Risk control method and system for vehicle low-voltage system

Abstract

The present application belongs to the electric vehicle technical field, disclose a kind of risk management and control method and system of vehicle low-voltage system, including battery state acquisition module, whole vehicle controller and power control module;Different state threshold is set for different power mode;The state parameters of low-voltage battery are collected in real time, if current state parameter exceeds the state threshold under current power mode, then risk early warning is carried out.The present application sets corresponding state threshold and control measure starting rule for each power mode respectively, more comprehensive control each power consumption link, improve power consumption safety and economy.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric vehicles, and particularly relates to a risk management and control method and system for a vehicle low-voltage system. BACKGROUND

[0002] At present, the power battery of a pure electric vehicle has a relatively perfect thermal runaway management scheme, but the low-voltage system mostly follows the scheme of a traditional fuel vehicle, which is relatively simple and does not need a complex thermal runaway system. With the development of pure electric vehicles into intelligent vehicles, the low-voltage system of a vehicle becomes more and more large, and the use scenarios of a vehicle in a non-starting state also become more and more rich, such as a sentinel mode, an intelligent power supplement mode, and early warning data uploading when parking, which also leads to a larger power supply demand of the low-voltage system and a more complex power supply mode. The traditional "turning key" type mechanical control power supply cannot meet the demand, and even if a vehicle model with a keyless one-key starting function is added, it only meets the logical control of the power supply gear. If there is a logical loophole (such as a long-term ON gear without high voltage), a misoperation behavior (such as a grounding misoperation), or a quality problem of an electric appliance (such as a controller not hibernating), there is a risk of thermal runaway of the low-voltage power supply voltage, current, and temperature, which leads to a risk of low-voltage battery depletion and even a fire vehicle (there are many cases of fire vehicles caused by low-voltage systems).

[0003] The prior art often warns the thermal runaway risk of the low-voltage system based on a single current threshold, which cannot meet the thermal runaway demand of various vehicle use scenarios, only considers the current, is too one-sided, and cannot reasonably reflect the low-voltage power supply state. SUMMARY

[0004] The purpose of the present application is to solve the problems existing in the prior art, and to provide a risk management and control method for a vehicle low-voltage system, which can timely warn in various vehicle use scenarios.

[0005] The present application is realized by the following technical scheme: a risk management and control method for a vehicle low-voltage system, different state thresholds are set for different power supply modes; the state parameters of a low-voltage storage battery are collected in real time, and if the current state parameters exceed the state threshold of the current power supply mode, a risk warning is performed.

[0006] Further, the state parameters include current, voltage, temperature, SOC value, and SOH value.

[0007] Further, when the state parameters exceed the state threshold and the duration exceeds a preset time length, a control measure is performed.

[0008] Further, the power supply mode includes five key gear positions: ON gear, ACC gear, OFF gear, hibernation gear, and deep hibernation gear.

[0009] Further, in OFF mode, hibernate mode or deep hibernate mode, if the current is greater than the corresponding state threshold and the duration exceeds the first preset time length, the low-voltage battery is disconnected, and the high-voltage battery is controlled to charge the low-voltage battery.

[0010] Further, in OFF mode, hibernate mode or deep hibernate mode, if the voltage or SOH value is lower than the corresponding state threshold and the duration exceeds the first preset time length, the low-voltage battery is disconnected, and the high-voltage battery is controlled to charge the low-voltage battery.

[0011] Further, when the SOC value is lower than the SOC state threshold, high-power constant-current charging is performed; when the SOC value is higher than the SOC state threshold, low-power constant-voltage charging is performed.

[0012] Further, in ON mode or ACC mode, if the current exceeds the corresponding state threshold and the temperature continues to rise for more than a preset time length, the low-voltage battery is actively disconnected.

[0013] Further, the maximum voltage threshold, the maximum current threshold and the highest temperature threshold of all power supply modes are set, and when any one of the corresponding state parameters exceeds the maximum voltage threshold, the maximum current threshold or the highest temperature threshold and the duration exceeds the second preset time length, the low-voltage battery is disconnected.

