High-voltage connection detection circuit of electric automobile, power supply system and electric automobile

Abstract

The utility model provides a high-voltage connection detection circuit of an electric vehicle, a power supply system and the electric vehicle, and relates to the technical field of vehicles. The high-voltage connection detection circuit comprises a control module, an acquisition module and a processing module, and the input ends of a plurality of first acquisition units in the acquisition module are used for being connected with first high-voltage connection points of a plurality of high-voltage branches in a power supply system of the electric vehicle. The input ends of the plurality of second acquisition units are respectively used for connecting second high-voltage connection points of a plurality of high-voltage branches in the power supply system; the output ends of the first acquisition units and the output ends of the second acquisition units are connected with the processing module, the processing module is connected with the control module, and the control module is further connected with the control ends of the relays connected with the first high-voltage connection points of the high-voltage branches. Whether the high-voltage connection points work normally or not can be determined by detecting the contact resistance of the high-voltage connection points of the plurality of high-voltage branches, so that the use safety of the electric vehicle is ensured.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a high-voltage connection detection circuit, a power supply system, and an electric vehicle. Background Technology

[0002] With the development of new energy technologies, electric vehicles are becoming increasingly popular, and the safety of electric vehicle use is receiving more and more attention.

[0003] Electric vehicle power supply systems typically include multiple high-voltage branches. Whether the connection points of these high-voltage branches can work reliably is directly related to the safety of electric vehicle use. Therefore, how to conduct safety testing on high-voltage connection points is an urgent problem to be solved. Utility Model Content

[0004] This application addresses the shortcomings of the prior art by providing a high-voltage connection detection circuit, a power supply system, and an electric vehicle, in order to solve the problems existing in the prior art.

[0005] The technical solution adopted in the embodiments of this application is as follows:

[0006] In a first aspect, embodiments of this application provide a high-voltage connection detection circuit for an electric vehicle, comprising: a control module, a data acquisition module, and a processing module, wherein the data acquisition module comprises: a plurality of first data acquisition units and a plurality of second data acquisition units;

[0007] The input terminals of the plurality of first acquisition units are respectively used to connect to the first high-voltage connection points of the plurality of high-voltage branches in the power supply system of the electric vehicle, and the input terminals of the plurality of second acquisition units are respectively used to connect to the second high-voltage connection points of the plurality of high-voltage branches in the power supply system.

[0008] The output terminals of the plurality of first acquisition units and the output terminals of the plurality of second acquisition units are all connected to the processing module. The processing module is connected to the control module. The control module is also connected to the control terminals of the plurality of relays connected to the first high-voltage connection points of the plurality of high-voltage branches.

[0009] In one embodiment, each first acquisition unit includes: a plurality of first resistors, the input terminal of each first acquisition unit is the first end of the plurality of first resistors, all connected to the first high-voltage connection point of the same high-voltage branch, and the output terminal of each first acquisition unit includes: the second end of the plurality of first resistors, respectively connected to the processing module;

[0010] Each second acquisition unit includes: multiple second resistors, the input terminal of each second acquisition unit is the first terminal of the multiple second resistors, all connected to the second high-voltage connection point of the same high-voltage branch, and the output terminal of each second acquisition unit includes: the second terminal of the multiple second resistors, which are respectively connected to the processing module.

[0011] In one embodiment, the high-voltage connection detection circuit further includes: a plurality of voltage divider resistors;

[0012] The control module is connected to the control terminals of the multiple relays through the multiple voltage divider resistors.

[0013] In one embodiment, the high-voltage connection detection circuit further includes a communication module, the processing module being connected to the communication module, and the communication module being used to connect to the vehicle controller of the electric vehicle.

