Vehicle-mounted battery energy management and protection system, method and computer program product

Abstract

The invention discloses a vehicle-mounted storage battery energy management and protection system and method, and the system comprises a state detection module which is used for collecting the charging state data of a lithium ion battery pack in real time when the lithium ion battery pack is charged through a generator; the charging loop module is used for limiting the charging current of the lithium ion battery pack through a charging current-limiting loop; large-current charging is performed on the lithium ion battery pack through the main charging loop; and the main control module is used for controlling the switching between the charging current-limiting loop and the main charging loop according to the charging state data of the lithium ion battery pack. According to the invention, a current-limiting loop is added to an existing power supply loop, so that the problems of large-current charging and overvoltage protection of the lithium ion battery in a battery feed state and a floating charge state are avoided, and reliable operation of a whole set of power supply and distribution system is ensured.

Description

Technical Field

[0001] The present invention relates to the field of vehicle-mounted batteries, and in particular to a vehicle-mounted battery energy management and protection system and method. Background Art

[0002] Whether it's a traditional fuel-powered vehicle or a new energy vehicle, a low-voltage battery is essential to ensure the proper functioning of the vehicle's low-voltage system. Lead-acid batteries, as onboard energy storage units, have a history of over a century, serving as power and starting components for traditional fuel-powered engines. With advances in lithium-ion battery technology, lead-acid batteries are no longer able to meet the growing trend toward electrified, intelligent, and lightweight vehicles due to significant drawbacks such as environmental damage during manufacturing, low specific energy, and a short cycle life.

[0003] The generator of a traditional engine generates electricity by belt-driven excitation generator fixed to the front end of the engine, and converts three-phase AC into DC through a rectifier bridge for use in the vehicle's electrical appliances. Due to installation layout limitations, the motor power of this type of generator is generally small, not exceeding 4KW. For vehicles with different purposes, the lead-acid batteries equipped with motors have capacities of 110Ah, 165Ah, and 200A. Due to the internal resistance characteristics of the lead-acid battery itself, the maximum charging rate of the lead-acid battery will not exceed 1C, that is, the corresponding charging currents of several mainstream lead-acid batteries are 110A, 165A, and 200A. This current will not cause much damage to the vehicle's motor. If it is replaced with a lithium-ion battery pack of the corresponding capacity, the following two problems will arise: Overcurrent and burning of the generator: The charge and discharge rates of lithium-ion batteries are much higher than those of lead-acid batteries. The maximum charge rate of a lithium-ion battery of the same capacity is more than three times that of a lead-acid battery. This will cause the generator to operate at a power level exceeding the rated power for a long time during the initial engine startup when the lithium-ion battery is low, eventually leading to thermal failure and burning. Triggering lithium-ion battery protection: When the vehicle is running for a long time, the lithium-ion battery is in a floating charge state. When there is a large current fluctuation, some lithium-ion batteries will be overcharged in a high SOC state, which will trigger overvoltage protection and cause the lithium-ion battery pack to lose power. Power loss during vehicle driving is not allowed. Summary of the Invention

[0004] The purpose of the present invention is to provide an on-board battery energy management and protection system on the one hand, and to provide an on-board battery energy management and protection method on the other hand. The system and method can solve the technical difficulties that arise in the process of replacing lead-acid batteries with lithium-ion batteries. By adding a current limiting circuit to the existing power supply circuit, it is ensured that the lithium-ion battery will not have high current charging and overvoltage protection problems in the battery feeding state and floating charge state, thereby ensuring the reliable operation of the entire power supply and distribution system.

[0005] To achieve this purpose, the present invention provides an on-vehicle battery energy management and protection system, which includes: The status detection module is used to collect the charging status data of the lithium-ion battery pack in real time when the generator is used to charge the lithium-ion battery pack; The charging circuit module is used to limit the charging current of the lithium-ion battery pack through the charging current limiting circuit; and to charge the lithium-ion battery pack with a high current through the main charging circuit; The main control module is used to control the switching between the charging current limiting circuit and the main charging circuit according to the charging status data of the lithium-ion battery pack.

