A charging control circuit, a charging system and an electric vehicle

Abstract

This application provides a charging control circuit, a charging system, and an electric vehicle. The charging control circuit consists of an analog circuit, including: a reverse protection module that receives and unidirectionally transmits a charger signal input from the charger signal input terminal; a signal conditioning module that receives the charger signal output from the reverse protection module and conditions it into a charging control drive signal, wherein the voltage of the charging control drive signal is lower than that of the charger signal; a charging control drive module that receives the charging control drive signal output from the signal conditioning module and conditions it into a charging control signal; and a charging control module including at least one switching device connected to the charger negative terminal and the battery negative terminal, the state of which is controlled by the charging control signal. The technical solution provided by this application reduces the risk of electric shock to users and improves the safety of the electric vehicle charging system while ensuring battery charging efficiency.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a charging control circuit, a charging system, and an electric vehicle. Background Technology

[0002] With the rapid development of the electric vehicle market, the requirements for vehicle charging system design are becoming increasingly stringent. As a core component of the electric vehicle charging system, the charging control circuit plays a crucial role in ensuring battery charging efficiency and user safety. Therefore, how to provide technical solutions to improve battery charging efficiency and user safety in the charging control circuit has become a pressing technical problem for those skilled in the art. Utility Model Content

[0003] To address the aforementioned technical problems, embodiments of this application provide a charging control circuit, a charging system, and an electric vehicle, thereby reducing the risk of electric shock to users and improving the safety of the electric vehicle's charging system while ensuring battery charging efficiency.

[0004] In a first aspect, embodiments of this application provide a charging control circuit that does not include any digital devices, the charging control circuit comprising:

[0005] The reverse protection module receives the charger signal input from the charger signal input terminal and transmits it unidirectionally.

[0006] The signal conditioning module receives the charger signal output from the output terminal of the reverse protection module and conditions it into a charging control drive signal, wherein the voltage of the charging control drive signal is less than that of the charger signal.

[0007] The charging control drive module receives the charging control drive signal output by the signal conditioning module and conditions it into a charging control signal;

[0008] The charging control module includes at least one switching device, which is connected to the negative terminal of the charger and the negative terminal of the battery, and the state of the switching device is controlled by the charging control signal.

[0009] Secondly, embodiments of this application provide a charging system, including:

[0010] The charging control circuit as described in the first aspect;

[0011] A charger, wherein the charger is connected to a positive terminal, a signal terminal, and a negative terminal;

[0012] A battery, wherein the battery is connected to a positive terminal, a wake-up signal terminal, and a negative terminal;

[0013] The charging port is connected to the charger signal input terminal and the charger signal terminal, the charger negative terminal and the charger negative terminal connection terminal, and the charger positive terminal and the battery positive terminal;

[0014] The charger is pluggably connected to the charging port.

[0015] Thirdly, embodiments of this application provide an electric vehicle including the charging system described in the second aspect.

[0016] The charging control circuit provided in this application embodiment receives a charger signal through the charger signal input terminal. Since the voltage of the charger signal is relatively high, it needs to be conditioned into a charging control drive signal by passing through a reverse protection module and a signal conditioning module in sequence. The voltage of the charging control drive signal is lower than that of the charger signal. Then, the charging control drive module conditions the charging control drive signal into a charging control signal, and controls the state of at least one switching device in the charging control module through the charging control signal, thereby controlling the on / off state of the charger negative terminal and the battery negative terminal.

[0017] When the charger is connected to the charging control circuit, the charger signal provided by the charger is conditioned into a charging control signal by the reverse protection module, signal conditioning module, and charging control drive module, which connects the negative terminal of the charger and the negative terminal of the battery, thus starting to charge the battery. When the charger is disconnected from the charging control circuit, the path between the negative terminal of the charger and the negative terminal of the battery is broken, so that no voltage is measured between the charger signal input terminal and the negative terminal of the charger, ensuring user safety. Furthermore, since the charging control circuit is composed of analog circuits, that is, all the components in the charging control circuit are analog devices, the switching speed of the charging circuit when the charger switches between connected and disconnected is improved, the battery charging efficiency in the charging control circuit is improved, and user safety is further enhanced. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a charging control circuit provided in an embodiment of this application.

