Quick-driving battery management system and control method thereof

Abstract

The invention belongs to the technical field of battery management systems, and discloses a fast-driving battery management system, which comprises a main control module, an analog front end module and a fast driving circuit, and is characterized in that the fast driving circuit comprises an energy storage element, a driving switch, a conduction unit, a turn-off unit and a charge-discharge MOS (Metal Oxide Semiconductor) tube. When the charge-discharge MOS tube is controlled to be conducted, the master control module controls the analog front-end module to charge the energy storage element and controls the drive switch to control the conduction unit to enable the energy storage element to charge a junction capacitor of the charge-discharge MOS tube, and rapid conduction of the charge-discharge MOS tube is achieved. When the charge and discharge MOS tube is controlled to be turned off, the main control module controls the drive switch to control the turn-off unit to enable the grid electrode and the source electrode of the charge and discharge MOS tube to be communicated, the junction capacitor is discharged, and rapid turn-off of the charge and discharge MOS tube is achieved. Through the arrangement of the analog front-end module and the rapid driving circuit, rapid switching of the charge-discharge MOS tube is realized, and the problem of weak direct driving capability of the BMS chip is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery management systems, and in particular relates to a fast-driven battery management system and a control method thereof. Background Art

[0002] With the rapid development of new energy markets and technologies, the application of energy storage batteries has become more and more extensive. In large-scale energy storage systems, the battery system needs to support larger charge and discharge currents, and multiple MOSFETs are required to control the input and output of the battery system in parallel to meet the high current requirements. However, as the number of parallel MOSFETs increases, their junction capacitance also increases, requiring higher drive currents to achieve fast switching of MOSFETs to ensure their normal operation under high current conditions.

[0003] However, in the existing technology, the common BMS (battery management system) standard chip directly connects and controls multiple MOSFETs, and the chip output driving capability is limited, making it difficult to provide sufficient driving current. When driving multiple MOSFETs, the switching speed will slow down, causing the MOSFET to be damaged during the switching process, which in turn poses a potential risk to the safety of the battery system. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the battery management system has insufficient driving capability for charging and discharging MOSFETs, resulting in a slow switching speed of the MOSFETs or even damage thereof, thereby providing a fast-driving battery management system and a control method thereof.

[0005] A fast-driven battery management system includes a main control module, an analog front-end module and a fast-driven circuit; The fast driving circuit includes a charging switch module and a discharging switch module; The charging switch module includes a first energy storage element, a first switch, a first conduction unit, a first turn-off unit and a charging MOS tube; the first switch is used to drive the switches of the first conduction unit and the first turn-off unit; the first conduction unit connects the first energy storage element and the gate of the charging MOS tube; the first turn-off unit connects the gate and source of the charging MOS tube; The discharge switch module includes a second energy storage element, a second switch, a second conduction unit, a second turn-off unit and a discharge MOS tube; the second switch is used to drive the switch of the second conduction unit and the second turn-off unit; the second conduction unit connects the second energy storage element and the gate of the discharge MOS tube; the second turn-off unit (connects the gate and source of the discharge MOS tube; The charging switch and the discharging switch are connected in series at the output end of the battery; The analog front-end module is used to collect data of the battery, and includes a first charging port and a second charging port, which are respectively connected to the first energy storage element and the second energy storage element; The main control module is communicatively connected with the analog front-end module, and includes a charging control port and a discharging control port, which are respectively connected to the control ends of the first switch and the second switch.

[0006] Furthermore, the first energy storage element and the second energy storage element are energy storage capacitors.

[0007] Furthermore, the first switch and the second switch include small signal N-channel field effect transistors.

[0008] Furthermore, the first conduction unit and the second conduction unit include small signal P-channel field effect transistors.

[0009] Furthermore, the charging MOS tube and the discharging MOS tube are N-channel field effect tubes.

[0010] Further, the first shut-off unit includes a first control switch tube and a first drive switch tube; the control end of the first control switch tube is connected to the output end of the first drive switch tube, the output end of the first control switch tube is connected to the control end of the first drive switch tube, and the output end of the first drive switch tube is connected to the gate and source of the discharge MOS tube; The second shutdown unit includes a second control switch tube and a second drive switch tube, the control end of the second control switch tube is connected to the output end of the second drive switch tube, the output end of the second control switch tube is connected to the control end of the second drive switch tube, and the output end of the second drive switch tube is connected to the gate and source of the charging MOS tube.

