TWI683212B - Lithium ion battery all-round safety monitoring system and method - Google Patents

Abstract

An all-round safety monitoring system and method for lithium ion batteries, including a battery module, a battery health management system, at least one relay and at least one contactor, the battery module is composed of a plurality of single cells in series, the The battery module is used to generate a power source. The battery health management system has a data acquisition unit and a data processing unit. The battery health management system obtains a plurality of pieces of data for each unit battery through the data acquisition unit And through the data processing unit for processing, the relay is used to control the voltage balance of the battery module to avoid the voltage difference between the battery modules, the contactor is arranged between the single cells and The relay is connected, and the battery module connects or disconnects the relay by controlling the closing between the contactors.

Description

Lithium ion battery all-round safety monitoring system and method

The invention relates to the field of a battery grouping process and electronic technology manufacturing, in particular to provide a comprehensive safety monitoring system and method for lithium ion batteries.

First of all, in the field of new energy power supply or energy storage backup power supply, the structure of lithium-ion battery module is an important core component, especially in some fields (such as the field of pure electric vehicles), lithium-ion battery as the only power The source is particularly important. Therefore, the effective module structure of the lithium-ion battery and the comprehensive battery health management (HBMS) can fundamentally improve the cruising range and service life of the power supply or energy storage backup power supply.

Secondly, the battery module structure grouping method can be divided into two types: the first is a module method that is connected in parallel and then in series. According to the capacity and voltage of the lithium-ion battery pack required by the vehicle, the cells are connected in parallel first In series, due to the difference in internal resistance (including the internal resistance of the conductor in the process of the module) and uneven heat dissipation after the parallel connection of the cells, the battery life after parallel connection will be affected. When a unit battery in parallel is shorted, the parallel circuit will be caused The current in is very large, which may easily cause the battery to burn or explode. Of course, this danger has been avoided by fuse protection technology. The second is a module method that connects in series and then in parallel. According to the capacity of the entire group of batteries, the series is first connected, such as 1/3 of the entire group of capacity, and then in parallel. The purpose of this is to reduce the probability of failure of large-capacity battery pack This module method puts forward higher requirements to the management system. In many cases, the stop of charging or discharging of the entire set of batteries is often caused by the weakness of individual batteries in the series circuit.

It can be seen from this that where lithium power batteries in series (or any other type of battery) and large-capacity supercapacitors are used as power or auxiliary power, during the supplement or release of electrical energy, the It is extremely necessary for any single energy storage device to implement independent balanced control, and it is also one of the main technologies that must be solved in the field of new energy applications.

Third, no matter which kind of power supply module structure method, it is necessary to monitor the running state of the battery in an all-round way. It is difficult for the traditional battery management system (BMS) to fully monitor the battery. The module structure also restricts the all-round monitoring of power supply, which is one of the difficulties in the application of new energy power supply.

Secondly, in order to effectively solve the above problems, the main purpose of the present invention is to provide a lithium ion battery comprehensive safety monitoring system that can greatly improve the safety of the system.

The secondary objective of the present invention is to provide a lithium ion battery comprehensive safety monitoring system that has continuous power supply capability during discharge to increase driving range.

The secondary objective of the present invention is to provide a comprehensive safety monitoring system for lithium ion batteries that greatly increases the charging capacity of the lithium ion batteries.

The secondary objective of the present invention is to provide a comprehensive safety monitoring method for lithium ion batteries that greatly improves the safety of the system.

The secondary objective of the present invention is to provide a comprehensive safety monitoring method for a lithium ion battery that has continuous power supply capability during discharge to increase driving range.

The secondary objective of the present invention is to provide a comprehensive safety monitoring method for lithium ion batteries that greatly increases the charging capacity of lithium ion batteries.

