Cp signal detection module and charging outlet

Abstract

The application discloses a CP signal detection module and a charging socket. The CP signal detection module comprises a surge protection circuit and a function detection circuit. The surge protection circuit comprises a signal receiving end and a signal output end. The signal receiving end receives an initial detection signal. The surge protection circuit is configured to perform a protection operation on the initial detection signal and output a target detection signal at the signal output end. The initial detection signal comprises a CP signal input by a charging pile or a test signal. The function detection circuit determines a circuit state of the function detection circuit according to the target detection signal. The CP signal detection module can improve the reliability and stability of CP signal detection.

Description

Technical Field

[0001] This application relates to the field of charging detection technology, and in particular to a CP signal detection module and a charging socket. Background Technology

[0002] Control Pilot (CP) signals are transmitted between electric vehicles and charging stations to determine the charging connection status, control the charging process, and provide electric shock protection. CP signal detection allows us to determine the connection status and fault status of the charging device by analyzing changes in its level. In abnormal situations such as CP signal interruption, emergency stop operations (e.g., insertion / removal detection, insulation fault) are triggered to achieve safety protection. Therefore, ensuring the reliability and stability of the CP signal is a key technical challenge currently being researched and addressed in the industry. Utility Model Content

[0003] This application provides a CP signal detection module and a charging socket, which can improve the reliability and stability of CP signal detection, thereby at least partially solving the above-mentioned technical problems.

[0004] To achieve the above objectives, according to a first aspect of this application, a CP signal detection module is provided, comprising: a surge protection circuit including a signal receiving end and a signal output end, wherein the signal receiving end receives an initial detection signal, and the surge protection circuit is configured to perform a protection operation on the initial detection signal and then output a target detection signal at the signal output end; wherein the initial detection signal includes a CP signal or a test signal input from a charging pile; and a function detection circuit connected to the surge protection circuit, wherein the function detection circuit is configured to determine the circuit state of the function detection circuit based on the detection signal and the sampling signal.

[0005] Optionally, the function detection circuit includes: a first sampling circuit and a second sampling circuit, the first sampling circuit and the second sampling circuit being respectively connected to the surge protection circuit, the first sampling circuit being configured to sample the target detection signal to obtain a first sampling signal, and the second sampling circuit being configured to sample the target detection signal to obtain a second sampling signal; the function detection circuit determines the circuit state of the function detection circuit based on the first sampling signal and the second sampling signal.

[0006] Optionally, the first sampling signal includes an amplitude detection signal and a duty cycle detection signal, and the first sampling circuit includes: a voltage amplitude detection branch, including a first signal input terminal and a first signal output terminal, wherein the voltage amplitude detection branch is configured to obtain an amplitude detection signal at the first signal output terminal based on the target detection signal input at the first signal input terminal; and a duty cycle detection branch, including a second signal input terminal and a second signal output terminal, wherein the duty cycle detection branch is configured to input the target detection signal at the second signal input terminal and obtain a duty cycle detection signal at the second signal output terminal.

[0007] Optionally, the voltage amplitude detection branch includes: an isolation circuit connected to the signal receiving end of the surge protection circuit, the isolation circuit being configured to determine the input state of the signal receiving end and the initial detection signal based on the circuit state of the sampling circuit; a first conditioning circuit connected to the signal output end of the surge protection circuit, the first conditioning circuit being configured to condition the target detection signal to obtain a conditioned signal; a buffer circuit connected to the first conditioning circuit, the buffer circuit being configured to buffer the conditioned signal to obtain a buffered signal; and a first filtering circuit connected to the buffer circuit, the first filtering circuit being configured to filter the buffered signal to obtain a first filtered signal, and to obtain the amplitude detection signal at the first signal output end based on the first filtered signal.

[0008] Optionally, the isolation circuit includes a first relay, the first conditioning circuit includes a first resistor and a second resistor, the buffer circuit includes a third resistor and a follower circuit, and the first filter circuit includes a fourth resistor and a first capacitor; wherein, the first relay is connected to the signal receiving terminal of the surge protection circuit, the first end of the first resistor is connected to the signal output terminal of the surge protection circuit, the second end of the first resistor is connected to the first end of the second resistor and the first end of the third resistor respectively, the second end of the third resistor is connected to the follower circuit, the second end of the follower circuit is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first end of the first capacitor and the first signal output terminal respectively, and the second end of the second resistor and the second end of the first capacitor are grounded.

[0009] Optionally, the duty cycle detection branch includes: a conversion circuit configured to convert the target detection signal output by the surge protection circuit to obtain a converted signal; a discharge circuit connected to both the surge protection circuit and the conversion circuit, configured to perform a discharge operation; and a second filter circuit connected to the conversion circuit, configured to filter the converted signal to obtain a second filter signal, and to obtain the duty cycle detection signal at the second signal output terminal based on the second filter signal.

[0010] Optionally, the conversion circuit includes a semiconductor component, the discharge circuit includes a fifth resistor and a first diode, and the second filter circuit includes a sixth resistor and a second capacitor; wherein, the first end of the fifth resistor is connected to the signal output terminal of the surge protection circuit and the negative terminal of the first diode, the second end of the fifth resistor is connected to the positive terminal of the first diode and the first end of the semiconductor component, the second end of the semiconductor component is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the second capacitor and the second signal output terminal, and the second end of the second capacitor and the third end of the semiconductor component are grounded.

