Temperature detection circuit and charging pile

Abstract

The utility model discloses a temperature detection circuit and a charging pile, and relates to the technical field of charging pile control, the temperature detection circuit comprises a temperature sampling circuit, a temperature rise slope detection circuit, a comparison circuit and a control circuit, the input end of the temperature rise slope detection circuit is electrically connected with the output end of the temperature sampling circuit; the input end of the comparison circuit is electrically connected with the output end of the temperature rise slope detection circuit; the input end of the control circuit is electrically connected with the output end of the comparison circuit, and the control end of the control circuit is electrically connected with the charging switch circuit; and when the control circuit determines that the temperature of the charging gun is in an over-temperature fault state according to the comparison result, a turn-off control signal is output to the charging switch circuit so as to disconnect an electric connection path between the charging module and the charging gun. By detecting the temperature rising slope of the charging gun, measures are taken in time before the temperature reaches the maximum safe temperature threshold value, and therefore potential safety hazards or the risk of equipment damage caused by sudden temperature rising are improved.

Description

Technical Field

[0001] This application relates to the field of charging pile control technology, and in particular to a temperature detection circuit and a charging pile. Background Technology

[0002] With the increasing popularity of electric vehicles, charging stations, as one of their core infrastructures, play a crucial role in providing efficient and safe charging services. However, in actual use, charging guns may overheat due to prolonged high-power operation or elevated ambient temperatures. Overheating not only affects charging efficiency but can also damage the equipment and even pose safety hazards. Traditional temperature detection methods typically rely on setting a fixed temperature threshold. When the detected temperature exceeds this threshold, the charging station system triggers a protection mechanism (such as reducing charging power or stopping charging). However, even if the current sampled temperature has not yet exceeded the threshold, the temperature can rise rapidly in a short period and exceed the threshold in the next moment. The system may not be able to respond in time, leading to equipment damage or even safety hazards. Utility Model Content

[0003] The main purpose of this utility model is to provide a temperature detection circuit and a charging pile, which aims to detect the temperature rise slope of the charging gun and take timely measures before the temperature reaches the maximum safe temperature threshold, thereby improving the risk of safety hazards or equipment damage caused by sudden temperature rise.

[0004] To achieve the above objectives, this utility model proposes a temperature detection circuit for use in a charging pile. The charging pile includes a charging module and a charging gun, and a charging switch circuit is provided between the charging module and the charging gun. The temperature detection circuit includes:

[0005] The temperature sampling circuit is used to sample the temperature of the charging gun and output a temperature sampling signal.

[0006] A temperature rise slope detection circuit is provided, wherein the input terminal of the temperature rise slope detection circuit is electrically connected to the output terminal of the temperature sampling circuit, and the temperature rise slope detection circuit is used to receive the temperature sampling signal, calculate the slope corresponding to the temperature sampling signal, and output the temperature rise slope signal.

[0007] A comparison circuit is provided, wherein the input terminal of the comparison circuit is electrically connected to the output terminal of the temperature rise slope detection circuit. The comparison circuit is used to receive the temperature rise slope signal, and to compare the slope corresponding to the temperature sampling signal with a preset slope value, and output the corresponding comparison result.

[0008] A control circuit, wherein the input terminal of the control circuit is electrically connected to the output terminal of the comparator circuit, and the control terminal of the control circuit is electrically connected to the charging switch circuit;

[0009] The control circuit is used to output a shutdown control signal to the charging switch circuit when it determines that the temperature of the charging gun is in an over-temperature fault state based on the comparison result, so as to disconnect the electrical connection between the charging module and the charging gun.

[0010] In one embodiment, the temperature rise slope detection circuit includes a first capacitor, a first resistor, a second resistor, and an operational amplifier. The first terminal of the first capacitor is electrically connected to the output terminal of the temperature sampling circuit. The second terminal of the first capacitor, the negative input terminal of the operational amplifier, and the first terminal of the second resistor are interconnected. The first terminal of the first resistor is grounded. The second terminal of the first resistor is electrically connected to the positive input terminal of the operational amplifier. The second terminal of the second resistor is electrically connected to the output terminal of the operational amplifier.

[0011] In one embodiment, the comparison circuit includes a third resistor, a fourth resistor, a fifth resistor, and a comparator. The first end of the third resistor is electrically connected to the output terminal of the temperature rise slope detection circuit. The second end of the third resistor, the positive terminal of the comparator, and the first end of the fifth resistor are interconnected. The first end of the fourth resistor is connected to a reference voltage. The second end of the fourth resistor is electrically connected to the negative terminal of the comparator. The second end of the fifth resistor is electrically connected to the output terminal of the comparator.