[0011] Furthermore, the first control switch tube and the second control switch tube are small signal N-channel depletion-type field effect tubes; the first drive switch tube and the second drive switch tube are small signal PNP transistors.

[0012] A control method for a fast-driven battery management system, the battery management system being as described above, the method comprising: When driving the charging MOS tube to be turned on, the main control module controls the first charging port of the analog front-end module to start charging, starts timing the charging time of the first energy storage element, and when the charging time reaches a preset time, controls the first charging port of the analog front-end module to stop charging, and controls the first switch to drive the first conduction unit to be turned on; When driving the discharge MOS tube to turn on, the main control module controls the second charging port of the analog front-end module to start charging, starts timing the charging time of the second energy storage element, and when the charging time reaches a preset time, controls the second charging port of the analog front-end module to stop charging, and controls the second switch to drive the second conduction unit to turn on.

[0013] Furthermore, the first energy storage element and the second energy storage element are energy storage capacitors, and the preset time satisfies: t>3RC; Wherein, t is the preset time, R is the corresponding output impedance of the analog front-end module, and C is the capacitance value of the energy storage capacitor.

[0014] Furthermore, the first energy storage element and the second energy storage element are energy storage capacitors. In the charging switch module and the discharging switch module, the capacitance value C of the energy storage capacitor satisfies: C>10*Cj*(Vgs+Vbat) / Vgs; Wherein, Vbat is the maximum operating voltage of the battery; In the charging switch module, Cj is the junction capacitance of the charging MOS tube, and Vgs is the driving voltage of the charging MOS tube; In the discharge switch module, Cj is the junction capacitance of the discharge MOS tube, and Vgs is the driving voltage of the discharge MOS tube.

[0015] Beneficial effects: The present invention discloses a fast-driven battery management system, including a main control module, an analog front-end module and a fast driving circuit, wherein the fast driving circuit includes an energy storage element, a driving switch, a conduction unit, a shutoff unit and a charging and discharging MOS tube. When controlling the charging and discharging MOS tube to be turned on, the main control module controls the analog front-end module to realize the charging of the energy storage element, and controls the driving switch to control the conduction unit so that the energy storage element charges the junction capacitance of the charging and discharging MOS tube, thereby realizing the fast conduction of the charging and discharging MOS tube; when controlling the charging and discharging MOS tube to be turned off, the main control module controls the driving switch to control the shutoff unit so that the gate and source of the charging and discharging MOS tube are connected, so that the junction capacitance is discharged, thereby realizing the fast shutoff of the charging and discharging MOS tube. The present invention realizes the fast switching of the charging and discharging MOS tube through the setting of the analog front-end module and the fast driving circuit, thereby solving the problem of weak direct driving capability of the BMS chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is the circuit principle diagram of the present invention; Figure 2 It is a schematic diagram of the connection structure between the main control module and the analog front-end module of the present invention.

