An electric vehicle power battery charge and discharge detection device

Abstract

The present invention discloses a charging and discharging detection device for an electric vehicle power battery. The device includes a detection connection plug and a detection unit; the detection connection plug is connected to the detection unit through a connection wire harness; the detection connection plug is matched with a DC charging socket of the electric vehicle; by inserting the detection plug into the DC charging socket of the electric vehicle, the detection unit can be electrically connected to the power battery of the electric vehicle, thereby realizing direct charging and discharging tests on the power battery. In the present invention, charging and discharging tests can be carried out without disassembling the power battery of the electric vehicle, simplifying the test process; two-way communication can be carried out through the CAN communication function, and the test results can be fed back to the power battery, facilitating the electric vehicle to correct the power battery parameters; at the same time, the charging and discharging states are independently confirmed by means of resistance, avoiding damage to the battery caused by incorrect settings or operations, and increasing the safety and reliability of the system.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicle power battery detection, and more particularly to a charging and discharging detection device for an electric vehicle power battery. Background Art

[0002] As one of the key components of electric vehicles, the power battery provides the power source for electric vehicles, and its electrical performance directly affects the power performance, comfort and safety of the whole vehicle. The electrical performance parameters of the power battery mainly include capacity, internal resistance, power, charging rate, etc., and their values are mainly measured by a charging and discharging detection device. Existing charging and discharging detection devices generally do not include a state control unit and a detection connection plug. When testing the electrical performance of an electric vehicle power battery, only the positive and negative poles of the detection device are mechanically connected to the positive and negative poles of the battery through bolts or simple plugs, and then the connection reliability is manually checked and the detection state and test parameters are manually set; especially for the test of the electrical performance of the power battery that has been installed on the vehicle, the power battery or / and the high-voltage wire harness need to be disassembled and then connected to the charging and discharging detection device before testing, and the test process requires complex settings, which is time-consuming and laborious. Therefore, there is an urgent need for a charging and discharging detection device for an electric vehicle power battery that can quickly detect the power battery loaded on an electric vehicle through a DC charging socket without disassembling the power battery or / and the high-voltage wire harness, especially can automatically detect or set the detection state and automatically set the test parameters according to the detection state, and can feedback the test results to the electric vehicle or the power battery, facilitating the electric vehicle to correct or measure the operating parameters of the power battery. Summary of the Invention

[0003] In view of the above-mentioned technical problems, the present invention provides a charging and discharging detection device for an electric vehicle power battery, which is connected to the DC charging interface of the electric vehicle through a detection connection plug, and uses a state control unit to guide the battery into the detection state. At the same time, two-way communication is carried out through the CAN communication function to complete the setting of test parameters and feedback the test results to the power battery. The technical means adopted by the present invention are as follows.

[0004] A charging and discharging detection device for an electric vehicle power battery, characterized in that: the device includes a detection connection plug and a detection unit; the detection connection plug is connected to the detection unit through a connection wire harness; the detection connection plug is matched with the DC charging socket of the electric vehicle and at least includes a battery positive connection terminal, a battery negative connection terminal, a body ground connection terminal, a detection state signal connection terminal, a CAN communication positive connection terminal, and a CAN communication negative connection terminal; the detection unit includes a human-machine interaction unit, a detection control unit, a state control unit, and a charging and discharging unit.

[0005] Preferably, the state control unit includes a detection device ground terminal, a first state resistor, a second state resistor, a first state switch, and a second state switch; one end of the first state resistor is electrically connected to the detection device ground terminal, and the other end is electrically connected to the detection state signal connection terminal through the first state switch; one end of the second state resistor is electrically connected to the detection device ground terminal, and the other end is electrically connected to the detection state signal connection terminal through the second state switch; the control ends of the first state switch and the second state switch are respectively electrically connected to the detection control unit.

