Current flow direction switching circuit and current flow direction switching system

Abstract

The embodiment of the utility model discloses a current flow direction switching circuit and a current flow direction switching system, the current flow direction switching circuit comprises a switch module, the switch module is respectively connected with a unidirectional current module and a test module, and the switch module is used for switching the unidirectional current module and the test module under the condition that the test module is subjected to a charging test. A first path between the positive terminal of the unidirectional current module and the positive terminal of the test module is conducted, and a second path between the negative terminal of the test module and the negative terminal of the unidirectional current module is conducted. And the switch module is also used for conducting a third path between the positive electrode end of the unidirectional current module and the negative electrode end of the test module and conducting a fourth path between the positive electrode end of the test module and the negative electrode end of the unidirectional current module under the condition that the discharge test is carried out on the test module. Through the current flow direction switching circuit, the function of a bidirectional current source can be realized by using a unidirectional current module, the requirement of carrying out a charge and discharge test on the test module is met, and the test cost of the charge and discharge test is greatly saved.

Description

Technical Field

[0001] The present application relates to the field of bidirectional current technology, and in particular to a current flow direction switching circuit and a current flow direction switching system. Background Art

[0002] A bidirectional current source is a special power supply device that can provide current in two directions (forward and reverse) to achieve bidirectional conversion and exchange of electrical energy.

[0003] At present, during the charge and discharge test of a device, a bidirectional DC power supply is needed to simulate the charge and discharge process to test the relevant performance of the device during the charge and discharge process. However, the cost of the bidirectional DC source is very high, resulting in a high cost for the charge and discharge test. Utility Model Content

[0004] The embodiments of the present application disclose a current direction switching circuit and a current direction switching system, which can greatly reduce the cost of performing charge and discharge tests on a test module.

[0005] The present application embodiment discloses a current flow direction switching circuit, the current flow direction switching circuit comprising:

[0006] A switch module, the switch module is connected to the unidirectional current module and the test module respectively; the switch module is used to conduct a first path between the positive terminal of the unidirectional current module and the positive terminal of the test module, and conduct a second path between the negative terminal of the test module and the negative terminal of the unidirectional current module when the test module is charged.

[0007] The switch module is also used to conduct a third path between the positive terminal of the unidirectional current module and the negative terminal of the test module, and to conduct a fourth path between the positive terminal of the test module and the negative terminal of the unidirectional current module when a discharge test is performed on the test module.

[0008] As an optional implementation manner, the switch module is further used to disconnect the third path and the fourth path when the test module is subjected to a charging test;

[0009] The switch module is further used to disconnect the first path and the second path when a discharge test is performed on the test module.

[0010] As an optional implementation, the switch module includes:

[0011] A first switch unit, connected to the positive terminal of the unidirectional current module and the negative terminal of the test module respectively;

[0012] A second switch unit, connected to the positive terminal of the unidirectional current module and the positive terminal of the test module respectively;

[0013] a third switch unit, connected to the negative terminal of the unidirectional current module and the negative terminal of the test module respectively;

[0014] a fourth switch unit, connected to the negative terminal of the unidirectional current module and the positive terminal of the test module respectively;

[0015] When the test module is charged, the second switch unit and the third switch unit are in an on state, and the first switch unit and the fourth switch unit are in an off state, so as to connect the first path and the second path, and disconnect the third path and the fourth path;

[0016] When the test module is charged and tested, the first switch unit and the fourth switch unit are in an on state, and the second switch unit and the third switch unit are in an off state, so as to turn on the third path and the fourth path and turn off the first path and the second path.

[0017] As an optional implementation manner, the current direction switching circuit further includes a controller, and the controller is respectively connected to the first switch unit, the second switch unit, the third switch unit and the fourth switch unit;

[0018] The controller is used to control the second switch unit and the third switch unit to be turned on, and control the first switch unit and the fourth switch unit to be turned off when performing a charging test on the test module;

[0019] The controller is further used for controlling the first switch unit and the fourth switch unit to be turned on, and controlling the second switch unit and the third switch unit to be turned off when a discharge test is performed on the test module.

[0020] As an optional implementation, the target switch unit includes a trigger subunit and a relay subunit, and the trigger subunit is connected to the relay subunit; the target switch unit is any switch unit among the first switch unit, the second switch unit, the third switch unit and the fourth switch unit;

[0021] The trigger sub-unit is used to provide a driving electrical signal to the relay sub-unit when in a trigger state, and the driving electrical signal is used to drive the relay sub-unit to conduct, so as to conduct the path corresponding to the target switch unit.

[0022] As an optional implementation, the trigger subunit includes a button switch and an impedance element, the button switch and the impedance element are connected in series, a common end of the button switch and the impedance element is connected to the relay subunit, the button switch is connected to a first voltage end, the impedance element is connected to a second voltage end, and a first voltage of the first voltage end is different from a second voltage of the second voltage end;

[0023] When the trigger subunit is in a trigger state, the trigger subunit provides the first voltage to the relay subunit to drive the relay subunit to conduct;

[0024] When the trigger subunit is not in a trigger state, the impedance element provides the second voltage to the relay subunit to disconnect the relay subunit.

[0025] As an optional implementation, the relay subunit includes a relay and a triode, the relay includes a coil and a switching element coupled to the coil, and the triode is connected in series with the coil of the relay; wherein,

[0026] When the trigger subunit is in a trigger state, the switch element of the relay is turned on to turn on the path corresponding to the target switch unit;

[0027] When the trigger subunit is not in a trigger state, the switch element of the relay is disconnected to disconnect the path corresponding to the target switch unit.

[0028] As an optional embodiment, the relay electronic unit also includes a diode, which is connected in parallel with the coil of the relay. The diode is used to form a loop with the coil of the relay when the transistor is in a cut-off state to discharge the reverse electromotive force generated by the coil.

[0029] As an optional implementation, the current direction switching circuit further includes a first indication module and / or a second indication module; wherein,

[0030] The first indication module is used to be in a first indication state when a charging test is performed on the test module;

[0031] The second indication module is used to be in a second indication state when a discharge test is performed on the test module.

[0032] The embodiment of the present application discloses a current flow direction switching circuit, which is used to connect a unidirectional current module and a test module, and includes a first switch unit, a second switch unit, a third switch unit and a fourth switch unit, wherein the second switch unit is connected in series to a first path between a positive terminal of the unidirectional current module and a positive terminal of the test module, and the third switch unit is connected in series to a second path between a negative terminal of the test module and a negative terminal of the unidirectional current module; the first switch unit is connected in series to a third path between a positive terminal of the unidirectional current module and a negative terminal of the test module, and the fourth switch unit is connected in series to a fourth path between a positive terminal of the test module and a negative terminal of the unidirectional current module;

[0033] The target switch unit includes a first switch sub-unit and a second switch sub-unit connected to the first switch sub-unit, the second switch sub-unit is connected in series to the path corresponding to the target switch unit, and the second switch sub-unit is used to be turned on when the first switch sub-unit is in the on state, so as to turn on the path corresponding to the target switch unit; the target switch unit is any one of the first switch unit, the second switch unit, the third switch unit and the fourth switch unit.

