Disclosure of Invention
In order to solve the above problems, the present invention provides a lithium battery protection system and a protection method, which solve the defects in the prior art that the number of interfaces is wasted, the packaging yield is low, and the cost is increased.
The technical scheme adopted by the invention is as follows: a lithium battery protection system, lithium battery protection system includes (n +1) × m batteries and protection chips, the protection chip includes a main protection chip and n from the protection chip, a main protection chip is coupled with m batteries, each is coupled from the protection chip and the m batteries that correspond, main protection chip still is connected with n respectively from the protection chip, lithium battery protection system still includes: the device comprises a detection module, a transmission module and a judgment module;
the detection module is used for triggering a main protection chip or a slave protection chip correspondingly coupled with a certain battery to output an overvoltage protection signal if the detection module detects that the cell voltage of the certain battery exceeds a preset overvoltage protection threshold voltage and the holding time exceeds a set overvoltage protection delay time;
the transmission module is used for transmitting the overvoltage protection signal to the main protection chip;
the main protection chip is used for generating an overvoltage protection hysteresis signal according to the overvoltage protection signal and transmitting the overvoltage protection hysteresis signal to each slave protection chip;
the judging module is used for:
judging whether each slave protection chip is triggered by the detection module to output the overvoltage protection signal;
when the protection chip is triggered, the overvoltage protection threshold voltage of the triggered slave protection chip is adjusted to the overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the chip are opened;
if not, adjusting the triggered overvoltage protection threshold voltage of the slave protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
Preferably, the judging module is further configured to:
judging whether the main protection chip is triggered by the detection module to output the overvoltage protection signal;
when the main protection chip is triggered, the overvoltage protection threshold voltage of the main protection chip is adjusted to an overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the main protection chip are opened;
if not, adjusting the overvoltage protection threshold voltage of the main protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
Preferably, the detection module is further configured to:
after the balancing circuit is opened, detecting whether the corresponding m batteries are all discharged below a set balancing hysteresis threshold or the overvoltage protection signal is cancelled;
and after any condition is reached, all balance circuits of the corresponding m batteries are closed.
Preferably, an under-voltage signal and an under-voltage hysteresis signal are also transmitted between the main protection chip and each of the slave protection chips.
The other technical scheme adopted by the invention is as follows: a protection method of a lithium battery protection system is applied to the lithium battery protection system, and the method comprises the following steps:
if the detection module detects that the cell voltage of a certain battery exceeds a preset overvoltage protection threshold voltage and the holding time exceeds a set overvoltage protection delay time, triggering a main protection chip or a secondary protection chip correspondingly coupled with the battery to output an overvoltage protection signal;
the transmission module transmits the overvoltage protection signal to the main protection chip;
the main protection chip generates an overvoltage protection hysteresis signal according to the overvoltage protection signal and transmits the overvoltage protection hysteresis signal to each slave protection chip;
the judging module judges whether each slave protection chip is triggered by the detecting module to output the overvoltage protection signal;
when the protection chip is triggered, the overvoltage protection threshold voltage of the triggered slave protection chip is adjusted to the overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the chip are opened;
if not, adjusting the triggered overvoltage protection threshold voltage of the slave protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
Preferably, the method further comprises:
judging whether the main protection chip is triggered by the detection module by a judgment module to output the overvoltage protection signal;
when the main protection chip is triggered, the overvoltage protection threshold voltage of the main protection chip is adjusted to an overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the main protection chip are opened;
if not, adjusting the overvoltage protection threshold voltage of the main protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
Preferably, the method further comprises:
after the balancing circuit is opened, the detection module detects whether the corresponding m batteries are all discharged below a set balancing hysteresis threshold or the overvoltage protection signal is cancelled;
and after any condition is reached, all balance circuits of the corresponding m batteries are closed.
Preferably, an under-voltage signal and an under-voltage hysteresis signal are also transmitted between the main protection chip and each of the slave protection chips.
By adopting the technical scheme, the method has the following advantages: according to the lithium battery protection system and the protection method provided by the invention, the balance among the chips is judged according to the overcharge protection signal and the overcharge delay signal among the chips, so that the lithium battery is protected, the number and the types of signals needing to be processed are reduced, and the defects that the number of interfaces is wasted, the packaging yield is low and the cost is increased easily in the prior art are overcome.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific examples, which are used for illustrating the present invention and are not intended to limit the scope of the present invention.
