CN206099459U - A activation circuit for battery management system - Google Patents

Abstract

The utility model discloses an activation circuit for a battery management system, comprising a power supply, an input terminal P+, an output terminal P-, and a system power supply BAT_S, which is connected to a motor M between P+ and P-; The resistor R4, the control terminal of the switching element Q1, and the output terminal of Q1 are connected in series in sequence; BAT_S is connected to the input terminal of the switching element Q3, and the output terminal of Q3 is connected to P+; the control terminal of Q3 is connected to the negative pole of the power supply and R4. The connection nodes are sequentially connected in series with resistor R1, the fourth port of optocoupler U1, the third port of U1 and resistor R3; the first port of U1 is connected to the input terminal P+, and the second port of U1 is connected to Q1 through resistor R2 There is a diode D1 connected in parallel between the output terminal of Q3 and the control terminal, and a capacitor C1 is connected in parallel at both ends of D1; the connection node between the negative pole of the power supply and R4 is grounded. It can be charged and activated in the system placed at the same end, with low self-consumption, wide application and low cost.

Description

An activation circuit for a battery management system

technical field

The utility model relates to the field of battery management systems, in particular to an activation circuit for the battery management system.

Background technique

At present, the global energy and environmental problems are serious, and the development and utilization of new energy are getting more and more attention. As a supplement to traditional energy, new energy can effectively reduce environmental pollution. As an environmentally friendly new energy source, lithium batteries have been widely used in our lives, such as electric vehicles, mobile phones, aerospace, and home energy storage. Therefore, lithium batteries are becoming more and more important in our lives, and because lithium batteries have strong energy characteristics, in consideration of safe use, a good battery management system is required.

At present, there are many lithium battery management systems on the market, but the commonly used output method is to use the same terminal for charging and discharging. In order to better manage and control the lithium battery pack, the lithium battery management system is required to have low power consumption after hibernation to protect the lithium battery and avoid high power consumption of the system when the voltage is low, and discharge the lithium battery to an unrecoverable voltage. At the same time, because the charging and discharging system lines are the same, it needs to be considered in the design. When the system is always loaded, it will consume power through the charging activation control terminal. Therefore, the multi-cell lithium battery management system circulating on the market mostly uses front-end analog ICs (AFE) To detect the load, first activate the front-end AFE, and activate the MCU through the output voltage of the LDO inside the AFE to realize the system operation. Although the activation of charge and discharge is realized, the circuit is complicated and the cost is high.

Utility model content

In view of this, the technical problem to be solved by the utility model is to provide an activation circuit for a battery management system, which can realize charging and discharging activation, low self-consumption after sleep, simple circuit and wide application.

In order to solve the above technical problems, the technical solution provided by the utility model is: an activation circuit for a battery management system, the activation circuit includes a power supply, an input terminal P+ connected to the positive pole of the power supply and used to connect to the charger, and the power supply connected to the negative pole of the charger and used to connect the output terminal P- of the charger and the system power supply BAT_S used to supply power to the battery management system, and a motor M is connected between the input terminal P+ and the output terminal P-; A resistor R4, a control terminal of the switching element Q1, and an output terminal of the switching element Q1 are serially connected in series between the negative pole of the negative electrode and the output terminal P-; the system power supply BAT_S is connected to the input terminal of a switching element Q3, and the switching element Q3 The output terminal is connected to the input terminal P+; the control terminal of the switching element Q3 and the connection node between the negative pole of the power supply and the resistor R4 are sequentially connected in series with a resistor R1, the fourth port of the optocoupler U1, the optocoupler The third port of U1 and the resistor R3; the first port of the optocoupler U1 is connected to the input terminal P+, and the second port of the optocoupler U1 is connected to the input terminal of the switch element Q1 through the resistor R2; the switch element Q3 A diode D1 is connected in parallel between the output terminal and the control terminal, and a capacitor C1 is connected in parallel at both ends of the diode D1; the connection node between the negative pole of the power supply and the resistor R4 is grounded.

Preferably, the optical coupler U1 includes a light emitting diode and a phototransistor.

Preferably, the diode D1 is a Zener diode.

Preferably, the switching element Q1 is a triode.

Preferably, a diode is connected in parallel between the input terminal and the output terminal of the switching element Q3.

Preferably, the switching element Q3 is an enhancement MOS transistor.

Compared with the prior art, the utility model has the following advantages:

1. Compared with the traditional technology, the circuit of the utility model is simple, and the characteristics of discrete components are used to realize the charging activation in the system of charging and discharging at the same terminal;

2. The self-consumption of the circuit is small, which improves the service life of the lithium battery;

3. It can be widely used in lithium battery charging and discharging circuit;

4. Greatly reduce the cost of raw materials.

Description of drawings

FIG. 1 is a schematic structural diagram of an activation circuit used in a battery management system of the present invention.

detailed description

In order to facilitate the understanding of those skilled in the art, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1

As shown in Figure 1, an activation circuit for a battery management system, the activation circuit includes a power supply, connected to the positive pole of the power supply and used to connect to the input terminal P+ of the charger, connected to the negative pole of the power supply and used to connect to the charger The output terminal P- of the battery management system and the system power supply BAT_S for supplying power to the battery management system are connected to a motor M between the input terminal P+ and the output terminal P-; between the negative pole of the power supply and the output terminal P- there are The resistor R4, the control terminal of the switching element Q1, and the output terminal of the switching element Q1.

