intermediate circuit capacitor, wherein the electrical system has a diagnostic device to test the power relays, wherein the