Control method and device based on the variable current discharge state of iron-lithium battery and base station power supply system

Abstract

The present invention provides a control method, device and base station power supply system based on the variable current discharge state of an iron-lithium battery. The iron-lithium battery control device includes a lithium battery terminal voltage data acquisition module, an iron-lithium battery current acquisition module, a switch array, an adjustable voltage and current device and a control processor; the method includes measuring the cell voltage of each lithium battery when the lithium battery is in the variable current discharge state, and analyzing the difference between the cell voltage of a lithium battery and the first average voltage to determine whether the lithium battery is in a state where the cell voltage drops quickly and the capacity is insufficient, and then processing such lithium batteries until all lithium batteries do not have a situation where the cell voltage drops quickly and the capacity is much lower than other lithium batteries. The present invention solves the problem that the individual cells of the iron-lithium battery discharge quickly, thereby affecting the performance and life of the iron-lithium battery.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a control method and device based on the variable current discharge state of an iron-lithium battery and a base station power supply system. Background Art

[0002] Communication base stations generally use lithium iron batteries as backup power sources to ensure that the communication base stations can continue to operate normally in the event of a main power failure or power outage.

[0003] However, the consistency of different batches of lithium-iron batteries provided by lithium-iron battery manufacturers cannot be guaranteed. In addition, when the lithium-iron battery is used as a backup battery and discharged, the discharge speed of each battery cell is usually different. The battery cell with a fast discharge speed will be discharged first, while other batteries with a slow discharge speed may still have power. According to the barrel principle, the capacity of the entire battery pack depends on the battery cell that is discharged first, resulting in a decrease in the overall capacity utilization rate and the inability to fully utilize the power storage capacity of all batteries. In addition, batteries with a fast discharge speed will be subjected to greater pressure, and the internal chemical reaction will be more intense, which will accelerate the aging process of the battery cell. Since the battery pack is a whole, the rapid aging of a battery cell will affect the performance and life of the entire lithium-iron battery. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a control method based on the variable current discharge state of an iron-lithium battery, which solves the problem in the prior art that the discharge speeds of various cells of the iron-lithium battery are inconsistent, thereby affecting the performance and life of the iron-lithium battery.

[0005] According to an embodiment of the present invention, a first aspect provides a control method based on the variable current discharge state of an iron-lithium battery, which is applied to an iron-lithium battery control device, wherein the iron-lithium battery control device includes a lithium battery cell terminal voltage data acquisition module, an iron-lithium battery through current acquisition module, a switch array, an adjustable voltage and current device, and a control processor; the iron-lithium battery includes N lithium batteries connected in series; the lithium battery cell terminal voltage data acquisition module acquires the cell voltage of each lithium battery cell, and the iron-lithium battery through current acquisition module acquires the through current of the iron-lithium battery, and the switch array includes N+1 array switches, and the positive electrode of each lithium battery cell and the negative electrode of each lithium battery cell are connected to an array switch. one end of the 2n-1 array switch is connected, wherein one end of the 2n-1 array switch is connected to the positive electrode of a lithium battery cell, and one end of the 2n array switch is connected to the negative electrode of the lithium battery cell; the adjustable voltage and current device includes a first positive switch, a second positive switch, a first negative switch and a second negative switch, the first positive switch is connected to the other end of the 2n-1 array switch, the second positive switch is connected to the other end of the 2n array switch, the first negative switch is connected to the other end of the 2n-1 array switch, and the second negative switch is connected to the other end of the 2n array switch; wherein N is a positive integer, and n is a positive integer less than or equal to N;

[0006] The lithium iron battery control method based on the adjustable voltage and current device includes:

[0007] S1, when the lithium iron battery is in a variable current discharge state, measuring the cell voltage of each lithium battery cell, and calculating a first average voltage based on N lithium battery cells, and a difference between the cell voltage of each lithium battery cell and the first average voltage;

[0008] S2. If the difference between the cell voltage of the nth lithium battery cell and the first average voltage is less than zero, and the absolute value of the difference between the cell voltage of the nth lithium battery cell and the first average voltage is greater than a first threshold, and the cell voltage of the nth lithium battery cell is lower than the cell voltages of the remaining lithium batteries, then adjust the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current meter so that the adjustable voltage and current meter is connected in parallel with the nth lithium battery cell, and then calculate the current value and voltage value of the adjustable voltage and current meter and set them;

[0009] S3, measuring the target voltage across the nth lithium battery cell after the nth lithium battery cell is connected in parallel with the adjustable voltage and current device set in S2, and calculating the second average voltage based on the target voltage and the cell voltages of the remaining lithium batteries measured in S1, and the difference between the target voltage and the second average voltage;