[0034] The present application embodiment discloses a current flow direction switching system, including:

[0035] Unidirectional current module;

[0036] In any one of the current direction switching circuits disclosed in the embodiments of the present application, the switch module of the current direction switching circuit is respectively connected to the unidirectional current module and the test module.

[0037] Compared with the related art, the embodiments of the present application have the following beneficial effects:

[0038] An embodiment of the present application provides a current direction switching circuit and a current direction switching system, wherein the current direction switching circuit includes a switch module, which is respectively connected to a unidirectional current module and a test module. The switch module is used to, when performing a charging test on the test module, conduct a first path between the positive end of the unidirectional current module and the positive end of the test module, and conduct a second path between the negative end of the test module and the negative end of the unidirectional current module, so that the current output from the positive end of the unidirectional current module flows to the positive end of the test module, flows out from the negative end of the test module, and then flows to the negative end of the unidirectional DC source, thereby forming a charging circuit for the test module to realize a charging test on the test module. The switch module is also used to conduct the third path between the positive terminal of the unidirectional current module and the negative terminal of the test module, and conduct the fourth path between the positive terminal of the test module and the negative terminal of the unidirectional current module when the test module is subjected to a discharge test, so that the current output from the positive terminal of the unidirectional current module flows to the negative terminal of the test module, flows out from the positive terminal of the test module, and then flows to the negative terminal of the unidirectional DC source, forming a discharge loop of the test module to realize a charging test on the test module. The current flow switching circuit enables the unidirectional current module to realize the function of a bidirectional current source, meets the requirements for the charge and discharge test of the test module, and greatly saves the test cost of the charge and discharge test. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 It is a structural schematic diagram of a current flow direction switching circuit disclosed in an embodiment of the present application;

[0041] Figure 2 It is a structural schematic diagram of another current flow direction switching circuit disclosed in an embodiment of the present application;

[0042] Figure 3 It is a schematic diagram of a UI interface disclosed in an embodiment of the present application;

[0043] Figure 4a is a structural schematic diagram of a switch unit disclosed in an embodiment of the present application;

[0044] Figure 4b is a structural schematic diagram of another switch unit disclosed in an embodiment of the present application;

[0045] Figure 5aIt is a structural schematic diagram of a relay subunit disclosed in an embodiment of the present application;

[0046] Figure 5b is a schematic structural diagram of another relay subunit disclosed in an embodiment of the present application;

[0047] Figure 6 It is a structural schematic diagram of another current direction switching circuit disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0050] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0051] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0052] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0053] Energy storage technology is a hot topic in the field of new energy applications because it can apply technologies such as metal batteries, supercapacitors and flow batteries together with new energy. As the most important component in energy storage technology, the role of batteries in energy storage systems is crucial, especially when applied to power systems to more efficiently utilize electrical energy. BMS (Battery Management System) is an important part of the design of battery energy storage systems. BMS plays a sensing role in battery energy storage systems. Its main function is to monitor the operating status of each battery in the battery energy storage unit to ensure that the battery can operate safely. BMS measures the basic parameters of the battery, including voltage, current, temperature, etc., to prevent overcharging and over-discharging of the battery and extend the battery life.

[0054] Therefore, in order to ensure the safety and reliability of the energy storage system in energy storage technology, it is necessary to test the BMS board. In the process of testing the BMS board in the laboratory, it is necessary to realize the current forward and reverse switching (bidirectional control) to simulate the current during the battery charging and discharging process. The laboratory generally has two power supplies, namely a unidirectional current source and a bidirectional current source. The direction of the current output by the unidirectional current source always remains unchanged, that is, the unidirectional current source can only provide unidirectional current, while the bidirectional current source can provide current in both positive and negative directions, which is suitable for scenarios that require positive and reverse current control. Therefore, the laboratory uses a bidirectional current source to simulate the charging and discharging function to test the charging and discharging collection function of the BMS board, such as the collection accuracy of the charging and discharging current of the BMS board. However, the price of a bidirectional current source of the same brand specification can be as high as twice the price of a unidirectional current source, and the cost of using a bidirectional current source for charging and discharging equipment is high.

[0055] In view of this, an embodiment of the present application provides a current direction switching circuit and a current direction switching system. The current direction switching circuit can be respectively connected to a unidirectional current source and a test module that needs to be charged and discharged. The current direction switching circuit can convert the direction of the unidirectional current provided by the unidirectional current source to perform a charge and discharge test on the test module, thereby realizing the use of a unidirectional current source to perform a charge and discharge test on the test module, thereby greatly reducing the test cost of performing a charge and discharge test on the test module.

[0056] Please refer to Figure 1 , which shows a schematic diagram of the structure of a current flow switching circuit provided by an embodiment of the present application, such as Figure 1As shown, the current flow switching circuit may include a switch module 110, which is connected to the unidirectional current module 120 and the test module 130 respectively. The switch module 110 is used to conduct the first path L1 between the positive terminal V1 of the unidirectional current module and the positive terminal P1 of the test module, and conduct the second path L2 between the negative terminal P2 of the test module and the negative terminal V2 of the unidirectional current module when the test module 130 is charged. The switch module 110 is also used to conduct the third path L3 between the positive terminal V1 of the unidirectional current module and the negative terminal P2 of the test module, and conduct the fourth path L4 between the positive terminal P1 of the test module and the negative terminal V2 of the unidirectional current module when the test module 130 is discharged.

[0057] It should be noted that the unidirectional current module 120 can be used to provide a unidirectional current, such as the unidirectional current module may include one or more unidirectional current sources, and the current provided by the unidirectional current module 120 flows out from the positive terminal of the unidirectional current source and flows into the negative terminal of the unidirectional current source. The test module 130 is a module that needs to perform a charging test and a discharging test, such as a BMS board and an AC oscilloscope that need to perform a charging and discharging test, so as to test the performance of the test module 130, such as the current detection accuracy. When the test module 130 is performing a charging test, a forward current needs to be provided to the test module 130, that is, a current flowing from the positive terminal P1 of the test module to the negative terminal P2 of the test module is provided to detect the relevant performance of the test module 130 in collecting the forward current, such as the collection accuracy of the forward current and the forward voltage; when the test module 130 is performing a discharging test, a reverse current needs to be provided to the test module 130, that is, a current flowing from the negative terminal P2 of the test module to the positive terminal P1 of the test module is provided to detect the relevant performance of the test module 130 in collecting the reverse current, such as the collection accuracy of the reverse current and the reverse voltage.