[0011] Optionally, the second sampling circuit includes: an isolation circuit connected to the signal output terminal of the surge protection circuit, the isolation circuit being configured to isolate the target detection signal; a second conditioning circuit connected to the isolation circuit, the second conditioning circuit being configured to perform level conversion on the target detection signal to obtain a converted signal; and a third filtering circuit connected to the second conditioning circuit, the third filtering circuit being configured to filter the converted signal and obtain the second sampling signal based on the filtered converted signal.

[0012] Optionally, the isolation circuit includes a seventh resistor and an optocoupler, the second conditioning circuit includes an eighth resistor, a ninth resistor, and a first switching transistor, and the third filtering circuit includes a tenth resistor and a third capacitor; wherein, the first terminal of the seventh resistor is configured to be connected to the signal output terminal of the surge protection circuit, the second terminal of the seventh resistor is connected to the first terminal of the optocoupler, the second terminal of the optocoupler is connected to the first terminals of the eighth resistor and the ninth resistor respectively, the second terminal of the eighth resistor is connected to the first terminal of the first switching transistor and the power signal respectively, the control terminal of the first switching transistor is connected to the second terminal of the ninth resistor, the second terminal of the first switching transistor is connected to the first terminal of the tenth resistor, the second terminal of the tenth resistor is connected to the first terminal of the third capacitor respectively, and the second terminal of the third capacitor is grounded.

[0013] Optionally, the CP signal detection module further includes a signal injection circuit connected to the surge protection circuit. The signal injection circuit is configured to input the test signal to the surge protection circuit when the CP signal detection module is not connected to the charging pile, so that the function detection circuit performs function detection based on the test signal.

[0014] Optionally, the signal injection circuit includes: a second relay, a second diode, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a first switch, and a signal generator. The first terminal of the second relay is connected to the signal receiving terminal of the surge protection circuit. The second terminal of the second relay is connected to the negative terminal of the second diode. The positive terminal of the second diode is connected to the first terminal of the eleventh resistor, the first terminal of the fourth capacitor, and the first terminal of the signal generator. The second terminal of the signal generator is grounded through the twelfth resistor. The third terminal of the signal generator is connected to the first terminal of the fifth capacitor and the first terminal of the first switch. The fourth terminal of the signal generator is connected to the second terminal of the first switch through the thirteenth resistor. The second terminals of the fourth capacitor, the twelfth resistor, and the fifth capacitor are grounded.

[0015] Optionally, the surge protection circuit includes: a gas discharge tube, a thermistor, and a transient voltage suppressor connected in sequence; wherein, the gas discharge tube is configured to discharge a first surge signal, the energy of which is greater than an energy threshold; the thermistor is configured to limit current under overcurrent conditions; and the transient voltage suppressor is configured to perform voltage clamping under surge conditions.

[0016] According to a second aspect of this application, a charging socket is provided, which is installed in a vehicle. The charging socket includes a socket body, a signal processing module, and a CP signal detection module as described above. The socket body is configured to connect to a charging pile via a charging gun. The CP signal detection module is installed within a cavity of the socket body and is configured to determine state data of the CP signal detection module based on a target detection signal. The signal processing module is connected to the CP signal detection module and is configured to obtain charging control data based on the state data.

[0017] In summary, the CP signal detection module provided in this application includes a surge protection circuit and a functional detection circuit. The surge protection circuit includes a signal receiving end and a signal output end. The signal receiving end receives an initial detection signal, and the surge protection circuit is configured to perform a protection operation on the initial detection signal and then output a target detection signal at the signal output end. The initial detection signal includes either the CP signal input from the charging pile or a test signal. The functional detection circuit determines the circuit state of the functional detection circuit based on the target detection signal. The CP signal detection module in this application can perform surge protection through the surge protection circuit, improving the stability and reliability of the CP signal. Furthermore, the detection signal of the input signal detection module in this application includes both the CP signal and the test signal. That is, even when the circuit in this application is not powered on and connected to the CP signal, it can still perform self-testing based on the test signal, improving detection efficiency. It can also perform fault diagnosis in advance based on the detection of the test signal, improving the reliability and stability of the CP signal detection. Attached Figure Description

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

[0019] Figure 1 This is a schematic diagram of the structure of a CP signal detection module provided in an embodiment of this application; Figure 2 This is a schematic diagram of another CP signal detection module provided in an embodiment of this application; Figure 3 A circuit diagram of a first sampling circuit provided in an embodiment of this application; Figure 4 A circuit diagram of a second sampling circuit and a signal injection circuit provided in an embodiment of this application; Figure 5 A circuit diagram of a surge protection circuit provided in an embodiment of this application; Figure 6 A schematic diagram illustrating the workflow of a CP signal detection module provided in an embodiment of this application; Figure 7 This is a connection diagram of a CP signal detection module provided in an embodiment of this application.

[0020] Explanation of icon numbers: 100. Surge protection circuit; 200. Function detection circuit; 210. First sampling circuit; 211. Isolation circuit; 212. First conditioning circuit; 213. Buffer circuit; 214. First filter circuit; 215. Conversion circuit; 216. Discharge circuit; 217. Second filter circuit; 220. Second sampling circuit; 221. Isolation circuit; 222. Second conditioning circuit; 223. Third filter circuit; 300. Signal injection circuit.

[0021] The realization of the objectives, functional features and advantages of the embodiments of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] 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 a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] Furthermore, descriptions involving "first," "second," etc., in the embodiments of this application 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, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If 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 in this application.

[0024] The Control Pilot (CP) signal is generated by the Electric Vehicle Supply Equipment (EVSE) and transmits information such as the available current and voltage of the charging station through Pulse Width Modulation (PWM) signals. In practical applications, abnormal operating conditions may occur. For example, an electric arc may be generated when the charging gun is plugged in or unplugged, causing a brief short circuit between the CP signal pin and the power lines (phase line L / neutral line N / ground line PE); plugging or unplugging the charging gun without completely disconnecting the power supply may cause arcing and burning of the CP signal pin; abnormal fluctuations in the power grid, charging station relay switching, and other high-voltage transient surge signals may also be transmitted to the CP signal line.