[0014] The application also provides a risk management and control system for a low-voltage system of a vehicle, characterized in that it comprises a battery state acquisition module, a vehicle controller and a power supply control module.

[0015] The battery state acquisition module is used to acquire state parameters of the low-voltage battery in real time.

[0016] The vehicle controller is used to determine the current power supply mode according to the vehicle signal and send it to the power supply control module.

[0017] The power supply control module comprises a condition setting unit, a risk warning unit, a power supply mode switching unit and a power supply opening and closing control unit.

[0018] The condition setting unit is used to set different state thresholds and control measure starting rules for different power supply modes.

[0019] The risk warning unit is used to determine whether the current state parameter exceeds the state threshold in the current power supply mode and whether the control measure needs to be started.

[0020] The power supply opening and closing control unit is used to disconnect or connect the low-voltage battery.

[0021] Further, a DC-DC converter is further included, and the high-voltage power supply charges the low-voltage battery through the DC-DC converter.

[0022] Compared with the prior art, the beneficial effects of the present application include:

[0023] 1. The prior art does not distinguish between power supply modes, and sets a single current threshold for thermal runaway risk warning. However, the present application considers that the allowed current or voltage range under different power supply modes is different, and the risks existing in different power supply modes are also different. The present application sets corresponding state thresholds and control measure starting rules for each power supply mode, more comprehensively controls each power consumption link, and improves the safety and economy of power consumption.

[0024] 2. Thermal runaway risk is more likely to occur in ON or ACC modes. The risk is judged by comprehensively considering current, temperature and duration, which is more accurate and helps to improve system stability.

[0025] 3. The risk of power loss is more likely to occur in OFF, sleep or deep sleep modes. The risk is judged by comprehensively considering current and duration, which is more accurate and helps to improve system stability. In order to ensure that the low-voltage battery has sufficient power when used in ACC mode, if the voltage or SOH value is lower than the corresponding state threshold and the duration exceeds the first preset time in OFF, sleep or deep sleep modes, the high-voltage battery is controlled to charge the low-voltage battery.

[0026] 4. Different charging modes are selected according to SOC, taking into account charging efficiency and safety.

[0027] 5. By disconnecting the low-voltage battery control measure, it can avoid the waste caused by continuous consumption of electric energy, and avoid the risk of fire caused by continuous overcurrent.

[0028] 6. Setting the maximum voltage threshold, maximum current threshold and maximum temperature threshold for all power supply modes can effectively avoid the risk caused by misoperation of connecting large voltage. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is an architectural diagram of a risk control system for a vehicle low-voltage system.

[0030] Figure 2 It is a flowchart.

[0031] Figure 3 It is a power supply mode switching diagram. DETAILED DESCRIPTION

[0032] The present application will be described in further detail below with reference to the accompanying drawings:

[0033] A risk management method of a vehicle low-voltage system is provided, wherein different state thresholds are set for different power supply modes; state parameters of a low-voltage storage battery are collected in real time, and the state parameters include current, voltage, temperature, SOC value and SOH value; and if the current state parameters exceed the state threshold of the current power supply mode, a risk warning is performed.

[0034] To realize the risk management method of the vehicle low-voltage system, as shown in Figure 1 , a risk management system of a vehicle low-voltage system is adopted, which comprises a storage battery state collection module, a vehicle controller and a power supply control module; the storage battery state collection module, the vehicle controller and the power supply control module are connected in communication through a CAN bus.

[0035] The storage battery state collection module is used to collect state parameters of a low-voltage storage battery in real time; the storage battery state collection module comprises a temperature sensor, a voltage sampling module, a current sampling module, an SOC value and SOH value estimation module.

[0036] The vehicle controller is used to determine the current power supply mode according to vehicle signals and send it to the power supply control module; the current power supply mode can be determined by key position or vehicle body state, CAN signal, self-timing, etc.

