Battery discharge circuit, circuit control method, and battery discharge device

Abstract

The application discloses a battery discharge circuit, a circuit control method and a battery discharge device. The battery discharge circuit comprises a resistance configuration branch, a current sampling branch, a switch branch, a signal amplification branch and a controller. The resistance configuration branch is connected between the battery and the switch branch, and is connected with the controller. The resistance configuration branch is configured as a first preset resistance. The current sampling branch is connected between the battery and the switch branch, and outputs a sampling signal based on the discharge current of the battery. The controller is connected with the signal amplification branch, and outputs a voltage signal corresponding to the target discharge current of the battery. The signal amplification branch is connected between the switch branch and the switch branch, and outputs an adjustment signal based on the sampling signal and the voltage signal. The switch branch adjusts the conduction degree of the switch branch based on the adjustment signal. The battery is discharged through the first preset resistance and the switch branch. In this way, the cost of battery discharge can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuit, in particular to a battery discharge circuit, a circuit control method and a battery discharge device. BACKGROUND

[0002] With the wider application of electric vehicles, the demand for repairing batteries used to power electric vehicles is also increasing. During the transportation of battery repair, the battery is required to be kept at a low power level to ensure safety. Therefore, based on the different power levels of the battery when it needs to be repaired, a corresponding discharge device needs to be designed to discharge the battery to keep it at a low power level.

[0003] At present, the commonly used mode is to feed back the battery power to the power grid to realize the discharge of the battery. However, this mode requires a high cost. SUMMARY

[0004] The present application aims to provide a battery discharge circuit, a circuit control method and a battery discharge device, which can reduce the cost of battery discharge.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a battery discharge circuit, comprising:

[0006] a resistance configuration branch, a current sampling branch, a switch branch, a signal amplification branch and a controller;

[0007] The first end of the resistance configuration branch is connected with the first end of the battery, the second end of the resistance configuration branch is connected with the first end of the switch branch, the first end of the current sampling branch is connected with the second end of the battery, the second end of the current sampling branch is connected with the second end of the switch branch and the second end of the signal amplification branch respectively, the first end of the signal amplification branch and the third end of the resistance configuration branch are connected with the controller, and the third end of the signal amplification branch is connected with the third end of the switch branch.

[0008] The resistance configuration branch is controlled by the controller and is configured as a first preset resistance.

[0009] The current sampling branch is used for sampling the discharge current of the battery and outputting a sampling signal.

[0010] The controller is used for outputting a voltage signal corresponding to the target discharge current of the battery.

[0011] The signal amplification branch is used for receiving the sampling signal and the voltage signal and outputting an adjustment signal.

[0012] The switch branch is used for receiving the adjustment signal and adjusting the conduction degree of the switch branch based on the adjustment signal.

[0013] The battery is discharged through the first preset resistance and the switch branch, and a discharge current of the battery is positively correlated with a conduction degree of the switch branch.

[0014] In an alternative way, the resistance configuration branch includes N resistance units and a line connection switching branch, any resistance unit of the N resistance units includes at least one resistance, and N is an integer greater than or equal to 1;

[0015] The line connection switching branch is connected with the N resistance units, the controller, the first end of the battery and the first end of the switch branch respectively;

[0016] The line connection switching branch is controlled by the controller, and the line connection switching branch is used to switch a connection relationship between different resistance units of the N resistance units and generate the first preset resistance.

[0017] In an alternative way, the N resistance units include a first resistance unit and a second resistance unit, and the line connection switching branch includes a first switch, a second switch and a third switch;

[0018] The first end of the first resistance unit is connected with the first end of the first switch and the first end of the battery respectively, the second end of the first switch is connected with the first end of the second resistance unit and the first end of the second switch respectively, the second end of the second switch is connected with the second end of the first resistance unit and the first end of the third switch respectively, the second end of the third switch is connected with the second end of the second resistance unit and the first end of the switch branch respectively, and the first switch, the second switch and the third switch are further connected with the controller;

[0019] The controller switches a connection relationship between the first resistance unit and the second resistance unit by controlling conduction and turn-off of the first switch, the second switch and the third switch.

[0020] In an alternative way, the first resistance unit includes a first resistance, a second resistance and a fourth switch, and the second resistance unit includes a third resistance, a fourth resistance and a fifth switch;

[0021] The first resistor and the second resistor are connected in series, the second resistor and the fourth switch are connected in parallel, a non-series connection end of the first resistor is a first end of the first resistor unit, a non-series connection end of the second resistor is a second end of the first resistor unit, the third resistor and the fourth resistor are connected in series, the fourth resistor and the fifth switch are connected in parallel, a non-series connection end of the third resistor is a first end of the second resistor unit, and a non-series connection end of the fourth resistor is a second end of the second resistor unit.

[0022] In an optional mode, the current sampling branch includes a first sampling resistor.

[0023] A first end of the first sampling resistor is connected with the second end of the battery, and a second end of the first sampling resistor is connected with the second end of the switch branch.

[0024] In an optional mode, the switch branch includes a first switch tube.

[0025] A first end of the first switch tube is connected with a third end of the signal amplification branch, a second end of the first switch tube is connected with the current sampling branch, and a third end of the first switch tube is connected with a second end of the resistance configuration branch.

[0026] In an optional mode, the signal amplification branch includes a first amplification unit and a second amplification unit.

[0027] A first end of the first amplification unit is connected with the second end of the switch branch, a second end of the first amplification unit is connected with a first end of the second amplification unit, a second end of the second amplification unit is connected with the controller, and a third end of the second amplification unit is connected with a third end of the switch branch.

[0028] The first amplification unit is configured to receive the sampling signal and amplify the sampling signal.

[0029] The second amplification unit is configured to receive the voltage signal and the amplified sampling signal and output the adjustment signal.

[0030] In an optional mode, the first amplification unit includes a first operational amplifier, a fifth resistor and a sixth resistor.

[0031] A first input end of the first operational amplifier is connected with the second end of the switch branch, second input ends of the first operational amplifier are connected with a first end of the fifth resistor and a first end of the sixth resistor, an output end of the first operational amplifier is connected with a second end of the fifth resistor and a first end of the second amplification unit, and a second end of the sixth resistor is grounded.

[0032] In an alternative mode, the second amplification unit comprises a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, a third capacitor and a second operational amplifier;

[0033] The first end of the seventh resistor is connected to the second end of the first amplification unit, the second end of the seventh resistor is connected to the first end of the eighth resistor, the first end of the first capacitor, the first end of the second capacitor and the second input end of the second operational amplifier respectively, the second end of the eighth resistor is connected to the first end of the ninth resistor and the controller respectively, the second end of the ninth resistor is connected to the second end of the first capacitor, the first end of the third capacitor and the first input end of the second operational amplifier respectively, the output end of the second operational amplifier is connected to the second end of the second capacitor and the third end of the switch branch respectively, and the second end of the third capacitor is grounded.

[0034] In a second aspect, the application provides a circuit control method for controlling the battery discharge circuit as described above, the method comprising:

[0035] Switching the connection relationship between different resistance units of the N resistance units of the resistance configuration branch to obtain M connection states of the N resistance units, wherein M and N are integers greater than or equal to 1;

[0036] For each of the M connection states, the number of effective resistances in the N resistance units is changed, the resistance set in each connection state is determined, and M resistance sets in the M connection states are obtained;

[0037] Based on a preset target set, a first resistance set matching the target set is determined from the M resistance sets;

[0038] A first preset resistance is obtained from the first resistance set, and the battery is discharged through the first preset resistance.