[0012] In one embodiment, the temperature sampling circuit includes a sixth resistor and a thermistor. The first end of the sixth resistor is connected to the power supply voltage terminal, the second end of the sixth resistor is electrically connected to the first end of the thermistor, the second end of the thermistor is grounded, and the common connection terminal of the sixth resistor and the thermistor is electrically connected to the input terminal of the temperature rise slope detection circuit.

[0013] In one embodiment, the temperature detection circuit further includes:

[0014] A filtering circuit, wherein the input terminal of the filtering circuit is electrically connected to the output terminal of the temperature sampling circuit, and the output terminal of the filtering circuit is electrically connected to the input terminal of the temperature rise slope detection circuit;

[0015] The filtering circuit is used to filter the temperature sampling signal and then output it to the temperature rise slope detection circuit.

[0016] In one embodiment, the filtering circuit includes:

[0017] The seventh resistor, the first end of which is electrically connected to the output terminal of the temperature sampling circuit;

[0018] A filter capacitor, the first end of which is interconnected with the second end of the seventh resistor and the input end of the temperature rise slope detection circuit, and the second end of the filter capacitor is grounded.

[0019] In one embodiment, the temperature detection circuit further includes:

[0020] The display module is electrically connected to the control circuit;

[0021] The control circuit is used to output the comparison result to the display module.

[0022] This utility model proposes a charging pile, which includes the temperature detection circuit described in any of the above claims.

[0023] In one embodiment, the charging pile further includes a charging module, a charging gun, and a charging switch circuit. The charging switch circuit is located between the charging module and the charging gun. The charging module is used to output DC voltage to the charging gun.

[0024] In one embodiment, the charging station further includes:

[0025] The charging control unit has its input terminal electrically connected to the control circuit of the temperature detection circuit, and its control terminal electrically connected to both the charging module and the charging switch circuit.

[0026] The charging control unit is used to receive the over-temperature fault signal output by the control circuit, and control the working state of the charging module and the charging switch circuit according to the over-temperature fault signal.

[0027] This invention proposes a temperature detection circuit, comprising a temperature sampling circuit, a temperature rise slope detection circuit, a comparison circuit, and a control circuit. The temperature sampling circuit samples the temperature of the charging gun and outputs a temperature sampling signal. The input terminal of the temperature rise slope detection circuit is electrically connected to the output terminal of the temperature sampling circuit. The temperature rise slope detection circuit receives the temperature sampling signal, calculates the slope corresponding to the temperature sampling signal, and outputs a temperature rise slope signal. The input terminal of the comparison circuit is electrically connected to the output terminal of the temperature rise slope detection circuit. The comparison circuit compares the slope corresponding to the temperature sampling signal with a preset slope value and outputs the corresponding comparison result. The input terminal of the control circuit is electrically connected to the output terminal of the comparison circuit, and the control terminal of the control circuit is electrically connected to the charging switch circuit. When the control circuit determines that the temperature of the charging gun is in an over-temperature fault state based on the comparison result, it outputs a shutdown control signal to the charging switch circuit to disconnect the electrical connection between the charging module and the charging gun.

[0028] In practical applications, the temperature slope is calculated by the temperature rise slope detection circuit, reflecting the rate of temperature change of the charging gun per unit time, which can provide early warning of potential overheating risks. By analyzing the trend of the slope change, the control circuit and the charging control unit of the charging pile can take preventive measures (such as dynamically adjusting the charging power or enhancing heat dissipation) before the temperature reaches a dangerous level, thereby avoiding safety hazards or equipment damage caused by sudden temperature rises. Compared with protection mechanisms that rely solely on absolute temperature thresholds, temperature rise slope-based detection can respond to temperature changes more quickly. In addition, this application can ensure that the temperature of the charging gun will not rise to the maximum temperature that the charging gun can withstand when the charging pile malfunctions (such as a cooling system failure), effectively protecting the charging gun, charging cables, etc., thereby improving the safety of the charging pile operation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of a module of an embodiment of the temperature detection circuit of this utility model;

[0031] Figure 2 This is a detailed circuit diagram of one embodiment of the temperature detection circuit of this utility model;

[0032] Figure 3 This is a schematic diagram of another embodiment of the temperature detection circuit of this utility model;

[0033] Figure 4 This is a schematic diagram of another embodiment of the temperature detection circuit of this utility model;

[0034] Figure 5 This is a schematic diagram of another embodiment of the temperature detection circuit of this utility model;

[0035] Figure 6 This is a schematic diagram of a module of an embodiment of the charging pile of this utility model.