[0037] The power supply control module comprises a condition setting unit, a risk warning unit and a power supply on-off control unit.

[0038] The condition setting unit is used to set different state thresholds and management and control measure starting rules for different power supply modes.

[0039] The risk warning unit is used to determine whether the current state parameters exceed the state threshold of the current power supply mode and whether the management and control measures need to be started.

[0040] The power supply on-off control unit is used to disconnect or connect the low-voltage storage battery.

[0041] A DC-DC converter is further included, which is used to convert a high-voltage power supply into a low-voltage power supply to charge the low-voltage storage battery.

[0042] Specifically, as shown in Figure 2 , the above risk management system is used to manage and control the risk of the vehicle low-voltage system: first, based on the vehicle electronic and electrical architecture, the use scenarios under each power supply mode are sorted out, and the state threshold under each power supply mode is preset in the power supply control module, as shown in Figure 3 , the power supply modes include five key gears: ON gear, ACC gear, OFF gear, sleep gear and deep sleep gear.

[0043] Because each power supply mode is different, the use of high-voltage batteries and low-voltage batteries is different, such as using high-voltage battery power on the ON gear, not using low-voltage battery power, and even charging the low-voltage battery. When using low-voltage battery power supply mode, the situation is also different, therefore, the corresponding state threshold and control measure starting rule are set for each power supply mode, which more comprehensively controls each power consumption link and improves the safety and economy of power consumption.

[0044] Because the risk of power loss is prone to occur in the OFF gear, sleep gear or deep sleep gear, if the current is greater than the corresponding state threshold and the duration exceeds the first preset time in the OFF gear, sleep gear or deep sleep gear, the low-voltage battery is disconnected, and the high-voltage battery is controlled to charge the low-voltage battery.

[0045] In addition, in order to ensure that the low-voltage battery has sufficient power when used in the ACC gear, if the voltage or SOH value is lower than the corresponding state threshold and the duration exceeds the first preset time in the OFF gear, sleep gear or deep sleep gear, the high-voltage battery is controlled to charge the low-voltage battery.

[0046] When the SOC value is lower than the SOC state threshold, high-power constant current charging is performed; when the SOC value is higher than the SOC state threshold, low-power constant voltage charging is performed.

[0047] Because the risk of thermal runaway is more prone to occur in the ON gear or ACC gear, if the current exceeds the corresponding state threshold and the temperature continues to rise for more than a preset time in the ON gear or ACC gear, the low-voltage battery is actively disconnected.

[0048] In addition, the maximum voltage threshold, maximum current threshold and maximum temperature threshold for all power supply modes are also set, and when the corresponding state parameter exceeds any one of the maximum voltage threshold, maximum current threshold or maximum temperature threshold, and the duration exceeds the second preset time, the low-voltage battery is disconnected. For example, misoperation of starting with power, wire harness short circuit, and wire harness aging, the low-voltage power supply is actively disconnected to avoid fire.

[0049] Embodiment 1

[0050] A vehicle model is provided, and the current state threshold in deep sleep is preset to be 100mA, and if the current exceeds the first preset time of 3min, the low-voltage battery is actively disconnected. For example, when the vehicle is in deep sleep, there is an abnormal power consumption of an electric device that cannot sleep, resulting in a current greater than 100mA, and when the duration reaches 3min, the battery control module actively disconnects the low-voltage battery and charges the low-voltage battery through the intelligent DC-DC converter, avoiding the vehicle power loss failure.

[0051] Embodiment 2

[0052] A current state threshold of 20A is preset for a vehicle model, and if the current continuously exceeds the preset value of 20A and the temperature continuously rises, the low-voltage storage battery is actively disconnected. For example, when the wiring harness of the vehicle is damaged to cause a short circuit, the current rises and the temperature rises, exceeding the preset range, and the storage battery control module actively disconnects the low-voltage storage battery, avoiding the failure of the wiring harness of the vehicle being burnt or the vehicle being burnt.

