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

Abstract

The invention 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] The present application relates to the field of vehicle technology, and in particular to a high-voltage connection detection circuit, a power supply system and an electric vehicle for an electric vehicle. Background Art

[0002] With the development of new energy technologies, electric vehicles have become increasingly popular, and issues related to the safety of electric vehicle use have received increasing attention.

[0003] The power supply system of electric vehicles usually contains multiple high-voltage branches. Whether the connection points of these high-voltage branches can work reliably is directly related to the safety of electric vehicles. Therefore, how to conduct safety detection of high-voltage connection points is a difficult problem that needs to be solved urgently. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present application provides a high-voltage connection detection circuit, a power supply system and an electric vehicle for an electric vehicle, so as to solve the problems existing in the prior art.

[0005] The technical solution adopted in the embodiment of the present application is as follows: In a first aspect, an embodiment of the present application provides a high-voltage connection detection circuit for an electric vehicle, including: a control module, a collection module, and a processing module, wherein the collection module includes: a plurality of first collection units and a plurality of second collection units; The input ends 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 ends 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 ends of the multiple first acquisition units and the output ends of the multiple second acquisition units are both connected to the processing module, the processing module is connected to the control module, and the control module is also connected to the control ends of the multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

[0006] In one embodiment, each of the first acquisition units includes: a plurality of first resistors, the input end of each of the first acquisition units is the first ends of the plurality of first resistors, all connected to the first high-voltage connection point of the same high-voltage branch, and the output end of each of the first acquisition units includes: the second ends of the plurality of first resistors, respectively connected to the processing modules; Each of the second acquisition units includes: multiple second resistors, the input end of each of the second acquisition units is the first ends of the multiple second resistors, all connected to the second high-voltage connection point of the same high-voltage branch, and the output end of each of the second acquisition units includes: the second ends of the multiple second resistors, respectively connected to the processing modules.

[0007] In one embodiment, the high voltage connection detection circuit further includes: a plurality of voltage dividing resistors; The control module is connected to the control ends of the plurality of relays through the plurality of voltage-dividing resistors.

[0008] In one embodiment, 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 a vehicle controller of the electric vehicle.

[0009] In a second aspect, an embodiment of the present application provides a power supply system for an electric vehicle, comprising: a power battery, a plurality of high-voltage branches, a battery management system, and the high-voltage connection detection circuit described in the above embodiment; the power battery is connected to a first high-voltage connection point of the plurality of high-voltage branches, the second high-voltage connection points of the plurality of high-voltage branches are respectively used to connect a plurality of high-voltage devices, and the power battery is also connected to the battery management system; Among them, the input ends of multiple first acquisition units in the high-voltage connection detection circuit are respectively connected to the first high-voltage connection points of the multiple high-voltage branches, the input ends of multiple second acquisition units in the high-voltage connection detection circuit 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 ends of multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

[0010] In one embodiment, the plurality of relays are further connected in parallel with a plurality of temperature control switches respectively.

[0011] In one embodiment, the power batteries are connected to the first high-voltage connection points of the plurality of high-voltage branches through a plurality of thermistors, respectively, and the plurality of thermistors are connected to the battery management system.

[0012] In one embodiment, the power battery is connected to the first high-voltage connection points of the multiple high-voltage branches through a plurality of first amplifying circuits, respectively, and the second high-voltage connection points of the multiple high-voltage branches are connected to the multiple high-voltage devices through a plurality of second amplifying circuits, respectively.

[0013] 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; Wherein, the first high-voltage connection point of the high-voltage main positive branch is connected to the positive electrode of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the positive electrode of at least one high-voltage load; The first high-voltage connection point of the high-voltage charging branch is connected to the positive electrode of the power battery, and the second high-voltage connection point of the high-voltage charging branch is connected to the positive electrode of the high-voltage charging device; The first high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive electrode of the power battery, and the second high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive electrode of the high-voltage auxiliary drive device; The first high-voltage connection point of the high-voltage main negative branch is connected to the negative electrode of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the negative electrodes of all high-voltage devices.

[0014] In a third aspect, an embodiment of the present application provides an electric vehicle, which comprises at least a vehicle body and a power supply system of the electric vehicle described in the above embodiment.

