Charging control circuit and method for multiple groups of parallel power batteries and train

Abstract

The invention discloses a charging control circuit and method for multiple groups of parallel power batteries and a train. An energy management device determines a target charging voltage in real time according to battery voltage information of each power battery and controls a direct current converter to convert to the target charging voltage when the power battery performance is reduced and under-charging and over-charging conditions occur; and when the target charging voltage is reached, the controller controls the corresponding BUCK circuit to be switched on to charge the corresponding power battery. The energy management module controls the direct-current converter to convert to target charging voltage, so that the charging voltage is in a controllable range, the corresponding BUCK circuit is switched on to charge the power battery after the target charging voltage is reached, and the stability and safety of the charging process are ensured by monitoring battery voltage information in real time and adjusting the output voltage of the direct-current converter. Battery aging is reduced and the service life of the battery is prolonged. By accurately controlling the charging process, the energy waste is reduced.

Description

Technical Field

[0001] The present application relates to the field of charging technology, and in particular to a charging control circuit, method and train for multiple groups of parallel power batteries. Background Art

[0002] With the development of technology, rail transit vehicles have begun to use power batteries as reserve power for starting and acceleration, but their prices are relatively high and they need to further maintain their performance and extend their service life. However, the capacity of the battery will change with various factors.

[0003] Especially when multiple groups of power batteries are used in parallel, when one or more batteries are aged and their performance is lower than the expected level, if the batteries are still used in the same control method, some batteries may be overcharged or over-discharged, seriously shortening the life of the battery and even causing an accident.

[0004] It can be seen that how to solve the problems of undercharging and overcharging when the performance of power batteries decreases is a technical problem that needs to be solved urgently by people in this field. Summary of the invention

[0005] The purpose of the present application is to provide a charging control circuit, method and train for multiple groups of parallel power batteries to solve the problems of undercharging and overcharging when the battery performance deteriorates.

[0006] In order to solve the above technical problems, the present application provides a charging control circuit for multiple groups of parallel power batteries, which is applied to multiple groups of power batteries, including: a traction converter, a DC converter, and an energy management device, wherein the traction converter includes: multiple BUCK circuits and a controller;

[0007] The output end of the DC converter is connected to the intermediate DC circuit of the traction converter, and each of the BUCK circuits draws power from the intermediate DC circuit of the traction converter and is connected to each of the power batteries;

[0008] The battery management system of each power battery is connected to the energy management device, and the energy management device is connected to the controller; the energy management device is connected to the DC converter;

[0009] The energy management device determines the target charging voltage in real time according to the battery voltage information of each power battery, controls the DC converter to convert to the target charging voltage, and sends the charge state of the power battery to the controller; when the target charging voltage is reached, the controller controls the corresponding BUCK circuit to start charging the corresponding power battery.

[0010] As an optional solution, in the charging control circuit of the plurality of parallel power batteries, the traction converter further comprises: a plurality of current detection modules and a plurality of voltage detection modules;

[0011] The current detection module is connected between the positive electrode of each diode and the first end of the power battery; the voltage detection module is connected in parallel between the first end of the power battery and the second end of the power battery; each current detection module and each voltage detection module monitor the current information and voltage information of the corresponding power battery and send them to the controller;

[0012] The controller receives the current information sent by the current detection module and the voltage information sent by the voltage detection module, and adjusts the current and voltage of the BUCK circuit according to the current information and the voltage information.

[0013] As an optional solution, the charging control circuit of the plurality of parallel power batteries further includes: a plurality of diodes;

[0014] The cathode of each diode is connected to the first end of the intermediate DC circuit, the anode of each diode is connected to the first end of each power battery, and the second end of the intermediate DC circuit is connected to the second end of each power battery.

[0015] As an optional solution, in the charging control circuit of the above-mentioned multiple groups of parallel power batteries, the current detection module is connected between the positive electrode of each diode and the first end of the power battery; the voltage detection module is connected in parallel between the first end of the power battery and the second end of the power battery;

[0016] The controller receives the current information sent by the current detection module and the voltage information sent by the voltage detection module, and adjusts the current and voltage of the BUCK circuit according to the current information and the voltage information.

[0017] As an optional solution, the charging control circuit of the plurality of parallel power batteries further comprises: a plurality of reactors; each of the BUCK circuits is connected to each of the power batteries via the reactor;

[0018] The first end of each of the reactors is connected to the output end of the BUCK circuit, and the second end of the reactor is connected to the first end of the power battery.