Referring to fig. 1, a lithium battery protection system according to an embodiment of the present invention includes (n +1) × m batteries and protection chips, where the protection chips include a master protection chip and n slave protection chips, one master protection chip is coupled to the m batteries, each slave protection chip is coupled to a corresponding m battery, the master protection chip is further connected to the n slave protection chips, and the lithium battery protection system further includes: the device comprises a detection module, a transmission module and a judgment module;
the detection module is used for triggering a main protection chip or a slave protection chip correspondingly coupled with a certain battery to output an overvoltage protection signal if the detection module detects that the cell voltage of the certain battery exceeds a preset overvoltage protection threshold voltage and the holding time exceeds a set overvoltage protection delay time;
the transmission module is used for transmitting the overvoltage protection signal to the main protection chip;
the main protection chip is used for generating an overvoltage protection hysteresis signal according to the overvoltage protection signal and transmitting the overvoltage protection hysteresis signal to each slave protection chip;
the judging module is used for:
judging whether each slave protection chip is triggered by the detection module to output the overvoltage protection signal;
when the protection chip is triggered, the overvoltage protection threshold voltage of the triggered slave protection chip is adjusted to the overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the chip are opened;
if not, adjusting the triggered overvoltage protection threshold voltage of the slave protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
In practical applications, the overvoltage protection signal may also be output by the main protection chip, so the determining module is further configured to:
judging whether the main protection chip is triggered by the detection module to output the overvoltage protection signal;
when the main protection chip is triggered, the overvoltage protection threshold voltage of the main protection chip is adjusted to an overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the main protection chip are opened;
if not, adjusting the overvoltage protection threshold voltage of the main protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
During application, an under-voltage signal and an under-voltage hysteresis signal are also transmitted between the main protection chip and each slave protection chip, that is, when the lithium battery is protected, the system only needs to acquire four signals, and only the protection mode of the under-voltage signal and the under-voltage hysteresis signal is a basic scheme well known by those skilled in the art, so that the details are not repeated herein; corresponding balancing modules (namely balancing circuits), delay modules and the like are arranged in each chip, and the balancing circuits are independent respectively for the cells connected with the cascaded multi-protection chips. It should be noted that, when the master protection chip or the slave protection chip is not triggered, whether to perform the balancing control on a certain battery is determined according to the states of the corresponding m batteries, specifically including:
if the overvoltage protection signal is not output before, the main chip or the slave chip which receives the overvoltage protection hysteresis signal does not start a balancing circuit if the voltage of m batteries corresponding to the chip is above the balancing threshold voltage or below the balancing threshold voltage; if one battery voltage is higher than the balance threshold voltage, the balance circuit corresponding to the battery is started and discharges the battery core until the balance hysteresis threshold voltage is lower than the balance hysteresis threshold voltage, and the balance circuit is closed. One battery of the characters can be understood as a specific battery or a plurality of batteries, and one chip is correspondingly coupled with one or more batteries; similarly, each chip may correspond to one or more of the corresponding coupled batteries, which is not limited herein.
Through the scheme, the balance among the chips is judged according to the overcharge protection signals and the overcharge delay signals among the chips, so that the lithium battery is protected, the number and the types of signals needing to be processed are reduced, and the defects that in the prior art, the number of interfaces is wasted, the packaging yield is low and the cost is increased are overcome.
Further, the detection module is further configured to:
after the balancing circuit is opened, detecting whether the corresponding m batteries are all discharged below a set balancing hysteresis threshold or the overvoltage protection signal is cancelled;
and after any condition is reached, all balance circuits of the corresponding m batteries are closed.
The application of the detection can avoid over-discharge of the battery, reduce the charging and discharging times of the battery and prolong the service life of the battery.
In summary, compared with the prior art, the scheme reduces clock signals, timing synchronization signals and power signals, the clock signals and the timing synchronization signals in the prior art are used for synchronizing the balance function of each cascade chip, and if the balance state of other cascade chips cannot be identified through the clock signals and the timing synchronization signals, the balance state of other cascade chips is not identified.
