CN207098660U - power supply circuit for battery management system - Google Patents

Abstract

The embodiment of the utility model provides a power supply circuit for a battery management system, which belongs to the field of power supply. The power supply circuit includes: a battery power supply module, used to receive power from the battery, the battery power supply module includes a first controllable switch, one end of the first controllable switch is used to connect to the power supply interface of the BMS; a drive module, including a second controllable switch Switch, the closing and opening of the second controllable switch can control the closing and opening of the first controllable switch; and the charger power supply module, used to receive power from the charger and supply power to the BMS, the output terminal of the charger power supply module Connect to one end of the first controllable switch. The power supply circuit can realize the anti-backflow of the charger power supply to the battery, avoiding the power supply part of the charger to start other equipment when the electric vehicle is charged. In addition, the power supply circuit provided by the utility model can reduce the power loss of the power supply circuit during the power supply process.

Description

Power supply circuit for battery management system

technical field

The utility model relates to the field of power supply, in particular to a power supply circuit for a battery management system.

Background technique

Electric vehicles have been vigorously developed due to their advantages of environmental protection and energy saving. Electric vehicles generally use lithium battery packs as the power source. Due to the poor resistance to abuse of lithium batteries, the battery management system (Battery Management System, BMS) is required to detect and manage lithium battery packs during actual use.

In the actual operation of electric vehicles, with the release of the new national charging standard, BMS has three power supply interfaces, including the normal fire power supply, fast charge power supply interface and slow charge power supply interface of the on-board lead-acid battery. Normal fire power supply, while in the charging process, fast charging power supply and slow charging power supply are generally used. Especially for the power supply circuit of the power control part (generally controlling the charge and discharge relay), anti-backflow measures are required, otherwise it may cause other devices powered by the vehicle battery to light up during charging, such as the vehicle controller and motor controller and the like. Conventional anti-backflow is generally realized by using a diode, but the diode consumes a lot of power in the actual working process, which does not meet the requirements of low power consumption.

Utility model content

The purpose of the embodiment of the utility model is to provide a power supply circuit for BMS, which can realize the anti-backflow of the power supply of the charger to the power supply of the vehicle battery, and avoid the power supply part of the charger from the vehicle battery when the electric vehicle is charging. power supply for other equipment.

In order to achieve the above purpose, the embodiment of the utility model provides a power supply circuit for BMS, which is characterized in that the power supply circuit includes:

The battery power supply module is used to receive power from the battery, the battery power supply module includes a first controllable switch, and one end of the first controllable switch is used to connect to the power supply interface of the BMS;

The drive module includes a second controllable switch, the closing and opening of the second controllable switch can control the closing and opening of the first controllable switch; and

The power supply module of the charger is used to receive power from the charger and supply power to the electric equipment. The output end of the power supply module of the charger is connected to one end of the first controllable switch.

Optionally, the first controllable switch may be a metal oxide semiconductor (Metal Oxide Semiconductor, MOS) field effect transistor (MOS transistor).

Optionally, the battery power supply module may further include a third controllable switch, the third controllable switch is a MOS transistor, the gate and source of the first controllable switch are respectively connected to the gate and source of the third controllable switch source connection.

Optionally, the battery power supply module may further include: a first capacitor connected between the drain of the third controllable switch and the ground terminal; and/or a capacitor connected between the source and the gate of the third controllable switch second capacitor.

Optionally, the battery power supply module may further include a first Zener diode connected between the gate and the source of the first controllable switch, and the anode of the first Zener diode is connected to the gate of the first controllable switch. connected, the cathode of the first Zener diode is connected to the source of the first controllable switch.

Optionally, the second controllable switch is a MOS transistor, and the drain of the second controllable switch is connected to the gate of the first controllable switch.

Optionally, the driving module may further include: a first triode, the base of which is used to receive a switch control signal; a second triode, whose base is connected to the first triode The collector of a triode is connected, and the collector of the second triode is connected with the gate of the second controllable switch.

Optionally, the driving module may further include a second Zener diode connected between the source and the gate of the second controllable switch, and the anode of the second Zener diode is connected to the source of the second controllable switch , the cathode of the second Zener diode is connected to the gate of the second controllable switch.

Optionally, the charger power supply module may include a MOS transistor, the drain of the MOS transistor is used to connect to the charger, and the source of the MOS transistor is connected to one end of the first controllable switch.

Optionally, a third Zener diode is connected between the gate and the source of the MOS transistor, the anode of the third Zener diode is connected to the gate of the MOS transistor, and the cathode of the third Zener diode is connected to the gate of the MOS transistor. source connection.