[0006] Furthermore, the charging current limiting circuit includes an input voltage Ui, a MOS tube Q, a diode D, an inductor L, a resistor R, and a capacitor C. When the MOS tube Q is turned on, the input voltage Ui is the voltage output by the low-voltage bus, the low-voltage bus current flows into the drain of the MOS tube Q, and the low-voltage bus current flows into the inductor L through the source of the MOS tube Q, and then flows into the negative electrode of the input voltage Ui through the resistor R. When the MOS tube Q switches from the on state to the off state, the current stored in the inductor L flows through the resistor R, flows into the negative electrode of the diode D, and flows into the inductor L through the positive electrode of the diode D. The capacitor C is used to maintain the stability of the output voltage and perform voltage low-pass filtering. The voltage across the resistor R is the output voltage Uo.

[0007] Furthermore, the main charging circuit is composed of a charging MOS tube.

[0008] Furthermore, it also includes a supercapacitor assembly module, which is used to use the supercapacitor assembly to stabilize the voltage of the lithium-ion battery pack and the generator. The supercapacitor assembly is composed of multiple capacitors connected in series. The supercapacitor assembly and the lithium-ion battery pack are connected in parallel between the positive and negative poles of the low-voltage bus at the voltage output end of the generator.

[0009] Furthermore, a vehicle-mounted battery energy management and protection method based on the vehicle-mounted battery energy management and protection system includes: Determine whether the state of the lithium-ion battery pack is suitable for high-current charging or low-current charging based on the charging state data of the lithium-ion battery pack; When the lithium-ion battery pack is suitable for high-current charging, the main charging circuit is turned on and the lithium-ion battery pack is charged with high current through the main charging circuit. When the lithium-ion battery pack is suitable for low-current charging, the charging current limiting circuit is turned on and the lithium-ion battery pack is charged with low current through the charging current limiting circuit.

[0010] Furthermore, the charging status data of the lithium-ion battery pack includes the voltage value, temperature value, charging current, SOC value, and number of current overcharges of the lithium-ion battery pack, wherein the voltage value, temperature value, and charging current are all acquired by sensors, and the SOC value is automatically calculated by the main control module based on the voltage value, temperature value, and charging current of the lithium-ion battery pack. The number of overcharges is the number of times the charging current of the lithium-ion battery exceeds a preset current threshold. Furthermore, a method for determining whether the state of the lithium-ion battery pack is suitable for high-current charging based on the charging status data of the lithium-ion battery pack includes: comparing the voltage value, temperature value, and charging current of the lithium-ion battery pack with a preset first voltage threshold, a preset first temperature threshold, and a preset current threshold, respectively; when the voltage value and temperature value of the lithium-ion battery pack are respectively greater than or equal to the first voltage threshold and the first temperature threshold, and the charging current of the lithium-ion battery pack is less than or equal to the preset current threshold, the lithium-ion battery pack is suitable for high-current charging.

[0011] Furthermore, the method for determining whether the state of a lithium-ion battery pack is suitable for low-current charging based on the charging state data of the lithium-ion battery pack includes: comparing the SOC value and the number of current overcharges of the lithium-ion battery with a preset SOC threshold and a current overcharge number threshold, respectively; when the SOC value and the number of current overcharges of the lithium-ion battery exceed the preset SOC threshold and the current overcharge number threshold, respectively, the lithium-ion battery pack is suitable for low-current charging; and comparing the voltage value and the temperature value of the lithium-ion battery pack with a preset second voltage threshold and a second temperature threshold, respectively; when the voltage value and / or the temperature value exceed the preset second voltage threshold and the second temperature threshold, respectively, the lithium-ion battery pack is suitable for low-current charging.

[0012] Furthermore, the method for controlling the conduction of the main charging circuit and the current-limiting charging circuit includes: when the lithium-ion battery pack is suitable for high-current charging, the main control module applies a conduction voltage to the charging MOS tube of the main charging circuit to turn on the main charging circuit; when the lithium-ion battery pack is suitable for low-current charging, the main control module applies a conduction voltage to the MOS tube of the charging current-limiting circuit to turn on the charging current-limiting circuit.