[0025] In view of this, this application proposes a CP signal detection device to improve the reliability and stability of CP signal detection and enhance the safety of charging control.

[0026] Please see Figure 1 , Figure 1 This is a schematic diagram of a CP signal detection module provided in an embodiment of this application. Figure 1 As shown, the CP signal detection module includes a surge protection circuit 100 and a functional detection circuit 200 connected to the surge protection circuit 100. The surge protection circuit 100 includes a signal receiving end and a signal output end. The signal receiving end receives an initial detection signal, and after performing protection operations on the initial detection signal, the surge protection circuit outputs a target detection signal at the signal output end. The functional detection circuit 200 determines the circuit state of the functional detection circuit based on the detection signal; wherein, the initial detection signal includes the CP signal or test signal input from the charging pile.

[0027] In this embodiment, the CP signal is detected to determine the fault status data of the signal detection module based on the detection result, and then the charging control can be performed based on the fault status data.

[0028] like Figure 1 As shown, in this embodiment of the application, when the CP signal detection module is working, the initial detection signal is first protected against surges by the surge protection circuit 100. This surge protection operation improves the circuit's anti-interference capability and reliability. Simultaneously, the initial detection signal in this embodiment includes the CP signal input from the charging pile or a test signal. It can perform self-testing based on the test signal even without being connected to the charging pile and powered on, improving detection efficiency. Furthermore, it can perform fault diagnosis in advance based on the detection of the test signal, improving the reliability and stability of the CP signal detection.

[0029] The functional detection circuit 200 of this application embodiment determines the circuit state of the functional detection circuit 200 based on the target detection signal, and then performs charging operation control based on the circuit state to improve the stability and reliability of the CP signal.

[0030] In some embodiments, please refer to Figure 2 , Figure 2 This is a schematic diagram of another CP signal detection module provided in an embodiment of this application. Figure 2 As shown, the sampling signal includes a first sampling signal and a second sampling signal. The function detection circuit 200 includes a first sampling circuit 210 and a second sampling circuit 220. The first sampling circuit 210 and the second sampling circuit 220 are respectively connected to the surge protection circuit 100. The first sampling circuit 210 is configured to sample the target detection signal to obtain the first sampling signal; the second sampling circuit 220 is configured to sample the target detection signal to obtain the second sampling signal.

[0031] In this embodiment, the functional detection circuit 200 includes a first sampling circuit 210 and a second sampling circuit 220. One of the first sampling circuit 210 and the other of the second sampling circuit 220 is a primary sampling circuit, and the other is a redundant sampling circuit. By setting up redundant sampling circuits, this embodiment can provide reliable redundant detection functionality. Even if one sampling circuit fails, the other sampling circuit can still operate normally, improving the reliability and stability of the detection.

[0032] In some embodiments, please refer to Figure 3 , Figure 3 This is a circuit diagram of a first sampling circuit provided in an embodiment of this application. Figure 3 As shown, the first sampling signal includes an amplitude detection signal and a duty cycle detection signal. The first sampling circuit 210 includes a voltage amplitude detection branch and a duty cycle detection branch. The voltage amplitude detection branch includes a first signal input terminal and a first signal output terminal. The voltage amplitude detection branch obtains the amplitude detection signal at the first signal output terminal based on the target detection signal input at the first signal input terminal. The duty cycle detection branch includes a second signal input terminal and a second signal output terminal. The duty cycle detection branch obtains the duty cycle detection signal at the second signal output terminal based on the target detection signal input at the second signal input terminal.

[0033] The first sampling circuit 210 obtains a first sampling signal based on the signals from the voltage amplitude detection branch and the duty cycle detection branch. Compared with the unidirectional detection method of related technologies, the embodiments of this application simultaneously detect the voltage amplitude signal and the duty cycle signal, which can realize dual verification of the charging gun connection reliability and effectively avoid the risk of damage to subsequent circuits due to misjudgment by the charger or poor contact.

[0034] In some embodiments, please continue reading Figure 3 The voltage amplitude detection branch includes: an isolation circuit 211, a first conditioning circuit 212, a buffer circuit 213, and a first filter circuit 214. The isolation circuit 211 is connected to the signal receiving end of the surge protection circuit 100. The isolation circuit 211 determines the input state of the signal receiving end and the initial detection signal based on the circuit state of the sampling circuit. The first conditioning circuit 212 is connected to the signal output end of the surge protection circuit 100. The first conditioning circuit 212 conditions the target detection signal to obtain a conditioned signal. The buffer circuit 213 is connected to the first conditioning circuit 212. The buffer circuit 213 buffers the conditioned signal to obtain a buffered signal. The first filter circuit 214 is connected to the buffer circuit 213. The first filter circuit 214 filters the buffered signal to obtain a first filtered signal, and the amplitude detection signal is obtained at the first signal output end based on the first filtered signal.

[0035] In some embodiments, the isolation circuit 211 includes a first relay, the first conditioning circuit 212 includes a first resistor and a second resistor, the buffer circuit 213 includes a third resistor and a follower circuit, and the first filter circuit 214 includes a fourth resistor and a first capacitor; the first relay is connected to the signal receiving terminal of the surge protection circuit 100, the first end of the first resistor is connected to the signal output terminal of the surge protection circuit 100, the second end of the first resistor is connected to the first end of the second resistor and the first end of the third resistor respectively, the second end of the third resistor is connected to the follower circuit, the second end of the follower circuit is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first end of the first capacitor and the first signal output terminal respectively, and the second end of the second resistor and the second end of the first capacitor are grounded.