[0015] The beneficial effects of the present application are as follows: the present application provides a high-voltage connection detection circuit for an electric vehicle, comprising a control module, an acquisition module, and a processing module, the acquisition module comprising multiple first acquisition units and multiple second acquisition units; the input ends of the 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, and the input ends of the 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 output ends of the multiple first acquisition units and the output ends of the multiple second acquisition units are both connected to the processing module, the processing module is connected to the control module, and the control module is also connected to the control ends of multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

[0016] The high-voltage connection detection circuit of the electric vehicle provided in the present application can detect the contact resistance of the high-voltage connection points of multiple high-voltage branches through the acquisition module and the processing module, so as to determine whether the high-voltage connection points are working normally to ensure the safe use of the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 One of the structural schematic diagrams of the high-voltage connection detection circuit of the electric vehicle provided in the embodiment of the present application; Figure 2 A second structural schematic diagram of a high-voltage connection detection circuit for an electric vehicle provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of a first acquisition unit provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of a second acquisition unit provided in an embodiment of the present application; Figure 5The third structural diagram of the high-voltage connection detection circuit of the electric vehicle provided in the embodiment of the present application; Figure 6 One of the structural schematic diagrams of the power supply system of the electric vehicle provided in this application; Figure 7 The second structural schematic diagram of the power supply system of the electric vehicle provided in this application; Figure 8 A schematic diagram of the high-voltage branch structure provided for this application; Fig. 9 The third structural schematic diagram of the power supply system of the electric vehicle provided in this application; Fig.10 This is a schematic diagram of the structure of the amplifier circuit provided in this application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0021] In the description of the present application, it should be noted that if the terms "upper", "lower", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0022] In addition, the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a direct connection, it can be an indirect connection through an intermediate medium, and it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] It should be noted that, in the absence of conflict, the features in the embodiments of the present application may be combined with each other.

[0025] The power supply system of an electric vehicle generally includes multiple high-voltage branches, such as a discharge circuit, a charging circuit, an auxiliary drive circuit, etc. After the electric vehicle has been running for a long time, the high-voltage connection points in these high-voltage branches may become loose, resulting in increased contact resistance at the connection points and an increased 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 the vehicle users.

[0026] In response to the above problems, the present application provides a high-voltage connection detection circuit for an electric vehicle. The high-voltage connection detection circuit for an electric vehicle provided by the present application is specifically described below through multiple examples in conjunction with the accompanying drawings.

[0027] Figure 1 This is one of the structural schematic diagrams of the high-voltage connection detection circuit of the electric vehicle provided in the embodiment of the present application, such as Figure 1 As shown, the high voltage connection detection circuit of the electric vehicle includes a control module 1, a collection module 2, and a processing module 3. The collection module includes a plurality of first collection units and a plurality of second collection units. Among them, the control module 1 can be a controller composed of a single chip microcomputer, and the processing module 3 can be a microprocessor.

[0028] First of all, it should be noted that in the power supply system of the electric vehicle, one end of the multiple high-voltage branches is connected to the power battery, and the other end is connected to the high-voltage equipment. The power battery can supply power to the high-voltage equipment through the high-voltage branches. In this embodiment, the input ends of the multiple first acquisition units are respectively used to connect the first high-voltage connection points of the 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 collect the contact resistance value of the first high-voltage connection point.

[0029] The input ends of multiple second acquisition units are respectively used to connect 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 collect the contact resistance value of the second high-voltage connection point.

[0030] The output ends of multiple first acquisition units and the output ends of multiple second acquisition units are all connected to the processing module. The first acquisition unit and the second acquisition unit can send the collected 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.

[0031] The first high-voltage connection points of the multiple high-voltage branches are also connected to the power battery through multiple relays. The processing module of this embodiment is connected to the control module, and the control module is also connected to the control ends of the multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches. The processing module can also send instructions to the control module so that the control module can control the on and off of the relays based on the instructions, thereby controlling the connection or disconnection of the high-voltage branch and the power battery.

[0032] For example, when the contact resistance value of a certain high-voltage connection point is abnormal, the processing module sends an instruction to the control module. Based on the instruction, 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. Therefore, after the high-voltage connection point becomes abnormal, the connection between the high-voltage branch and the power battery is cut off, thereby cutting off the power supply to avoid greater faults caused by the abnormal contact resistance value.

[0033] In summary, the high-voltage connection detection circuit of the electric vehicle provided in this embodiment can detect the contact resistance values ​​of the high-voltage connection points of multiple high-voltage branches through the acquisition module, and the processing module can determine whether the high-voltage connection points are working normally based on the collected contact resistance values. In addition, when an abnormality occurs, the relay can be cut off in time through the control module to ensure the safe use of the electric vehicle.

