Battery test circuit, test equipment and test system

Abstract

The embodiment of the invention discloses a battery test circuit, a test device and a test system, an energy storage battery and a to-be-tested battery are respectively connected through a first connection module and a second connection module, for example, a control module controls a bidirectional DCDC module to be switched to a charging state in a battery charging stage of performing a charging test on the to-be-tested battery; in the battery charging stage, the bidirectional DCDC module is controlled to be switched to the charging state to enable the energy storage battery to charge the to-be-tested battery, and in the battery discharging stage in which a discharging test is performed on the to-be-tested battery, the bidirectional DCDC module is controlled to be switched to the discharging state to enable the to-be-tested battery to charge the energy storage battery, and in the battery charging stage, the energy storage battery charges the to-be-tested battery to perform a charging test on the to-be-tested battery. And the to-be-tested battery charges the energy storage battery in the battery discharging stage so as to carry out a discharging test, and the electric energy output by the to-be-tested battery can be recycled, so that the electric energy utilization rate in the battery testing process can be effectively improved, and the battery testing cost is reduced.

Description

Technical Field

[0001] This application relates to battery testing technology, and more particularly to a battery testing circuit, testing equipment, and testing system. Background Technology

[0002] With the rapid development of battery technology (such as lithium batteries), batteries are widely used in various industries. As market demand grows, more and more batteries are being produced. In order to ensure the quality and safety of batteries, more testing equipment and requirements are needed for testing battery functions such as capacity.

[0003] Currently, battery testing is generally conducted using charging instruments or electronic load instruments. For example, charging instruments are used to convert AC voltage into DC voltage to charge the battery, or electronic load instruments are used to discharge the battery for discharge testing. However, this battery testing method wastes a lot of electrical energy, resulting in excessively high battery testing costs. Summary of the Invention

[0004] This application provides a battery testing circuit, testing equipment, and testing system to solve the technical problem that battery testing methods in related technologies waste a lot of electrical energy, resulting in excessively high battery testing costs. It can effectively improve the energy utilization rate of the battery testing process and reduce battery testing costs.

[0005] In a first aspect, embodiments of this application provide a battery testing circuit, including a control module, a bidirectional DC-DC module, a first connection module, and a second connection module. The first connection module is used to connect to an energy storage battery, and the second connection module is used to connect to the battery under test, wherein: The control terminal of the bidirectional DC-DC module is connected to the control module, the first connection terminal of the bidirectional DC-DC module is connected to the first connection module, and the second connection terminal of the bidirectional DC-DC module is connected to the second connection module. The control module is used to control the bidirectional DC-DC module to switch to a charging state during the battery charging phase of the battery under test, so that the energy storage battery charges the battery under test. The control module is also used to control the bidirectional DC-DC module to switch to a discharging state during the battery discharging phase of the battery under test, so that the battery under test charges the energy storage battery.

[0006] Furthermore, controlling the bidirectional DC-DC module to switch to a charging state so that the energy storage battery charges the battery under test includes: Control the bidirectional DC-DC module to switch to boost charging mode, so as to charge the battery under test after performing energy storage and boosting processing on the electrical energy provided by the energy storage battery; and / or The bidirectional DC-DC module is controlled to switch to buck charging mode so that the power supplied by the energy storage battery is stepped down before being used to charge the battery under test.

[0007] Furthermore, controlling the bidirectional DC-DC module to switch to a discharge state so that the battery under test charges the energy storage battery includes: Control the bidirectional DC-DC module to switch to boost discharge mode, so as to charge the energy storage battery after performing energy storage boost processing on the electrical energy provided by the battery under test; and / or The bidirectional DC-DC module is controlled to switch to a step-down discharge state to step down the electrical energy provided by the battery under test before charging the energy storage battery.

[0008] Furthermore, the bidirectional DC-DC module includes a DC-DC controller, an H-bridge circuit, and an energy storage circuit, wherein: The control input terminal of the DC-DC controller is connected to the control module, the control output terminal of the DC-DC controller is connected to the control terminal of the H-bridge circuit, and the energy storage circuit is connected in series between the midpoint of the first arm and the midpoint of the second arm of the H-bridge circuit. The first connection module is connected to the first arm of the H-bridge circuit, and the second connection module is connected to the second arm of the H-bridge circuit.

[0009] Furthermore, in the boost charging state, the DC-DC controller controls the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can store the electrical energy provided by the energy storage battery, and controls the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can charge the battery under test. In buck charging mode, the DC-DC controller controls the upper transistors of the first and second bridge arms of the H-bridge circuit to conduct, so that the energy storage battery charges the battery under test through the energy storage circuit.