Through the above-mentioned technical solution, the power supply circuit for the battery management system BMS provided by the utility model can prevent the power supply part of the charger from backfilling the vehicle battery part when the electric vehicle is charging, and avoid supplying power to the vehicle battery at this time. Power supply for electrical equipment. In addition, because the anti-backflow of the power supply circuit adopts a circuit design based on MOS transistors, the power loss of the power supply circuit itself can also be reduced, saving energy.

Other features and advantages of the embodiments of the present utility model will be described in detail in the following specific embodiments.

Description of drawings

The accompanying drawings are used to provide a further understanding of the embodiments of the present utility model, and constitute a part of the description, together with the following specific embodiments, are used to explain the embodiments of the present utility model, but do not constitute limitations to the embodiments of the present utility model. In the attached picture:

Fig. 1 is a structural block diagram of a power supply circuit for a BMS according to an embodiment of the present invention;

2 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention;

3 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention;

4 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention;

5 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention; and

Fig. 6 is a structural block diagram of a power supply device for a BMS according to an embodiment of the present invention.

Explanation of reference signs

1. Battery power supply module 2. Drive module

3. Charger power supply module 4. Processor

Q1, the first controllable switch Q2, the second controllable switch

Q3, the third controllable switch Q4, the fourth controllable switch

Q5, the first transistor Q6, the second transistor

C1, the first capacitor C2, the second capacitor

C3, the third capacitor C4, the fourth capacitor

R1, first resistor R2, second resistor

R3, the third resistor R4, the fourth resistor

R5, the fifth resistor R6, the sixth resistor

R7, seventh resistor R8, eighth resistor

R9, the ninth resistor D1, the first Zener diode

D2, second Zener diode D3, third Zener diode

Detailed ways

The specific implementation manners of the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to describe and explain the embodiments of the present utility model, and are not intended to limit the embodiments of the present utility model.

Fig. 1 is a structural block diagram of a power supply circuit for a BMS according to an embodiment of the present invention. As shown in Figure 1, the power supply circuit may include:

The battery power supply module 1 is used to receive power from the battery. The battery power supply module 1 may include a first controllable switch Q1, one end of the first controllable switch Q1 is used to connect to a power supply interface of the BMS. The battery may be an on-board battery.

The driving module 2 may include a second controllable switch Q2. The closing and opening of the second controllable switch Q2 can control the closing and opening of the first controllable switch Q1; and

The charger power supply module 3 is used to receive power from the charger and supply power to the BMS. The output terminal of the charger power supply module 3 can be connected to one end of the first controllable switch Q1 connected to the BMS power supply interface.

Examples of the first controllable switch Q1 and/or the second controllable switch Q2 may include: a triode, a MOS transistor or an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT). Preferably, the first controllable switch Q1 and/or the second controllable switch Q2 may be MOS transistors.

Fig. 2 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention. In an embodiment of the present invention, the battery power supply module 1 may further include a third controllable switch Q3. Examples of the third controllable switch Q3 may include: a triode, a MOS transistor or an IGBT. Preferably, the third controllable switch Q3 may be a MOS transistor. An example of a circuit structure of the battery power supply module 1 is shown in FIG. 2 . As shown in FIG. 2 , the first controllable switch Q1 and the third controllable switch Q3 can be P-channel MOS transistors, but they are not limited thereto. Those skilled in the art can understand that for example, N-channel MOS transistors are also applicable. The gate and source of the first controllable switch Q1 are respectively connected to the gate and source of the third controllable switch Q3, therefore, when the first controllable switch Q1 is turned on, the third controllable switch Q3 is also turned on Conversely, when the third controllable switch Q3 is turned on, the first controllable switch Q1 is also turned on; the turning-off mechanism of the two is similar to the turning-on mechanism, and will not be repeated here. When the second controllable switch Q2 is turned on, the first controllable switch Q1 and the third controllable switch Q3 are also turned on, at this time, the battery power supply module 1 is connected to the power supply interface of the BMS, and the battery supplies power to the BMS through the battery power supply module 1 powered by. When the second controllable switch Q2 is turned off, the first controllable switch Q1 and the third controllable switch Q3 are turned off, and at this time, the battery power supply module 1 is disconnected from the power supply interface of the BMS. Optionally or additionally, the battery power supply module 1 may further include: a first capacitor C1 connected between the drain of the third controllable switch Q3 and the ground terminal and/or a source connected to the third controllable switch Q3 The second capacitor C2 between the electrode and the gate. The first capacitor C1 and the second capacitor C2 can be used to filter the voltage input from the battery. In this embodiment, the battery power supply module 1 may further include a first zener diode D1 connected between the gate and source of the first controllable switch Q1, the anode of the first zener diode D1 is connected to the first The gate of the controllable switch Q1 is connected, and the cathode of the first zener diode D1 is connected to the source of the first controllable switch Q1, which is used to protect the first controllable switch Q1 and the third controllable switch Q3, preventing the first The voltage difference between the gate and the source of the controllable switch Q1 and the third controllable switch Q3 is too large, and the MOS transistor burns out. At the same time, the use of the first zener diode D1 can also reduce the power consumption between the gate and the source of the first controllable switch Q1 and the third controllable switch Q3 . A first resistor R1 may also be connected in series between the source and the gate of the first controllable switch Q1, and the first resistor R1 is used for the gate of the first controllable switch Q1 (and the third controllable switch Q3). A voltage bias is provided between the terminal and the source. In this implementation manner, the resistance of the first resistor R1 may be, for example, 47 kΩ. A ninth resistor R9 may also be connected between the gate of the first controllable switch Q1 and the second controllable switch Q2, and the ninth resistor R9 may be used for voltage division. The resistance of the ninth resistor R9 may be, for example, 10 kΩ.

