Battery system with peak voltage suppression function
By using an MCU-controlled discharge and charge module, combined with a peak voltage absorption module, the problem of peak voltage caused by back electromotive force during battery charging is solved, achieving a battery system design that reduces cost and saves space.
Patent Information
- Application Number
- CN202511792522.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-02-17
AI Technical Summary
In existing technologies, when a battery system rapidly shuts off the charging circuit due to a fault during charging, the reverse electromotive force generated by the generator inductance causes voltage spikes, which can damage electrical equipment. Furthermore, existing solutions are costly, occupy a large area, and are difficult to effectively suppress voltage spikes.
The discharge and charge modules controlled by an MCU, combined with a peak voltage absorption module including a control unit, a freewheeling unit, and an energy storage unit, absorb reverse current through a low-impedance path to suppress peak voltage, thus replacing the traditional supercapacitor series scheme.
It effectively suppresses voltage spikes, reduces battery system costs, and minimizes the footprint of printed circuit boards, which is beneficial for the miniaturization and integration of battery products.
Smart Images
Figure CN121546771A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of battery systems, in particular to a battery system with a spike voltage suppression function. BACKGROUND
[0002] In a vehicle such as a truck, the battery system is connected with the generator on the vehicle, and the battery system is charged by the generator. However, the generator is essentially a large inductive load, and according to the inductive characteristic, the current flowing through the inductor cannot be abruptly changed. During the battery charging process, if the system needs to be quickly shut down due to a fault, the charging current will decrease sharply, and at this time the generator inductance will generate a very high reverse electromotive force, forming a transient spike voltage. The value of the transient spike voltage may be far beyond the normal working voltage range of the system, thereby damaging various electrical equipment on the vehicle.
[0003] In order to solve the above problems, a common solution in the prior art is to directly connect a large number of supercapacitors in series at the output end (between P+ and P-) of the battery system. For example, in a 24V system, 11 to 12 3V / 30F supercapacitors are usually connected in series to build an absorption circuit. The circuit absorbs energy by quickly charging the capacitors when a spike voltage occurs, thereby suppressing the voltage rise. However, the cost of connecting multiple supercapacitors in series is very high, increasing the overall manufacturing cost of the battery; secondly, the spike voltage suppression effect of this solution is limited, especially in the case of a very high current change rate, there is still a risk of voltage exceeding the standard; finally, multiple large-volume supercapacitors will occupy a large area on the printed circuit board (PCB), which is not conducive to the miniaturization and integration design of the product. SUMMARY
[0004] In view of the deficiencies of the prior art, a battery system with a spike voltage suppression function is provided.
[0005] To achieve the above object, the application provides a battery system with a spike voltage suppression function, comprising a battery, having a positive electrode and a negative electrode, the positive electrode being connected with a positive electrode output end; an MCU; a discharging module, electrically connected with the MCU and the negative electrode; when the MCU receives a discharging signal, the MCU controls the discharging module to be turned on, and the battery is discharged; a charging module, electrically connected with the MCU, the discharging module and the negative electrode output end; when the MCU receives a charging signal, the MCU controls the charging module to be turned on, and the battery is charged; and a spike voltage absorption module, comprising a control unit, a freewheeling unit and an energy storage unit; the input end of the control unit is connected with the MCU, and the output end thereof is connected with the freewheeling unit; the freewheeling unit is connected with the energy storage unit and the negative electrode output end respectively, and the energy storage unit is also connected with the positive electrode output end; during the charging process of the battery, when the MCU receives a fault signal, the MCU controls the charging module to be turned off and controls the control unit to be turned on, and after the charging module is turned off, a reverse current is generated; after the control unit is turned on, the freewheeling unit is controlled to be turned on, and the reverse current flows into the freewheeling unit and the energy storage unit in turn.
[0006] According to an embodiment of the application, the energy release module further comprises a relay driving unit, a heating relay and a heating film; the input end of the relay driving unit is connected with the MCU, the output end of the relay driving unit is connected with the coil end of the heating relay, one end of the switch end of the heating relay is connected with the positive electrode output end and one end of the energy storage unit, the other end of the heating film is connected with the other end of the energy storage unit and the freewheeling unit respectively.
[0007] According to an embodiment of the application, the discharging module comprises a first gate driving unit and a MOS tube Q4; one end of the first gate driving unit is connected with the MCU, and the other end thereof is connected with the gate of the MOS tube Q4; the source of the MOS tube Q4 is connected with the negative electrode, and the drain of the MOS tube Q4 is connected with the charging module.
[0008] According to an embodiment of the application, the charging module comprises a MOS tube Q5 and a charging control unit; the drain of the MOS tube Q5 is connected with the discharging module, the gate of the MOS tube Q5 is connected with the charging control unit and the control unit, and the source of the MOS tube Q5 is connected with the charging control unit and the negative electrode output end; the input end of the charging control unit is connected with the MCU, and the output end of the charging control unit is connected with the MOS tube Q5 and the negative electrode output end.
[0009] According to one embodiment of the present invention, the control unit includes a comparator U1, a voltage divider assembly, a first current limiting assembly, a pull-up resistor R16, a second current limiting assembly, a MOSFET Q8, and a second gate driving unit. The comparator U1 has a non-inverting input terminal IN+ and an inverting input terminal IN-. One end of the voltage divider assembly is connected to the MCU, and the other end is connected to the non-inverting input terminal IN+. One end of the first current limiting assembly is connected to the inverting input terminal IN-, and the other end is connected to the charging module. One end of the pull-up resistor R16 is connected to the inverting input terminal IN- and the first current limiting assembly, and the other end is connected to the second current limiting assembly and the drain of the MOSFET Q8. The other end of the second current limiting assembly is connected to a second power supply voltage. The gate of the MOSFET Q8 is connected to the MCU, and the source of the MOSFET Q8 is connected to the VSS terminal of the comparator U1. The VCC terminal of the comparator U1 is connected to the first power supply voltage, and the output terminal of the comparator U1 is connected to the second gate driving unit, which is connected to a freewheeling unit.