[0039] In an alternative mode, the determination of the first resistance set matching the target set from the M resistance sets based on the target set comprises:

[0040] The intersection of the target set and each of the M resistance sets is obtained;

[0041] The resistance coverage is determined according to the intersection and the target set;

[0042] For each of the M resistance sets, the maximum discharge current of the battery is obtained, the target discharge current of the battery is obtained, and the current coverage is determined based on the ratio of the maximum discharge current to the target discharge current;

[0043] determining a matching rate of each of the M sets of resistors according to the resistance coverage and the current coverage of each of the M sets of resistors, and obtaining M matching rates under the M sets of resistors;

[0044] determining a maximum value in the M matching rates, and determining the set of resistors corresponding to the maximum value as the first set of resistors.

[0045] In an optional manner, the obtaining of the first preset resistor in the first set of resistors comprises:

[0046] determining a target resistor based on a ratio of the voltage of the battery to the target discharging current;

[0047] if an absolute value of a difference between a resistance value of the first equivalent resistor and a resistance value of the target resistor in the first set of resistors is less than a first preset difference value, the first equivalent resistor is taken as the first preset resistor.

[0048] In an optional manner, the method further comprises:

[0049] if the first equivalent resistor does not exist in the first set of resistors, and there are J resistors in the first set of resistors with resistance values less than the resistance value of the target resistor, a second equivalent resistor is obtained, wherein the second equivalent resistor is a resistor with the largest resistance value in the J resistors, and J is an integer greater than or equal to 1;

[0050] determining the power on the switch branch based on the current discharging current of the battery, the voltage of the battery, and the second equivalent resistor;

[0051] if the power is less than or equal to the rated power of the switch branch, the second equivalent resistor is taken as the first preset resistor.

[0052] In an optional manner, the method further comprises:

[0053] if the first equivalent resistor and the second equivalent resistor do not exist in the first set of resistors, and there are L resistors in the first set of resistors with resistance values greater than the resistance value of the target resistor, a third equivalent resistor is obtained and taken as the first preset resistor, wherein the third equivalent resistor is a resistor with the smallest resistance value in the L resistors, and L is an integer greater than or equal to 1.

[0054] In an optional manner, after the obtaining of the first preset resistor in the first set of resistors, the method further comprises:

[0055] determining a first difference value based on the voltage of the battery, the first preset resistor, and the rated power of the switch branch.

[0056] If the first difference is less than or equal to a preset threshold, a maximum discharge current of the battery is determined based on a ratio of the voltage of the battery to a resistance value of the first preset resistor.

[0057] If the target discharge current of the battery is less than the maximum discharge current, an actual discharge current of the battery is controlled to be the target discharge current.

[0058] If the target discharge current is greater than or equal to the maximum discharge current, the actual discharge current of the battery is controlled to be the maximum discharge current.

[0059] In an optional manner, the method further comprises:

[0060] If the first difference is greater than the preset threshold, two discharge currents of the battery are determined based on the current discharge current of the battery, the voltage of the battery, the resistance value of the first preset resistor and a rated power of the switch branch.

[0061] If the target discharge current is less than or equal to a first discharge current of the two discharge currents, or the target discharge current is greater than or equal to a second discharge current of the two discharge currents, the actual discharge current of the battery is controlled to be the target discharge current, wherein the first discharge current is less than the second discharge current.

[0062] If the target discharge current is greater than the first discharge current and less than the second discharge current, the actual discharge current of the battery is controlled to be the first discharge current.

[0063] In a third aspect, the present application provides a controller, comprising:

[0064] At least one processor and a memory connected to the at least one processor in communication, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method as described above.

[0065] In a fourth aspect, the present application provides a battery discharge device, comprising a battery discharge circuit as described above, and / or a controller as described above.

[0066] The application has the following beneficial effects: the battery discharge circuit provided by the application comprises a resistance configuration branch, a current sampling branch, a switch branch, a signal amplification branch and a controller. When it is necessary to control the battery discharge, on the one hand, the controller controls the resistance configuration branch, and the resistance configuration branch can be configured as a first preset resistance, and the battery discharges through the first preset resistance; on the other hand, the battery also discharges through the switch branch. Thus, the process of battery discharge is realized, and the circuit structure is relatively simple, and the cost is relatively low compared with the mode of feeding back the electric energy of the battery to the power grid in the related art. Secondly, the current sampling branch outputs a sampling signal based on the discharge current of the battery at the second end of the switch branch. The controller outputs a voltage signal corresponding to the target discharge current of the battery. The signal amplification branch outputs an adjustment signal to the third end of the switch branch based on the sampling signal and the voltage signal. Then, the switch branch can adjust the conduction degree of the switch branch based on the adjustment signal, so as to adjust the discharge current of the battery, which is beneficial to maintaining the rapid and stable discharge of the battery and improving the efficiency and stability of the battery discharge circuit. BRIEF DESCRIPTION OF DRAWINGS

[0067] One or more embodiments are illustrated by way of example in the figures that form a part of this patent document, and which demonstrate specific illustrative examples of embodiments of the application. In the drawings: like reference numerals demonstrate like elements except when context dictates otherwise, the figures shown in the drawings are not necessarily to scale, and elements having the same reference number designations in different figures represent like elements having the same or similar function.

[0068] Figure 1 A structural schematic diagram of a battery discharge circuit provided by an embodiment of the application;

[0069] Figure 2 A structural schematic diagram of a battery discharge circuit provided by another embodiment of the application;

[0070] Figure 3 A structural schematic diagram of a battery discharge circuit provided by still another embodiment of the application;

[0071] Figure 4 A structural schematic diagram of a battery discharge circuit provided by still another embodiment of the application;

[0072] Figure 5 A structural schematic diagram of a battery discharge circuit provided by still another embodiment of the application;

[0073] Figure 6 A structural schematic diagram of a battery discharge circuit provided by still another embodiment of the application;

[0074] Figure 7 A circuit structure schematic diagram of a signal amplification branch provided by an embodiment of the application;

[0075] Figure 8 A flowchart of a circuit control method provided by an embodiment of the application;

[0076] Figure 9 A schematic diagram of an embodiment of step 803 shown in Figure 8 FIG. 4 is a schematic diagram of an embodiment of step 804 shown in

[0077] Figure 10 A schematic diagram of an embodiment of step 804 shown in Figure 8 FIG. 4 is a schematic diagram of an embodiment of step 804 shown in

[0078] Figure 11 A schematic diagram of an embodiment after step 804 shown in Figure 8 FIG. 4 is a schematic diagram of an embodiment after step 804 shown in

[0079] Figure 12 A schematic diagram of a first difference provided by an embodiment of the present application.

[0080] Figure 13 A schematic diagram of a structure of a controller provided by an embodiment of the present application. DETAILED DESCRIPTION

[0081] In order to make the objectives, technical solutions and advantages of embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions of the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0082] Please refer to Figure 1 , Figure 1 A schematic diagram of a structure of a battery discharge circuit provided by an embodiment of the present application. As shown in Figure 1 the battery discharge circuit 100 includes a resistance configuration branch 10, a current sampling branch 20, a switch branch 30, a signal amplification branch 40 and a controller 50.

[0083] The first end of the resistance configuration branch 10 is connected with the first end of the battery 200, the second end of the resistance configuration branch 10 is connected with the first end of the switch branch 30, and the third end of the resistance configuration branch 10 and the first end of the signal amplification branch 40 are both connected with the controller 50. The first end of the current sampling branch 20 is connected with the second end of the battery 200, and the second end of the current sampling branch 20 is connected with the second end of the switch branch 30 and the second end of the signal amplification branch 40 respectively. The third end of the signal amplification branch 40 is connected with the third end of the switch branch 30.

