An online detection device and online detection method for electric vehicle power battery pack

Abstract

The present application discloses an online detection device and an online detection method for an electric vehicle power battery pack, and relates to the technical field of battery pack detection. The online detection device includes: a box, one end of which is provided with a charging seat, and the other end is connected to a charging gun, and the charging gun is used to connect the electric vehicle power battery pack; a current transmitter, which is used to collect the charging current of the power battery pack in real time; a controller, which is used to obtain the remaining power SOC value of the power battery pack in real time, and is also used to calculate the actual charging capacity and battery health status value of the power battery pack according to the real-time charging current; a switching power supply, whose input end is connected to the power output end of the charging seat, and the output end of the switching power supply is connected to the current transmitter and the controller, which is used to charge the current transmitter and the controller. The present application can judge the health status of the power battery pack according to the calculated battery health status value, which not only avoids the disassembly of the battery pack, but also greatly shortens the detection time and improves the detection efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of battery pack detection, and in particular to an online detection device and an online detection method for an electric vehicle power battery pack. Background Art

[0002] At present, the inspection of new energy vehicles and power batteries only occurs in the mandatory inspection before the new energy vehicles leave the factory. There is little tracking, inspection and maintenance during the use of power batteries, which results in the inability of car owners, 4S stores and car companies to grasp the real-time status of power batteries. They can only passively repair them after the power batteries fail. This not only greatly reduces the service life of power batteries, but also leads to frequent safety accidents of new energy vehicles. In addition, due to the decline in the health of power batteries, the actual mileage of new energy vehicles is often lower than the displayed mileage, and it is common for them to break down halfway. The main reason for the above problems is that during the use of the power battery pack, the current acquisition system and voltage acquisition system inside it will change with time / temperature, resulting in a decrease in acquisition accuracy or even failure. It is difficult for users and maintenance personnel of the power battery pack to judge whether its capacity meets the standard under the existing conditions, or whether the manufacturer has false standards.

[0003] In the related art, the power battery pack is generally sent to a third-party laboratory for overall charge and discharge testing to determine whether the capacity of the battery pack and the data collection of the BMS system meet the standards.

[0004] However, the charge and discharge test is not only time-consuming, but also has high requirements for the quality of experimental equipment and testing personnel, and is expensive. In addition, the disassembly and assembly of the power battery pack is very complicated, requiring professional engineers to spend a lot of time and effort to carry out, which is time-consuming and laborious. Summary of the invention

[0005] In view of one of the defects existing in the prior art, the purpose of the present application is to provide an online detection device and an online detection method for an electric vehicle power battery pack to solve the problem that the existing charging and discharging tests are time-consuming and labor-intensive.

[0006] The first aspect of the present application provides an online detection device for an electric vehicle power battery pack, which comprises:

[0007] A box body, one end of which is provided with a charging seat for connecting to a charging pile, and the other end is connected to a charging gun, and the charging gun is used to connect to the power battery pack of an electric vehicle;

[0008] A current transmitter is provided in the box, which is electrically connected to the charging base and the charging gun, and is used to collect the charging current of the power battery pack in real time;

[0009] The controller is arranged in the box, which is electrically connected to the charging base and the charging gun, and is used to obtain the remaining power SOC value of the power battery pack in real time, and is also used to calculate the actual charging capacity and battery health status value of the power battery pack according to the charging current collected in real time;

[0010] A switching power supply, whose input end is connected to the power output end of the above-mentioned charging base, and the output end of the above-mentioned switching power supply is connected to the above-mentioned current transmitter and controller, and is used to charge the above-mentioned current transmitter and controller.

[0011] In some embodiments, it also includes: a voltage transmitter, which is electrically connected to the charging base and the charging gun, and is used to collect the charging voltage of the power battery pack in real time and send it to the controller.

[0012] In some embodiments, the controller is further configured to stop calculation when the charging voltage exceeds a preset voltage range.