[0058] The switch module 110 can be used to conduct the first path L1 between the positive terminal V1 of the unidirectional current module and the positive terminal P1 of the test module, and conduct the second path L2 between the negative terminal of the test module 130 and the negative terminal V2 of the unidirectional current module when performing a charging test on the test module 130. When the switch module 110 is connected to the unidirectional current module 120 and the test module 130, the current flows out from the positive terminal V1 of the unidirectional current module and flows to the positive terminal P1 of the test module through the first path L1. The current flows out from the negative terminal P2 of the test module and flows to the negative terminal V2 of the unidirectional current module through the second path L2, forming a charging circuit, providing a forward current for the test module 130, and realizing a charging test on the test module 130. The switch module 110 can also be used to conduct the third path L3 between the positive terminal V1 of the unidirectional current module and the negative terminal P2 of the test module, and conduct the fourth path L4 between the positive terminal P1 of the test module and the negative terminal V2 of the unidirectional current module when performing a discharge test on the test module 130. When the switch module 110 is connected to the unidirectional current module 120 and the test module 130, the current flows out from the positive terminal V1 of the unidirectional current module and flows to the negative terminal P2 of the test module through the third path L3. The current flows out from the positive terminal P1 of the test module and flows to the negative terminal V2 of the unidirectional current module through the fourth path L4, forming a charging loop, providing a reverse current for the test module 130, and realizing a discharge test on the test module 130.

[0059] In an embodiment of the present application, the switch module 110 can be connected to the unidirectional current module 120 and the test module 130 respectively. Through the switch module 110, there is no need to use a bidirectional current source. The unidirectional current provided by the unidirectional current module 120 (the current flowing from the positive terminal V1 of the unidirectional current module to the negative terminal V2 of the unidirectional current module) can be directly used to provide forward current and reverse current for the test module 130, thereby meeting the requirements for charging and discharging tests on the test module 130, and at the same time greatly reducing the cost of charging and discharging tests on the test module 130.

[0060] Optionally, the switch module 110 is also used to disconnect the third path L3 and the fourth path L4 when the test module 130 is subjected to a charging test. The switch module 110 is also used to disconnect the first path L1 and the second path L2 when the test module 130 is subjected to a discharging test, so that at the same time, only a forward current or a reverse current is provided to the test module 130, ensuring that the current flows to the switching circuit safely and reliably. Exemplarily, the switch module 110 is respectively connected to the positive terminal V1 of the unidirectional current module, the negative terminal V2 of the unidirectional current module, the positive terminal P1 of the test module, and the negative terminal P2 of the test module, and the switch module 110 can be used to selectively conduct the first path L1 and the second path L2, or selectively conduct the third path L3 and the fourth path L4. It should be noted that when the first path L1 is turned on and the second path L2 is turned on, the third path L3 is turned off and the fourth path L4 is turned off, so as to ensure that the current flowing through the test module 130 flows from the positive terminal P1 of the test module to the negative terminal P2 of the test module, thereby ensuring the reliability of the charging test of the test module 130. Similarly, when the third path L3 is turned on and the fourth path L4 is turned on, the second path L2 is turned off and the fourth path L4 is turned off, so as to ensure that the current flowing through the test module 130 flows from the negative terminal P2 of the test module to the positive terminal P1 of the test module, thereby ensuring the reliability of the discharge test of the test module 130.

[0061] Optionally, please continue to refer to Figure 1, the switch module 110 may include a double-pole double-throw switch, the double-pole double-throw switch includes a first end, a second end, a third end, a fourth end, a fifth end and a sixth end, and the double-pole double-throw switch can be used to selectively conduct the first end and the second end, and conduct the fourth end and the fifth end, or selectively conduct the first end and the third end, and conduct the fourth end and the sixth end. The first end of the double-pole double-throw switch is connected to the positive terminal V1 of the unidirectional current module, the second end of the double-pole double-throw switch is connected to the positive terminal P1 of the test module, the third end of the double-pole double-throw switch is connected to the negative terminal P2 of the test module, the fourth end of the double-pole double-throw switch is connected to the negative terminal V2 of the unidirectional current module, the fifth end of the double-pole double-throw switch is connected to the negative terminal P2 of the test module, and the sixth end of the double-pole double-throw switch is connected to the positive terminal P1 of the test module. In the case of a charging test on the test module 130, the double-pole double-throw switch can be controlled to conduct the first end and the second end, and conduct the fourth end and the fifth end, and at this time, the first end is disconnected from the third end, and the fourth end and the sixth end are disconnected, so as to ensure that the test module 130 receives a forward current. In the case of a discharge test on the test module 130, the double-pole double-throw switch can be controlled to selectively conduct the first end and the third end, and conduct the fourth end and the sixth end, and at this time, the first end is disconnected from the second end, and the fourth end and the fifth end are disconnected, so as to ensure that the test module 130 receives a reverse current. In this embodiment, by setting a double-pole double-throw switch, the unidirectional current provided by the unidirectional current module 120 can be used to perform a charge and discharge test on the test module 130, and the current flow switching circuit structure is simple, which further saves the cost of performing a charge and discharge test on the test module 130.

[0062] In an optional embodiment, if Figure 2As shown, the switch module 110 may further include a first switch unit 210 , a second switch unit 220 , a third switch unit 230 and a fourth switch unit 240 . Specifically, the first switch unit 210 is respectively connected to the positive terminal V1 of the unidirectional current module and the negative terminal P2 of the test module, the second switch unit 220 is respectively connected to the positive terminal V1 of the unidirectional current module and the positive terminal P1 of the test module, the third switch unit 230 is respectively connected to the negative terminal V2 of the unidirectional current module and the negative terminal P2 of the test module, and the fourth switch unit 240 is respectively connected to the negative terminal V2 of the unidirectional current module and the positive terminal P1 of the test module, that is, the first switch unit 210 is connected in series to the third path L3 between the positive terminal V1 of the unidirectional current module and the negative terminal P2 of the test module, the second switch unit 220 is connected in series to the first path L1 between the positive terminal V1 of the unidirectional current module and the positive terminal P1 of the test module, the third switch unit 230 is connected in series to the second path L2 between the negative terminal V2 of the unidirectional current module and the negative terminal P2 of the test module, and the fourth switch unit 240 is connected in series to the fourth path L4 between the negative terminal V2 of the unidirectional current module and the positive terminal P1 of the test module. The on / off states of each switch unit (the first switch unit 210, the second switch unit 220, the third switch unit 230, and the fourth switch unit 240) may include an on state and an off state. The first switch unit 210 is used to turn on or off the third path L3, the second switch unit 220 is used to turn on or off the first path L1, the third switch unit 230 is used to turn on or off the second path L2, and the fourth switch unit 240 is used to turn on or off the fourth path L4. In the case of performing a charging test on the test module 130, the second switch unit 220 and the third switch unit 230 are in the on state, and the first switch unit 210 and the fourth switch unit 240 are in the off state, so as to turn on the first path L1 and the second path L2, and turn off the third path L3 and the fourth path L4, so that the test module 130 can receive a forward current. When the test module 130 is charged, the first switch unit 210 and the fourth switch unit 240 are in the on state, and the second switch unit 220 and the third switch unit 230 are in the off state, so as to conduct the third path L3 and the fourth path L4, and disconnect the first path L1 and the second path L2, so that the test module 130 can receive the reverse current. In this embodiment, by setting four switch units, the four paths are turned on or off, the flexibility of the current flow switching circuit is improved, and the four switch units can select single-pole single-throw switches, and the structure of the current flow switching circuit is simple and low in cost.