[0036] Explanation of icon numbers:

[0037] 10. Temperature sampling circuit; 20. Temperature rise slope detection circuit; 30. Comparison circuit; 40. Control circuit; 50. Filtering circuit; 60. Display module; 100. Charging module; 200. Charging gun; 300. Charging switch circuit; 400. Charging control unit.

[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0041] With the increasing popularity of electric vehicles, charging stations, as one of their core infrastructures, play a crucial role in providing efficient and safe charging services. However, in actual use, the charging gun 200 may overheat due to prolonged high-power operation or increased ambient temperature. Overheating of the charging gun 200 not only affects charging efficiency but may also lead to equipment damage or even safety hazards. Traditional temperature detection methods are usually based on setting a fixed temperature threshold. When the current temperature exceeds this threshold, the charging station system triggers a protection mechanism (such as reducing charging power or stopping charging). However, even if the current sampled temperature has not yet exceeded the threshold, the temperature may rise rapidly in a short period of time and exceed the threshold in the next moment, but the system may not be able to respond in time, leading to equipment damage or even safety hazards.

[0042] Furthermore, since the charging gun 200 acts as a bridge between the electric vehicle and the charging station, it can overheat during high-power charging. If the actual temperature of the charging gun 200 exceeds the temperature that its materials can withstand, it will be damaged or even malfunction. Therefore, charging guns 200 with cooling systems are conventionally used. These systems control the circulation of liquid coolant within the charging gun 200 and the cable to dissipate the heat generated when current flows through them, preventing overheating and improving charging efficiency and safety. However, in practical applications, even when the temperature of the charging gun 200 exceeds a safe value and the cooling system is activated, the temperature continues to rise. If the cooling system malfunctions, the temperature of the charging gun 200 will rise sharply during high-current charging, potentially exceeding the material's withstand temperature. Existing solutions still cannot completely protect the charging gun 200.

[0043] Therefore, refer to Figure 1 This utility model proposes a temperature detection circuit for use in a charging pile. The charging pile includes a charging module 100 and a charging gun 200. A charging switch circuit 300 is provided between the charging module 100 and the charging gun 200. The temperature detection circuit includes:

[0044] Temperature sampling circuit 10 is used to sample the temperature of charging gun 200 and output temperature sampling signal;

[0045] Temperature rise slope detection circuit 20, the input terminal of temperature rise slope detection circuit 20 is electrically connected to the output terminal of temperature sampling circuit 10, the temperature rise slope detection circuit 20 is used to receive the temperature sampling signal, calculate the slope corresponding to the temperature sampling signal, and output the temperature rise slope signal;

[0046] The comparison circuit 30 is electrically connected to the output of the temperature rise slope detection circuit 20. The comparison circuit 30 is used to receive the temperature rise slope signal, compare the slope corresponding to the temperature sampling signal with a preset slope value, and output the corresponding comparison result.

[0047] The control circuit 40 has its input terminal electrically connected to the output terminal of the comparator circuit 30, and its control terminal electrically connected to the charging switch circuit 300.

[0048] The control circuit 40 is used to output a shutdown control signal to the charging switch circuit 300 when it is determined from the comparison result that the temperature of the charging gun 200 is in an over-temperature fault state, so as to disconnect the electrical connection between the charging module 100 and the charging gun 200.

[0049] In this embodiment, the temperature sampling circuit 10 can be implemented using temperature sensors such as thermistors, thermocouples, and digital temperature sensors. The temperature sampling circuit 10 can detect the temperature of at least one of the contact area (DC+, DC-) and the pressing area (DC+, DC-), acquiring the temperature of the contact area and / or pressing area inside the charging gun 200 through one or more temperature sensors. Placing multiple temperature sensors at different locations on the charging gun 200 allows for the detection of the temperature at any detection point on the charging gun 200, and the output of a corresponding temperature sampling signal. Optionally, thermistors or other temperature sensors can be installed near heat-generating components inside the charging gun 200, such as near power components, to ensure that the temperature sampling signal output by the temperature sampling circuit 10 accurately reflects the heat generated by the charging gun 200 during charging. The temperature rise slope detection circuit 20 can be implemented using a differentiating circuit, and the comparison circuit 30 can be implemented using a comparator. The control circuit 40 can be implemented using a main controller, such as an MCU, DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), PLC, or SOC (System On Chip).

[0050] It should be noted that the charging module 100 is responsible for converting the AC power from the power grid into DC power, and then charging the electric vehicle's power battery via the charging cable and charging gun 200. The charging switch circuit 300 is the main circuit contactor, used to control the on / off state of the charging circuit. When charging begins, the charging switch circuit 300 closes, establishing the electrical connection between the charging module 100 and the charging gun 200, allowing charging current to flow and charge the power battery; when charging ends or the charging station malfunctions, the charging switch circuit 300 closes, disconnecting the electrical connection between the charging module 100 and the charging gun 200, and cutting off the charging current.