[0084] Specifically, the resistance configuration branch 10 is controlled by the controller 50 and is configured as a first preset resistance. The current sampling branch 20 is configured to sample the discharge current of the battery 200 and output a sampling signal based on the discharge current of the battery 200 at the second end of the switch branch 30. The controller 50 is configured to output a voltage signal corresponding to a target discharge current of the battery 200 to the signal amplification branch 40. The signal amplification branch 40 is configured to receive the sampling signal and the voltage signal and output an adjustment signal to the third end of the switch branch 30 based on the sampling signal and the voltage signal. The switch branch 30 is configured to receive the adjustment signal and adjust the conduction degree of the switch branch 30 based on the adjustment signal. The equivalent resistance of the switch branch 30 and the conduction degree of the switch branch 30 present a negative correlation, that is, the equivalent resistance of the switch branch 30 decreases as the conduction degree of the switch branch 30 deepens. The battery is discharged through the first preset resistance and the switch branch 30. The discharge current of the battery 200 and the conduction degree of the switch branch 30 present a positive correlation, that is, the discharge current of the battery 200 increases as the conduction degree of the switch branch 30 deepens.

[0085] In actual application, when it is needed to control the battery 200 to discharge, on the one hand, the controller 50 controls the resistance configuration branch 10 and configures the resistance configuration branch 10 as a first preset resistance. The battery 200 can be discharged through the first preset resistance. On the other hand, the battery 200 is also discharged through the switch branch 30. Through the above-mentioned manner, the process of consuming the discharge electric energy of the battery 200 through the first preset resistance and the switch branch 30 is realized, that is, the process of discharging the battery 200. Moreover, the process is realized by using a relatively simple circuit structure, and the cost required is relatively low compared with the mode of feeding back the electric energy of the battery 200 to the power grid in the related art.

[0086] Meanwhile, by adjusting the conduction degree of the switch branch 30, the discharge current of the battery 200 can also be adjusted, which is conducive to maintaining the fast and stable discharge of the battery 200 and improving the working efficiency and stability of the battery discharge circuit 100. Specifically, the current sampling branch 20 outputs a sampling signal to the signal amplification branch 40 based on the discharge current of the battery 200. The controller 50 outputs a voltage signal corresponding to a target discharge current of the battery 200. The target discharge current is a preset discharge current. The signal amplification branch 40 outputs an adjustment signal to the switch branch 30 based on the sampling signal and the voltage signal, so as to adjust the conduction degree of the switch branch 30 and further adjust the equivalent resistance of the switch branch 30 when the switch branch 30 is conducting. Since the switch branch 30 can be equivalent to a resistance with different resistance values at different conduction degrees, according to Ohm's law, when the resistance value of the switch branch 30 changes, the current flowing through the switch branch 30 also changes, and the current flowing through the switch branch 30 is also the discharge current of the battery 200. In summary, adjusting the conduction degree of the switch branch 30 can adjust the discharge current of the battery 200.

[0087] In an embodiment, as shown in Figure 2 The resistance configuration branch 10 includes N resistance units 12 and a line connection switching branch 11. Any of the N resistance units 12 includes at least one resistor, and N is an integer greater than or equal to 1. The N resistance units 12 include a first resistance unit Ra1, a second resistance unit Ra2, and an Nth resistance unit RaN.

[0088] The line connection switching branch 11 is connected to the N resistance units 12, the controller 50, the first end of the battery 200, and the first end of the switch branch 30, respectively. The line connection switching branch 11 is controlled by the controller 50. The line connection switching branch 11 is used to switch the connection relationship between different resistance units of the N resistance units 12 and generate a first preset resistance.

[0089] Specifically, the controller 50 can switch the connection relationship between the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN by controlling the line connection switching branch 11. When the connection relationship between the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN is determined, the entire first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN serve as an equivalent resistance. When the connection relationship between the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN changes, the equivalent resistance corresponding to the entire first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN also changes. Thus, by switching the connection relationship between the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN, one or more equivalent resistances can be obtained. Among these equivalent resistances, the first preset resistance can be determined. For example, the controller 50 controls the line connection switching branch 11 to connect the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN in series, and then the first preset resistance can be the equivalent resistance of the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN connected in series.

[0090] In this embodiment, by switching the connection relationship between the first resistance unit Ra1, the second resistance unit Ra2, and the Nth resistance unit RaN, different first preset resistances can be obtained to meet the required resistance in different application scenarios, which is beneficial to improve the practicality of the resistance configuration branch 10.

[0091] In an embodiment, as shown in Figure 3 The N resistance units 12 include the first resistance unit Ra1 and the second resistance unit Ra2, and the line connection switching branch 11 includes a first switch K1, a second switch K2, and a third switch K3.

[0092] The first end of the first resistance unit Ra1 is connected with the first end of the first switch K1 and the first end of the battery 200 respectively, the second end of the first switch K1 is connected with the first end of the second resistance unit Ra2 and the first end of the second switch K2 respectively, the second end of the second switch K2 is connected with the first end of the first resistance unit Ra1 and the first end of the third switch K3 respectively, the second end of the third switch K3 is connected with the second end of the second resistance unit Ra2 and the first end of the switch branch 30, and the first switch K1, the second switch K2 and the third switch K3 are also connected with the controller 50.

[0093] Specifically, the controller 50 switches the connection relationship between the first resistance unit Ra1 and the second resistance unit Ra2 by controlling the conduction and the turn-off of the first switch K1, the second switch K2 and the third switch K3, and the first preset resistance with different resistance values can be obtained. For example, the controller 50 controls the first switch K1 and the third switch K3 to be turned on, and controls the second switch K2 to be turned off, so that the first resistance unit Ra1 and the second resistance unit Ra2 are connected in parallel, and the first preset resistance is the equivalent resistance after the first resistance unit Ra1 and the second resistance unit Ra2 are connected in parallel. For another example, the controller 50 controls the second switch K2 to be turned on, and controls the first switch K1 and the third switch K3 to be turned off, so that the first resistance unit Ra1 and the second resistance unit Ra2 are connected in series, and the first preset resistance is the equivalent resistance after the first resistance unit Ra1 and the second resistance unit Ra2 are connected in series.

[0094] It can be understood that in this embodiment, N=2 is taken as an example, and in other embodiments, N can also be selected in other ways, and the switches in the line connection switching branch 11 also need to be adjusted accordingly. The specific adjustment mode can be referred to the mode shown in Figure 3 which is within the scope of easy understanding of those skilled in the art, and will not be described here.

[0095] In an embodiment, as Figure 4 indicated, the first resistance unit Ra1 includes a first resistance R1, a second resistance R2 and a fourth switch K4, and the second resistance unit Ra2 includes a third resistance R3, a fourth resistance R4 and a fifth switch K5.

[0096] The first resistance R1 and the second resistance R2 are connected in series, the second resistance R2 and the fourth switch K4 are connected in parallel, the non-series connection end of the first resistance R1 is the first end of the first resistance unit Ra1, the non-series connection end of the second resistance R2 is the second end of the first resistance unit Ra1, the third resistance R3 and the fourth resistance R4 are connected in series, the fourth resistance R4 and the fifth switch K5 are connected in parallel, the non-series connection end of the third resistance R3 is the first end of the second resistance unit Ra2, and the non-series connection end of the fourth resistance R4 is the second end of the second resistance unit Ra2.

[0097] In this embodiment, the first resistance unit Ra1 and the second resistance unit Ra2 each include two resistors as an example, and in other embodiments, each resistance unit can include more or less resistors, and the first resistance unit Ra1 and the second resistance unit Ra2 can be the same or different.

[0098] In this embodiment, when the fourth switch K4 is turned off, the resistance of the first resistor R1 and the second resistor R2 in series is the equivalent resistance of the first resistance unit Ra1, at this time, the effective resistance is the first resistor R1 and the second resistor R2; when the fourth switch K4 is turned on, the second resistor R2 is short-circuited, and the first resistor R1 is the equivalent resistance of the first resistance unit Ra1, at this time, the effective resistance is the first resistor R1. Similarly, when the fifth switch K5 is turned off, the resistance of the third resistor R3 and the fourth resistor R4 in series is the equivalent resistance of the second resistance unit Ra2, at this time, the effective resistance is the third resistor R3 and the fourth resistor R4; when the fifth switch K5 is turned on, the fourth resistor R4 is short-circuited, and the third resistor R3 is the equivalent resistance of the second resistance unit Ra2, at this time, the effective resistance is the third resistor R3.