[0010] Furthermore, in the boost discharge state, the DCDC controller controls the lower transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can store the electrical energy provided by the battery under test, and controls the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can charge the energy storage battery. In the step-down discharge state, the DC-DC controller controls the upper transistors of the first and second bridge arms of the H-bridge circuit to conduct, so that the battery under test charges the energy storage battery through the energy storage circuit.

[0011] Furthermore, the H-bridge circuit includes a first switch, a second switch, a third switch, and a fourth switch. The control terminals of the first switch, the second switch, the third switch, and the fourth switch are all connected to the control output terminal of the DC-DC controller, wherein: The first connection terminal of the first switching transistor is connected to the positive terminal of the second connection module, the second connection terminal of the first switching transistor is connected to the first connection terminal of the third switching transistor and the second connection terminal of the energy storage circuit, and the second connection terminal of the third switching transistor is connected to the negative terminal of the second connection module and the second connection terminal of the fourth switching transistor. The first connection terminal of the second switching transistor is connected to the positive terminal of the first connection module, the second connection terminal of the second switching transistor is connected to the first connection terminal of the fourth switching transistor and the first connection terminal of the energy storage circuit, and the second connection terminal of the fourth switching transistor is connected to the negative terminal of the first connection module.

[0012] Furthermore, it also includes a current acquisition module, which is connected to the second connection module, wherein: The current acquisition module is used to acquire the current of the battery under test connected in the second connection module.

[0013] In a second aspect, embodiments of this application provide a testing device including a battery testing circuit as described in any of the first aspects.

[0014] In a third aspect, embodiments of this application provide a testing system, including the testing equipment as described in the second aspect and a host computer, wherein the host computer is connected to the control module in the testing equipment.

[0015] In this embodiment, the energy storage battery and the battery under test are connected via a first connection module and a second connection module, respectively. For example, during the battery charging phase of the battery under test, the control module controls the bidirectional DC-DC module to switch to the charging state so that the energy storage battery charges the battery under test. During the battery discharging phase of the battery under test, the control module controls the bidirectional DC-DC module to switch to the discharging state so that the battery under test charges the energy storage battery. During the battery charging phase, the energy storage battery charges the battery under test for charging testing. During the battery discharging phase, the battery under test charges the energy storage battery for discharging testing. The electrical energy output by the battery under test can be recovered and reused, which can effectively improve the energy utilization rate of the battery testing process and reduce the battery testing cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a battery testing circuit provided in an embodiment of this application; Figure 2This is a circuit diagram of a battery testing circuit provided in an embodiment of this application; Figure 3 This is a schematic diagram of another battery testing circuit provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a testing device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a testing system provided in an embodiment of this application.

[0017] Reference numerals: 1. Control module; 2. Bidirectional DC-DC module; 21. DC-DC controller; 22. H-bridge circuit; 221. First switching transistor; 222. Second switching transistor; 223. Third switching transistor; 224. Fourth switching transistor; 23. Energy storage circuit; 3. First connection module; 4. Second connection module; 5. Energy storage battery; 6. Battery under test; 71. Current acquisition chip; 72. Sampling resistor; 8. Communication module; 9. Display module. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not all of them. In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The above process can be terminated when its operation is complete, but additional steps not included in the figures may also be possible. The above process may correspond to a method, function, procedure, subroutine, subroutine, etc.

[0019] Figure 1 A schematic diagram of a battery testing circuit according to an embodiment of this application is provided. (Reference) Figure 1The battery testing circuit includes a control module 1 (e.g., an MCU), a bidirectional DC-DC module 2, a first connection module 3, and a second connection module 4. The first connection module 3 is used to connect to an energy storage battery 5, and the second connection module 4 is used to connect to a battery under test 6 (e.g., various types of batteries that a PACK factory needs to test). Both the energy storage battery 5 and the battery under test 6 are rechargeable batteries (e.g., lithium batteries). Optionally, the first connection module 3 and the second connection module 4 can be interfaces for connecting the corresponding batteries. Optionally, a power management chip can be configured in the battery under test 6 or the second connection module 4 to manage the charging and discharging of the battery under test 6. In one embodiment, a charging module for charging the energy storage battery 5 can be connected to the first connection module 3 to replenish the energy storage battery 5 and ensure sufficient power for battery testing.