Although FIG. 2 shows the specific components and circuit structure of the battery power supply module 1, those skilled in the art can understand that what FIG. 2 shows is an example of the battery power supply module 1, so the battery power supply module 1 is not limited to that shown in FIG. specific example given.

Fig. 3 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention. In an embodiment of the present invention, as shown in FIG. 3 , the driving module 2 may further include: a first triode Q5 and a second triode Q6 . The base of the first triode Q5 is used to receive a switch control signal through a control signal interface, for example, receive a switch control signal (such as high level and low level) from a processor (such as a microcontroller), and the first triode Q5 The emitter is grounded. A second resistor R2 is connected in series between the emitter and the base of the first transistor Q5, and the second resistor R2 is used to provide a voltage bias between the base and the emitter of the first transistor Q5, The second resistor R2 can be, for example, 47 kΩ. The base of the first transistor Q5 can also receive a control signal through a third resistor R3, and the resistance of the third resistor R3 can be, for example, 4.7 kilohms. The base of the second transistor Q6 is connected to the collector of the first transistor Q5. A fourth resistor R4 may be connected in series between the base of the second transistor Q6 and the collector of the first transistor Q5, and the resistance of the fourth resistor Q4 may be, for example, 4.7 kΩ. A fifth resistor R5 may be connected in series between the base and the emitter of the second transistor Q6, and the fifth resistor R5 is used to provide a voltage bias between the base and the emitter of the second transistor Q6, The fifth resistor R5 can be selected as a resistor of, for example, 47 kilohms. The emitter of the second transistor Q6 can be connected to a positive voltage (eg +5V).

Although the first transistor Q5 shown in FIG. 3 is an NPN transistor, those skilled in the art can understand that a PNP transistor is also applicable. Likewise, the second transistor Q6 shown in FIG. 3 is a PNP transistor, but those skilled in the art can understand that an NPN transistor is also applicable. In addition, although it is shown in FIG. 3 that the driving module 2 may include two transistors, those skilled in the art may understand that the driving module 2 may include more or less transistors.

As shown in FIG. 3 , the second controllable switch Q2 may be an N-channel MOS transistor, and the collector of the second transistor Q6 is connected to the gate of the second controllable switch Q2 . A sixth resistor R6 may be connected in series between the collector of the second transistor Q6 and the gate of the second controllable switch Q2, and the resistance of the sixth resistor R6 may be, for example, 1 kΩ. In addition, a seventh resistor R7 may be connected in series between the collector of the second transistor Q6 and the source of the second controllable switch Q2, and the resistance of the seventh resistor R7 may be, for example, 20 kΩ. The source of the second controllable switch Q2 can be grounded. The seventh resistor R7 can be used to provide voltage bias for the gate and source of the second controllable switch Q2. In this embodiment, the driving circuit 2 may further include a third capacitor C3 connected between the gate and the source of the second controllable switch Q2 for filtering. In this embodiment, a second zener diode D2 is connected between the gate and source of the second controllable switch Q2, and the anode of the second zener diode D2 is connected to the source of the second controllable switch Q2. connected, the cathode of the second Zener diode D2 is connected to the gate of the second controllable switch Q2, which is used to limit the voltage between the gate and the source of the second controllable switch Q2, and avoid damage to the second controllable switch Q2 , such a design can also reduce the power consumption between the gate and the source of the second controllable switch Q2.