Based on the same inventive concept of the above scheme, referring to fig. 2, a protection method for a lithium battery protection system provided by an embodiment of the present invention is applied to the lithium battery protection system, and the method includes:
s101, if the detection module detects that the cell voltage of a certain battery exceeds a preset overvoltage protection threshold voltage and the holding time exceeds a set overvoltage protection delay time, triggering a main protection chip or a secondary protection chip correspondingly coupled with the battery to output an overvoltage protection signal;
s102, the transmission module transmits the overvoltage protection signal to the main protection chip;
s103, the main protection chip generates an overvoltage protection hysteresis signal according to the overvoltage protection signal and transmits the overvoltage protection hysteresis signal to each slave protection chip;
s104, the judging module judges whether each slave protection chip is triggered by the detecting module to output the overvoltage protection signal;
s105, when the protection chip is triggered, the overvoltage protection threshold voltage of the triggered slave protection chip is adjusted to an overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the chip are opened;
and S106, if not triggered, adjusting the triggered overvoltage protection threshold voltage of the slave protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
In practical applications, the overvoltage protection signal may also be output by the main protection chip, so the method further includes:
judging whether the main protection chip is triggered by the detection module to output the overvoltage protection signal;
when the main protection chip is triggered, the overvoltage protection threshold voltage of the main protection chip is adjusted to an overvoltage protection hysteresis threshold, and all balance circuits of m batteries corresponding to the main protection chip are opened;
if not, adjusting the overvoltage protection threshold voltage of the main protection chip to an overvoltage protection hysteresis threshold, and meanwhile, judging whether to perform balance control on a certain battery according to the states of the corresponding m batteries.
During application, an under-voltage signal and an under-voltage hysteresis signal are also transmitted between the main protection chip and each slave protection chip, that is, when the lithium battery is protected, the system only needs to acquire four signals, and only the protection mode of the under-voltage signal and the under-voltage hysteresis signal is a basic scheme well known by those skilled in the art, so that the details are not repeated herein; corresponding balancing modules (namely balancing circuits), delay modules and the like are arranged in each chip, and the balancing circuits are independent respectively for the cells connected with the cascaded multi-protection chips. It should be noted that, when the master protection chip or the slave protection chip is not triggered, whether to perform the balancing control on a certain battery is determined according to the states of the corresponding m batteries, specifically including:
if the overvoltage protection signal is not output before, the main chip or the slave chip which receives the overvoltage protection hysteresis signal does not start a balancing circuit if the voltage of m batteries corresponding to the chip is above the balancing threshold voltage or below the balancing threshold voltage; if one battery voltage is higher than the balance threshold voltage, the balance circuit corresponding to the battery is started and discharges the battery core until the balance hysteresis threshold voltage is lower than the balance hysteresis threshold voltage, and the balance circuit is closed. One battery of the characters can be understood as a specific battery or a plurality of batteries, and one chip is correspondingly coupled with one or more batteries; similarly, each chip may correspond to one or more of the corresponding coupled batteries, which is not limited herein.
According to the scheme, the balance among the chips is judged according to the overcharge protection signals and the overcharge delay signals among the chips, so that the lithium battery is protected, clock signals, time sequence synchronous signals and power signals are reduced compared with the prior art, the clock signals and the time sequence synchronous signals in the prior art are used for synchronizing the balance function of each cascade chip, if the balance state of other cascade chips cannot be identified through the clock signals and the time sequence synchronous signals, the number and the types of signals needing to be processed are reduced, the defects that in the prior art, the number of interfaces is wasted, the packaging yield is low, and the cost is increased are overcome.
Further, the detection module is further configured to:
after the balancing circuit is opened, detecting whether the corresponding m batteries are all discharged below a set balancing hysteresis threshold or the overvoltage protection signal is cancelled;
and after any condition is reached, all balance circuits of the corresponding m batteries are closed.
The step of detection is applied, so that the over-discharge of the battery can be avoided, the charging and discharging times of the battery are reduced, and the service life of the battery is prolonged.
Those of ordinary skill in the art will appreciate that the system modules and method steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
Finally, it should be noted that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.