[0034] Figure 2 The second structural diagram of the high-voltage connection detection circuit of the electric vehicle provided in the embodiment of the present application is as follows: Figure 2 As shown, the high-voltage connection detection circuit may further 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.

[0035] The processing module 3 is connected to the communication module 4, and the communication module 4 is used to connect to the vehicle controller of the electric vehicle. Based on this connection, the processing module 3 can send the analysis results to the vehicle control unit (VCU) through the communication module 4, so that the vehicle controller can make corresponding control measures for the electric vehicle based on the analysis results. For example, if the analysis result indicates that the contact resistance value of the high-voltage connection point is abnormal during the driving of the vehicle, the vehicle controller determines that the vehicle has a driving risk, controls the vehicle to brake, and stops driving.

[0036] The present application also provides a specific implementation of the first acquisition unit and the second acquisition unit in the acquisition module. The structures of the first acquisition unit and the second acquisition unit may be the same. Figure 3 A schematic diagram of the structure of the first acquisition unit provided in an embodiment of the present application.

[0037] like Figure 3 As shown, each first acquisition unit includes multiple first resistors (R1, R2, R3 and R4), the input end of each first acquisition unit is the first ends of the multiple first resistors, 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, and the output end of each first acquisition unit is the second ends of the multiple first resistors, which are respectively connected to the processing modules (the second ends of R1, R2, R3 and R4 are all connected to the processing module).

[0038] The principle of the first acquisition unit is: connect a known constant current source I1 (not shown in the figure) to the second end of R1 and R4, make the first high-voltage sampling point flow through a test current I1 of known magnitude, and then measure the voltage V1 of the first high-voltage connection point. According to 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. The voltage test loop is used to measure the voltage on the resistor to be tested. The impedance of the voltage test loop is very high, and the current passing through this loop is almost zero. Therefore, R2 and R3 will not affect the voltage test. In this way, the measured voltage V1 is the voltage of 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 wire itself, and the value is small, and the impact on the measurement result of the contact resistance value can be ignored.

[0039] Figure 4A schematic diagram of the structure of the second acquisition unit provided in the embodiment of the present application, such as Figure 4 As shown, each second acquisition unit includes multiple second resistors (R5, R6, R7 and R8), the input end of each second acquisition unit is the first ends of the multiple second resistors, all connected to the second high-voltage connection point of the same high-voltage branch, that is, the first ends of R5, R6, R7 and R8 are all connected to the second high-voltage connection point of the same high-voltage branch, and the output end of each second acquisition unit is the second ends of the multiple second resistors, respectively connected to the processing module (the second ends of R5, R6, R7 and R8 are all connected to the processing module).

[0040] The principle of the second acquisition unit is: connect a known constant current source I2 (not shown in the figure) to the second end of R5 and R8, make the second high-voltage sampling point flow through a test current I2 of known size, then measure the voltage V2 of the second high-voltage connection point, and then obtain the contact resistance value of the second high-voltage sampling point according to the voltage V2 and the test current. 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. The voltage test loop is used to measure the voltage on the resistor to be tested. The impedance of the voltage test loop is very high, and the current passing through this loop is almost zero. Therefore, R6 and R7 will not affect the voltage test. In this way, the measured voltage V2 is the voltage of 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 wire itself, and the value is small, and the impact on the measurement result of the contact resistance value can be ignored.

[0041] like Figure 5 As shown, the high voltage connection detection circuit may further include a plurality of voltage dividing resistors (in Figure 5 The control module is connected to the control ends of multiple relays through multiple voltage-dividing resistors. The multiple voltage-dividing resistors can limit the current of the branch where they are located. By adjusting the resistance value of the voltage-dividing resistor, the current value of the branch where they are located can be adjusted to adapt to different usage requirements in actual application scenarios.

[0042] Figure 6 One of the structural schematic diagrams of the power supply system of the electric vehicle provided in this application is as follows: Figure 6 As shown, the present application also provides a power supply system for an electric vehicle, including a power battery, a plurality of high-voltage branches, a battery management system, and a high-voltage connection detection circuit of any of the above embodiments.