[0013] In some embodiments, the switching power supply includes a power change module and a power switch connected to each other, the power switch is connected to the power output terminal of the charging base, and the power change module is used to convert the input AC power into DC power.

[0014] The second aspect of the present application provides an online detection method based on the above-mentioned online detection device for electric vehicle power battery pack, which comprises the steps of:

[0015] Obtaining an SOC value of the power battery pack during initial charging as a first SOC, and setting an SOC difference;

[0016] When the first SOC is within the preset range, the power battery pack is charged by the charging gun, and when the first SOC is increased by 1, the charging ampere-hours are accumulated, and the SOC value after the increase of 1 is used as the initial SOC, and the sum of the difference between the initial SOC and the SOC is used as the final SOC;

[0017] When the SOC value of the power battery pack reaches the termination SOC, the charging ampere-hour of the power battery pack from the initial SOC to the termination SOC is obtained, and the first actual charging capacity and the battery health status value of the power battery pack are calculated.

[0018] In some embodiments, when the first SOC is less than or equal to the minimum value of the preset range, the power battery pack is charged until the first SOC is greater than the minimum value.

[0019] In some embodiments, obtaining the charging ampere-hour of the power battery pack from the initial SOC to the final SOC, and calculating the first actual charging capacity and the battery health status value of the power battery pack specifically include:

[0020] Obtaining the charging current and charging time of the power battery pack from the initial SOC to the final SOC, and integrating the charging current to obtain the charging ampere-hour from the initial SOC to the final SOC;

[0021] The ratio of the charging ampere-hour to the SOC difference is used as the first actual charging capacity;

[0022] The ratio of the first actual charging capacity to the rated capacity is used as the battery health status value.

[0023] In some embodiments, when charging the power battery pack through the charging gun, the method further includes:

[0024] The charging voltage output by the switching power supply is collected in real time through a voltage transmitter;

[0025] When the charging voltage exceeds the preset voltage range, the calculation stops.

[0026] In some embodiments, before the SOC value of the power battery pack reaches the termination SOC, the process further includes:

[0027] Selecting multiple SOC values ​​between the initial SOC and the final SOC;

[0028] Respectively obtain the charging ampere-hours from the initial SOC to each SOC value to obtain multiple actual charging capacities;

[0029] Performing weighted summation according to weights corresponding to the actual charging capacities including the first actual charging capacity;

[0030] The battery health status value is calculated based on the weighted sum of the actual charging capacity and the rated capacity of the battery pack.

[0031] In some embodiments, before the SOC value of the power battery pack reaches the termination SOC, the process further includes:

[0032] The second SOC value is taken as the end SOC minus 2, and the third SOC value is taken as the end SOC minus 1, and the second SOC value and the third SOC value are selected;

[0033] When the SOC value of the power battery pack reaches a second SOC value, obtaining a second actual charging capacity of the power battery pack from the initial SOC to the second SOC value;

[0034] When the SOC value of the power battery pack reaches a third SOC value, obtaining a third actual charging capacity of the power battery pack from the initial SOC to the third SOC value;

[0035] Performing a weighted sum according to weights corresponding to the first actual charging capacity, the second actual charging capacity, and the third actual charging capacity;

[0036] The battery health status value is calculated based on the weighted sum of the actual charging capacity and the rated capacity of the battery pack.

[0037] The beneficial effects of the technical solution provided by this application include:

[0038] The electric vehicle power battery pack online detection equipment and online detection method of the present application has a charging seat for connecting to a charging pile on one side of the box body, and a charging gun connected to the electric vehicle power battery pack on the other side. During the charging process of the power battery pack, the controller can obtain the SOC value of the power battery pack in real time, and calculate the actual charging capacity and battery health status value of the power battery pack based on the charging current collected in real time. Therefore, the health status of the power battery pack can be judged based on the calculated battery health status value, which not only avoids the disassembly of the battery pack, but also greatly shortens the detection time and improves the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of an online detection device for an electric vehicle power battery pack provided in an embodiment of the present application;

[0040] Figure 2 A flow chart of an online detection method for an electric vehicle power battery pack provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0042] See also Figure 1 As shown, an embodiment of the present application provides an online detection device for an electric vehicle power battery pack, which includes a box body, a switching power supply, a current transmitter and a controller.