[0020] Figure 2 This is another schematic diagram of a charging control circuit provided in an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of a charging control system provided in an embodiment of this application. Detailed Implementation

[0022] As described in the background section, the battery charging efficiency and user safety in charging control circuits need improvement. The reasons why the battery charging efficiency and user safety in charging control circuits need improvement are explained below.

[0023] Some electric vehicles are charged by connecting to external charging devices. These devices connect to the charging control circuitry in the electric vehicle by plugging into its charging port, and then charge the battery.

[0024] Since the charging port of an electric vehicle typically transmits high voltage and high current, and is a key interface for connecting the electric vehicle to external charging devices such as chargers and charging guns, in order to reduce the risk of electric shock to users, no voltage should be measured between the positive and negative terminals of the charging port. That is, there is no high voltage circuit between the positive and negative terminals of the charging port of an electric vehicle.

[0025] To reduce the risk of electric shock to users, one approach is to place a diode at the positive input terminal of the charging port. After an external charging device is connected to the electric vehicle's charging port, the charging current is allowed to flow unidirectionally through the charging control circuit to the vehicle's battery, but the current is not allowed to flow backwards from the battery. However, placing a diode in the charging path reduces the battery charging efficiency of the charging control circuit. Specifically, because there is a forward voltage drop when the diode is conducting, the battery voltage will always be lower than the charging voltage provided by the external charging device, thus affecting the battery's charging efficiency. Furthermore, when the diode breaks down and fails, it does not reduce the risk of electric shock to users, and its stability needs improvement.

[0026] In addition, if a sensor is added to the charging port, when an external charging device is connected to the charging port (i.e. when the charging port is open), the battery charging circuit needs to be opened through the electric vehicle's control system. The disadvantage is that it is more complicated and needs to be controlled by the control system, and the response speed needs to be improved.

[0027] Therefore, embodiments of this application provide a charging control circuit, a charging system, and an electric vehicle to reduce the risk of electric shock to users and improve the safety of the charging system of electric vehicles while ensuring battery charging efficiency.

[0028] 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 only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Figure 1 This is a schematic diagram of a charging control circuit provided in an embodiment of this application. Figure 1 As shown, the charging control circuit 10 is composed of analog circuits, including:

[0030] The reverse protection module 110 receives the charger signal input from the charger signal input terminal 101 and transmits it unidirectionally. When the charger is connected to the charging control circuit 10, the charger signal port of the charger is connected to the charger signal input terminal 101, and the negative port of the charger is connected to the charger negative connection terminal 102. In some embodiments, the voltage of the charger signal input to the charger signal input terminal 101 is higher than 36V; specifically, it can be the same as the voltage of the charger. For example, when the voltage of the charger is 72V, the voltage of the charger signal is also 72V.

[0031] The signal conditioning module 120 receives the charger signal output from the output terminal of the reverse protection module 110 and conditions it into a charging control drive signal. The voltage of the charging control drive signal is lower than that of the charger signal. Since the voltage of the charger signal is too high to directly drive subsequent switching devices, the high-voltage charger signal output from the output terminal of the reverse protection module 110 needs to be conditioned into a low-voltage charging control drive signal.

[0032] The charging control drive module 130 receives the charging control drive signal output by the signal conditioning module 120 and conditions it into a charging control signal. Since the power of the charging control drive signal is low, the charging control drive module 130 needs to amplify the power of the charging control drive signal so that subsequent switching devices can control the on / off state of the charging circuit.

[0033] The charging control module 140 includes at least one switching device connected to the negative terminal 102 of the charger and the negative terminal 152 of the battery. The state of the switching device is controlled by the charging control signal. When the negative terminal 102 of the charger and the negative terminal 152 of the battery are connected, a path is formed between the negative terminals of the charger and the negative terminal of the battery, thereby enabling the charger connected to the charging control circuit 10 to charge the battery.

