Low voltage power supply circuit and control method for battery management system controller

Abstract

The present invention discloses a low-voltage power supply circuit and control method for a battery management system controller, comprising: a battery management system controller, a positive discharge unit and an auxiliary discharge unit; the battery management system controller and the positive discharge unit are connected in series to form a discharge loop, the auxiliary discharge unit is connected in parallel to the battery management system controller and the auxiliary discharge unit is communicatively connected to the battery management system controller; when a momentary interruption occurs in the positive discharge unit, the auxiliary discharge unit detects and identifies and outputs a momentary interruption signal to the battery management system controller, and when a momentary interruption occurs, the auxiliary discharge unit provides emergency power supply for the battery management system controller for a period of time.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a low-voltage power supply circuit and control method for a battery management system controller. Background Art

[0002] With the popularity of hybrid vehicles, the control of vehicle power batteries has become a difficult point in research during road tests. The high-voltage battery system is an important and indispensable component of new energy vehicles. The high-voltage battery system requires a battery management system controller to manage its status in vehicle driving or parking scenarios to ensure the safe and reliable operation of the battery system. Therefore, the effective operation of the battery management system controller is crucial, especially the response time of the battery management system manager.

[0003] The main negative contactor adhesion failure rate of vehicles currently in operation on the market is about 8%. When a vehicle has a contactor adhesion failure of varying degrees, it will cause the vehicle to limit its power output, mainly manifested as: the main negative contactor cannot be disconnected and the vehicle has insufficient power. By analyzing the causes of the contactor adhesion failure, it was determined that the high-voltage emergency stop switch, the low-voltage connector of the battery management system controller, and the battery replacement connector and other electronic components were momentarily disconnected and reconnected due to vibration or wading during the vehicle's driving.

[0004] The time between the momentary disconnection and connection of electronic components is short, which will cause the battery management system controller to be unable to recognize the occurrence of the momentary disconnection phenomenon, and unable to send an abnormal power-off request to the hybrid system vehicle controller (Hybrid Control Unit, referred to as HCU). The vehicle controller fails to send power-off control instructions and actions to other components in time. When the momentary disconnection is restored, the high-voltage contactor of the battery system generates a large impact current due to the load operation of controllers such as the HCU, which causes the high-voltage contactor to stick. That is, the battery management system controllers on the existing market cannot recognize the momentary disconnection of electronic components, and when the electronic components are momentarily disconnected, the battery management system controller has no compensation function of its own. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, an embodiment of the present application provides a low-voltage power supply circuit and a control method for a battery management system controller.

[0006] An embodiment of the present invention provides a low-voltage power supply circuit for a battery management system controller, the circuit comprising: a battery management system controller, a positive discharge unit and an auxiliary discharge unit; the battery management system controller is connected in series with the positive discharge unit to form a discharge loop, the auxiliary discharge unit is connected in parallel with the battery management system controller and the auxiliary discharge unit is in communication connection with the battery management system controller;

[0007] When a momentary interruption occurs in the positive discharge unit, the auxiliary discharge unit detects and identifies the momentary interruption and outputs a momentary interruption signal to the battery management system controller. When a momentary interruption occurs, the auxiliary discharge unit provides emergency power supply to the battery management system controller for a period of time.

[0008] According to the low-voltage power supply circuit of the battery management system controller provided in an embodiment of the present invention, the positive discharge unit includes: a low-voltage connector, a power-changing connector, a power supply and a high-voltage emergency stop switch; the low-voltage connector, the power-changing connector, the power supply and the high-voltage emergency stop switch are connected in series with each other and in series with the battery management system controller to form a loop.

[0009] According to the low-voltage power supply circuit of the battery management system controller provided by the embodiment of the present invention, the power supply is a 24-volt battery.

[0010] According to the low-voltage power supply circuit of the battery management system controller provided by the embodiment of the present invention, the auxiliary discharge unit includes a compensation power supply and a bidirectional DC / DC controller; the compensation power supply and the bidirectional DC / DC controller are connected in parallel.

[0011] According to the low-voltage power supply circuit of the battery management system controller provided by the embodiment of the present invention, the compensation power supply includes a capacitor unit composed of a plurality of capacitors connected in parallel.