[0020] The bidirectional DC-DC module 2 provided in this application can be used to control the bidirectional transmission of electrical energy by controlling the direction of current. The bidirectional DC-DC module 2 is configured with a control terminal, a first connection terminal and a second connection terminal. Both the first connection terminal and the second connection terminal are configured with a first interface and a second interface. The control terminal can control the conduction and cutoff between the first interface and the second interface of the first connection terminal and the first interface and the second interface of the second connection terminal, thereby controlling the direction of current between the first connection terminal and the second connection terminal.

[0021] The control terminal of the bidirectional DC-DC module 2 is connected to the control module 1, the first connection terminal of the bidirectional DC-DC module 2 is connected to the first connection module 3, and the second connection terminal of the bidirectional DC-DC module 2 is connected to the second connection module 4. Thus, the current can be controlled to flow from the first connection module 3 to the second connection module 4, or from the second connection module 4 to the first connection module 3.

[0022] The testing phase of the battery under test 6 includes a battery charging phase for charging the battery under test 6 and a battery discharging phase for discharging the battery under test 6. In the battery charging phase, this application provides charging power to the battery under test 6 through the energy storage battery 5, and in the battery discharging phase, it utilizes the energy storage battery 5 to recover the electrical energy released by the battery under test 6. Optionally, the battery testing of a battery under test 6 can only perform charging tests, only discharging tests, or both charging and discharging tests; the order of the charging and discharging tests is not required. Correspondingly, this application can send a control signal to the control terminal of the bidirectional DC-DC module 2 through the control module 1, causing the bidirectional DC-DC module 2 to switch between charging and discharging states. In the charging state, the current flows from the first connection terminal to the second connection terminal; in the discharging state, the current flows from the second connection terminal to the first connection terminal. The charging and discharging states can be understood as the charging and discharging states of the battery under test 6. Optionally, aging tests can also be performed on the battery under test 6 by controlling its charging and discharging.

[0023] The control module 1 provided in this application can be used to control the bidirectional DC-DC module 2 to switch to charging mode during the battery charging phase of the battery under test 6, so that the energy storage battery 5 charges the battery under test 6. At this time, relevant parameters of the battery under test 6 (such as voltage, current, temperature, etc.) can be collected for charging testing (for example, by installing a corresponding acquisition module at the second connection module 4 or the battery under test 6). The control module 1 is also used to control the bidirectional DC-DC module 2 to switch to discharging mode during the battery discharging phase of the battery under test 6, so that the battery under test 6 charges the energy storage battery 5 while discharging. At this time, relevant parameters of the battery under test 6 (such as voltage, current, temperature, etc.) can be collected for discharging testing.

[0024] In one possible embodiment, the charging states provided in this application may include boost charging states and / or buck charging states, and the discharging states may include boost discharging states and / or buck discharging states. Boost charging states can be understood as follows: when the voltage provided by the energy storage battery 5 is lower than the voltage of the battery under test 6, the voltage provided by the energy storage battery 5 needs to be boosted to ensure that the energy provided by the energy storage battery 5 can be effectively injected into the battery under test 6. Buck charging states can be understood as follows: when the voltage provided by the energy storage battery 5 is higher than the voltage of the battery under test 6, the voltage provided by the energy storage battery 5 needs to be bucked to ensure that the energy provided by the energy storage battery 5 can be effectively injected into the battery under test 6, preventing the high voltage of the energy storage battery 5 from damaging the battery under test 6. Boost discharging states can be understood as follows: when the voltage provided by the battery under test 6 is lower than the voltage of the energy storage battery 5, the voltage provided by the battery under test 6 needs to be boosted to ensure that the energy provided by the battery under test 6 can be effectively injected into the energy storage battery 5. The voltage reduction discharge state can be understood as follows: when the voltage provided by the battery under test 6 is higher than the voltage of the energy storage battery 5, the voltage provided by the battery under test 6 needs to be reduced so that the energy provided by the battery under test 6 can be effectively injected into the energy storage battery 5, and the high voltage of the battery under test 6 can be used to prevent the energy storage battery 5 from being damaged by the high voltage of the battery under test 6.

[0025] In one possible embodiment, the present application controls the bidirectional DC-DC module 2 to switch to a charging state so that the energy storage battery 5 charges the battery under test 6. This can be achieved by: controlling the bidirectional DC-DC module 2 to switch to a boost charging state to charge the battery under test 6 after energy storage boosting of the electrical energy provided by the energy storage battery 5; and / or, controlling the bidirectional DC-DC module 2 to switch to a buck charging state to charge the battery under test 6 after bucking of the electrical energy provided by the energy storage battery 5.