[0051] Specifically, at the start of charging, the charging switch circuit 300 is closed, and the charging cable is connected to the charging socket of the electric vehicle, so that the charging current flows from the charging module 100 to the power battery pack of the electric vehicle. At the same time, the temperature sampling circuit samples the temperature of the charging gun 200 and outputs a temperature sampling signal to the temperature rise slope detection circuit 20. The temperature rise slope detection circuit 20 receives the temperature sampling signal, calculates the slope corresponding to the temperature sampling signal, and outputs a temperature rise slope signal to the comparison circuit 30, so that the comparison circuit 30 compares the slope corresponding to the temperature sampling signal with a preset slope value and outputs the corresponding comparison result. Finally, the control circuit 40 determines whether the temperature of the charging gun 200 is in an over-temperature fault state based on the comparison result. When it is determined that the temperature of the charging gun 200 is in an over-temperature fault state, it outputs a shutdown control signal to the charging switch circuit 300 to control the charging switch circuit 300 to shut down, thereby disconnecting the electrical connection between the charging module 100 and the charging gun 200 and cutting off the charging current.

[0052] In this embodiment, the temperature rise slope of the charging gun 200 is calculated using the following formula:

[0053] dT = (T2 - T1) / dt;

[0054] In the formula, dT is the temperature rise slope of the charging gun at 200°C;

[0055] T1 is the temperature detected at the first time point;

[0056] T2 is the temperature measured at the second time point;

[0057] dt is the time interval between the first time point and the second time point.

[0058] The preset slope k is set in advance by the R&D personnel. In this embodiment, it is set to 5. Assuming that the temperature of the charging gun 200 collected at the first time point 15:50 is 30 degrees Celsius, and the temperature collected at the second time point 16:05 is 130 degrees Celsius, the time interval is 15 minutes, and the temperature difference is 100 degrees Celsius. Therefore, the real-time temperature rise slope is 6.67, which is greater than the preset slope. At this time, the control circuit 40 controls the charging switch circuit 300 to turn off, disconnecting the electrical connection between the charging module 100 and the charging gun 200, and cutting off the charging current. In this way, the power supply is cut off in time, avoiding the possibility that continuing to charge under high temperature conditions may lead to low efficiency or damage to the components in the equipment, or even cause safety hazards.

[0059] Understandably, the control circuit 40 can also directly detect the temperature sampling signal. When it determines that the temperature of the charging gun 200 has reached the first safe temperature threshold, it indicates that although the current temperature does not yet pose an urgent threat, it is approaching a level that may exceed the safe range. The control circuit 40 can then directly control the operating state of the charging module 100 to reduce the charging current of the charging gun 200, thereby reducing the heat generated by the heat source and preventing the temperature from rising further. Optionally, the control circuit 40 can also output a corresponding over-temperature fault signal to the charging control unit 400 of the charging pile, so that the charging control unit 400 controls the output current of the charging module 100 to reduce the charging current of the charging gun 200. When the temperature of the charging gun 200 reaches the second safe temperature threshold, it means that there is a risk of overheating. The control circuit 40 or the charging control unit 400 of the charging pile needs to control the charging switch circuit 300 to shut down, immediately cutting off the charging current and completely stopping the charging process. The first and second safe temperature thresholds are set in advance by the developers. In this way, this dual-layer temperature protection mechanism not only improves the safety of charging but also meets the user's charging needs as much as possible, enhancing the user experience.

[0060] In practical applications, the temperature slope is calculated by the temperature rise slope detection circuit 20, reflecting the rate of temperature change of the charging gun 200 per unit time, which can provide early warning of potential overheating risks. By analyzing the trend of the slope change, the control circuit 40 and the charging control unit 400 of the charging pile can take preventive measures (such as dynamically adjusting the charging power or strengthening heat dissipation) before the temperature reaches a dangerous level, thereby avoiding safety hazards or equipment damage caused by a sudden temperature rise. Compared with protection mechanisms that rely solely on absolute temperature thresholds, temperature rise slope-based detection can respond to temperature changes more quickly. In addition, this application can ensure that the temperature of the charging gun 200 will not rise to the maximum temperature that the charging gun 200 can withstand when the charging pile malfunctions (such as a cooling system failure), effectively protecting the charging gun 200, charging cables, etc., thereby improving the safety of the charging pile operation.