To achieve the above objectives, the present invention provides a comprehensive safety monitoring system for lithium ion batteries The control system includes a battery module, a battery health management system, at least one relay and at least one contactor, the battery module is composed of a plurality of single cells in series, the battery module is used to generate a power Power supply, the battery health management system has a data acquisition unit and a data processing unit, the battery health management system obtains a plurality of pieces of data of each unit battery through the data acquisition unit and processes through the data processing unit, The relay is used to control the voltage balance of the battery modules to avoid the voltage difference between the battery modules. The contactor is arranged between the single cells and connected to the relay. The battery The module connects or disconnects the relay by controlling the closing between the contactors.

In order to achieve the above object, the present invention provides a comprehensive safety monitoring method for lithium ion batteries, which includes the following steps: providing a battery health management system with a data processing unit for sending a monitoring command; for a battery module Comprehensive monitoring of multiple data; send the monitored data to a sensing unit and judge whether the data is abnormal; if the data is judged to be abnormal, use the battery health management system to judge whether an alarm is required; if it is If it is judged that an alarm is needed, the health battery management system generates a warning signal according to the data and sends the warning signal to the data processing unit; the data processing unit generates a warning according to the warning signal to prompt or control the The battery module stops power supply and ends the current control flow.

Through the structural design of the present invention, through the control of the battery health management system, the high voltage of the entire system can be safely released to achieve the harmless treatment of the battery in a hazardous environment, and under the monitoring of the battery health management system, each Item data is completely normal to create the entire height Voltage system, and the voltage balance of the battery modules is formed by the control of the relay array to avoid the pressure difference between the entire battery modules in the case of series connection, and finally the contactor between each battery module is controlled to close Then, the relay is opened to complete the establishment of the high-voltage system, which is a series structure of a lithium ion battery comprehensive safety monitoring system. When encountering a dangerous environment, such as battery module water, car accidents, etc., the contact The device will automatically disconnect to realize the high voltage contact of the entire system, and will not cause a dangerous state that the high voltage power supply cannot be disconnected.

The lithium ion battery comprehensive safety monitoring system as described above, through the control of the battery health management system (HBMS), conveniently and comprehensively monitors the status of each single lithium battery, and can control the relay by monitoring the status of the lithium ion battery The switch of the array realizes the single cell balance of the entire system. The balance mode is divided into three modes: static natural balance, energy transfer balance, and passive balance. When the system detects that the individual cells in the same position in each battery module have individual minority voltage inconsistencies, static equilibrium is used; when the system detects that the individual cells in different positions in each battery module have a few voltage inconsistencies , Adopt energy transfer equalization; when the voltage of the majority of single cells of the entire power supply is lower than the voltage of some single cells, these batteries need to be passively balanced to make their voltages consistent with most of the batteries, so as to solve The consistency of battery voltage.

2‧‧‧ battery module

2a, 2b‧‧‧ battery

3‧‧‧Battery health management system

4‧‧‧Relay

5‧‧‧Contactor

14‧‧‧Equalization control module

A1, B1, A2, B2

S801~S810‧‧‧Step

Figure 1 is a structural diagram of the present invention; Figure 2 is a series and parallel structure diagram of the present invention; Figure 3 is a series and parallel equilibrium structure diagram of the present invention; Figure 4 is a system startup of the present invention Electrical diagram of instant relay array; Figure 5 is a flowchart of the present invention.

The above objects, structural and functional characteristics of the present invention will be described based on the preferred embodiments of the accompanying drawings.

Please refer to Figures 1 and 2 for the structure diagram and series and parallel structure diagrams of the lithium ion battery comprehensive safety monitoring system of the present invention. As shown in the figure, a lithium ion battery comprehensive safety monitoring system includes a battery module Group, a battery health management system, at least one relay and at least one contactor, the battery module is composed of a plurality of single cells in series, the battery module is used to generate a power supply, in particular, The unit battery is a unit lithium ion battery; the battery health management system has a data acquisition unit and a data processing unit, and the battery health management system obtains the plural number of each unit battery through the data acquisition unit Pen data and process it through the data processing unit. The battery health management system is used to monitor the voltage and temperature and total current and total voltage of different locations of each single cell in real time. In addition, the battery The health management system further has a sensing unit and a warning unit, the sensing unit is used to sense and analyze whether the battery module is faulty, and generates a warning signal through the warning unit; the relay is used to control the battery The voltage of the module is balanced to avoid the voltage difference between the battery modules; the contactor is arranged between the single cells and connected to the relay, and the battery module controls the contactor by In order to connect or disconnect the relay, in addition, it should be noted that when the contactor between the single cells is closed, the relay will be opened at this time to form a parallel mode; Please refer to Figure 3, which is a series and parallel balanced structure diagram of the comprehensive safety monitoring method of the lithium-ion battery of the present invention, the specific process is as follows:

