A control system and method for an on-board DC power supply and an automobile

Abstract

This invention provides a control system, method, and vehicle for an on-board DC power supply. The system includes: a first DC / DC converter and a second DC / DC converter electrically connected to a power battery; the first DC / DC converter is electrically connected to the battery via a first transistor; the second DC / DC converter is electrically connected to the battery via a second transistor; the first DC / DC converter and the second DC / DC converter are connected in parallel; a controller is electrically connected to the first DC / DC converter, the second DC / DC converter, the first transistor, and the second transistor, and is used to control the first DC / DC converter to stop working after determining that the first transistor has failed; and to control the second DC / DC converter to stop working after determining that the second transistor has failed. The solution of this invention can prevent the failure of one DC / DC converter from causing the failure of the entire low-voltage circuit, thus possessing a high level of safety.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, and also to a control system, method, and vehicle for an on-board DC power supply. Background Technology

[0002] The vehicle-mounted DC / DC (a device that converts electrical energy from one voltage value to another in a DC circuit) power supply converts the voltage of the electric vehicle's high-voltage power battery to a low voltage of 14V, charging the 14V low-voltage battery and simultaneously powering the vehicle's low-voltage control system.

[0003] With the increasing safety requirements of vehicles, the DC / DC parallel redundancy design is gradually being accepted. However, in the existing DC / DC parallel redundancy design, if a short circuit occurs in any of the DC / DC circuits, the entire low-voltage circuit will fail, and the DC / DC parallel redundancy design will not achieve the redundancy effect. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a control system, method and vehicle for an on-board DC power supply, which can prevent the failure of the entire low-voltage circuit when one of the DC / DC converters fails, and has a high level of safety.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] A control system for an on-board DC power supply, comprising:

[0007] A first DC / DC converter and a second DC / DC converter electrically connected to the power battery;

[0008] The first DC / DC converter is electrically connected to the battery via a first transistor;

[0009] The second DC / DC converter is electrically connected to the battery via a second transistor;

[0010] The first DC / DC converter is connected in parallel with the second DC / DC converter;

[0011] The controller is electrically connected to the first DC / DC converter, the second DC / DC converter, the first transistor, and the second transistor, and is used to control the first DC / DC converter to stop working after determining that the first transistor has failed; and to control the second DC / DC converter to stop working after determining that the second transistor has failed.

[0012] Optionally, the voltage of the battery is a first target voltage.

[0013] Optionally, determining that the first transistor has failed includes:

[0014] When the output voltage of the second DC / DC converter is adjusted to the second target voltage, the first transistor is turned off. If the output voltage of the first DC / DC converter is the second target voltage, the first transistor is determined to be faulty, and the second target voltage is greater than the first target voltage.

[0015] Optionally, determining that the second transistor has failed includes:

[0016] When the output voltage of the first DC / DC converter is adjusted to the second target voltage, the second transistor is controlled to turn off. If the output voltage of the second DC / DC converter is the second target voltage, it is determined that the second transistor has failed. The second target voltage is greater than the first target voltage.

[0017] Optionally, the first output terminal of the first DC / DC converter is electrically connected to the input terminal of the first transistor, and the output terminal of the first transistor is electrically connected to the positive terminal of the battery.

[0018] The second output terminal of the first DC / DC converter is electrically connected to the negative terminal of the battery;

[0019] A first capacitor is also electrically connected between the first output terminal and the second output terminal of the first DC / DC converter.

[0020] Optionally, the first output terminal of the second DC / DC converter is electrically connected to the input terminal of the second transistor, and the output terminal of the second transistor is electrically connected to the positive terminal of the battery.

[0021] The second output terminal of the second DC / DC converter is electrically connected to the negative terminal of the battery;

[0022] A second capacitor is also electrically connected between the first output terminal and the second output terminal of the second DC / DC converter.

[0023] Embodiments of the present invention also provide a control method for an on-board DC power supply, applied to the control system of the on-board DC power supply as described above, the method comprising:

[0024] After determining that the first transistor has failed, control the first DC / DC converter to stop working;

[0025] Once the failure of the second transistor is determined, the second DC / DC converter is controlled to stop working.

[0026] Optionally, determining that the first transistor has failed includes:

[0027] When the output voltage of the second DC / DC converter is adjusted to the second target voltage, the first transistor is turned off. If the output voltage of the first DC / DC converter is the second target voltage, the first transistor is determined to be faulty. The second target voltage is greater than the first target voltage, and the voltage of the battery is the first target voltage.