[0026] The charging test of a battery under test 6 can be performed by only performing a boost charging test, only performing a buck charging test, or performing both boost charging and buck charging tests. The order of the boost charging and buck charging tests is not required. This application sends corresponding control signals to the bidirectional DC-DC module 2 through the control module 1, controlling the bidirectional DC-DC module 2 to switch between boost charging and buck charging states, so as to perform energy storage and boosting processing on the electrical energy provided by the energy storage battery 5 before charging the battery under test 6, or perform buck processing on the electrical energy provided by the energy storage battery 5 before charging the battery under test 6, thereby achieving flexible control of battery charging test.

[0027] In one possible embodiment, the present application controls the bidirectional DC-DC module 2 to switch to a discharge state so that the battery under test 6 charges the energy storage battery 5. This can be achieved by: controlling the bidirectional DC-DC module 2 to switch to a boost discharge state so that the electrical energy provided by the battery under test 6 is processed for energy storage and boosted before being used to charge the energy storage battery 5; and / or controlling the bidirectional DC-DC module 2 to switch to a buck discharge state so that the electrical energy provided by the battery under test 6 is processed for bucked before being used to charge the energy storage battery 5.

[0028] The discharge test of a battery under test 6 can be performed by only performing a boost discharge test, only performing a buck discharge test, or performing both boost and buck discharge tests. The order of the boost and buck discharge tests is not required. This application sends corresponding control signals to the bidirectional DC-DC module 2 through the control module 1, controlling the bidirectional DC-DC module 2 to switch between boost and buck discharge states, so as to perform energy storage boost processing on the electrical energy provided by the battery under test 6 and then charge the energy storage battery 5, or control the bidirectional DC-DC module 2 to switch to buck discharge state, so as to perform buck processing on the electrical energy provided by the battery under test 6 and then charge the energy storage battery 5, thereby realizing flexible control of battery discharge testing.

[0029] In one embodiment, such as Figure 2 A circuit diagram of a battery testing circuit is provided. The bidirectional DC-DC module 2 provided in this application includes a DC-DC controller 21 (e.g., a DC-DC control chip), an H-bridge circuit 22, and an energy storage circuit 23. The control input terminal of the DC-DC controller 21 is connected to the control module 1, and the control output terminal of the DC-DC controller 21 is connected to the control terminal of the H-bridge circuit 22. The energy storage circuit 23 is connected in series between the midpoints of the first and second arms of the H-bridge circuit 22. A first connection module 3 is connected to the first arm of the H-bridge circuit 22, and a second connection module 4 is connected to the second arm of the H-bridge circuit 22. The first and second arms of the H-bridge circuit 22 can be a left arm (connected to the first connection module 3) and a right arm (connected to the second connection module 4). The midpoint of the first arm is the connection point between the upper and lower tubes in the first arm, and the midpoint of the second arm is the connection point between the upper and lower tubes in the second arm. The lower end of the first bridge arm and the lower end of the second bridge arm of the H-bridge circuit 22 are connected, while the upper end of the first bridge arm and the upper end of the second bridge arm are not connected. Optionally, the energy storage circuit 23 may include an inductor, with the two ends of the inductor corresponding to the first connection terminal and the second connection terminal of the energy storage circuit 23, respectively.

[0030] The energy storage circuit 23 provided in this application can be used to store the electrical energy provided by the energy storage battery 5 or the battery under test 6, and to discharge the battery under test 6 or the energy storage battery 5. It can also be used to limit the current and reduce the voltage of the electrical energy flowing to the energy storage battery 5 or the battery under test 6. The control module 1 can send corresponding control signals to the control input terminal of the DCDC controller 21, so that the DCDC controller 21 controls the on and off of each switch in the H-bridge circuit 22 through the control output terminal, so that the bidirectional DCDC module 2 can switch between boost charging state, buck charging state, boost discharging state and buck discharging state, so as to realize flexible control of battery testing.

[0031] In one embodiment, the DC-DC controller 21 can control the first upper arm transistor and the second lower arm transistor of the H-bridge circuit 22 to conduct (and the first lower arm transistor and the second upper arm transistor to turn off) during boost charging, so that the energy storage circuit 23 can store the electrical energy provided by the energy storage battery 5, and control the first upper arm transistor and the second upper arm transistor of the H-bridge circuit 22 to conduct (and the first lower arm transistor and the second lower arm transistor to turn off) so that the energy storage circuit 23 can charge the battery under test 6. Specifically, by alternately controlling the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22, and controlling the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22, the energy storage battery 5 charges the energy storage circuit 23 when the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22 are conducting. When the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22 are conducting, the energy storage battery 5 and the energy storage circuit 23 charge the battery under test 6. At this time, the voltage charged to the battery under test 6 is higher than the voltage of the energy storage battery 5. By controlling the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm, and the duration and time ratio of the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm, the voltage charged to the battery under test 6 can be controlled.