[0012] According to the low-voltage power supply circuit of the battery management system controller provided by the embodiment of the present invention, the bidirectional DC / DC controller is communicatively connected with the battery management system controller.

[0013] According to the low-voltage power supply circuit of the battery management system controller provided by the embodiment of the present invention, the output port of the bidirectional DC / DC controller detects the terminal voltage of the auxiliary discharge unit, and the input port of the bidirectional DC / DC controller detects the terminal voltage of the power supply.

[0014] According to the low-voltage power supply circuit for a battery management system controller provided by an embodiment of the present invention, the auxiliary discharge unit provides emergency power supply to the battery management system controller for no more than 5 seconds.

[0015] An embodiment of the present invention further provides a control method for a low-voltage power supply circuit of a battery management system controller based on the above embodiment, the control method comprising:

[0016] The bidirectional DC / DC controller in the auxiliary discharge unit detects in real time whether a momentary interruption occurs in each component in the low-voltage power supply circuit of the battery management system controller according to a preset method;

[0017] If no component momentary disconnection occurs, the bidirectional DC / DC controller outputs a signal A to the battery management system controller;

[0018] If a component is disconnected momentarily, the auxiliary discharge unit starts to work, and the bidirectional DC / DC controller outputs a signal B to the battery management system controller;

[0019] If a component is disconnected momentarily, the bidirectional DC / DC controller fails or the compensation power supply voltage is too low, the bidirectional DC / DC controller outputs a signal C to the battery management system controller;

[0020] The battery management system controller performs corresponding judgment processing according to the output signal received from the bidirectional DC / DC controller.

[0021] According to the control method of the low-voltage power supply circuit of the battery management system controller provided by the embodiment of the present invention, the preset method in the bidirectional DC / DC controller includes:

[0022] The bidirectional DC / DC controller performs statistical analysis on the input port voltage and the output port voltage in the circuit;

[0023] When the voltage difference between the input port voltage and the output port voltage of the bidirectional DC / DC controller is between 0 and 2 volts, it is determined that no component instantaneous disconnection occurs in the circuit;

[0024] When the voltage difference between the input port voltage and the output port voltage of the bidirectional DC / DC controller exceeds 2V and the change rate exceeds 500V / s, it is determined that a component momentary disconnection occurs in the circuit.

[0025] The beneficial effects of the present invention are as follows: a low-voltage power supply circuit of a battery management system controller provided by an embodiment of the present invention detects whether a momentary interruption occurs in the entire power supply circuit by adding an auxiliary discharge unit. When a momentary interruption occurs in an electronic component in the circuit, the auxiliary discharge unit outputs a signal to the battery management system controller and supplies power to the battery management system controller for a short time, so that the battery management system controller can make accurate diagnosis and processing when a momentary interruption occurs. The low-voltage power supply capacity of the battery management system controller is optimized by the auxiliary discharge unit, and the circuit structure is simple, easy to implement, and has a low production cost, and also greatly reduces the adhesion failure rate of the main negative contactor of the vehicle high-voltage system. A control method for a low-voltage power supply circuit of a battery management system controller provided by an embodiment of the present invention monitors each component in the low-voltage power supply circuit of the battery management system controller in real time through a bidirectional DC / DC controller in the auxiliary discharge unit, and judges various states in the circuit according to a preset method and outputs corresponding signals, thereby improving the response speed of the circuit and the accuracy of the data, and allowing the battery management system controller to respond in time when a momentary interruption occurs in the circuit, thereby improving the safety of driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0027] Figure 1 This is a schematic diagram of the current electric vehicle discharge circuit structure.

[0028] Figure 2 This is a schematic diagram of the structure of a low-voltage power supply circuit of a battery management system controller provided in an embodiment of the present invention.