[0063] When the test module 130 switches the test type, such as switching from a charging test to a discharging test, or switching from a discharging test to a charging test, the on-off state of each switch unit needs to be switched. For a switch unit whose switch type is a manual switch, such as a knob switch, a button switch, and a rocker switch, the on-off state of the switch unit can be switched by manual operation, such as rotating a knob on a knob switch, etc. For a switch unit whose switch type is an electrically controlled switch, such as a triode, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a relay, etc., different level signals can be provided to such switch units to control the on-off state of the electrically controlled switch unit. Exemplarily, the current flow switching circuit may also include a controller 250, which is connected to the first switch unit 210, the second switch unit 220, the third switch unit 230, and the fourth switch unit 240, respectively. The controller 250 is used to control the second switch unit 220 and the third switch unit 230 to be turned on, and the first switch unit 210 and the fourth switch unit 240 to be turned off, so that the test module 130 can receive a forward current when the test module 130 is subjected to a charging test. The controller 250 is also used to control the first switch unit 210 and the fourth switch unit 240 to be turned on, and the second switch unit 220 and the third switch unit 230 to be turned off, so that the test module 130 can receive a reverse current when the test module 130 is subjected to a discharge test. Exemplarily, the controller 250 may include an MCU (Microcontroller Unit), which may include four IO (Input / Outpu, input / output) interfaces, the four IO interfaces correspond to the four switch units one by one, and each IO interface is connected to the corresponding switch unit. The MCU may output a high level signal or a low level signal through the IO interface to control the on / off state of the switch unit. Exemplarily, when the switch unit is an NPN transistor, the IO interface of the MCU is connected to the base of the NPN transistor, and when the IO interface of the MCU outputs a high-level signal, the NPN transistor is in an on state, and when the IO interface of the MCU outputs a low-level signal, the NPN transistor is in an off state. In this embodiment, the on-off state of each switch unit can be adjusted by the controller 250, thereby improving the intelligence of the current flow switching circuit and reducing the labor cost of performing charge and discharge tests on the test module 130.

[0064] Optionally, the current flow switching circuit may also include a host computer, which is in communication with the controller 250. The host computer may include a display screen and an input device. The display screen can be used to display a UI (User Interface) interface. The input device is used to receive the control input of the tester. The host computer is used to send a control signal to the controller 250 according to the control input. The control signal is used to instruct the controller 250 to output a corresponding level signal from each IO interface to control the on / off state of each switch unit. Exemplarily, the input device may include but is not limited to a keyboard and a mouse. Optionally, please refer to Figure 3 , which shows a schematic diagram of an interface of a UI interface provided in an embodiment of the present application. The UI interface 300 may display a first control 310 corresponding to starting a charging test, and a second control 320 corresponding to starting a discharging test. The tester may trigger the first control 310 or the second control 320 through an input device. The host computer is used to output a first signal to the controller 250 when it is detected that the first control 310 is triggered. The first signal is used to instruct the controller 250 to control the second switch unit 220 and the third switch unit 230 to be turned on, and to control the first switch unit 210 and the fourth switch unit 240 to be turned off. The host computer is also used to output a second signal to the controller 250 when it is detected that the second control 320 is triggered. The second signal is used to instruct the controller 250 to control the first switch unit 210 and the fourth switch unit 240 to be turned on, and to control the second switch unit 220 and the third switch unit 230 to be turned off. In this embodiment, the unidirectional current module 120 is used to realize the bidirectional current source function through the host computer, the controller 250 and the switch module 110, which meets the charging and discharging test requirements, saves the test cost, and realizes automated testing, saving labor costs.

[0065] Optionally, the target switch unit may include a first switch subunit and a second switch subunit connected to the first switch subunit, the second switch subunit being connected in series to the path corresponding to the target switch unit, and the second switch subunit being used to be turned on when the first switch subunit is in the on state, so as to turn on the path corresponding to the target switch unit. Wherein, the target switch unit is any switch unit among the first switch unit 210, the second switch unit 220, the third switch unit 230 and the fourth switch unit 240, the second switch subunit of the first switch unit 210 is connected in series to the third path L3, the second switch subunit of the second switch unit 220 is connected in series to the first path L1, the second switch subunit of the third switch unit 230 is connected in series to the second path L2, and the second switch subunit of the fourth switch unit 240 is connected in series to the fourth path L4. Wherein, the on-off state of the first switch subunit may include an on state and an off state, and the second switch subunit is also used to be turned off when the first switch subunit is in the off state, so as to turn off the path corresponding to the target switch unit. The controller 250 can be connected to the first switch subunit of each switch unit respectively, and control the first switch subunit to be in the on state or the off state, so as to control the second switch subunit to be on or off, thereby turning on or off the path corresponding to the target switch unit. In this embodiment, by setting the first switch subunit and the second switch subunit, the control circuit (such as the controller 250) that controls the second switch subunit and the circuit (such as the first path L1, the second path L2, the third path L3 and the fourth path L3) that provides current to the test module are isolated from each other through the first switch subunit and the second switch subunit, so as to avoid the current used to test the test module from damaging the components of the control circuit, and improve the safety of the current flowing to the switching circuit.

[0066] Please continue to refer to Figure 3 , the host computer can also communicate with the test module 130 to obtain the test data of the test module 130 and display it on the UI interface 300, so that the tester can quickly determine the performance of the test module 130 and improve the human-computer interaction performance. Exemplarily, in the case of a charging test on a BMS board, the host computer can obtain the forward current value and forward voltage value collected by the BMS board and display them on the UI interface 300. In the case of a discharge test on a BMS board, the reverse current value and reverse voltage value collected by the BMS board can be obtained and displayed on the UI interface 300.

