Modularized battery management system

Abstract

The application provides a modular battery management system, comprising: a battery DC interface for connecting a battery terminal; the voltage and temperature sampling equalization module is used for sampling the voltage and the temperature of the single battery; the BMS battery processing module is used for receiving the voltage and temperature signals of the single batteries from the voltage and temperature sampling equalization module and carrying out equalization protection on the batteries; the sampling and over-current protection module is used for sampling the total voltage and current of the module battery and executing over-voltage, under-voltage and over-current protection functions of the battery module; the DC-DC buck-boost module is used for executing charging and discharging bidirectional DC power conversion; the soft start and reverse connection protection module is used for performing reverse connection protection when the DC output is connected with an external power supply; and the DC output / input interface is used for being connected with an energy storage power supply or a DC power supply for discharging and charging. The BMS control module is used for controlling calculation of SOC and SOH and controlling operation logic; and the function key module is used for confirming the battery type of the battery DC interface.

Description

Technical Field

[0001] The present invention relates to the field of modular battery technology, and in particular to a modular battery management system. Background Art

[0002] The battery management system (BMS) is an important component of the energy storage system. In the current detection management methods, the detection management of BMS mainly includes two methods. The first is to connect the energy storage battery system to the BMS for detection; the second is to use dedicated detection equipment for detection. The first detection method requires waiting for the energy storage battery system to be integrated, which is likely to cause dependence and lag in BMS system detection; the second detection method uses a dedicated detection equipment with a higher cost.

[0003] Currently, modular battery BMS is used, which has relatively simple functions and can detect and calculate the voltage, temperature, battery balancing, etc. of the battery cell. However, the current BMS output voltage can only be the fixed voltage of the battery itself. It cannot be selected for high-voltage energy storage inverters, low-voltage energy storage inverters, high-voltage power supplies and low-voltage power supplies, which limits the use of modular battery BMS. Summary of the invention

[0004] The present application provides a modular battery management system, which integrates DC-DC bidirectional buck-boost output / input functions, and can convert 48V or 51.2V batteries into wide voltage output (DC58V-300V). The system can automatically identify the battery 48V voltage or 51.2V voltage, and convert the battery DC voltage into the corresponding DC high-voltage output. At the same time, it can also reversely manage the battery charging and can independently determine the charging and discharging.

[0005] In view of this, the present application provides a modular battery management system, which includes: a battery DC interface for connecting battery terminals; a voltage and temperature sampling and balancing module, connected to the battery DC interface, for sampling the voltage and temperature of the single battery, and transmitting them to the battery management system BMS battery processing module; the BMS battery processing module, connected to the voltage and temperature sampling and balancing module, for receiving the voltage and temperature signals of the single battery from the voltage and temperature sampling and balancing module, and performing balancing and protection functions on the battery; a sampling and overcurrent protection module, connected to the battery DC interface, for sampling the overall voltage and current of the module battery, and performing overvoltage, undervoltage and overcurrent protection functions on the battery module; a DC-DC buck-boost module, connected to the sampling and overcurrent protection module, for performing a charging and discharging bidirectional DC power conversion function on the battery pack, which can be used for charging or discharging functions; a soft start and reverse connection protection module, connected to the DC-DC buck-boost module, for playing a reverse role when the DC output is connected to an external power supply. connection protection function; a DC output / input interface connected to the soft start and reverse connection protection module, used to connect an energy storage power supply or a DC power supply for discharging and charging; a BMS control module, respectively connected to the sampling and overcurrent protection module, the DC-DC buck-boost module, the soft start and reverse connection protection module, and the BMS battery processing module, used to control the calculation of the battery state of charge SOC and the battery state of health SOH, and control the operation logic; a function key module, connected to the BMS control module, used to confirm the battery type of the battery DC interface; a communication module, connected to the BMS control module, used to communicate with the outside; a display module, connected to the BMS control module, used to display the real-time working status of the battery; the soft start and reverse connection protection module is specifically used to first use a small current to fill the capacitor when the energy storage power supply or the external DC power supply has a peak current, and then use a large current DC output to protect the energy storage power supply or the external DC power supply connected to the DC output / input interface.