[0029] The components in the figure are numbered as follows: battery management system controller 1, low-voltage connector 2, battery replacement connector 3, power supply 4, high-voltage emergency stop switch 5, auxiliary discharge unit 6, compensation power supply 61 and bidirectional DC / DC controller 62. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0031] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0032] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0033] The occurrence rate of adhesion failure of the main negative contactor of the high-voltage system of electric vehicles currently on the market is about 8%. When the vehicle has different degrees of contactor adhesion failure, it will cause the vehicle to limit power output, mainly manifested in the main negative contactor failure to disconnect and the vehicle has insufficient power, affecting the safety of driving the vehicle. Figure 1 As shown in the figure, it is a schematic diagram of the current electric vehicle discharge circuit structure. Figure 1The battery management system controller 1 includes: a battery management system controller 1, a low-voltage connector 2, a power-swap connector 3, a power supply 4, and a high-voltage emergency stop switch 5. The battery management system controller 1, the low-voltage connector 2, the power-swap connector 3, the power supply 4, and the high-voltage emergency stop switch 5 are connected in series to form a discharge circuit. Among them, the battery management system controller 1 is mainly for intelligent management and maintenance of each battery unit, to prevent overcharging and over-discharging of the battery, to extend the service life of the battery, and to monitor the status of the battery. Therefore, the battery management system controller 1 needs to know the working status of each component in time to output various control signals in time. By analyzing the causes of the contactor adhesion failure, it is found that the electronic components such as the high-voltage emergency stop switch 5, the low-voltage plug-in 2 of the battery management system controller 1, and the power-swap connector 3 are caused to be disconnected and reconnected due to vibration or wading during the driving of the vehicle. The time between the two actions of the electronic components from the instantaneous disconnection to the connection is short, and the battery management system controller 1 cannot recognize the occurrence of the instantaneous disconnection, so it cannot send an abnormal power-off request to the hybrid system vehicle controller (Hybrid Control Unit, referred to as HCU), and the vehicle controller cannot send power-off control instructions and actions to other components in time. Since it is a momentary interruption, when the discharge circuit is reconnected, the current in the discharge circuit will be extremely large, and this extremely large current may cause the contactor contacts to stick together. In severe cases, fire or explosion may occur, leading to safety accidents. Moreover, when the momentary interruption is restored, due to the load operation of the controller such as the vehicle controller, the high-voltage contactor of the battery system generates a large impact current, thereby causing the high-voltage contactor to stick together. Generally, the time for the momentary interruption to occur is short, and in very rare cases, it occurs for a longer time. When a momentary interruption occurs and the contactor contacts are closed again, the current in the discharge circuit may not be very large, and it may not necessarily cause the contactor contacts to stick together. However, the probability of momentary interruptions occurring in daily use of electric vehicles is relatively high, and multiple momentary interruptions will greatly increase the probability of contactor contacts sticking together. Therefore, it is very easy to affect the driving safety of the vehicle. For the battery management system controller 1, it is necessary to be able to receive the signal of the momentary interruption in the circuit in a timely manner and handle the momentary interruption phenomenon in a timely manner.

[0034] In view of the above problems, an embodiment of the present invention provides a low-voltage power supply circuit for a battery management system controller, such as Figure 2The figure shows a schematic diagram of the structure of the low-voltage power supply circuit of the battery management system controller provided by an embodiment of the present invention. The circuit includes: a battery management system controller 1, a positive discharge unit and an auxiliary discharge unit 6; the battery management system controller 1 is connected in series with the positive discharge unit to form a discharge circuit, the auxiliary discharge unit 6 is connected in parallel with the battery management system controller 1 and the auxiliary discharge unit 6 is connected in communication with the battery management system controller 1; when a momentary interruption occurs in the positive discharge unit, the auxiliary discharge unit 6 detects and identifies and outputs a momentary interruption signal to the battery management system controller 1, and when a momentary interruption occurs, the auxiliary discharge unit 6 provides emergency power supply to the battery management system controller 1 for a period of time.

