Anti-interference control method of communication controller applied to electric vehicle

Abstract

The application discloses a communication controller anti-interference control method applied to an electric vehicle and relates to the technical field of charging control.The method comprises the following steps: based on a charging mode, a connection path of a relay switching CP signal is controlled; when it is identified as a direct current fast charging mode, the relay is attracted to make the CP signal connected to an electric vehicle communication controller through the normally open contact of the relay and physically disconnected from a vehicle-mounted charger; when it is identified as an alternating current slow charging mode, the relay is disconnected to switch the CP signal to the vehicle-mounted charger; a plug-in gun wake-up circuit, a key wake-up circuit and a CP signal wake-up circuit are configured, and the output ends of the wake-up circuits are connected in parallel to a local wake-up signal node; a master control unit monitors the level state of the local wake-up signal node; when any wake-up circuit is triggered and causes the local wake-up signal node to generate an effective level jump, the electric vehicle communication controller is controlled to exit a sleep state and start up.

Description

Technical Field

[0001] This invention relates to the field of charging control technology, specifically to an anti-interference control method for a communication controller used in electric vehicles. Background Technology

[0002] The electric vehicle communication controller is a core component for converting communication protocols between electric vehicles and charging stations, and its operational stability directly affects charging safety and efficiency. In traditional designs, strong electromagnetic interference generated by the on-board charger during operation is conducted to the communication controller through the directly connected CP signal line, affecting its reliability. Furthermore, existing wake-up circuits cannot effectively wake the charging gun from sleep mode using ignition or the CP signal, requiring the charging gun to be unplugged and replugged, leading users to misinterpret it as a device malfunction. Traditional power supply solutions are incompatible with the different battery voltage ranges of passenger and commercial vehicles, and are prone to damaging controller components when voltage is abnormal. These problems severely restrict the stability of electric vehicle charging systems and the user experience. Summary of the Invention

[0003] The purpose of this invention is to provide an anti-interference control method for a communication controller applied to electric vehicles, in order to solve the problems raised in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an anti-interference control method for a communication controller of an electric vehicle, the method comprising: Based on the charging mode control relay switching CP signal connection path, the default initial state is DC fast charging mode. When DC fast charging mode is detected, the control relay is activated, so that the CP signal is connected to the electric vehicle communication controller through the normally open contact of the relay and physically disconnected from the on-board charger. When AC slow charging mode is detected, the control relay is deactivated, and the CP signal is switched to the on-board charger. The system is equipped with a gun-activated wake-up circuit, a key-activated wake-up circuit, and a CP signal-activated wake-up circuit. Each wake-up circuit has a unidirectional diode and an RC delay filter circuit. The outputs of the three wake-up circuits are connected in parallel to the local wake-up signal node to ensure that the wake-up sources do not interfere with each other. The wide-range voltage provided by the electric vehicle battery is converted and stabilized to 12V through a wide-voltage input DC-DC converter circuit to power the electric vehicle communication controller and its load. The main control unit continuously monitors the level status of the local wake-up signal node. When any wake-up circuit is triggered and causes a valid level transition in the local wake-up signal node, the electric vehicle communication controller is controlled to exit the sleep state and power on to start.

[0005] According to the above scheme, the connection path for controlling the relay switching CP signal based on the charging mode includes: The microcontroller outputs a CP switch control signal to the relay drive circuit, which includes a base current limiting resistor, an NPN transistor, and a freewheeling diode connected in parallel across the relay coil. The base current limiting resistor limits the current flowing from the microcontroller pin into the base of the NPN transistor to prevent excessive current from damaging the microcontroller and the NPN transistor. The freewheeling diode is connected in reverse parallel across the relay coil to discharge the reverse induced electromotive force when the relay coil is de-energized. When the DC fast charging mode is detected, the CP switch control signal is high, which controls the NPN transistor to conduct, energizes the relay coil, and the normally open contact of the relay is energized. The CP signal of the charging interface is connected to the electric vehicle communication controller through the normally open contact of the relay. When the AC slow charging mode is detected, the CP switch control signal is low, which controls the NPN transistor to turn off, de-energizes the relay coil, opens the normally open contact of the relay, and switches the CP signal of the charging interface to the on-board charger.

[0006] According to the above scheme, the gun-activated wake-up circuit includes: When the charging gun is inserted, the charging gun wake-up signal transitions from low to high. The wake-up signal is unidirectionally conducted via a switching diode, which prevents reverse voltage flow within the circuit, protecting the charging gun connector circuit. An RC delay filter circuit performs RC delay filtering on the wake-up signal. This circuit consists of a resistor and a capacitor connected in series. One end of the resistor is connected to the cathode of the diode, and one end of the capacitor is grounded. The connection point of the resistor and capacitor serves as the filter output point. This output point eliminates transient interference, ensuring a stable wake-up signal. The wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and conduct. The collector of the NPN transistor pulls the local wake-up signal node from high to low, generating the wake-up signal. When the NPN transistor is not conducting, the local wake-up signal node is stably pulled high through a pull-up resistor, ensuring stable node levels in sleep mode.