[0010] S4. If the difference between the target voltage and the second average voltage is greater than 0 and less than a second threshold, the first positive switch, the second positive switch, the first negative switch, the second negative switch and the N+1 array switches of the adjustable voltage and current device are adjusted to terminate the connection relationship between the adjustable voltage and current device and the nth lithium battery cell; if the difference between the target voltage and the second average voltage is less than or equal to 0, the connection relationship between the adjustable voltage and current device and the nth lithium battery cell is maintained;

[0011] S5. Repeat S1 to S4 until the difference between the cell voltage of any lithium battery cell and the first average voltage is greater than or equal to 0, or the difference between the cell voltage of any lithium battery cell and the first average voltage is less than 0, and its absolute value is less than or equal to the first threshold.

[0012] Optionally, adjusting the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current device so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell includes:

[0013] If the serial number of the nth lithium battery cell is an odd number, the first positive switch and the second negative switch are closed to detect whether the first multiple connection line is positive and the second multiple connection line is negative; if so, the first positive switch and the second negative switch are opened, and the 2n-1th array switch and the 2nth array switch are controlled to be closed, and it is detected again whether the first multiple connection line is positive and the second multiple connection line is negative; if still, the first positive switch, the second negative switch, the 2n-1th array switch and the 2nth array switch are controlled to be closed, so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell;

[0014] If the serial number of the nth lithium battery cell is an even number, the second positive switch and the first negative switch are closed to detect whether the first multiple connection line is the negative pole and the second multiple connection line is the positive pole; if so, the second positive switch and the first negative switch are opened, and the 2nth array switch and the 2n+1th array switch are controlled to be closed, and the first multiple connection line is the negative pole and the second multiple connection line is the positive pole are detected again; if still, the second positive switch, the first negative switch, the 2nth array switch and the 2n+1th array switch are controlled to be closed, so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell;

[0015] Among them, the connection between the first positive switch, the second positive switch and the array switch of the adjustable voltage and current device is a first complex connection; the connection between the first negative switch, the second negative switch and the array switch of the adjustable voltage and current device is a second complex connection.

[0016] Optionally, when the serial number of the nth lithium battery cell is an odd number, if the condition that the first multiple connection line is a positive electrode and the second multiple connection line is a negative electrode is not met, a wiring error is reported;

[0017] When the serial number of the nth lithium battery cell is an even number, if the condition that the first multiple connection line is the negative pole and the second multiple connection line is the positive pole is not met, a wiring error is reported.

[0018] Optionally, calculating the voltage value of the adjustable voltage and current device includes:

[0019] Subtracting the cell voltage of the nth lithium battery cell from the first average voltage to obtain a standby voltage value;

[0020] At every preset time interval, record the average value of the sampled voltage;

[0021] According to the average values ​​of multiple sampled voltages recorded within multiple preset times and the standby voltage value, the voltage value of the adjustable voltage and current device is outputted, and the formula is:

[0022] Vε=Vα+(M1+M2+...+M 20 ) / 20

[0023] Wherein, M1 is the average value of the sampled voltage recorded in the first preset time, M2 is the average value of the sampled voltage recorded in the second preset time, ..., M 20 is the average value of the sampled voltage recorded within the twentieth preset time, Vε is the voltage value of the adjustable voltage and current device obtained using the second control function, and Vα is the standby voltage value.

[0024] Optionally, calculating the current value of the adjustable voltage and current device includes:

[0025] Record the average value of the sampled current at each preset time interval;

[0026] The standby current value is calculated based on the average value of multiple sampled currents recorded within multiple preset times:

[0027] The current value of the adjustable voltage and current device is outputted according to the standby current value and the voltage value of the adjustable voltage and current device.

[0028] Optionally, the standby current value is calculated according to the average value of multiple sampled currents recorded within multiple preset time periods, and the formula is:

[0029] IN=(I△t1+I△t2+...+I△t 20 ) / 20;

[0030] Where, IN is the standby current value, △t1 is the first minute within 20 minutes, △t2 is the second minute within 20 minutes, ..., △t 20The twentieth minute within 20 minutes.