[0010] According to one embodiment of the present invention, the freewheeling unit includes MOSFET Q7 and MOSFET Q6. The drain of MOSFET Q7 is connected to the energy storage unit, and the gate of MOSFET Q7 is connected to the control unit. The gate of MOSFET Q6 is connected to the control unit, the drain of MOSFET Q6 is connected to the source of MOSFET Q7, and the source of MOSFET Q6 is connected to the charging module and the negative output terminal, respectively.
[0011] According to one embodiment of the present invention, the energy storage unit includes capacitor C1 and capacitor C2. One end of capacitor C1 is connected to the positive output terminal and capacitor C2 respectively, and the other end of capacitor C1 is connected to the freewheeling unit and capacitor C2 respectively.
[0012] According to one embodiment of the present invention, the charging control unit includes a first control component, a second control component, diodes D1 and D2, and a discharging component; the first control component, the second control component, and the discharging component each have a first terminal, a second terminal, and a third terminal; the first terminal of the first control component is connected to the MCU, the second terminal of the first control component is connected to the first terminal of the second control component, and the third terminal of the first control component is grounded; the second terminal of the second control component is connected to a first power supply voltage, and the third terminal of the second control component is connected to the anode of diode D1; the cathode of diode D1 is connected to the anode of diode D2 and the first terminal of the discharging component; the cathode of diode D2 is connected to the second terminal of the control unit, the second terminal of the discharging component, and the gate of MOSFET Q5; the second terminal of the discharging component is connected to the control unit and the gate of MOSFET Q5, and the third terminal of the discharging component is connected to the source and the negative output terminal of MOSFET Q5.
[0013] According to one embodiment of the present invention, the first control component includes a MOSFET Q1, a resistor R1 and a resistor R2, and the second control component includes a transistor Q2, a resistor R3 and a resistor R4; one end of the resistor R1 is connected to the MCU, and the other end is connected to the resistor R2 and the gate of the MOSFET Q1, respectively; the source of the MOSFET Q1 and the other end of the resistor R2 are grounded together; the drain of the MOSFET Q1 is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the resistor R4 and the base of the transistor Q2, respectively; the other end of the resistor R4 and the emitter of the transistor Q2 are connected to the first power supply voltage; and the collector of the transistor Q2 is connected to the positive terminal of the diode D1.
[0014] According to one embodiment of the present invention, the discharge assembly includes a transistor Q3, a resistor R7, and a resistor R6. The base of transistor Q3 is connected to the cathode of diode D1 and the anode of diode D2, respectively. The emitter of transistor Q3 is connected to the control unit and the gate of MOSFET Q5, respectively. The collector of transistor Q3 is connected to one end of resistor R7, and the other end of resistor R7 is connected to the source of MOSFET Q5. One end of resistor R6 is connected to the base of transistor Q3, and the other end of resistor R6 is connected to resistor R7 and the source of MOSFET Q5, respectively.
[0015] The beneficial effects of this invention are as follows: if a fault occurs during charging, MCU2 controls the charging module to shut down. When the charging module is shut down, the generator (large inductor) will generate an extremely high back electromotive force (spiking voltage) due to a sudden current change. Simultaneously, the MCU activates the control unit, which in turn activates the freewheeling unit. The freewheeling unit creates a low-impedance freewheeling path for the high-voltage spike current generated by the generator. The sudden current flows into the energy storage unit after passing through the freewheeling unit, where it absorbs the dangerous energy generated by the sudden change in inductive load current, thereby suppressing the voltage spike. Thus, when a fault occurs in the battery system during charging, shutting down the charging module cuts off the battery's charging path, preventing irreversible damage to the battery and the entire battery system caused by the charging fault. This replaces the traditional method of absorbing spike voltages by connecting multiple supercapacitors in series, effectively reducing the manufacturing cost of the battery system and the footprint of the printed circuit board, which is beneficial for the miniaturization and integration design of battery products. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a circuit diagram of a battery system with peak voltage suppression function in one of the embodiments.
[0017] Reference numerals 1. Battery; 2. MCU; 3. Discharge module; 31. First gate drive unit; 4. Charging module; 41. Charging control unit; 411. First control component; 412. Second control component; 413. Discharge component; 5. Peak voltage absorption module; 51. Control unit; 511. Voltage divider component; 512. First current limiting component; 513. Second current limiting component; 514. Second gate drive unit; 52. Freewheeling unit; 53. Energy storage unit; 6. Energy release module; 61. Relay drive unit; 62. Heating relay; 63. Heating film. Detailed Implementation
[0018] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.
[0019] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this invention.