[0061] In another embodiment of this application, reference is made to Figure 2 The temperature rise slope detection circuit 20 includes a first capacitor C1, a first resistor R1, a second resistor R2, and an operational amplifier OP. The first end of the first capacitor C1 is electrically connected to the output end of the temperature sampling circuit 10. The second end of the first capacitor C1, the negative input end of the operational amplifier OP, and the first end of the second resistor R2 are interconnected. The first end of the first resistor R1 is grounded. The second end of the first resistor R1 is electrically connected to the positive input end of the operational amplifier OP. The second end of the second resistor R2 is electrically connected to the output end of the operational amplifier OP.

[0062] In this embodiment, the first capacitor C1 serves to store charge in the circuit. When the input voltage V1 of the temperature rise slope detection circuit 20 suddenly changes, the first capacitor C1 needs to be charged or discharged to adapt to the new voltage state. During this process, the voltage across the first capacitor C1 does not change immediately, but gradually. At the virtual breakpoint of the ideal operational amplifier, the current flowing through resistor R2 is equal to the current flowing through the first capacitor C1. That is, i = C1 * dV1 / dt, where i is the current flowing through the first capacitor, and dV1 / dt is the rate of change of the input voltage V1. Since the current flows through the second resistor R2, the voltage across the second resistor is V2 = -iR2 = -C1R2 * dV1 / dt. Therefore, the output voltage V2 of the temperature rise slope detection circuit 20 is proportional to the rate of change of the input voltage V1, but in the opposite direction. Therefore, the change in the output voltage V2 of the temperature rise slope detection circuit 20 can be used to characterize the slope and direction of the input voltage change, thereby determining the temperature rise slope of the charging gun 200, referred to as the temperature rise slope, and taking corresponding control measures accordingly.

[0063] Optionally, the temperature sampling circuit 10 includes a sixth resistor and a thermistor. The first end of the sixth resistor is connected to the power supply voltage terminal, the second end of the sixth resistor is electrically connected to the first end of the thermistor, the second end of the thermistor is grounded, and the common connection terminal of the sixth resistor and the thermistor is electrically connected to the input terminal of the temperature rise slope detection circuit 20.

[0064] In this embodiment, the power supply voltage terminal VCC provides a stable power supply voltage, and the resistance of the thermistor RT changes with temperature. It can be understood that in an NTC thermistor, the resistance decreases as temperature increases; while in a PTC thermistor, the resistance increases as temperature increases. In this embodiment, the thermistor and the sixth resistor R6 form a voltage divider circuit. At the common connection point between the sixth resistor R6 and the thermistor RT, a voltage Va can be obtained. This voltage is the result of distributing the power supply voltage according to the ratio of the two resistors R6 and RT. When the temperature of the charging gun 200 changes, the resistance of RT changes, thereby causing a change in the output voltage Va of the temperature sampling circuit 10.

[0065] In conjunction with the above embodiments, when the output voltage Va (temperature sampling signal) of the temperature sampling circuit 10 is output to the input terminal of the temperature rise slope detection circuit 20, Va is V1. The change in the output voltage V2 of the temperature rise slope detection circuit 20 represents the slope (temperature change rate) and direction of the input voltage change, and thus reflects the magnitude of the temperature rise slope of the charging gun 200.

[0066] Optionally, the comparison circuit 30 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a comparator CMP. The first end of the third resistor R3 is electrically connected to the output terminal of the temperature rise slope detection circuit 20. The second end of the third resistor R3, the positive terminal of the comparator, and the first end of the fifth resistor R5 are interconnected. The first end of the fourth resistor R4 is connected to a reference voltage Vref. The second end of the fourth resistor R4 is electrically connected to the negative terminal of the comparator. The second end of the fifth resistor R5 is electrically connected to the output terminal of the comparator.

[0067] In this embodiment, the third resistor R3 and the fourth resistor R4 are current-limiting resistors, and the fifth resistor is a feedback resistor, limiting the current flowing through the input terminal of the comparator, thereby protecting the comparator from damage to a certain extent. The positive terminal of the comparator CMP is connected to the output voltage V2 of the temperature rise slope detection circuit 20, and the negative terminal of the comparator CMP is connected to a fixed voltage reference value Vref, which reflects a preset slope. The operational amplifier acts as the comparator CMP, and its output voltage Vo depends on the magnitude relationship between the voltages at the positive and negative terminals. That is, when the voltage V2 at the positive terminal > Vref, it indicates that the slope of the input voltage V1 exceeds the preset reference value Vref, and the comparator outputs a high-level signal. Conversely, the comparator outputs a low-level signal. When the control circuit 40 determines that Uo is a high-level signal, it determines that the temperature of the charging gun 200 is in an over-temperature fault state, and outputs a shutdown control signal to the charging switch circuit 300 to disconnect the electrical connection between the charging module 100 and the charging gun 200. When the control circuit 40 determines that Uo is a low-level signal, it indicates that the charging gun 200 is in normal working condition and no action is required.