[0043] A charging seat for connecting to a charging pile is provided on one side of the box, and a charging gun is connected to the other side of the box. The charging gun is used to connect to the charging port of an electric car to charge the power battery pack.

[0044] The current transmitter is arranged in the above-mentioned box body, and the current transmitter is electrically connected to the above-mentioned charging seat and the charging gun. The current transmitter is used to collect the charging current of the above-mentioned power battery pack in real time and send it to the controller.

[0045] The controller is arranged in the above-mentioned box body, and is electrically connected to the above-mentioned charging seat and charging gun. The controller is used to obtain the SOC (State of Charge, remaining power) value of the above-mentioned power battery pack in real time. The controller is also electrically connected to the current transmitter, and calculates the actual charging capacity and battery health status value of the above-mentioned power battery pack according to the real-time collected charging current sent by the current transmitter. According to the calculated battery health status value, the health status of the power battery pack can be determined.

[0046] The input end of the switching power supply is connected to the power output end of the above-mentioned charging base, and the output end of the above-mentioned switching power supply is connected to the above-mentioned current transmitter and controller. The switching power supply can convert the input 220V AC power into direct current to power the above-mentioned current transmitter and controller.

[0047] The online detection device of the embodiment of the present application is small in size and easy to move. Since a charging seat for connecting to a charging pile is provided on one side of the box, and a charging gun connected to the electric vehicle power battery pack is connected on the other side, during the charging process of the power battery pack, the controller can obtain the SOC value of the power battery pack in real time, and calculate the actual charging capacity and battery health status value of the power battery pack based on the real-time collected charging current. Therefore, the health status of the power battery pack can be judged based on the calculated battery health status value, which not only avoids the disassembly of the battery pack, but also greatly shortens the detection time and improves the detection efficiency

[0048] The online detection device of this embodiment further includes a voltage transmitter, which is electrically connected to the charging base and the charging gun, and is used to collect the charging voltage of the power battery pack in real time and send it to the controller. When the charging voltage exceeds a preset voltage range, the controller is also used to stop the calculation, thereby ending the detection process.

[0049] The switching power supply comprises a power change module and a power switch which are connected to each other. The power switch is connected to the power output terminal of the charging base. The power change module is used to convert the input alternating current into direct current.

[0050] In this embodiment, the power change module is arranged in the above-mentioned box body, the above-mentioned power switch is arranged on the above-mentioned side wall of the box body, the power switch and the charging seat are arranged on the same side wall of the box body, and the charging gun is arranged on the other side wall opposite to the box body.

[0051] Furthermore, the charging base includes a first connection terminal group, the charging gun includes a second connection terminal group, and the first connection terminal group is electrically connected to the second connection terminal group. The charging base is connected to the charging gun head of the charging pile, and then the charging gun is inserted into the electric vehicle to be tested. After closing the power switch, the charging pile can be started, and the handshake between the charging pile and the electric vehicle to be tested is successfully waited.

[0052] Specifically, the above-mentioned first connection terminal group includes a first DC power supply DC+, a first DC-, a first auxiliary power supply A+, a first A-, a first CAN communication pin S+, a first S-, a first connection confirmation detection point CC1, a first CC2 and a first ground pin 0, a total of 9 connection terminals.

[0053] The second connection terminal group includes a second DC+, a second DC-, a second A+, a second A-, a second S+, a second S-, a second CC1, a second CC2 and a second ground pin 0 which are connected to the first connection terminal group in a one-to-one correspondence, for a total of 9 connection terminals.