[0099] Therefore, by controlling the conduction or turn-off of the fourth switch K4 and the fifth switch K5, the equivalent resistance of the first resistance unit Ra1 or the second resistance unit Ra2 can be changed, and more first preset resistors with different resistance values can be obtained, the application scenarios that can be met are increased, and the practicability of the battery discharge circuit is further improved.

[0100] In an embodiment, please refer to Figure 1 Referring to Figure 5 As shown in Figure 5 , the current sampling branch 20 includes a first sampling resistor RC1.

[0101] Specifically, the first end of the first sampling resistor RC1 is connected with the second end of the battery 200, and the second end of the first sampling resistor RC1 is connected with the second end of the switch branch 30. The first sampling resistor RC1 is used to convert the current output by the battery 200 into a voltage and input to the signal amplification branch 40.

[0102] In the first embodiment, as shown in Figure 5 , the switch branch 30 includes a first switch tube Q1.

[0103] Among them, the first end of the first switch tube Q1 is connected with the third end of the signal amplification branch 40 (i.e. one end of the signal amplification branch 40 outputting the adjustment signal), the second end of the first switch tube Q1 is connected with the second end of the current sampling branch 20, and the third end of the first switch tube Q1 is connected with the second end of the resistance configuration branch 10.

[0104] In some implementations, the first switching transistor Q1 may be an IGBT or a MOSFET, and this application does not impose specific limitations on this. Taking an IGBT as an example, the gate of the IGBT is the first terminal of the first switching transistor Q1, the emitter is the second terminal of the first switching transistor Q1, and the collector is the third terminal of the first switching transistor Q1.

[0105] Taking the first switching transistor Q1 as an IGBT switch as an example. In this embodiment, when the voltage of the adjustment signal output from the signal amplification branch 40 causes the IGBT switch to operate in the adjustable resistance region, as the voltage of the adjustment signal increases, the conduction degree of the IGBT switch increases, and the resistance value of the IGBT switch decreases; as the voltage of the adjustment signal decreases, the conduction degree of the IGBT switch decreases, and the resistance value of the IGBT switch increases. When the voltage of the adjustment signal increases to the point that the IGBT switch operates in the saturation region, the IGBT switch only functions as a switch. The conduction degree of the IGBT switch corresponds to the conduction degree of the switching branch 30.

[0106] In other embodiments, to meet the higher discharge power requirements of battery 200, multiple switching branches, multiple current sampling branches, and multiple signal amplification branches can be provided. In this configuration, one switching branch is connected to one current sampling branch and one signal amplification branch. For example, as... Figure 6 As shown, Figure 6 The diagram illustrates two switching branches, two current sampling branches, and two signal amplification branches. The connections between the branches can be found in [reference needed]. Figure 6 This will not be elaborated further here. In this embodiment, both switch branches 30 can consume the electrical energy discharged by the battery, and the discharge current of the battery 200 is the sum of the currents flowing through the two switch branches 30.

[0107] In one embodiment, such as Figure 7 As shown, the signal amplification branch 40 includes a first amplification unit 41 and a second amplification unit 42.

[0108] Specifically, the first terminal of the first amplification unit 41 is connected to the second terminal of the switching branch 30 and the second terminal of the current sampling branch 20, and the second terminal of the first amplification unit 41 is connected to the first terminal of the second amplification unit 42. The third terminal of the second amplification unit 42 is connected to the third terminal of the switching branch 30. The second terminal of the second amplification unit 42 is connected to the controller 50.

[0109] Specifically, the first amplification unit 41 is configured to receive the sampling signal and amplify the sampling signal and then input the amplified sampling signal to the second amplification unit 42. In actual application, the current sampling branch 20 usually adopts a sampling resistor with a small resistance value to convert the current into a voltage. Therefore, the voltage converted by the current sampling branch 20 has a small value. In order to prevent abnormal situations such as signal mis-detection or signal detection error caused by the small value of the voltage, the value of the voltage needs to be amplified before subsequent operations, which is beneficial to improve the stability of the circuit operation.

[0110] The second amplification unit 42 is configured to output an adjustment signal based on the voltage signal output by the controller 50 and the amplified sampling signal. The controller 50 outputs a voltage signal corresponding to the target discharge current, i.e., the voltage signal as a reference signal. The reference signal is compared with the actual sampling signal and amplified, and an adjustment signal is output based on the comparison result. The adjustment signal is used to adjust the conduction degree of the switching branch 30 to adjust the discharge current of the battery 200, so as to realize that the discharge current of the battery 200 finally approaches or equals the target discharge current.

[0111] In an embodiment, the first amplification unit 41 includes a first operational amplifier U1, a fifth resistor R5, and a sixth resistor R6.

[0112] The first input terminal of the first operational amplifier U1 is connected to the second end of the switching branch 30, the second input terminal of the first operational amplifier U1 is connected to the first end of the fifth resistor R5 and the first end of the sixth resistor R6, the output terminal of the first operational amplifier U1 is connected to the second end of the fifth resistor R5 and the first end of the second amplification unit 42, and the second end of the sixth resistor R6 is grounded GND. In this embodiment, the first input terminal of the first operational amplifier U1 is taken as the non-inverting input terminal, and the second input terminal is taken as the inverting input terminal.

[0113] Specifically, the first amplification unit 41 composed of the first operational amplifier U1, the fifth resistor R5, and the sixth resistor R6 can amplify the sampling signal on the current sampling branch 20, and the amplification multiple is determined by the resistance values of the fifth resistor R5 and the sixth resistor R6.

[0114] In an embodiment, the second amplification unit 42 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a second operational amplifier U2.

[0115] The first end of the seventh resistor R7 is connected with the second end of the first amplification unit 41, the second end of the seventh resistor R7 is connected with the first end of the eighth resistor R8, the first end of the first capacitor C1, the first end of the second capacitor C2 and the second input end of the second operational amplifier U2 respectively, the second end of the eighth resistor R8 is connected with the first end of the ninth resistor R9 and the controller 50 respectively, the second end of the ninth resistor R9 is connected with the second end of the first capacitor C1, the first end of the third capacitor C3 and the first input end of the second operational amplifier U2 respectively, the output end of the second operational amplifier U2 is connected with the second end of the second capacitor C2 and the third end of the switch branch 30 respectively, and the second end of the third capacitor C3 is grounded GND. In this embodiment, the first input end of the second operational amplifier U2 is taken as the in-phase input end, and the second input end is taken as the reverse input end.

[0116] Specifically, when there is a difference between the amplified sampling signal and the voltage signal output by the controller 50, that is, the voltages of the first input end and the second input end of the second operational amplifier U2 are not equal, the adjustment signal output by the second operational amplifier U2 can act on the second input end of the second operational amplifier U2 through the feedback of the second capacitor C2 to automatically adjust the voltages of the first input end and the second input end of the second operational amplifier U2 to be equal. That is, the greater the difference between the amplified sampling signal and the voltage signal, the greater the voltage of the output adjustment signal, which can adjust the voltages of the first input end and the second input end of the second operational amplifier U2 to be equal. In turn, the greater the voltage value of the adjustment signal, the greater the conduction degree of the switch branch 30, the smaller the resistance value of the switch branch 30, and the greater the discharge current of the battery 200, so as to reduce the difference between the amplified sampling signal and the voltage signal, that is, to reduce the voltage difference between the first input end and the second input end of the second operational amplifier U2. The above process is continuously and automatically repeated until the voltages of the first input end and the second input end of the second operational amplifier U2 are equal. Through the above manner, the process of automatically adjusting the switch branch 30 based on the voltage signal output by the controller 50 can be realized, so as to realize the discharge current of the battery 200 as the target discharge current corresponding to the voltage signal.