[0006] Optionally, in a possible implementation, the battery DC interface is specifically used to connect a 48V battery module, or a 51.2V battery module; wherein the rated voltage of the 48V battery module is 48V, corresponding to 15 strings of lithium iron phosphate, and the voltage range is 42V-54.75V; the rated voltage of the 51.2V battery is 51.2V, corresponding to 16 strings of lithium iron phosphate, and the voltage range is 44.8V-58.4V.

[0007] Optionally, in a possible implementation, when the DC-DC buck-boost module is discharging, it is boosted by a BOOST circuit and discharged at a fixed frequency and duty cycle; when the DC-DC buck-boost module is charging, it is bucked by a BUCK circuit and charged at a fixed frequency and duty cycle.

[0008] Optionally, in a possible implementation, the BMS control module is also used to control the DC-DC buck-boost module, control the soft start and reverse connection protection module, control the sampling and overcurrent protection module, control the function button module, the communication module and the display module.

[0009] Optionally, in a possible implementation, the function button module adopts a digital mode setting, wherein button No. 1 is used to identify a 48V battery, and button No. 2 is used to identify a 51.2V battery.

[0010] Optionally, in a possible implementation, when the button No. 1 is pressed and held for 3 seconds, the BMS control module recognizes that the battery DC interface is connected to a 48V battery, enters a 48V battery mode, and manages the charge and discharge of the 48V battery; when the button No. 1 is pressed and held for 3 seconds again, the 48V battery mode is exited; when the button No. 2 is pressed and held for 3 seconds, the BMS control module recognizes that the battery DC interface is connected to a 51.2V battery, enters a 51.2V battery mode, and manages the charge and discharge of the 51.2V battery; when the button No. 2 is pressed and held for 3 seconds again, the 48V battery mode is exited.

[0011] Optionally, in a possible implementation, the voltage range of the DC output / input interface is 58V-300V. When the No. 3 button in the function button module is pressed for 3 seconds, the BMS control module recognizes that it enters the DC58V output / input control mode, controls the charge and discharge management of DC-DC58V, DC58V constant voltage discharge output, or DC58V constant voltage charging input. When the No. 3 button is pressed for 3 seconds again, the DC58V output / input control mode is exited; when the No. 4 button in the function button module is pressed for 3 seconds, the BMS control module recognizes that it enters the DC58V output / input control mode. C100V output / input control mode, control charging and discharging management of DC-DC100V, DC100V constant voltage discharge output, or DC100V constant voltage charge input. When the No. 4 button is pressed for 3 seconds again, the DC100V output / input control mode is exited; when the No. 5 button in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC150V output / input control mode, controls charging and discharging management of DC-DC150V, DC150V constant voltage discharge output, or DC150V constant voltage charge input. When the No. 5 button is pressed for 3 seconds again, the BMS control module recognizes and enters the DC150V output / input control mode. , exit the DC150V output / input control mode; when the No. 6 button in the function button module is pressed for 3 seconds, the BMS control module recognizes that it has entered the DC200V output / input control mode, and controls the charge and discharge management of DC-DC200V, DC200V constant voltage discharge output, or DC200V constant voltage charging input. When the No. 6 button is pressed for 3 seconds again, the DC200V output / input control mode is exited; when the No. 7 button in the function button module is pressed for 3 seconds, the BMS control module recognizes that it has entered the DC25 ... DC250V controls charge and discharge management, DC250V constant voltage discharge output, or DC250V constant voltage charging input. When the No. 7 button is pressed for 3 seconds again, the DC250V output / input control mode is exited; when the No. 8 button in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC300V output / input control mode, and controls the charge and discharge management of DC-DC300V, DC300V constant voltage discharge output, or DC300V constant voltage charging input. When the No. 8 button is pressed for 3 seconds again, the DC300V output / input control mode is exited.

[0012] Optionally, in a possible implementation, the communication module includes: at least one of: a DO / DI communication interface, a parallel communication interface, an RS485 communication interface, a CAN communication interface, and a BMS power supply communication interface.