When, for example, the processor 4 (such as a single-chip microcomputer) (such as through a control signal interface) outputs the first switch control signal (such as a high level) to the base of the first transistor Q5, the base of the first transistor Q5 and A bias voltage is generated between the emitters, so the collector and the emitter of the first triode Q5 are turned on, so that the fifth resistor R5 has a current flowing through it, so there is a current between the base and the emitter of the second triode Q6 A bias voltage is generated so that the collector and emitter of the second transistor Q6 are turned on. Thus, the current flows through the seventh resistor R7, so a bias voltage is generated between the gate and source of the second controllable switch Q2, so that the drain and source of the second controllable switch Q2 are turned on, resulting in the first controllable switch Q2 The control switch Q1 is closed. On the contrary, for example, when the processor outputs the second switch control signal (for example, low level) to the base of the first transistor Q5, the second controllable switch Q2 is turned off, causing the first controllable switch Q1 to also be turned off.

Although the specific components and circuit structure of the driving module 2 are shown in FIG. 3, those skilled in the art can understand that what FIG. 3 shows is an example of the driving module 2, so the driving module 2 is not limited to the specific components shown in FIG. example of .

Fig. 4 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention. In an embodiment of the present invention, as shown in FIG. 4 , the charger power supply module 3 may include a fourth controllable switch Q4. Examples of the fourth controllable switch Q4 may include: a triode, a MOS transistor or an IGBT. Preferably, the fourth controllable switch Q4 may be a MOS transistor. More preferably, the fourth controllable switch Q4 can be a P-channel MOS transistor, but those skilled in the art can understand that an N-channel MOS transistor is also applicable. The drain of the fourth controllable switch Q4 can be connected to the positive pole of the charger (such as OBC+12V shown in Figure 4), the gate of the fourth controllable switch Q4 can be grounded, and the fourth controllable switch Q4 The source of can be connected to the power supply interface of the BMS (or the output terminal of the first controllable switch Q1). A fourth capacitor C4 is connected between the drain of the fourth controllable switch Q4 and the ground terminal, and the fourth capacitor C4 is used for filtering the current input from the charger. A third zener diode D3 is connected between the source and the gate of the fourth controllable switch Q4, the anode of the third zener diode D3 is connected to the gate of the fourth controllable switch Q4, the third zener diode The negative electrode of D3 is connected to the source electrode of the fourth controllable switch Q4, which is used to limit the voltage between the source electrode and the gate electrode of the fourth controllable switch Q4, protect the fourth controllable switch Q4, and reduce the fourth Power dissipation between the source and gate of controllable switch Q4. An eighth resistor R8 is also connected between the gate of the fourth controllable switch Q4 and the ground terminal, and the resistance of the eighth resistor R8 may be, for example, 10 kΩ.

Although the specific components and circuit structure of the charger power supply module 3 are shown in FIG. 4, those skilled in the art can understand that what FIG. 4 shows a specific example.

Fig. 5 is a schematic structural diagram of a power supply circuit for a BMS according to an embodiment of the present invention. The embodiment of the power supply circuit shown in FIG. 5 may include an example battery power supply module 1 as shown in FIG. 2 , an example driving module 2 as shown in FIG. 3 , and an example charger power supply module 3 as shown in FIG. 4 .

When the vehicle battery is required to supply power to the BMS, the processor (for example, a single-chip microcomputer) can output a high level to the base of the first triode Q5, and at this time, the conductor between the collector and the emitter of the first triode Q5 The emitter and the collector of the second triode Q6 are turned on, so that the second controllable switch (MOS tube) Q2 is turned on, and then the first controllable switch and the third controllable switch (MOS tube) Q1 and Q3 are turned on, and the on-board battery supplies power to the BMS.

When switching to the charger for power supply, the processor 4 will receive a signal (such as a switching signal), and when receiving the signal, the processor can output, for example, a low level to the base of the first triode Q5, thereby The first triode Q5, the second triode Q6, the second controllable switch Q2, the first and the third controllable switches Q1 and Q3 are disconnected to prevent the charger from supplying power to the equipment powered by the vehicle battery, thereby avoiding The case of backwashing.