[0117] Please refer to Figure 8 , Figure 8 The flow chart of the circuit control method provided by the embodiment of the present application. The circuit control method is used for controlling the battery discharge circuit in any embodiment of the present application. As shown in Figure 8 , the circuit control method comprises:

[0118] Step 801: switching the connection relationship between different resistance units of the N resistance units of the resistance configuration branch to obtain M connection states of the N resistance units.

[0119] Wherein, M and N are integers greater than or equal to 1. For example Figure 3The structure shown is an example. In this case, N = 2. As can be seen from the above embodiment, if the first switch K1 and the third switch K3 in the control circuit connection switching branch are on, and the second switch K2 is off, then the connection relationship between the first resistor unit Ra1 and the second resistor unit Ra2 is parallel. The parallel connection of the first resistor unit Ra1 and the second resistor unit Ra2 is the first connection state.

[0120] If the first switch K1 and the third switch K3 in the control circuit connection switching branch are disconnected, and the second switch K2 is on, then the connection relationship between the first resistor unit Ra1 and the second resistor unit Ra2 is series connection. The series connection of the first resistor unit Ra1 and the second resistor unit Ra2 is the second connection state. In this case, M = 2.

[0121] Understandably, in Figure 3 In the structure shown, only N=2 is used as an example. When N is other values, the number of connection states that can be obtained will also be different, which is easily understood by those skilled in the art and will not be elaborated here. Secondly, in this embodiment, only one embodiment of M=N=2 is shown as an example. In other embodiments, M can be greater than N or less than N, and can be set according to the actual application. This application embodiment does not impose specific limitations on this.

[0122] Step 802: For each of the M connection states, change the number of effective resistors in the N resistor units to determine the resistor set for each connection state, and obtain the M resistor sets for the M connection states.

[0123] Specifically, for each of the M connection states, by changing the number of effective resistors in the N resistor units, at least one equivalent resistor can be obtained in each connection state. The set of all equivalent resistors obtained in each connection state is the resistance set for that connection state. Since there are a total of M connection states, a total of M resistance sets can be obtained.

[0124] by Figure 4 Taking the structure shown as an example, as can be seen from the above, N = M = 2. There are a total of two connection states. The first connection state is the first resistor unit Ra1 and the second resistor unit Ra2 connected in parallel; the second connection state is the first resistor unit Ra1 and the second resistor unit Ra2 connected in series.

[0125] For the first connection state, when both the fourth switch K4 and the fifth switch K5 are on, the number of effective resistors is 2, which are the first resistor R1 and the third resistor R3. At this time, the equivalent resistance is the resistance of the first resistor R1 and the third resistor R3 connected in parallel, denoted as the equivalent resistance Re1.

[0126] When the fourth switch K4 is turned on and the fifth switch K5 is turned off, the number of effective resistors is 3, and the effective resistors are the first resistor R1, the third resistor R3 and the fourth resistor R4. At this time, the equivalent resistance is the resistance of the circuit obtained by connecting the third resistor R3 and the fourth resistor R4 in series and connecting the first resistor R1 in parallel with the circuit. Denoted as equivalent resistance Re2.

[0127] When the fourth switch K4 is turned off and the fifth switch K5 is turned on, the number of effective resistors is 3, and the effective resistors are the first resistor R1, the second resistor R2 and the third resistor R3. At this time, the equivalent resistance is the resistance of the circuit obtained by connecting the first resistor R1 and the second resistor R2 in series and connecting the third resistor R3 in parallel with the circuit. Denoted as equivalent resistance Re3.

[0128] When the fourth switch K4 and the fifth switch K5 are both turned off, the number of effective resistors is 4, and the effective resistors are the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4. At this time, the equivalent resistance is the resistance of the circuit obtained by connecting the first resistor R1 and the second resistor R2 in series and connecting the third resistor R3 and the fourth resistor R4 in series, and connecting the two circuits in parallel. Denoted as equivalent resistance Re4.

[0129] It can be seen that in the first connection state, a total of 4 equivalent resistances can be obtained. The resistance set in the first connection state includes the 4 equivalent resistances Re1, Re2, Re3 and Re4.

[0130] For the second connection state, 4 equivalent resistances in the second connection state can be obtained based on the same way. It is within the scope of those skilled in the art to understand that it will not be described here.

[0131] In summary, in each of the M connection states, a resistance set can be determined. For example, in the above embodiment, a resistance set can be determined in the first connection state and the second connection state in the two states, and a total of two resistance sets are determined. Therefore, when there are a total of M connection states, M resistance sets can be obtained.

[0132] Step 803: determining a first resistance set matched with the target set from the M resistance sets based on the preset target set.

[0133] Specifically, the matching degrees of each resistance set in the M resistance sets and the target set are obtained, and the resistance set with the highest matching degree in the M resistance sets is taken as the first resistance set matched with the target set.

[0134] The target set can be set according to actual application conditions, and the embodiment of the present application does not make specific limitation on this. For example, the target set can be designed according to the ratio of the actual voltage of the battery to be discharged and the target discharge current required.

[0135] In an embodiment, as shown in Figure 9 The process of determining, in step 803, a first resistance set matching the target set from the M resistance sets based on the preset target set comprises the following steps:

[0136] Step 901: Obtain the intersection of the target set and each of the M resistance sets.

[0137] Specifically, the intersection of the target set and each of the M resistance sets can be obtained by the following formula:

[0138] rad(a) = rSet∩r(a)Set (1)

[0139] wherein rSet is the target set, r(a)Set is the a-th resistance set, rad(a) is the intersection of the target set and the a-th resistance set, and a is an integer ≤ M. Specifically, the first preset resistance set rSet includes at least one resistance, and the intersection of the target set and the a-th resistance set is the resistance with the same resistance value in the target set and the a-th resistance set. Assigning a to 1-M respectively and substituting into formula (1) in turn, the intersection of the target set and each of the M resistance sets can be obtained.

[0140] Step 902: Determine the resistance coverage according to the intersection and the target set.

[0141] In some embodiments, the resistance coverage can be obtained by the following formula:

[0142] rp(a) = (rad(a) max -rad(a) min ) / (r max -r min ) (2)

[0143] wherein rp(a) is the resistance coverage, rad(a) max is the maximum value in the intersection rad(a), rad(a) min is the minimum value in the intersection rad(a), r max is the maximum value in the target set rSet, and r min is the minimum value in the target set rSet. The numerator in formula (2) is the range of the intersection of the target set and the a-th resistance set, and the denominator in formula (2) is the range of the target set. The ratio of the above two ranges is the resistance coverage. Assigning a to 1-M respectively and substituting into formula (2) in turn, the resistance coverage of each of the M resistance sets can be obtained.

[0144] The resistance coverage is used to determine the matching degree of each of the M resistance sets with the target set. For example, in some embodiments, the target set includes a resistance range of 10 ohms to 90 ohms, and the intersection of the target set and the ath resistance set includes a resistance range of 20 ohms to 60 ohms, then the resistance coverage rp(a) of the ath resistance set is (90-10) / (60-20)=2.

[0145] Step 903: For each of the M resistance sets, obtain the maximum discharge current of the battery, and obtain the target discharge current of the battery, and determine the current coverage based on the ratio of the maximum discharge current and the target discharge current.

[0146] Specifically, the current coverage can be obtained by the following formula:

[0147] ip(a)=i(a) max / iSet(3)

[0148] Wherein, ip(a) is the current coverage, i(a) max is the maximum discharge current that can be obtained by using the ath resistance set when the battery is discharged, and iSet is the target discharge current of the battery. Assign a to 1-M respectively, and substitute into formula (3) in turn, and the current coverage of each of the M resistance sets can be obtained.