[0014] Secondly, this application provides a power supply system for an electric vehicle, including: a power battery, multiple high-voltage branches, a battery management system, and the high-voltage connection detection circuit described in the above embodiments; the power battery is connected to a first high-voltage connection point of the multiple high-voltage branches, the second high-voltage connection points of the multiple high-voltage branches are respectively used to connect to multiple high-voltage devices, and the power battery is also connected to the battery management system;

[0015] In the high-voltage connection detection circuit, the input terminals of multiple first acquisition units are respectively connected to the first high-voltage connection points of the multiple high-voltage branches, the input terminals of multiple second acquisition units are respectively connected to the second high-voltage connection points of the multiple high-voltage branches, and the control module in the high-voltage connection detection circuit is also connected to the control terminals of multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

[0016] In one embodiment, the plurality of relays are also connected in parallel with a plurality of temperature control switches.

[0017] In one embodiment, the power battery is connected to the first high-voltage connection point of the plurality of high-voltage branches through a plurality of thermistors, and the plurality of thermistors are connected to the battery management system.

[0018] In one embodiment, the power battery is connected to the first high-voltage connection point of the plurality of high-voltage branches through a plurality of first amplification circuits, and the second high-voltage connection point of the plurality of high-voltage branches is connected to the plurality of high-voltage devices through a plurality of second amplification circuits.

[0019] In one embodiment, the plurality of high-voltage branches include: a high-voltage main positive branch, a high-voltage charging branch, a high-voltage auxiliary drive branch, and a high-voltage main negative branch;

[0020] The first high-voltage connection point of the high-voltage main positive branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the positive terminal of at least one high-voltage load.

[0021] The first high-voltage connection point of the high-voltage charging branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage charging branch is connected to the positive terminal of the high-voltage charging equipment.

[0022] The first high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive terminal of the high-voltage auxiliary drive equipment.

[0023] The first high-voltage connection point of the high-voltage main negative branch is connected to the negative terminal of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the negative terminal of all high-voltage equipment.

[0024] Thirdly, embodiments of this application provide an electric vehicle, which includes at least a vehicle body and a power supply system for the electric vehicle described in the above embodiments.

[0025] The beneficial effects of this application are as follows: This application provides a high-voltage connection detection circuit for an electric vehicle, including a control module, a data acquisition module, and a processing module. The data acquisition module includes multiple first data acquisition units and multiple second data acquisition units. The input terminals of the multiple first data acquisition units are respectively used to connect to the first high-voltage connection points of multiple high-voltage branches in the power supply system of the electric vehicle. The input terminals of the multiple second data acquisition units are respectively used to connect to the second high-voltage connection points of multiple high-voltage branches in the power supply system. The output terminals of the multiple first data acquisition units and the multiple second data acquisition units are all connected to the processing module. The processing module is connected to the control module. The control module is also connected to the control terminals of multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

[0026] The high-voltage connection detection circuit for electric vehicles provided in this application can detect the contact resistance of high-voltage connection points of multiple high-voltage branches through a data acquisition module and a processing module, thereby determining whether the high-voltage connection points are working properly and ensuring the safe use of electric vehicles. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 One of the structural schematic diagrams of a high-voltage connection detection circuit for an electric vehicle provided in an embodiment of this application;

[0029] Figure 2 A second schematic diagram of the high-voltage connection detection circuit for an electric vehicle provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of the first acquisition unit provided in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the structure of the second acquisition unit provided in an embodiment of this application;

[0032] Figure 5 The third schematic diagram of the high-voltage connection detection circuit for an electric vehicle provided in this application embodiment;

[0033] Figure 6 One of the structural schematic diagrams of the power supply system for the electric vehicle provided in this application;

[0034] Figure 7 A second schematic diagram of the power supply system for the electric vehicle provided in this application;

[0035] Figure 8 This is a schematic diagram of the high-voltage branch structure provided in this application;

[0036] Figure 9 The third schematic diagram of the power supply system for the electric vehicle provided in this application;

[0037] Figure 10 A schematic diagram of the amplifier circuit provided in this application.

[0038] Explanation of reference numerals in the attached diagram: 1. Control module; 2. Acquisition module; 3. Processing module; 4. Communication module. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0040] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0042] Furthermore, the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Additionally, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can be a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0045] Electric vehicle power supply systems typically include multiple high-voltage branches, such as discharge circuits, charging circuits, and auxiliary drive circuits. After an electric vehicle has been running for a long time, the high-voltage connection points in these high-voltage branches may become loose, leading to increased contact resistance and increasing the risk of fire. Therefore, whether the high-voltage connection points in the high-voltage branches can work reliably is directly related to the safety of the electric vehicle itself and its users.