[0031] Optionally, outputting the current value of the adjustable voltage and current device according to the standby current value and the voltage value of the adjustable voltage and current device comprises:

[0032] If the standby current value is less than the first standard current, the voltage value of the adjustable voltage and current device is calculated by dividing the voltage value of the adjustable voltage and current device by the first preset current value of the first resistance value; and when the first preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=3; when the first preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=Vε / R1+3;

[0033] If the standby current value is greater than or equal to the first standard current and less than the second standard current, the voltage value of the adjustable voltage and current meter is divided by the second preset current value of the second resistance value; and when the second preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current meter is: Iε=5+IN / 30; when the second preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current meter is: Iε=Vε / R1+IN / 15;

[0034] If the standby current value is greater than or equal to the second standard current and less than the third standard current, the voltage value of the adjustable voltage and current device is calculated by dividing the third preset current value of the third resistance value; and when the third preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=7+IN / 30; when the third preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=Vε / R2+IN / 30;

[0035] If the standby current value is greater than or equal to the third standard current, the current value of the adjustable voltage and current device is calculated as follows: Iε=8+IN / 50;

[0036] Wherein, Iε is the current value of the adjustable voltage and current device, Vε is the voltage value of the adjustable voltage and current device, IN is the standby current value, R1 is the first resistance value, and R2 is the second resistance value.

[0037] Optionally, adjusting the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current device to terminate the connection relationship between the adjustable voltage and current device and the nth lithium battery cell includes:

[0038] If the serial number of the nth lithium battery cell is an odd number, the 2n-1th array switch and the 2nth array switch, as well as the first positive switch and the second negative switch are turned on to detect whether there is voltage between the first double line and the second double line. If so, a wiring error is reported. If not, the first positive switch and the second negative switch are kept turned on to terminate the connection between the adjustable voltage and current device and the nth lithium battery cell.

[0039] If the serial number of the nth lithium battery cell is an even number, the 2nth array switch and the 2n+1th array switch, as well as the second positive switch and the first negative switch are turned on to detect whether there is voltage between the first double line and the second double line. If so, a wiring error is reported; if not, the second positive switch and the first negative switch are kept open to terminate the connection between the adjustable voltage and current meter and the nth lithium battery cell.

[0040] The second aspect provides a control device based on the conversion discharge state of an iron-lithium battery, which is applied to a control processor of the iron-lithium battery control device, wherein the iron-lithium battery control device also includes a lithium battery cell terminal voltage data acquisition module, an iron-lithium battery current acquisition module, a switch array and an adjustable voltage and current device; the control processor executes a control method based on the conversion discharge state of an iron-lithium battery as described in any of the above items.

[0041] A third aspect provides a base station power supply system, including a base station power supply device and an iron-lithium battery control device;

[0042] The base station power supply device is connected to both ends of the power load, including a communication power supply and an iron-lithium battery, wherein the iron-lithium battery includes N lithium cells connected in series;

[0043] The iron-lithium battery control device and the iron-lithium battery are both connected to the two ends of the communication power supply, the iron-lithium battery serves as a backup power supply for the communication power supply, the communication power supply and the iron-lithium battery both supply power to the communication load, and the communication power supply also supplies power to the iron-lithium battery control device;

[0044] The control processor of the iron-lithium battery control device executes the control method based on the variable current discharge state of the iron-lithium battery as described in any one of the above items.

[0045] The present invention has the following beneficial effects: when the lithium battery is in a variable current discharge state, the cell voltage of each lithium battery cell is measured, and by analyzing the difference between the cell voltage of a lithium battery cell and the first average voltage, it is determined whether the lithium battery cell is in a state where the cell voltage drops rapidly and the capacity is insufficient, and then such lithium batteries are processed until all lithium batteries do not have a situation where the cell voltage drops rapidly and the capacity is much lower than that of other lithium batteries. The processing method is: control the first positive switch, the second positive switch, the first negative switch, and the second negative switch of the array switch and the adjustable voltage and current device, connect the adjustable voltage and current device in parallel with the nth lithium battery cell, supplement the current of the nth lithium battery cell, slow down the cell voltage drop speed of the nth lithium battery cell, so that the cell voltage drop speed of each lithium battery cell converges to the same consistency during the discharge process of the iron-lithium battery, and avoid the problem that the voltage drop speed of individual lithium batteries is fast, resulting in the performance decline and significant shortening of the life of the entire iron-lithium battery. Then, the second threshold is used to determine whether the regulation of the nth lithium battery cell has achieved the purpose. If there is no need to further slow down the voltage drop rate, the array switch and the switch of the adjustable voltage and current device are controlled to separate the adjustable voltage and current device from the iron-lithium battery circuit, that is, to terminate the connection between the adjustable voltage and current device and the nth lithium battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the implementation flow of the control method based on the variable current discharge state of the iron-lithium battery according to an embodiment of the present invention;

[0047] Figure 2 A structural diagram of a lithium iron battery control device according to another embodiment of the present invention;

[0048] Figure 3 This is a structural diagram of a base station power supply system according to another embodiment of the present invention. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0050] like Figure 1 As shown, the embodiment of the present invention proposes a control method based on the variable current discharge state of the iron-lithium battery, which is applied to Figure 2 In the lithium iron battery control device shown in the figure, Figure 2 The lithium iron battery control device shown is described.