An equalization control module 14 is composed of an array composed of relays 4, power resistors, and DC-DC converters. The equalization methods include static natural power balance, energy transfer balance, and passive balance. Under different battery operating conditions, different balance control strategies are used. The three balance control strategies are: When the system detects that a few individual cells of the same position in each battery module 2 are inconsistent, a static natural Equalization; when the system detects a few voltage inconsistencies among the cells at different locations in each battery module 2, energy transfer equalization is used; when the voltage of most cells of the entire power supply is lower than some cells At the time of voltage, these batteries need to be passively balanced to make their voltage consistent with most of the batteries, so as to solve the problem of battery voltage consistency.

The first kind of balancing control strategy, the static natural battery balancing control is to achieve the battery balancing between the single cells in the same basic position in the same battery module 2 and the single cells in the same position in different battery modules 2 Between the battery balance.

There is no need to use a DC-DC converter for static power balance control. As shown in FIG. 3, the output of the microprocessor DO controls the opening and closing of each relay 4 in the equalization control module 14 to achieve a static natural battery balance of the battery.

In the second balancing control strategy, when there is a large difference in power between a few single cells, the power battery needs to perform energy transfer balancing.

The energy transfer balance is to realize the power balance between the single cells in different positions in the same basic series branch within the same battery module 2. As shown in FIG. 3, taking cell balancing in the basic series branch A as an example, it is assumed that the battery 2b and the battery 2a in the basic series branch A The battery is not fully charged. The voltage of the basic battery module is connected to the input terminal of the DC-DC converter. The dual-channel relay K1 is connected to the output port of the DC-DC converter. After the coil of the relay K1 is electrically conducted, it is a single unit through the DC-DC converter. The body battery 2b is charged. After the unit battery 2b is fully charged, the relay K1 is turned off, and the relay K2 is turned on, and the unit battery 2a is charged through the DC-DC converter, and then looped in turn until all the unit batteries have reached the same capacity.

The third equalization control strategy, when the voltage of the majority of single cells of the entire power supply is lower than the voltage of some single cells, these cells need to be passively balanced to make their voltages consistent with most of the cells, Solve the consistency problem of battery voltage. As shown in Figure 3, the passive equilibrium control strategy is used as an example for description. In order to make the power of the single cell 1 in the basic series branch A higher than that of all the remaining single cells, passive equalization needs to be performed at this time. At this time, the array of relays 4 and the DC-DC converter in the battery health management system 3 are not activated, and the battery 1 is discharged by the control switch that controls the power resistance of the battery 1 in parallel until the capacity of the battery and the remaining single cells Reach agreement.

Please refer to Fig. 4, which is the electrical diagram of the relay array at the moment of starting the lithium ion battery comprehensive safety monitoring system of the present invention. The relay array is divided into two groups K0-K3 and K4-K7. The relay array control is controlled by the microprocessor DO output control , Divided into two control states:

1. Relay control process during startup.

The main power circuit of the power supply is composed of N single cells connected in series, but due to a certain difference in the voltage of the single cells, there is a large difference between the total positive and the total negative after the power circuit composed of hundreds of series. The voltage difference of several volts or even dozens of volts, in order to avoid this danger, at the instant of start-up, the relay arrays K0-K3 in each battery module 2 are sequentially closed, so that the voltage of each battery module 2 is in a voltage-free State, so that when the main relay is closed, the high The voltage is established to avoid the occurrence of sparking and discharge when there is a voltage difference. After the high voltage is established, the relay 4 array exits operation.