[0032] In one embodiment, the DC-DC controller 21 can also be controlled to turn on the upper transistors of the first and second arms of the H-bridge circuit 22 (while turning off the lower transistors of the first and second arms) during the buck charging state. This allows the energy storage battery 5 to charge the battery under test 6 via the energy storage circuit 23, and achieves a buck effect on the energy supplied by the energy storage battery 5 under the current limiting characteristics of the energy storage circuit 23, thereby reducing the charging voltage of the battery under test 6. The charging voltage to the battery under test 6 can be controlled by alternately controlling the conduction duration and time ratio of the upper transistors of the first and second arms of the H-bridge circuit 22.

[0033] In one embodiment, the DC-DC controller 21 can control the first lower arm transistor and the second upper arm transistor of the H-bridge circuit 22 to conduct (and the first upper arm transistor and the second lower arm transistor to turn off) in a boost discharge state, so that the energy storage circuit 23 can perform energy storage processing on the electrical energy provided by the battery under test 6, and control the first upper arm transistor and the second upper arm transistor of the H-bridge circuit 22 to conduct (and the first lower arm transistor and the second lower arm transistor to turn off) so that the energy storage circuit 23 can charge the energy storage battery 5. Specifically, by alternately controlling the conduction of the lower transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit 22, and controlling the conduction of the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit 22, when the lower transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit 22 are conducting, the battery under test 6 charges the energy storage circuit 23, and when the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit 22 are conducting, the battery under test 6 and the energy storage circuit 23 charge the energy storage battery 5. At this time, the voltage charged to the energy storage battery 5 is higher than the voltage of the battery under test 6. By controlling the conduction of the lower transistor of the first bridge arm and the upper transistor of the second bridge arm, and the duration and time ratio of the upper transistor of the first bridge arm and the upper transistor of the second bridge arm, the voltage charged to the energy storage battery 5 can be controlled.

[0034] In one embodiment, the DC-DC controller 21 can also be controlled to turn on the upper transistors of the first and second arms of the H-bridge circuit 22 (while turning off the lower transistors of the first and second arms) during the step-down discharge state. This allows the battery under test 6 to charge the energy storage battery 5 via the energy storage circuit 23, and the current-limiting characteristics of the energy storage circuit 23 achieve a step-down effect on the electrical energy supplied to the battery under test 6, reducing the charging voltage to the energy storage battery 5. The charging voltage to the energy storage battery 5 can be controlled by alternately controlling the conduction duration and time ratio of the upper transistors of the first and second arms of the H-bridge circuit 22.

[0035] In one possible embodiment, the H-bridge circuit 22 provided in this application may include a first switch 221, a second switch 222, a third switch 223, and a fourth switch 224 (corresponding to the upper switch of the second bridge arm, the upper switch of the first bridge arm, the lower switch of the second bridge arm, and the lower switch of the first bridge arm, respectively). The control terminals of the first switch 221, the second switch 222, the third switch 223, and the fourth switch 224 are all connected to the control output terminal of the DC-DC controller 21. Optionally, the (first to fourth) switches provided in this application may be MOS transistors (e.g., NMOS transistors), with the control terminal of the switch being the gate, the first connection terminal being the drain, and the second connection terminal being the source.

[0036] Specifically, the first connection terminal of the first switching transistor 221 is connected to the positive terminal of the second connection module 4; the second connection terminal of the first switching transistor 221 is connected to the first connection terminal of the third switching transistor 223 and the second connection terminal of the energy storage circuit 23; the second connection terminal of the third switching transistor 223 is connected to the negative terminal of the second connection module 4 and the second connection terminal of the fourth switching transistor 224. The first connection terminal of the second switching transistor 222 is connected to the positive terminal of the first connection module 3; the second connection terminal of the second switching transistor 222 is connected to the first connection terminal of the fourth switching transistor 224 and the first connection terminal of the energy storage circuit 23; and the second connection terminal of the fourth switching transistor 224 is connected to the negative terminal of the first connection module 3.