[0028] Optionally, determining that the second transistor has failed includes:

[0029] When the output voltage of the first DC / DC converter is adjusted to the second target voltage, the second transistor is controlled to turn off. If the output voltage of the second DC / DC converter is the second target voltage, it is determined that the second transistor has failed. The second target voltage is greater than the first target voltage.

[0030] Embodiments of the present invention also provide an automobile, including: a power battery, and a control system for the on-board DC power supply as described above.

[0031] The above-described solution of the present invention has at least the following beneficial effects:

[0032] The above-described solution of the present invention uses a first DC / DC converter and a second DC / DC converter electrically connected to a power battery; the first DC / DC converter is electrically connected to the battery via a first transistor; the second DC / DC converter is electrically connected to the battery via a second transistor; the first DC / DC converter and the second DC / DC converter are connected in parallel; a controller is electrically connected to the first DC / DC converter, the second DC / DC converter, the first transistor, and the second transistor, and is used to control the first DC / DC converter to stop working after determining that the first transistor has failed; and to control the second DC / DC converter to stop working after determining that the second transistor has failed; thereby preventing the failure of one DC / DC converter from causing the failure of the entire low-voltage circuit, and providing a high level of safety. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the circuit structure of the control system of the vehicle-mounted DC power supply of the present invention.

[0034] Figure 2 This is a flowchart illustrating the control method of the vehicle-mounted DC power supply of the present invention. Detailed Implementation

[0035] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0036] like Figure 1 As shown, an embodiment of the present invention proposes a control system for an on-board DC power supply.

[0037] A first DC / DC converter and a second DC / DC converter are electrically connected to the power battery; here, the power battery is the high-voltage power battery of the vehicle.

[0038] The first DC / DC converter is electrically connected to the battery via a first transistor Q1; here, the battery is the low-voltage battery of the vehicle.

[0039] The second DC / DC converter is electrically connected to the battery via the second transistor Q2;

[0040] The first DC / DC converter and the second DC / DC converter are connected in parallel; specifically, the first input terminal of the first DC / DC converter is electrically connected to the positive terminal of the high-voltage power battery, and the second input terminal of the first DC / DC converter is electrically connected to the negative terminal of the high-voltage power battery; the first input terminal of the second DC / DC converter is electrically connected to the positive terminal of the high-voltage power battery, and the second input terminal of the second DC / DC converter is electrically connected to the negative terminal of the high-voltage power battery.

[0041] A controller (not shown in the figure) is electrically connected to the first DC / DC converter, the second DC / DC converter, the first transistor, and the second transistor. It is used to control the first DC / DC converter to stop operating after determining that the first transistor has failed; and to control the second DC / DC converter to stop operating after determining that the second transistor has failed. Here, the controller can be a control module in a battery management system (BMS) or a separate controller.

[0042] This embodiment utilizes a first DC / DC converter and a second DC / DC converter electrically connected to a power battery. The first DC / DC converter is electrically connected to the battery via a first transistor, and the second DC / DC converter is electrically connected to the battery via a second transistor. The first and second DC / DC converters are connected in parallel. A controller, electrically connected to the first and second DC / DC converters, the first transistor, and the second transistor, is used to control the first DC / DC converter to stop working after determining that the first transistor has failed; and to control the second DC / DC converter to stop working after determining that the second transistor has failed. This prevents the failure of one DC / DC converter from causing the entire low-voltage circuit to fail, thus providing a high level of safety.

[0043] In an optional embodiment of the invention, the voltage of the battery is a first target voltage. Here, the first target voltage is preferably 14V; used to provide power to the vehicle's low-voltage system.

[0044] In an optional embodiment of the present invention, the controller determining that the first transistor has failed may specifically include:

[0045] When the output voltage of the second DC / DC converter is adjusted to the second target voltage, the first transistor is turned off. If the output voltage of the first DC / DC converter is the second target voltage, the first transistor is determined to have failed. The second target voltage is greater than the first target voltage. Here, the second target voltage can be, for example, 15V, but is not limited to 15V, as long as it is greater than the first target voltage. Of course, in some special cases, the second target voltage can also be less than the first target voltage to determine whether the first transistor has failed.

[0046] In an optional embodiment of the present invention, the controller determines that the second transistor has failed, specifically including:

[0047] When the output voltage of the first DC / DC converter is adjusted to the second target voltage, the second transistor is turned off. If the output voltage of the second DC / DC converter is the second target voltage, the second transistor is determined to be faulty. The second target voltage is greater than the first target voltage. Here, the second target voltage can be, for example, 15V, but is not limited to 15V, as long as it is greater than the first target voltage. Of course, in some special cases, the second target voltage can also be less than the first target voltage to determine whether the first transistor has failed.