2. The control process of static natural balance relay.

When the power supply does not output power, the high voltage is not established, and equalization is required, the K0-K3 and K4-K7 two sets of relays 4 are sequentially attracted in order to start the equalization of the entire battery module 2.

Please refer to FIG. 5, which is a flowchart of a comprehensive safety monitoring method for lithium ion batteries of the present invention. As shown in the figure, a comprehensive safety monitoring method for lithium ion batteries includes the following steps: S801: Provide a battery health management system A data processing unit is used to send a monitoring command; S802: comprehensive monitoring of multiple data generated by a battery module; S803: transmitting the monitored data to a sensing unit, and judging whether the data is abnormal; S804: If the data is judged to be abnormal, the battery health management system is used to determine whether an alarm is required; S805: If it is judged that an alarm is required, the healthy battery management system generates a warning signal according to the data, and The warning signal is sent to the data processing unit; S806: The data processing unit generates a warning according to the warning signal to prompt or control the battery module to stop power supply, and ends the current round of control process.

In addition, if the data is judged to be abnormal, the battery health management system determines whether an alarm is required and further includes two steps: judging whether activation or equalization control is required, and if so, performing activation or equalization control and ending The current control flow to start the next control flow; Furthermore, after transmitting the monitored data to a sensing unit and determining whether the data is abnormal, it further includes a step: if the data is determined to be normal, it will be transmitted to the data processing unit and there is a When the first voltage is abnormal, a first warning prompt is generated; in addition, after the monitored data is sent to a sensing unit and it is determined whether the data is abnormal, a step is further included: if the data is determined to be normal Is sent to the data processing unit and there is a second voltage abnormality, a second warning prompt is generated, and the battery module is controlled to stop supplying power and continue to be monitored in all directions.

Through the design and step flow of the structure of the present invention, the current of the power supply generated by the battery module is mainly connected in series connection circuit, and the measurement accuracy of voltage, temperature and current is improved through the battery health management system In addition, in order to avoid the overcharge and overdischarge control of the battery module, the sensing unit and the warning unit can be used to determine whether the battery module is faulty. If the fault occurs, the warning unit will generate the warning Signal, in order to achieve a full range of monitoring of the various performances of the system, therefore, the battery health management system can monitor the voltage status of each single cell in real time, and has the ability to analyze battery module faults in real time. The abuse of modules provides early warning and alarm reminders, which facilitates the analysis of the cause of the fault and the location of the fault, and facilitates the maintenance of the battery. In terms of balance, the balance control capability of the battery is increased, and a single battery between battery modules is proposed. Equilibrium method, with equilibrium measures such as static natural equilibrium and passive equilibrium.

In the present invention, the lithium ion battery comprehensive safety monitoring system and its method are used as an example for an electric vehicle (not shown in the figure). When the electric vehicle is started, the battery health management system (HBMS) The entire power supply is monitored in all directions. When the all-round monitoring data is completely normal, a high voltage establishment command is issued. First, the relay starts to generate a closed state After a few seconds, the contactor is also closed. After the closure is completed, the relay is opened to complete the entire power supply series connection and achieve high-voltage establishment; and if the data processing unit finds that there is a problem with the data (such as : The voltage of the single battery is too low, the insulation monitoring warning or the occurrence of a car accident during operation, etc.) can prohibit the closing or instantaneous disconnection of the high voltage state of the entire power supply, to achieve a safe low voltage state of the power supply, to avoid unnecessary unnecessary Secondary injury.

Therefore, through the control of the battery health management system, the high voltage of the entire system can be safely released to achieve the harmless treatment of the battery in a hazardous environment, and under the monitoring of the battery health management system, all the data is completely normal. The entire high-voltage system is established, and the voltage balance of the battery modules is formed by the control of the relay array, to avoid the voltage difference between the entire battery modules in the case of series connection, and finally to control the voltage between each battery module 2 After the contactor is closed, the relay is opened to complete the establishment of the high-voltage system, which is a series structure of a full-range safety monitoring system for a lithium-ion battery. When it encounters a dangerous environment, such as water in the battery module, car accident, etc., The contactor will be automatically disconnected to realize high-voltage contact of the entire system, and will not cause a dangerous state that the high-voltage power supply cannot be disconnected.