[0036] like Figure 3 As shown, when the voltage amplitude detection branch is working, it is safely isolated by the isolation circuit 211, the signal is converted by the first conditioning circuit 212, the stable transmission of the signal is ensured by the buffer circuit 213, and the interference signal is filtered out by the first filtering circuit 214 to improve the detection accuracy of the amplitude detection signal.

[0037] The isolation circuit 211 includes a first relay K1, which is connected to the surge protection circuit 100 and serves as a signal path switch for the charging pile CP signal. The first relay K1 is a normally closed relay, controlled by the MCU_CP1_in signal. The first relay K1 is in the open state by default and only closes when the main sampling circuit malfunctions, so as to achieve safe isolation of the main sampling circuit.

[0038] The first conditioning circuit 212 includes a first resistor R1 and a second resistor R2 as voltage divider resistors. The first resistor R1 is connected to the signal output terminal of the surge protection circuit 100, and the second resistor R2 is connected to the first resistor R1. The first conditioning circuit 212 performs signal conditioning through the first resistor R1 and the second resistor R2, reducing the voltage amplitude of the CP signal proportionally to the detectable range of the MCU_ADC, such as the voltage range of 0V to 5V.

[0039] The buffer circuit 213 is a buffer circuit with high input impedance and low output impedance, consisting of a third resistor R3 and a follower circuit, to ensure that the signal is not distorted during transmission.

[0040] The first filter circuit 214 includes a low-pass filter composed of a fourth resistor and a first capacitor. The first filter circuit 214 can eliminate high-frequency noise interference and ensure the sampling accuracy of the ADC.

[0041] In some embodiments, the duty cycle detection branch includes a conversion circuit 215, a discharge circuit 216, and a second filter circuit 217. The conversion circuit 215 converts the target detection signal output from the surge protection circuit 100 to obtain a converted signal. The discharge circuit 216 is connected to both the surge protection circuit 100 and the conversion circuit 215, and performs a discharge operation. The second filter circuit 217 is connected to the conversion circuit 215, filters the converted signal to obtain a second filtered signal, and obtains the duty cycle detection signal at the second signal output terminal based on the second filtered signal.

[0042] In some embodiments, the conversion circuit 215 includes a semiconductor component, the discharge circuit 216 includes a fifth resistor and a first diode, and the second filter circuit 217 includes a sixth resistor and a second capacitor. The first terminal of the fifth resistor is connected to the signal output terminal of the surge protection circuit 100 and the cathode of the first diode, respectively. The second terminal of the fifth resistor is connected to the anode of the first diode and the first terminal of the semiconductor component, respectively. The second terminal of the semiconductor component is connected to the first terminal of the sixth resistor, and the second terminal of the sixth resistor is connected to the first terminal of the second capacitor and the second signal output terminal, respectively. The second terminal of the second capacitor and the third terminal of the semiconductor component are grounded.

[0043] like Figure 3 As shown, when the duty cycle detection branch is working, the signal is converted by the conversion circuit 215. The conversion circuit 215 can also ensure the stability of the signal based on the bleed circuit, and then the signal is smoothed by the second filter circuit so that the duty cycle can be calculated by the MCU based on the processed signal.

[0044] The conversion circuit 215 includes a semiconductor component Q1 composed of PNP and NPN semiconductors, which can accurately convert 12V PWM signals to 5V logic levels to ensure matching with the MCU input level.

[0045] The discharge circuit 216 includes a first diode D1 and a fifth resistor R5. The first diode D1 serves as a freewheeling diode, providing a fast current discharge path to ensure the fast response of the PWM signal edge and the integrity of the waveform.

[0046] The second filter circuit 217 includes a low-frequency filter composed of a sixth resistor and a second capacitor. The second filter circuit 217 can smooth the converted PWM signal and input the filtered signal into the MCU at the second signal output terminal MCU_duty_cycle_in, so that the MCU can calculate the duty cycle.

[0047] The first sampling circuit 210 in this embodiment can automatically isolate the main sampling circuit under abnormal conditions to prevent fault propagation. Simultaneously, the voltage detection accuracy of the first sampling circuit 210 reaches ±1%, and the duty cycle detection accuracy can reach ±0.5%. As the main sampling circuit of the detection module, the first sampling circuit 210 in this embodiment has a signal processing response time of less than 50μs, which can meet the requirements of real-time detection.

[0048] In some embodiments, please refer to Figure 4 , Figure 4 This is a circuit diagram of a second sampling circuit and a signal injection circuit provided for an embodiment of this application. (See diagram below.) Figure 4 As shown, the second sampling circuit 220 includes an isolation circuit 221, a second conditioning circuit 222, and a third filtering circuit 223. The isolation circuit 221 is connected to the signal output terminal of the surge protection circuit 100, and isolates the target detection signal. The second conditioning circuit 222 is connected to the isolation circuit 221, and performs level conversion on the target detection signal to obtain a converted signal. The third filtering circuit 223 is connected to the second conditioning circuit 222, and filters the converted signal, obtaining the second sampling signal based on the filtered converted signal.