[0035] Specifically, the low-voltage power supply circuit of the battery management system controller provided in the embodiment of the present invention optimizes the low-voltage power supply function of the battery management system controller 1 by adding an auxiliary discharge unit 6. The auxiliary discharge unit 6 can monitor the status (voltage information) of each component in the circuit in real time, and transmit the information in the circuit to the battery management system controller 1. The battery management system controller 1 can identify the electronic components in the circuit that have been disconnected by the information transmitted by the auxiliary discharge unit 6. Moreover, when an electronic component in the circuit is disconnected, the battery management system controller 1 can perform voltage compensation through the auxiliary discharge unit 6, and make accurate diagnosis and processing of the disconnection phenomenon. The newly added auxiliary discharge unit 6 not only helps the battery management system controller 1 to identify the electronic components in the circuit that have been disconnected, but also provides the battery management system controller 1 with a voltage compensation function when the electronic components are disconnected.

[0036] In one embodiment, the positive discharge unit includes: a low-voltage connector 2, a power exchange connector 3, a power supply 4 and a high-voltage emergency stop switch 5; the low-voltage connector 2, the power exchange connector 3, the power supply 4 and the high-voltage emergency stop switch 5 are connected in series with each other and in series with the battery management system controller 1 to form a loop.

[0037] In this embodiment, the power source 4 is taken as a 24V battery as an example. In other battery management system controller circuits, other suitable power sources may be used depending on the specific situation, and no further explanation will be given here.

[0038] In one embodiment, the auxiliary discharge unit 6 includes a compensation power supply 61 and a bidirectional DC / DC controller 62; the compensation power supply 61 and the bidirectional DC / DC controller 62 are connected in parallel. The compensation power supply 61 includes a capacitor unit composed of a plurality of capacitors connected in parallel. The bidirectional DC / DC controller 62 is communicatively connected to the battery management system controller 1.

[0039] Specifically, in this embodiment, the compensation power supply 61 is illustrated by taking a capacitor unit composed of several capacitors connected in parallel as an example. The compensation power supply 61 can be modified to other suitable compensation power supplies 61 according to actual conditions, and no further details will be given here. In this embodiment, the compensation power supply 61 is formed by connecting several groups of capacitors in parallel, and connected in parallel with the bidirectional DC / DC controller 62 to form the auxiliary discharge unit 6. The bidirectional DC / DC controller 62 can send a communication signal to the battery management system controller 1 to transmit in real time whether there is a momentary disconnection of electronic components in the circuit. And several groups of capacitors urgently supply power to the battery management system controller 1 when a momentary disconnection occurs in the circuit. In this embodiment, the auxiliary discharge unit 6 provides emergency power supply to the battery management system controller 1 for no more than 5 seconds.

[0040] In this embodiment, the output (P-out) port of the bidirectional DC / DC controller 62 detects the terminal voltage of the auxiliary discharge unit 6, and the input (P-in) port of the bidirectional DC / DC controller 62 detects the terminal voltage of the power supply 4. Specifically, a second-order filter is present in the bidirectional DC / DC controller 62 in the auxiliary discharge unit 6, which can filter out high-frequency signals, and statistically analyze the output (P-out) port terminal voltage and the input (P-in) port terminal voltage in the circuit, and use the real-time least square method to track and process the voltage collected by the bidirectional DC / DC controller 62 in real time, and remove abnormal data during the collection process. The data of the bidirectional DC / DC controller 62 is processed with 80% of the empirical data 1 second before the data is collected and 20% of the collected data as the final result.

[0041] When the bidirectional DC / DC controller 62 detects that the voltage difference between the output (P-out) port voltage and the input (P-in) port voltage in the circuit is between 0-2V, the bidirectional DC / DC controller 62 determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have not been interrupted at this time. At this time, the bidirectional DC / DC controller 62 sends a signal A to the battery management system controller 1. Several groups of capacitors in the auxiliary discharge unit 6 are always connected in parallel with the power supply 4 in the circuit, and several groups of capacitors replenish themselves through the power supply. When the battery management system controller 1 receives the signal A sent by the bidirectional DC / DC controller 62, it determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have not been interrupted at this time, and the battery management system controller 1 is also operating normally.