[0051] like Figure 2 As shown, the lithium iron battery control device includes a lithium battery terminal voltage data acquisition module 21, a lithium iron battery current acquisition module 22, a switch array 23, an adjustable voltage and current device 24 and a control processor 25; the lithium iron battery D includes N lithium batteries d connected in series NThe connection relationship of the above parts is as follows: The lithium battery terminal voltage data acquisition module 21 collects the voltage of each lithium battery d n The voltage of the iron-lithium battery D is collected by the current collection module 22, and the switch array 23 includes N+1 array switches K N+1 , each lithium battery d N The positive electrode and each lithium battery cell N The negative poles are connected to an array switch K N+1 One end of the array switch K 2n-1 One end is connected to a lithium battery d n The positive pole of the 2nth array switch K 2n One end is connected to a lithium battery d n The adjustable voltage current device 24 includes a first positive switch KA1, a second positive switch KA2, a first negative switch KA3 and a second negative switch KA4, and also includes a control terminal F electrically connected to the control processor 25. The first positive switch KA1 and the 2n-1th array switch K 2n-1 The other end of the second positive switch KA2 is connected to the 2nth array switch K 2n The other end of the first cathode switch KA3 is connected to the 2n-1th array switch K 2n-1 The other end of the second cathode switch KA4 is connected to the 2nth array switch K 2n The other end of the connection.

[0052] Wherein, N is a positive integer, and n is a positive integer less than or equal to N.

[0053] Based on this, Figure 1 As shown, the control method based on the variable current discharge state of the iron-lithium battery includes but is not limited to the following steps:

[0054] S1, when the lithium iron battery is in a variable current discharge state, measuring the cell voltage of each lithium battery cell, and calculating a first average voltage based on N lithium battery cells, and a difference between the cell voltage of each lithium battery cell and the first average voltage;

[0055] S2. If the difference between the cell voltage of the nth lithium battery cell and the first average voltage is less than zero, and the absolute value of the difference between the cell voltage of the nth lithium battery cell and the first average voltage is greater than a first threshold, and the cell voltage of the nth lithium battery cell is lower than the cell voltages of the remaining lithium batteries, then adjust the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current meter so that the adjustable voltage and current meter is connected in parallel with the nth lithium battery cell, and then calculate the current value and voltage value of the adjustable voltage and current meter and set them;

[0056] S3, measuring the target voltage across the nth lithium battery cell after the nth lithium battery cell is connected in parallel with the adjustable voltage and current device set in S2, and calculating the second average voltage based on the target voltage and the cell voltages of the remaining lithium batteries measured in S1, and the difference between the target voltage and the second average voltage;

[0057] S4. If the difference between the target voltage and the second average voltage is greater than 0 and less than a second threshold, the first positive switch, the second positive switch, the first negative switch, the second negative switch and the N+1 array switches of the adjustable voltage and current device are adjusted to terminate the connection relationship between the adjustable voltage and current device and the nth lithium battery cell; if the difference between the target voltage and the second average voltage is less than or equal to 0, the connection relationship between the adjustable voltage and current device and the nth lithium battery cell is maintained;

[0058] S5. Repeat S1 to S4 until the difference between the cell voltage of any lithium battery cell and the first average voltage is greater than or equal to 0, or the difference between the cell voltage of any lithium battery cell and the first average voltage is less than 0, and its absolute value is less than or equal to the first threshold.

[0059] For the above step S1, the difference between the cell voltage of each lithium battery cell and the first average voltage is greater than or equal to 0 and less than 0. Based on step S2, the embodiment of the present invention further analyzes the situation that the difference between the cell voltage of the nth lithium battery cell and the first average voltage is less than 0, determines whether the cell voltage of the nth lithium battery cell decreases faster, and further determines whether its capacity is much lower than other lithium batteries through the first threshold.

[0060] In one embodiment, the first threshold in the above step S2 is exemplarily 0.3.

