CN210629185U

CN210629185U - Power supply system of automobile EPS

Info

Publication number: CN210629185U
Application number: CN201921412274.6U
Authority: CN
Inventors: 向坤; 刘培培; 张双杰; 刘伟; 苏本罡
Original assignee: Anhui Defu Steering System Inc
Current assignee: China Highway Vehicle and Machinery Co Ltd
Priority date: 2019-08-28
Filing date: 2019-08-28
Publication date: 2020-05-26
Anticipated expiration: 2029-08-28

Abstract

The utility model discloses a power supply system of an automobile EPS, which comprises a high-voltage power supply branch and a low-voltage boosting power supply branch, wherein the high-voltage power supply branch is connected with the anode of a diode D1, and the cathode of a diode D1 is connected with the power supply input end of the EPS; the low-voltage boosting power supply branch circuit is connected with the anode of a diode D2, the cathode of a diode D2 is connected with the power supply input end of the EPS, and a voltage difference is arranged between the output voltage of the high-voltage power supply branch circuit and the output voltage of the low-voltage boosting power supply branch circuit. The utility model has the advantages that: the power supply of the EPS can be ensured when one power supply fails through the high-voltage and low-voltage power supply, so that the EPS outputs power continuously, and accidents caused by sudden disappearance of the power are avoided; one of the two paths is automatically switched to supply power through the diodes D1 and D2, no switching delay exists, the power-off time of the power supply is 0, and the duration of the power assistance is ensured.

Description

Power supply system of automobile EPS

Technical Field

The invention relates to the field of electric vehicle steering power assistance, in particular to a power supply system of an electric vehicle EPS.

Background

The EPS system of the electric vehicle needs to supply power for work, and the power supply used for driving the motor comprises a high-voltage power supply with DC about 200-650V and a 12V or 24V voltage power supply for auxiliary use. The EPS system operates using one of the power sources. Therefore, when the voltage of the power supply is lowered and the wire harness is broken and the contact of the connector is poor, the assist force is stopped and the steering is not performed. When the assist force is stopped, the assist force of the steering wheel disappears immediately, which causes difficulty in steering and is likely to cause an accident.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a power supply system of an electric vehicle EPS, which is used for ensuring the power supply of a steering power-assisted system to a certain extent.

In order to achieve the purpose, the invention adopts the technical scheme that: a power supply system of an electric vehicle EPS comprises a high-voltage power supply branch and a low-voltage boosting power supply branch, wherein the high-voltage power supply branch is connected with the anode of a diode D1, and the cathode of a diode D1 is connected with the power supply input end of the EPS; the low-voltage boosting power supply branch circuit is connected with the anode of a diode D2, the cathode of a diode D2 is connected with the power supply input end of the EPS, and a voltage difference is arranged between the output voltage of the high-voltage power supply branch circuit and the output voltage of the low-voltage boosting power supply branch circuit.

Further, the low-voltage boost power supply branch comprises a low-voltage power supply and a DCDC boost module, and the low-voltage power supply is connected with the anode of the diode D2 through the DCDC boost module.

Further, the high-voltage power supply branch comprises a 400V output high-voltage power supply.

Further, the control unit ECU of the EPS is connected with a voltage sensor, and the voltage sensor is used for collecting voltage signals of an EPS power supply input end.

Further, the output end of the ECU is connected with a low-voltage power supply alarm module.

Further, the ECU of the EPS controls the power assisting size output by the EPS system according to the signal collected by the voltage sensor; and when the power supply of the low-voltage boosting power supply branch is detected, controlling the EPS to output the assistance smaller than the assistance output when the high-voltage power supply branch is used.

Further, the low-voltage power supply is a 12V or 24V power supply output by a low-voltage bus in the vehicle.

Further, the ECU controls the magnitude of the output power assistance by adjusting the magnitude of the power supply current of the steering motor.

The invention has the advantages that: the power supply of the EPS can be ensured when one power supply fails through the high-voltage and low-voltage power supply, so that the EPS outputs power continuously, and accidents caused by sudden disappearance of the power are avoided; one of the two paths is automatically switched to supply power through the diodes D1 and D2, no switching delay exists, the power-off time of the power supply is 0, and the duration of the power assistance is ensured.

Drawings

The contents of the expressions in the various figures of the present specification and the labels in the figures are briefly described as follows:

fig. 1 is a schematic diagram of the power supply system of the present invention.

Detailed Description

The following description of preferred embodiments of the invention will be made in further detail with reference to the accompanying drawings.