[0019] As an optional solution, the charging control circuit of the plurality of parallel power batteries further includes: an IGBT control module;

[0020] The controller is connected to the IGBT control module and outputs a PWM control signal to the IGBT control module to control the on-time. The IGBT control module is connected to the BUCK circuit and adjusts the current and voltage of the BUCK circuit.

[0021] As an optional solution, the charging control circuit for the plurality of parallel power batteries further includes: a display device;

[0022] The display device is connected to the energy management device, receives the charging indication status, floating charge indication status, and power supply indication status sent by the energy management device, and displays corresponding status icons.

[0023] In order to solve the above technical problems, the present application also provides a charging control method for multiple groups of parallel power batteries, which is applied to a charging control circuit for multiple groups of parallel power batteries, including: a traction inverter, a DC converter, and an energy management device, wherein the traction inverter includes: multiple BUCK circuits and a controller; the output end of the DC converter is connected to the intermediate DC circuit of the traction inverter, and each of the BUCK circuits draws power from the intermediate DC circuit of the traction inverter and is connected to each of the power batteries; the battery management system of each of the power batteries is connected to the energy management device, and the energy management device is connected to the controller; the energy management device is connected to the DC converter; the method includes:

[0024] receiving the state of charge sent by the energy management device in real time;

[0025] When the target charging voltage is reached, the corresponding BUCK circuit is controlled to be turned on to charge the corresponding power battery until the state of charge reaches a preset threshold; wherein the energy management device determines the target charging voltage based on the battery voltage information of each power battery and then controls the DC converter to convert to reach the target charging voltage.

[0026] As an optional solution, the above-mentioned charging control method for multiple groups of parallel power batteries further includes:

[0027] Receive current information sent by the current detection module and voltage information sent by the voltage detection module;

[0028] Determining whether the current information and the voltage information meet the preset charging conditions of the current power battery;

[0029] If not, the current and voltage of the BUCK circuit are adjusted according to the current information and the voltage information.

[0030] As an optional solution, the above-mentioned charging control method for multiple groups of parallel power batteries further includes:

[0031] Real-time monitoring of whether the state of charge reaches a preset threshold;

[0032] If yes, control the BUCK circuit to switch to a floating charge state;

[0033] The charging current of the BUCK circuit is controlled to decrease to a preset minimum threshold.

[0034] As an optional solution, in the above-mentioned charging control method for multiple groups of parallel power batteries, the energy management device determines the target charging voltage according to the battery voltage information of each power battery and then controls the DC converter to convert to reach the target charging voltage, including:

[0035] Receiving battery voltage information sent by the battery management system of each of the power batteries;

[0036] Obtaining a target charging voltage according to the battery voltage information and a preset charging voltage difference;

[0037] The DC converter is controlled to convert according to the target charging voltage until the target charging voltage is reached.

[0038] As an optional solution, in the above-mentioned charging control method for multiple groups of parallel power batteries, the current and voltage of the BUCK circuit are adjusted according to the current information and the voltage information, including:

[0039] Generate a PWM control signal for adjusting the voltage and current according to the current information and the voltage information;

[0040] The on-time of the IGBT control module is controlled according to the PWM control signal to adjust the current and voltage of the BUCK circuit.

[0041] In order to solve the above technical problems, the present application also provides a train, including the charging control circuit of the above-mentioned multiple groups of parallel power batteries.

[0042] The charging control circuit of multiple groups of parallel power batteries provided in the present application, the energy management device determines the target charging voltage in real time according to the battery voltage information of each power battery, controls the DC converter to convert to the target charging voltage, and sends the charge state of the power battery to the controller; when the target charging voltage is reached, the controller controls the corresponding BUCK circuit to open and charge the corresponding power battery. In the present application, the energy management module controls the DC converter to convert to the target charging voltage so that the charging voltage is within a controllable range. After reaching the target charging voltage, the corresponding BUCK circuit is opened to charge the power battery. By adjusting the output voltage of the DC converter in real time, overcharging or over-discharging caused by excessive voltage difference during charging is avoided, ensuring the stability and safety of the charging process, reducing battery aging, and extending the battery life. By precisely controlling the charging process, energy waste is reduced.

[0043] In addition, the present application also provides a charging control method for multiple groups of parallel power batteries and a train, which correspond to the charging control circuit for the above-mentioned multiple groups of parallel power batteries and have the same effect as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of a charging control circuit for multiple groups of parallel power batteries provided in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of an IGBT control module provided in an embodiment of the present application;

[0047] Figure 3 A flow chart of a charging control method for multiple groups of parallel power batteries provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] The core of this application is to provide a charging control circuit, method and train for multiple groups of parallel power batteries.