[0013] Beneficial effects of the present invention: The present invention addresses the shortcomings of low-voltage lithium-ion batteries with poor abuse resistance, especially the damage to the silicon generator caused by the initial large current when replacing lead-acid batteries, and the overvoltage protection problem caused by the large current at the end of charging. The invention independently designs a protection and control circuit suitable for low-voltage lithium-ion battery packs to ensure that the low-voltage lithium-ion battery packs can operate reliably: The present invention adds a charging current limiting circuit and a group of supercapacitor components to the existing power supply circuit to achieve lithium-ion battery protection for silicon generators and lithium-ion battery cells in the initial charging stage and the floating charge stage at the end of charging; the supercapacitor is used to filter and stabilize the silicon generator to achieve stable power supply for the entire vehicle; the supercapacitor group can also filter the peak voltage of the silicon generator to avoid ripple damage to the life of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit topology diagram of the power management system of the present invention; Figure 2 is a topological diagram of the current limiting circuit of the present invention; Figure 3 The control logic diagram of the battery management system of the present invention is Figure 4 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: like Figure 4 As shown, a vehicle-mounted battery energy management and protection system includes: The status detection module is used to collect the charging status data of the lithium-ion battery pack in real time when the generator is used to charge the lithium-ion battery pack; The charging circuit module is used to limit the charging current of the lithium-ion battery pack through the charging current limiting circuit; and to charge the lithium-ion battery pack with a high current through the main charging circuit; The main control module is used to control the switching between the charging current limiting circuit and the main charging circuit according to the charging status data of the lithium-ion battery pack.

[0017] With advances in lithium-ion battery technology, lead-acid batteries are no longer able to meet the growing trend toward electrified, intelligent, and lightweight vehicles due to significant drawbacks such as environmental damage during manufacturing, low specific energy, and short cycle life. Lithium-ion batteries are gradually replacing traditional lead-acid batteries as onboard energy storage units. However, traditional generators powering lead-acid batteries have low power consumption. When charging lithium-ion batteries, the charge and discharge rates are much higher than those of lead-acid batteries, causing the generators to operate at power levels exceeding their rated power for extended periods, ultimately leading to thermal failure and burnout. Furthermore, when vehicles operate for extended periods, the lithium-ion batteries are in a floating charge state. When subjected to high current fluctuations, some lithium-ion cells can overcharge at high SOC levels, triggering overvoltage protection and causing the lithium-ion battery pack to shut down. To address the technical difficulties associated with replacing lead-acid batteries with lithium-ion batteries, a current limiting circuit is added to the existing power supply circuit to ensure that high current charging and overvoltage protection are not applied to the lithium-ion batteries during battery feed and floating charge states, ensuring reliable operation of the entire power supply and distribution system.

[0018] In some embodiments, as Figure 1 As shown, the power management system includes a battery pack, a PTC heating control module, an integrated main control module, a voltage and temperature detection module, a current detection module, a current limiting module, a charging MOSFET, and a communication and fault diagnosis module. The battery pack is composed of multiple lithium-ion battery cells with a specific voltage and capacity. The PTC heating control module provides auxiliary heating in low-temperature environments, enabling rapid heating of the battery pack. The voltage and temperature detection module monitors the battery pack's cell voltage and temperature in real time. The current detection module monitors the battery pack's charge and discharge currents in real time. The communication and fault diagnosis module facilitates communication between the battery pack and the vehicle or other systems, as well as troubleshooting. The main control module performs relevant calculations based on battery pack and cell status information and controls the charging MOSFET to implement charging protection and current limiting strategies for different battery pack states, ensuring safe and efficient battery operation. B+ and B- are the positive and negative terminals of the low-voltage DC bus, respectively. The low-voltage DC bus has voltages of 12V and 24V. One end of the low-voltage DC bus connects to the generator's voltage output terminal, and the other end connects to the lithium-ion battery pack's voltage input terminal, enabling the generator to power the lithium-ion battery pack.

[0019] In some technical solutions, the topology of the charging current limiting circuit includes an input voltage Ui, a MOS transistor Q, a diode D, an inductor L, a resistor R, and a capacitor C. When the MOS transistor Q is turned on, the input voltage Ui is the voltage output by the low-voltage bus, and the low-voltage bus current flows into the drain of the MOS transistor Q. After the low-voltage bus current flows into the inductor L through the source of the MOS transistor Q, it flows into the negative electrode of the input voltage Ui through the resistor R. When the MOS transistor Q switches from the on state to the off state, the current stored in the inductor L flows through the resistor R, flows from the negative electrode of the diode D, and flows into the inductor L through the positive electrode of the diode D. The capacitor C is used to maintain the stability of the output voltage and perform voltage low-pass filtering. The voltage across the resistor R is the output voltage Uo. Equivalent circuit implementation structures designed using the charging current limiting circuit of the above topology all fall within the scope of protection of the present invention. It is understandable that there are alternative circuit structures for enabling the MOS transistor Q as a switch tube, and other circuit structures equivalent to the on-off enabling of the above switch tube also fall within the scope of protection of the present invention.