[0054] Among them, the first ground pin 0 and the second ground pin 0 are protective grounding; the first DC+ and the second DC+ are connected, and the first DC- and the second DC- are connected, indicating that a DC power supply is provided for the charging gun; the first A+ and the second A+ are connected, and the first A- and the second A- are connected, indicating that a low-voltage auxiliary power supply is provided for the charging gun; the first S+ and the second S+ are connected, and the first S- and the second S- are connected, indicating that the CAN communication interface is connected, the first CC1 and the second CC1 are connected, and the first CC2 and the second CC2 are connected, indicating that the charging connection is confirmed.

[0055] In this embodiment, a touch screen is also provided on the surface of the box, and the output end of the controller is connected to the touch screen. Optionally, a printer is also provided on the box, and the output end of the controller is also connected to the printer.

[0056] In this embodiment, the switching power supply is a power supply that converts 220V to 24V, 12V and 5V. The charging station connects the 220V AC mains to the power switch interface, and then outputs +24V DC, +12V DC and +5V DC after passing through the power conversion module, where +12V DC powers the voltage transducer and the current transducer, +5V DC powers the controller, and +24V DC powers the touch screen 8 and the printer 9.

[0057] Specifically, after the detection is started by controlling the start button on the touch screen, the voltage transmitter collects the online charging voltage and converts it into a 0-5V DC voltage signal and outputs it to the controller. The current transmitter collects the charging current and converts it into a 0-5V DC voltage signal and outputs it to the controller. The SOC information of the electric vehicle is connected to the controller via the CAN communication bus. After the controller performs calculations, the above calculation results can be uploaded to the touch screen 8 via RS485 communication, and the calculation results can be generated into a detection report, which can be transmitted to the printer 9 via RS485 and print the required report. Optionally, the controller is a DSP (Digital Signal Processing) controller.

[0058] In this embodiment, the charging seat is directly connected to the charging pile, and the charging gun on one side of the box can be directly and seamlessly connected to the electric vehicle charging port, avoiding the disassembly of the battery pack, and plug and play. All interfaces are hard-connected, and no additional cables are required. Optionally, the power battery pack is a lithium battery pack.

[0059] See also Figure 2 As shown, the embodiment of the present application also provides an online detection method based on the above-mentioned electric vehicle power battery pack online detection device, which includes the steps of:

[0060] S1. Obtain the SOC value of the power battery pack during initial charging as a first SOC, and set the SOC difference.

[0061] S2. When the above-mentioned first SOC is within the preset range, the power battery pack is charged through the charging gun, and when the above-mentioned first SOC is increased by 1, the charging ampere-hours are accumulated, and the SOC value after the increase of 1 is used as the initial SOC, and the sum of the difference between the above-mentioned initial SOC and the SOC is used as the termination SOC, that is, the termination condition is determined.

[0062] S3. When the SOC value of the power battery pack reaches the termination SOC, the charging ampere-hour of the power battery pack from the initial SOC to the termination SOC is obtained, and the first actual charging capacity and the battery health status value of the power battery pack are calculated to determine the health status of the power battery pack.

[0063] Preferably, when the above-mentioned first SOC is less than or equal to the minimum value of the above-mentioned preset range, the power battery pack is charged by a charging gun until the above-mentioned first SOC is greater than the above-mentioned minimum value, and then the power battery pack can continue to be charged to the first SOC plus 1 for testing.

[0064] In other embodiments, when the first SOC is greater than or equal to the maximum value of the preset range, the power battery pack may be discharged by a discharge device until the first SOC is less than the maximum value, and then detection may be performed.

[0065] In this embodiment, the minimum value of the preset range is 24%, and the maximum value of the preset range is the difference between 74% and the SOC difference, that is, the initial SOC must be greater than 25%, and the final SOC must be less than 75%, so as to prevent the measurement deviation that may occur in the initial and final stages of charging of the battery pack.