[0046] To address the aforementioned problems, this application provides a high-voltage connection detection circuit for electric vehicles. The following, in conjunction with the accompanying drawings, provides specific examples illustrating the high-voltage connection detection circuit for electric vehicles provided in this application.

[0047] Figure 1 This is one of the structural schematic diagrams of the high-voltage connection detection circuit for an electric vehicle provided in the embodiments of this application, such as... Figure 1As shown, the high-voltage connection detection circuit of the electric vehicle includes a control module 1, a data acquisition module 2, and a processing module 3. The data acquisition module includes multiple first data acquisition units and multiple second data acquisition units. The control module 1 can be a controller composed of a microcontroller, and the processing module 3 can be a microprocessor.

[0048] First, it should be noted that in the power supply system of an electric vehicle, one end of multiple high-voltage branches is connected to the power battery, and the other end is connected to high-voltage equipment. The power battery can supply power to the high-voltage equipment through the high-voltage branches. In this embodiment, the input terminals of multiple first acquisition units are respectively used to connect to the first high-voltage connection points of multiple high-voltage branches in the power supply system of the electric vehicle. The first high-voltage connection point refers to the connection point between the high-voltage branch and the power battery. Based on this connection, the first acquisition unit can acquire the contact resistance value of the first high-voltage connection point.

[0049] The input terminals of multiple second acquisition units are respectively used to connect to the second high-voltage connection points of multiple high-voltage branches in the power supply system. The second high-voltage connection point refers to the connection point between the high-voltage branch and the high-voltage equipment. Based on this connection, the second acquisition unit can acquire the contact resistance value of the second high-voltage connection point.

[0050] The output terminals of multiple first acquisition units and multiple second acquisition units are all connected to the processing module. The first and second acquisition units can send the acquired contact resistance values ​​to the processing module. The processing module can determine whether the contact resistance values ​​of the first high-voltage connection point and the second high-voltage connection point are abnormal based on the contact resistance values. When abnormal, it is considered that the high-voltage connection point is loose and there is a risk of high-voltage connection.

[0051] The first high-voltage connection point of multiple high-voltage branches is also connected to the power battery through multiple relays. In this embodiment, the processing module is connected to the control module, and the control module is also connected to the control terminals of the multiple relays connected to the first high-voltage connection points of multiple high-voltage branches. The processing module can also send instructions to the control module so that the control module can control the relays to switch on and off based on the instructions, thereby controlling the connection or disconnection of the high-voltage branches and the power battery.

[0052] For example, when the contact resistance value of a high-voltage connection point is abnormal, the processing module sends a command to the control module. Based on the command, the control module controls the relay connected to the first high-voltage connection point of the high-voltage branch where the abnormal high-voltage connection point is located to disconnect. This disconnects the connection between the high-voltage branch and the power battery after the high-voltage connection point becomes abnormal, thus cutting off the power supply and preventing a larger fault caused by the abnormal contact resistance value.

[0053] In summary, the high-voltage connection detection circuit for electric vehicles provided in this embodiment can detect the contact resistance values ​​of high-voltage connection points of multiple high-voltage branches through the acquisition module. The processing module can determine whether the high-voltage connection points are working properly based on the acquired contact resistance values. Furthermore, in case of an abnormality, the control module can promptly disconnect the relay to ensure the safe use of the electric vehicle.

[0054] Figure 2 This is a second schematic diagram of the high-voltage connection detection circuit for an electric vehicle provided in an embodiment of this application, as shown below. Figure 2 As shown, the high-voltage connection detection circuit may also include a communication module 4, which may be, for example, a 4G communication module, a 5G communication module, or any other type of communication module.