[0067] In an alternative embodiment, please continue to refer to Figure 2, the current flow switching circuit may further include a first indication module 260 and / or a second indication module 270. Specifically, the first indication module 260 is used to be in a first indication state when the test module 130 is subjected to a charging test. The second indication module 270 is used to be in a second indication state when the test module 130 is subjected to a discharge test. It should be noted that each indication module (including the first indication module 260 and the second indication module 270) has a different indication state, and each indication module is in a different indication state when the test module 130 is subjected to a charging test and a discharge test, so as to prompt the tester of the type of test being conducted by the test module 130. Optionally, the first indication module 260 is connected in series to the second path L2, and the first indication module 260 is used to be in a first indication state when a forward current flows through the first indication module 260. The second indication module 270 is connected in series to the fourth path L4, and the second indication module 270 is used to be in a second indication state when a reverse current flows through the second indication module 270. Exemplarily, the first indication module and / or the second indication module may include an indicator light, and the indication state may include an off state and a lit state. If the indicator light is a multi-color indicator light, the indication state may include various states corresponding to lights of different colors. It is understandable that the first indication state and the second indication state may be the same state or different states, and may be set according to actual needs. Exemplary, please continue to refer to Figure 2 , the first indication module 260 includes a first indicator light D1, and the second indication module 270 includes a second indicator light D2, and the first indication state and the second indication state may both be in a lit state. In the case of a charging test on the test module 130, a forward current flows through the first indication module 260, the first indicator light D1 is in a lit state, the second indicator light D2 does not receive the current, and the second indicator light D2 is in an off state. In the case of a discharge test on the test module 130, a reverse current flows through the second indicator light D2, the second indicator light D2 is in a lit state, the first indicator light D1 does not receive the current, and the first indicator light D1 is in an off state. Optionally, the first indicator light D1 and / or the second indicator light D2 may include a light emitting diode. In this embodiment, the first indicator light D1 is connected in series to the second path L2 and / or the second indicator light D2 is connected in series to the fourth path L4, so that the on and off state (lit state and off state) of the first indicator light D1 is associated with whether the test module 130 receives a forward current, and the on and off state of the second indicator light D2 is associated with whether the test module 130 receives a reverse current. By setting the first indicator light D1 and the second indicator light D2, the current received by the test module 130 can be accurately indicated, which is convenient for testers to determine whether the test module 130 is performing a charge and discharge test, and the type of test being performed.

[0068] In this embodiment, a first indication module 260 and / or a second indication module 270 are provided to indicate the type of test being performed by the test module 130, thereby facilitating the tester to determine the test currently being performed and improving the human-computer interaction performance of the current flow switching circuit.

[0069] Please refer to Figure 4a to Figure 4b , shows a schematic diagram of the structure of the switch unit provided in an embodiment of the present application, such as Figure 4a to Figure 4b As shown, the target switch unit may include a trigger subunit 410 and a relay subunit 420, and the trigger subunit 410 and the relay subunit 420 are connected. The trigger subunit 410 is used to provide a driving electrical signal to the relay subunit 420 when it is in a triggered state. It should be noted that the target switch unit in this embodiment may be any switch unit among the first switch unit 210, the second switch unit 220, the third switch unit 230 and the fourth switch unit 240, and the driving electrical signal is used to drive the relay subunit 420 to conduct, so as to conduct the path corresponding to the target switch unit. The trigger subunit 410 can also be used to provide a cut-off electrical signal to the relay subunit 420 when it is not in a triggered state, and the cut-off electrical signal can be used to control the relay subunit 420 to disconnect, so as to disconnect the path corresponding to the target switch unit. The relay subunit 420 can be connected in series to the path corresponding to the target switch unit, such as the relay subunit 420 of the first switch unit 210 is connected in series to the third path L3, that is, the first end A of the relay subunit 420 is connected to the positive terminal V1 of the unidirectional current module, and the second end B of the relay subunit 420 is connected to the negative terminal V2 of the unidirectional current module. When the relay subunit 420 is turned on, the path corresponding to the target switch unit is turned on, and when the relay subunit 420 is turned off, the path corresponding to the target switch unit is turned off. By controlling the state of the trigger subunit 410, the relay subunit 420 is controlled to be turned on and off, thereby controlling the path corresponding to the target switch unit to be turned on. In the case where the trigger subunit 410 is a manual operation unit, the tester can manually operate the trigger subunit 410 to make it in a triggered state or not in a triggered state, so as to turn the relay subunit 420 on or off. Exemplarily, the trigger subunit 410 may include but is not limited to a button switch, a knob switch and a rocker switch. For the button switch, the button switch may include a pressed state and a released state. If the button switch is in a pressed state and the relay electronic unit 420 is turned on, the trigger subunit 410 is in a triggered state, including the button switch being in a pressed state.

[0070] Please continue to refer to Figure 4a to Figure 4b, for the electric switch, by providing different signals to the third terminal C of the relay sub-unit 420, the relay sub-unit 420 can be driven to be turned on or off. Optionally, the trigger sub-unit 410 may include a button switch K1 and an impedance element R1. The button switch K1 is connected in series with the impedance element R1, the common end of the button switch K1 and the impedance element R1 is connected to the relay sub-unit 420, the button switch K1 is connected to the first voltage end, the impedance element R1 is connected to the second voltage end, and the first voltage of the first voltage end is different from the second voltage of the second voltage end. Wherein, when the trigger sub-unit 410 is in a triggered state, the trigger sub-unit 410 provides the first voltage to the relay sub-unit 420 to drive the relay sub-unit 420 to be turned on. When the trigger sub-unit 410 is not in a triggered state, the impedance element R1 provides the second voltage to the relay sub-unit 420 to disconnect the relay sub-unit 420.

[0071] It should be noted that the impedance element R1 may include one or more resistors. The voltage at the common end of the button switch K1 and the impedance element R1 may be used as an electrical signal provided by the trigger subunit 410 to the relay subunit 420. The appropriate first voltage and second voltage may be selected according to the type of the selected relay subunit 420. The trigger subunit 410 is in a triggered state, including the button switch K1 being in a pressed state, and the trigger subunit 410 is not in a triggered state, including the button switch K1 being in a released state. In an optional embodiment, if the relay subunit 420 is turned on when a low-level signal is received and is turned off when a high-level signal is received, the second voltage should be selected to be greater than the first voltage. Figure 4a As shown, the first voltage terminal may be the ground terminal GND, the second voltage terminal may be the power supply terminal VCC, and the voltage of the second voltage may be 24V. It should be noted that when the button switch K1 is in a pressed state, the third terminal C of the relay sub-unit is connected to the ground terminal GND, and the voltage of the third terminal C of the relay sub-unit is consistent with the voltage of the ground terminal GND, that is, a low-level signal is received and the relay sub-unit 420 is turned on. When the button switch K1 is in a released state, the third terminal C of the relay sub-unit is not conductive to the ground terminal GND, and the voltage of the third terminal C of the relay sub-unit is consistent with the voltage of the power supply terminal VCC, that is, a high-level signal is received and the relay sub-unit 420 is disconnected. In another optional embodiment, if the relay sub-unit 420 is turned on when a high-level signal is received and is disconnected when a low-level signal is received, the first voltage should be selected to be greater than the second voltage. Figure 4bAs shown, the first voltage terminal is the power terminal VCC, and the second voltage terminal is the ground terminal GND. The first voltage may be 24V. It should be noted that when the button switch K1 is in a pressed state, the third terminal C of the relay subunit is connected to the power terminal VCC, and the voltage of the third terminal C of the relay subunit is consistent with the voltage of the power terminal VCC, that is, a high level signal is received, and the relay subunit 420 is turned on. When the button switch K1 is in a released state, the third terminal C of the relay subunit is not conductive with the power terminal VCC, and the voltage of the third terminal C of the relay subunit is consistent with the voltage of the ground terminal GND, that is, a low level signal is received, and the relay subunit 420 is disconnected.