[0018] Explanation of the accompanying drawings: B1, battery; U1, main control module; U2, analog front-end module; C1, first energy storage element; C2, second energy storage element; Q10, charging MOS tube; Q11, first switch; Q12, first conduction unit; Q13, first control switch tube; Q14, first drive switch tube; Q20, discharge MOS tube; Q21, second switch; Q22, second conduction unit; Q23, second control switch tube; Q24, second drive switch tube; R11, first input resistor; R12, first voltage-dividing resistor; R13, second voltage-dividing resistor; R21, second input resistor; R22, third voltage-dividing resistor; R23, fourth voltage-dividing resistor; CRL1, charging control port; CRL2, discharge control port; CHG1, first charging port; CHG2, second charging port; OUT+, positive output terminal; OUT-, negative output terminal. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0020] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0021] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] Embodiment 1: Reference Figure 1 and Figure 2 As shown, this embodiment provides a fast-driven battery management system, including a main control module U1, an analog front-end module U2 and a fast-driven circuit; the fast-driven circuit includes a charging switch module and a discharging switch module; The charging switch module includes a first energy storage element C1, a first switch Q11, a first conduction unit Q12, a first turn-off unit and a charging MOS tube Q10; the first switch Q11 is used to drive the switch of the first conduction unit Q12 and the first turn-off unit; the first conduction unit Q12 connects the first energy storage element C1 and the gate of the charging MOS tube Q10; the first turn-off unit connects the gate and source of the charging MOS tube Q10; the discharging switch module includes a second energy storage element C2, a second switch Q21, a second conduction unit Q22, a second turn-off unit and a discharging MOS tube Q20; the second switch Q21 is used to drive the second conduction unit Q22 and the second turn-off unit The second conduction unit Q22 connects the second energy storage element C2 and the gate of the discharge MOS tube Q20; the second turn-off unit connects the gate and source of the discharge MOS tube Q20; the charging switch and the discharging switch are connected in series at the output end of the battery B1; the analog front-end module U2 is used to collect data of the battery B1, including a first charging port CHG1 and a second charging port CHG2, which are respectively connected to the first energy storage element C1 and the second energy storage element C2; the main control module U1 is connected in communication with the analog front-end module U2, including a charging control port CRL1 and a discharging control port CRL2, which are respectively connected to the control ends of the first switch Q11 and the second switch Q21. The other end of the discharging switch forms the positive output end OUT+ of the battery module, and the negative electrode of the battery B1 forms the negative output end OUT- of the battery module.

[0023] In some implementations of this embodiment, there are multiple charging MOS and discharging MOS, the gate, source and drain of the charging MOS are respectively connected together, and the gate, source and drain of the discharging MOS are respectively connected together, so as to meet the higher charging or discharging current of the battery B1.

[0024] In this embodiment, the first energy storage element C1 and the second energy storage element C2 are energy storage capacitors. Energy storage capacitors have low cost and small leakage current, and are more suitable for the design requirements of low power consumption of BMS.

[0025] As a preferred embodiment of the present invention, the first switch Q11 and the second switch Q21 include small signal N-channel field effect transistors. The first conduction unit Q12 and the second conduction unit Q22 include small signal P-channel field effect transistors. The charging MOS tube Q10 and the discharging MOS tube Q20 are N-channel field effect transistors. Small signal field effect transistors have the characteristics of small junction capacitance, small driving signal current, and fast switching speed. Through a weak voltage signal, it is possible to control the fast switching of the small signal field effect tube, thereby realizing the fast switching of the charging and discharging MOS tube Q20.

[0026] In this embodiment, the first shutoff unit includes a first control switch tube Q13 and a first drive switch tube Q14; the control end of the first control switch tube Q13 is connected to the output end of the first drive switch tube Q14, the output end of the first control switch tube Q13 is connected to the control end of the first drive switch tube Q14, and the output end of the first drive switch tube Q14 is connected to the gate and source of the discharge MOS tube Q20; when the charging control port CRL1 outputs a shutdown control signal, the first switch Q11 quickly shuts off the first conduction unit Q12, cuts off the power supply circuit of the energy storage element to the charging MOS tube Q10, and at the same time, controls the first control switch tube Q13 to turn on, thereby realizing the conduction of the first drive switch tube Q14, so that the gate and drain of the charging MOS tube Q10 are short-circuited, the junction capacitance of the charging MOS tube Q10 is quickly discharged, and the charging MOS tube Q10 is quickly shut down.

[0027] The second shutdown unit includes a second control switch tube Q23 and a second drive switch tube Q24, the control end of the second control switch tube Q23 is connected to the output end of the second drive switch tube Q24, the output end of the second control switch tube Q23 is connected to the control end of the second drive switch tube Q24, and the output end of the second drive switch tube Q24 is connected to the gate and source of the charging MOS tube Q10.

[0028] As a preferred embodiment of the present invention, the first control switch tube Q13 and the second control switch tube Q23 are small signal N-channel depletion type field effect tubes; the first drive switch tube Q14 and the second drive switch tube Q24 are small signal PNP transistors. Small signal N-channel depletion type field effect tubes and small signal PNP transistors have the characteristics of small junction capacitance and fast switching speed. Small signal N-channel depletion type field effect tubes only need a weak voltage signal to achieve conduction, and small signal PNP transistors can achieve several times of current conduction control through tiny current control.