[0006] Preferably, the detection control unit can control the charge and discharge unit to be in a charging state, a discharging state, a charge and discharge state, a stop state, or any other defined state according to the resistance value or / and the periodic change frequency value of the resistance between the detection device ground terminal and the detection state signal connection terminal.

[0007] The key point of the design of the present invention is that when the charge and discharge unit is in the charging state, the detection device only performs a charging operation on the battery; when the charge and discharge unit is in the discharging state, the detection device only performs a discharging operation on the power battery; when the charge and discharge unit is in the charge and discharge state, the detection device can perform a charging or discharging operation on the power battery; when the charge and discharge unit is in the stop state, the detection device will not perform any operation on the power battery; when the charge and discharge unit is in other defined states, such as: a fault state, a completion state, etc., the detection device will perform corresponding operations on the power battery. By setting the first state resistor and the second state resistor to different resistance values, and controlling the periodic closing and opening of the first state switch and the second state switch, the resistance value between the detection device ground terminal and the detection state signal connection terminal will change with different resistances or / and frequencies, defining different resistances or / and resistance change frequencies corresponding to each defined state. Then, each state can be distinguished according to different resistances or / and resistance change frequencies. For example, if the first state resistor is selected as 1 kΩ and the second state resistor is selected as 2 kΩ, and the first state switch is only closed, the second state switch is only closed, the first state switch and the second state switch are closed simultaneously, the second state switch is normally closed and the first state switch is closed and opened at 50 Hz, and the first state switch is normally closed and the second state switch is closed and opened at 50 Hz are respectively set, then 1 kΩ, 2 kΩ, 2 / 3 kΩ, 2 kΩ and 2 / 3 kΩ 50 Hz change, 1 kΩ and 2 / 3 kΩ 50 Hz change can be obtained between the detection device ground terminal and the detection state signal connection terminal respectively, so that 5 different resistance state values can be defined to correspond to 5 states of the charge and discharge unit. When the detection device of the present invention performs actual detection, the external battery to be detected can also monitor this resistance value through the detection state signal connection terminal, and then determine the current state of the detection device.

[0008] Preferably, the positive connection terminal of the battery is electrically connected to the positive electrode of the charge and discharge unit through a wire; the negative connection terminal of the battery is electrically connected to the negative electrode of the charge and discharge unit through a wire; the body ground connection terminal is electrically connected to the grounding terminal of the detection device through a wire; the detection status signal connection terminal, the CAN communication positive connection terminal, and the CAN communication negative connection terminal are respectively electrically connected to the detection control unit through a wire; the human-machine interaction unit and the charge and discharge unit are respectively electrically connected to the detection control unit through a bus.

[0009] Preferably, the detection control unit has a CAN communication function and can perform two-way CAN communication with the power battery to be detected through the CAN communication positive connection terminal and the CAN communication negative connection terminal; the wires between the detection unit and the detection connection plug are integrated in the connection wire harness and are isolated from each other through the insulating layers of the wires.

[0010] Preferably, the detection control unit can close or open the first status switch and / or the second status switch according to the instructions sent by the human-machine interaction unit or CAN communication, that is, the charge and discharge unit is made to switch states by sending instructions through the human-machine interaction unit or the CAN communication of the battery to be detected.

[0011] Preferably, when the charge and discharge unit is in the charging state / discharging state / charge and discharge state, the detection control unit can control the charge and discharge unit to perform a charging operation / discharging operation / charge and discharge operation on the power battery to be detected according to the working conditions set by the human-machine interaction unit or the working conditions set by CAN communication.

[0012] Preferably, the human-machine interaction unit is a host computer, a touch screen, or other devices that can realize information input and output.

[0013] Preferably, the bus is one of RS485, RS422, RS232, CAN, LIN, or any other means that can realize data communication.

[0014] Preferably, the resistance values of the first status resistor and the second status resistor are 0.1 - 10 kΩ; the first status switch and the second status switch are one of a solid-state relay, MOSFET, IGBT, triode, or any component that can realize circuit conduction and disconnection.