[0013] The present application provides a modular battery management system, which includes a battery DC interface for connecting battery terminals; a voltage and temperature sampling and balancing module, connected to the battery DC interface, for sampling the voltage and temperature of a single cell and transmitting them to a battery management system BMS battery processing module; a BMS battery processing module, connected to the voltage and temperature sampling and balancing module, for receiving the voltage and temperature signals of the single cell from the voltage and temperature sampling and balancing module, and performing balancing and protection functions on the battery; a sampling and overcurrent protection module, connected to the battery DC interface, for sampling the overall voltage and current of the module battery, and performing overvoltage, undervoltage and overcurrent protection functions on the battery module; a DC-DC buck-boost module, connected to the sampling and overcurrent protection module, for performing a charging and discharging bidirectional DC power conversion function on a battery pack, and can be used for charging or discharging voltage conversion; a soft start and reverse connection protection module, connected to the DC-DC buck-boost module, for performing a reverse connection protection function when the DC output is connected to an external power supply; a DC output / input interface, connected to the soft start and reverse connection protection module, for connecting an energy storage power supply or a DC power supply for discharging and charging. The BMS control module is respectively connected to the sampling and overcurrent protection module, the DC-DC buck-boost module, the soft start and reverse connection protection module, and the BMS battery processing module, and is used to control the calculation of the battery state of charge SOC and the battery state of health SOH, and control the operation logic; the function key module is connected to the BMS control module, and is used to confirm the battery type of the battery DC interface; the communication module is connected to the BMS control module and is used for external communication; the display module is connected to the BMS control module and is used to display the real-time working status of the battery; the soft start and reverse connection protection module is specifically used to first use a small current to fill the capacitor when the energy storage power supply or external DC power supply has a peak current instantaneously, and then use a large current DC output to protect the energy storage power supply or external DC power supply connected to the DC output / input interface.

[0014] The system integrates the DC-DC bidirectional buck-boost output / input function, which can convert 48V or 51.2V batteries into high voltage output (DC58V-300V). The system can automatically identify the battery voltage of 48V or 51.2V, convert the battery DC voltage into the corresponding DC high voltage output, and can also charge the battery in reverse, and can independently determine the charge and discharge. It is also compatible with the DC positive and negative pole reverse connection protection function and the DC output soft start function, which can well protect the safety of the energy storage power supply and the external DC power supply connection. At the same time, it also solves the problem that the BMS output voltage can only be the fixed voltage of the battery itself. Different output voltages can be set arbitrarily according to the input voltage of different power supplies. It can adapt to high and low voltage power supplies on the market, including energy storage inverters and DC power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a modular battery management system provided in an embodiment of the present application; Figure 2a A further schematic diagram of a communication module in a modular battery management system provided in an embodiment of the present application; Figure 2b A circuit diagram of a DC-DC buck-boost module in a modular battery management system provided in an embodiment of the present application; Figure 2c A pulse width modulation signal waveform diagram of a switch MOS tube provided in an embodiment of the present application; Figure 3 A single-machine wiring diagram of a modular battery management system provided in an embodiment of the present application; Figure 4 A modular battery management system multi-machine parallel wiring diagram provided in an embodiment of the present application; Figure 5 A modular battery management system multi-machine parallel wiring diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] 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 those skilled in the art without creative work are within the scope of protection of this application.

[0017] The term "and / or" in this application can be a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0018] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or modules is not necessarily limited to those steps or modules that are clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products or devices.

[0019] The battery management system BMS is an important component of the energy storage system. Among the current detection methods, there are two main ways to detect the BMS system. The first is to connect the energy storage battery system to the BMS for detection; the second is to use dedicated detection equipment for detection. The first detection method requires waiting for the energy storage battery system to be fully integrated, which is likely to cause dependence and lag in the detection of the BMS system; the second detection method uses a dedicated detection equipment with a higher cost.