[0050] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0051] Power batteries are power sources for tools, mostly referring to batteries that power electric vehicles, electric trains, electric bicycles, and golf carts. With the development of technology, rail transit vehicles have begun to use power batteries as reserve power for starting and acceleration, but the capacity of the battery will change with various factors. Especially when multiple groups of power batteries are used in parallel, when one or more batteries are aged and below the expected performance level, the same control method may be used to use the batteries, which may cause some batteries to be overcharged or over-discharged, severely shortening the life of the battery and even causing an accident.

[0052] The present application does not limit the type of power battery, such as lead-acid battery, lithium iron phosphate battery, fuel cell, etc.

[0053] In order to solve the above problems, the embodiment of the present application provides a charging control circuit for multiple groups of parallel power batteries, which is applied to multiple groups of power batteries. Figure 1 A schematic diagram of a charging control circuit for multiple groups of parallel power batteries provided in an embodiment of the present application, such as Figure 1 As shown, it includes: a traction converter 11, a DC converter 12, and an energy management device 13, wherein the traction converter 11 includes: a plurality of BUCK circuits 111 and a controller 114;

[0054] The output end of the DC converter 12 is connected to the intermediate DC circuit of the traction converter 11, and each BUCK circuit 111 draws power from the intermediate DC circuit of the traction converter 11 and is connected to each power battery;

[0055] The battery management system of each power battery is connected to the energy management device 13, and the energy management device 13 is connected to the controller 114; the energy management device 13 is connected to the DC converter 12;

[0056] The energy management device 13 determines the target charging voltage in real time according to the battery voltage information of each power battery, controls the DC converter 12 to convert to the target charging voltage, and sends the charge state of the power battery to the controller 114; when the target charging voltage is reached, the controller 114 controls the corresponding BUCK circuit 111 to start charging the corresponding power battery.

[0057] In this embodiment, the traction inverter 11 refers to an electric device whose function is to convert the input AC or DC power into an electric energy form suitable for the traction motor. In this solution, the traction inverter 11 includes a plurality of BUCK circuits 111 and a controller 114 in addition to the conventional structure. The DC converter 12 is an electric device that converts a DC voltage into another DC voltage. In this solution, the output end of the DC converter 12 is connected to the intermediate DC circuit of the traction inverter 11 to ensure a stable supply of power. The output DC voltage is transmitted to the inverter through the intermediate DC circuit, and the traction motor is powered by the inverter to drive the vehicle to run.

[0058] The buck converter circuit (BUCK circuit) refers to a switching type voltage regulator, whose main function is to convert a higher input voltage into a lower output voltage and provide a stable output voltage. In this solution, the BUCK circuit 111 draws power from the intermediate DC circuit of the traction converter 11, connects to each power battery, and charges each power battery.

[0059] The energy management device 13 determines the target charging voltage to be achieved according to the voltage information of the power battery, and controls the DC converter 12 to convert to the target charging voltage to avoid overcharging or overdischarging caused by the voltage difference between the charging voltage and the battery voltage being too large or too small. In this solution, the energy management device 13 is connected to the battery management system of the power battery and sends the state of charge to the controller 114. The controller 114 controls the BUCK circuit 111 to charge the power battery according to the state of charge until the target state of charge is reached.

[0060] Specifically, multiple groups of power batteries are charged in sequence.

[0061] The battery management system (BMS) is used to monitor and manage the power battery pack, monitor the battery status, such as voltage, current, temperature, state of charge, etc., and ensure the safe and efficient operation of the battery. The state of charge (SOC) refers to the percentage of the current power of the battery and is one of the important parameters provided by the battery management system to the energy management device 13.

[0062] The connection between the DC converter 12 and the intermediate DC circuit of the traction converter 11 realizes the charging voltage source of the power battery. The connection between the BUCK circuit 111 and the power battery realizes the charging of the power battery. The connection between the energy management device 13 and the battery management system realizes the real-time monitoring of the state of charge of the power battery. The connection between the energy management device 13 and the DC converter 12 realizes the control of the charging voltage.

[0063] The multiple BUCK circuits 111 allow for individual voltage regulation of each group of power batteries to accommodate different battery characteristics. The current sensor and voltage sensor provide real-time current and voltage information so that the controller 114 can make corresponding adjustments. The energy management device 13 determines the target charging voltage based on the battery voltage information and implements the boost operation through the DC converter 12.