[0034] Figure 2This is another schematic diagram of a charging control circuit provided in an embodiment of this application. (Reference) Figure 1 and Figure 2 In some embodiments, the reverse protection module 110 includes:

[0035] The anode of the first diode D4 is connected to the signal input terminal 101 of the charger; one end of the first resistor R11 is connected to the cathode of the first diode D4; the anode of the second diode D7 is connected to the first resistor R11, and its cathode is connected to the signal conditioning module 120.

[0036] The first diode D4 and the second diode D7 are used to ensure the unidirectional flow of the charging identification signal provided by the charging identification signal port included in the charger signal input terminal 101 after it is input into the reverse protection module 110. The first resistor R11 is used to limit the current and prevent the first diode D4 and the second diode D7 from being overloaded and burning out, which would affect the reliability of the charging control circuit 10.

[0037] In some embodiments, the charging control circuit 10 further includes a charger signal output terminal 151, and the reverse protection module 110 further includes: a ninth resistor R15 connected to the cathode of the first diode D4; and a fourth diode D6, the anode of which is connected to the ninth resistor R15 and the cathode of which is connected to the charger signal output terminal 151.

[0038] Since the battery enters a dormant state when not in use for a long time, a battery wake-up signal output from the charger signal output terminal 151 (i.e., port 72V_O) is needed to wake the battery and enable the charging control circuit 10 to charge it. The fourth diode D6 ensures unidirectional signal flow, and the ninth resistor R15 limits the current to prevent the fourth diode D6 from burning out and failing to wake the battery, thus ensuring the reliability of the charging control circuit 10.

[0039] Continue to refer to Figure 1 and Figure 2 In some embodiments, the signal conditioning module 120 includes:

[0040] A first voltage divider unit is connected to the reverse protection module 110. The first voltage divider unit includes a second resistor R12, a third resistor R17, and a fourth resistor R19 connected in parallel. The second resistor R12, the third resistor R17, and the fourth resistor R19 are used to divide the charger signal output by the reverse protection module 110. In some specific embodiments, the charger signal output by the reverse protection module 110 is 72V, and the resistance values ​​of the second resistor R12, the third resistor R17, and the fourth resistor R19 are 330Ω, 51kΩ, and 1MΩ, respectively.

[0041] A signal conditioning circuit is connected to the first voltage divider unit. The signal conditioning circuit includes a first transistor Q7 and a second transistor Q6. The base of the first transistor Q7 is connected to the fourth resistor R19, the collector is connected to the third resistor R17, and the emitter is connected to the base of the second transistor Q6. The base of the second transistor Q6 is connected to the second resistor R12, and the emitter is connected to a fifth resistor R13.

[0042] In this configuration, the base of the first transistor Q7 is connected to the fourth resistor R19, allowing the voltage across the fourth resistor R19 to control the state of the first transistor Q7. When the first transistor Q7 is on, the base of the second transistor Q6 is connected to the third resistor R17, allowing the voltage across the third resistor R17 to control the state of the second transistor Q6. The charging control drive signal is the signal output by the signal conditioning module 120 when the second transistor Q6 is on. The fifth resistor R13 is used to adjust the current of the charging control drive signal. In some specific embodiments, the resistance value of the fifth resistor R13 is 1000Ω.

[0043] The first protection unit has its two ends connected to the base of the first transistor Q7 and the negative terminal of the battery, respectively. The first protection unit includes a first clamping diode DZ3 and a first capacitor C4 connected in parallel. The cathode of the first clamping diode DZ3 is connected to the base of the first transistor Q7 and one end of the first capacitor C4, while the anode of the first clamping diode DZ3 is connected to the other end of the first capacitor C4 and the negative terminal of the battery. The first clamping diode DZ3 is used for voltage regulation and, together with the first capacitor C4, prevents rapid changes in the on / off state of the signal conditioning module 120 caused by voltage variations in the charger signal, thus ensuring the stability of the charging control circuit 10.