[0149] The current coverage is used to determine the matching degree of the maximum discharge current and the target discharge current.

[0150] Step 904: According to the resistance coverage and the current coverage of each of the M resistance sets, determine the matching rate of each of the M resistance sets, and obtain M matching rates under the M resistance sets.

[0151] Step 905: Determine the maximum value in the M matching rates, and determine the first resistance set corresponding to the maximum value.

[0152] Specifically, in an embodiment, the matching rate of the ath resistance set is determined by the following formula:

[0153] p(a)=X*rp(a)+Y*ip(a)(4)

[0154] Wherein, X and Y are coefficients, and X+Y=1.

[0155] In this embodiment, assign a to 1-M respectively, and substitute into formula (4) in turn, and the matching rate of each of the M resistance sets can be obtained, and a total of M matching rates can be obtained. This embodiment comprehensively considers the influence of the resistance coverage and the current coverage, and can obtain the resistance set with higher matching degree with the target set in actual application.

[0156] In some embodiments, the resistance coverage can be prioritized, and thus the proportion of the resistance coverage should be increased, in which X is greater than 0.5 and Y is less than 0.5. For example, X = 0.7 and Y = 0.3. Of course, in other embodiments, X and Y can also take other values, and the embodiments of the present application do not make specific limitations in this regard.

[0157] Then, the obtained M matching rates are compared in size, and the resistance set with the largest matching rate is the first resistance set. For example, in some embodiments, M = 3. That is, there are three resistance sets in total, the matching rate calculated by the first resistance set is P1, the matching rate calculated by the second resistance set is P2, and the matching rate calculated by the third resistance set is P3, and P1 < P2 < P3. Then, the third resistance set is taken as the first resistance set.

[0158] In Figure 9 In the embodiments shown, the matching rate of the existing resistance set with the target set is calculated, and the resistance set with the highest matching rate with the target set is used as the first resistance set actually used. On the one hand, even if different application scenarios need to set different target sets, the battery discharge circuit provided by the embodiments of the present application can determine the first resistance set corresponding to the target set, that is, the battery discharge circuit can be applied to various application scenarios without the need to replace components, and has high practicability. On the other hand, the resistance set with the largest matching rate is obtained in each resistance set, which helps to control the battery discharge current to be close to or equal to the required target discharge current, so as to keep the battery to discharge quickly and stably, thereby improving the efficiency and stability of the battery discharge circuit.

[0159] Step 804: obtaining a first preset resistance in the first resistance set.

[0160] Wherein, the battery discharges through the first preset resistance.

[0161] In an embodiment, as shown in Figure 10 The process of obtaining the first preset resistance in the first resistance set in step 804 includes the following steps:

[0162] Step 1001: determining a target resistance based on the ratio of the voltage of the battery to the target discharge current.

[0163] Step 1002: if the absolute value of the difference between the resistance value of the first equivalent resistance and the resistance value of the target resistance in the first resistance set is less than the first preset difference, taking the first equivalent resistance as the first preset resistance.

[0164] The first preset difference value can be set according to actual application, and embodiments of the present application do not make specific limitation on this. For example, in an embodiment, the first preset difference value is set to 0.1 ohm. If there is an equivalent resistance (i.e., the first equivalent resistance) in the first resistance set, the resistance value of which is 10 ohm, and the resistance value of the target resistance is 10 ohm, then the absolute value of the difference between the first equivalent resistance and the target resistance is 0, which is less than 0.1 ohm. At this time, the first equivalent resistance is used as the first preset resistance.

[0165] In another embodiment, the circuit control method further includes the following steps: if there is no first equivalent resistance in the first resistance set, and there are J resistances in the first resistance set, the resistance values of which are less than the resistance value of the target resistance, then a second equivalent resistance is obtained. The second equivalent resistance is the resistance with the largest resistance value among the J resistances, and J is an integer greater than or equal to 1. Based on the current discharge current of the battery, the voltage of the battery and the second equivalent resistance, the power on the switch branch is determined. If the power is less than or equal to the rated power of the switch branch, then the second equivalent resistance is used as the first preset resistance.

[0166] In this embodiment, there are J resistances in the first resistance set, and the resistance values of these J resistances are all less than the resistance value of the target resistance. The resistance with the largest resistance value among the J resistances is used as the second equivalent resistance, and the second equivalent resistance is substituted into the following formula to calculate the power on the switch branch:

[0167] P(v,i0)=vi0-i0 2 R2(5)

[0168] wherein P(v,i0) is the power on the switch branch, v is the voltage of the battery, i0 is the current discharge current of the battery, and R2 is the resistance value of the second equivalent resistance. If the power calculated according to formula (5) is less than or equal to the rated power of the switch branch, then the second equivalent resistance is used as the first preset resistance.

[0169] For example, in an embodiment, the first preset difference is set as 0.1 ohm. The first resistance set includes three equivalent resistors with resistance values of 5 ohm, 10 ohm and 20 ohm respectively, and the target resistance is 15 ohm. The absolute values of the differences between the resistance values of the equivalent resistors in the first resistance set and the resistance value of the target resistance are 10, 5 and 5 respectively, all of which are greater than 0.1. At this time, it is further needed to determine whether there are J resistors in the first resistance set with resistance values less than the resistance value of the target resistance. Since the resistance values of the two equivalent resistors with resistance values of 5 ohm and 10 ohm are both less than the resistance value of the target resistance, there are J resistors in the first resistance set with resistance values less than the resistance value of the target resistance, and J = 2. Meanwhile, the equivalent resistor with a resistance value of 10 ohm is the resistor with the largest resistance value among the J resistors (including the two equivalent resistors with resistance values of 5 ohm and 10 ohm), so the equivalent resistor with a resistance value of 10 ohm is the second equivalent resistor.

[0170] Then, when the second equivalent resistor exists, the current discharge current of the battery is determined based on the ratio of the voltage of the battery to the resistance value of the second equivalent resistor, and the power on the switch branch can be calculated by substituting the current discharge current of the battery and the resistance value of the second equivalent resistor into formula (5). If the power on the switch branch is not greater than (less than or equal to) the rated power of the switch branch, it can be determined that the switch branch can work safely and will not be damaged due to excessive power. Thus, it can be determined that the resistance value of the second equivalent resistor selected at this time is suitable for the current application scenario, and the second equivalent resistor can be used as the first preset resistance. In this embodiment, the resistor with a resistance value less than the resistance value of the target resistance is preferentially selected, so that sufficient discharge current can be obtained to meet the requirement that the discharge current of the battery is close to or equal to the target discharge current required.

[0171] In another embodiment, the circuit control method further includes the following steps: if there are no first equivalent resistor and second equivalent resistor in the first resistance set, and there are L resistors with resistance values greater than the resistance value of the target resistance in the first resistance set, a third equivalent resistor is obtained, and the third equivalent resistor is used as the first preset resistance. The third equivalent resistor is the resistor with the smallest resistance value among the L resistors, and L is an integer greater than or equal to 1.

[0172] Specifically, if there are no first equivalent resistor and second equivalent resistor in the first resistance set, there are no resistors with resistance values less than the resistance value of the target resistance in the first resistance set, so there are L resistors with resistance values greater than the resistance value of the target resistance in the first resistance set. The resistor with the smallest resistance value among the L resistors is used as the third equivalent resistor. The third equivalent resistor not only has a resistance value greater than the resistance value of the target resistance, but also has a resistance value closest to the resistance value of the target resistance.