[0066] Furthermore, in the above step S3, the charging ampere-hour of the above power battery pack from the initial SOC to the final SOC is obtained, and the first actual charging capacity and the battery health status value of the above power battery pack are calculated, which specifically includes:

[0067] First, the charging current and charging time of the power battery pack from the initial SOC to the final SOC are obtained, and the charging current is integrated to obtain the charging ampere-hour from the initial SOC to the final SOC.

[0068] Then, the ratio of the above charging ampere-hours to the set SOC difference is used as the first actual charging capacity. That is, the first actual charging capacity Q1 is:

[0069]

[0070] Among them, I is the charging current, t is the charging time, SOC0 is the initial SOC, SOC t To terminate SOC.

[0071] Finally, the ratio of the first actual charging capacity Q1 to the rated capacity Q0 is used as the battery health state value η1:

[0072]

[0073] Preferably, when charging the power battery pack through the charging gun, the method further includes:

[0074] The charging voltage output by the switching power supply is collected in real time through the voltage transmitter. When the charging voltage exceeds the preset voltage range, it indicates that the charging detection process is abnormal and the detection needs to be stopped.

[0075] Furthermore, before the SOC value of the power battery pack reaches the termination SOC, the step S3 further includes:

[0076] First, multiple SOC values ​​between the initial SOC and the final SOC are selected.

[0077] Then, the charging ampere-hours from the initial SOC to each SOC value are obtained respectively to obtain a plurality of actual charging capacities.

[0078] After the first actual charging capacity is calculated, a weighted sum is performed according to the weights corresponding to the actual charging capacities including the first actual charging capacity, and the battery health status value is calculated according to the actual charging capacity after the weighted sum and the rated capacity of the battery pack. The weights of this embodiment can be calibrated by using an actual vehicle test of the same type of power battery pack.

[0079] In this embodiment, before the SOC value of the power battery pack reaches the termination SOC, the process further includes:

[0080] First, a second SOC value and a third SOC value between the initial SOC and the final SOC are selected, wherein the final SOC minus 2 is the second SOC value, and the final SOC minus 1 is the third SOC value.

[0081] Secondly, when the SOC value of the power battery pack reaches a second SOC value, a second actual charging capacity Q2 of the power battery pack from the initial SOC to the second SOC value is obtained.

[0082] Then, when the SOC value of the power battery pack reaches a third SOC value, a third actual charging capacity Q3 of the power battery pack from the initial SOC to the third SOC value is obtained.

[0083] Finally, a weighted sum is performed according to the weights corresponding to the first actual charging capacity Q1, the second actual charging capacity Q2 and the third actual charging capacity Q3, and the battery health status value of the above-mentioned power battery pack is calculated according to the actual charging capacity Q after the weighted sum and the rated capacity Q0 of the above-mentioned battery pack, that is, the ratio of the above-mentioned actual charging capacity to the rated capacity is used as the battery health status value.

[0084] In this embodiment, the weight of the first actual charging capacity Q1 is 1-xy, the weight corresponding to the second actual charging capacity Q2 is x, and the weight corresponding to the third actual charging capacity Q3 is y. The actual charging capacity Q after weighted summation is:

[0085] Q=(1-xy)Q1+xQ2+yQ3

[0086] Preferably, x=0.1-0.4, y=0.1-0.3.

[0087] The online detection method of this embodiment is applicable to the above-mentioned online detection devices. It not only simplifies the detection process, but also avoids the error of single value acquisition caused by factors such as battery impedance, thereby improving the accuracy of the test results.

[0088] The present application is not limited to the above-mentioned implementation modes. For ordinary technicians in the technical field, several improvements and modifications can be made without departing from the principles of the present application, and these improvements and modifications are also considered to be within the scope of protection of the present application. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field.