[0049] The second sampling circuit 220 is a redundant sampling circuit in the function detection circuit 200. It is used to assist the result judgment of the first sampling circuit 210 and operates in the event of a failure of the first sampling circuit 210. Please continue reading. Figure 4 In some embodiments, the isolation circuit 221 includes a seventh resistor and an optocoupler, the second conditioning circuit 222 includes an eighth resistor, a ninth resistor, and a first switching transistor, and the third filter circuit 223 includes a tenth resistor and a third capacitor. The first terminal of the seventh resistor is configured to be connected to the signal output terminal of the surge protection circuit 100. The second terminal of the seventh resistor is connected to the first terminal of the optocoupler. The second terminal of the optocoupler is connected to the first terminals of the eighth and ninth resistors, respectively. The second terminal of the eighth resistor is connected to the first terminal of the first switching transistor and a power signal, respectively. The control terminal of the first switching transistor is connected to the second terminal of the ninth resistor. The second terminal of the first switching transistor is connected to the first terminal of the tenth resistor. The second terminal of the tenth resistor is connected to the first terminal of the third capacitor, and the second terminal of the third capacitor is grounded.

[0050] The isolation circuit 221 in the second sampling circuit 220 includes a current-limiting resistor R7 (seventh resistor) and an optocoupler Q2. The seventh resistor R7 provides current-limiting protection for the input PWM signal, preventing overcurrent damage to subsequent circuits. The optocoupler Q2 achieves electrical isolation between the input signal and subsequent circuits, effectively suppressing common-mode interference and improving system safety. The primary-side circuit of the optocoupler Q2 receives the PWM signal from the CP_in port, achieving isolated signal transmission through the optocoupler Q2.

[0051] The second conditioning circuit 222 includes a level conversion circuit consisting of a pull-up resistor (eighth resistor R8), a pull-down resistor (ninth resistor R9), and a first switching transistor Q3, which can be a MOSFET. The second conditioning circuit 222 converts the signal output from the optocoupler Q2 into a logic level signal recognizable by the MCU. The first switching transistor Q3, acting as a switching device, enables fast signal response and low-power switching. The level-converted signal can be transmitted to the internal processing unit of the MCU through the MCU_CP_in port of the second sampling circuit 220.

[0052] The third filter circuit 223 includes an RC low-pass filter network consisting of the tenth resistor R10 and the third capacitor C3, which effectively filters out high-frequency noise and interference signals and smooths the signal to ensure the waveform stability of the duty cycle sampling signal input to the MCU and improve the duty cycle detection accuracy.

[0053] The second sampling circuit 220 in this embodiment is a redundant sampling circuit. It achieves strong and weak current isolation through optocouplers, ensuring system safety and reliability. Furthermore, a precise signal conditioning circuit ensures a duty cycle detection accuracy of ±0.1%. Multiple filtering and shielding designs effectively suppress electromagnetic interference. Through optimized circuit parameters, the second sampling circuit 220 ensures a signal response time of less than 10 μs.

[0054] In some embodiments, please continue reading Figure 4 The CP signal detection module also includes a signal injection circuit 300. The signal injection circuit 300 is connected to the surge protection circuit 100 and is configured to input a test signal to the surge protection circuit 100 when the CP signal detection module is not connected to the charging pile, so that the function detection circuit 200 performs function detection based on the test signal.

[0055] This application embodiment also includes a signal injection circuit 300, which can inject a test signal when no CP signal is connected, so as to perform self-test based on the test signal, thereby improving the circuit detection efficiency and reliability.

[0056] In some embodiments, the signal injection circuit 300 includes: a second relay, a second diode, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a first switch, and a signal generator. The first terminal of the second relay is connected to the signal receiving terminal of the surge protection circuit 100. The second terminal of the second relay is connected to the negative terminal of the second diode. The positive terminal of the second diode is connected to the first terminal of the eleventh resistor, the first terminal of the fourth capacitor, and the first terminal of the signal generator. The second terminal of the signal generator is grounded through the twelfth resistor. The third terminal of the signal generator is connected to the first terminal of the fifth capacitor and the first terminal of the first switch. The fourth terminal of the signal generator is connected to the second terminal of the first switch through the thirteenth resistor. The second terminals of the fourth capacitor, the twelfth resistor, and the fifth capacitor are grounded.

[0057] like Figure 4 As shown, the signal injection circuit 300 uses the signal generator as a fault signal source. The duty cycle of the signal emitted by the signal generator is adjusted through the twelfth resistor R12 to generate a standard fault test signal. The eleventh resistor R11 is a pull-up resistor, used to ensure the stability of the PWM signal output and prevent signal drift. The fourth capacitor C4 is a filter capacitor, used to smooth and filter the output test signal, improving the signal quality. The second diode D2 is a protection diode, used to prevent negative voltage signals from entering the signal generator chip, providing reverse voltage protection for the signal generator. The fifth capacitor C5 is a power supply filter capacitor, used to ensure the power supply stability of the signal generator chip and reduce power supply noise interference.

[0058] The signal injection circuit 300 also limits the control signal MCU_EN of the signal generator through the thirteenth current-limiting resistor R13 to protect the control port of the signal generator. The second relay K2 is a normally open relay used to control the on / off state of the signal, achieving precise injection of the test signal. The first switch SW1 controls the power supply state of the signal generator, enabling low-power management. The EN control port of the signal generator can control the enable output of the PWM signal through the MCU_EN signal output from the MCU central controller.

[0059] The signal injection circuit 300 in this embodiment can achieve precise control and timing management of fault injection through the MCU central controller. It employs SW1 power supply control and EN port enable control to effectively reduce system standby power consumption. Simultaneously, the duty cycle of the signal generator in the signal injection circuit 300 is adjustable, supporting flexible configuration for different fault modes. The signal injection circuit in this embodiment ensures long-term stable system operation through a robust protection circuit design, and its modular design facilitates system integration and maintenance, providing a reliable test signal source for system fault diagnosis.