The power supply mode among the prior art adopts the power supply all the way (400V high voltage power supply bus power supply), breaks down or the pencil breaks, phenomenon such as grafting contact failure directly can cut off the power supply line, at the stop work that becomes the EPS system, stops the helping hand, causes the resistance of steering wheel to strengthen, seriously influences the experience of driving, and still probably cause the direction to be difficult to rotate and cause some accidence development, based on this, the technical scheme of this application provides a power supply circuit system of EPS, specifically as follows:

as shown in fig. 1, a power supply system of an electric vehicle EPS comprises a high-voltage power supply branch and a low-voltage boosting power supply branch, wherein the high-voltage power supply branch is connected with the anode of a diode D1, and the cathode of a diode D1 is connected with a power supply input end of the EPS; the low-voltage boosting power supply branch is connected with the anode of a diode D3D 2, the cathode of a diode D2 is connected with the power supply input end of the EPS, and a voltage difference is set between the output voltage of the high-voltage power supply branch and the output voltage of the low-voltage boosting power supply branch. The example that the output voltage of the high-voltage power supply branch is greater than the output voltage of the low-voltage boosting branch is taken as an example for explanation. When the high-voltage power supply branch and the low-voltage boosting power supply branch both normally output power supply, the voltage output by the high-voltage power supply branch is greater than the output voltage of the low-voltage boosting power supply branch, so that under the action of the diodes D1 and D2 and the action of reverse non-conduction of D2, the high-voltage power supply branch can only supply power for the EPS through the power supply input end, and assistance is provided. When the high-voltage power supply branch circuit is broken and the plug wire part is in poor contact, the voltage output by the high-voltage power supply branch circuit is reduced or is 0, and the voltage output by the low-voltage boosted circuit is greater than that of the high-voltage power supply branch circuit, so that the low-voltage boosted power supply branch circuit can immediately supply power for the EPS (electric power storage) circuit, and due to the reverse non-conduction effect of the diode D1, the power supply voltage of the low-voltage boosted power supply branch circuit cannot be transmitted to the high-voltage branch circuit, and the influences. Because the diodes D1 and D2 are adopted to automatically switch one of the two paths to supply power, no relay or other devices are adopted to switch, when one path fails, the other path is quickly switched to supply power, no time delay exists, the EPS power supply and power failure time is 0, and the EPS is ensured to supply power all the time to provide assistance for power supply work.

The power is supplied through two paths of the high-voltage power supply branch and the low-voltage boosting power supply branch, and the other path is quickly and automatically switched to work after one path is powered off, so that the power supply of the EPS is ensured. In a preferred embodiment, the high-voltage power supply branch comprises a 400V high-voltage power supply which is high-voltage power output by a high-voltage bus of the whole vehicle, the power supply exists in an EPS power supply system of the whole vehicle, and a low-voltage boosting power supply branch is added on the basis of the power supply, and comprises a low-voltage power supply and a DCDC boosting module, wherein the low-voltage power supply is connected with the anode of the diode D2 through the DCDC boosting module. The low-voltage power supply adopts a voltage output by a 12V low-voltage bus or a 24V low-voltage bus in a whole vehicle system as a power supply, and in order to meet the requirement that the EPS provides power for a steering motor, 2V voltage is boosted to a preset voltage value, such as 220V, through a DCDC converter. The 12V voltage and 24V power supply is a low-voltage power supply existing in the whole vehicle, and the power supply is connected to the DCDC converter through a wire during implementation. Therefore, the power supply of the EPS power supply input end comprises a 400V voltage power supply and a 220V voltage power supply (the voltage difference set by the two is 180V), one of the two is automatically selected to supply power to the EPS due to reverse non-conduction of the diodes D1 and D2, and then the EPS system provides assistance according to the rotation of the power supply drive control steering motor.

In another preferred embodiment, the power supply supplies the high-voltage power supply branch in normal operation, and the high-voltage power supply branch is switched into a low-voltage boosting power supply branch serving as a standby power supply branch under the action of a diode when the high-voltage power supply branch fails. In order to give a prompt after a fault of a high-voltage power supply branch, a voltage transformer is adopted to collect the voltage value of an EPS power supply input end, the output end of the voltage transformer is connected with an ECU (electronic control unit) of an EPS, the ECU judges which branch of the power supply at the moment is (when the detected power supply voltage is 400V, the branch of the high-voltage power supply is, and if the detected voltage is 220V, the branch of the low-voltage boosting power supply is), when the branch of the low-voltage boosting power supply is in, the high-voltage power supply fault needs to give an alarm, the ECU of the EPS is connected with an alarm unit at the moment for giving an alarm, so that a user can timely maintain and check the power, and the low-voltage power supply branch can give 220V power supply with certain power. The alarm unit adopts an alarm, an indicator light or a display screen on a vehicle instrument panel to display related alarms, the ECU is connected with the vehicle controller through a CAN bus, and then the vehicle body controller outputs and controls the alarm, the indicator light and the display screen to give display signals.