Claims

1. An online testing device for electric vehicle power battery pack, characterized in that: It includes: A box body, one end of which is provided with a charging seat for connecting to a charging pile, and the other end is connected to a charging gun, and the charging gun is used to connect to the power battery pack of the electric vehicle; A current transmitter is arranged in the box, which is electrically connected to the charging seat and the charging gun, and is used to collect the charging current of the power battery pack in real time; A controller is disposed in the box, which is electrically connected to the charging base and the charging gun, and is used to obtain the remaining power SOC value of the power battery pack in real time, and is also used to calculate the actual charging capacity and battery health status value of the power battery pack according to the charging current collected in real time; A switching power supply, whose input end is connected to the power output end of the charging base, and whose output end is connected to the current transmitter and the controller, for charging the current transmitter and the controller; It also includes: a voltage transmitter, which is electrically connected to the charging base and the charging gun, and is used to collect the charging voltage of the power battery pack in real time and send it to the controller; The switching power supply includes a power change module and a power switch which are connected to each other. The power switch is connected to the power output terminal of the charging base. The power change module is used to convert the input alternating current into direct current.

2. The electric vehicle power battery pack online detection equipment according to claim 1, characterized in that: The controller is also used to stop calculating when the charging voltage exceeds a preset voltage range.

3. An online detection method based on the online detection device for electric vehicle power battery pack according to claim 1, characterized in that: It includes the steps of: Obtaining an SOC value of the power battery pack during initial charging as a first SOC, and setting an SOC difference; When the first SOC is within a preset range, the power battery pack is charged through a charging gun, and when the first SOC is increased by 1, the charging ampere-hours are accumulated, and the SOC value after the increase by 1 is used as the initial SOC, and the sum of the initial SOC and the SOC difference is used as the final SOC; When the SOC value of the power battery pack reaches the termination SOC, the charging ampere-hour of the power battery pack from the initial SOC to the termination SOC is obtained, and a first actual charging capacity and a battery health status value of the power battery pack are calculated.

4. The online detection method according to claim 3, characterized in that: When the first SOC is less than or equal to a minimum value of the preset range, the power battery pack is charged until the first SOC is greater than the minimum value.

5. The online detection method according to claim 3, characterized in that: The obtaining of the charging ampere-hour of the power battery pack from the initial SOC to the final SOC, and calculating the first actual charging capacity and the battery health status value of the power battery pack, specifically includes: Obtaining a charging current and a charging time of the power battery pack from the initial SOC to the final SOC, and integrating the charging current to obtain a charging ampere-hour from the initial SOC to the final SOC; Taking the ratio of the charging ampere-hour to the SOC difference as the first actual charging capacity; The ratio of the first actual charging capacity to the rated capacity is used as the battery health state value.

6. The online detection method according to claim 3, characterized in that: When the power battery pack is charged by the charging gun, it also includes: The charging voltage output by the switching power supply is collected in real time through a voltage transmitter; When the charging voltage exceeds a preset voltage range, the calculation is stopped.

7. The online detection method according to claim 3, characterized in that: Before the SOC value of the power battery pack reaches the termination SOC, the method further includes: Selecting a plurality of SOC values ​​between the initial SOC and the final SOC; Respectively acquiring charging ampere-hours from the initial SOC to each SOC value to obtain a plurality of actual charging capacities; Performing weighted summation according to weights corresponding to the actual charging capacities including the first actual charging capacity; The battery health status value is calculated based on the weighted sum of the actual charging capacity and the rated capacity of the battery pack.

8. The online detection method according to claim 7, characterized in that: Before the SOC value of the power battery pack reaches the termination SOC, the method further includes: The second SOC value is taken as the end SOC minus 2, and the third SOC value is taken as the end SOC minus 1, and the second SOC value and the third SOC value are selected; When the SOC value of the power battery pack reaches a second SOC value, obtaining a second actual charging capacity of the power battery pack from the initial SOC to the second SOC value; When the SOC value of the power battery pack reaches a third SOC value, obtaining a third actual charging capacity of the power battery pack from the initial SOC to the third SOC value; Performing a weighted sum according to weights corresponding to the first actual charging capacity, the second actual charging capacity, and the third actual charging capacity; The battery health status value is calculated based on the weighted sum of the actual charging capacity and the rated capacity of the battery pack.

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