[0037] In the boost charging state, the second switch 222 and the third switch 223 are turned on, while the fourth switch 224 and the first switch 221 are turned off, so that the energy storage circuit 23 can store the electrical energy provided by the energy storage battery 5. Additionally, the second switch 222 and the first switch 221 are turned on, while the fourth switch 224 and the third switch 223 are turned off, so that the energy storage circuit 23 can charge the battery under test 6. In the buck charging state, the first switch 221 and the second switch 222 are turned on, while the third switch 223 and the fourth switch 224 are turned off, so that the energy storage battery 5 can charge the battery under test 6 through the energy storage circuit 23, thus achieving buck charging of the battery under test 6.

[0038] In boost discharge mode, the fourth switch 224 and the first switch 221 are turned on, while the second switch 222 and the third switch 223 are turned off, so that the energy storage circuit 23 can store the electrical energy supplied by the battery under test 6. Simultaneously, the second switch 222 and the first switch 221 are turned on, while the fourth switch 224 and the third switch 223 are turned off, so that the energy storage circuit 23 can charge the energy storage battery 5. In buck discharge mode, the first switch 221 and the second switch 222 are turned on, while the third switch 223 and the fourth switch 224 are turned off, so that the battery under test 6 can charge the energy storage battery 5 through the energy storage circuit 23. While discharging the battery under test 6, the energy storage battery 5 is simultaneously charged at a lower voltage, achieving energy recovery.

[0039] In one embodiment, the control module 1 can be connected to the DC-DC controller 21 based on the I2C communication protocol (for example, the SCL2 and SDA2 pins of the control module 1 are connected to the SCL and SDA pins of the DC-DC controller 21), thereby realizing the communication connection between the control module 1 and the DC-DC controller 21. The control module 1 can set the control parameters of the DC-DC controller 21 through the I2C communication interface. The DC-DC controller 21 controls the switching of the four switching transistors according to the control parameters to control the output current and voltage. For example, the current can be set between 1A and 80A, and the voltage between 3 and 100V, which is suitable for testing 12V to 84V batteries. The DIR pin of control module 1 is also connected to the DIR pin (i.e., control input terminal) of DCDC controller 21. When the energy storage battery 5 needs to charge the battery under test 6, the DIR pin of control module 1 is set to low level (LOW) to control the DCDC controller 21 to control the switching of the four switching transistors to achieve the purpose of charging the battery under test 6. When the battery under test 6 needs to charge the energy storage battery 5, the DIR pin of control module 1 is set to high level (HIGH) to control the DCDC controller 21 to control the switching of the four switching transistors to achieve the purpose of discharging the battery under test 6.

[0040] For example, the DC-DC controller 21 can be controlled to turn on the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22 (and turn off the lower transistor of the first bridge arm and the upper transistor of the second bridge arm) when the DC-DC controller 21 is in boost charging mode, so that the energy storage circuit 23 can store the electrical energy provided by the energy storage battery 5, and control the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit 22 to turn on (and turn off the lower transistor of the first bridge arm and the lower transistor of the second bridge arm) so that the energy storage circuit 23 can charge the battery under test 6. Specifically, by alternately controlling the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22, and controlling the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22, the energy storage battery 5 charges the energy storage circuit 23 when the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22 are conducting. When the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit 22 are conducting, the energy storage battery 5 and the energy storage circuit 23 charge the battery under test 6. At this time, the voltage charged to the battery under test 6 is higher than the voltage of the energy storage battery 5. By controlling the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm, and the duration and time ratio of the conduction of the upper transistor of the first bridge arm and the lower transistor of the second bridge arm, the voltage charged to the battery under test 6 can be controlled.

[0041] In one embodiment, the battery testing circuit provided in this application further includes a current acquisition module, which is connected to the second connection module 4. For example, the current sampling module provided in this application may include a sampling resistor 72 and a current acquisition chip 71 (e.g., a CS1237 chip). The sampling resistor 72 is connected in series with the second connection module 4, and the positive sampling terminal (AINP pin) and negative sampling terminal (AINN pin) of the current acquisition chip 71 are respectively connected to the two ends of the sampling resistor 72. Specifically, the first connection terminal of the sampling resistor 72 is connected to the end of the lower transistor of the second bridge arm of the H-bridge circuit 22 and the positive sampling terminal of the current acquisition chip 71, and the second connection terminal of the sampling resistor 72 is connected to the negative terminal of the second connection module 4 and the negative sampling terminal of the current acquisition chip 71. The two ends of the sampling resistor 72 are also connected to the current feedback pins (IFB+ and IFB-) of the DCDC controller 21. The control module 1 can be connected to the current acquisition chip 71 based on the I2C communication protocol (e.g., the SCL1 and SDA1 pins of the control module 1 are connected to the SCLK and SCDA pins of the current acquisition chip 71). The current acquisition module is used to acquire the current of the battery under test 6 connected in the second connection module 4. It can use the acquired current to calculate the remaining capacity and SOC of the battery under test 6 based on the Coulomb calculation method. It can also detect whether the capacity of the battery under test 6 is sufficient based on the remaining capacity and SOC, and detect inferior batteries that are made with inferior materials or are of poor quality.