[0029] Specifically, it also includes a first input resistor R11, a first voltage-dividing resistor R12, a second voltage-dividing resistor R13, a second input resistor R21, a third voltage-dividing resistor R22, and a fourth voltage-dividing resistor R23; the first input resistor R11 is connected to the first charging port CHG1 of the analog front-end module U2; the first end of the first voltage-dividing resistor R12 is connected to the source of the charging MOS tube Q10, and the second end is connected to the base of the first control switch tube Q13; the first end of the second voltage-dividing resistor R13 is connected to the base of the first control switch tube Q13, and the second end is connected to the drain of the first switch Q11; the second input resistor R21 is connected to the second charging port CHG2 of the analog front-end module U2; the first end of the third voltage-dividing resistor R22 is connected to the source of the discharging MOS tube Q20, and the second end is connected to the base of the second control switch tube Q23; the first end of the fourth voltage-dividing resistor R23 is connected to the base of the second control switch tube Q23, and the second end is connected to the drain of the second switch Q21.

[0030] Embodiment 2: This embodiment provides a control method for a fast-driven battery management system. The battery management system is as described above, and the method includes: When driving the charging MOS tube Q10 to be turned on, the main control module U1 controls the first charging port CHG1 of the analog front-end module U2 to start charging, starts timing the charging time of the first energy storage element C1, and when the charging time reaches the preset time, controls the first charging port CHG1 of the analog front-end module U2 to stop charging, and controls the first switch Q11 to drive the first conduction unit Q12 to be turned on; When driving the discharge MOS tube Q20 to turn on, the main control module U1 controls the second charging port CHG2 of the analog front-end module U2 to start charging, and starts timing the charging time of the second energy storage element C2. When the charging time reaches the preset time, the second charging port CHG2 of the analog front-end module U2 is controlled to stop charging, and the second switch Q21 is controlled to drive the second conduction unit Q22 to turn on.

[0031] Furthermore, the first energy storage element C1 and the second energy storage element C2 are energy storage capacitors, and the preset time satisfies: t>3RC; Wherein, t is the preset time, R is the corresponding output impedance of the analog front-end module U2, and C is the capacitance value of the energy storage capacitor.

[0032] Furthermore, the first energy storage element C1 and the second energy storage element C2 are energy storage capacitors. In the charging switch module and the discharging switch module, the capacitance value C of the energy storage capacitor satisfies: C>10*Cj*(Vgs+Vbat) / Vgs; Wherein, Vbat is the maximum operating voltage of battery B1; In the charging switch module, Cj is the junction capacitance of the charging MOS tube Q10, and Vgs is the driving voltage of the charging MOS tube Q10; In the discharge switch module, Cj is the junction capacitance of the discharge MOS tube Q20, and Vgs is the driving voltage of the discharge MOS tube Q20.

[0033] The present embodiment provides a fast-driven battery management system, including a main control module, an analog front-end module and a fast driving circuit, wherein the fast driving circuit includes an energy storage element, a driving switch, a conduction unit, a shutoff unit and a charging and discharging MOS tube. When controlling the charging and discharging MOS tube to be turned on, the main control module controls the analog front-end module to realize the charging of the energy storage element, and controls the driving switch to control the conduction unit so that the energy storage element charges the junction capacitance of the charging and discharging MOS tube, thereby realizing the fast conduction of the charging and discharging MOS tube; when controlling the charging and discharging MOS tube to be turned off, the main control module controls the driving switch to control the shutoff unit so that the gate and source of the charging and discharging MOS tube are connected, so that the junction capacitance is discharged, thereby realizing the fast shutoff of the charging and discharging MOS tube. The present invention realizes the fast switching of the charging and discharging MOS tube by setting the analog front-end module and the fast driving circuit, thereby solving the problem of weak direct driving capability of the BMS chip.