[0020] Please refer to Figure 1 , Figure 1 Figure 1This is a circuit diagram of a battery system with peak voltage suppression function. This embodiment provides a battery system with peak voltage suppression function, which has a positive output terminal P+ and a negative output terminal P-. The battery system with peak voltage suppression function includes a battery 1, an MCU 2, a discharge module 3, a charging module 4, and a peak voltage absorption module 5. The battery 1 has a positive terminal B+ and a negative terminal B-, and the positive terminal B+ of the battery 1 is connected to the positive output terminal P+. In the connection, the discharge module 3 is connected to the MCU 2, the negative terminal B- of the battery 1, and the charging module 4. The charging module 4 is connected to the MCU 2, the peak voltage absorption module 5, and the negative output terminal P-. The peak voltage absorption module 5 is connected to the MCU 2, the negative output terminal P-, and the positive output terminal P+. The peak voltage absorption module 5 includes a control unit 51, a freewheeling unit 52, and an energy storage unit 53. The input terminal of the control unit 51 is connected to the MCU2, and its output terminal is connected to the freewheeling unit 52. The freewheeling unit 52 is connected to the energy storage unit 53 and the negative output terminal P- respectively. The energy storage unit 53 is also connected to the positive output terminal P+.
[0021] The discharge module 3 is used to control the opening and closing of the unidirectional discharge path of battery 1. When MCU2 receives the discharge signal sent by the host computer, MCU2 controls the discharge module 3 to turn on, and battery 1 discharges. The discharge current of battery 1 is output sequentially to the positive output terminal P+ and the negative output terminal P- through the discharge module 3 to supply power to the load connected to the positive output terminal P+ and the negative output terminal P-.
[0022] The charging module 4 is used to control the on / off state of the charging path of battery 1. When MCU2 receives a charging signal from the host computer, MCU2 controls the charging module 4 to turn on, at which point the charging path of battery 1 is activated, and the generator charges battery 1.
[0023] During the charging process of battery 1, when MCU2 receives a fault signal, MCU2 controls charging module 4 to shut down and controls control unit 51 to turn on. A reverse current is generated when charging module 4 is shut down. After control unit 51 turns on, it controls freewheeling unit 52 to turn on, allowing the reverse current to flow into freewheeling unit 52, providing a freewheeling path for the reverse current generated when charging module 4 is shut down. The reverse current then flows into energy storage unit 53 after passing through freewheeling unit 52. It should be noted that during battery system charging, in case of faults such as excessively high charging voltage, excessive charging current, or abnormal battery temperature, the host computer sends a fault signal to MCU2.
[0024] In practical use, the positive terminal B+ and the negative terminal P- of battery 1 are connected to the generator via power lines, and the load is connected in parallel between the positive terminal P+ and the negative terminal P-. When the battery system discharges to the load, MCU2 controls the discharge module 3 to turn on, while the charging module 4 turns off. This forms a unidirectional discharge path from battery 1 to the load, and turning off the charging module 4 prevents current from flowing back into battery 1. When the generator charges the battery system, MCU2 controls the charging module 4 to turn on and keeps the discharge module 3 on, ensuring that while the battery system is charging, power is continuously supplied to the load, allowing the load to maintain normal operation.
[0025] If a fault occurs during charging, MCU2 controls charging module 4 to shut down. When charging module 4 is shut down, the generator (large inductor) will generate an extremely high back electromotive force (spiking voltage) due to a sudden current change. Simultaneously, MCU2 activates control unit 51, which in turn activates freewheeling unit 52. Freewheeling unit 52 creates a low-impedance freewheeling path for the high-voltage spike current generated by the generator. The sudden current flows into energy storage unit 53 after passing through freewheeling unit 52, absorbing the dangerous energy generated by the sudden change in inductive load current, thereby suppressing the voltage spike. Thus, when a fault occurs in the battery system during charging, shutting down charging module 4 cuts off the charging path of battery 1, preventing irreversible damage to battery 1 and the entire battery system caused by the charging fault. This replaces the traditional solution of absorbing spike voltages by connecting multiple supercapacitors in series, effectively reducing the manufacturing cost of the battery system and the footprint of the printed circuit board, which is beneficial for the miniaturization and integration design of battery products.
[0026] Furthermore, to prepare the energy storage unit 53 for the next energy storage cycle, the peak voltage suppression circuit of the battery system in this example also includes an energy release module 6. The energy release module 6 includes a relay drive unit 61, a heating relay 62, and a heating film 63. In configuration, the input terminal of the relay drive unit 61 is connected to the MCU2, the output terminal of the relay drive unit 61 is connected to the coil terminal of the heating relay 62, one end of the switching terminal of the heating relay 62 is connected to the positive terminal B+ of the battery 1 and one end of the energy storage unit 53, and the other end is connected to the heating film 63. The heating film 63 is also connected to both the energy storage unit 53 and the freewheeling unit 52.
[0027] In this example, MCU2 has I / O1, I / O2, I / O3, I / O4, and I / O5 terminals. The input terminal of relay driver unit 61 is connected to I / O4 of MCU2. When energy storage unit 53 needs to release energy, MCU2's I / O4 terminal sends a high-level signal to relay driver unit 61, causing relay driver unit 61 to turn on. After relay driver unit 61 turns on, the coil terminal of heating relay 62 is energized, causing the switch terminal of heating relay 62 to close. At this time, energy storage unit 53 discharges, and the energy released by energy storage unit 53 powers heating film 63. Heating film 63 converts the energy released by energy storage unit 53 into thermal energy, thereby achieving the effect of energy release. After energy storage unit 53 has completed energy release, MCU2 controls relay driver unit 61 to turn off, completing the energy release and preparing energy storage unit 53 for the next energy storage. In this example, relay driver unit 61 is a relay driver used to control the operation of the relay, which is existing technology.