[0055] Processing module 3 is connected to communication module 4. Communication module 4 is used to connect to the vehicle controller of the electric vehicle. Based on this connection, processing module 3 can send the analysis results to the vehicle controller (VCU) through communication module 4, so that the vehicle controller can take corresponding control measures for the electric vehicle based on the analysis results. For example, if the analysis results indicate that the contact resistance value of the high voltage connection point is abnormal during the vehicle's operation, the vehicle controller will determine that there is a risk to the vehicle's operation, control the vehicle to brake, and stop driving.

[0056] This application also provides specific implementation methods for the first acquisition unit and the second acquisition unit in the acquisition module. The first acquisition unit and the second acquisition unit can have the same structure. Figure 3 This is a schematic diagram of the structure of the first acquisition unit provided in an embodiment of this application.

[0057] like Figure 3 As shown, each first acquisition unit includes multiple first resistors (R1, R2, R3, and R4). The input terminal of each first acquisition unit is the first end of the multiple first resistors, which are all connected to the first high-voltage connection point of the same high-voltage branch. That is, the first ends of R1, R2, R3, and R4 are all connected to the first high-voltage connection point of the same high-voltage branch. The output terminal of each first acquisition unit is the second end of the multiple first resistors, which are respectively connected to the processing module (the second ends of R1, R2, R3, and R4 are all connected to the processing module).

[0058] The principle of the first acquisition unit is as follows: A known constant current source I1 (not shown in the figure) is connected to the second end of R1 and R4, allowing a known test current I1 to flow through the first high-voltage sampling point. Then, the voltage V1 at the first high-voltage connection point is measured. Based on the voltage V1 and the test current, the contact resistance value of the first high-voltage sampling point can be obtained. Specifically, R1 and R4 form a current loop, and R2 and R3 form a voltage test loop. The current loop provides a stable test current, and the voltage test loop is used to measure the voltage across the resistor under test. The impedance of the voltage test loop is very high, and the current through this loop is almost zero. Therefore, R2 and R3 will not affect the voltage test. Thus, the measured voltage V1 is the voltage at the first high-voltage connection point, and the contact resistance value of the first high-voltage sampling point can be calculated using the formula R = V1 / I1. The sensing current is the current generated by the resistance of the conductor itself, and its value is small, so its influence on the measurement result of the contact resistance value can be ignored.

[0059] Figure 4 This is a schematic diagram of the structure of the second acquisition unit provided in the embodiments of this application, as shown below. Figure 4 As shown, each second acquisition unit includes multiple second resistors (R5, R6, R7, and R8). The input terminal of each second acquisition unit is the first terminal of the multiple second resistors, all of which are connected to the second high-voltage connection point of the same high-voltage branch. That is, the first terminals of R5, R6, R7, and R8 are all connected to the second high-voltage connection point of the same high-voltage branch. The output terminal of each second acquisition unit is the second terminal of the multiple second resistors, which are respectively connected to the processing module (the second terminals of R5, R6, R7, and R8 are all connected to the processing module).

[0060] The principle of the second acquisition unit is as follows: A known constant current source I2 (not shown in the figure) is connected to the second end of R5 and R8, allowing a known test current I2 to flow through the second high-voltage sampling point. Then, the voltage V2 at the second high-voltage connection point is measured. Based on the voltage V2 and the test current, the contact resistance value of the second high-voltage sampling point can be obtained. Specifically, R5 and R8 form a current loop, and R6 and R7 form a voltage test loop. The current loop provides a stable test current, and the voltage test loop is used to measure the voltage across the resistor under test. The impedance of the voltage test loop is very high, and the current through this loop is almost zero. Therefore, R6 and R7 will not affect the voltage test. Thus, the measured voltage V2 is the voltage at the second high-voltage connection point, and the contact resistance value of the second high-voltage sampling point can be calculated using the formula R = V2 / I2. The sensing current is the current generated by the resistance of the conductor itself, and its value is small, so its influence on the measurement result of the contact resistance value can be ignored.

[0061] like Figure 5 As shown, the high-voltage connection detection circuit may also include multiple voltage divider resistors (in... Figure 5(represented by R in Chinese) The control module connects to the control terminals of multiple relays through multiple voltage divider resistors. The multiple voltage divider resistors can limit the current in their respective branches. By adjusting the resistance value of the voltage divider resistors, the current value of their respective branches can be adjusted to adapt to different usage requirements in actual application scenarios.