[0048] In an optional embodiment of the present invention, the first output terminal of the first DC / DC converter is electrically connected to the input terminal of the first transistor, and the output terminal of the first transistor is electrically connected to the positive terminal of the battery.

[0049] The second output terminal of the first DC / DC converter is electrically connected to the negative terminal of the battery;

[0050] A first capacitor C1 is also electrically connected between the first output terminal and the second output terminal of the first DC / DC converter.

[0051] In an optional embodiment of the present invention, the first output terminal of the second DC / DC converter is electrically connected to the input terminal of the second transistor, and the output terminal of the second transistor is electrically connected to the positive terminal of the battery.

[0052] The second output terminal of the second DC / DC converter is electrically connected to the negative terminal of the battery;

[0053] A second capacitor C2 is also electrically connected between the first output terminal and the second output terminal of the second DC / DC converter.

[0054] In the above embodiments of the present invention, in the parallel design of the first DC / DC converter (DC / DC1) and the second DC / DC converter (DC / DC2), when the two DC / DC converters work at the same time, the output voltage is 14V. If the output voltage of DC / DC1 is increased to 15V, the battery will also be charged to 15V. Since they are connected in parallel, the output of DC / DC2 will be clamped to 15V.

[0055] If Q2 is disconnected at this time, the actual setting value of DC / DC is 14V. Therefore, if Q2 is not faulty, the voltage at point B should be 14V. If it is 15V, it means that Q2 is short-circuited. In order to prevent DC / DC2 from failing due to internal short circuit, DC / DC2 should stop working and shut down for protection. The flowchart is shown in Figure (2).

[0056] Following the same principle, the diagnosis of Q1 is the same as that of Q2. If Q1 is disconnected at this time, the actual setting value of DC / DC is 14V. Therefore, if Q1 has not failed, the voltage at point A should be 14V. If it is 15V, it means that Q1 is short-circuited. In order to prevent DC / DC1 from failing due to internal short circuit, DC / DC1 should stop working and shut down for protection.

[0057] The method described in the above embodiments of the present invention, assuming that DC / DC1 and DC / DC2 are working in parallel while the electric vehicle is in motion, according to the diagnostic strategy in Figure (2), Q1 and Q2 are diagnosed in real time. When Q1 is diagnosed as failing, DC / DC1 stops working, and when Q2 is diagnosed as failing, DC / DC2 stops working. This can prevent potential short circuit failure caused by the continued operation of DC / DC in the event of a short circuit failure of Q1 or Q2, which could lead to a short circuit in the low-voltage power supply system of the whole vehicle, thus possessing a high level of functional safety.

[0058] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for an on-board DC power supply, characterized in that, Control systems applied to vehicle-mounted DC power supplies include: A first DC / DC converter and a second DC / DC converter electrically connected to the power battery; The first DC / DC converter is electrically connected to the battery via a first transistor; The second DC / DC converter is electrically connected to the battery via a second transistor; The first DC / DC converter is connected in parallel with the second DC / DC converter; The controller, electrically connected to the first DC / DC converter, the second DC / DC converter, the first transistor, and the second transistor, is used to control the first DC / DC converter to stop working after determining that the first transistor has failed; and to control the second DC / DC converter to stop working after determining that the second transistor has failed. The voltage of the battery is the first target voltage; Determining that the first transistor has failed includes: When the output voltage of the second DC / DC converter is adjusted to the second target voltage, the first transistor is controlled to turn off. If the output voltage of the first DC / DC converter is the second target voltage, it is determined that the first transistor has failed. The second target voltage is greater than the first target voltage. Determining that the second transistor has failed includes: When the output voltage of the first DC / DC converter is adjusted to the second target voltage, the second transistor is controlled to turn off. If the output voltage of the second DC / DC converter is the second target voltage, the second transistor is determined to be faulty. The second target voltage is greater than the first target voltage. The first output terminal of the first DC / DC converter is electrically connected to the input terminal of the first transistor, and the output terminal of the first transistor is electrically connected to the positive terminal of the battery. The second output terminal of the first DC / DC converter is electrically connected to the negative terminal of the battery; A first capacitor is also electrically connected between the first output terminal and the second output terminal of the first DC / DC converter. The first output terminal of the second DC / DC converter is electrically connected to the input terminal of the second transistor, and the output terminal of the second transistor is electrically connected to the positive terminal of the battery. The second output terminal of the second DC / DC converter is electrically connected to the negative terminal of the battery; A second capacitor is also electrically connected between the first and second output terminals of the second DC / DC converter. The method includes: Once the first transistor is determined to be faulty, the first DC / DC converter is controlled to stop working. Once the failure of the second transistor is determined, the second DC / DC converter is controlled to stop working.

Images