[0068] By combining a multi-layered safety mechanism consisting of a temperature sampling circuit 10, a temperature rise slope detection circuit 20, a comparison circuit 30, and a control circuit 40, when the temperature rise slope of the charging gun 200 exceeds a preset slope, the comparator CMP outputs a high-level signal, triggering the control circuit 40 to cut off the charging current, thereby avoiding safety hazards caused by high temperatures. This mechanism can accurately predict and promptly handle potential overheating of the charging gun 200, eliminating user concerns about sudden interruptions or prolonged waiting times due to overheating. This helps improve user trust and satisfaction with the charging station service.

[0069] It should be noted that the temperature sampling circuit 10 may be affected by external electromagnetic interference (EMI), power supply fluctuations, or the nonlinear characteristics of the thermistor itself, resulting in high-frequency noise mixed in the output signal. This noise may be mistaken by the subsequent temperature rise slope detection circuit 20 as a real temperature change, leading to misjudgment. Consequently, the control circuit 40 may erroneously trigger the charging switch circuit 300 to shut down, cutting off the charging current when the charging gun 200 is not in an over-temperature fault state, thus degrading the user experience.

[0070] Therefore, in one embodiment of this application, reference is made to Figure 3 The temperature detection circuit further includes:

[0071] A filter circuit 50 is provided, the input terminal of which is electrically connected to the output terminal of the temperature sampling circuit 10, and the output terminal of the filter circuit 50 is electrically connected to the input terminal of the temperature rise slope detection circuit 20.

[0072] The filtering circuit 50 is used to filter the temperature sampling signal and output it to the temperature rise slope detection circuit 20.

[0073] In this embodiment, the filter circuit 50 can be implemented by using at least one of resistors, capacitors, and inductors.

[0074] In this embodiment, reference Figure 2 The filter circuit 50 includes:

[0075] The seventh resistor R7, the first end of which is electrically connected to the output terminal of the temperature sampling circuit 10;

[0076] The first terminal of the filter capacitor C2 is interconnected with the second terminal of the seventh resistor R7 and the input terminal of the temperature rise slope detection circuit 20, and the second terminal of the filter capacitor C2 is grounded.

[0077] In this embodiment, the filter circuit 50 is a typical RC low-pass filter, which allows low-frequency signals to pass through while suppressing high-frequency noise. After the temperature sampling signal Va passes through the seventh resistor R7 and the filter capacitor C2, the high-frequency noise is attenuated, and the output signal becomes smoother and more stable. The filtered temperature sampling signal V1 is output to the output terminal of the temperature rise slope detection circuit 20 to calculate the slope, and outputs the temperature rise slope signal V2 to the comparison circuit 30, so that the comparison circuit 30 compares it with the reference voltage Vref and outputs the corresponding comparison result Uo to the control circuit 40.

[0078] After removing high-frequency noise through the filter circuit 50, the temperature rise slope detection circuit 20 can perform accurate calculations based on a cleaner signal, thereby improving the reliability of temperature rise slope detection and preventing the temperature rise slope detection circuit 20 from outputting abnormal signals, which would trigger the actions of the comparison circuit 30 and the control circuit 40 (such as reducing charging power or cutting off charging current). This ensures that the system only takes protective measures when there is a real risk of overheating in the charging gun 200, further enhancing the user experience.

[0079] In one embodiment, reference Figure 4 The temperature detection circuit further includes:

[0080] Display module 60, which is electrically connected to control circuit 40;

[0081] The control circuit 40 is used to output the comparison result to the display module 60.

[0082] In this embodiment, the display module 60 can be implemented using a driver module and a display screen. The display screen can be an LCD screen or an LED screen, and driver modules are set accordingly for different types of display screens.