[0173] For example, in an embodiment, the first preset difference is set as 0.1 ohm. The first resistance set includes three equivalent resistances with resistance values of 8 ohm, 10 ohm and 20 ohm respectively, and the target resistance is 6 ohm. The absolute values of the differences between the resistance values of the equivalent resistances in the first resistance set and the resistance value of the target resistance are 2, 4 and 14 respectively, all of which are greater than 0.1, and there is no first equivalent resistance in the first resistance set. And at this time, there is no resistance smaller than 6 ohm in the first resistance set, i.e. there is no second equivalent resistance in the first resistance set. Since the resistance values of the three equivalent resistances with resistance values of 8 ohm, 10 ohm and 20 ohm respectively are all greater than the resistance value of the target resistance, there are L resistances with resistance values greater than the resistance value of the target resistance in the first resistance set, and L=3. Meanwhile, the equivalent resistance with a resistance value of 8 ohm is the resistance with the smallest resistance value among the L resistances (including the three equivalent resistances with resistance values of 8 ohm, 10 ohm and 20 ohm respectively), so the equivalent resistance with a resistance value of 8 ohm is the third equivalent resistance.

[0174] In an embodiment, after step 804 is performed, the circuit control method further includes the following steps: Figure 11

[0175] Step 1101: determining a first difference based on the voltage of the battery, the first preset resistance and the rated power of the switching branch.

[0176] In some embodiments, the first difference can be calculated by the following formula:

[0177] Δ=v 2 -4R0P max (6)

[0178] wherein Δ is the first difference, v is the voltage of the battery, R0 is the resistance value of the first preset resistance, P max is the rated power of the switching branch.

[0179] Step 1102: if the first difference is less than or equal to a preset threshold, determining a maximum discharge current based on the ratio of the voltage of the battery to the resistance value of the first preset resistance.

[0180] Step 1103: if the target discharge current is less than the maximum discharge current, controlling the actual discharge current of the battery to be the target discharge current.

[0181] The preset threshold can be set according to actual application, which is not specifically limited in the embodiments of the present application. In some embodiments, the preset threshold can be set as 0.

[0182] Taking the preset threshold as 0 as an example. Please refer to Figure 11 and Figure 12 together. As shown in Figure 12 ​As shown, the horizontal axis represents current, and the vertical axis represents power. When the first difference Δ is not greater than 0, the curve for the first difference Δ is curve L1. At this time, the first difference Δ is generally less than the rated power P of the switch branch. max This ensures that the actual power of the switch branch is always less than the rated power under such circumstances. In other words, the discharge power of the switch branch can be ensured to be within the safe operating range, which can prevent the switch branch from being broken down, thereby extending the service life of the switch branch and improving the stability of the battery discharge circuit.

[0183] In another embodiment, the circuit control method further includes the following steps: if the first difference is greater than a preset threshold, then based on the current discharge current of the battery, the battery voltage, the resistance value of the first preset resistor, and the rated power of the switch branch, determine two discharge currents of the battery; if the target discharge current is less than or equal to the first discharge current of the two discharge currents, or the target discharge current is not less than the second discharge current of the two discharge currents, then control the actual discharge current of the battery to be the target discharge current; if the target discharge current is greater than the first discharge current and less than the second discharge current, then control the actual discharge current of the battery to be the first discharge current. Wherein, the first discharge current is less than the second discharge current.

[0184] In some implementations, the two discharge currents can be determined using the following formula:

[0185] -R0*i1 2 +v*i1-P max =0(7)

[0186] Where i1 is the current discharge current of the battery, R0 is the resistance value of the first preset resistor, v is the voltage of the battery, and P max This is the rated power of the switch branch.

[0187] Please refer to this again. Figure 12 When the first difference Δ is greater than 0, the curve for the first difference Δ is curve L2. Curve L2 is related to the rated power P. max The two axes intersect at two points, X1 and X2, respectively. X1 and X2 are both -R0*i1. 2 +v*i1-P max =0, and X1 and X2 are also the two discharge currents determined by formula (7). That is, based on the current discharge current of the battery, the battery voltage, the resistance value of the first preset resistor, and the rated power of the switch branch, the two discharge currents of the battery are determined to be the first discharge current X1 and the second discharge current X2. When the target discharge current is less than or equal to the first discharge current X1, or the target discharge current is greater than or equal to the second discharge current X2, by Figure 12 It can be seen that curve L2 always remains less than the rated power P.max , that is, the actual power of the switch branch can also continue to be kept from exceeding the rated power, at this time the actual discharge current of the battery can be set as the target discharge current. When the target discharge current is greater than the first discharge current X1 and the target discharge current is less than the second discharge current X2, the actual discharge current of the battery needs to be set as the first discharge current X1, so as to ensure that the actual power of the switch branch is always less than the rated power. Through the above process, the discharge power of the switch branch can also be controlled to be always within the safe working range, which can prevent the switch branch from being broken down, so as to prolong the service life of the switch branch and improve the stability of the battery discharge circuit.

[0188] Please refer to Figure 13 , Figure 13 A structure of a controller provided by another embodiment of the present application. The controller 1300 can be a microcontroller unit (MCU) or a digital signal processing (DSP) controller, etc.

[0189] As shown in Figure 13 , the controller 1300 includes at least one processor 1301 and a memory 1302. The memory 1302 can be built-in in the controller 1300 or externally disposed outside the controller 1300. The memory 1302 can also be a remotely disposed memory connected to the controller 1300 through a network.

[0190] The memory 1302 is a non-volatile computer readable storage medium, which can be used to store non-volatile software programs, non-volatile computer executable programs and modules. The memory 1302 can include a program storage area and a data storage area. The program storage area can store an operating system and application programs required by at least one function; the data storage area can store data created according to the use of the terminal, etc. In addition, the memory 1302 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 1302 can optionally include a memory remotely disposed relative to the processor 1301, which can be connected to the terminal through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0191] The processor 1301 executes various functions of the terminal and processes data by running or executing software programs and / or modules stored in the memory 1302 and calling data stored in the memory 1302, so as to monitor the terminal as a whole, for example, to implement the circuit control method in any embodiment of the present application.

[0192] The processor 1301 can be one or more, Figure 13 The processor 1301 and the memory 1302 can be connected by a bus or other means. The processor 1301 can include a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, or the like. The processor 1301 can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0193] In some embodiments, Figures 1-7 The controller 50 shown can be implemented as Figure 13 The controller 1300 shown.

[0194] The embodiments of the present application also provide a battery discharge device. The battery discharge device includes the battery discharge circuit 100 in any of the embodiments of the present application, and / or the controller 1300 in any of the embodiments of the present application.

[0195] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; under the idea of the present application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be simple, they are not provided in details; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery discharge circuit, characterized by comprising: The application relates to a battery discharge control circuit. The battery discharge control circuit comprises a resistance configuration branch, a current sampling branch, a switch branch, a signal amplification branch and a controller. The first end of the resistance configuration branch is connected with the first end of the battery, the second end of the resistance configuration branch is connected with the first end of the switch branch, the first end of the current sampling branch is connected with the second end of the battery, the second end of the current sampling branch is connected with the second end of the switch branch and the second end of the signal amplification branch respectively, the first end of the signal amplification branch and the third end of the resistance configuration branch are connected with the controller, and the third end of the signal amplification branch is connected with the third end of the switch branch. The resistance configuration branch is controlled by the controller and is configured as a first preset resistance. The current sampling branch is used for sampling the discharge current of the battery and outputting a sampling signal. The controller is used for outputting a voltage signal corresponding to the target discharge current of the battery. The signal amplification branch is used for receiving the sampling signal and the voltage signal and outputting an adjusting signal. The switch branch is used for receiving the adjusting signal and adjusting the conduction degree of the switch branch based on the adjusting signal. The battery is discharged through the first preset resistance and the switch branch, and the discharge current of the battery and the conduction degree of the switch branch present a positive correlation.

2. The battery discharge circuit of claim 1, wherein, The resistance configuration branch comprises N resistance units and a line connection switching branch. The line connection switching branch is connected with the N resistance units, the controller, the first end of the battery and the first end of the switch branch respectively. The line connection switching branch is controlled by the controller and is used for switching the connection relationship between different resistance units in the N resistance units and generating the first preset resistance.