[0061] Based on Figure 2 In the lithium iron battery control device shown in the above step S2, the first positive switch, the second positive switch, the first negative switch, the second negative switch and the N+1 array switches of the adjustable voltage and current device are adjusted so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell. One implementation method is:

[0062] S21, if the serial number of the nth lithium battery cell is an odd number, close the first positive switch and the second negative switch, and detect whether the first multiple connection line is positive and the second multiple connection line is negative; if so, open the first positive switch and the second negative switch, and control the 2n-1th array switch and the 2nth array switch to be closed, and detect again whether the first multiple connection line is positive and the second multiple connection line is negative; if still, control the first positive switch, the second negative switch, the 2n-1th array switch and the 2nth array switch to be closed, so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell;

[0063] S22, if the serial number of the nth lithium battery cell is an even number, close the second positive switch and the first negative switch, and detect whether the first multiple connection line is the negative pole and the second multiple connection line is the positive pole; if so, open the second positive switch and the first negative switch, and control the 2nth array switch and the 2n+1th array switch to be closed, and detect again whether the first multiple connection line is the negative pole and the second multiple connection line is the positive pole; if still, control the second positive switch, the first negative switch, the 2nth array switch and the 2n+1th array switch to be closed, so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell;

[0064] Among them, the connection between the first positive switch, the second positive switch and the array switch of the adjustable voltage and current device is a first complex connection; the connection between the first negative switch, the second negative switch and the array switch of the adjustable voltage and current device is a second complex connection.

[0065] In one embodiment, when the serial number of the nth lithium battery cell is odd, if the condition that the first multiple connection line is the positive electrode and the second multiple connection line is the negative electrode is not met, a wiring error is reported;

[0066] When the serial number of the nth lithium battery cell is an even number, if the condition that the first multiple connection line is the negative pole and the second multiple connection line is the positive pole is not met, a wiring error is reported.

[0067] For the above step S2, calculating the voltage value of the adjustable voltage and current device includes:

[0068] Subtracting the cell voltage of the nth lithium battery cell from the first average voltage to obtain a standby voltage value;

[0069] At every preset time interval, record the average value of the sampled voltage;

[0070] According to the average values ​​of multiple sampled voltages recorded within multiple preset times and the standby voltage value, the voltage value of the adjustable voltage and current device is outputted, and the formula is:

[0071] Vε=Vα+(M1+M2+...+M 20 ) / 20

[0072] Wherein, M1 is the average value of the sampled voltage recorded in the first preset time, M2 is the average value of the sampled voltage recorded in the second preset time, ..., M 20 is the average value of the sampled voltage recorded within the twentieth preset time, Vε is the voltage value of the adjustable voltage and current device obtained using the second control function, and Vα is the standby voltage value.

[0073] The above step S2 calculates the current value of the adjustable voltage and current device, including:

[0074] Record the average value of the sampled current at each preset time interval;

[0075] The standby current value is calculated based on the average value of multiple sampled currents recorded within multiple preset times:

[0076] The current value of the adjustable voltage and current device is outputted according to the standby current value and the voltage value of the adjustable voltage and current device.

[0077] In the embodiment of the present invention, the preset time is 1 minute, and the average value of the sampled currents with a 1-minute interval can be obtained and recorded in the historical data to obtain the average values ​​of multiple sampled currents within 20 minutes. Based on this, the standby current value is calculated according to the average values ​​of multiple sampled currents recorded within multiple preset times, and the formula is:

[0078] IN=(I△t1+I△t2+...+I△t 20 ) / 20;

[0079] Where, IN is the standby current value, △t1 is the first minute within 20 minutes, △t2 is the second minute within 20 minutes, ..., △t 20 The twentieth minute within 20 minutes.

[0080] It should be noted that when using the second control function to calculate the current value of the adjustable voltage and current meter, if the execution time of outputting the current value of the adjustable voltage and current meter based on the standby current value and the voltage value of the adjustable voltage and current meter exceeds 5 minutes, then return to re-record the sampled current average value.

[0081] Wherein, outputting the current value of the adjustable voltage and current device according to the standby current value and the voltage value of the adjustable voltage and current device comprises:

[0082] If the standby current value is less than the first standard current, the voltage value of the adjustable voltage and current device is calculated by dividing the voltage value of the adjustable voltage and current device by the first preset current value of the first resistance value; and when the first preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=3; when the first preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=Vε / R1+3;

[0083] If the standby current value is greater than or equal to the first standard current and less than the second standard current, the voltage value of the adjustable voltage and current meter is divided by the second preset current value of the second resistance value; and when the second preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current meter is: Iε=5+IN / 30; when the second preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current meter is: Iε=Vε / R1+IN / 15;

[0084] If the standby current value is greater than or equal to the second standard current and less than the third standard current, the voltage value of the adjustable voltage and current device is calculated by dividing the third preset current value of the third resistance value; and when the third preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=7+IN / 30; when the third preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=Vε / R2+IN / 30;

[0085] If the standby current value is greater than or equal to the third standard current, the current value of the adjustable voltage and current device is calculated as follows: Iε=8+IN / 50;

[0086] Wherein, Iε is the current value of the adjustable voltage and current device, Vε is the voltage value of the adjustable voltage and current device, IN is the standby current value, R1 is the first resistance value, and R2 is the second resistance value. In a better implementation, the first standard current is 15, the second standard current is 30, the third standard current is 50, the first preset current value is Vε / R1, the second preset current value is Vε / R2, the third preset current value is Vε / R3, the first resistance value R1 is 0.05Ω, the second resistance value R2 is 0.07Ω, and the third resistance value R3 is 0.09Ω.