[0083] Specifically, the display screen can be installed on the charging pile itself. The control circuit 40 can determine whether protective measures (such as reducing charging power or cutting off charging current) are needed based on the comparison results, and simultaneously output the comparison results directly to the drive module. This allows the drive module to drive the display module 60 to display temperature information and fault alerts. Users can view the temperature changes of the charging gun 200 in real time through the display screen. Optionally, the control circuit 40 can also output a fault alert signal to the drive module when it determines that the charging gun 200 is in an over-temperature fault state, causing the drive module to drive the display screen. In this way, the temperature detection circuit can provide early warnings through the display screen. For example, if the temperature rise slope exceeds a preset slope but has not yet reached the emergency cut-off condition, the main circuit contactor (charging switch circuit 300) will only be cut off after a preset delay when an over-temperature fault is determined. At this time, a warning message can be displayed on the screen to remind the user to pay attention to the current temperature trend. The user can choose to intervene manually, such as adjusting the charging power or pausing charging to prevent the temperature from continuing to rise. Assume a charging pile is equipped with an LCD display screen and a corresponding drive module. The control circuit 40 acquires temperature data once per second from the temperature sampling circuit 10 or the temperature rise slope detection circuit 20, converts it into an easily understandable format (such as degrees Celsius), and sends it to the display module 60. If the temperature rise slope exceeds the set safety range, i.e., exceeds the preset slope, a yellow warning message will be displayed on the screen: "Caution! Temperature is rising rapidly." If the temperature reaches the emergency cut-off threshold (such as the second safe temperature threshold), the screen will switch to a red warning page, displaying "Over-temperature fault, please stop charging!" At the same time, the control circuit 40 will automatically cut off the charging circuit. In this way, to a certain extent, the charging gun 200, charging cable, power battery, etc. are protected from over-temperature damage, improving charging safety and user experience.

[0084] It should be noted that, in order to save on circuit design costs and reduce the footprint and size of the temperature detection circuit, the display module 60 can be integrated with the display module 60 of the charging pile. This not only allows for the sharing of hardware resources (such as power supply and processor), but also simplifies the user interface design and provides a unified operating experience.

[0085] This application proposes a charging pile, which includes the temperature detection circuit described above.

[0086] refer to Figure 5 and Figure 6 The charging pile also includes a charging module 100, a charging gun 200, and a charging switch circuit 300. The charging switch circuit 300 is located between the charging module 100 and the charging gun 200. The charging module 100 is used to output DC voltage to the charging gun 200.

[0087] The charging station also includes:

[0088] A charging control unit 400, the input terminal of which is electrically connected to the control circuit 40 of the temperature detection circuit, and the control terminal of which is electrically connected to the charging module 100 and the charging switch circuit 300 respectively.

[0089] The charging control unit 400 is used to receive the over-temperature fault signal output by the control circuit 40, and control the working state of the charging module 100 and the charging switch circuit 300 according to the over-temperature fault signal.

[0090] In this embodiment, the charging control unit 400 can be implemented using the aforementioned main controller. The charging switch circuit 300 is the main circuit contactor C1 / C2. The control circuit 40 can be an over-temperature protection unit (TPU).

[0091] It should be noted that after the temperature sampling circuit 10 converts the temperature signal (including the internal temperature information of the charging gun 200) into a voltage signal, a portion is output to the amplification and isolation circuit for amplification and isolation. Then, it is converted into a digital signal by the AD conversion chip and enters the controller CPU of the charging pile. The collected internal temperature information of the charging gun 200 is transmitted to the charging control unit 400 (CCU) via a communication interface (RS485, CAN, or other communication interfaces). The charging control unit 400 then performs charging current limiting or protection according to a pre-set control strategy. For example, when the CPU determines that the temperature of the charging gun 200 exceeds a first safe temperature threshold, it executes a current limiting program or a shutdown program. This protection is the mainstream temperature detection and over-temperature protection mode for current charging equipment. In addition, the voltage signal output by the temperature sampling circuit 10 can be filtered by the filter circuit 50 and then output to another comparator U2 (not shown) to form a hardware over-temperature protection circuit. For example, the input terminal of the comparator U2 is connected to the filtered voltage signal, and the reference terminal of the comparator U2 is connected to a preset protection value (such as the first safe temperature threshold). When the value connected to the input terminal of the comparator U2 is greater than the value at the reference terminal of the comparator, the comparator outputs an over-temperature fault signal to the charging control unit 400 (CCU). That is, after detecting that the temperature of any detection point inside the charging gun 200 exceeds the set protection value, the over-temperature fault signal will be immediately fed back to the CCU, and the CCU will start the fault shutdown and, after a delay, disconnect the main circuit contactor C1 / C2. Meanwhile, the voltage signal output by the temperature sampling circuit 10 can be filtered by the filter circuit 50 and then output to the temperature rise slope detection circuit 20 to calculate the temperature rise slope and output the temperature rise slope signal to the comparison circuit 30. When the control circuit 40 determines that the temperature rise slope of any detection point of the charging gun 200 exceeds the preset slope based on the comparison result output by the comparison circuit 30, it directly cuts off the main circuit contactor C1 / C2. At the same time, the over-temperature protection unit TPU outputs the corresponding over-temperature fault signal to the charging control unit 400 so that the charging control unit 400 can start the over-temperature protection function and control the charging module 100 to stop working.

[0092] It is worth noting that since the charging pile of this application includes the temperature detection circuit described above, the embodiments of the charging pile of this application include all the technical solutions of all embodiments of the temperature detection circuit described above, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0093] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of the present utility model.