[0062] Figure 6 One of the structural schematic diagrams of the power supply system for the electric vehicle provided in this application is shown below. Figure 6 As shown, this application also provides a power supply system for an electric vehicle, including a power battery, multiple high-voltage branches, a battery management system, and a high-voltage connection detection circuit of any of the above embodiments.

[0063] The power battery has a first high-voltage connection point that connects to multiple high-voltage branches, and second high-voltage connection points that connect to multiple high-voltage devices. Based on this connection, the power battery can supply power to multiple high-voltage devices through multiple high-voltage branches. The power battery is also connected to a battery management system. Based on this connection, the battery management system can monitor the physical parameters of the power battery in real time, such as voltage, current, and temperature. It can also evaluate the state of the power battery through algorithms, such as state of charge (SOC), state of health (SOH), and state of power (SOP). Furthermore, it can control the charging and discharging of the power battery. For example, it can stop the charging and discharging operation when the temperature, voltage, or current of the power battery exceeds the safe range to prevent overcharging, over-discharging, overheating, and other situations from occurring.

[0064] In this embodiment, the input terminals of multiple first acquisition units in the high-voltage connection detection circuit are respectively connected to the first high-voltage connection points of multiple high-voltage branches (not shown in the figure), the input terminals of multiple second acquisition units in the high-voltage connection detection circuit are respectively connected to the second high-voltage connection points of multiple high-voltage branches (not shown in the figure), and the control module in the high-voltage connection detection circuit is also connected to the control terminals of multiple relays connected to the first high-voltage connection points of multiple high-voltage branches.

[0065] Specifically, such as Figure 7 As shown, multiple high-voltage branches may include a high-voltage main positive branch, a high-voltage charging branch, a high-voltage auxiliary drive branch, and a high-voltage main negative branch.

[0066] The first high-voltage connection point of the high-voltage main positive branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the positive terminal of at least one high-voltage load; the first high-voltage connection point of the high-voltage charging branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage charging branch is connected to the positive terminal of the high-voltage charging equipment; the first high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive terminal of the high-voltage auxiliary drive equipment; the first high-voltage connection point of the high-voltage main negative branch is connected to the negative terminal of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the negative terminal of all high-voltage equipment.

[0067] in, Figure 8 The schematic diagram of the high-voltage branch structure provided in this application is as follows: Figure 8 As shown, the high-voltage main positive branch includes high-voltage connection devices such as a manual service disconnect (MSD), a pre-charge relay, a pre-charge resistor, a main positive relay, and a fuse; the high-voltage charging branch includes high-voltage devices such as a fuse, a charging positive relay, and a charging negative relay; the high-voltage auxiliary drive branch includes fuses and auxiliary drive relays; and the high-voltage main negative branch includes a current sensor and a main negative relay.

[0068] After the electric vehicle starts, the battery management system detects data such as cell voltage and temperature of the power battery. Once the cell voltage and temperature data are normal, the system controls the closing of relays in each high-voltage branch to achieve discharge control of the power battery, enabling the power battery to supply power to the high-voltage equipment connected to each high-voltage branch.

[0069] Specifically, the main positive and negative relays control the on / off state of the entire circuit; the pre-charge relay and pre-charge resistor protect the circuit and its related components during startup; the charging positive and charging negative relays control the supply of power from the battery to the high-voltage charging equipment; and the auxiliary drive relay controls the supply of power from the battery to the high-voltage auxiliary drive equipment. After starting an electric vehicle, without a pre-charge relay, the main relay will directly connect to the capacitor. Because the battery voltage is high while the capacitor voltage is close to zero, this will cause a momentary short circuit, generating an extremely large current, potentially reaching tens of thousands of amperes. Such a current can damage the main relay and may even cause other electrical problems. Therefore, it is necessary to first close the pre-charge relay to charge the capacitor at the front end of the battery. After charging is complete, the main positive and negative relays are then closed to protect the circuit and related components.

