NOVELTY - The system (11) has an electronic power converter (15) for presenting positive and negative poles (21, 23) that are connected to a low voltage storage system (14) through a two-pole electrical cable (18). An electronic control unit (17) controls the electronic power converter and including positive and negative poles (24, 25) that are connected to the low voltage storage system through another cable (19). The negative pole of the electronic power converter is connected to the negative pole of the electronic control unit only through an impedance having value not lower than 100 Ohm.    USE - Electrical system for an electrical traction vehicle e.g. hybrid electrical and thermal vehicle.    ADVANTAGE - The system is simple and cost-effective. The system preserves a functionality of electronic microprocessor control units and then DC/AC power converter in case of undesired interruption of a connection between the negative pole of the low voltage storage system and the negative pole of the DC/DC power converter. The system guarantees an integrity with different installation on the vehicle and a wiring connection such a result is guaranteed by limiting a maximum current, which is circulated through the electrical cable having small section in case of problems in the electrical cable having large section. The electronic microprocessor control units are immune from electromagnetic interferences present on the vehicle, which generates currents induced in the negative poles and damage the printed circuit of the electronic microprocessor control units.    DETAILED DESCRIPTION - The electronic power converter is a bi-directional direct current (DC)/alternate current (AC) electronic power converter such as inverter/rectifier.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of an electrical power system of a vehicle.    Electrical system (11)    Low voltage storage system (14)    Electronic power converter (15)    Electronic control unit (17)    Two-pole electrical cables (18, 19)    Positive and negative poles (21, 23, 24, 25)