[0064] The charging control circuit of multiple groups of parallel power batteries provided by the embodiment of the present application is applied to multiple groups of power batteries, including: a traction inverter 11, a DC converter 12, and an energy management device 13, wherein the traction inverter 11 includes: multiple BUCK circuits 111 and a controller 114; the output end of the DC converter 12 is connected to the intermediate DC circuit of the traction inverter 11, and each BUCK circuit 111 draws power from the intermediate DC circuit of the traction inverter 11 and is connected to each power battery; the battery management system of each power battery is connected to the energy management device 13, and the energy management device 13 is connected to the controller 114; the energy management device 13 is connected to the DC converter 12; the energy management device 13 determines the target charging voltage in real time according to the battery voltage information of each power battery, controls the DC converter 12 to convert to the target charging voltage, and sends the charge state of the power battery to the controller 114; when the target charging voltage is reached, the controller 114 controls the corresponding BUCK circuit 111 to start charging the corresponding power battery. The energy management device 13 collects the battery voltage information of each power battery in real time, determines the target charging voltage of each battery according to the collected battery voltage information, sends a control signal to the DC converter 12 to adjust its output voltage to the target charging voltage, and sends the state of charge (SOC) of the power battery to the controller 114. After reaching the target charging voltage, the controller 114 controls the corresponding BUCK circuit 111 to open and start charging the power battery. The energy management module controls the DC converter 12 to convert to the target charging voltage so that the charging voltage is within a controllable range. After reaching the target charging voltage, the corresponding BUCK circuit 111 is opened to charge the power battery. By adjusting the output voltage of the DC converter 12 in real time, overcharging or over-discharging caused by excessive voltage difference during charging is avoided, ensuring the stability and safety of the charging process, reducing battery aging, and extending the battery life. By accurately controlling the charging process, energy waste is reduced.

[0065] According to the above embodiment, in order to prevent reverse charging between batteries and provide a discharge path, this embodiment provides a charging control circuit for multiple groups of parallel power batteries, further comprising: multiple diodes D1;

[0066] The cathode of each diode D1 is connected to the first end of the intermediate DC circuit, the anode of the diode D1 is connected to the first end of each power battery, and the second end of the intermediate DC circuit is connected to the second end of each power battery.

[0067] The cathode of diode D1 is connected to the first end of the intermediate DC circuit, and the anode is connected to the first end of the power battery, which ensures that the current can only flow from the intermediate DC circuit to the battery and cannot flow in the reverse direction, thereby preventing reverse charging between batteries.

[0068] The use of diode D1 prevents reverse charging between power batteries, protects the batteries, and prolongs the battery life. The unidirectional flow of current ensures the stability and efficiency of the charging process. By preventing reverse charging, the safety risks caused by overcharging or over-discharging of the battery are reduced.

[0069] According to the above embodiment, in order to more accurately monitor and control the charging process of the power battery and ensure the safety and efficiency of charging, this embodiment provides a specific implementation scheme, wherein the traction converter further includes: a plurality of current detection modules 112, a plurality of voltage detection modules 113;

[0070] The current detection module 112 is connected between the positive electrode of each diode D1 and the first end of the power battery; the voltage detection module 113 is connected in parallel between the first end of the power battery and the second end of the power battery; each current detection module 112 and each voltage detection module 113 monitors the current information and voltage information of the corresponding power battery and sends them to the controller 114;

[0071] The controller 114 receives the current information sent by the current detection module 112 and the voltage information sent by the voltage detection module 113 , and adjusts the current and voltage of the BUCK circuit 111 according to the current information and the voltage information.

[0072] The current detection module 112 is used to monitor the current, detect and record the current information of the power battery. The current information of the corresponding power battery is monitored and sent to the controller 114. The voltage detection module 113 is used to monitor the voltage, detect and record the voltage information of the power battery. In this solution, the voltage detection module 113 monitors the voltage information of the corresponding power battery and sends it to the controller 114. After receiving the current and voltage information, the controller 114 adjusts the current and voltage of the BUCK circuit 111 according to this information to ensure that the power battery is charged with appropriate voltage and current. In this solution, the controller 114 controls the opening of the BUCK circuit 111 according to the current and voltage information to realize the charging of the power battery.

[0073] The current detection module 112 refers to a module for monitoring current, which can detect and record the current information of the power battery. In this solution, the current detection module 112 is connected between the positive pole of each diode D1 and the first end of the power battery, which means that the current detection module 112 is located on the path of the current flowing to the power battery. It is usually a current sensor. The voltage detection module 113 is a module for monitoring voltage, which can detect and record the voltage information of the power battery. In this solution, the voltage detection module 113 is connected in parallel between the first end of the power battery and the second end of the power battery, which means that the voltage detection module 113 can monitor the voltage at both ends of the corresponding power battery. It is usually a voltage sensor. The controller 114 adjusts the current and voltage of the BUCK circuit 111 based on this information to achieve precise control of the power battery charging process.