[0028] Furthermore, the discharge module 3 includes a first gate driving unit 31 and a MOSFET Q4. One end of the first gate driving unit 31 is connected to the MCU2, and the other end is connected to the gate of the MOSFET Q4. The source of the MOSFET Q4 is connected to the negative terminal B- of the battery 1, and the drain of the MOSFET Q4 is connected to the charging module 4. In this example, the first gate driving unit 31 is a gate driver, and its input terminal is connected to the I / O5 terminal of the MCU2. When the I / O5 terminal of the MCU2 sends a high level, the first gate driving unit 31 turns on and drives the MOSFET Q4 to close and conduct; when the I / O5 terminal of the MCU2 sends a low level, the first gate driving unit 31 drives the MOSFET Q4 to turn off.
[0029] In this example, the discharge module 3 also includes resistors R21 and R20. One end of resistor R21 is connected to the negative terminal B- of battery 1 and the source of MOSFET Q4, respectively, and the other end is connected to the first gate drive unit 31 and resistor R20, respectively. The other end of resistor R20 is connected to the gate of MOSFET Q4. Resistors R20 and R21 are used for current shunting.
[0030] The charging module 4 includes a MOSFET Q5 and a charging control unit 41. The drain of the MOSFET Q5 is connected to the discharge module 3, the gate of the MOSFET Q5 is connected to the charging control unit 41 and the control unit 51, and the source of the MOSFET Q5 is connected to the charging control unit 41 and the negative output terminal P-. The input terminal of the charging control unit 41 is connected to the MCU2, and the output terminal of the charging control unit 41 is connected to the MOSFET Q5 and the negative output terminal P-.
[0031] The charging module 4 also includes resistors R8 and R9. One end of resistor R8 is connected to the gate of MOSFET Q5, and the other end is connected to resistor R9, charging control unit 41, and control unit 51, respectively. The other end of resistor R9 is connected to the source and negative output terminal P- of MOSFET Q5, respectively. Resistor R8 is used to limit the current of the electrical signal output by charging control unit 41, and resistors R8 and R9 are used for voltage division.
[0032] In actual use, the input terminal of the charging control unit 41 is connected to the I / O1 terminal of MCU2. When MCU2 controls the charging module 4 to turn on, the I / O1 terminal of MCU2 sends a high-level signal to the input terminal of the charging control unit 41. Upon receiving the high-level signal, the charging control unit 41 conducts, thereby turning on the MOSFET Q5. When MCU2 controls the charging module 4 to turn off, the I / O1 terminal of MCU2 sends a low-level signal to the charging control unit 41. The charging control unit 41 receives the low-level signal and cannot conduct, causing the MOSFET Q5 to turn off.
[0033] Furthermore, the charging control unit 41 includes a first control component 411, a second control component 412, diodes D1 and D2, and a discharging component 413. The first control component 411, the second control component 412, and the discharging component 413 each have a first terminal, a second terminal, and a third terminal. The first terminal of the first control component 411 is connected to the MCU2, the second terminal of the first control component 411 is connected to the first terminal of the second control component 412, and the third terminal of the first control component 411 is grounded. The second terminal of the second control component 412 is connected to a first supply voltage, and the third terminal of the second control component 412 is connected to the anode of diode D1. The cathode of diode D1 is connected to the anode of diode D2 and the first terminal of the discharging component 413. The cathode of diode D2 is connected to the control unit 51, the second terminal of the discharging component 413, and the gate of MOSFET Q5. The second terminal of the discharging component 413 is connected to the control unit 51 and the gate of MOSFET Q5, and the third terminal of the discharging component 413 is connected to the source and the negative output terminal P- of MOSFET Q5.
[0034] When charging module 4 is activated, the I / O1 pin of MCU2 sends a high-level signal to the first terminal of the first control component 411. Upon receiving the high-level signal, the first control component 411 conducts, and subsequently, the second control component 412 conducts. The 12V supply voltage connected to the second terminal of the second control component 412 passes sequentially through the second control component 412, diode D1, and diode D2 before being input to the gate of MOSFET Q5, causing MOSFET Q5 to close and conduct. In this example, diode D1 is used for freewheeling. When the second control component 412 changes from conducting to cutoff, it may generate a reverse electromotive force. Diode D1 provides a path for the reverse current, suppressing voltage spikes and protecting the second control component 412 and subsequent circuitry. Diode D2 is used for reverse isolation to prevent current from flowing back into MCU2.
[0035] When charging module 4 is turned off, the I / O1 pin of MCU2 sends a low-level signal to the first pin of the first control component 411. Upon receiving the low-level signal, the first control component 411 turns off, causing the second control component 412 to turn off, which in turn turns off MOSFET Q5. When MOSFET Q5 is turned off, the gate and source of MOSFET Q5 are rapidly discharged through the discharge component 413, causing MOSFET Q5 to turn off quickly.
[0036] Specifically, the first control component 411 includes a MOSFET Q1, resistors R1 and R2, and the second control component 412 includes a transistor Q2, resistors R3 and R4. One end of resistor R1 serves as the first terminal of the first control component 411 and is connected to the MCU2. The other end of resistor R1 is connected to the gate of resistor R2 and the MOSFET Q1. The source of MOSFET Q1 serves as the third terminal of the first control component 411 and is grounded together with the other end of resistor R2. The drain of MOSFET Q1 serves as the second terminal of the first control component 411 and is connected to one end of resistor R3. The other end of resistor R3 is connected to the base of resistor R4 and the base of transistor Q2. The other end of resistor R4 and the emitter of transistor Q2 serve as the second terminal of the second control component 412 and are connected to the second supply voltage. The collector of transistor Q2 serves as the third terminal of the second control component 412 and is connected to the anode of diode D1.