The system power supply BAT_S is connected to the input terminal of a switching element Q3, and the output terminal of the switching element Q3 is connected to the input terminal P+; the control terminal of the switching element Q3 is sequentially connected in series with the connection node between the negative pole of the power supply and the resistor R4. Resistor R1.

The fourth port of the optocoupler U1, the third port of the optocoupler U1 and the resistor R3; the first port of the optocoupler U1 is connected to the input terminal P+, and the second port of the optocoupler U1 is connected to the switching element Q1 through the resistor R2 A diode D1 is connected in parallel between the output terminal of the switching element Q3 and the control terminal, and a capacitor C1 is connected in parallel at both ends of the diode D1; the connection node between the negative pole of the power supply and the resistor R4 is grounded.

The optocoupler U1 in this embodiment includes a light-emitting diode and a phototransistor; the diode D1 is a Zener diode; the switching element Q1 is a triode; a diode is connected in parallel between the input end and the output end of the switching element Q3; the switching element Q3 is an enhanced MOS tube.

The control end of the switch element Q1 corresponds to the base of the triode, the input end of the switch element Q1 corresponds to the collector of the triode, and the output end of the switch element Q1 corresponds to the emitter of the triode; the transistor is an NPN type transistor.

The control terminal of the switching element Q3 corresponds to the gate of the enhanced MOS transistor, the input end of the switching element Q3 corresponds to the drain of the enhanced MOS transistor, and the output end of the switching element Q3 corresponds to the source of the enhanced MOS transistor; The MOS transistor is a P-channel enhancement type MOS transistor.

The circuit principle in this embodiment is: when charging, when the charger is connected to the input terminal P+ and the output terminal P-, the voltage of the charger decreases after passing through the lithium battery, but when it is still higher than 0.6V, the triode Q1 is turned on , the control terminal connected to the first port and the second port of the optocoupler U1 forms a pressure difference, and the third port and the fourth port are turned on, and the resistor R1 and the resistor R3 form a voltage divider. According to the conduction condition of the MOS tube, GS There is a voltage difference between the poles and reaches the conduction voltage of the MOS tube, the enhanced MOS tube Q3 is turned on, the system power supply BAT_S is short-circuited with the input terminal P+, the voltage is equal, and the system power supply BAT_S can supply power to the system.

When discharging, the moment the load is connected, the voltage of the output terminal P- is equal to the input terminal P+, and the voltage of the output terminal P- is greater than the negative voltage of the power supply, the transistor Q1 is not conducting, and the optocoupler U1 controls the first port and the second port to be unable to conduct. The third port and the fourth port cannot be turned on, the resistor R1 and the resistor R3 do not form a voltage divider, and the voltage of the system power supply BAT_S is equal to 0V. At the same time, because of the characteristics of the transistor Q1, there is no power consumption between the output terminal P- and the negative pole of the power supply. power, thereby putting the system into a low-power mode.

Compared with the traditional technology, the activation circuit for the battery management system of this embodiment is simple, and uses the characteristics of discrete components to realize charging activation in a system with the same terminal for charging and discharging; using the characteristics of the triode Q1, the system is activated when discharging. The power consumption is small, which improves the service life of the lithium battery; and because the components used in the circuit are relatively common, the cost of raw materials is greatly reduced.

The above is the specific implementation of the utility model, and its description is more specific and detailed, but it should not be construed as limiting the patent scope of the utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present utility model, and these obvious replacement forms all belong to the protection scope of the present utility model.

Claims (6)

1. An activation circuit for a battery management system, the activation circuit includes a power supply, an input terminal P+ connected to the positive pole of the power supply and used to connect the charger, and an output terminal P+ connected to the negative pole of the power supply and used to connect the charger - and the system power supply BAT_S for powering the battery management system, characterized in that: the input terminal P+ and the output terminal P- are connected to a motor M; between the negative pole of the power supply and the output terminal P- The resistor R4, the control terminal of the switching element Q1 and the output terminal of the switching element Q1 are connected in series in sequence; the system power supply BAT_S is connected to the input terminal of a switching element Q3, and the output terminal of the switching element Q3 is connected to the input terminal P+; A resistor R1, a fourth port of the optocoupler U1, a third port of the optocoupler U1, and a resistor R3 are sequentially connected in series between the control terminal of the switching element Q3 and the connection node between the negative pole of the power supply and the resistor R4; The first port of the optocoupler U1 is connected to the input terminal P+, and the second port of the optocoupler U1 is connected to the input terminal of the switching element Q1 through a resistor R2; the output terminal of the switching element Q3 and the control terminal are connected in parallel A diode D1, and a capacitor C1 is connected in parallel at both ends of the diode D1; the connection node between the cathode of the power supply and the resistor R4 is grounded. 2. The activation circuit for a battery management system according to claim 1, wherein the optocoupler U1 comprises a light emitting diode and a phototransistor. 3. The activation circuit for a battery management system according to claim 1, wherein the diode D1 is a Zener diode. 4. The activation circuit for a battery management system as claimed in claim 1, wherein the switching element Q1 is a triode. 5. The activation circuit for a battery management system according to claim 1, wherein a diode is connected in parallel between the input terminal and the output terminal of the switching element Q3. 6. The activation circuit for a battery management system according to claim 1 or 5, wherein the switching element Q3 is an enhanced MOS transistor.