3. The battery discharge circuit of claim 2, wherein, The N resistance units comprise a first resistance unit and a second resistance unit, and the line connection switching branch comprises a first switch, a second switch and a third switch. The first end of the first resistance unit is connected with the first end of the first switch and the first end of the battery respectively, the second end of the first switch is connected with the first end of the second resistance unit and the first end of the second switch respectively, the second end of the second switch is connected with the second end of the first resistance unit and the first end of the third switch respectively, the second end of the third switch is connected with the second end of the second resistance unit and the first end of the switch branch respectively, and the first switch, the second switch and the third switch are also connected with the controller. The controller switches the connection relationship between the first resistance unit and the second resistance unit by controlling the conduction and shutdown of the first switch, the second switch and the third switch.

4. The battery discharge circuit of claim 3, wherein, The first resistance unit comprises a first resistance, a second resistance and a fourth switch, and the second resistance unit comprises a third resistance, a fourth resistance and a fifth switch. The first resistor and the second resistor are connected in series, the second resistor and the fourth switch are connected in parallel, a non-series connection end of the first resistor is a first end of the first resistor unit, a non-series connection end of the second resistor is a second end of the first resistor unit, the third resistor and the fourth resistor are connected in series, the fourth resistor and the fifth switch are connected in parallel, a non-series connection end of the third resistor is a first end of the second resistor unit, a non-series connection end of the fourth resistor is a second end of the second resistor unit.

5. The battery discharge circuit of claim 1, wherein, The current sampling branch comprises a first sampling resistor; A first end of the first sampling resistor is connected with the second end of the battery, and a second end of the first sampling resistor is connected with the second end of the switch branch.

6. The battery discharge circuit of claim 1, wherein, The switch branch comprises a first switch tube; A first end of the first switch tube is connected with a third end of the signal amplification branch, a second end of the first switch tube is connected with a second end of the current sampling branch, and a third end of the first switch tube is connected with a second end of the resistor configuration branch.

7. The battery discharge circuit of claim 1, wherein, The signal amplification branch comprises a first amplification unit and a second amplification unit; A first end of the first amplification unit is connected with the second end of the switch branch, a second end of the first amplification unit is connected with a first end of the second amplification unit, a second end of the second amplification unit is connected with the controller, and a third end of the second amplification unit is connected with a third end of the switch branch; The first amplification unit is configured to receive the sampling signal and amplify the sampling signal; The second amplification unit is configured to receive the voltage signal and the amplified sampling signal and output the adjusted signal.

8. The battery discharge circuit of claim 7, wherein, The first amplification unit comprises a first operational amplifier, a fifth resistor and a sixth resistor; A first input end of the first operational amplifier is connected with the second end of the switch branch, second input ends of the first operational amplifier are connected with a first end of the fifth resistor and a first end of the sixth resistor, an output end of the first operational amplifier is connected with a second end of the fifth resistor and a first end of the second amplification unit, and a second end of the sixth resistor is grounded.

9. The battery discharge circuit of claim 7, wherein, The second amplification unit comprises a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a second capacitor, a third capacitor and a second operational amplifier; A first end of the seventh resistor is connected with a second end of the first amplification unit, second ends of the seventh resistor are respectively connected with a first end of the eighth resistor, a first end of the first capacitor, a first end of the second capacitor and a second input end of the second operational amplifier, a second end of the eighth resistor is respectively connected with a first end of the ninth resistor and the controller, second ends of the ninth resistor are respectively connected with a second end of the first capacitor, a first end of the third capacitor and a first input end of the second operational amplifier, an output end of the second operational amplifier is respectively connected with a second end of the second capacitor and a third end of the switch branch, and a second end of the third capacitor is grounded.

10. A circuit control method characterized by, The method for controlling the battery discharge circuit as claimed in any one of claims 1-9, the method comprising: Switching connection relationships between different resistance units in the N resistance units of the resistance configuration branch, to obtain M connection states of the N resistance units, where M and N are integers greater than or equal to 1; For each of the M connection states, changing the number of effective resistances in the N resistance units, determining a resistance set in each connection state, and obtaining M resistance sets in the M connection states; Based on a preset target set, determining a first resistance set in the M resistance sets that matches the target set; In the first resistance set, a first preset resistance is obtained, and the battery is discharged through the first preset resistance.

11. The circuit control method according to claim 10, wherein The method further comprises: Obtaining the intersection of the target set and each of the M resistance sets; According to the intersection and the target set, determining a resistance coverage rate; For each of the M resistance sets, obtaining a maximum discharge current of the battery, and obtaining a target discharge current of the battery, and determining a current coverage rate based on the ratio of the maximum discharge current to the target discharge current; According to the resistance coverage rate and the current coverage rate of each of the M resistance sets, determining a matching rate of each of the M resistance sets, and obtaining M matching rates in the M resistance sets; Determining the maximum value in the M matching rates, and determining the resistance set corresponding to the maximum value as the first resistance set.

12. The circuit control method according to claim 10, wherein The method further comprises: Based on the ratio of the voltage of the battery to the target discharge current of the battery, determining a target resistance; If the absolute value of the difference between the resistance value of the first equivalent resistance in the first resistance set and the resistance value of the target resistance is less than a first preset difference, the first equivalent resistance is taken as the first preset resistance.

13. The circuit control method according to claim 12, wherein The method further comprises: If the first equivalent resistance does not exist in the first resistance set, and there are J resistances in the first resistance set whose resistance values are less than the resistance value of the target resistance, a second equivalent resistance is obtained, where the second equivalent resistance is the resistance with the largest resistance value in the J resistances, and J is an integer greater than or equal to 1; Based on the current discharge current of the battery, the voltage of the battery, and the second equivalent resistance, determining the power on the switch branch; If the power is less than or equal to the rated power of the switch branch, the second equivalent resistance is taken as the first preset resistance.

14. The circuit control method according to claim 13, wherein The method further comprises: If the first equivalent resistance and the second equivalent resistance do not exist in the first resistance set, and there are L resistances in the first resistance set whose resistance values are greater than the resistance value of the target resistance, a third equivalent resistance is obtained and taken as the first preset resistance, where the third equivalent resistance is the resistance with the smallest resistance value in the L resistances, and L is an integer greater than or equal to 1.

15. The circuit control method according to claim 10, wherein After obtaining the first preset resistance in the first resistance set, the method further comprises: determining a first difference value based on the voltage of the battery, the first preset resistance, and a rated power of the switch branch; if the first difference value is less than or equal to a preset threshold, determining a maximum discharge current based on a ratio of the voltage of the battery to a resistance value of the first preset resistance; if the target discharge current of the battery is less than the maximum discharge current, controlling an actual discharge current of the battery to be the target discharge current; if the target discharge current of the battery is greater than or equal to the maximum discharge current, controlling the actual discharge current of the battery to be the maximum discharge current.

16. The circuit control method according to claim 15, wherein The method further comprises: if the first difference value is greater than the preset threshold, determining two discharge currents of the battery based on the current discharge current of the battery, the voltage of the battery, the resistance value of the first preset resistance, and the rated power of the switch branch; if the target discharge current is less than or equal to a first discharge current of the two discharge currents, or the target discharge current is greater than or equal to a second discharge current of the two discharge currents, controlling the actual discharge current of the battery to be the target discharge current, wherein the first discharge current is less than the second discharge current; if the target discharge current is greater than the first discharge current and less than the second discharge current, controlling the actual discharge current of the battery to be the first discharge current.

17. A controller characterized by comprising: comprise: at least one processor and a memory connected with the at least one processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 10-16.

18. A battery discharge device, comprising: comprise the battery discharge circuit of any one of claims 1-9, and / or the controller of claim 17.

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