[0020] like Figure 2 As shown, the positive electrode of the input voltage Ui is connected to the drain of the MOS tube Q, the source of the MOS tube Q is connected to one end of the inductor L, the other end of the inductor L is connected to one end of the capacitor C, the other end of the capacitor C is connected to the positive electrode of the diode D, the negative electrode of the diode is connected to one end of the inductor L, one end of the capacitor C is connected to one end of the resistor R, the other end of the capacitor C is connected to the other end of the resistor R, and the drain of the MOS tube Q is connected to the other end of the resistor R.

[0021] The MOS tube Q is used to control the conduction and disconnection of the current-limited charging circuit. The resistor R is used to consume power and limit the current output value. In some embodiments, the current allowed to pass through the current-limited charging circuit is set to 10A. The charging current limit value can be set according to the battery pack capacity and the actual usage environment. The resistance value of the resistor R is calculated according to the voltage difference between the input voltage and the output voltage of the low-voltage DC bus and the charging current limit value using Ohm's law.

[0022] In some technical solutions, the main charging circuit is composed of a charging MOS tube.

[0023] MOS transistors have low conduction losses and high-frequency switching characteristics. Using MOS transistors as the main charging circuit reduces power consumption, resulting in higher energy utilization for the generator. Furthermore, their small size simplifies the structure of the power management system. When a lithium-ion battery pack or generator fails, the MOS transistors can quickly respond and control, quickly cutting off the current. The main charging circuit consists of one or more charging MOS transistors.

[0024] In some technical solutions, the on-board battery energy management and protection system also includes a supercapacitor assembly module, which is used to utilize the supercapacitor assembly to perform voltage stabilization protection on the lithium-ion battery pack and the generator. The supercapacitor assembly is composed of multiple capacitors in series, and the supercapacitor assembly and the lithium-ion battery pack are connected in parallel between the positive and negative poles of the low-voltage bus at the voltage output end of the generator.

[0025] In some embodiments, the supercapacitor assembly can be, but is not limited to, composed of 12 capacitors with a capacity of 300f. The supercapacitor assembly composed of multiple capacitors in series has greatly improved voltage resistance and voltage regulation capabilities. The voltage stabilization function of the supercapacitor assembly is utilized to avoid the peak voltage of the generator damaging the service life of the lithium-ion battery pack when the lithium-ion battery pack is normally charged, and to avoid damage to the generator due to sudden current changes when the lithium-ion battery pack is disconnected due to a fault.

[0026] Example 2 An on-vehicle battery energy management and protection method based on the on-vehicle battery energy management and protection system includes: Determine whether the state of the lithium-ion battery pack is suitable for high-current charging or low-current charging based on the charging state data of the lithium-ion battery pack; When the lithium-ion battery pack is suitable for high-current charging, the main charging circuit is turned on and the lithium-ion battery pack is charged with high current through the main charging circuit. When the lithium-ion battery pack is suitable for low-current charging, the charging current limiting circuit is turned on and the lithium-ion battery pack is charged with low current through the charging current limiting circuit.

[0027] like Figure 3 As shown, the battery management system control logic includes the following steps: S1: Battery pack charging begins. While the battery pack is charging, the battery management system monitors the battery pack and individual cell charging status data in real time and transmits it to the main control module, providing a basis for executing the charging current limit strategy. During the initial charging phase, the battery pack charges at the charging current limit, which can be set based on the battery pack capacity and actual usage environment. The charging current limit can be, but is not limited to, 10A.

[0028] In some technical solutions, the charging status data of the lithium-ion battery pack includes the voltage, temperature, charging current, SOC value, and number of current overcharges of the lithium-ion battery pack. The voltage, temperature, and charging current are all acquired by sensors. The SOC value is automatically calculated by a main control module based on the voltage, temperature, and charging current of the lithium-ion battery pack. The number of overcharges is the number of times the charging current of the lithium-ion battery exceeds a preset current threshold. In some technical solutions, a method for determining whether the lithium-ion battery pack is suitable for high-current charging based on the charging status data of the lithium-ion battery pack includes: comparing the voltage, temperature, and charging current of the lithium-ion battery pack with a preset first voltage threshold, a preset first temperature threshold, and a preset current threshold, respectively. When the voltage and temperature of the lithium-ion battery pack are respectively greater than or equal to the first voltage threshold and the first temperature threshold, and the charging current of the lithium-ion battery pack is less than or equal to the preset current threshold, the lithium-ion battery pack is suitable for high-current charging. The charging current is the charging current output by the generator to the lithium-ion battery pack. High-current charging means that the charging current of the lithium-ion battery pack is the rated current of the generator.