[0020] Currently, modular battery BMS is used, which has relatively simple functions and can detect and calculate the voltage, temperature, battery balancing, etc. of the battery cell. However, the current BMS output voltage can only be the fixed voltage of the battery itself. It cannot be selected for high-voltage energy storage inverters, low-voltage energy storage inverters, high-voltage power supplies and low-voltage power supplies, which limits the use of modular battery BMS.

[0021] At the same time, the current BMS parallel function of this module is relatively simple. Although it has a parallel function, it is only a rigid parallel function. The battery module voltages are different, the battery circulation current is large, the loss is large, the battery cell consistency is poor, and the battery life is reduced.

[0022] In order to solve the above problems, the present application provides a modular battery management system, which integrates a DC-DC bidirectional buck-boost output / input function, and can convert a 48V or 51.2V battery into a high voltage output (DC58V-300V). The system can automatically identify the battery's 48V voltage or 51.2V voltage, and convert the battery DC voltage into the corresponding DC high voltage output. At the same time, it can also charge the battery in reverse, and can independently determine the charge and discharge. It is also compatible with the DC positive and negative pole reverse connection protection function and the DC output soft start function, which can well protect the safety of the connection between the energy storage power supply and the external DC power supply. At the same time, it also solves the problem that the BMS output voltage can only be the fixed voltage of the battery itself. Different output voltages can be set arbitrarily according to the input voltage of different power supplies, and can adapt to high and low voltage power supplies on the market, including energy storage inverters and DC power supplies.

[0023] Moreover, the system can also realize parallel connection of multiple modular battery management systems through the CAN bus, thereby expanding the capacity and power, and can support 16 parallel machines. At the same time, it also solves the problem of circulating current in parallel connection of multiple machines in the past. When paralleling, the same output voltage can be set, which can eliminate the influence of circulating current and greatly improve the output efficiency. The maximum efficiency of discharge operation exceeds 97%, and the maximum efficiency of charging operation exceeds 98%. At the same time, the consistency of the battery has been greatly improved, extending the battery life.

[0024] See also Figure 1, a modular battery management system provided in this application specifically includes: Battery DC interface, used to connect battery terminals.

[0025] The voltage and temperature sampling and balancing module is connected to the battery DC interface and is used to sample the voltage and temperature of the single battery and transmit them to the battery management system BMS battery processing module.

[0026] The BMS battery processing module is connected to the voltage and temperature sampling and balancing module, and is used to receive the voltage and temperature signals of the single cells from the voltage and temperature sampling and balancing module, and perform balancing and protection functions on the cells.

[0027] The sampling and overcurrent protection module is connected to the battery DC interface and is used to sample the overall voltage and current of the module battery and perform overvoltage, undervoltage and overcurrent protection functions of the battery module.

[0028] The DC-DC step-up / down module is connected to the sampling and overcurrent protection module and is used to perform a bidirectional DC power conversion function for charging and discharging the battery pack, and can be used for charging or discharging voltage conversion.

[0029] The soft start and reverse connection protection module is connected to the DC-DC buck-boost module and is used for reverse connection protection when the DC output is connected to an external power supply.

[0030] The DC output / input interface is connected to the soft start and reverse connection protection module, and is used to connect the energy storage power supply or DC power supply for discharging and charging. The BMS control module is respectively connected to the sampling and overcurrent protection module, the DC-DC buck-boost module, the soft start and reverse connection protection module, and the BMS battery processing module, and is used to control the calculation of the battery state of charge SOC and the battery health state SOH, and control the operation logic.

[0031] The function button module is connected to the BMS control module and is used to confirm the battery type of the battery DC interface.

[0032] The communication module is connected to the BMS control module and is used for communicating with the outside.

[0033] The display module is connected to the BMS control module and is used to display the real-time working status of the battery.

[0034] Specifically, the battery DC interface is specifically used to connect a 48V battery module or a 51.2V battery module; wherein the rated voltage of the 48V battery module is 48V, corresponding to 15 strings of lithium iron phosphate, and the voltage range is 42V-54.75V; the rated voltage of the 51.2V battery is 51.2V, corresponding to 16 strings of lithium iron phosphate, and the voltage range is 44.8V-58.4V.