[0042] When the bidirectional DC / DC controller 62 detects that the voltage difference between the output (P-out) port voltage and the input (P-in) port voltage in the circuit exceeds 2V and the voltage difference change rate reaches 500V / s, the bidirectional DC / DC controller 62 determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have been momentarily disconnected. At this time, the compensation power supply 61 in the auxiliary discharge unit 6 starts to work, and the bidirectional DC / DC controller 62 sends a signal B to the battery management system controller 1. The auxiliary discharge unit 6 switches the port of the bidirectional DC / DC controller 62, and the compensation power supply 61 is connected in parallel with the battery management system controller 1. The compensation power supply 61 supplies power to the battery management system controller 1, and the compensation power supply 61 can only supply power to the battery management system controller 1 for no more than 5 seconds. When the battery management system controller 1 receives the signal B sent by the bidirectional DC / DC controller 62, it determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have been momentarily disconnected. If the duration of the momentary interruption is greater than 3 seconds, the battery management system controller 1 determines that the electronic components in the low-voltage power supply circuit of the battery management system controller are normally disconnected at this time, and the battery management system controller 1 sends a power-off request to the vehicle controller (HCU), and the vehicle controller notifies the battery management system controller 1 to normally disconnect the high voltage. Therefore, it is possible to avoid the risk of adhesion failure of the vehicle contactor or other components due to the large impact current caused by the momentary interruption of the electronic components in the low-voltage power supply circuit of the battery management system controller. If the duration of the momentary interruption is greater than 3 seconds, the battery management system controller 1 fails to send a power-off request to the vehicle controller (HCU) due to its own failure (such as communication failure), and then when the power consumption of the compensation power supply 61 is lower than the power supply range of the battery management system controller 1, the power supply circuit of the battery management system controller 1 is automatically cut off to protect the safety of the circuit.

[0043] When the bidirectional DC / DC controller 62 fails or the compensation power supply 61 is seriously depleted, and the voltage of the compensation power supply 61 is lower than 18V and is about to enter sleep mode, the battery management system controller 1 receives a signal C sent by the bidirectional DC / DC controller 62, indicating that the bidirectional DC / DC controller 62 fails or the compensation power supply 61 is seriously depleted.

[0044] The embodiment of the present invention provides a low-voltage power supply circuit for a battery management system controller. By adding an auxiliary discharge unit 6, the entire power supply circuit is detected to see if a momentary interruption occurs. When a momentary interruption occurs in an electronic component in the circuit, the auxiliary discharge unit 6 outputs a signal to the battery management system controller 1 and supplies power to the battery management system controller 1 for a short time, so that the battery management system controller 1 can make accurate diagnosis and processing when a momentary interruption occurs. The auxiliary discharge unit 6 optimizes the low-voltage power supply capability of the battery management system controller 1, and the circuit structure is simple, easy to implement, and has a low production cost. It also greatly reduces the occurrence rate of adhesion failures of the main negative contactor of the vehicle's high-voltage system.

[0045] An embodiment of the present invention further provides a control method for a low-voltage power supply circuit of a battery management system controller, which is applied to the low-voltage power supply circuit of the battery management system controller in the above embodiment. The control method includes:

[0046] The bidirectional DC / DC controller 62 in the auxiliary discharge unit 6 detects in real time whether a momentary interruption occurs in each component in the low-voltage power supply circuit of the battery management system controller according to a preset method;

[0047] If no component momentary disconnection occurs, the bidirectional DC / DC controller 62 outputs a signal A to the battery management system controller 1;

[0048] If a component is disconnected momentarily, the auxiliary discharge unit 6 starts to work, and the bidirectional DC / DC controller 62 outputs a signal B to the battery management system controller 1;

[0049] If a component is disconnected momentarily, the bidirectional DC / DC controller 62 fails or the voltage of the compensation power supply 61 is too low, the bidirectional DC / DC controller 62 outputs a signal C to the battery management system controller 1;

[0050] The battery management system controller performs corresponding judgment processing according to the output signal of the bidirectional DC / DC controller 62 received.

[0051] In one embodiment, the preset method in the bidirectional DC / DC controller 62 includes:

[0052] The bidirectional DC / DC controller 62 performs statistical analysis on the input port voltage and the output port voltage in the circuit;

[0053] When the voltage difference between the input port voltage and the output port voltage of the bidirectional DC / DC controller 62 is between 0 and 2 volts, it is determined that no component momentary disconnection occurs in the circuit;

[0054] When the voltage difference between the input port voltage and the output port voltage of the bidirectional DC / DC controller 62 exceeds 2V and the change rate exceeds 500V / s, it is determined that a component momentary disconnection occurs in the circuit.