[0074] By monitoring the current information, the controller 114 can understand the current charging state and adjust the output of the BUCK circuit 111 accordingly to meet different charging requirements. By monitoring the voltage information, the controller 114 can ensure that the battery is not overcharged or undercharged, thereby protecting the battery and extending its service life.

[0075] According to the above embodiment, in order to further optimize the charging process of the power battery and improve the stability and efficiency of the system, this embodiment provides a specific implementation scheme, which also includes: a plurality of reactors 115; each BUCK circuit 111 is connected to each power battery through the reactor 115;

[0076] A first end of each reactor 115 is connected to the output end of the BUCK circuit 111 , and a second end of the reactor 115 is connected to a first end of the power battery.

[0077] The reactor 115 is an electromagnetic device used to limit the rate of change of current, reduce current fluctuations and noise, thereby protecting the circuit and improving the quality of power supply. In this solution, the reactor 115 is used to connect the BUCK circuit 111 and the power battery.

[0078] The reactor 115 limits the rate of change of the current, reduces the current fluctuation, and helps to protect the battery and prolong its service life. By reducing the current fluctuation, the power battery can be charged more smoothly, and the charging efficiency is improved. It helps to stabilize the entire charging system and reduce the system instability caused by current fluctuation. It helps to improve the quality of the power supply, reduce noise and interference, and improve the reliability of the entire system.

[0079] According to the above embodiment, in order to achieve accurate regulation of the current and voltage of the BUCK circuit 111. This embodiment provides a specific implementation scheme, which also includes: an IGBT control module;

[0080] The controller 114 is connected to the IGBT control module and outputs a PWM control signal to the IGBT control module to control the on-time. The IGBT control module is connected to the BUCK circuit and adjusts the current and voltage of the BUCK circuit 111 .

[0081] Insulate-Gate Bipolar Transistor (IGBT) is a power electronic device widely used in switching applications that control high voltage and high current. The IGBT control module refers to a module used to control the switching state of the IGBT. It outputs a pulse width modulation (PWM) signal by receiving instructions from the controller 114, thereby controlling the switch of the BUCK circuit 111 to achieve current and voltage regulation.

[0082] The duty cycle of the PWM control signal (ie, the ratio of the time when the signal is at a high level to the cycle time) can be adjusted, thereby adjusting the output current and voltage of the BUCK circuit 111.

[0083] The controller 114 controls the charging process according to the information from the current detection module 112 and the voltage detection module 113 .

[0084] Figure 2 A circuit diagram of an IGBT control module provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, IGBT is used for PWM control, and the voltage and current are regulated by controlling the switching time.

[0085] The IGBT control module outputs a PWM signal to the BUCK circuit 111 according to the instruction of the controller 114 to adjust the switching time of the BUCK circuit 111 .

[0086] By precisely controlling the switching time of the BUCK circuit 111 , the charging current and voltage can be controlled more precisely.

[0087] According to the above embodiment, in order to achieve accurate regulation of the current and voltage of the BUCK circuit 111. This embodiment provides a specific implementation scheme, which also includes: a display device;

[0088] The display device is connected to the energy management device 13, receives the charging indication status, floating charge indication status, and power supply indication status sent by the energy management device 13, and displays corresponding status icons.

[0089] The energy management device monitors the charging status of the battery in real time, including whether it is currently in the charging state, floating charge state or power supply state. The monitored charging indication status, floating charge indication status, power supply indication status and other information are sent to the display device. After receiving the status information sent by the energy management device, the display device displays the corresponding status icon through the graphical user interface (GUI), so that the user can intuitively understand the current status of the battery. The user can quickly understand the charging status of the battery, improving the user experience.