[0035] Furthermore, when the DC-DC buck-boost module is discharging, the voltage is boosted by the BOOST circuit and discharged at a fixed frequency and duty cycle; when the DC-DC buck-boost module is charging, the voltage is stepped down by the BUCK circuit and charged at a fixed frequency and duty cycle.

[0036] In one implementation, the soft start and reverse connection protection module is used to protect the corresponding connected energy storage power supply or external DC power supply from being burned out when the positive and negative poles of the DC output / input interface and the energy storage power supply or external DC power supply are reversely connected.

[0037] Specifically, the soft start and reverse connection protection module is specifically used to first use a small current to fill the capacitor, and then use a large current DC output to protect the energy storage power supply or external DC power supply connected to the DC output / input interface when there is a peak current of a large current when the energy storage power supply or external DC power supply is connected.

[0038] Specifically, the BMS control module is also used to control the DC-DC buck-boost module, control the soft start and reverse connection protection module, control the sampling and overcurrent protection module, control the function button module, the communication module and the display module.

[0039] In a possible implementation, the function button module is set in a digital mode, wherein button No. 1 is used to identify a 48V battery, and button No. 2 is used to identify a 51.2V battery.

[0040] Specifically, when the No. 1 button is pressed for 3 seconds, the BMS control module recognizes that the battery DC interface is connected to a 48V battery, enters the 48V battery mode, and manages the charge and discharge of the 48V battery. When the No. 1 button is pressed for 3 seconds again, the 48V battery mode is exited. When the No. 2 button is pressed for 3 seconds, the BMS control module recognizes that the battery DC interface is connected to a 51.2V battery, enters the 51.2V battery mode, and manages the charge and discharge of the 51.2V battery. When the No. 2 button is pressed for 3 seconds again, the 48V battery mode is exited.

[0041] The voltage output of the DC output / input interface ranges from 58V to 300V. When button No. 3 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC58V output / input control mode, controls the charging and discharging management of DC-DC58V, DC58V constant voltage discharge output, or DC58V constant voltage charging input. When button No. 3 is pressed for 3 seconds again, the DC58V output / input control mode is exited.

[0042] It should be noted that charging input and discharging output are not performed at the same time, and the charging and discharging control programs are separate, but they can be set in the same mode, where the DC output / input interface has the function of identifying discharge and charging. When discharging, the power supply connected to the DC output / input interface has no voltage, and when charging, the power supply connected to the DC output / input interface has voltage. Discharging and charging are determined by identifying whether the interface has voltage, thereby selecting the charging and discharging control programs.

[0043] When button No. 4 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC100V output / input control mode, controls the charging and discharging management of DC-DC100V, DC100V constant voltage discharge output, or DC100V constant voltage charging input. When button No. 4 is pressed for 3 seconds again, the DC100V output / input control mode is exited.

[0044] When button No. 5 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC150V output / input control mode, controls the charging and discharging management of DC-DC150V, DC150V constant voltage discharge output, or DC150V constant voltage charging input. When button No. 5 is pressed for 3 seconds again, the DC150V output / input control mode is exited.

[0045] When button No. 6 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC200V output / input control mode, controls the charging and discharging management of DC-DC200V, DC200V constant voltage discharge output, or DC200V constant voltage charging input. When button No. 6 is pressed for 3 seconds again, the DC200V output / input control mode is exited.

[0046] When button No. 7 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC250V output / input control mode, controls the charging and discharging management of DC-DC250V, DC250V constant voltage discharge output, or DC250V constant voltage charging input. When button No. 7 is pressed for 3 seconds again, the DC250V output / input control mode is exited.

[0047] When button No. 8 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC300V output / input control mode, controls the charging and discharging management of DC-DC300V, DC300V constant voltage discharge output, or DC300V constant voltage charging input. When button No. 8 is pressed for 3 seconds again, the DC300V output / input control mode is exited.