[0060] In some embodiments, please refer to Figure 5 , Figure 5 This is a circuit diagram of a surge protection circuit provided in an embodiment of this application. Figure 5 As shown, the surge protection circuit 100 includes: a gas discharge tube, a thermistor, and a transient voltage suppressor connected in sequence; the gas discharge tube is configured to discharge a first surge signal whose energy is greater than an energy threshold; the thermistor is configured to limit current in an overcurrent state; and the transient voltage suppressor is configured to clamp voltage in a surge state.

[0061] like Figure 5 As shown, the surge protection circuit 100 of this application embodiment adopts a three-level cooperative protection architecture, including a gas discharge tube, a thermistor and a transient voltage suppressor connected in sequence.

[0062] The gas discharge tube (GDT) can discharge the first surge signal exceeding the energy threshold. When a high-energy surge event occurs, the GDT activates and safely discharges the large-energy surge signal to the ground system, preventing the energy impact from being transmitted to subsequent circuits.

[0063] PTC thermistors can provide overcurrent protection. When a system encounters a large current injection, i.e., an overcurrent event occurs, the PTC thermistor increases its impedance by heating up, thereby limiting the overcurrent. Its positive temperature coefficient of resistance effectively limits abnormal current, achieving overcurrent protection.

[0064] Transient voltage suppressors (TVS) provide transient protection. In the event of a general surge, a TVS device can respond quickly, using voltage clamping to limit transient overvoltages to a safe range, protecting downstream sensitive circuitry from damage.

[0065] This application embodiment combines three levels of protection—gas discharge tube, thermistor, and transient voltage suppressor—to improve surge protection capability by over 300% compared to traditional single TVS protection solutions. The response times of each protection device are complementary to optimize response speed, achieving nanosecond-level rapid protection response. The surge protection circuit 100 of this application embodiment can withstand larger surge impacts, and the multiple protection mechanisms ensure stable system operation and high reliability under various abnormal operating conditions. Applying this surge protection circuit 100 to a CP signal detection module provides comprehensive and reliable overvoltage and overcurrent protection for the charging system.

[0066] The detection principle of CP signal detection in this application embodiment will be explained below through an example.

[0067] like Figure 6 As shown, Figure 6This is a schematic diagram illustrating the workflow of a CP signal detection module provided in an embodiment of this application. When the CP signal detection module is in operation, it includes the following steps S610 to S670.

[0068] Step S610: Determine the connection status of the charging pile.

[0069] If the charging station is not inserted, proceed to step S620; if the charging station is inserted, proceed to step S670.

[0070] Step S620: Inject test signal.

[0071] The test signal is generated by the signal injection circuit.

[0072] Step S630: Determine the state of the first sampling circuit and the second sampling circuit based on the test signal.

[0073] The circuit state of the first sampling circuit is obtained based on the first sampled signal and the test signal. The circuit state of the second sampling circuit is obtained based on the second sampled signal and the test signal.

[0074] If both the first sampling circuit and the second sampling circuit are in normal condition, proceed to step S640; if the first sampling circuit is normal but the second sampling circuit is faulty, proceed to step S650; if the first sampling circuit is faulty but the second sampling circuit is normal, proceed to step S660.

[0075] In step S640, the charging operation is performed normally, and when the vehicle is powered off, the process returns to step S620 for another self-check.

[0076] If both the first and second sampling circuits are functioning normally and the detection results are consistent with the test signal, the system is determined to be in an abnormal state. Before powering off the vehicle, the test signal is injected again to verify the first and second sampling circuits.

[0077] In step S650, the second sampling circuit is disabled, and the normal charging process is executed.

[0078] If a fault is confirmed in the second sampling circuit, it is shut down and isolated to prevent signal crosstalk. The first sampling circuit continues to operate normally, maintaining normal charging power and ensuring charging efficiency is unaffected. Simultaneously, the onboard controller issues an alarm indicating a fault in the second sampling circuit, prompting maintenance.

[0079] In step S660, the first sampling circuit is disabled and a power reduction charging process is executed.

[0080] If a fault is confirmed in the first sampling circuit, it is shut down and isolated to prevent signal crosstalk. The second sampling circuit operates normally, and the system operates at reduced power to ensure the vehicle can be fully charged for driving to a repair shop. Simultaneously, the onboard controller issues an alarm indicating a fault in the first sampling circuit, prompting the driver to request repair.

[0081] Step S670: Perform normal charging operation.

[0082] To avoid duplicate testing, the charging process is directly based on the self-test results of the previous cycle.

[0083] If the self-test indicates a fault in the first sampling circuit, execute a reduced-power charging procedure. If the self-test indicates a fault in the second sampling circuit, execute a normal-power charging procedure. If both sampling circuits are functioning correctly, execute a standard charging procedure. During charging, continuously monitor the CP signal status to ensure charging safety.

[0084] This application embodiment can automatically identify the operating status of the primary sampling circuit and the redundant secondary sampling circuit, and intelligently identify faults. This application embodiment can automatically isolate abnormal circuits to prevent signal interference, and can also provide corresponding alarm prompts according to the severity of the fault, while still providing emergency charging functionality in a faulty state. Periodic self-tests can detect potential faults in advance.

[0085] The embodiments of this application can effectively improve the safety and reliability of electric vehicle charging systems, providing users with a more intelligent and safer charging experience.

[0086] Secondly, this application also provides a charging socket installed in a vehicle. The charging socket of this application includes a socket body, a signal processing module, and a CP signal detection module. The socket body is configured to connect to a charging pile via a charging gun; the CP signal detection module is installed within the cavity of the socket body and is configured to determine its status data based on a target detection signal. The signal processing module is connected to the CP signal detection module and is configured to obtain charging control data based on the status data.