[0034] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0035] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A fast-driven battery management system, characterized in that: It includes a main control module, an analog front-end module and a fast driving circuit; The fast driving circuit includes a charging switch module and a discharging switch module; The charging switch module includes a first energy storage element, a first switch, a first conduction unit, a first turn-off unit and a charging MOS tube; the first switch is used to drive the switches of the first conduction unit and the first turn-off unit; The first conduction unit connects the first energy storage element and the gate of the charging MOS tube; the first turn-off unit connects the gate and source of the charging MOS tube; The discharge switch module includes a second energy storage element, a second switch, a second conduction unit, a second turn-off unit and a discharge MOS tube; the second switch is used to drive the switch of the second conduction unit and the second turn-off unit; The second conduction unit connects the second energy storage element and the gate of the discharge MOS tube; The second shut-off unit is connected to the gate and source of the discharge MOS tube; The charging switch and the discharging switch are connected in series at the output end of the battery; The analog front-end module is used to collect data of the battery, and includes a first charging port and a second charging port, which are respectively connected to the first energy storage element and the second energy storage element; The main control module is communicatively connected with the analog front-end module, and includes a charging control port and a discharging control port, which are respectively connected to the control ends of the first switch and the second switch.

2. A fast-driven battery management system according to claim 1, characterized in that: The first energy storage element and the second energy storage element are energy storage capacitors.

3. A fast-driven battery management system according to claim 1, characterized in that: The first switch and the second switch include small signal N-channel field effect transistors.

4. A fast-driven battery management system according to claim 1, characterized in that: The first conduction unit and the second conduction unit include small signal P-channel field effect transistors.

5. A fast-driven battery management system according to claim 1, characterized in that: The charging MOS tube and the discharging MOS tube are N-channel field effect tubes.

6. A fast-driven battery management system according to claim 1, characterized in that: The first shutoff unit includes a first control switch tube and a first drive switch tube; the control end of the first control switch tube is connected to the output end of the first drive switch tube, the output end of the first control switch tube is connected to the control end of the first drive switch tube, and the output end of the first drive switch tube is connected to the gate and source of the discharge MOS tube; The second shutdown unit includes a second control switch tube and a second drive switch tube, the control end of the second control switch tube is connected to the output end of the second drive switch tube, the output end of the second control switch tube is connected to the control end of the second drive switch tube, and the output end of the second drive switch tube is connected to the gate and source of the charging MOS tube.

7. A fast-driven battery management system according to claim 6, characterized in that: The first control switch tube and the second control switch tube are small signal N-channel depletion-type field effect tubes; the first drive switch tube and the second drive switch tube are small signal PNP triodes.

8. A control method for a fast-driven battery management system, characterized in that: The battery management system as claimed in any one of claims 1 to 7, the method comprising: When driving the charging MOS tube to be turned on, the main control module controls the first charging port of the analog front-end module to start charging, starts timing the charging time of the first energy storage element, and when the charging time reaches a preset time, controls the first charging port of the analog front-end module to stop charging, and controls the first switch to drive the first conduction unit to be turned on; When driving the discharge MOS tube to turn on, the main control module controls the second charging port of the analog front-end module to start charging, starts timing the charging time of the second energy storage element, and when the charging time reaches a preset time, controls the second charging port of the analog front-end module to stop charging, and controls the second switch to drive the second conduction unit to turn on.

9. The control method of a fast-driven battery management system according to claim 8, characterized in that: The first energy storage element and the second energy storage element are energy storage capacitors, and the preset time satisfies: t>3RC; Wherein, t is the preset time, R is the corresponding output impedance of the analog front-end module, and C is the capacitance value of the energy storage capacitor.

10. The control method of a fast-driven battery management system according to claim 8, characterized in that: The first energy storage element and the second energy storage element are energy storage capacitors. In the charging switch module and the discharging switch module, the capacitance value C of the energy storage capacitor satisfies: C>10*Cj*(Vgs+Vbat) / Vgs; Wherein, Vbat is the maximum operating voltage of the battery; In the charging switch module, Cj is the junction capacitance of the charging MOS tube, and Vgs is the driving voltage of the charging MOS tube; In the discharge switch module, Cj is the junction capacitance of the discharge MOS tube, and Vgs is the driving voltage of the discharge MOS tube.

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