[0048] See also Figure 2aThe communication module includes at least one of the following: DO / DI communication interface, parallel communication interface, RS485 communication interface, CAN communication interface, and BMS power communication interface. The parallel communication interface is responsible for the communication between the parallel battery module systems. Normally, the first one to be powered on is the master, followed by the slave, to ensure the stability of the parallel output voltage.

[0049] See also Figure 2b The DC-DC buck-boost module is composed of an inductor L1, a switch MOS tube Q1, a switch MOS tube Q2, a capacitor C2, and a load RL.

[0050] This DC-DC buck-boost module can be used for boosting. When the BMS is connected to a 48V battery, it can be boosted through the DC-DC bidirectional buck-boost circuit to output different voltages such as 58V, 100V, 150V, 200V, 250V, and 300V. Since the inductor L1, the switch MOS tube Q1, the switch MOS tube Q2, and the capacitor C2 form a BOOST boost circuit, in the BOOST boost mode, when the switch MOS tube Q1 is turned on, the MOS tube Q2 is turned off, and the inductor L1 stores energy. When the switch MOS tube Q1 is turned off, the MOS tube Q2 is turned on, the inductor releases energy, and the voltage across the inductor is superimposed on the input voltage 48V to form a higher output voltage. The output voltage Uo is the input voltage Ui divided by 1 minus the duty cycle D, that is, Uo=Ui / (1-D).

[0051] Therefore, the output voltage is greater than the input voltage. The output Uo can be controlled by controlling the duty cycle D, where the duty cycle D=Ton / Ts, the signal period is Ts, the signal frequency is f=1 / Ts, the on time is Ton, the off time is Toff, and the period Ts=Ton+Toff. The signal of the switch MOS tube is a PWM (Pulse, width, modulation) pulse width modulation signal. Therefore, as long as the on time and off time of the pulse width modulation signal are controlled by the processor chip (KF32F330KQV), the duty cycle of Q1 can be controlled, and then the output voltage Uo can be controlled by controlling the conduction of MOS tubes Q1 and Q2.

[0052] For example, if the output voltage is 58V, then 58=48 / (1-D), and D=0.172.

[0053] For example, if the output voltage is 100V, then 100=48 / (1-D), and D=0.52.

[0054] For example, if the output voltage is 150V, then 150=48 / (1-D), and D=0.68.

[0055] For example, if the output voltage is 200V, then 200=48 / (1-D), and D=0.76.

[0056] For example, if the output voltage is 250V, then 250=48 / (1-D), and D=0.808.

[0057] For example, if the output voltage is 300V, then 300=48 / (1-D), and D=0.84.

[0058] The boost is achieved in this way. The DC-DC buck-boost module can be used for bucking. When the BMS is connected to a 48V battery, the DC-DC bidirectional buck-boost circuit is used for bucking. U0 can buck different voltages such as 58V, 100V, 150V, 200V, 250V, and 300V to charge the 48V battery. Since the inductor L1, the switch MOS tubes Q1, Q2, and the capacitor C2 form a BUCK buck circuit, in the BUCK mode, when the MOS switch tube Q2 is turned on, the MOS tube Q1 is turned off, and the current flows to the 48V battery through the inductor L1. The current in the inductor will generate self-inductance while linearly increasing, and the self-inductance will hinder the rise of the current. The inductor converts the electrical energy into magnetic energy and stores it. At this time, the direction of the self-inductance potential is positive on the left and negative on the right. At this time, the inductor L1 stores energy. When the MOS switch tube Q2 is turned off, the MOS tube Q1 is turned on, the inductor releases energy, and a loop is formed through Q1 to maintain the output voltage. The output voltage Ui is the input voltage Uo multiplied by the duty cycle D, that is, Ui=Uo*D. Therefore, the output voltage is less than the input voltage. Similarly, the output Uo can be controlled by controlling the duty cycle D, where the duty cycle D=Ton / Ts. Therefore, as long as the on-time and off-time of the pulse width modulation signal are controlled by the processor chip (KF32F330KQV), the duty ratio of Q2 can be controlled, and then the output voltage Ui can be controlled by controlling the conduction of MOS tubes Q1 and Q2.