[0087] Please see Figure 7 , Figure 7 This is a connection diagram of a CP signal detection module provided in an embodiment of this application. Figure 7 As shown, the charging socket body is connected to the electric vehicle charging interface. The CP signal detection module is directly integrated inside the charging socket body. The signal processing unit (OBC) is connected to the CP signal detection module and is used to analyze and process the CP signal collected by the CP signal detection module, and, in conjunction with control signals such as the CC signal transmitted by the charging pile, control the enable state and current magnitude of the charging operation.

[0088] The charging socket in this embodiment can adopt a sealed protective structure with a protection level of IP54 or higher. Simultaneously, a heat dissipation channel is provided inside the charging socket to control the temperature of the circuit module. A standardized interface is provided inside the charging socket to facilitate module installation and replacement.

[0089] The CP signal detection module in this embodiment is installed in a dedicated cavity within the charging socket body and connected to the vehicle control system via a standardized interface. After the vehicle control system is activated, it can monitor changes in the CP signal in real time through the CP signal detection module.

[0090] In summary, the technical solutions of the embodiments of this application have at least the following advantages.

[0091] First, related technologies incorporate a CP signal detection device in the on-board charger (OBC) or battery management system (BMS). In cases where the CP signal detection circuit is damaged due to external factors, repairing the detection device requires complete disassembly, resulting in poor maintainability, high repair complexity, and high costs. This application's embodiment integrates the CP signal detection circuit into the charging interface device, improving repairability and reducing maintenance costs.

[0092] Secondly, related technologies use isolation devices such as optocouplers for signal level conversion, resulting in overly simplistic circuit principles. This leads to poor detection accuracy of the CP signal amplitude and duty cycle, easily causing abnormal charging interruptions or charging current mismatches, resulting in excessively long charging times and overcurrent. This application's embodiment divides the input CP signal into two parts: voltage measurement and duty cycle calculation, implemented through independent circuits. This controls the amplitude voltage accuracy, duty cycle waveform quality, and rise and fall times, thereby improving detection accuracy.

[0093] Third, the surge protection of related technologies is limited. For example, using a single TVS for surge protection of the entire circuit results in insufficient coverage and may lead to unexpected circuit failure. This application's embodiments improve the protection level by employing multi-layer surge protection devices to enhance protection capabilities.

[0094] Fourth, the functional detection circuits of related technologies lack any feedback mechanism and fault diagnosis component, and therefore lack early warning capabilities. This can lead to situations where the vehicle, after its battery is depleted, cannot be charged in time for slow charging, impacting the user experience. This application's embodiment uses hardware self-testing, performing self-tests when the vehicle is powered on and off. This can diagnose latent functional faults in the charging CP signal functional detection circuit and also provides a degraded CP signal functional detection circuit as a redundant backup.

[0095] In summary, the CP signal function detection circuit of this application embodiment can not only prevent interference from surges and static electricity, improving detection accuracy, but also perform circuit failure detection and is easy to repair. The function detection circuit of this application embodiment can solve the problem of circuit damage caused by lightning surges during charging, improve the maintainability of the electric vehicle, diagnose circuit faults in advance, and enable drivers to prepare corresponding strategies.

[0096] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0097] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A CP signal detection module, characterized in that, include: The surge protection circuit (100) includes a signal receiving end and a signal output end. The signal receiving end receives an initial detection signal, and the surge protection circuit (100) is configured to perform a protection operation on the initial detection signal and then output a target detection signal at the signal output end. The initial detection signal includes a CP signal or a test signal input from the charging pile. A function detection circuit (200) is connected to the surge protection circuit (100), and the function detection circuit (200) is configured to determine the circuit state of the function detection circuit (200) based on the target detection signal.

2. The module according to claim 1, characterized in that, The function detection circuit (200) includes a first sampling circuit (210) and a second sampling circuit (220). The first sampling circuit (210) and the second sampling circuit (220) are respectively connected to the surge protection circuit (100). The first sampling circuit (210) is configured to sample the target detection signal to obtain a first sampling signal, and the second sampling circuit (220) is configured to sample the target detection signal to obtain a second sampling signal. The function detection circuit (200) determines the circuit state of the function detection circuit (200) based on the first sampling signal and the second sampling signal.

3. The module according to claim 2, characterized in that, The first sampling signal includes an amplitude detection signal and a duty cycle detection signal, and the first sampling circuit (210) includes: A voltage amplitude detection branch includes a first signal input terminal and a first signal output terminal. The voltage amplitude detection branch is configured to obtain an amplitude detection signal at the first signal output terminal based on the target detection signal input at the first signal input terminal. The duty cycle detection branch includes a second signal input terminal and a second signal output terminal. The duty cycle detection branch is configured to input the target detection signal at the second signal input terminal and obtain the duty cycle detection signal at the second signal output terminal.

4. The module according to claim 3, characterized in that, The voltage amplitude detection branch includes: A first isolation circuit (211) is connected to the signal receiving end of the surge protection circuit (100). The first isolation circuit (211) is configured to determine the input state of the signal receiving end and the initial detection signal based on the circuit state of the sampling circuit. The first conditioning circuit (212) is connected to the signal output terminal of the surge protection circuit (100). The first conditioning circuit (212) is configured to condition the target detection signal to obtain a conditioning signal. A buffer circuit (213) is connected to the first conditioning circuit (212), and the buffer circuit (213) is configured to buffer the conditioning signal to obtain a buffered signal; The first filtering circuit (214) is connected to the buffer circuit (213). The first filtering circuit (214) is configured to filter the buffer signal to obtain a first filtered signal, and obtain the amplitude detection signal at the first signal output terminal based on the first filtered signal.