[0070] When the relay is closed for the first time, multiple first acquisition units and multiple second acquisition units in the acquisition module start working, respectively acquiring the contact resistance value of the corresponding high-voltage connection point, and recording the acquired contact resistance value as the initial contact resistance value R1. The initial contact resistance value R1 is saved, and the relay is opened. After a preset time interval, the relay is controlled to close again, and the acquisition module acquires the contact resistance value of the corresponding high-voltage connection point again, which is recorded as the contact resistance value R2. R2 and R1 are compared. If R2 > 2R1, the processing module can report a warning information to the vehicle controller.

[0071] In one embodiment, such as Figure 9 As shown, multiple relays are also connected in parallel with multiple temperature control switches K. The temperature control switch is an automatic control element that produces a special effect by physical deformation inside the switch according to the temperature change of the working environment, thereby producing a conduction or disconnection action.

[0072] When the ambient temperature of a certain temperature control switch is higher than the preset value (for example, it can be higher than 30℃), the temperature control switch is turned on, and the first and second acquisition units corresponding to the high voltage branch can respectively acquire the contact resistance values ​​of the first high voltage connection point and the second high voltage connection point on the high voltage branch.

[0073] A temperature control switch can be installed to collect the contact resistance values ​​of the first and second high-voltage connection points on the branch when the temperature is too high, thereby determining whether the connection of the high-voltage connection points is normal based on the contact resistance value.

[0074] In one embodiment, the power battery can also be connected to the first high-voltage connection point of multiple high-voltage branches through multiple thermistors, and the multiple thermistors are communicatively connected to the battery management system.

[0075] The resistance of a thermistor is extremely sensitive to temperature changes. When the temperature of the high-voltage branch where the thermistor is located changes abnormally, the thermistor can report an early warning to the battery management system, further improving the safety of the power supply system.

[0076] In one embodiment, the power battery is also connected to the first high-voltage connection point of multiple high-voltage branches through multiple first amplification circuits, and the second high-voltage connection point of multiple high-voltage branches is also connected to multiple high-voltage devices through multiple second amplification circuits. The first amplification circuit and the second amplification circuit can amplify the differential voltage signal generated by the circuit under test, thereby improving the accuracy of the contact resistance value collected by the acquisition circuit.

[0077] The first amplifier circuit and the second amplifier circuit can have the same structure. Figure 10 This is a schematic diagram of the amplifier circuit provided in the embodiments of this application, such as... Figure 10As shown, R11 limits the current while achieving impedance matching in its branch; R12 limits the current; R13, R14 and R15 achieve impedance matching in their respective branches; capacitor C and R16 filter the current, and ZD stabilizes the voltage.

[0078] Optionally, the power supply system of this application may also include multiple anti-reverse diodes. The power battery is connected to the first high-voltage connection point of multiple high-voltage branches through multiple anti-reverse diodes. The anti-reverse diodes can prevent reverse current from flowing in and play a role in protecting the high-voltage branches.

[0079] In summary, the power supply system for electric vehicles provided in this application has the following advantages:

[0080] 1. By using the data acquisition module, the high-voltage connection points in the high-voltage branch are subjected to safety testing, which improves the operational stability and safety of the high-voltage branch.

[0081] 2. A temperature control switch is used. When the temperature of a high-voltage connection point in the high-voltage branch rises, the contact resistance value of that high-voltage connection point is re-measured and calculated. This reduces the calculations of the battery management system, lowers the design cost, and also ensures that the high-voltage connection point is safely detected when the temperature changes abnormally. This improves the detection reliability of the high-voltage connection point and reduces the risk of runaway.

[0082] 3. A thermistor is installed so that it can report to the battery management system when the temperature of the high-voltage connection point in the high-voltage branch is abnormal.

[0083] This application also provides an electric vehicle, which includes at least the vehicle body and the power supply system of the electric vehicle described above. The electric vehicle can perform connection safety detection on the high-voltage connection points of multiple high-voltage branches in its power supply system. High-voltage electricity can only be applied after the high-voltage connection points are connected normally, thus ensuring the safety of the electric vehicle.