[0087] For the above-mentioned step S3, after the nth lithium battery cell of the embodiment of the present invention is connected in parallel with the adjustable voltage and current device set in S2, the decreasing speed of the battery cell voltage of the nth lithium battery cell is slowed down, and the difference between the target voltage of the nth lithium battery cell and the second average voltage will gradually approach 0 from a negative value and continue to rise.

[0088] For the above-mentioned step S4, an embodiment of the present invention stipulates that when the difference between the target voltage of the nth lithium battery cell and the cell voltage of the nth lithium battery cell is higher than 0 and within the second threshold value, the connection relationship between the adjustable voltage and current device and the nth lithium battery cell is terminated, and the decreasing speed of the cell voltage of the nth lithium battery cell is no longer slowed down by the adjustable voltage and current device.

[0089] In one embodiment, the second threshold in the above step S4 is exemplarily 0.3.

[0090] In one embodiment, in the above step S4, adjusting the first positive switch, the second positive switch, the first negative switch, the second negative switch and the N+1 array switches of the adjustable voltage and current device to terminate the connection relationship between the adjustable voltage and current device and the nth lithium battery cell, the implementation method includes:

[0091] S41, if the serial number of the nth lithium battery cell is an odd number, open the 2n-1th array switch and the 2nth array switch, as well as the first positive switch and the second negative switch, and detect whether there is voltage between the first double line and the second double line. If so, report a wiring error. If not, keep the first positive switch and the second negative switch open, and end the connection relationship between the adjustable voltage and current meter and the nth lithium battery cell;

[0092] S42. If the serial number of the nth lithium battery cell is an even number, the 2nth array switch and the 2n+1th array switch, as well as the second positive switch and the first negative switch are turned on to detect whether there is voltage between the first double line and the second double line. If so, a wiring error is reported; if not, the second positive switch and the first negative switch are kept turned on to terminate the connection between the adjustable voltage and current meter and the nth lithium battery cell.

[0093] For the above step S5, the embodiment of the present invention performs the above steps S1 to S5 on each of the N lithium cells of the iron-lithium battery with a faster cell voltage drop rate, so as to achieve the control purpose of making the cell voltage of each lithium cell converge to the same consistency during the discharge process.

[0094] Another embodiment of the present invention provides a control device based on the current conversion discharge state of an iron-lithium battery, which is applied to a control processor of the iron-lithium battery control device, wherein the iron-lithium battery control device also includes a lithium battery cell terminal voltage data acquisition module, an iron-lithium battery current acquisition module, a switch array and an adjustable voltage and current device; the control processor executes any of the above control methods based on the current conversion discharge state of the iron-lithium battery.

[0095] like Figure 3 As shown, the embodiment of the present invention further provides a base station power supply system, including a base station power supply device 31 and an iron-lithium battery control device 32;

[0096] The base station power supply device 31 is connected to both ends of the power load, and includes a communication power supply 311 and an iron-lithium battery 312, wherein the iron-lithium battery 312 includes N lithium cells connected in series;

[0097] The iron-lithium battery control device 32 and the iron-lithium battery 312 are both connected to the two ends of the communication power supply 311, and the iron-lithium battery 312 serves as a backup power supply for the communication power supply 311. The communication power supply 311 and the iron-lithium battery 312 both supply power to the communication load, and the communication power supply 311 also supplies power to the iron-lithium battery 312 control device;