[0042] like Figure 3 As shown in the schematic diagram of another battery testing circuit provided in this application, the battery testing circuit also includes a communication module 8, which is connected to the control module 1. The communication module 8 is used to connect to external devices (such as mobile phones, tablets, computers, etc.). The communication module 8 can be a wired communication module and / or a wireless communication module, such as a Bluetooth communication module, a ZigBee communication module, a WiFi communication module, a 3G, 4G, or 5G communication module, a CAN communication module, an RS485 communication module, etc. External devices can connect to the control module 1 through the communication module 8, allowing users to observe the data collected by the control module 1 and control the control module 1, thereby performing battery testing and facilitating user operation.

[0043] The battery testing circuit provided in this application also includes a display module 9 (e.g., an LCD screen). The display module 9 is connected to the control module 1. The control module 1 is used to control the display module 9 to display battery test information. Users can intuitively understand the battery test information through the display module 9, thereby improving battery testing efficiency.

[0044] As described above, the energy storage battery 5 and the battery under test 6 are respectively connected through the first connection module 3 and the second connection module 4. For example, during the battery charging stage of the battery under test 6, the control module 1 controls the bidirectional DC-DC module 2 to switch to the charging state so that the energy storage battery 5 charges the battery under test 6. During the battery discharging stage of the battery under test 6, the control module 1 controls the bidirectional DC-DC module 2 to switch to the discharging state so that the battery under test 6 charges the energy storage battery 5. During the battery charging stage, the energy storage battery 5 charges the battery under test 6 to perform a charging test. During the battery discharging stage, the battery under test 6 charges the energy storage battery 5 to perform a charging test. The electrical energy output by the battery under test 6 can be recovered and reused, which can effectively improve the energy utilization rate of the battery testing process and reduce the battery testing cost.

[0045] Figure 4 A schematic diagram of a testing device provided in an embodiment of this application is given. (Reference) Figure 4 The testing equipment includes a battery testing circuit as provided in any of the above embodiments.

[0046] As described above, the energy storage battery and the battery under test are respectively connected through the first connection module and the second connection module. For example, during the battery charging phase of the battery under test, the control module controls the bidirectional DC-DC module to switch to the charging state so that the energy storage battery charges the battery under test. During the battery discharging phase of the battery under test, the control module controls the bidirectional DC-DC module to switch to the discharging state so that the battery under test charges the energy storage battery. During the battery charging phase, the energy storage battery charges the battery under test for charging test. During the battery discharging phase, the battery under test charges the energy storage battery for discharging test. The electrical energy output by the battery under test can be recovered and reused, which can effectively improve the energy utilization rate of the battery testing process and reduce the battery testing cost.

[0047] Figure 5 A schematic diagram of the structure of a testing system provided in an embodiment of this application is given. (Reference) Figure 5 The testing system includes the testing equipment and host computer as provided in the above embodiments. The host computer is connected to the control module in the testing equipment. The host computer can be used to observe the data collected by the control module and control the control module to perform battery testing, which is convenient for users.

[0048] As described above, the energy storage battery and the battery under test are respectively connected through the first connection module and the second connection module. For example, during the battery charging phase of the battery under test, the control module controls the bidirectional DC-DC module to switch to the charging state so that the energy storage battery charges the battery under test. During the battery discharging phase of the battery under test, the control module controls the bidirectional DC-DC module to switch to the discharging state so that the battery under test charges the energy storage battery. During the battery charging phase, the energy storage battery charges the battery under test for charging test. During the battery discharging phase, the battery under test charges the energy storage battery for discharging test. The electrical energy output by the battery under test can be recovered and reused, which can effectively improve the energy utilization rate of the battery testing process and reduce the battery testing cost.

[0049] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments provided herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the claims.