[0037] In this example, one end of resistor R1 is connected to the I / O1 terminal of MCU2. Resistor R1 is used for current limiting, and resistor R2 is used for voltage division and biasing. Resistor R3 is used for current limiting and also provides a bias voltage to the base of transistor Q2. Resistor R4 is used for current limiting. When charging module 4 is turned on, the I / O1 terminal of MCU2 outputs a high-level signal. This high-level signal is current-limited by resistor R1 and input to the gate of MOSFET Q1 after being divided by resistors R1 and R2, causing MOSFET Q1 to close and conduct. After MOSFET Q1 closes, the base potential of transistor Q2 is pulled low by the drain of MOSFET Q1, making the base voltage of transistor Q2 lower than its emitter voltage, at which point transistor Q2 conducts. After transistor Q2 conducts, the 12V supply voltage is input to the gate of MOSFET Q5 through diodes D1 and D2 in sequence, causing MOSFET Q5 to conduct. In this example, the second control component 412 also includes resistor R5, which is used for current limiting. After transistor Q2 is turned on, the 12V power supply voltage is limited by resistor R5 and then input to diode D1.
[0038] When charging module 4 is closed, the I / O1 pin of MCU2 sends a low-level signal, causing MOSFET Q1 to turn off. After MOSFET Q1 turns off, transistor Q2 turns off, thus turning off MOSFET Q5. When MOSFET Q5 is off, due to the parasitic capacitance between its base and source, the voltage between the base and source of MOSFET Q5 cannot drop to zero instantaneously. When MOSFET Q5 is turned off, its base and source are rapidly discharged through discharge component 413, causing MOSFET Q5 to turn off quickly.
[0039] Furthermore, the discharge assembly 413 includes a transistor Q3, a resistor R7, and a resistor R6. The base of transistor Q3 serves as the first terminal of the discharge assembly 413 and is connected to the cathode of diode D1 and the anode of diode D2. The emitter of transistor Q3 serves as the second terminal of the discharge assembly 413 and is connected to the control unit 51, the cathode of diode D2, and the gate of MOSFET Q5. The collector of transistor Q3 is connected to one end of resistor R7, and the other end of resistor R7 serves as the third terminal of the discharge assembly 413 and is connected to the source of MOSFET Q5. One end of resistor R6 is connected to the base of transistor Q3, and the other end of resistor R6 is connected to resistor R7 and the source of MOSFET Q5.
[0040] When charging module 4 is turned on, the I / O1 pin of MCU2 outputs a high-level signal, and MOSFETs Q1, Q2, and Q5 are turned on sequentially. Because the source potential of MOSFET Q5 is very low when it is turned on, the base potential of transistor Q3 is also very low, thus failing to reach the turn-on threshold of transistor Q2. Therefore, during the normal conduction period of MOSFET Q5, transistor Q3 is in the off state due to insufficient base drive. When MCU2 receives a fault signal and turns off charging module 4, the I / O1 pin of MCU2 outputs a low-level signal, and MOSFETs Q1, Q2, and Q5 are turned off sequentially. When MOSFET Q5 is turned off, the turn-off action of MOSFET Q5 triggers the reverse electromotive force generated by the generator. This electromotive force sharply raises the source potential of MOSFET Q5. This increased potential provides the base drive current of transistor Q3 through resistor R6, enabling transistor Q3 to meet the conduction condition and turn on instantaneously. This provides a low-impedance fast discharge channel for the gate of MOSFET Q5, ultimately ensuring that MOSFET Q5 can be turned off quickly and reliably.
[0041] The control unit 51 includes a comparator U1, a voltage divider component 511, a first current limiting component 512, a pull-up resistor R16, a second current limiting component 513, a MOSFET Q8, and a second gate drive unit 514. The comparator U1 has a non-inverting input terminal IN+ and an inverting input terminal IN-. One end of the voltage divider component 511 is connected to the MCU2, and the other end is connected to the non-inverting input terminal IN+. One end of the first current limiting component 512 is connected to the inverting input terminal IN-, and the other end is connected to the charging module 4. One end of the pull-up resistor R16 is connected to both the inverting input terminal IN- and the first current limiting component 512, and the other end is connected to both the second current limiting component 513 and the drain of the MOSFET Q8. The other end of the second current limiting component 513 is connected to a second supply voltage, which in this example is +5V. The gate of the MOSFET Q8 is connected to the MCU2, and the source of the MOSFET Q8 is connected to the VSS terminal of the comparator U1. The VCC terminal of comparator U1 is connected to a first supply voltage, which in this example is +12V. The output terminal of comparator U1 is connected to a second gate drive unit 514, which is connected to a freewheeling unit 52.
[0042] Specifically, the I / O3 terminal of MCU2 is connected to one end of the voltage divider component 511, and the I / O2 terminal of MCU2 is connected to the second current limiting component 513. The other end of the second current limiting component 513 is connected to the pull-up resistor R16 and the drain of the MOSFET Q8. One end of the first current limiting component 512 is connected to the charging control unit 41 and the gate of the MOSFET Q5, and the other end is connected to the pull-up resistor R16 and the inverting input terminal IN-.