[0029] Specifically, the steps of determining whether the lithium-ion battery pack needs high current charging include: S2: Determine whether the battery voltage is greater than or equal to a first voltage threshold. If so, proceed to step S3; if not, proceed to step S1. Voltage threshold I is preset to a lower limit of 24V for the total battery pack voltage or 3V for the battery cell voltage. The specific value can be set based on battery performance parameters and actual usage environment. The first voltage threshold is set to prevent overcharging of the lithium-ion battery pack due to high current charging at low SOC.

[0030] S3: Determine whether the battery temperature is greater than or equal to a first temperature threshold. If so, proceed to step S4; if not, proceed to step S2. The first temperature threshold is preset to the lower limit of the battery cell temperature of 0°C or the lower limit of the average battery cell temperature of 0°C. The specific value can be set based on battery performance parameters and actual usage environment. The first temperature threshold is set to prevent low-temperature, high-current charging from damaging the life of the lithium-ion battery pack and reducing the capacity of the lithium-ion battery pack.

[0031] S4: Determine whether the charging current is less than or equal to a current threshold. If not, proceed to step S5; if so, close the current limiting circuit and initiate high-current charging. The current threshold is preset to the maximum value allowed for high-current charging, i.e., the rated current of the generator. The rated current of the generator may range from 120A, 150A, 180A, 240A, etc., depending on the motor specifications. The specific value can be set based on the battery pack performance parameters and actual usage environment. Setting the current threshold prevents high-current charging of the lithium-ion battery pack at a low SOC, which may cause the generator to operate at a power level exceeding its rated power for extended periods. During the initial charging phase of the lithium-ion battery pack, the lithium battery's ability to accept charge at low SOC is very strong, exceeding the generator's power generation capacity. Consequently, the charging current of the lithium-ion battery pack may exceed the rated current of the generator. When the charging current of the lithium-ion battery pack, as measured by the current sensor, exceeds the rated current of the generator, the main control module controls the MOSFET in the main charging circuit to disconnect and the MOSFET in the charging current limiting circuit to conduct, charging the lithium-ion battery pack with a low current. This prevents the generator from operating at a power level exceeding its rated power for extended periods, which could ultimately lead to thermal failure and burnout.

[0032] In some technical solutions, a method for determining whether a lithium-ion battery pack is suitable for low-current charging based on charging status data of the lithium-ion battery pack includes: comparing the state of charge (SOC) value and the number of current overcharges of the lithium-ion battery with a preset SOC threshold and a current overcharge threshold, respectively; when the SOC value and the number of current overcharges of the lithium-ion battery exceed the preset SOC threshold and the current overcharge threshold, respectively, the lithium-ion battery pack is suitable for low-current charging; and comparing the voltage value and the temperature value of the lithium-ion battery pack with a preset second voltage threshold and a second temperature threshold, respectively; when the voltage value and / or the temperature value exceed the preset second voltage threshold and the second temperature threshold, respectively, the lithium-ion battery pack is suitable for low-current charging. Low-current charging refers to the charging current of the lithium-ion battery pack being the current output by the current-limiting charging circuit.

[0033] Specifically, the steps of determining whether the lithium-ion battery pack needs low-current charging include: S5: Determine whether the SOC value is less than or equal to the protection threshold. If so, proceed to step S6; if not, activate the charging current limit circuit, disconnect the main circuit, and record the number of overcharges N. At this point, a charging overcurrent occurs, and determine whether the number of overcharges N is greater than or equal to the overcharge threshold. The protection threshold includes, but is not limited to, 80% or 95%, and the overcharge threshold includes, but is not limited to, integers of 1, 2, or 3, which can be preset based on the battery pack's performance parameters. If the number of overcharges N does not exceed the overcharge threshold, then extend the time T and proceed to step S1 to continue the determination. If the number of overcharges N exceeds the overcharge threshold, an alarm is output, and the charging current limit function is activated, commencing low-current charging. Each time an overcharge is detected, a period of T is required to remain idle to prevent abnormal polarization of the lithium-ion battery caused by excessive system current. This period of T allows the polarization voltage caused by the abnormal current to recover, helping to avoid false system fault alarms. The extended time T can be determined by the time it takes to resume charging after a charging interruption. T can be calibrated based on actual conditions and is generally 1-2 minutes.