[0055] Specifically, the bidirectional DC / DC controller 62 in the auxiliary discharge unit 6 has a second-order filter, which can filter out high-frequency signals, and perform statistical analysis on the output (P-out) port voltage and the input (P-in) port voltage in the circuit, and use the real-time least square method to track and process the voltage collected by the bidirectional DC / DC controller 62 in real time, and remove abnormal data during the collection process. The data of the bidirectional DC / DC controller 62 is processed with 80% of the empirical data 1 second before the data is collected and 20% of the collected data as the final result.

[0056] When the bidirectional DC / DC controller 62 detects that the voltage difference between the output (P-out) port voltage and the input (P-in) port voltage in the circuit is between 0-2V, the bidirectional DC / DC controller 62 determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have not been interrupted at this time. At this time, the bidirectional DC / DC controller 62 sends a signal A to the battery management system controller 1. Several groups of capacitors in the auxiliary discharge unit 6 are always connected in parallel with the power supply in the circuit, and several groups of capacitors replenish themselves through the power supply. When the battery management system controller 1 receives the signal A sent by the bidirectional DC / DC controller 62, it determines that the electronic components in the low-voltage power supply circuit of the battery management system controller 1 have not been interrupted at this time, and the battery management system controller is also operating normally.

[0057] When the bidirectional DC / DC controller 62 detects that the voltage difference between the output (P-out) port voltage and the input (P-in) port voltage in the circuit exceeds 2V and the voltage difference change rate reaches 500V / s, the bidirectional DC / DC controller 62 determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have been momentarily disconnected. At this time, the compensation power supply 61 in the auxiliary discharge unit 6 starts to work, and the bidirectional DC / DC controller 62 sends a signal B to the battery management system controller 1. The auxiliary discharge unit 6 switches the port of the bidirectional DC / DC controller 62, and the compensation power supply 61 is connected in parallel with the battery management system controller 1. The compensation power supply 61 supplies power to the battery management system controller 1, and the compensation power supply 61 can only supply power to the battery management system controller 1 for no more than 5 seconds. When the battery management system controller 1 receives the signal B sent by the bidirectional DC / DC controller 62, it determines that the electronic components in the low-voltage power supply circuit of the battery management system controller have been momentarily disconnected. If the duration of the momentary interruption is greater than 3 seconds, the battery management system controller 1 determines that the electronic components in the low-voltage power supply circuit of the battery management system controller are normally disconnected at this time, and the battery management system controller 1 sends a power-off request to the vehicle controller (HCU), and the vehicle controller notifies the battery management system controller 1 to normally disconnect the high voltage. Therefore, it is possible to avoid the risk of adhesion failure of the vehicle contactor or other components due to the large impact current caused by the momentary interruption of the electronic components in the low-voltage power supply circuit of the battery management system controller. If the duration of the momentary interruption is greater than 3 seconds, the battery management system controller 1 fails to send a power-off request to the vehicle controller (HCU) due to its own failure (such as communication failure), and then when the power consumption of the compensation power supply 61 is lower than the power supply range of the battery management system controller 1, the power supply circuit of the battery management system controller 1 is automatically cut off to protect the safety of the circuit.

[0058] When the bidirectional DC / DC controller 62 fails or the compensation power supply 61 is seriously depleted, and the voltage of the compensation power supply 61 is lower than 18V and is about to enter sleep mode, the battery management system controller 1 receives a signal C sent by the bidirectional DC / DC controller 62, indicating that the bidirectional DC / DC controller 62 fails or the compensation power supply 61 is seriously depleted.

[0059] A control method for a low-voltage power supply circuit of a battery management system controller provided in an embodiment of the present invention monitors each component in the low-voltage power supply circuit of the battery management system controller in real time through a bidirectional DC / DC controller 62 in an auxiliary discharge unit 6, and judges various states in the circuit according to a preset method and outputs corresponding signals, thereby improving the response speed of the circuit and the accuracy of the data, and allowing the battery management system controller to respond in time when a momentary interruption occurs in the circuit, thereby improving driving safety.