[0072] In this embodiment, the function of a bidirectional current source can be realized by using the impedance element R1 and the button switch K1 and the unidirectional current module 120 to meet the charging and discharging test requirements. At the same time, the impedance element R1 and the button switch K1 are low in cost, further reducing the cost of the current flow switching circuit.

[0073] It is understandable that the types of the relay subunit 420 and the trigger subunit 410 can be reasonably selected so that when the trigger subunit 410 is not in the trigger state, a driving electrical signal is provided to the relay subunit 420. When the trigger subunit 410 is in the trigger state, a cutoff electrical signal is provided to the relay subunit 420. The specific circuit structure can be set with reference to the above embodiment.

[0074] In this embodiment, by setting a switch unit including a trigger sub-unit 410 and a relay sub-unit 420, the conduction and disconnection of the relay sub-unit 420 can be controlled by adjusting the state of the trigger sub-unit 410, so as to provide forward current and reverse current for the test module 130, so that the function of a bidirectional current source can be realized by utilizing the unidirectional current module 120, thereby saving costs while meeting the requirements of charge and discharge tests.

[0075] When the test module 130 is subjected to a charge and discharge test (charge test or discharge test), the current flowing through the test module 130 may be as high as several hundred A. In order to improve the safety of the current flowing to the switching circuit, the present embodiment provides a structure of the relay subunit 420. Please refer to Figure 5a to Figure 5b, the relay subunit 420 may include a relay RL and a transistor Q1. Specifically, the relay RL includes a coil and a switching element coupled to the coil. The transistor Q1 is connected in series with the coil of the relay RL. When the trigger subunit 410 is in a triggered state, the switching element of the relay RL is turned on to turn on the path corresponding to the target switch unit. When the trigger subunit 410 is not in a triggered state, the switching element of the relay RL is turned off to disconnect the path of the target switch unit. It should be noted that the first switch subunit described in the above embodiment may include the transistor Q1, and the second switch subunit may include the relay RL. The switching element of the relay RL is connected in series with the path corresponding to the target switch unit. The transistor Q1 may be an NPN transistor (such as Figure 5b as shown) or a PNP transistor (as Figure 5a As shown in FIG. 1 , the switch element of the relay RL may include a normally open contact and a normally closed contact. It is understandable that the normally open contact is a contact group that is in an open state when the coil of the relay RL is not energized, and is in a closed state when the coil of the relay RL is energized, and the normally closed contact is a contact group that is in a closed state when the coil of the relay RL is not energized, and is in an open state when the coil of the relay RL is energized. The transistor Q1 can be connected in series to the power supply circuit of the coil. When the transistor Q1 is in the cut-off state, the coil is not energized, the normally open contact is disconnected, and the normally closed contact is closed. When the transistor Q1 is in the on state, the coil is energized, the normally open contact is closed, and the normally closed contact is disconnected.

[0076] In an alternative embodiment, please refer to Figure 5a , transistor Q1 is a PNP transistor, the switch element of the relay RL is a normally open contact, the driving electrical signal can be a low-level signal, the trigger subunit 410 is connected to the base of the PNP transistor, the emitter of the PNP transistor is connected to the power supply terminal VCC, and the coil is connected to the collector of the PNP transistor and the ground terminal GND respectively. When the base of the PNP transistor receives a low-level signal, the PNP transistor is turned on, the coil is energized, the normally open contact of the relay RL is closed, and the path corresponding to the target switch unit is turned on.

[0077] In another optional embodiment, please refer to Figure 5b , the transistor Q1 includes an NPN transistor, the switch element of the relay RL is a normally open contact, the driving electrical signal can be a high-level signal, the trigger subunit 410 is connected to the base of the NPN transistor, the emitter of the NPN transistor is connected to the ground terminal GND, and the coil is connected to the collector of the NPN transistor and the power supply terminal VCC respectively. When the base of the NPN transistor receives a high-level signal, the NPN transistor is turned on, the coil is energized, the normally open contact of the relay RL is closed, and the path corresponding to the target switch unit is turned on.

[0078] In this embodiment, the relay sub-unit 420 includes a transistor Q1 and a relay RL. The relay RL plays an isolating role in the circuit, and controls the flow direction of the large current input to the test module 130 through the small current trigger sub-unit 410 (the current flowing through the trigger sub-unit 410 is about tens of milliamperes). The relay sub-unit 420 provides the test module 130 with currents of different directions (conversion function) while also improving the safety of the current direction switching circuit.

[0079] Optionally, please continue to refer to Figure 5a to Figure 5b , the relay subunit 420 may also include a diode D3, which is connected in parallel with the coil of the relay RL. The diode D3 is used to form a loop with the coil of the relay RL when the transistor Q1 is in the off state (disconnected state) to discharge the reverse electromotive force generated by the coil. It should be noted that the coil can store energy. When the transistor Q1 is in the off state, the coil is powered off, and a large reverse electromotive force will be generated at both ends of the coil, which may damage the coil or cause the components connected to the coil to break down. By connecting the diode D3 at both ends of the coil, the coil and the diode D3 form a loop, and the energy stored in the coil can be discharged through the loop. The diode D3 plays a role of freewheeling here, and can prevent the transistor Q1 from being broken down, thereby protecting the transistor Q1. Specifically, the positive pole of the diode D3 is connected to the current inflow end when the coil is powered on, and the negative pole of the diode D3 is connected to the current outflow end when the coil is powered on.

[0080] Optionally, please continue to refer to Figure 5a to Figure 5b , the relay subunit 420 may also include a first resistor R2. The first resistor R2 is connected to the base of the transistor Q1 to limit the base current of the transistor Q1 so that the base current of the transistor Q1 is maintained within an appropriate range to ensure the normal operation of the transistor Q1 and reduce the power consumption of the transistor Q1. Optionally, the resistance range of the first resistor R2 includes 0.5kΩ (kilo-ohm) to 1.5kΩ. Optionally, the resistance of the first resistor R2 is 0.5kΩ, 1.kΩ or 1.5kΩ.