[0090] The present application also provides a charging control method for multiple groups of parallel power batteries, which is applied to a charging control circuit for multiple groups of parallel power batteries, including: a traction converter 11, a DC converter 12, and an energy management device 13, wherein the traction converter 11 includes: multiple BUCK circuits 111 and a controller 114; the output end of the DC converter 12 is connected to the intermediate DC circuit of the traction converter 11, and each BUCK circuit 111 draws power from the intermediate DC circuit of the traction converter 11 and is connected to each power battery; the battery management system of each power battery is connected to the energy management device 13, and the energy management device 13 is connected to the controller 114; the energy management device 13 is connected to the DC converter 12; Figure 3 As shown, the method includes:

[0091] S11: receiving the state of charge sent by the energy management device in real time;

[0092] S12: When the target charging voltage is reached, the corresponding BUCK circuit is controlled to be turned on to charge the corresponding power battery until the state of charge reaches a preset threshold; wherein the energy management device determines the target charging voltage based on the battery voltage information of each power battery and then controls the DC converter to convert to reach the target charging voltage.

[0093] Step S11 receives the state of charge sent by the energy management device in real time. The state of charge (SOC) is a key parameter provided by the battery management system. In this step, the controller 114 receives the SOC information sent by the energy management device 13 in real time to understand the current state of charge of the battery.

[0094] Step S12: When the target charging voltage is reached, the corresponding BUCK circuit is controlled to be turned on to charge the corresponding power battery until the state of charge reaches the preset threshold. In this step, when the output voltage of the DC converter 12 reaches the target charging voltage, the controller 114 controls the corresponding BUCK circuit 111 to be turned on to start charging the corresponding power battery. The charging process continues until the SOC of the battery reaches the preset threshold, at which time the charging process stops.

[0095] The charging control method for multiple groups of parallel power batteries provided in the present application receives the state of charge sent by the energy management device in real time; when the target charging voltage is reached, the corresponding BUCK circuit is controlled to be turned on to charge the corresponding power battery until the state of charge reaches the preset threshold; wherein, the energy management device determines the target charging voltage according to the battery voltage information of each power battery and then controls the DC converter to convert to the target charging voltage. The energy management module controls the DC converter 12 to convert to the target charging voltage so that the charging voltage is within a controllable range. After reaching the target charging voltage, the corresponding BUCK circuit 111 is turned on to charge the power battery. By real-time monitoring of the battery voltage information and adjusting the output voltage of the DC converter 12, overcharging or over-discharging caused by excessive voltage difference during charging is avoided, the stability and safety of the charging process are ensured, the battery aging is reduced, and the battery service life is extended. By precisely controlling the charging process, energy waste is reduced.

[0096] According to the above embodiment, in order to achieve more accurate charging control, this embodiment provides a specific implementation scheme, which also includes:

[0097] Receive current information sent by the current detection module and voltage information sent by the voltage detection module;

[0098] Determine whether the current information and voltage information meet the preset charging conditions of the current power battery;

[0099] If not, the current and voltage of the BUCK circuit are adjusted according to the current information and the voltage information.

[0100] In this embodiment, the current information sent by the current detection module and the voltage information sent by the voltage detection module are received to determine whether the current information and the voltage information meet the preset charging conditions of the current power battery; the preset charging conditions are usually set based on factors such as battery type, battery status (such as temperature, SOC), and historical charging data to ensure that the charging process is both safe and efficient. In this step, the controller 114 evaluates whether the received current and voltage data meet these preset conditions.

[0101] If not, the current and voltage of the BUCK circuit are adjusted according to the current information and the voltage information. The BUCK circuit is used to adjust the charging voltage and current to meet specific charging requirements. The controller 114 will adjust the settings of the BUCK circuit 111 to change the output of current and voltage to meet the charging conditions.

[0102] By precisely controlling the charging voltage and current, the charging efficiency can be improved and energy loss can be reduced. By avoiding overcharging and undercharging, the service life of the power battery can be extended, and the safety risks caused by improper charging can be reduced.

[0103] According to the above embodiment, this embodiment provides a specific implementation scheme, which also includes:

[0104] Real-time monitoring of whether the state of charge reaches the preset threshold;

[0105] If yes, the BUCK circuit is controlled to switch to floating charge state;

[0106] The charging current of the BUCK circuit is controlled to be reduced to a preset minimum threshold.

[0107] Real-time monitoring of whether the state of charge reaches a preset threshold value. The preset threshold value is to protect the battery and improve the charging efficiency. When the SOC reaches this value, the charging method needs to be adjusted. If so, the BUCK circuit 111 is controlled to switch to a floating charge state. The floating charge state refers to a charging state in which the battery is maintained at a higher voltage level, but the current is very small, which is used to maintain the battery power and prevent the power from decreasing due to self-discharge.

[0108] When the SOC reaches a preset threshold, the controller 114 issues an instruction to switch the BUCK circuit 111 to a floating charge state to maintain the battery power without overcharging. The controller 114 controls the charging current of the BUCK circuit 111 to be reduced to a preset minimum threshold to maintain the battery power and reduce energy loss.