In addition, the anti-backflow of the power supply circuit provided by the embodiment of the utility model adopts a circuit design based on a MOS tube, which can reduce the power loss of the power supply circuit itself and save energy.

Fig. 6 is a structural block diagram of a power supply device for a BMS according to an embodiment of the present invention. As shown in FIG. 6, the power supply device for BMS may include the power supply circuit of the above-mentioned embodiment and a processor 4, and the processor 4 may be configured to output a first switch control signal to the drive module when the charger is not working, so as to The first controllable switch Q1 is turned on, and the second switch control signal is output to the driving module when the charger is working, so that the first controllable switch Q1 is turned off.

The optional implementation of the utility model has been described in detail above in conjunction with the accompanying drawings, but the implementation of the utility model is not limited to the specific details of the above-mentioned implementation, and within the scope of the technical concept of the implementation of the utility model, the utility model Various simple modifications are made to the technical solutions of the embodiments, and these simple modifications all belong to the protection scope of the embodiments of the present utility model.

In addition, it should be noted that the various specific technical features described in the above specific implementation manners may be combined in any suitable manner if there is no contradiction. In order to avoid unnecessary repetition, the embodiments of the present utility model will not further describe various possible combinations.

Claims (10)

1. A power supply circuit for a battery management system, wherein the power supply circuit comprises: A battery power supply module (1), configured to receive power from a battery, the battery power supply module (1) comprising a first controllable switch (Q1), one end of the first controllable switch (Q1) being used to connect to the BMS power supply interface; a drive module (2), comprising a second controllable switch (Q2), the closing and opening of the second controllable switch (Q2) can control the closing and opening of the first controllable switch (Q1); and A charger power supply module (3), configured to receive power from the charger and supply power to the battery management system BMS, the output end of the charger power supply module (3) is connected to the first controllable switch (Q1) the one end. 2. The power supply circuit according to claim 1, characterized in that, the first controllable switch (Q1) is a Metal Oxide Semiconductor Field Effect Transistor. 3. The power supply circuit according to claim 2, characterized in that, the battery power supply module (1) further comprises a third controllable switch (Q3), and the third controllable switch (Q3) is a metal oxide semiconductor A field effect transistor, the gate and source of the first controllable switch (Q1) are respectively connected to the gate and source of the third controllable switch (Q3). 4. The power supply circuit according to claim 3, characterized in that, the battery power supply module (1) further comprises: a first capacitor (C1) connected between the drain of said third controllable switch (Q3) and ground; and/or A second capacitor (C2) connected between the source and gate of said third controllable switch (Q3). 5. The power supply circuit according to claim 3, characterized in that, the battery power supply module further comprises a first Zener diode ( D1), the anode of the first zener diode (D1) is connected to the gate of the first controllable switch (Q1), and the cathode of the first zener diode (D1) is connected to the first controllable switch (Q1). Source Connection for Switch (Q1). 6. The power supply circuit according to claim 1, characterized in that, the second controllable switch (Q2) is a metal oxide semiconductor field effect transistor, and the drain of the second controllable switch (Q2) is connected to the Gate connection of the first controllable switch (Q1). 7. The power supply circuit according to claim 6, characterized in that, the drive module (2) further comprises: a first triode (Q5), the base of the first triode (Q5) is used to receive a switch control signal; The second triode (Q6), the base of the second triode (Q6) is connected to the collector of the first triode (Q5), and the collector of the second triode (Q6) The electrodes are connected to the gate of said second controllable switch (Q2). 8. The power supply circuit according to claim 7, characterized in that, the drive module (2) further comprises a second regulator connected between the source and the gate of the second controllable switch (Q2) A diode (D2), the anode of the second zener diode (D2) is connected to the source of the second controllable switch (Q2), and the cathode of the second zener diode (D2) is connected to the second Gate Connection for Controllable Switch (Q2). 9. The power supply circuit according to claim 1, characterized in that, the charger power supply module (3) comprises a metal oxide semiconductor field effect transistor, and the drain of the metal oxide semiconductor field effect transistor is used for charging The source of the metal oxide semiconductor field effect transistor is connected to the one end of the first controllable switch (Q1). 10. The power supply circuit according to claim 9, characterized in that, a third voltage stabilizing diode (D3) is connected between the source and the gate of the metal oxide semiconductor field effect transistor, and the third voltage stabilizing diode (D3) The anode of the diode (D3) is connected to the gate of the metal oxide semiconductor field effect transistor, and the cathode of the third constant voltage diode (D3) is connected to the source of the metal oxide semiconductor field effect transistor.