[0044] It should also be noted that the SYS- terminal connected to the anode of the first clamping diode DZ3 is used to connect to the negative terminal of the control system of the electric vehicle where the charging control circuit 10 is located, in order to ensure that the charging control circuit 10 and the control system of the electric vehicle have the same negative terminal voltage.

[0045] Continue to refer to Figure 1 and Figure 2 The charging control drive module 130 includes:

[0046] A charging control drive circuit is connected to the signal conditioning module 120. The charging control drive circuit includes: a third transistor Q8, whose base is connected to the fifth resistor R13, whose collector is connected to the negative terminal of the battery, and a sixth resistor R20 is connected between its collector and base; and a third diode D5, whose anode is connected to the base of the third transistor Q8, and whose cathode is connected to the emitter of the third transistor Q8. When the second transistor Q6 is turned on, the power of the charging control drive signal output by the signal conditioning module 120 is relatively low. It needs to be amplified by the third transistor Q8 to drive the subsequent switching devices. The state of the third transistor Q8 is controlled by the voltage at the end of the fifth resistor R13 connected to the base of the third transistor Q8. When both the first transistor Q7 and the second transistor Q6 are turned on, the third transistor Q8 will also be turned on, and after amplifying the power of the charging control drive signal, it will output the amplified charging control drive signal, i.e., the charging control signal. In other words, the charging control signal is the signal output when the third transistor Q8 is turned on.

[0047] The second protection unit, connected to the charging control drive circuit, includes a second clamping diode DZ2 and a second capacitor C3 connected in parallel. The anode of the second clamping diode DZ2 is connected to the collector of the third transistor Q8 and one end of the second capacitor C3, while the cathode of the second clamping diode DZ2 is connected to the emitter of the third transistor Q8 and the other end of the second capacitor C3. Similar to the first protection unit, the second clamping diode DZ2 is used for voltage regulation and, together with the second capacitor C3, prevents voltage changes in the charger signal from causing rapid changes in the state of the third transistor Q8, thus ensuring the stability of the charging control circuit 10.

[0048] Continue to refer to Figure 1 and Figure 2The at least one switching device includes a first field-effect transistor QC1, whose gate is connected to the emitter of the third transistor Q8 via a seventh resistor R14, whose source is connected to the collector of the third transistor Q8, and whose drain is connected to the negative terminal of the charger. When the charging control signal turns on the first field-effect transistor QC1, the negative terminal of the charger 102 is connected to the negative terminal of the battery 152. Specifically, the charger port included in the negative terminal of the charger 102 is connected to the total negative port in the negative terminal of the battery 152; the total negative port is a port connected to at least the negative terminal of the battery.

[0049] Field-effect transistors (FETs) are widely used as switching devices in circuits due to their high switching speed and high voltage withstand capability. Using FETs as switching devices can improve the performance of the charging control circuit 10. In some specific embodiments, the first FET QC1 is an enhancement-mode N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). An enhancement-mode N-channel MOSFET does not conduct at its source and drain when no voltage is applied to the gate, ensuring that no path is formed between the charger's negative terminal and the battery's negative terminal when the charger is not connected, thus ensuring user safety of the charging control circuit 10. The seventh resistor R14 is used to ensure the stability of the gate current of the first FET QC1, improving the reliability of the first FET QC1.

[0050] Since a single switching device can only carry a limited charging current, in some embodiments, to improve the charging power of the charging control circuit 10, the at least one switching device further includes a second field-effect transistor QC2, whose gate is connected to the emitter of the third transistor Q8 by an eighth resistor R18, whose source is connected to the collector of the third transistor Q8, and whose drain is connected to the negative terminal of the charger; when the charging control signal turns on the second field-effect transistor QC2, the negative terminal of the charger is connected to the negative terminal of the battery.

[0051] In some specific implementations, the first field-effect transistor QC1 and the second field-effect transistor QC2 connected in parallel are simultaneously turned on based on the charging control signal, so as to jointly carry the charging current between the negative terminal of the charger and the negative terminal of the battery when charging the battery.

