Vehicle electrical system and vehicle with such a vehicle electrical system

Abstract

The invention relates to a vehicle electrical system (12), comprising: a power distribution unit (18); a first DC-DC converter (22) which can be connected to the power distribution unit (18) and to a high-voltage battery (14) of the vehicle (10) and is designed to convert a high-voltage voltage provided by the high-voltage battery (14) into a first low-voltage vehicle electrical system voltage; a second DC-DC converter (26) which can be connected to the high-voltage battery (14) and is connectable or connected to the power distribution unit (18) and is designed to convert the high-voltage voltage provided by the high-voltage battery (14) into a second low-voltage vehicle electrical system voltage which lies in a range below the first low-voltage vehicle electrical system voltage;and a control unit (28) which is connected to the energy distribution unit (18) and is designed to supply low-voltage consumers (16) of the vehicle electrical system (12) by means of the first low-voltage vehicle electrical system voltage in a first vehicle state, and to supply the low-voltage consumers (16) only by means of the second low-voltage vehicle electrical system voltage in a second vehicle state;

Claims

[1] Vehicle electrical system (12) for an electric vehicle (10), comprising: - a power distribution unit (18) for distributing electrical energy within the vehicle electrical system (12), - a first DC-DC converter (22) which can be connected to the energy distribution unit (18) and to a high-voltage battery (14) of the vehicle (10), wherein the first DC-DC converter (22) is designed to convert a high-voltage voltage provided by the high-voltage battery (14) of the vehicle into a first low-voltage vehicle electrical system voltage which is in a range from 24V to 60V, - a second DC-DC converter (26) which is connectable to the high-voltage battery (14) of the vehicle (10) and is connectable or connected to the energy distribution unit (18), wherein the second DC-DC converter (26) is designed to convert the high-voltage voltage provided by the high-voltage battery (14) into a second low-voltage vehicle electrical system voltage which is in a range below the first low-voltage vehicle electrical system voltage and in particular in a range from 5V to 16V, and - a control unit (28) connected to the power distribution unit (18) and designed to - in a first vehicle state, in particular a driving operation of the vehicle (10), to make the first low-voltage vehicle electrical system voltage provided by the first DC-DC converter (22) available to low-voltage consumers (16) of the vehicle electrical system (12), and - in a second vehicle state, in particular a parking mode of the vehicle (10), to make only the second low-voltage vehicle electrical system voltage provided by the second DC-DC converter (26) available to the low-voltage consumers (16), wherein the low-voltage consumers (16) are each connected to a converter (33) which has a half-bridge (36) with a high-side transistor circuit (38) and a low-side transistor circuit (40), wherein the converter (33) optionally keeps the first low-voltage vehicle electrical system voltage or the second low-voltage vehicle electrical system voltage available for supplying the low-voltage consumers (16) by appropriate control by the control unit (28), and wherein the control unit (28) is further designed to - in the first vehicle state, to control the high-side transistor circuit (38) and the low-side transistor circuit (40) such that the low-voltage consumers (16) can only be supplied with the first low-voltage vehicle electrical system voltage, and - in the second vehicle state, to open the low-side transistor circuit (40) and to close the high-side transistor circuit (38) so that the low-voltage consumers (16) can only be supplied with the second low-voltage vehicle electrical system voltage. [2] Vehicle electrical system (12) according to claim 1, wherein the second DC-DC converter (26) is connected to the energy distribution unit (18) by means of a diode (34), the second DC-DC converter (26) provides the second low-voltage vehicle electrical system voltage in both the first and the second vehicle state, and the diode (34) is designed such that in the first vehicle state, the first low-voltage vehicle electrical system voltage provided by the first DC-DC converter (22) is not applied to the second DC-DC converter (26) or no current flows into the second DC-DC converter (26). [3] Vehicle electrical system (12) according to claim 1 or 2, wherein the second DC-DC converter (26) is designed for a power of maximum 15 watts, preferably maximum 10 watts, more preferably maximum 5 watts. [4] Vehicle electrical system (12) according to one of claims 1 to 3, wherein the first DC-DC converter (22) is designed for a power of at least 1000 watts. [5] Vehicle electrical system (12) according to one of claims 1 to 4, wherein the energy distribution unit (18) has a switching device (24) which is designed as an electrical safety device and has a first, closed switching state and a second, open switching state, and wherein the control unit (28) is further designed to - that in the first vehicle state, the first switching state of the switching device (24) is set, and - that in the second vehicle state the second switching state of the switching device (24) is set. [6] Vehicle electrical system (12) according to one of claims 1 to 5, wherein the second DC-DC converter (26) is connected to the high-voltage battery (14) in such a way that the second DC-DC converter (26) provides the second low-voltage vehicle electrical system voltage in both the first and the second vehicle state. [7] Vehicle electrical system (12) according to one of claims 1 to 6, wherein the first DC-DC converter (22) is connected to the high-voltage battery (14) such that the first DC-DC converter (22) is active only in the first vehicle state. [8] Vehicle (10), in particular electric vehicle or electrically powered vehicle, with a vehicle electrical system (12) according to one of the preceding claims.

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