[0043] The power battery is connected to the first high-voltage connection points of multiple high-voltage branches, and the second high-voltage connection points of the multiple high-voltage branches are respectively used to connect multiple high-voltage devices. Based on this connection, the power battery can supply power to multiple high-voltage devices through multiple high-voltage branches respectively; the power battery is also connected to the battery management system. Based on this connection, the battery management system can monitor the physical parameters such as voltage, current, temperature, etc. of the power battery in real time, and can also evaluate the status of the power battery through algorithms, such as state of charge (SOC), state of health (SOH), state of power (SOP), etc., and can also control the charging and discharging of the power battery. For example, when the temperature, voltage or current of the power battery exceeds a safe range, the charging and discharging operation can be stopped to prevent the power battery from being overcharged, over-discharged, overheated, etc.

[0044] In this embodiment, the input ends 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 ends 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 ends of multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

[0045] Specifically, Figure 7 As shown, the 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.

[0046] The first high-voltage connection point of the high-voltage main positive branch is connected to the positive electrode of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the positive electrode of at least one high-voltage load; the first high-voltage connection point of the high-voltage charging branch is connected to the positive electrode of the power battery, and the second high-voltage connection point of the high-voltage charging branch is connected to the positive electrode of the high-voltage charging equipment; the first high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive electrode of the power battery, and the second high-voltage connection point of the high-voltage auxiliary drive branch is connected to the positive electrode 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 electrode of the power battery, and the second high-voltage connection point of the high-voltage main positive branch is connected to the negative electrodes of all high-voltage equipment.

[0047] in, Figure 8 The high voltage branch structure diagram provided for 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-charging relay, a pre-charging 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 a fuse, an auxiliary drive relay, etc.; the high-voltage main negative branch includes a current sensor and a main negative relay.

[0048] After the electric vehicle is started, the battery management system detects the cell voltage, temperature and other data of the power battery. When the cell voltage and temperature data are normal, the discharge of the power battery is controlled by controlling the closure of the relays in each high-voltage branch, so that the power battery can supply power to the high-voltage equipment connected to each high-voltage branch.

[0049] Specifically, the main positive relay and the main negative relay are used to control the on and off of the entire circuit; the pre-charge relay and the pre-charge resistor are used to protect the circuit and its related components when the circuit is started; the charging positive relay and the charging negative relay are used to control the on and off of the power battery for the high-voltage charging equipment; the auxiliary drive relay is used to control the on and off of the power battery for the high-voltage auxiliary drive equipment. After the electric vehicle is started, if there is no pre-charge relay, the main relay will be directly connected to the capacitor. Since the battery voltage is high and the voltage on the capacitor is close to zero, this will cause an instantaneous short circuit and generate a huge current, which may reach tens of thousands of amperes. Such a current will cause damage to the main relay and may even cause other electrical problems. Therefore, it is necessary to close the pre-charge relay first to charge the capacitor at the front end of the battery. After charging is completed, the main positive relay and the main negative relay are closed to protect the circuit and related components.

[0050] 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 acquire the contact resistance values ​​of the corresponding high-voltage connection points, and record the acquired contact resistance values ​​as the initial contact resistance values ​​R1. The initial contact resistance value R1 is saved, and the relay is disconnected. After a preset time interval, the relay is controlled to close again, and the acquisition module once again acquires the contact resistance values ​​of the corresponding high-voltage connection points, recorded as the contact resistance values ​​R2. R2 is compared with R1. If R2>2R1, the processing module can report warning information to the vehicle controller.

[0051] In one embodiment, if Fig. 9 As shown, the 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 conduction or disconnection action by causing physical deformation inside the switch according to the temperature change of the working environment, thereby producing certain special effects.

[0052] When the ambient temperature of a temperature-controlled switch is higher than a preset value (for example, higher than 30°C), the temperature-controlled switch is turned on, and the first acquisition unit and the second acquisition unit corresponding to the high-voltage branch can respectively collect the contact resistance values ​​of the first high-voltage connection point and the second high-voltage connection point on the high-voltage branch.

[0053] By setting a temperature control switch, when the temperature is too high, the contact resistance values ​​of the first high-voltage connection point and the second high-voltage connection point on the branch can be collected, so as to judge whether the connection status of the high-voltage connection point is normal based on the contact resistance value.

[0054] In one embodiment, the power battery may also be connected to the first high-voltage connection points of the plurality of high-voltage branches through a plurality of thermistors respectively, and the plurality of thermistors are communicatively connected to the battery management system.