[0098] The control processor of the iron-lithium battery control device 32 executes any of the above control methods based on the variable current discharge state of the iron-lithium battery.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A control method based on the variable current discharge state of an iron-lithium battery, characterized in that: Applicable to a lithium iron battery control device, the lithium iron battery control device includes a lithium battery terminal voltage data acquisition module, a lithium iron battery current acquisition module, a switch array, an adjustable voltage and current device and a control processor; the lithium iron battery includes N lithium batteries connected in series; the lithium battery terminal voltage data acquisition module acquires the battery voltage of each lithium battery, the lithium iron battery current acquisition module acquires the current of the lithium iron battery, the switch array includes N+1 array switches, the positive electrode of each lithium battery and the negative electrode of each lithium battery are connected to one end of an array switch, wherein the 2n-1th array switch One end of the switch is connected to the positive electrode of a lithium battery cell, and one end of the 2nth array switch is connected to the negative electrode of the lithium battery cell; the adjustable voltage and current device includes a first positive switch, a second positive switch, a first negative switch and a second negative switch, the first positive switch is connected to the other end of the 2n-1th array switch, the second positive switch is connected to the other end of the 2n-1th array switch, the first negative switch is connected to the other end of the 2n-1th array switch, and the second negative switch is connected to the other end of the 2nth array switch; wherein N is a positive integer, and n is a positive integer less than or equal to N; The lithium iron battery control method based on the adjustable voltage and current device includes: S1, when the lithium iron battery is in a variable current discharge state, measuring the cell voltage of each lithium battery cell, and calculating a first average voltage based on N lithium battery cells, and a difference between the cell voltage of each lithium battery cell and the first average voltage; S2. If the difference between the cell voltage of the nth lithium battery cell and the first average voltage is less than zero, and the absolute value of the difference between the cell voltage of the nth lithium battery cell and the first average voltage is greater than a first threshold, and the cell voltage of the nth lithium battery cell is lower than the cell voltages of the remaining lithium batteries, then adjust the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current meter so that the adjustable voltage and current meter is connected in parallel with the nth lithium battery cell, and then calculate the current value and voltage value of the adjustable voltage and current meter and set them; S3, measuring the target voltage across the nth lithium battery cell after the nth lithium battery cell is connected in parallel with the adjustable voltage and current device set in S2, and calculating the second average voltage based on the target voltage and the cell voltages of the remaining lithium batteries measured in S1, and the difference between the target voltage and the second average voltage; S4. If the difference between the target voltage and the second average voltage is greater than 0 and less than a second threshold, the first positive switch, the second positive switch, the first negative switch, the second negative switch and the N+1 array switches of the adjustable voltage and current device are adjusted to terminate the connection relationship between the adjustable voltage and current device and the nth lithium battery cell; if the difference between the target voltage and the second average voltage is less than or equal to 0, the connection relationship between the adjustable voltage and current device and the nth lithium battery cell is maintained; S5. Repeat S1 to S4 until the difference between the cell voltage of any lithium battery cell and the first average voltage is greater than or equal to 0, or the difference between the cell voltage of any lithium battery cell and the first average voltage is less than 0, and its absolute value is less than or equal to the first threshold.

2. The control method based on the variable current discharge state of the iron-lithium battery according to claim 1, characterized in that: The method of adjusting the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current device so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell includes: If the serial number of the nth lithium battery cell is an odd number, the first positive switch and the second negative switch are closed to detect whether the first multiple connection line is positive and the second multiple connection line is negative; if so, the first positive switch and the second negative switch are opened, and the 2n-1th array switch and the 2nth array switch are controlled to be closed, and it is detected again whether the first multiple connection line is positive and the second multiple connection line is negative; if still, the first positive switch, the second negative switch, the 2n-1th array switch and the 2nth array switch are controlled to be closed, so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell; If the serial number of the nth lithium battery cell is an even number, the second positive switch and the first negative switch are closed to detect whether the first multiple connection line is the negative pole and the second multiple connection line is the positive pole; if so, the second positive switch and the first negative switch are opened, and the 2nth array switch and the 2n+1th array switch are controlled to be closed, and the first multiple connection line is the negative pole and the second multiple connection line is the positive pole are detected again; if still, the second positive switch, the first negative switch, the 2nth array switch and the 2n+1th array switch are controlled to be closed, so that the adjustable voltage and current device is connected in parallel with the nth lithium battery cell; Among them, the connection between the first positive switch, the second positive switch and the array switch of the adjustable voltage and current device is a first complex connection; the connection between the first negative switch, the second negative switch and the array switch of the adjustable voltage and current device is a second complex connection.

3. The control method based on the variable current discharge state of the iron-lithium battery as claimed in claim 2 is characterized in that: When the serial number of the nth lithium battery cell is odd, if the condition that the first multiple connection line is positive and the second multiple connection line is negative is not met, a wiring error is reported; When the serial number of the nth lithium battery cell is an even number, if the condition that the first multiple connection line is the negative pole and the second multiple connection line is the positive pole is not met, a wiring error is reported.

4. The control method based on the iron-lithium battery according to claim 1, characterized in that: Calculating the voltage value of the adjustable voltage and current device includes: Subtracting the cell voltage of the nth lithium battery cell from the first average voltage to obtain a standby voltage value; At every preset time interval, record the average value of the sampled voltage; According to the average values ​​of multiple sampled voltages recorded within multiple preset times and the standby voltage value, the voltage value of the adjustable voltage and current device is outputted, and the formula is: Vε=Vα+(M1+M2+...+M 20 ) / 20 Wherein, M1 is the average value of the sampled voltage recorded in the first preset time, M2 is the average value of the sampled voltage recorded in the second preset time, ..., M 20 is the average value of the sampled voltage recorded within the twentieth preset time, Vε is the voltage value of the adjustable voltage and current device obtained using the second control function, and Vα is the standby voltage value.