[0081] Optionally, please continue to refer to Figure 5a to Figure 5b , the relay subunit 420 may further include a second resistor R3. One end of the second resistor R3 is connected to the base of the transistor Q1, and the other end of the second resistor R3 is connected to the emitter of the transistor Q1, so that the transistor Q1 can reliably operate in a cut-off state or a saturated state, so that the voltage of the relay RL is stable. Optionally, the resistance range of the second resistor R3 includes 4.3KΩ to 5.1KΩ. Optionally, the resistance of the second resistor R3 is 4.3KΩ, 4.5K, 4.7KΩ, 4.9KΩ or 5.1KΩ.

[0082] Please refer to Figure 6, which shows a structural schematic diagram of another current flow switching circuit provided by an embodiment of the present application, such as Figure 6 As shown, the current flow switching circuit may include four switch units, which are respectively a first switch unit 210, a second switch unit 220, a third switch unit 230 and a fourth switch unit 240. Each switch unit includes a relay RL, a PNP transistor Q2, a first resistor R2, a second resistor R3 and a diode D3. Specifically, the coil of the relay RL is respectively connected to the ground terminal GND and the collector of the PNP transistor Q2, the emitter of the PNP transistor Q2 is connected to the power supply terminal VCC, the base of the PNP transistor Q2 is connected to the first end of the first resistor R2, the second resistor R3 is respectively connected to the emitter and the base of the PNP transistor Q2, the switching elements of the relay RL of the first switch unit 210 are respectively connected to the positive terminal V1 of the unidirectional current module and the negative terminal P2 of the test module, the switching elements of the relay RL of the second switch unit 220 are respectively connected to the positive terminal V1 of the unidirectional current module and the positive terminal P1 of the test module, the switching elements of the relay RL of the third switch unit 230 are respectively connected to the negative terminal V2 of the unidirectional current module and the negative terminal P2 of the test module, and the switching elements of the relay RL of the fourth switch unit 240 are respectively connected to the negative terminal V2 of the unidirectional current module and the positive terminal P1 of the test module. In this embodiment, the switch elements of the relay RL are all normally open contacts. Different level signals can be provided to the second end of the first resistor R2 of each switch unit to control the switching element of the corresponding relay RL to be turned on and off, thereby controlling the corresponding path to be turned on and off. The following provides two methods for providing different level signals to the second end of the first resistor R2.

[0083] In an alternative embodiment, please continue to refer to Figure 6, each switch unit may also include an impedance element R1 and a button switch K1. Specifically, the impedance element R1 is connected to the power supply terminal VCC and the second end of the first resistor R2, respectively, and the button switch K1 is connected to the second end of the first resistor R2 and the ground terminal GND, respectively. In the case of charging test on the test module 130, the button switch K1 of the first switch unit 210 and the button switch K1 of the fourth switch unit 240 are manually controlled to be disconnected, and the button switch K1 of the second switch unit 220 and the button switch K1 of the third switch unit 230 are manually pressed, and the relay RL of the first switch unit 210 and the relay RL of the fourth switch unit 240 are not turned on, and the relay RL of the second switch unit 220 and the relay RL of the third switch unit 230 are closed and turned on. In this case, the current flows from the positive terminal V1 of the unidirectional current module to the relay RL of the second switch unit 220, and then flows to the positive terminal P1 of the test module, and then flows out from the negative terminal P2 of the test module, and flows to the relay RL of the third switch unit 230, until it flows into the negative terminal V2 of the unidirectional current module, forming a charging circuit. When the test module 130 is subjected to a discharge test, the button switch K1 of the first switch unit 210 and the button switch K1 of the fourth switch unit 240 are manually pressed, the button switch K1 of the second switch unit 220 and the button switch K1 of the third switch unit 230 are manually controlled to be disconnected, the relay RL of the first switch unit 210 and the relay RL of the fourth switch unit 240 are closed and turned on, and the relay RL of the second switch unit 220 and the relay RL of the third switch unit 230 are not turned on. In this case, the current flows from the positive terminal V1 of the unidirectional current module to the relay RL of the first switch unit 210, and flows to the negative terminal P2 of the test module. The current flows out from the positive terminal P1 of the test module, flows to the relay RL of the fourth switch unit 240, and finally flows into the negative terminal V2 of the unidirectional current module, forming a discharge loop. In this embodiment, a unidirectional current source is used to realize the bidirectional current source function through the button switch K1, which meets the requirements of the charge and discharge test and saves costs.

[0084] In another optional embodiment, the current flow switching circuit may further include a controller 250, and the second end of the first resistor R2 of each switch unit is respectively connected to the output interface (such as IO interface) of the controller 250. In the case of charging test on the test module 130, the controller 250 provides a high level signal to the second end of the first resistor R2 of the first switch unit 210 and the fourth switch unit 240, and provides a low level signal to the second end of the first resistor R2 of the second switch unit 220 and the third switch unit 230, so that the relay RL of the first switch unit 210 and the fourth switch unit 240 is not turned on, and the relay RL of the second switch unit 220 and the third switch unit 230 is closed and turned on. In this case, the current flows from the positive terminal V1 of the unidirectional current module to the relay RL of the second switch unit 220, and then flows to the positive terminal P1 of the test module, and then flows out from the negative terminal P2 of the test module, and flows to the relay RL of the third switch unit 230, until it flows into the negative terminal V2 of the unidirectional current module, forming a charging loop. In the case of a discharge test on the test module 130, the controller 250 provides a low-level signal to the second end of the first resistor R2 of the first switch unit 210 and the fourth switch unit 240, and provides a high-level signal to the second end of the first resistor R2 of the second switch unit 220 and the third switch unit 230, so that the relay RL of the first switch unit 210 and the fourth switch unit 240 is closed and turned on, and the relay RL of the second switch unit 220 and the third switch unit 230 is not turned on. In this case, the current flows from the positive terminal V1 of the unidirectional current module to the relay RL of the first switch unit 210, and flows to the negative terminal P2 of the test module. The current flows out from the positive terminal P1 of the test module, flows to the relay RL of the fourth switch unit 240, and finally flows into the negative terminal V2 of the unidirectional current module to form a discharge loop. In this embodiment, a unidirectional current module 120 is used to realize the bidirectional current source function through the current flow switching circuit, meet the test requirements, save costs, and realize the bidirectional flow function through the controller 250, reducing the labor cost of the charge and discharge test.

[0085] The present application also provides a current flow switching system. Figure 1 The current direction switching system includes any one of the current direction switching circuits and the unidirectional current module 120 provided in the above embodiments. For the connection structure between the current direction switching circuit and the unidirectional current module 120, please refer to the above embodiments, which will not be repeated here.