[0052] In some specific implementations, both the first field-effect transistor QC1 and the second field-effect transistor QC2 are enhancement-mode N-channel MOSFETs.

[0053] It should also be noted that, in Figure 2 The thicker line width of the circuit between the charger's negative terminal and the battery's negative terminal indicates that the corresponding connecting line is thicker and can carry the charging current provided by the charger.

[0054] As can be seen, the charging control circuit provided in this application embodiment receives a charger signal through the charger signal input terminal. Since the voltage of the charger signal is relatively high, it needs to be conditioned into a charging control drive signal by passing through a reverse protection module and a signal conditioning module in sequence. The voltage of the charging control drive signal is lower than that of the charger signal. Then, the charging control drive module conditions the charging control drive signal into a charging control signal, and controls the state of at least one switching device in the charging control module through the charging control signal, thereby controlling the on / off state of the charger negative terminal and the battery negative terminal.

[0055] When the charger is connected to the charging control circuit, the charger signal provided by the charger is conditioned into a charging control signal by the reverse protection module, signal conditioning module, and charging control drive module, which connects the negative terminal of the charger and the negative terminal of the battery, thus starting to charge the battery. When the charger is disconnected from the charging control circuit, the path between the negative terminal of the charger and the negative terminal of the battery is broken, so that no voltage is measured between the charger signal input terminal and the negative terminal of the charger, ensuring user safety. Furthermore, since the charging control circuit is composed of analog circuits, that is, all the components in the charging control circuit are analog devices, the switching speed of the charging circuit when the charger switches between connected and disconnected is improved, the battery charging efficiency in the charging control circuit is improved, and user safety is further enhanced.

[0056] This application also provides a charging system, see reference. Figure 3 The charging system includes:

[0057] The charging control circuit 10 as described in the foregoing embodiments.

[0058] The charger 30 includes a charger positive terminal 310, a charger signal terminal 320, and a charger negative terminal 330.

[0059] Battery 40, which includes a positive terminal 410, a wake-up signal terminal 420, and a negative terminal 430.

[0060] The charging port 20 is connected to the charger signal input terminal 101 and the charger signal terminal 320 of the charging control circuit 10, the charger negative terminal 330 and the charger negative terminal connection terminal 102 of the charging control circuit 10, and the charger positive terminal 310 and the battery positive terminal 410.

[0061] The charger 30 is pluggably connected to the charging port 20. The charger 30 is an external charging device that charges the battery 40 inside the electric vehicle via the charging port 20. When the charger 30 is inserted into the charging port 20, i.e., connected to the charging control circuit 10, the negative terminal 102 of the charger and the negative terminal 152 of the battery are connected, and the negative terminal 330 of the charger and the negative terminal 430 of the battery are connected, initiating battery charging. When the charger 30 is disconnected from the charging control circuit 10, the path between the negative terminal 102 of the charger and the negative terminal 430 of the battery is broken, thus preventing the battery voltage from being measured at the charging port 20, ensuring user safety. Furthermore, since the charging control circuit 10 is composed of analog circuits, i.e., all components in the charging control circuit 10 are analog devices, the switching speed of the battery charging circuit is improved, the battery charging efficiency in the charging control circuit is increased, and user safety is further enhanced.

[0062] This application also provides an electric vehicle, including the charging system described in the foregoing embodiments.

[0063] While this application discloses the above information, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of this application; therefore, the scope of protection of this application shall be determined by the scope defined in the claims.

Claims

1. A charging control circuit, characterized in that, The charging control circuit, composed of analog circuitry, includes: The reverse protection module receives the charger signal input from the charger signal input terminal and transmits it unidirectionally. The signal conditioning module receives the charger signal output from the output terminal of the reverse protection module and conditions it into a charging control drive signal, wherein the voltage of the charging control drive signal is less than that of the charger signal. The charging control drive module receives the charging control drive signal output by the signal conditioning module and conditions it into a charging control signal; The charging control module includes at least one switching device, which is connected to the negative terminal of the charger and the negative terminal of the battery, and the state of the switching device is controlled by the charging control signal.