[0109] Through the battery management system, the SOC of the power battery is monitored in real time. When the SOC reaches the preset threshold, the controller 114 adjusts the working state of the BUCK circuit 111 and switches to the floating charge state. In the floating charge state, the battery is maintained at a higher voltage level, but the current is very small to prevent the power from decreasing. In the floating charge state, the charging current is very small, which can reduce energy loss and improve charging efficiency.

[0110] According to the above embodiment, in order to achieve efficient, safe and reliable charging control. This embodiment provides a specific implementation scheme, the energy management device determines the target charging voltage according to the battery voltage information of each power battery and then controls the DC converter to convert to reach the target charging voltage, including:

[0111] Receive battery voltage information sent by the battery management system of each power battery;

[0112] Obtaining a target charging voltage according to the battery voltage information and a preset charging voltage difference;

[0113] The DC converter is controlled to convert according to the target charging voltage until the target charging voltage is reached.

[0114] Receive the battery voltage information v sent by the battery management system of each power battery, and obtain the target charging voltage (v+△d) based on the battery voltage information and the preset charging voltage difference. The preset charging voltage difference refers to the voltage increment preset to achieve the best charging effect, which is used to adjust the charging voltage to meet the actual needs of the battery. The preset charging voltage difference can be adjusted according to actual needs.

[0115] The target charging voltage is calculated based on the current battery voltage and the preset voltage difference, and the DC converter 12 is controlled to convert according to the target charging voltage until the target charging voltage is reached. The operating parameters of the DC converter 12 are adjusted to output the required voltage. The energy management device 13 sends a control signal to the DC converter 12 to gradually adjust its output voltage until the target charging voltage is reached.

[0116] Appropriate charging voltage can improve charging efficiency and reduce energy loss. By accurately controlling the charging voltage, safety risks caused by improper voltage can be reduced.

[0117] According to the above embodiment, in order to achieve accurate control of the charging process, this embodiment provides a specific implementation scheme, which adjusts the current and voltage of the BUCK circuit according to the current information and the voltage information, including:

[0118] Generate a PWM control signal for adjusting the voltage and current according to the current information and the voltage information;

[0119] The on-time of the IGBT control module is controlled according to the PWM control signal to adjust the current and voltage of the BUCK circuit.

[0120] The duty cycle of the PWM control signal is adjustable and is used to control the on and off time of power electronic devices such as IGBT (insulated gate bipolar transistor), thereby adjusting the current and voltage.

[0121] The on-time refers to the length of time that the IGBT is turned on, and its proportion in the PWM cycle determines the magnitude of the current. In this step, the on-time of the IGBT is adjusted according to the duty cycle of the PWM control signal, thereby controlling the output voltage and current of the BUCK circuit.

[0122] Finally, the present application provides a train, comprising a charging control circuit for the above-mentioned multiple groups of parallel power batteries.

[0123] The energy management device 13 collects the battery voltage information of each power battery in real time, determines the target charging voltage of each battery according to the collected battery voltage information, sends a control signal to the DC converter 12 to adjust its output voltage to the target charging voltage, and sends the state of charge (SOC) of the power battery to the controller 114. After reaching the target charging voltage, the controller 114 controls the corresponding BUCK circuit 111 to open and start charging the power battery. The energy management module controls the DC converter 12 to convert to the target charging voltage so that the charging voltage is within a controllable range. After reaching the target charging voltage, the corresponding BUCK circuit 111 is opened to charge the power battery. By adjusting the output voltage of the DC converter 12 in real time, overcharging or over-discharging caused by excessive voltage difference during charging is avoided, ensuring the stability and safety of the charging process, reducing battery aging, and extending the battery life. By accurately controlling the charging process, energy waste is reduced.

[0124] The above is a detailed introduction to the charging control circuit and method of multiple groups of parallel power batteries provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0125] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A charging control circuit for multiple groups of parallel power batteries, characterized in that: Applied to multiple groups of power batteries, including: a traction converter, a DC converter, and an energy management device, wherein the traction converter includes: multiple BUCK circuits and a controller; The output end of the DC converter is connected to the intermediate DC circuit of the traction converter, and each of the BUCK circuits draws power from the intermediate DC circuit of the traction converter and is connected to each of the power batteries; The battery management system of each power battery is connected to the energy management device, and the energy management device is connected to the controller; the energy management device is connected to the DC converter; The energy management device determines the target charging voltage in real time according to the battery voltage information of each power battery, controls the DC converter to convert to the target charging voltage, and sends the charge state of the power battery to the controller; when the target charging voltage is reached, the controller controls the corresponding BUCK circuit to start charging the corresponding power battery.