[0015] When the present invention is specifically applied, the shape of the detection connection plug can refer to the design of the charging gun corresponding to the DC charging socket of the vehicle to be detected, and the battery positive connection terminal, battery negative connection terminal, body ground connection terminal, detection status signal connection terminal, CAN communication positive connection terminal, and CAN communication negative connection terminal are respectively connected to the charging positive connection terminal, charging negative connection terminal, body ground connection terminal, charging confirmation signal connection terminal, CAN communication positive connection terminal, and CAN communication negative connection terminal of the DC charging socket in one-to-one correspondence. The other unused terminals can be left blank for convenient plugging.

[0016] Compared with the prior art, the detection device of the present invention can quickly detect the power battery loaded on the electric vehicle through the DC charging socket without disassembling the power battery and / or high-voltage wire harness. In particular, it can perform real-time identification of the detection status, simplifying the test process; through the CAN communication function, it can perform two-way communication and feedback the test results to the power battery, facilitating the measurement and correction of the operating parameters of the power battery by the electric vehicle; at the same time, the charge and discharge status is independently confirmed by means of resistance, avoiding damage to the battery caused by incorrect settings or operations, and increasing the safety and reliability of the system.

[0017] For the above reasons, the present invention can be widely promoted in the field of power battery detection for electric vehicles. Brief Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the charge and discharge detection device for the power battery of an electric vehicle according to the present invention.

[0019] Figure 2 is a schematic external structure diagram of Embodiment 1 of the charge and discharge detection device for the power battery of an electric vehicle according to the present invention.

[0020] Figure 3 is a schematic external structure diagram of Embodiment 2 of the charge and discharge detection device for the power battery of an electric vehicle according to the present invention.

[0021] In the figure, 1 is the detection connection plug, 2 is the detection unit, 3 is the connection wire harness, 4 is the human-computer interaction unit, 5 is the charge and discharge unit, 6 is the status control unit, 7 is the detection control unit, 8 is the detection equipment grounding terminal, 9 is the first status resistor, 10 is the first status switch, 11 is the second status resistor, and 12 is the second status switch. Detailed Embodiments

[0022] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Please refer to Figure 1 , Figure 1It is a schematic structural diagram of the charging and discharging detection device for the power battery of an electric vehicle according to the present invention. The charging and discharging detection device for the power battery of the electric vehicle shown includes a detection connection plug 1 and a detection unit 2; the detection connection plug 1 is connected to the detection unit 2 through a connection wire harness 3; the detection connection plug 1 is matched with the DC charging socket of the electric vehicle and at least includes a battery positive connection terminal DC+, a battery negative connection terminal DC-, a body ground connection terminal PE, a detection status signal connection terminal CC2, a CAN communication positive connection terminal S+, and a CAN communication negative connection terminal S-; the detection unit 2 includes a human-machine interaction unit 4, a detection control unit 7, a charging and discharging unit 5, and a status control unit 6. The status control unit 6 includes a detection device ground terminal 8, a first status resistor 9, a second status resistor 11, a first status switch 10, and a second status switch 12; one end of the first status resistor 9 is electrically connected to the detection device ground terminal 8, and the other end is electrically connected to the detection status signal connection terminal CC2 through the first status switch 10; one end of the second status resistor 11 is electrically connected to the detection device ground terminal 8, and the other end is electrically connected to the detection status signal connection terminal CC2 through the second status switch 12; the control ends of the first status switch 10 and the second status switch 12 are respectively electrically connected to the detection control unit 7. The battery positive connection terminal DC+ is electrically connected to the positive electrode DC+ of the charging and discharging unit 5 through a wire; the battery negative connection terminal DC- is electrically connected to the negative electrode DC- of the charging and discharging unit 5 through a wire; the body ground connection terminal PE is electrically connected to the detection device ground terminal 8 through a wire; the detection status signal connection terminal CC2, the CAN communication positive connection terminal S+, and the CAN communication negative connection terminal S- are respectively electrically connected to the detection control unit 7 through wires; the human-machine interaction unit 4 and the charging and discharging unit 5 are respectively electrically connected to the detection control unit 7 through a bus.