Claims

1. A temperature detection circuit applied to a charging pile, the charging pile comprising a charging module and a charging gun, wherein a charging switch circuit is provided between the charging module and the charging gun, characterized in that, The temperature detection circuit includes: The temperature sampling circuit is used to sample the temperature of the charging gun and output a temperature sampling signal. A temperature rise slope detection circuit is provided, wherein the input terminal of the temperature rise slope detection circuit is electrically connected to the output terminal of the temperature sampling circuit, and the temperature rise slope detection circuit is used to receive the temperature sampling signal, calculate the slope corresponding to the temperature sampling signal, and output the temperature rise slope signal. A comparison circuit is provided, wherein the input terminal of the comparison circuit is electrically connected to the output terminal of the temperature rise slope detection circuit. The comparison circuit is used to receive the temperature rise slope signal, and to compare the slope corresponding to the temperature sampling signal with a preset slope value, and output the corresponding comparison result. A control circuit, wherein the input terminal of the control circuit is electrically connected to the output terminal of the comparator circuit, and the control terminal of the control circuit is electrically connected to the charging switch circuit; The control circuit is used to output a shutdown control signal to the charging switch circuit when it determines that the temperature of the charging gun is in an over-temperature fault state based on the comparison result, so as to disconnect the electrical connection between the charging module and the charging gun.

2. The temperature detection circuit as described in claim 1, characterized in that, The temperature rise slope detection circuit includes a first capacitor, a first resistor, a second resistor, and an operational amplifier. The first terminal of the first capacitor is electrically connected to the output terminal of the temperature sampling circuit. The second terminal of the first capacitor, the negative input terminal of the operational amplifier, and the first terminal of the second resistor are interconnected. The first terminal of the first resistor is grounded. The second terminal of the first resistor is electrically connected to the positive input terminal of the operational amplifier. The second terminal of the second resistor is electrically connected to the output terminal of the operational amplifier.

3. The temperature detection circuit as described in claim 1, characterized in that, The comparison circuit includes a third resistor, a fourth resistor, a fifth resistor, and a comparator. The first end of the third resistor is electrically connected to the output end of the temperature rise slope detection circuit. The second end of the third resistor, the positive terminal of the comparator, and the first end of the fifth resistor are interconnected. The first end of the fourth resistor is connected to a reference voltage. The second end of the fourth resistor is electrically connected to the negative terminal of the comparator. The second end of the fifth resistor is electrically connected to the output end of the comparator.

4. The temperature detection circuit as described in claim 1, characterized in that, The temperature sampling circuit includes a sixth resistor and a thermistor. The first end of the sixth resistor is connected to the power supply voltage terminal, the second end of the sixth resistor is electrically connected to the first end of the thermistor, the second end of the thermistor is grounded, and the common connection terminal of the sixth resistor and the thermistor is electrically connected to the input terminal of the temperature rise slope detection circuit.

5. The temperature detection circuit as described in any one of claims 1-4, characterized in that, The temperature detection circuit also includes: A filtering circuit, wherein the input terminal of the filtering circuit is electrically connected to the output terminal of the temperature sampling circuit, and the output terminal of the filtering circuit is electrically connected to the input terminal of the temperature rise slope detection circuit; The filtering circuit is used to filter the temperature sampling signal and then output it to the temperature rise slope detection circuit.

6. The temperature detection circuit as described in claim 5, characterized in that, The filtering circuit includes: The seventh resistor, the first end of which is electrically connected to the output terminal of the temperature sampling circuit; A filter capacitor, the first end of which is interconnected with the second end of the seventh resistor and the input end of the temperature rise slope detection circuit, and the second end of the filter capacitor is grounded.

7. The temperature detection circuit as described in any one of claims 1-4, characterized in that, The temperature detection circuit also includes: The display module is electrically connected to the control circuit; The control circuit is used to output the comparison result to the display module.

8. A charging pile, characterized in that, The charging pile includes a temperature detection circuit as described in any one of claims 1 to 7.

9. The charging pile as described in claim 8, characterized in that, The charging pile also includes a charging module, a charging gun, and a charging switch circuit. The charging switch circuit is located between the charging module and the charging gun. The charging module is used to output DC voltage to the charging gun.

10. The charging pile as described in claim 9, characterized in that, The charging station also includes: The charging control unit has its input terminal electrically connected to the control circuit of the temperature detection circuit, and its control terminal electrically connected to both the charging module and the charging switch circuit. The charging control unit is used to receive the over-temperature fault signal output by the control circuit, and control the working state of the charging module and the charging switch circuit according to the over-temperature fault signal.

Images