5. The control method based on the iron-lithium battery according to claim 4, characterized in that: Calculating the current value of the adjustable voltage and current device includes: Record the average value of the sampled current at each preset time interval; The standby current value is calculated based on the average value of multiple sampled currents recorded within multiple preset times: The current value of the adjustable voltage and current device is outputted according to the standby current value and the voltage value of the adjustable voltage and current device.

6. The control method based on the iron-lithium battery according to claim 5, characterized in that: The standby current value is calculated based on the average value of multiple sampled currents recorded within multiple preset times. The formula is: IN=(I△t1+I△t2+...+I△t 20 ) / 20; Where, IN is the standby current value, △t1 is the first minute within 20 minutes, △t2 is the second minute within 20 minutes, ..., △t 20 The twentieth minute within 20 minutes.

7. The control method based on the iron-lithium battery according to claim 5, characterized in that: Outputting the current value of the adjustable voltage and current device according to the standby current value and the voltage value of the adjustable voltage and current device comprises: If the standby current value is less than the first standard current, the voltage value of the adjustable voltage and current device is calculated by dividing the voltage value of the adjustable voltage and current device by the first preset current value of the first resistance value; and when the first preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=3; when the first preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=Vε / R1+3; If the standby current value is greater than or equal to the first standard current and less than the second standard current, the voltage value of the adjustable voltage and current meter is divided by the second preset current value of the second resistance value; and when the second preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current meter is: Iε=5+IN / 30; when the second preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current meter is: Iε=Vε / R1+IN / 15; If the standby current value is greater than or equal to the second standard current and less than the third standard current, the voltage value of the adjustable voltage and current device is calculated by dividing the third preset current value of the third resistance value; and when the third preset current value is less than or equal to the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=7+IN / 30; when the third preset current value is greater than the target value, the calculation formula of the current value of the adjustable voltage and current device is: Iε=Vε / R2+IN / 30; If the standby current value is greater than or equal to the third standard current, the current value of the adjustable voltage and current device is calculated as follows: Iε=8+IN / 50; Wherein, Iε is the current value of the adjustable voltage and current device, Vε is the voltage value of the adjustable voltage and current device, IN is the standby current value, R1 is the first resistance value, and R2 is the second resistance value.

8. The control method based on the variable current discharge state of the iron-lithium battery according to any one of claims 1 to 7, characterized in that: Adjusting the first positive switch, the second positive switch, the first negative switch, the second negative switch and N+1 array switches of the adjustable voltage and current device to terminate the connection relationship between the adjustable voltage and current device and the nth lithium battery cell, including: If the serial number of the nth lithium battery cell is an odd number, the 2n-1th array switch and the 2nth array switch, as well as the first positive switch and the second negative switch are turned on to detect whether there is voltage between the first double line and the second double line. If so, a wiring error is reported. If not, the first positive switch and the second negative switch are kept turned on to terminate the connection between the adjustable voltage and current device and the nth lithium battery cell. If the serial number of the nth lithium battery cell is an even number, the 2nth array switch and the 2n+1th array switch, as well as the second positive switch and the first negative switch are turned on to detect whether there is voltage between the first double line and the second double line. If so, a wiring error is reported; if not, the second positive switch and the first negative switch are kept open to terminate the connection between the adjustable voltage and current meter and the nth lithium battery cell.

9. A control device based on the variable current discharge state of an iron-lithium battery, characterized in that: A control processor applied to a lithium iron battery control device, wherein the lithium iron battery control device also includes a lithium battery cell terminal voltage data acquisition module, a lithium iron battery current acquisition module, a switch array and an adjustable voltage and current device; the control processor executes a control method based on the lithium iron battery variable current discharge state as described in any one of claims 1 to 8.

10. A base station power supply system, characterized in that: Including base station power supply device and iron-lithium battery control device; The base station power supply device is connected to both ends of the power load, including a communication power supply and an iron-lithium battery, wherein the iron-lithium battery includes N lithium cells connected in series; The iron-lithium battery control device and the iron-lithium battery are both connected to the two ends of the communication power supply, the iron-lithium battery serves as a backup power supply for the communication power supply, the communication power supply and the iron-lithium battery both supply power to the communication load, and the communication power supply also supplies power to the iron-lithium battery control device; The control processor of the iron-lithium battery control device executes the control method based on the variable current discharge state of the iron-lithium battery as described in any one of claims 1 to 8.

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