[0024] Embodiment 1.

[0025] Please refer to Figure 2 , Figure 2It is a schematic diagram of the external structure of Embodiment 1 of the charging and discharging detection device for the power battery of an electric vehicle according to the present invention. The charging and discharging detection device for the power battery of the electric vehicle in this embodiment includes a detection connection plug 1 and a detection unit 2; the detection connection plug 1 adopts an external shape design that matches the vehicle socket in GB / T 20234.3-2015 and is designed to be pluggable therewith; the connection terminals of the detection connection plug 1 include a battery positive connection terminal DC+, a battery negative connection terminal DC-, a body ground connection terminal PE, a detection status signal connection terminal CC2, a CAN communication positive connection terminal S+, and a CAN communication negative connection terminal S-, and respectively correspond to the charging positive connection terminal, the charging negative connection terminal, the body ground connection terminal, the charging confirmation signal connection terminal, the CAN communication positive connection terminal, and the CAN communication negative connection terminal of the DC charging socket, and the other unused terminals are left blank. The detection unit 2 includes a human-computer interaction unit 4, a detection control unit 7, a status control unit 6, and a charging and discharging unit 5; the human-computer interaction unit 4 is a touch screen and is electrically connected to the detection control unit 7 through an RS485 bus; the resistance value of the first status resistor 9 of the status control unit is 1 kΩ, the second status resistor 11 is 2 kΩ, the first status switch 10 and the second status switch 12 are both MOSFETs, and their control ends are electrically connected to the detection control unit 7; the charging and discharging unit 5 is electrically connected to the detection control unit 7 through an RS485 bus.

[0026] The charging and discharging unit 5 of the electric vehicle power battery charging and discharging detection device in this embodiment has four states: charging state, discharging state, charging and discharging state, and stop state. The resistance values between the detection device grounding terminal 8 and the detection state signal connection terminal CC2 corresponding to these states are 1 kΩ, 2 kΩ, 2 / 3 kΩ, and high impedance state (open circuit). The detection control unit 7 can control the charging and discharging unit 5 to be in the corresponding state according to its resistance value. At the same time, through the instructions of the touch screen 4, the detection control unit 7 can respectively set to only close the first state switch 10, only close the second state switch 12, close the first state switch 10 and the second state switch 12 simultaneously, and open the first state switch 10 and the second state switch 12 simultaneously to achieve the switching of four different states. The external battery to be detected monitors this resistance value through the detection state signal connection terminal CC2 during testing, thereby determining the current state of the detection device, and setting detection parameters according to the current state to avoid misoperation. For example, when the detection device is only used for discharging, the detection control unit 7 is instructed by the touch screen 4 to only close the second state switch 12. At this time, the resistance value between the detection device grounding terminal 8 and the detection state signal connection terminal CC2 is 2 kΩ, and the detection control unit 7 sets the charging and discharging unit 5 to enter the discharging state according to its resistance value; when the detection connection plug is inserted into the DC charging socket of the electric vehicle to detect the power battery, the power battery monitors that this resistance is 2 kΩ through the detection state signal connection terminal CC2. The current detection device only performs a discharging operation on the power battery. Therefore, only the discharging parameters are set through CAN communication and the results are returned, avoiding other incorrect settings or operations.

[0027] Using the electric vehicle power battery charging and discharging detection device of this example, the power battery loaded on the electric vehicle can be quickly detected through the DC charging socket without disassembling the power battery or / and the high-voltage harness. In particular, it can automatically identify the detection state, simplifying the test process.

[0028] Embodiment 2.