[0086] The current flow direction switching system provided in the embodiment of the present application connects the unidirectional current module 120 to the current flow direction switching circuit, and the current flow direction switching circuit includes a switch module 110. The switch module 110 is connected to the unidirectional current module 120. After the test module 130 is connected to the current flow direction switching system, when the test module 130 is charged, the switch module 110 conducts the first path L1 between the positive terminal V1 of the unidirectional current module and the positive terminal P1 of the test module, and conducts the second path L2 between the negative terminal P2 of the test module and the negative terminal V2 of the unidirectional current module, so that the current output from the positive terminal V1 of the unidirectional current module flows to the positive terminal P1 of the test module, flows out from the negative terminal P2 of the test module, and then flows to the negative terminal of the unidirectional current source, forming a charging circuit of the test module 130, so as to realize the charging test of the test module 130. When the test module 130 is subjected to a discharge test, the switch module 110 switches on the third path L3 between the positive terminal V1 of the unidirectional current module and the negative terminal P2 of the test module, and switches on the fourth path L4 between the positive terminal P1 of the test module and the negative terminal V2 of the unidirectional current module, so that the current output from the positive terminal V1 of the unidirectional current module flows to the negative terminal P2 of the test module, flows out from the positive terminal P1 of the test module, and then flows to the negative terminal of the unidirectional current source, forming a discharge loop of the test module 130, so as to realize a charging test on the test module 130. The current flow direction switching system provided in this embodiment utilizes the unidirectional current module 120 to realize the function of a bidirectional current source, and while meeting the requirements for performing a charge and discharge test on the test module 130, it greatly saves the test cost of the charge and discharge test.

[0087] In the description of this specification, the descriptions with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc., mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0088] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A current flow switching circuit, characterized in that: The current flow switching circuit comprises: A switch module, the switch module is connected to the unidirectional current module and the test module respectively; the switch module is used to conduct a first path between the positive terminal of the unidirectional current module and the positive terminal of the test module, and conduct a second path between the negative terminal of the test module and the negative terminal of the unidirectional current module when the test module is charged. The switch module is also used to conduct a third path between the positive terminal of the unidirectional current module and the negative terminal of the test module, and to conduct a fourth path between the positive terminal of the test module and the negative terminal of the unidirectional current module when a discharge test is performed on the test module.

2. The current flow switching circuit according to claim 1, characterized in that: The switch module is further used to disconnect the third path and the fourth path when the test module is subjected to a charging test; The switch module is further used to disconnect the first path and the second path when a discharge test is performed on the test module.

3. The current flow switching circuit according to claim 1 or 2, characterized in that: The switch module comprises: A first switch unit, connected to the positive terminal of the unidirectional current module and the negative terminal of the test module respectively; A second switch unit, connected to the positive terminal of the unidirectional current module and the positive terminal of the test module respectively; a third switch unit, connected to the negative terminal of the unidirectional current module and the negative terminal of the test module respectively; a fourth switch unit, connected to the negative terminal of the unidirectional current module and the positive terminal of the test module respectively; When the test module is charged, the second switch unit and the third switch unit are in an on state, and the first switch unit and the fourth switch unit are in an off state, so as to connect the first path and the second path, and disconnect the third path and the fourth path; When the test module is charged and tested, the first switch unit and the fourth switch unit are in an on state, and the second switch unit and the third switch unit are in an off state, so as to turn on the third path and the fourth path and turn off the first path and the second path.

4. The current flow switching circuit according to claim 3, characterized in that: The current flow switching circuit further includes a controller, wherein the controller is respectively connected to the first switch unit, the second switch unit, the third switch unit and the fourth switch unit; The controller is used to control the second switch unit and the third switch unit to be turned on, and control the first switch unit and the fourth switch unit to be turned off when performing a charging test on the test module; The controller is further used for controlling the first switch unit and the fourth switch unit to be turned on, and controlling the second switch unit and the third switch unit to be turned off when a discharge test is performed on the test module.

5. The current flow switching circuit according to claim 3, characterized in that: The target switch unit includes a trigger subunit and a relay subunit, and the trigger subunit is connected to the relay subunit; the target switch unit is any switch unit among the first switch unit, the second switch unit, the third switch unit and the fourth switch unit; The trigger sub-unit is used to provide a driving electrical signal to the relay sub-unit when in a trigger state, and the driving electrical signal is used to drive the relay sub-unit to conduct, so as to conduct the path corresponding to the target switch unit.

6. The current flow switching circuit according to claim 5, characterized in that: The trigger subunit includes a button switch and an impedance element, the button switch and the impedance element are connected in series, a common end of the button switch and the impedance element is connected to the relay subunit, the button switch is connected to a first voltage end, the impedance element is connected to a second voltage end, and a first voltage of the first voltage end is different from a second voltage of the second voltage end; When the trigger subunit is in a trigger state, the trigger subunit provides the first voltage to the relay subunit to drive the relay subunit to conduct; When the trigger subunit is not in a trigger state, the impedance element provides the second voltage to the relay subunit to disconnect the relay subunit.

7. The current flow switching circuit according to claim 5, characterized in that: The relay subunit includes a relay and a triode, the relay includes a coil and a switch element coupled to the coil, and the triode is connected in series with the coil of the relay; wherein, When the trigger subunit is in a trigger state, the switch element of the relay is turned on to turn on the path corresponding to the target switch unit; When the trigger subunit is not in a trigger state, the switch element of the relay is disconnected to disconnect the path corresponding to the target switch unit.

8. The current flow switching circuit according to claim 7, characterized in that: The relay subunit further includes a diode, which is connected in parallel with the coil of the relay. The diode is used to form a loop with the coil of the relay when the transistor is in a cut-off state to discharge the reverse electromotive force generated by the coil.

9. A current flow switching circuit, characterized in that: The current direction switching circuit is used to connect the unidirectional current module and the test module, and the current direction switching circuit includes a first switch unit, a second switch unit, a third switch unit and a fourth switch unit, wherein the second switch unit is connected in series to a first path between the positive terminal of the unidirectional current module and the positive terminal of the test module, and the third switch unit is connected in series to a second path between the negative terminal of the test module and the negative terminal of the unidirectional current module; the first switch unit is connected in series to a third path between the positive terminal of the unidirectional current module and the negative terminal of the test module, and the fourth switch unit is connected in series to a fourth path between the positive terminal of the test module and the negative terminal of the unidirectional current module; The target switch unit includes a first switch sub-unit and a second switch sub-unit connected to the first switch sub-unit, the second switch sub-unit is connected in series to the path corresponding to the target switch unit, and the second switch sub-unit is used to be turned on when the first switch sub-unit is in the on state, so as to turn on the path corresponding to the target switch unit; the target switch unit is any one of the first switch unit, the second switch unit, the third switch unit and the fourth switch unit.

10. A current flow switching system, characterized in that: include: Unidirectional current module; According to the current direction switching circuit as described in any one of claims 1 to 9, the switch module of the current direction switching circuit is respectively connected to the unidirectional current module and the test module.

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