Claims

1. A battery testing circuit, characterized in that, It includes a control module, a bidirectional DC-DC module, a first connection module, and a second connection module. The first connection module is used to connect to the energy storage battery, and the second connection module is used to connect to the battery under test. The control terminal of the bidirectional DC-DC module is connected to the control module, the first connection terminal of the bidirectional DC-DC module is connected to the first connection module, and the second connection terminal of the bidirectional DC-DC module is connected to the second connection module. The control module is used to control the bidirectional DC-DC module to switch to a charging state during the battery charging phase of the battery under test, so that the energy storage battery charges the battery under test. The control module is also used to control the bidirectional DC-DC module to switch to a discharging state during the battery discharging phase of the battery under test, so that the battery under test charges the energy storage battery.

2. The battery testing circuit according to claim 1, characterized in that, The step of controlling the bidirectional DC-DC module to switch to a charging state so that the energy storage battery charges the battery under test includes: Control the bidirectional DC-DC module to switch to boost charging mode, so as to charge the battery under test after performing energy storage and boosting processing on the electrical energy provided by the energy storage battery; and / or The bidirectional DC-DC module is controlled to switch to buck charging mode so that the power supplied by the energy storage battery is stepped down before being used to charge the battery under test.

3. The battery testing circuit according to claim 1, characterized in that, The step of controlling the bidirectional DC-DC module to switch to a discharge state so that the battery under test can charge the energy storage battery includes: Control the bidirectional DC-DC module to switch to boost discharge mode, so as to charge the energy storage battery after performing energy storage boost processing on the electrical energy provided by the battery under test; and / or The bidirectional DC-DC module is controlled to switch to a step-down discharge state to step down the electrical energy provided by the battery under test before charging the energy storage battery.

4. The battery testing circuit according to claim 1, characterized in that, The bidirectional DC-DC module includes a DC-DC controller, an H-bridge circuit, and an energy storage circuit, wherein: The control input terminal of the DC-DC controller is connected to the control module, the control output terminal of the DC-DC controller is connected to the control terminal of the H-bridge circuit, and the energy storage circuit is connected in series between the midpoint of the first arm and the midpoint of the second arm of the H-bridge circuit. The first connection module is connected to the first arm of the H-bridge circuit, and the second connection module is connected to the second arm of the H-bridge circuit.

5. The battery testing circuit according to claim 4, characterized in that, In boost charging mode, the DC-DC controller controls the upper transistor of the first bridge arm and the lower transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can store the electrical energy provided by the energy storage battery, and controls the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can charge the battery under test. In buck charging mode, the DC-DC controller controls the upper transistors of the first and second bridge arms of the H-bridge circuit to conduct, so that the energy storage battery charges the battery under test through the energy storage circuit.

6. The battery testing circuit according to claim 4, characterized in that, In the boost discharge state, the DC-DC controller controls the lower transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can store the electrical energy provided by the battery under test, and controls the upper transistor of the first bridge arm and the upper transistor of the second bridge arm of the H-bridge circuit to conduct, so that the energy storage circuit can charge the energy storage battery. In the step-down discharge state, the DC-DC controller controls the upper transistors of the first and second bridge arms of the H-bridge circuit to conduct, so that the battery under test charges the energy storage battery through the energy storage circuit.

7. The battery testing circuit according to claim 4, characterized in that, The H-bridge circuit includes a first switch, a second switch, a third switch, and a fourth switch. The control terminals of the first switch, the second switch, the third switch, and the fourth switch are all connected to the control output terminal of the DC-DC controller. The first connection terminal of the first switching transistor is connected to the positive terminal of the second connection module, the second connection terminal of the first switching transistor is connected to the first connection terminal of the third switching transistor and the second connection terminal of the energy storage circuit, and the second connection terminal of the third switching transistor is connected to the negative terminal of the second connection module and the second connection terminal of the fourth switching transistor. The first connection terminal of the second switching transistor is connected to the positive terminal of the first connection module, the second connection terminal of the second switching transistor is connected to the first connection terminal of the fourth switching transistor and the first connection terminal of the energy storage circuit, and the second connection terminal of the fourth switching transistor is connected to the negative terminal of the first connection module.

8. The battery testing circuit according to any one of claims 1-7, characterized in that, It also includes a display module, which is connected to the control module, and the control module is used to control the display module to display battery test information.

9. A testing device, characterized in that, Includes the battery test circuit as described in any one of claims 1-8.

10. A testing system, characterized in that, It includes the testing equipment as described in claim 9 and a host computer, wherein the host computer is connected to the control module in the testing equipment.

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