[0060] To sum up, the low-voltage power supply circuit of the battery management system controller provided by the present invention will not cause additional power loss of the power battery. Even if a momentary interruption occurs, no abnormally large current will be generated in the discharge circuit, the contacts of the contactor will not stick, and it is even less likely to cause fire or explosion, leading to safety accidents, thereby greatly improving the safety of electric vehicles.

[0061] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention. Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0062] The above is a detailed introduction to a low-voltage power supply circuit and control method of a battery management system controller provided in an embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and core idea of ​​the present application; ordinary technicians in this field should understand that: they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A low voltage power supply circuit for a battery management system controller, It is characterized in that The circuit comprises: a battery management system controller, a positive discharge unit and an auxiliary discharge unit; the battery management system controller and the positive discharge unit are connected in series to form a discharge loop, the auxiliary discharge unit is connected in parallel with the battery management system controller and the auxiliary discharge unit is communicatively connected with the battery management system controller; the auxiliary discharge unit comprises a compensation power supply and a bidirectional DC / DC controller; the compensation power supply and the bidirectional DC / DC controller are connected in parallel; the bidirectional DC / DC controller is communicatively connected with the battery management system controller; the output port of the bidirectional DC / DC controller detects the terminal voltage of the auxiliary discharge unit, and the input port of the bidirectional DC / DC controller detects the terminal voltage of the power supply; When a momentary interruption occurs in the positive discharge unit, the auxiliary discharge unit detects and identifies the momentary interruption and outputs a momentary interruption signal to the battery management system controller. When a momentary interruption occurs, the auxiliary discharge unit provides emergency power supply to the battery management system controller for a period of time.

2. The low voltage power supply circuit of the battery management system controller according to claim 1, It is characterized in that The positive discharge unit includes: a low-voltage connector, a power-changing connector, a power supply and a high-voltage emergency stop switch; the low-voltage connector, the power-changing connector, the power supply and the high-voltage emergency stop switch are connected in series with each other and in series with the battery management system controller to form a loop.

3. The low voltage power supply circuit of the battery management system controller according to claim 2, It is characterized in that The power source is a 24 volt battery.

4. The low voltage power supply circuit of the battery management system controller according to claim 1, It is characterized in that The compensation power supply includes a capacitor unit composed of a plurality of capacitors connected in parallel.

5. The low voltage power supply circuit of the battery management system controller according to claim 1, It is characterized in that The auxiliary discharge unit provides emergency power to the battery management system controller for no more than 5 seconds.

6. A control method for a low-voltage power supply circuit of a battery management system controller based on any one of claims 1 to 5, It is characterized in that The control method comprises: The bidirectional DC / DC controller in the auxiliary discharge unit detects in real time whether a momentary interruption occurs in each component in the low-voltage power supply circuit of the battery management system controller according to a preset method; If no component momentary disconnection occurs, the bidirectional DC / DC controller outputs a signal A to the battery management system controller; If a component is disconnected momentarily, the auxiliary discharge unit starts to work, and the bidirectional DC / DC controller outputs a signal B to the battery management system controller; If a component is disconnected momentarily, the bidirectional DC / DC controller fails or the compensation power supply voltage is too low, the bidirectional DC / DC controller outputs a signal C to the battery management system controller; The battery management system controller performs corresponding judgment processing according to the output signal received from the bidirectional DC / DC controller.

7. The control method of the low voltage power supply circuit of the battery management system controller according to claim 6, It is characterized in that The preset method in the bidirectional DC / DC controller includes: The bidirectional DC / DC controller performs statistical analysis on the input port voltage and the output port voltage in the circuit; When the voltage difference between the input port voltage and the output port voltage of the bidirectional DC / DC controller is between 0 and 2 volts, it is determined that no component instantaneous disconnection occurs in the circuit; When the voltage difference between the input port voltage and the output port voltage of the bidirectional DC / DC controller exceeds 2V and the change rate exceeds 500V / s, it is determined that a component momentary disconnection occurs in the circuit.

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