[0043] When the spike voltage absorption module 5 is activated, the I / O2 and I / O3 terminals of MCU2 output high levels respectively. The high level output from the I / O3 terminal of MCU2 is divided by the voltage divider component 511 and then input to the non-inverting input terminal IN+ of comparator U1. The second supply voltage is input to the inverting input terminal IN- of comparator U1 after passing through the second current limiting component 513 and the pull-down resistor R16. This ensures that the voltage at the inverting input terminal IN- of comparator U1 is higher than the voltage at the non-inverting input terminal IN+ when comparator U1 is powered on, avoiding the problem of comparator U1 erroneous output due to the floating inverting input terminal IN- during power-on. The I / O2 terminal of MCU2 outputs a high level to the gate of MOSFET Q8, causing MOSFET Q8 to conduct. After MOSFET Q8 is turned on, the lower end of the pull-up resistor R16 is shorted to ground. At this time, the second current limiting unit and the pull-down resistor R16 form a voltage divider to ground. At this time, the voltage at the inverting input terminal of comparator U1 is equal to the voltage between the gate and source of MOSFET Q5. When the charging module 4 is turned off, the MOSFET Q5 is turned off. Due to the action of the discharge component 413, the voltage between the gate and source of the MOSFET Q5 drops rapidly. When the voltage between the gate and source of the MOSFET Q5 is lower than the voltage at the inverting input terminal of the comparator U1 (i.e., the voltage divided by resistors R14 and R13), the output terminal of the comparator U1 outputs a high-level signal. After receiving the high-level signal, the second gate driving unit 514 drives the freewheeling unit 52 to turn on.
[0044] When the spike voltage absorption module 5 is turned off, both the I / O3 and I / O2 terminals of MCU2 output low-level signals, causing comparator U1 to output a low-level signal. After receiving the low-level signal, the second gate drive unit 514 outputs a low-level signal to the freewheeling unit 52, causing the freewheeling unit 52 to be turned off.
[0045] In this example, the first voltage divider component 511 includes resistors R13 and R14. One end of resistor R14 is connected to the I / O3 terminal of MCU2, and the other end is connected to the non-inverting input terminal IN+ of comparator U1 and resistor R13, respectively. The other end of resistor R13 is grounded. Resistors R13 and R14 are used to divide the electrical signal at the non-inverting input terminal IN+ of comparator U1. Since comparator U1 outputs a high level to control the freewheeling unit 52 to turn on when the voltage at the inverting input terminal IN- of comparator U1 is less than the voltage at the non-inverting input terminal IN+ after MOSFET Q5 is turned off, the threshold for turning on the freewheeling power supply can be set by changing the resistance values of resistors R13 and R14.
[0046] The first current limiting component 512 includes a diode D6 and a resistor R15. The diode D6 is used to unidirectionally guide the electrical signal to the gate of the MOSFET Q5, and the resistor R15 is used for current limiting. The second current limiting component 513 includes a diode D5 and a resistor R17. The diode D5 is used to unidirectionally guide the second supply voltage, and the resistor R17 is used for current limiting.
[0047] Furthermore, the control unit 51 also includes a pull-up resistor R12. One end of the pull-up resistor R12 is connected to the output of comparator U1 and the second gate driving unit 514, and the other end is connected to the first power supply voltage and the second gate driving unit 514. Since comparator U1 is an open-drain input, a pull-up resistor R12 is added to the output to enable comparator U1 to output a high level. In this example, the second gate driving unit 514 is a gate driver.
[0048] The control unit 51 also includes resistors R18 and R19. One end of resistor R18 is connected to the I / O2 terminal of MCU2, and the other end is connected to the gate of MOSFET Q8 and resistor R19. The other end of resistor R19 is connected to the source of MOSFET Q8 and the VSS terminal of comparator U1. Resistor R18 is used for current limiting, and resistor R19 is used to divide voltage in conjunction with resistor R18.
[0049] The control unit 51 also includes a diode D4, the anode of which is connected to the second gate drive unit 514, and the cathode of which is connected to the freewheeling unit 52. The diode D4 is used to prevent the electrical signal output by the second gate drive unit 514 from flowing in the reverse direction.
[0050] Furthermore, the freewheeling unit 52 includes MOSFET Q7 and MOSFET Q6. The drain of MOSFET Q7 is connected to the energy storage unit 53, and the gate of MOSFET Q7 is connected to the control unit 51. The gate of MOSFET Q6 is connected to the control unit 51, the drain of MOSFET Q6 is connected to the source of MOSFET Q7, and the source of MOSFET Q6 is connected to the negative output terminal P-.
[0051] The freewheeling unit 52 also includes resistors R10 and R11. One end of resistor R10 is connected to the second gate driving unit 514, and the other end is connected to the gate of MOSFET Q7, resistor R11, and the gate of MOSFET Q6, respectively. The other end of resistor R11 is connected to the source of MOSFET Q7 and the drain of MOSFET Q6, respectively. Resistor R10 is used for current limiting, and resistor R11 is a discharge resistor for heating the gates of MOSFETs Q6 and Q7, which discharges residual charge on the gates, protects the gates of the MOSFETs, and ensures reliable turn-off of MOSFETs Q6 and Q7.
[0052] When MOSFET Q5 is turned off and MCU2 is turned on to enable the spike voltage absorption module 5, both I / O3 and I / O2 of MCU2 output high-level signals. When the voltage at the inverting input IN- of comparator U1 is lower than the voltage at the non-inverting input IN+, comparator U1 outputs a high-level signal, causing the second gate drive unit 514 to send a high-level signal to the gates of MOSFETs Q6 and Q7, thus turning on MOSFETs Q6 and Q7. After MOSFETs Q6 and Q7 are turned on, the voltage between the gate and source of MOSFET Q5 passes through MOSFETs Q6 and Q7 sequentially and is input into the energy storage unit 53.