5. The module according to claim 4, characterized in that, The first isolation circuit (211) includes a first relay, the first conditioning circuit (212) includes a first resistor and a second resistor, the buffer circuit (213) includes a third resistor and a follower circuit, and the first filter circuit (214) includes a fourth resistor and a first capacitor; wherein, The first relay is connected to the signal receiving terminal of the surge protection circuit (100), the first end of the first resistor is connected to the signal output terminal of the surge protection circuit (100), the second end of the first resistor is connected to the first end of the second resistor and the first end of the third resistor, the second end of the third resistor is connected to the follower circuit, the second end of the follower circuit is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the first end of the first capacitor and the first signal output terminal, and the second end of the second resistor and the second end of the first capacitor are grounded.

6. The module according to claim 3, characterized in that, The duty cycle detection branch includes: The conversion circuit (215) is configured to convert the target detection signal output by the surge protection circuit (100) to obtain a converted signal; The discharge circuit (216) is connected to the surge protection circuit (100) and the conversion circuit (215) respectively, and the discharge circuit (216) is configured to perform a discharge operation; The second filtering circuit (217) is connected to the conversion circuit (215). The second filtering circuit (217) is configured to filter the conversion signal to obtain a second filtered signal, and obtain the duty cycle detection signal at the second signal output terminal based on the second filtered signal.

7. The module according to claim 6, characterized in that, The conversion circuit (215) includes semiconductor components, the discharge circuit (216) includes a fifth resistor and a first diode, and the second filter circuit (217) includes a sixth resistor and a second capacitor; wherein, The first end of the fifth resistor is connected to the signal output terminal of the surge protection circuit (100) and the negative terminal of the first diode, respectively. The second end of the fifth resistor is connected to the positive terminal of the first diode and the first end of the semiconductor component, respectively. The second end of the semiconductor component is connected to the first end of the sixth resistor, respectively. The second end of the sixth resistor is connected to the first end of the second capacitor and the second signal output terminal, respectively. The second end of the second capacitor and the third end of the semiconductor component are grounded.

8. The module according to claim 2, characterized in that, The second sampling circuit (220) includes: The second isolation circuit (221) is connected to the signal output terminal of the surge protection circuit (100), and the second isolation circuit (221) is configured to isolate the target detection signal; The second conditioning circuit (222) is connected to the second isolation circuit (221), and the second conditioning circuit (222) is configured to perform level conversion on the target detection signal to obtain a converted signal; The third filter circuit (223) is connected to the second conditioning circuit (222). The third filter circuit (223) is configured to filter the converted signal and obtain the second sampled signal based on the filtered converted signal.

9. The module according to claim 8, characterized in that, The second isolation circuit (221) includes a seventh resistor and an optocoupler; the second conditioning circuit (222) includes an eighth resistor, a ninth resistor, and a first switching transistor; and the third filter circuit (223) includes a tenth resistor and a third capacitor. The first end of the seventh resistor is configured to be connected to the signal output terminal of the surge protection circuit (100). The second end of the seventh resistor is connected to the first end of the optocoupler. The second end of the optocoupler is connected to the first end of the eighth resistor and the first end of the ninth resistor. The second end of the eighth resistor is connected to the first end of the first switch and the power signal. The control terminal of the first switch is connected to the second end of the ninth resistor. The second end of the first switch is connected to the first end of the tenth resistor. The second end of the tenth resistor is connected to the first end of the third capacitor. The second end of the third capacitor is grounded.

10. The module according to claim 1, characterized in that, The CP signal detection module also includes: A signal injection circuit (300) is connected to the surge protection circuit (100). The signal injection circuit (300) is configured to input the test signal to the surge protection circuit (100) when the CP signal detection module is not connected to the charging pile, so that the function detection circuit (200) performs function detection based on the test signal.

11. The module according to claim 10, characterized in that, The signal injection circuit (300) includes: a second relay, a second diode, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a first switch, and a signal generator. The first terminal of the second relay is connected to the signal receiving terminal of the surge protection circuit (100). The second terminal of the second relay is connected to the negative terminal of the second diode. The positive terminal of the second diode is connected to the first terminal of the eleventh resistor, the first terminal of the fourth capacitor, and the first terminal of the signal generator. The second terminal of the signal generator is grounded through the twelfth resistor. The third terminal of the signal generator is connected to the first terminal of the fifth capacitor and the first terminal of the first switch. The fourth terminal of the signal generator is connected to the second terminal of the first switch through the thirteenth resistor. The second terminals of the fourth capacitor, the twelfth resistor, and the fifth capacitor are grounded.

12. The module according to claim 1, characterized in that, The surge protection circuit (100) includes: a gas discharge tube, a thermistor, and a transient voltage suppressor connected in sequence; wherein, The gas discharge tube is configured to discharge a first surge signal, the energy of which is greater than an energy threshold. The thermistor is configured to limit current in an overcurrent state; The transient voltage suppressor is configured to perform voltage clamping under surge conditions.

13. A charging socket, characterized in that, The charging socket, installed in the vehicle, includes a socket body, a signal processing module, and a CP signal detection module as described in any one of claims 1 to 12; wherein, The socket body is configured to connect to the charging pile via a charging gun; The CP signal detection module is installed in the cavity of the socket body, and the CP signal detection module is configured to determine the status data of the CP signal detection module based on the target detection signal; The signal processing module, connected to the CP signal detection module, is configured to obtain charging control data based on the status data.

Images