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CN-116054576-B - Energy system for electric vehicle

CN116054576BCN 116054576 BCN116054576 BCN 116054576BCN-116054576-B

Abstract

The present invention relates to an energy system for an electric vehicle. The electric vehicle has at least one high-voltage on-board network and at least one low-voltage on-board network, wherein the system comprises a high-voltage battery which is connected to the at least one high-voltage on-board network by means of an interruption element, wherein the high-voltage battery comprises a first branch and a second branch connected in series, wherein a first input module of the DC/DC converter is connected to the first branch, the first input module comprises a high-voltage bridge and is connected to a first primary winding of a transformer having two primary windings and a common secondary winding, a second input module of the DC/DC converter is connected to the second branch, the second input module comprises a high-voltage bridge and is connected to a second primary winding of a transformer having two primary windings and a common secondary winding, and an output of the DC/DC converter is connected to the at least one low-voltage on-board network. The invention further relates to a method for supplying electrical energy to a vehicle.

Inventors

  • WILDGRUBER MARIO

Assignees

  • 奥迪股份公司

Dates

Publication Date
20260512
Application Date
20220824
Priority Date
20211028

Claims (10)

  1. 1.A system (100) for supplying electric energy to an electric vehicle having at least one high voltage on-board network and at least one low voltage on-board network, wherein the system (100) comprises a high voltage battery (10) connected to the at least one high voltage on-board network by means of an interruption element, wherein the high voltage battery (10) comprises a first branch (11) and a second branch (12) connected in series, wherein a first input module (21) of a DC/DC converter (20) is connected to the first branch (11), the first input module comprising a high voltage bridge and being connected to a first primary winding of a transformer (23) having two primary windings and a common secondary winding, a second input module (22) of the DC/DC converter (20) being connected to the second branch (12), the second input module comprising a high voltage bridge and being connected to a second primary winding of a transformer (23) having two primary windings and a common secondary winding, the DC/DC converter (20) output being connected to the at least one low voltage on-board network.
  2. 2. The system according to claim 1, wherein the high voltage bridge of the first input module (21) and the second input module (22) is implemented as a full bridge.
  3. 3. The system according to claim 1, wherein the high voltage bridge of the first input module (21) and the second input module (22) is implemented as a half bridge.
  4. 4. The system according to claim 1, wherein the high voltage bridge of the first input module (21) and the second input module (22) is implemented as a resonant converter.
  5. 5. The system according to any one of claims 1 to 4, wherein the DC/DC converter (20) has an active or passive rectifier on the secondary side of the transformer (23).
  6. 6. The system according to any one of claims 1 to 4, wherein the DC/DC converter (20) has an active full bridge at the secondary side of the transformer (23).
  7. 7. The system according to any one of claims 1 to 4, wherein the DC/DC converter (20) has a current multiplier on the secondary side of the transformer (23).
  8. 8. The system according to any one of claims 1 to 4, wherein the secondary winding of the transformer (23) has an intermediate tap, the DC/DC converter (20) using the intermediate tap on the secondary side of the transformer (23).
  9. 9. Method for supplying electric energy to an electric vehicle having at least one high-voltage on-board network and at least one low-voltage on-board network and comprising a high-voltage battery (10) comprising a first branch (11) and a second branch (12) connected in series, wherein the at least one high-voltage on-board network is connected to an electrode of the high-voltage battery (10) and supplied with electric energy, and the at least one low-voltage on-board network is connected to an output of a DC/DC converter (20) in which a first input module (21) with a high-voltage bridge is connected to the first branch (11) and a second input module (22) with a high-voltage bridge is connected to the second branch (12), wherein each of the two input modules (21, 22) is connected to one primary winding of a transformer (23) having two primary windings and a common secondary winding.
  10. 10. Method according to claim 9, wherein in case of a failure of the first branch (11) the total power is output to the low voltage on-board network by the second branch (12) and in case of a failure of the second branch (12) the total power is output to the low voltage on-board network by the first branch (11).

Description

Energy system for electric vehicle Technical Field The present invention relates to a system for supplying electric energy to a vehicle and a method for supplying electric energy to a vehicle. Background In today's electrically driven vehicles, such as plug-in hybrid vehicles (PHEV), electric only vehicles (BEV) or hybrid vehicles (HEV) equipped with a high voltage energy store (high voltage battery), a direct current converter (DC/DC converter) is used to power a low voltage on-board network (low voltage on-board network). The DC/DC converter is mainly powered by a high voltage battery and is connected to the full system voltage after the battery contactors. Today, these high voltage networks are not constrained by any ASIL safety classification and are therefore only conditionally applicable, or are not applicable at all for use with highly automated driving assistance systems, depending on the type. KR 101 548 B1 relates to a DC/DC converter. The DC/DC converter includes a switching unit that alternately switches DC input power, a transforming unit that includes a single transformer having a primary winding and a secondary winding, converts power input into the primary winding and outputs the converted power to a secondary winding side, a rectifying unit that includes a switching element and first to fourth diodes and operates according to operation of the switching element in a high-voltage mode or a low-voltage mode, and an output filter that filters power output from the rectifying unit. JP 2008/005685A describes a DC-DC converter having a circuit structure in which a single-winding transformer commonly forming a part of windings between a primary winding and a secondary winding is used to apply a voltage (which is distributed according to a winding ratio) to a synchronous rectification switch when a main switch is in an on state, so as to prevent an input voltage from being directly applied to the synchronous rectification switch. Thus, an element having a lower breakdown voltage than the input voltage can be used for the synchronous rectification switch, thereby reducing conduction loss and improving the efficiency of the DC-DC converter. Disclosure of Invention The object of the present invention is therefore to reliably supply an electric vehicle with electric energy to a low-voltage on-board network, which also meets the safety standards for highly automated driving assistance systems. This object is achieved by a system and a method having the following features. The subject of the invention is a system for supplying electric energy to an electric vehicle having at least one high-voltage on-board network and at least one low-voltage on-board network. The system comprises a high-voltage battery connected to the at least one high-voltage on-board network by an interruption element, wherein the high-voltage battery comprises a first branch and a second branch connected in series, wherein a first input module of a DC/DC converter is connected to the first branch, the first input module comprises a high-voltage bridge and is connected to a first primary winding of a transformer having two primary windings and a common secondary winding, a second input module of the DC/DC converter is connected to the second branch, the second input module comprises a high-voltage bridge and is connected to a second primary winding of a transformer having two primary windings and a common secondary winding, and an output of the DC/DC converter is connected to the at least one low-voltage on-board network. In the context of the present description, a high-voltage on-board network is a high-voltage on-board network having a voltage level exceeding 200V, in particular in the range from 300V to 1200V, for example 400V or 800V. The high-voltage battery is a high-voltage energy store with a nominal output voltage in the range of 300V to 1200V, for example 400V or 800V. The low-voltage on-board network is a low-voltage on-board network having a voltage level of less than 100V, in particular in the range of 10V to 60V, for example 12V or 48V. The system according to the invention is configured for supplying electric energy to an electric vehicle, wherein the vehicle has a plurality of electrical components (typically a consumer or a power source). The system is arranged in a vehicle and has a high-voltage battery or accumulator with two or more lines connected in series, each having at least one energy storage unit. Each line has at least one energy storage unit, for example a battery unit, wherein a plurality of energy storage units can be connected to one another in series and/or in parallel in the respective line. The poles of the high-voltage battery are connected via an interruption element (e.g. a battery contactor) to a high-voltage on-board network of the vehicle, which comprises a high-voltage unit of the vehicle, for example an electric motor for driving, heating and cooling the unit, and a charging module for ac-cu