In another preferred embodiment, when the ECU of the EPS determines to supply power to the low-voltage boost power supply branch according to the voltage signal collected by the voltage sensor, the ECU controls the output power assistance of the EPS to be smaller than the output power assistance provided by the high-voltage power supply branch during normal operation. When the ECU is in the low-voltage boosting branch circuit for supplying power, the current output to the steering motor by the EPS is controlled to control the output power assistance. For example, when the low-voltage boosting branch is used for supplying power, the auxiliary power is required to be reduced due to the fact that the low-voltage boosting branch is used for standby power supply, the auxiliary power is changed to be 50% or 80% of the auxiliary power in the original normal high-voltage power supply, and the rotation of the steering motor can be controlled by controlling the current output to the steering motor by the EPS so as to control the size of the auxiliary power. Therefore, on one hand, the power assisting is kept continuous, and on the other hand, the user feels the change of the power assisting to remind the user of paying attention and overhauling in time; while reducing battery consumption.

On prior art's basis, this application has increased a low pressure power supply branch to and be used for controlling diode D1, D2 that two branches switch, high-voltage power supply is the power supply of the same way among the prior art, and the low pressure power supply branch that increases draws out 12V or 24V power through whole car low voltage bus or battery, then steps up through the DCDC converter. Through the improvement to prior art, thereby increase low pressure branch road and D1, D2 and realized the power supply protection to the EPS, promote and continuously supply power and helping hand output ability. The EPS of the whole vehicle is guaranteed to be switched in time and continuously powered when the high-voltage power supply fails, and disappearance of the power assistance is avoided.

In the prior art, when a high-voltage power supply is used, the EPS must stop working when the power supply is powered off. The high-voltage end and the 12V/2V low-voltage end of the EPS are boosted to DC220V by a DC-DC converter to form a two-way system power supply. In general, when the high-voltage side is operated and the voltage of the high-voltage side is lowered, a power supply boosted from a low voltage is used. The action of switching the power supply is not needed, the power-off time of the power supply is zero, the EPS continuously works, the power assistance is continuously stable, and the EPS does not disappear suddenly. In addition, 2 power supply systems are provided with voltage differences, when the low-voltage end works, the maximum value of the power assistance is limited to 50% of the output power assistance when the high-voltage end works, and the battery consumption is reduced. Therefore, when the voltage of any party is powered off, the EPS can continuously work. (disconnection of the wire harness, redundancy in the case of defective contact of the connector.) therefore, the stop assist force which may be dangerous during traveling can be avoided. In addition, when the high-voltage end is powered off, the boosting is limited to 50% when the low-voltage end works, the consumption of a low-voltage battery can be limited, and the boosting can be continuously performed for a long time.

It is clear that the specific implementation of the invention is not restricted to the above-described embodiments, but that various insubstantial modifications of the inventive process concept and technical solutions are within the scope of protection of the invention.

Claims

1. The utility model provides a power supply system of car EPS, includes high voltage power supply branch road, its characterized in that: the high-voltage power supply branch circuit is connected with the anode of a diode D1, and the cathode of a diode D1 is connected with the power supply input end of the EPS; the low-voltage boosting power supply branch circuit is connected with the anode of a diode D2, the cathode of a diode D2 is connected with the power supply input end of the EPS, and a voltage difference is arranged between the output voltage of the high-voltage power supply branch circuit and the output voltage of the low-voltage boosting power supply branch circuit.

2. The power supply system of an automotive EPS according to claim 1, characterized in that: the low-voltage boosting power supply branch comprises a low-voltage power supply and a DCDC boosting module, and the low-voltage power supply is connected with the anode of the diode D2 through the DCDC boosting module.

3. The power supply system of an automotive EPS according to claim 1, characterized in that: the high-voltage power supply branch comprises a 400V output high-voltage power supply.

4. A power supply system of an EPS of an automobile according to any one of claims 1 to 3, characterized in that: and the control unit ECU of the EPS is connected with a voltage sensor, and the voltage sensor is used for acquiring a voltage signal of an EPS power supply input end.

5. The power supply system of an EPS of an automobile according to claim 4, wherein: and the output end of the ECU is connected with the low-voltage power supply alarm module.

6. The power supply system of an EPS of an automobile according to claim 4, wherein: the ECU of the EPS controls the power assisting size output by the EPS system according to the signal acquired by the voltage sensor; and when the power supply of the low-voltage boosting power supply branch is detected, controlling the EPS to output the assistance smaller than the assistance output when the high-voltage power supply branch is used.

7. The power supply system of an automotive EPS according to claim 2, characterized in that: the low-voltage power supply is a 12V or 24V power supply output by a low-voltage bus in the vehicle.

8. The power supply system of an EPS of an automobile according to claim 6, characterized in that: the ECU controls the output power assistance by adjusting the power supply current of the steering motor.