[0053] Embodiment 3

[0054] A maximum voltage of 15V is preset for a vehicle model in the power supply modes of ON / ACC / OFF / hibernation / deep hibernation, and if the voltage exceeds the preset range for a second preset time of 1s, the low-voltage storage battery is actively disconnected. For example, when a user or a maintenance personnel uses a low-voltage lead-acid battery to charge (for example, uses a backup power supply to start the vehicle), a high-voltage power supply is mistakenly connected, causing the voltage of the power supply to be greater than 15V, and the storage battery control module actively disconnects the low-voltage power supply, avoiding the use of the electrical appliance being burnt.

[0055] The technical solutions described above are only specific embodiments of the present application, and for those skilled in the art, on the basis of the principles disclosed in the present application, various types of improvements or modifications can be easily made, and are not limited to the technical solutions described in the above embodiments of the present application. Therefore, the above description is only preferred, and is not limited in nature.

Claims

1. A risk management method for a vehicle low-pressure system, characterized in that: Different state thresholds are set for different power modes; the state parameters of the low-voltage storage battery are collected in real time, and if the current state parameter exceeds the state threshold under the current power mode, a risk warning is performed; The maximum voltage threshold, the maximum current threshold, and the maximum temperature threshold that are common to all power modes are set, and when the corresponding state parameter exceeds any one of the maximum voltage threshold, the maximum current threshold, or the maximum temperature threshold, and the duration exceeds the second preset time length, the low-voltage storage battery is disconnected.

2. The risk management method of a vehicle low-pressure system according to claim 1, characterized in that: The state parameters include current, voltage, temperature, SOC value, and SOH value.

3. The method of claim 1, wherein: When the state parameter exceeds the state threshold and the duration exceeds the preset time length, the control measures are executed.

4. The method of claim 1, wherein: The power modes include five key gears: ON gear, ACC gear, OFF gear, sleep gear, and deep sleep gear.

5. The risk management method of a vehicle low-pressure system according to claim 4, characterized in that: Under the OFF gear, the sleep gear, or the deep sleep gear, if the current continuously exceeds the corresponding state threshold and the duration exceeds the first preset time length, the low-voltage storage battery is disconnected, and the high-voltage battery is controlled to charge the low-voltage storage battery.

6. The method of claim 4, wherein: Under the OFF gear, the sleep gear, or the deep sleep gear, if the voltage or the SOH value is lower than the corresponding state threshold and the duration exceeds the first preset time length, the high-voltage battery is controlled to charge the low-voltage storage battery.

7. The risk management method of a vehicle low-pressure system according to claim 5 or 6, characterized in that: When the SOC value is lower than the SOC state threshold, high-power constant-current charging is performed; when the SOC value is higher than the SOC state threshold, low-power constant-voltage charging is performed.

8. The method of claim 4, wherein: Under the ON gear or the ACC gear, if the current exceeds the corresponding state threshold and the temperature continuously rises for more than the second preset time length, the low-voltage storage battery is actively disconnected.

9. A risk management system for a vehicle low pressure system, the system comprising: The battery state acquisition module, the vehicle control unit, and the power control module are included. The battery state acquisition module is used to collect the state parameters of the low-voltage storage battery in real time. The vehicle control unit is used to determine the current power mode according to the vehicle signals and send it to the power control module. The power control module includes a condition setting unit, a risk warning unit, and a power on-off control unit. The condition setting unit is used to set different state thresholds for different power modes, control measure activation rules, and set the maximum voltage threshold, the maximum current threshold, and the maximum temperature threshold that are common to all power modes. The risk warning unit is used to determine whether the current state parameter exceeds the state threshold under the current power mode and whether the control measures need to be activated. The power on-off control unit is used to disconnect or connect the low-voltage storage battery; when the corresponding state parameter exceeds any one of the maximum voltage threshold, the maximum current threshold, or the maximum temperature threshold, and the duration exceeds the second preset time length, the low-voltage storage battery is disconnected.

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