[0034] In the later stage of charging of the lithium-ion battery pack, the SOC value of the battery pack will rise. In order to prevent the lithium-ion battery pack from overcharging when charging with a large current in a high SOC state, the lithium-ion battery will be overcharged in a high SOC state, thereby triggering the main control module to perform overvoltage protection on the lithium-ion battery pack, causing the lithium-ion battery pack to power off. The SOC threshold and current overcharge count threshold are set to protect the lithium-ion battery pack from overcharging. The current overcharge count is the number of times the charging current of the lithium-ion battery pack exceeds the current threshold. The battery pack SOC value and current overcharge count are automatically calculated by the main control module.

[0035] S6: Determine whether the battery temperature is less than or equal to the second temperature threshold. If so, proceed to step S7; if not, enable the charging current limit function and begin low-current charging. Temperature threshold II is preset to the upper limit of the battery cell temperature of 55°C or the upper limit of the average battery cell temperature of 55°C. The specific value can be set based on battery performance parameters and actual usage environment. The second temperature threshold is used to prevent the lithium-ion battery pack from charging with high current at high temperatures, which may shorten the service life of the lithium-ion battery pack.

[0036] S7: Determine whether the battery voltage is greater than or equal to the second voltage threshold. If not, proceed to step S5 to continue the determination. If so, enable the charging current limit function and begin low-current charging. Voltage Threshold II is preset to the upper limit of 28V for the total battery pack voltage or 3.5V for the upper limit of the battery cell voltage. The specific value can be set based on battery performance parameters and actual usage environment. The power management system controls the operation in a loop according to this logic. The second voltage threshold is used to prevent overcharging of the lithium-ion battery pack when charging at high current at high SOC.

[0037] The power management system controls the operation in a loop according to steps S1 to S8.

[0038] The method for controlling the conduction of the main charging circuit and the current-limiting charging circuit includes: when the lithium-ion battery pack is suitable for high-current charging, the main control module applies a conduction voltage to the charging MOS tube of the main charging circuit to make the main charging circuit conductive; when the lithium-ion battery pack is suitable for low-current charging, the main control module applies a conduction voltage to the MOS tube of the charging current-limiting circuit to make the charging current-limiting circuit conductive.

[0039] The voltage and temperature detection module and the current detection module collect the voltage, temperature and current information of the lithium-ion battery pack. The main control module determines the charging status of the lithium-ion battery pack based on the voltage, temperature and current of the lithium-ion battery pack, applies a conduction voltage to the MOS tube of the charging current limiting circuit or the main charging circuit, and controls the conduction of the charging current limiting circuit or the main charging circuit.

[0040] When the main control module applies a conduction voltage to the MOS tube of the charging current limiting circuit, the charging current limiting circuit is turned on; when the main control module applies a conduction voltage to the MOS tube of the main charging circuit, the main charging circuit is turned on.

[0041] Example 3 The present invention also includes a computer program product comprising a computer program / instructions that, when executed by a processor, implement the steps of the above-described vehicle battery energy management and protection method. In embodiments, the above-described program includes, but is not limited to, being executed in a vehicle battery management system.

[0042] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A vehicle-mounted battery energy management and protection system, characterized in that: It includes: The status detection module is used to collect the charging status data of the lithium-ion battery pack in real time when the generator is used to charge the lithium-ion battery pack; The charging circuit module is used to limit the charging current of the lithium-ion battery pack through the charging current limiting circuit; and to charge the lithium-ion battery pack with a high current through the main charging circuit; The main control module is used to control the switching between the charging current limiting circuit and the main charging circuit according to the charging status data of the lithium-ion battery pack.