[0084] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-voltage connection detection circuit for an electric vehicle, characterized in that, include: The system comprises a control module, a data acquisition module, and a processing module. The data acquisition module includes multiple first data acquisition units and multiple second data acquisition units. The input terminals of the plurality of first acquisition units are respectively used to connect to the first high-voltage connection points of the plurality of high-voltage branches in the power supply system of the electric vehicle, and the input terminals of the plurality of second acquisition units are respectively used to connect to the second high-voltage connection points of the plurality of high-voltage branches in the power supply system. The output terminals of the plurality of first acquisition units and the output terminals of the plurality of second acquisition units are all connected to the processing module. The processing module is connected to the control module. The control module is also connected to the control terminals of the plurality of relays connected to the first high-voltage connection points of the plurality of high-voltage branches.

2. The high-voltage connection detection circuit according to claim 1, characterized in that, Each first acquisition unit includes: multiple first resistors, the input terminal of each first acquisition unit is the first end of the multiple first resistors, all connected to the first high-voltage connection point of the same high-voltage branch, and the output terminal of each first acquisition unit includes: the second end of the multiple first resistors, which are respectively connected to the processing module; Each second acquisition unit includes: multiple second resistors, the input terminal of each second acquisition unit is the first terminal of the multiple second resistors, all connected to the second high-voltage connection point of the same high-voltage branch, and the output terminal of each second acquisition unit includes: the second terminal of the multiple second resistors, which are respectively connected to the processing module.

3. The high-voltage connection detection circuit according to claim 1, characterized in that, The high-voltage connection detection circuit also includes: multiple voltage divider resistors; The control module is connected to the control terminals of the multiple relays through the multiple voltage divider resistors.

4. The high-voltage connection detection circuit according to claim 1, characterized in that, The high-voltage connection detection circuit further includes a communication module, the processing module is connected to the communication module, and the communication module is used to connect to the vehicle controller of the electric vehicle.

5. A power supply system for an electric vehicle, characterized in that, include: The system comprises a power battery, multiple high-voltage branches, a battery management system, and a high-voltage connection detection circuit as described in any one of claims 1-4; the power battery is connected to a first high-voltage connection point of the multiple high-voltage branches, the second high-voltage connection points of the multiple high-voltage branches are respectively used to connect to multiple high-voltage devices, and the power battery is also connected to the battery management system. In the high-voltage connection detection circuit, the input terminals of multiple first acquisition units are respectively connected to the first high-voltage connection points of the multiple high-voltage branches, the input terminals of multiple second acquisition units are respectively connected to the second high-voltage connection points of the multiple high-voltage branches, and the control module in the high-voltage connection detection circuit is also connected to the control terminals of multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

6. The power supply system according to claim 5, characterized in that, The multiple relays are also connected in parallel with multiple temperature control switches.

7. The power supply system according to claim 5, characterized in that, The power battery is connected to the first high-voltage connection point of the multiple high-voltage branches through multiple thermistors, and the multiple thermistors are connected to the battery management system.

8. The power supply system according to claim 5, characterized in that, The power battery is connected to the first high-voltage connection point of the multiple high-voltage branches through multiple first amplification circuits, and the second high-voltage connection point of the multiple high-voltage branches is connected to the multiple high-voltage devices through multiple second amplification circuits.

9. The power supply system according to claim 5, characterized in that, The multiple high-voltage branches include: high-voltage main positive branch, high-voltage charging branch, high-voltage auxiliary drive branch, and high-voltage main negative branch; The first high-voltage connection point of the high-voltage main positive branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the positive terminal of at least one high-voltage load. The first high-voltage connection point of the high-voltage charging branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage charging branch is connected to the positive terminal of the high-voltage charging equipment. The first high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive terminal of the power battery, and the second high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive terminal of the high-voltage auxiliary drive equipment. The first high-voltage connection point of the high-voltage main negative branch is connected to the negative terminal of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the negative terminal of all high-voltage equipment.

10. An electric vehicle, characterized in that, At least including: The vehicle body and the power supply system of the electric vehicle according to any one of claims 5-9.

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