[0055] The resistance value of the 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.

[0056] In one embodiment, the power battery is also connected to the first high-voltage connection points of the multiple high-voltage branches through multiple first amplifying circuits, and the second high-voltage connection points of the multiple high-voltage branches are also connected to the multiple high-voltage devices through multiple second amplifying circuits. The first amplifying circuit and the second amplifying circuit can amplify the pressure difference signal generated by the measured circuit, thereby improving the accuracy of the contact resistance value collected by the acquisition circuit.

[0057] The first amplifier circuit and the second amplifier circuit may have the same structure. Fig.10 A schematic diagram of the structure of the amplifier circuit provided in the embodiment of the present application is shown in FIG. Fig.10 As shown, the role of R11 is to achieve impedance matching in the branch where it is located while limiting the current; the role of R12 is current limiting; the role of R13, R14 and R15 is to achieve impedance matching in the branch where they are located; the role of capacitors C and R16 is filtering, and the role of ZD is voltage stabilization.

[0058] Optionally, the power supply system of the present application may further include multiple anti-reverse diodes, and the power battery is respectively connected to the first high-voltage connection points of multiple high-voltage branches through multiple anti-reverse diodes. The anti-reverse diodes can prevent reverse current from flowing in, thereby protecting the high-voltage branches.

[0059] In summary, the power supply system of the electric vehicle provided in this application has the following advantages: 1. Through the acquisition module, the high-voltage connection points in the high-voltage branch are safely detected to improve the operating stability and safety of the high-voltage branch.

[0060] 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 the high-voltage connection point is recalculated, which reduces the calculation of the battery management system and reduces the design cost. At the same time, it also ensures that the high-voltage connection point is safely detected when the temperature changes abnormally, improves the detection reliability of the high-voltage connection point, and reduces the risk of loss of control.

[0061] 3. A thermistor is set up, and when the temperature of the high-voltage connection point in the high-voltage branch is abnormal, it can report to the battery management system.

[0062] An embodiment of the present application also provides an electric vehicle, comprising at least a vehicle body and the power supply system of the electric vehicle of the above embodiment, wherein the electric vehicle can perform connection safety detection on the high-voltage connection points of multiple high-voltage branches in its power supply system, and high voltage electricity can only be supplied after the high-voltage connection points are connected normally, thereby ensuring the safe use of the electric vehicle.

[0063] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A high voltage connection detection circuit for an electric vehicle, characterized in that: include: A control module, a collection module, and a processing module, wherein the collection module includes: a plurality of first collection units and a plurality of second collection units; The input ends 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 ends 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 ends of the multiple first acquisition units and the output ends of the multiple second acquisition units are both connected to the processing module, the processing module is connected to the control module, and the control module is also connected to the control ends of the multiple relays connected to the first high-voltage connection points of the multiple high-voltage branches.

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

3. The high voltage connection detection circuit according to claim 1, characterized in that: The high voltage connection detection circuit further includes: a plurality of voltage dividing resistors; The control module is connected to the control ends of the plurality of relays through the plurality of voltage-dividing 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 a vehicle controller of the electric vehicle.

5. A power supply system for an electric vehicle, characterized in that: include: A power battery, a plurality of high-voltage branches, a battery management system, and a high-voltage connection detection circuit according to any one of claims 1 to 4; the power battery is connected to a first high-voltage connection point of the plurality of high-voltage branches, the second high-voltage connection points of the plurality of high-voltage branches are respectively used to connect a plurality of high-voltage devices, and the power battery is also connected to the battery management system; Among them, the input ends of multiple first acquisition units in the high-voltage connection detection circuit are respectively connected to the first high-voltage connection points of the multiple high-voltage branches, the input ends of multiple second acquisition units in the high-voltage connection detection circuit 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 ends 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 plurality of relays are also respectively connected in parallel with a plurality of temperature control switches.

7. The power supply system according to claim 5, characterized in that: The power batteries are connected to the first high-voltage connection points of the multiple high-voltage branches through multiple thermistors, respectively, 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 points of the multiple high-voltage branches through a plurality of first amplifying circuits, respectively, and the second high-voltage connection points of the multiple high-voltage branches are connected to the multiple high-voltage devices through a plurality of second amplifying circuits, respectively.

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

10. An electric vehicle, characterized in that: At least: A vehicle body and a power supply system for an electric vehicle as described in claim 5 above.

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