2. The vehicle-mounted battery energy management and protection system according to claim 1, characterized in that: The charging current limiting circuit includes an input voltage Ui, a MOS transistor Q, a diode D, an inductor L, a resistor R, and a capacitor C. When the MOS transistor Q is turned on, the input voltage Ui is the voltage output by the low-voltage bus, the low-voltage bus current flows into the drain of the MOS transistor Q, the low-voltage bus current flows into the inductor L through the source of the MOS transistor Q, and then flows into the negative electrode of the input voltage Ui through the resistor R. When the MOS transistor Q switches from the on state to the off state, the current stored in the inductor L flows through the resistor R, flows into the negative electrode of the diode D, and flows into the inductor L through the positive electrode of the diode D. The capacitor C is used to maintain the stability of the output voltage and perform voltage low-pass filtering. The voltage across the resistor R is the output voltage Uo.

3. The vehicle-mounted battery energy management and protection system according to claim 1, characterized in that: The main charging circuit is composed of a charging MOS tube.

4. The vehicle-mounted battery energy management and protection system according to claim 1, characterized in that: It also includes a supercapacitor assembly module, which is used to use the supercapacitor assembly to stabilize the voltage of the lithium-ion battery pack and the generator. The supercapacitor assembly is composed of multiple capacitors in series. The supercapacitor assembly and the lithium-ion battery pack are connected in parallel between the positive and negative poles of the low-voltage bus at the voltage output end of the generator.

5. A vehicle-mounted battery energy management and protection method based on the vehicle-mounted battery energy management and protection system according to claim 1, characterized in that: It includes: Determine whether the state of the lithium-ion battery pack is suitable for high-current charging or low-current charging based on the charging state data of the lithium-ion battery pack; When the lithium-ion battery pack is suitable for high-current charging, the main charging circuit is turned on and the lithium-ion battery pack is charged with high current through the main charging circuit. When the lithium-ion battery pack is suitable for low-current charging, the charging current limiting circuit is turned on and the lithium-ion battery pack is charged with low current through the charging current limiting circuit.

6. The method for energy management and protection of a vehicle battery according to claim 5, characterized in that: The charging status data of the lithium-ion battery pack includes the voltage value, temperature value, charging current, SOC value and number of current overcharges of the lithium-ion battery pack. The voltage value, temperature value and charging current are all collected by sensors. The SOC value is automatically calculated by the main control module based on the voltage value, temperature value and charging current of the lithium-ion battery pack. The number of overcharges is the number of times the charging current of the lithium-ion battery exceeds a preset current threshold.

7. A vehicle-mounted battery energy management and protection method according to claim 5 or 6, characterized in that: A method for determining whether a state of a lithium-ion battery pack is suitable for high-current charging based on charging state data of the lithium-ion battery pack includes: comparing a voltage value, a temperature value, and a charging current of the lithium-ion battery pack with a preset first voltage threshold, a preset first temperature threshold, and a preset current threshold, respectively; when the voltage value and the temperature value of the lithium-ion battery pack are respectively greater than or equal to the first voltage threshold and the first temperature threshold, and the charging current of the lithium-ion battery pack is less than or equal to the preset current threshold, the lithium-ion battery pack is suitable for high-current charging.

8. The method for energy management and protection of a vehicle battery according to claim 5 or 6, characterized in that: The method for determining whether the state of a lithium-ion battery pack is suitable for low-current charging based on charging state data of the lithium-ion battery pack includes: comparing the state of charge (SOC) value and the number of current overcharges of the lithium-ion battery with a preset SOC threshold and a current overcharge number threshold, respectively; when the SOC value and the number of current overcharges of the lithium-ion battery exceed the preset SOC threshold and the current overcharge number threshold, respectively, the lithium-ion battery pack is suitable for low-current charging; and comparing the voltage value and the temperature value of the lithium-ion battery pack with a preset second voltage threshold and a second temperature threshold, respectively; when the voltage value and / or the temperature value exceed the preset second voltage threshold and the second temperature threshold, respectively, the lithium-ion battery pack is suitable for low-current charging.

9. The vehicle-mounted battery energy management and protection method according to claim 5, characterized in that: The method for controlling the conduction of the main charging circuit and the current-limiting charging circuit includes: when the lithium-ion battery pack is suitable for high-current charging, the main control module applies a conduction voltage to the charging MOS tube of the main charging circuit to make the main charging circuit conductive; when the lithium-ion battery pack is suitable for low-current charging, the main control module applies a conduction voltage to the MOS tube of the charging current-limiting circuit to make the charging current-limiting circuit conductive.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to claim 5 are implemented.

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