[0053] When the spike voltage absorption module 5 is turned off, both I / O3 and I / O2 of MCU2 output low-level signals, causing comparator U1 to output a low-level signal. The second gate drive unit 514 receives the low-level signal and sends a low-level signal to the gates of MOSFETs Q6 and Q7, causing MOSFETs Q7 and Q6 to turn off.
[0054] The energy storage unit 53 includes capacitor C1 and capacitor C2. One end of capacitor C1 is connected to the positive terminal B+ and capacitor C2 respectively, and the other end is connected to the freewheeling unit 52 and capacitor C2 respectively.
[0055] In this example, capacitors C1 and C2 are both supercapacitors. When the peak voltage absorption module 5 is turned on, capacitors C1 and C2 absorb the electrical signal sent by the freewheeling module. When the energy release module 6 is turned on, capacitors C1 and C2 discharge, and the energy stored in capacitors C1 and C2 is released through the energy release module 6, preparing capacitors C1 and C2 for the next energy storage.
[0056] In summary, when MCU2 receives a discharge signal, its I / O5 pin sends a high-level signal to the first gate drive unit 31, which in turn drives MOSFET Q4 to turn on. Battery 1 discharges to the load. The current from battery 1 is output to the load through its positive terminal B+, then input to the negative terminal through the load, then input to MOSFET Q4 through the diode inside MOSFET Q5, and finally returns to the negative terminal B+ of battery 1, thus forming a complete discharge circuit.
[0057] When MCU2 receives a charging signal, its I / O1 sends a high-level signal, causing MOSFET Q1 and transistor Q2 to conduct in sequence. This results in MOSFET Q5 receiving a high-level signal at its gate and conducting as well. The current output from the generator is input to the positive terminal B+ of battery 1, then flows through the inside of battery 1, and subsequently through MOSFETs Q4 and Q5 before returning to the negative terminal P- of the generator, thus forming a complete charging circuit.
[0058] During battery charging, if MCU2 receives a fault signal, its I / O1, I / O2, and I / O3 terminals will send low-level signals. When the gate of MOSFET Q1 receives a low-level signal, MOSFET Q1 and transistor Q2 will sequentially turn off, causing the gate of MOSFET Q5 to be low, thus turning off MOSFET Q5. Due to the parasitic capacitance between the base and source of MOSFET Q5, the voltage between the base and source of MOSFET Q5 cannot drop to zero instantaneously. When MOSFET Q5 is turned off, the voltage between the base and source of MOSFET Q5 discharges rapidly through resistor R7 and transistor Q3, simultaneously turning on transistor Q3. When the voltage between the base and source of MOSFET Q5 drops to the voltage at the non-inverting input of comparator U1, the output of comparator U1 will output a high-level signal to drive the second gate drive unit 514, causing the second gate drive unit 514 to drive MOSFETs Q7 and Q6 to turn on. After MOSFETs Q6 and Q7 are turned on, a low-impedance freewheeling path is created for the high-voltage peak current generated by the generator. The high-voltage peak current is input into the energy storage unit 53 through MOSFETs Q6 and Q7, where it is absorbed and stored. When the host computer detects that the energy storage unit 53 is fully charged and needs to release energy, it sends a release signal to the MCU2. Upon receiving the release signal, the MCU2 sends a high-level signal at its I / O4 terminal to drive the relay drive unit 61, which in turn drives the heating relay 62 to close. After the heating relay 62 closes, the energy stored in the energy storage unit 53 is released to the heating film 63, where the electrical energy is converted into heat energy and released to prepare for the next energy storage cycle.
[0059] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.
Claims
1. A battery system with peak voltage suppression function, having a positive output terminal and a negative output terminal, characterized in that, include: The battery (1) has a positive electrode and a negative electrode, wherein the positive electrode is connected to the positive electrode output terminal; MCU (2); The discharge module (3) is electrically connected to the MCU (2) and the negative terminal; when the MCU (2) receives the discharge signal, the MCU (2) controls the discharge module (3) to be turned on, and the battery (1) discharges; The charging module (4) is electrically connected to the MCU (2), the discharging module (3), and the negative output terminal; when the MCU (2) receives a charging signal, the MCU (2) controls the charging module (4) to turn on, and the battery (1) is charged; and The peak voltage absorption module (5) includes a control unit (51), a freewheeling unit (52), and an energy storage unit (53); the input terminal of the control unit (51) is connected to the MCU (2), and its output terminal is connected to the freewheeling unit (52); the freewheeling unit (52) is connected to the energy storage unit (53) and the negative output terminal respectively, and the energy storage unit (53) is also connected to the positive output terminal; during the charging process of the battery (1), when the MCU (2) receives a fault signal, the MCU (2) controls the charging module (4) to close and controls the control unit (51) to turn on, and the charging module (4) generates a reverse current after it is closed; after the control unit (51) turns on, it controls the freewheeling unit (52) to turn on, and the reverse current flows into the freewheeling unit (52) and the energy storage unit (53) in sequence.
2. The battery system with peak voltage suppression function according to claim 1, characterized in that, It also includes an energy release module (6), which includes a relay drive unit (61), a heating relay (62), and a heating film (63). The input terminal of the relay drive unit (61) is connected to the MCU (2), and the output terminal of the relay drive unit (61) is connected to the coil terminal of the heating relay (62). One end of the switch terminal of the heating relay (62) is connected to the positive output terminal and one end of the energy storage unit (53), and the other end is connected to the heating film (63). The other end of the heating film (63) is connected to the other end of the energy storage unit (53) and the freewheeling unit (52).