2. The charging control circuit as described in claim 1, characterized in that, The reverse protection module includes: The anode of the first diode is connected to the signal input terminal of the charger. The first resistor has one end connected to the cathode of the first diode; The second diode has its anode connected to the first resistor and its cathode connected to the signal conditioning module.

3. The charging control circuit as described in claim 1, characterized in that, The signal conditioning module includes: The first voltage divider unit is connected to the reverse protection module. The first voltage divider unit includes a second resistor, a third resistor, and a fourth resistor connected in parallel. A signal conditioning circuit is connected to the first voltage divider unit. The signal conditioning circuit includes a first transistor and a second transistor. The base of the first transistor is connected to the fourth resistor, the collector is connected to the third resistor, and the emitter is connected to the base of the second transistor. The base of the second transistor is connected to the second resistor, and the emitter is connected to a fifth resistor. The first protection unit has its two ends connected to the base of the first transistor and the negative terminal of the battery, respectively. The first protection unit includes a first clamping diode and a first capacitor connected in parallel. The cathode of the first clamping diode is connected to the base of the first transistor and one end of the first capacitor. The anode of the first clamping diode is connected to the other end of the first capacitor and the negative terminal of the battery. The charging control drive signal is the signal output when the second transistor is turned on.

4. The charging control circuit as described in claim 3, characterized in that, The charging control drive module includes: A charging control drive circuit is connected to the signal conditioning module. The charging control drive circuit includes: a third transistor, the base of which is connected to the fifth resistor, the collector of which is connected to the negative terminal of the battery, and a sixth resistor connected between the collector and the base; and a third diode, the anode of which is connected to the base of the third transistor, and the cathode of which is connected to the emitter of the third transistor. The second protection unit is connected to the charging control drive circuit. The second protection unit includes a second clamping diode and a second capacitor connected in parallel. The anode of the second clamping diode is connected to the collector of the third transistor and one end of the second capacitor. The cathode of the second clamping diode is connected to the emitter of the third transistor and the other end of the second capacitor. The charging control signal is the signal output when the third transistor is turned on.

5. The charging control circuit as described in claim 4, characterized in that, The at least one switching device includes a first field-effect transistor, whose gate is connected to the emitter of the third transistor by a seventh resistor, whose source is connected to the collector of the third transistor, and whose drain is connected to the negative terminal of the charger. When the charging control signal turns on the first field-effect transistor, the negative terminal of the charger is connected to the negative terminal of the battery.

6. The charging control circuit as described in claim 5, characterized in that, The at least one switching device further includes a second field-effect transistor, whose gate is connected to the emitter of the third transistor by an eighth resistor, whose source is connected to the collector of the third transistor, and whose drain is connected to the negative terminal of the charger. When the charging control signal turns on the second field-effect transistor, the negative terminal of the charger is connected to the negative terminal of the battery.

7. The charging control circuit as described in claim 6, characterized in that, Both the first field-effect transistor and the second field-effect transistor are enhancement-mode N-channel MOSFETs.

8. The charging control circuit as described in claim 2, characterized in that, It also includes a charger signal output terminal; the reverse protection module further includes: a ninth resistor connected to the cathode of the first diode; and a fourth diode, the anode of which is connected to the ninth resistor and the cathode of which is connected to the charger signal output terminal.

9. A charging system, characterized in that, include: The charging control circuit as described in any one of claims 1-8; A charger, comprising a positive terminal, a signal terminal, and a negative terminal; A battery, the battery comprising a positive terminal, a wake-up signal terminal, and a negative terminal; The charging port is connected to the charger signal input terminal and the charger signal terminal of the charging control circuit, the charger negative terminal and the charger negative terminal connection terminal of the charging control circuit, and the charger positive terminal and the battery positive terminal. The charger is pluggably connected to the charging port.

10. An electric vehicle, characterized in that, Includes the charging system as described in claim 9.

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