The present invention has been described in detail above, but the above is only one of the preferred embodiments of the present invention. When the scope of the present invention cannot be limited, that is, all changes and modifications made in accordance with the scope of the application of the present invention Etc., should still be covered by the patent of the present invention.

S801~S810‧‧‧Step

Claims (11)

A comprehensive safety monitoring system for lithium ion batteries includes: a battery module composed of a plurality of single cells in series, the battery module is used to generate a power source; a battery health management system has a A data acquisition unit and a data processing unit, the battery health management system obtains a plurality of pieces of data of each unit cell through the data acquisition unit and processes the data through the data processing unit; at least one relay is used to control the battery The voltage balance of the battery module to avoid the voltage difference between the battery modules; and at least one contactor is provided between the single cells and connected to the relay, the battery module The relay is connected or disconnected by controlling the closing between the contactors. The lithium ion battery comprehensive safety monitoring system according to claim 1, wherein the single battery is a single lithium ion battery. The omnidirectional safety monitoring system for lithium ion batteries as described in claim 1, wherein when the contactors between the single cells are closed, the relay will be opened at this time to form a parallel connection mode. The lithium ion battery comprehensive safety monitoring system according to claim 1, wherein the battery health management system is used to monitor the voltage and temperature and total current and total voltage of different locations of each single cell in real time . The lithium ion battery comprehensive safety monitoring system according to claim 1, wherein the battery health management system further has a sensing unit and a warning unit, the sensing unit is used to sense and analyze whether the battery module Failure, and generate a warning signal through the warning unit. A comprehensive safety monitoring method for lithium ion batteries, including the following steps: Provide a battery health management system with a data processing unit for sending a monitoring command; comprehensively monitor multiple data generated by a battery module; send the monitored data to a sensing unit, and determine whether the data is Abnormal; if the data is judged to be abnormal, the battery health management system is used to determine whether an alarm is required; if it is judged that an alarm is required, the healthy battery management system generates a warning signal based on the data and sends the warning The signal is sent to the data processing unit; the data processing unit generates a warning according to the warning signal to prompt or control the battery module to stop supplying power, ending the current round of control process. The comprehensive safety monitoring method for lithium-ion batteries as described in claim 6, wherein if the data is judged to be abnormal, the battery health management system further includes two steps after judging whether an alarm is needed: judging whether it is necessary to start or Balance control, if yes, start or balance control, and end the current round of control flow to start the next round of control flow. The omnidirectional safety monitoring method for lithium ion batteries as described in claim 6, wherein after the monitored data is transmitted to a sensing unit and it is determined whether the data is abnormal, a step is further included: if the data is determined to be When it is normal, it will be sent to the data processing unit and there is a first voltage abnormality, and a first warning prompt will be generated. The omnidirectional safety monitoring method for lithium ion batteries as described in claim 6, wherein after the monitored data is transmitted to a sensing unit and it is determined whether the data is abnormal, a step is further included: if the data is determined to be When it is normal, it will be sent to the data processing unit and there is a second voltage abnormality, a second warning prompt is generated, and the battery module is controlled to stop supplying power, and continuous all-round monitoring is performed. The comprehensive safety monitoring method for lithium ion batteries as described in claim 6, wherein when a power source is at rest, the battery modules inside the main circuit are disconnected, and the battery health management system monitors each battery The voltage of the single battery in the module. When the battery voltage in the battery module is poor, the battery health management system controls the relay coil to be energized, the normally open contact is closed, and the power supply is switched in parallel to form the battery. State of equilibrium. The comprehensive safety monitoring method for lithium ion batteries as described in claim 6, wherein when a power supply is in a balanced state, a current limiting balancer can limit the balanced current to a certain current for battery balancing, when the battery is healthy When the management system is in a balanced state, it can comprehensively monitor the status of each lithium-ion battery.

Images