[0029] Please refer to Figure 3 , Figure 3It is a schematic diagram of the external structure of Embodiment 2 of the charging and discharging detection device for the power battery of an electric vehicle according to the present invention. The charging and discharging detection device for the power battery of an electric vehicle in this embodiment includes a detection connection plug 1 and a detection unit 2; the detection connection plug 1 adopts an external shape design that matches the vehicle socket in GB / T 20234.3-2015 and is designed to be pluggable therewith; the connection terminals of the detection connection plug 1 include a battery positive connection terminal DC+, a battery negative connection terminal DC-, a body ground connection terminal PE, a detection status signal connection terminal CC2, a CAN communication positive connection terminal S+, and a CAN communication negative connection terminal S-, and respectively correspond to the charging positive connection terminal, the charging negative connection terminal, the body ground connection terminal, the charging confirmation signal connection terminal, the CAN communication positive connection terminal, and the CAN communication negative connection terminal of the DC charging socket, and the other unused terminals are left blank. The detection unit 2 includes a human-computer interaction unit 4, a detection control unit 7, a status control unit 6, and a charging and discharging unit 5; the human-computer interaction unit 4 is a host computer and is electrically connected to the detection control unit 7 through a LIN bus; the resistance value of the first status resistor 9 of the status control unit 6 is 3 kΩ, the second status resistor 11 is 2 kΩ, the first status switch 10 and the second status switch 12 are both solid-state relays, and their control terminals are electrically connected to the detection control unit 7; the charging and discharging unit 5 is electrically connected to the detection control unit 7 through a LIN bus.

[0030] The charging and discharging unit 5 of the electric vehicle power battery charging and discharging detection device in this embodiment has five states: charging state, discharging state, charging and discharging state, stop state, and fault state. The resistance values between the detection equipment grounding terminal 8 and the detection state signal connection terminal CC2 corresponding to them are 3 kΩ, 2 kΩ, 1.2 kΩ, high impedance state (open circuit), 2 kΩ, and 1.2 kΩ with a 10 Hz periodic change. The detection control unit 7 can control the charging and discharging unit 5 to be in the corresponding state according to its resistance value. At the same time, through the instruction of the host computer or the CAN instruction of the power battery to be detected, the detection control unit 7 can respectively set to only close the first state switch 10, only close the second state switch 12, close the first state switch 10 and the second state switch 12 at the same time, disconnect the first state switch 10 and the second state switch 12 at the same time, keep the second state switch 12 normally closed and close and disconnect the first state switch 10 at 10 Hz to realize the switching of five different states. The power battery to be detected monitors this resistance value through the detection state signal connection terminal CC2 during the test, and then determines the state of the current detection device, and sets the detection parameters according to the current state to avoid misoperation. At the same time, different states can be set to be switched through the CAN instruction as needed during the detection process. For example, when the detection equipment is only used for charging, the detection control unit 7 is instructed by the host computer 4 to only close the first state switch 10. At this time, the resistance value between the detection equipment grounding terminal 8 and the detection state signal connection terminal CC2 is 3 kΩ, and the detection control unit 7 sets the charging and discharging unit 5 to enter the charging state according to its resistance value; when the detection connection plug is inserted into the DC socket of the electric vehicle to detect the power battery, the power battery monitors that this resistance is 3 kΩ through the detection state signal connection terminal CC2. The current detection device only performs a charging operation on the battery. Therefore, only the charging parameters are set through CAN communication and the test results are returned after the test, avoiding other incorrect settings or operations. During the charging process, if a fault occurs in the power battery to be detected, the second state switch 12 can be set to be normally closed and the first state switch 10 can be closed and disconnected at 10 Hz through the CAN communication instruction to set the charging and discharging unit to the fault state. At the same time, it can be monitored through the detection state signal connection terminal CC2 whether this resistance state is correctly set to confirm whether the corresponding instruction is normally executed, so that the unprocessed instruction can be quickly resent or processed, avoiding damage to the power battery or the detection device caused by this, and strengthening the reliability of the system.