2. The charging control circuit for multiple groups of parallel power batteries according to claim 1, characterized in that: Also includes: Multiple diodes; The cathode of each diode is connected to the first end of the intermediate DC circuit, the anode of each diode is connected to the first end of each power battery, and the second end of the intermediate DC circuit is connected to the second end of each power battery.

3. The charging control circuit for multiple groups of parallel power batteries according to claim 2, characterized in that: The traction converter further includes: a plurality of current detection modules and a plurality of voltage detection modules; The current detection module is connected between the positive electrode of each diode and the first end of the power battery; the voltage detection module is connected in parallel between the first end of the power battery and the second end of the power battery; each current detection module and each voltage detection module monitor the current information and voltage information of the corresponding power battery and send them to the controller; The controller receives the current information sent by the current detection module and the voltage information sent by the voltage detection module, and adjusts the current and voltage of the BUCK circuit according to the current information and the voltage information.

4. The charging control circuit for multiple groups of parallel power batteries according to claim 3, characterized in that: Also includes: Multiple reactors; Each of the BUCK circuits is connected to each of the power batteries via the reactor; The first end of each of the reactors is connected to the output end of the BUCK circuit, and the second end of the reactor is connected to the first end of the power battery.

5. The charging control circuit for multiple groups of parallel power batteries according to claim 3, characterized in that: Also includes: IGBT control module; The controller is connected to the IGBT control module and outputs a PWM control signal to the IGBT control module to control the on-time. The IGBT control module is connected to the BUCK circuit and adjusts the current and voltage of the BUCK circuit.

6. The charging control circuit for multiple groups of parallel power batteries according to claim 1, characterized in that: Also includes: Display device; The display device is connected to the energy management device, receives the charging indication status, floating charge indication status, and power supply indication status sent by the energy management device, and displays corresponding status icons.

7. A charging control method for multiple groups of parallel power batteries, characterized in that: A charging control circuit applied to multiple groups of parallel power batteries comprises: a traction converter, a DC converter, and an energy management device, wherein the traction converter comprises: a plurality of BUCK circuits and a controller; the output end of the DC converter is connected to the intermediate DC circuit of the traction converter, each of the BUCK circuits takes power from the intermediate DC circuit of the traction converter and is connected to each of the power batteries; the battery management system of each of the power batteries is connected to the energy management device, and the energy management device is connected to the controller; the energy management device is connected to the DC converter; the method comprises: receiving the state of charge sent by the energy management device in real time; When the target charging voltage is reached, the corresponding BUCK circuit is controlled to be turned on to charge the corresponding power battery until the state of charge reaches a preset threshold; wherein the energy management device determines the target charging voltage based on the battery voltage information of each power battery and then controls the DC converter to convert to reach the target charging voltage.

8. The charging control method for multiple groups of parallel power batteries according to claim 7, characterized in that: Also includes: Receive current information sent by the current detection module and voltage information sent by the voltage detection module; Determining whether the current information and the voltage information meet the preset charging conditions of the current power battery; If not, the current and voltage of the BUCK circuit are adjusted according to the current information and the voltage information.

9. The charging control method for multiple groups of parallel power batteries according to claim 8, characterized in that: Also includes: Real-time monitoring of whether the state of charge reaches a preset threshold; If yes, control the BUCK circuit to switch to a floating charge state; The charging current of the BUCK circuit is controlled to decrease to a preset minimum threshold.

10. The charging control method for multiple groups of parallel power batteries according to claim 8, characterized in that: The energy management device determines the target charging voltage according to the battery voltage information of each power battery and then controls the DC converter to convert the target charging voltage, including: Receiving battery voltage information sent by the battery management system of each of the power batteries; Obtaining a target charging voltage according to the battery voltage information and a preset charging voltage difference; The DC converter is controlled to convert according to the target charging voltage until the target charging voltage is reached.

11. The charging control method for multiple groups of parallel power batteries according to claim 8, characterized in that: The step of adjusting the current and voltage of the BUCK circuit according to the current information and the voltage information includes: Generate a PWM control signal for adjusting the voltage and current according to the current information and the voltage information; The on-time of the IGBT control module is controlled according to the PWM control signal to adjust the current and voltage of the BUCK circuit.

12. A train, characterized in that: A charging control circuit comprising a plurality of groups of parallel-connected power batteries as described in any one of claims 1 to 6.

Images