3. The battery system with peak voltage suppression function according to claim 1, characterized in that, The discharge module (3) includes a first gate driving unit (31) and a MOS transistor Q4. One end of the first gate driving unit (31) is connected to the MCU (2), and the other end is connected to the gate of the MOS transistor Q4. The source of the MOS transistor Q4 is connected to the negative terminal, and the drain of the MOS transistor Q4 is connected to the charging module (4).
4. The battery system with peak voltage suppression function according to claim 1, characterized in that, The charging module (4) includes a MOS transistor Q5 and a charging control unit (41). The drain of the MOS transistor Q5 is connected to the discharge module (3), the gate of the MOS transistor Q5 is connected to the charging control unit (41) and the control unit (51), and the source of the MOS transistor Q5 is connected to the charging control unit (41) and the negative output terminal. The input terminal of the charging control unit (41) is connected to the MCU (2), and the output terminal of the charging control unit (41) is connected to the MOS transistor Q5 and the negative output terminal.
5. The battery system with peak voltage suppression function according to claim 1, characterized in that, The control unit (51) includes a comparator U1, a voltage divider assembly (511), a first current limiting assembly (512), a pull-up resistor R16, a second current limiting assembly (513), a MOSFET Q8, and a second gate drive unit (514). The comparator U1 has a non-inverting input terminal IN+ and an inverting input terminal IN-. One end of the voltage divider assembly (511) is connected to the MCU (2), and the other end is connected to the non-inverting input terminal IN+. One end of the first current limiting assembly (512) is connected to the inverting input terminal IN-, and the other end is connected to the charging module (4). One end of the pull-up resistor R16 is connected to... The inverting input terminal IN- and the first current limiting component (512) are connected at their other ends to the second current limiting component (513) and the drain of the MOS transistor Q8, respectively. The other end of the second current limiting component (513) is connected to the second power supply voltage. The gate of the MOS transistor Q8 is connected to the MCU (2), and the source of the MOS transistor Q8 is connected to the VSS terminal of the comparator U1. The VCC terminal of the comparator U1 is connected to the first power supply voltage. The output terminal of the comparator U1 is connected to the second gate driving unit (514), and the second gate driving unit (514) is connected to the freewheeling unit (52).
6. The battery system with peak voltage suppression function according to claim 1, characterized in that, The freewheeling unit (52) includes a MOSFET Q7 and a MOSFET Q6. The drain of the MOSFET Q7 is connected to the energy storage unit (53), and the gate of the MOSFET Q7 is connected to the control unit (51). The gate of the MOSFET Q6 is connected to the control unit (51), and the drain of the MOSFET Q6 is connected to the source of the MOSFET Q7. The source of the MOSFET Q6 is connected to the charging module (4) and the negative output terminal, respectively.
7. The battery system with peak voltage suppression function according to claim 1, characterized in that, The energy storage unit (53) includes capacitor C1 and capacitor C2. One end of capacitor C1 is connected to the positive output terminal and capacitor C2 respectively, and the other end is connected to the freewheeling unit (52) and capacitor C2 respectively.
8. The battery system with peak voltage suppression function according to claim 4, characterized in that, The charging control unit (41) includes a first control component (411), a second control component (412), diodes D1 and D2, and a discharging component (413). The first control component (411), the second control component (412), and the discharging component (413) each have a first terminal, a second terminal, and a third terminal. The first terminal of the first control component (411) is connected to the MCU (2), the second terminal of the first control component (411) is connected to the first terminal of the second control component (412), and the third terminal of the first control component (411) is grounded. The second terminal of the second control component (412) is connected to the first terminal of the second control component (412). The second terminal is connected to the first power supply voltage. The third terminal of the second control component (412) is connected to the positive terminal of the diode D1. The negative terminal of the diode D1 is connected to the positive terminal of the diode D2 and the first terminal of the discharge component (413). The negative terminal of the diode D2 is connected to the control unit (51), the second terminal of the discharge component (413), and the gate of the MOS transistor Q5. The second terminal of the discharge component (413) is connected to the control unit (51) and the gate of the MOS transistor Q5. The third terminal of the discharge component (413) is connected to the source of the MOS transistor Q5 and the negative output terminal.
9. The battery system with peak voltage suppression function according to claim 8, characterized in that, The first control component (411) includes a MOSFET Q1, a resistor R1 and a resistor R2, and the second control component (412) includes a transistor Q2, a resistor R3 and a resistor R4. One end of the resistor R1 is connected to the MCU (2), and the other end is connected to the gate of the resistor R2 and the MOSFET Q1 respectively. The source of the MOSFET Q1 and the other end of the resistor R2 are grounded together. The drain of the MOSFET Q1 is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the base of the resistor R4 and the transistor Q2 respectively. The other end of the resistor R4 and the emitter of the transistor Q2 are connected to the first power supply voltage. The collector of the transistor Q2 is connected to the positive terminal of the diode D1.
10. The battery system with peak voltage suppression function according to claim 8, characterized in that, The discharge assembly (413) includes a transistor Q3, a resistor R7, and a resistor R6. The base of the transistor Q3 is connected to the cathode of the diode D1 and the anode of the diode D2, respectively. The emitter of the transistor Q3 is connected to the control unit (51) and the gate of the MOS transistor Q5, respectively. The collector of the transistor Q3 is connected to one end of the resistor R7, and the other end of the resistor R7 is connected to the source of the MOS transistor Q5. One end of the resistor R6 is connected to the base of the transistor Q3, and the other end of the resistor R6 is connected to the resistor R7 and the source of the MOS transistor Q5, respectively.