[0031] The electric vehicle power battery charge and discharge detection device of this embodiment can not only quickly detect the power battery loaded on the electric vehicle through the DC charging socket without disassembling the power battery or / and the high-voltage wire harness, and return the results through bidirectional interaction of CAN communication, which is convenient for the electric vehicle to correct the operation parameters of the power battery, but also can automatically identify and switch the detection state, thus realizing automatic detection; at the same time, the charge and discharge states are independently confirmed by means of resistance, avoiding damage to the power battery caused by incorrect settings or operations, and increasing the safety and reliability of the system.

[0032] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. An electric vehicle power battery charge and discharge detection device, characterized in that: The device includes a detection connection plug and a detection unit; the detection connection plug is connected to the detection unit through a connection harness; the detection connection plug is matched with the DC charging socket of the electric vehicle and at least includes a battery positive connection terminal, a battery negative connection terminal, a body ground connection terminal, a detection status signal connection terminal, a CAN communication positive connection terminal, and a CAN communication negative connection terminal; the detection unit includes a human-machine interaction unit, a detection control unit, a status control unit, and a charge and discharge unit; The status control unit includes a detection device ground terminal, a first status resistor, a second status resistor, a first status switch, and a second status switch; one end of the first status resistor is electrically connected to the detection device ground terminal, and the other end is electrically connected to the detection status signal connection terminal through the first status switch; one end of the second status resistor is electrically connected to the detection device ground terminal, and the other end is electrically connected to the detection status signal connection terminal through the second status switch; the control ends of the first status switch and the second status switch are respectively electrically connected to the detection control unit; The detection control unit can control the charge and discharge unit to be in a charging state, a discharging state, or a charge and discharge state according to the resistance value or / and the periodic change frequency value of the resistance between the detection device ground terminal and the detection status signal connection terminal; the power battery to be detected obtains the resistance value or / and the periodic change frequency value of the resistance through the detection status signal connection terminal to determine the state of the charge and discharge unit, and sets corresponding power battery parameters according to the state; The detection control unit has a CAN communication function and can perform two-way CAN communication with the power battery to be detected through the CAN communication positive connection terminal and the CAN communication negative connection terminal; the wires between the detection unit and the detection connection plug are integrated in the connection harness and are isolated from each other through the insulating layers of the wires; The detection control unit can close or open the first status switch or / and the second status switch according to the instructions sent by the human-machine interaction unit or CAN communication.

2. The charging and discharging detection device for the power battery of an electric vehicle according to claim 1, wherein: The battery positive connection terminal is electrically connected to the positive electrode of the charge and discharge unit through a wire; the battery negative connection terminal is electrically connected to the negative electrode of the charge and discharge unit through a wire; the body ground connection terminal is electrically connected to the detection device ground terminal through a wire; the detection status signal connection terminal, the CAN communication positive connection terminal, and the CAN communication negative connection terminal are respectively electrically connected to the detection control unit through wires; the human-machine interaction unit and the charge and discharge unit are respectively electrically connected to the detection control unit through a bus.

3. The charging and discharging detection device for the power battery of an electric vehicle according to claim 1, wherein: When the charge and discharge unit is in a charging state / discharging state / charge and discharge state, the detection control unit can control the charge and discharge unit to perform a charging operation / discharging operation / charge and discharge operation on the power battery to be detected according to the working conditions set by the human-machine interaction unit or the working conditions set by CAN communication.

4. A charging and discharging detection device for an electric vehicle power battery according to claim 1, characterized in that: The human-machine interaction unit is a host computer or a touch screen.

5. The charging and discharging detection device for the power battery of an electric vehicle according to claim 2, characterized in that: The bus is RS485, RS422, RS232, CAN, or LIN.

6. The charging and discharging detection device for the power battery of an electric vehicle according to claim 1, wherein: The resistance values of the first-state resistor and the second-state resistor are 0.1 - 10 kΩ; the first-state switch and the second-state switch are solid-state relays, MOSFETs, IGBTs or triodes.

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