[0059] If the input voltage is 58V, that is 48=58*D, D=0.827.

[0060] If the input voltage is 100V, that is 48=100*D, D=0.48.

[0061] If the input voltage is 150V, then 48=150*D, and D=0.32.

[0062] For example, if the input voltage is 200V, 48=200*D, D=0.24.

[0063] If the input voltage is 250V, then 48=250*D, and D=0.192.

[0064] For example, if the input voltage is 300V, 48=300*D, D=0.16.

[0065] In this way, the pressure is reduced.

[0066] See also Figure 2c, the present application provides a waveform diagram of pulse width modulation (PWM) of a switching MOS tube.

[0067] See also Figure 3 , this application provides a modular battery management system stand-alone wiring diagram. Figure 4 and Figure 5 , Figure 4 and Figure 5 A parallel wiring diagram of a modular battery management system based on batteries of the same type and a parallel wiring diagram of a modular battery management system based on batteries of different types are provided respectively.

[0068] Due to differences between battery module devices, non-complete line parameters and differences in initial operation, there are certain differences in the output voltage of each battery module, which will cause the battery module output current to flow from high-level battery modules to low-level battery modules, thus forming a current loop.

[0069] The circulating current flows from one battery module to another, and does not flow through the power supply or energy storage power supply. When the circulating current is small, it will not have much impact on the performance of the battery module. If the circulating current is too large, it will cause a short circuit between the battery modules, and distort the waveforms of the voltage and current, reduce the power quality, and reduce the efficiency. The main reason for the circulating current is that the output voltage parameters of the battery modules are not consistent, and the highs and lows are different. In this application, the modular battery management system sets the same voltage and parameters, so that there will be no high-level battery modules flowing to low-level battery modules, and no current circulation will be formed. The problem of parallel circulating current can be avoided.

[0070] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0071] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0072] In the embodiments provided in this application, it should be understood that the disclosed methods can be implemented in other ways without exceeding the spirit and scope of this application. The current embodiment is only an illustrative example and should not be used as a limitation. The specific content given should not limit the purpose of this application. For example, some features can be ignored or not executed.

[0073] The technical means disclosed in the present application are not limited to the technical means disclosed in the above-mentioned implementation methods, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also regarded as the protection scope of this application.

[0074] A modular battery management system provided in the embodiments of the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application; at the same time, for those of ordinary skill in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application. Although the present application is described in detail with reference to the aforementioned embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A modular battery management system, characterized in that: The system comprises: Battery DC interface, used to connect battery terminals; A voltage and temperature sampling and balancing module is connected to the battery DC interface and is used to sample the voltage and temperature of the single battery and transmit them to the battery management system BMS battery processing module; A BMS battery processing module is connected to the voltage and temperature sampling and balancing module, and is used to receive the voltage and temperature signals of the single battery from the voltage and temperature sampling and balancing module, and perform balancing and protection functions on the battery; A sampling and overcurrent protection module, connected to the battery DC interface, for sampling the overall voltage and current of the module battery and performing overvoltage, undervoltage and overcurrent protection functions of the battery module; A DC-DC buck-boost module, connected to the sampling and overcurrent protection module, is used to perform a bidirectional DC power conversion function for charging and discharging the battery pack, and can be used for charging or discharging voltage conversion; A soft start and reverse connection protection module is connected to the DC-DC buck-boost module and is used to provide reverse connection protection when the DC output is connected to an external power supply; DC output / input interface, used to connect energy storage power supply or DC power supply for discharging and charging; A BMS control module, which is respectively connected to the sampling and overcurrent protection module, the DC-DC buck-boost module, the soft start and reverse connection protection module, and the BMS battery processing module, and is used to control the calculation of the battery state of charge SOC and the battery state of health SOH, and control the operation logic; A function button module, connected to the BMS control module, for confirming the battery type of the battery DC interface; A communication module, connected to the BMS control module, for communicating with the outside; A display module, connected to the BMS control module, for displaying the real-time working status of the battery; The soft start and reverse connection protection module is specifically used to first use a small current to fill the capacitor and then use a large current DC output to protect the energy storage power supply or external DC power supply connected to the DC output / input interface when there is a peak large current when the energy storage power supply or external DC power supply is connected.

2. The modular battery management system according to claim 1, characterized in that: The battery DC interface is specifically used to connect a 48V battery module or a 51.2V battery module; Among them, the rated voltage of the 48V battery module is 48V, corresponding to 15 strings of lithium iron phosphate, and the voltage range is 42V-54.75V; The rated voltage of the 51.2V battery is 51.2V, corresponding to 16 strings of lithium iron phosphate, and the voltage range is 44.8V-58.4V.

3. The modular battery management system according to claim 1, characterized in that: When the DC-DC buck-boost module is discharging, the voltage is boosted by the BOOST circuit and the module is discharged at a fixed frequency and duty cycle; When the DC-DC buck-boost module is charging, the voltage is reduced through the BUCK circuit and charged at a fixed frequency and duty cycle.

4. The modular battery management system according to claim 1, characterized in that: The BMS control module is also used to control the DC-DC buck-boost module, control the soft start and reverse connection protection module, control the sampling and overcurrent protection module, control the function key module, the communication module and the display module.

5. The modular battery management system according to claim 1, characterized in that: The function button module is set in a digital mode, wherein button No. 1 is used to identify a 48V battery, and button No. 2 is used to identify a 51.2V battery.

6. The modular battery management system according to claim 5, characterized in that: When the No. 1 button is pressed for 3 seconds, the BMS control module recognizes that the battery DC interface is connected to a 48V battery, enters the 48V battery mode, and manages the charge and discharge of the 48V battery. When the No. 1 button is pressed for 3 seconds again, the 48V battery mode is exited. When the No. 2 button is pressed for 3 seconds, the BMS control module recognizes that the battery DC interface is connected to a 51.2V battery, enters the 51.2V battery mode, and manages the charge and discharge of the 51.2V battery. When the No. 2 button is pressed for 3 seconds again, the 48V battery mode is exited.

7. The modular battery management system according to claim 6, characterized in that: The output voltage of the DC output / input interface is in the range of 58V-300V. When the No. 3 button in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC58V output / input control mode, controls the charge and discharge management of DC-DC58V, DC58V constant voltage discharge output, or DC58V constant voltage charging input. When the No. 3 button is pressed for 3 seconds again, the DC58V output / input control mode is exited; When the No. 4 button in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC100V output / input control mode, controls the charge and discharge management of DC-DC100V, DC100V constant voltage discharge output, or DC100V constant voltage charging input. When the No. 4 button is pressed for 3 seconds again, the DC100V output / input control mode is exited; When the No. 5 button in the function button module is pressed for 3 seconds, the BMS control module recognizes that it enters the DC150V output / input control mode, controls the charge and discharge management of DC-DC150V, DC150V constant voltage discharge output, or DC150V constant voltage charging input. When the No. 5 button is pressed for 3 seconds again, the DC150V output / input control mode is exited; When the No. 6 button in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC200V output / input control mode, controls the charge and discharge management of DC-DC200V, DC200V constant voltage discharge output, or DC200V constant voltage charging input. When the No. 6 button is pressed for 3 seconds again, the DC200V output / input control mode is exited; When the No. 7 button in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC250V output / input control mode, controls the charging and discharging management of DC-DC250V, DC250V constant voltage discharge output, or DC250V constant voltage charging input. When the No. 7 button is pressed for 3 seconds again, the DC250V output / input control mode is exited; When button No. 8 in the function button module is pressed for 3 seconds, the BMS control module recognizes and enters the DC300V output / input control mode, controls the charging and discharging management of DC-DC300V, DC300V constant voltage discharge output, or DC300V constant voltage charging input. When button No. 8 is pressed for 3 seconds again, the DC300V output / input control mode is exited.

8. The modular battery management system according to claim 1, characterized in that: The communication module includes: at least one of a DO / DI communication interface, a parallel communication interface, an RS485 communication interface, a CAN communication interface, and a BMS power supply communication interface.

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