[0007] According to the above scheme, the key wake-up circuit includes: When the ignition switch is turned on, the key wake-up signal changes from low to high level. It is then unidirectionally turned on by a switching diode, which prevents the internal voltage from affecting the ignition switch power supply system in reverse, thus achieving circuit isolation protection. An RC delay filter circuit further filters the key wake-up signal. This circuit, with a resistor and capacitor in series, filters out mechanical jitter or circuit noise generated during ignition switch operation, preventing false triggering. The key wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and pull the local wake-up signal node from high to low, generating the wake-up signal. When the NPN transistor is off, the local wake-up signal node is maintained at a high level by a pull-up resistor, ensuring stable system sleep mode.

[0008] According to the above scheme, the CP signal wake-up circuit includes: When the CP signal is input, the CP wake-up signal generates a level transition. It is then unidirectionally turned on by a switching diode, which prevents reverse voltage flow from the internal circuit to the CP signal input, protecting the communication link between the charging pile and the electric vehicle. An RC delay filter circuit, consisting of a resistor and capacitor in series, eliminates high-frequency interference during CP signal transmission, ensuring the wake-up signal is valid. The CP wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and pull the local wake-up signal node from high to low, generating the wake-up signal. When the NPN transistor is off, the local wake-up signal node remains high through a pull-up resistor, ensuring the system remains in a stable sleep state when not woken up.

[0009] According to the above scheme, the wide-input DC-DC converter circuit converts the wide-range input voltage of the battery into a stable 12V output voltage, including: The wide-range voltage output from the electric vehicle battery is input into the DC-DC converter chip and filtered to remove wide-band noise and provide instantaneous high current. The filtering process includes a parallel input filter network, which includes multiple capacitance values. These multiple capacitance values ​​are connected in parallel between the voltage input pin of the DC-DC converter chip and ground. Different capacitance values ​​filter out noise in different frequency bands, working together to ensure the purity of the input voltage. The DC-DC converter chip is triggered to enter the working state by an enable circuit. The enable circuit includes a resistor and a capacitor. The resistor pulls up the input voltage to complete the power-on self-start, and the capacitor filters out the interference of the enable signal to ensure stable chip triggering and start-up, avoiding start-up failure due to signal fluctuations. The switching frequency of the power switch of the DC-DC converter chip is set by an external resistor. Based on the periodic on and off of the switching frequency, the input voltage is converted into a high-frequency pulse voltage. During the conduction period of the power switch, a bootstrap circuit provides a drive level higher than the switching node voltage to the upper transistor inside the chip. The bootstrap circuit includes a bootstrap capacitor and an auxiliary capacitor, which are connected in parallel between the bootstrap pin and the switching node pin of the chip to stably provide the drive voltage, ensure that the upper transistor power switch is fully turned on, and improve the voltage conversion efficiency. An LC filter network smooths the high-frequency pulse voltage into a stable DC voltage. The LC filter network includes a power inductor and an output capacitor. The power inductor stores and releases energy, while the output capacitor further filters out residual high-frequency ripple. Together, they stabilize the output voltage. Simultaneously, a feedback network samples the output DC voltage in real time and feeds it back to the switching power supply chip, dynamically adjusting the switching duty cycle to maintain a stable output voltage. The feedback network includes voltage divider resistors connected in series between the output terminal and ground. The sampled voltage is input to the chip via the feedback pin. The chip dynamically adjusts the switching duty cycle based on the difference between the sampled voltage and the internal reference voltage to maintain a stable output voltage of 12V. During startup, the rising slope of the output DC voltage is controlled by a soft-start circuit to suppress the surge current generated at startup. The soft-start circuit includes a soft-start capacitor connected between the soft-start pin of the chip and ground. During the charging process, the output voltage is gradually increased to avoid instantaneous large current impacting the front-end battery and the rear-end load. The output DC voltage status is monitored by a power status indicator circuit. When the output DC voltage stabilizes, an indicator signal is generated and synchronously fed back to the main control unit for the main control unit to determine whether the power supply is normal.

[0010] According to the above scheme, the DC-DC conversion circuit has a power status indication circuit, which includes an open-drain output power good indicator pin and a series branch of a light-emitting diode and a current-limiting resistor. The power good indicator pin is a dedicated pin of the DC-DC conversion chip, used to output a power status signal. When the output voltage is unstable, the pin is at a low level and becomes a high-impedance state after stabilization. The current-limiting resistor is used to limit the current flowing through the light-emitting diode to prevent the diode from burning out due to excessive current. Once the output DC voltage is stabilized, the power good indicator pin changes to a high impedance state, and the LED lights up.

[0011] According to the above scheme, the main control unit continuously detects the level status of the local wake-up signal node through the input and output ports; when the local wake-up signal node transitions from high level to low level, the main control unit recognizes it as a valid wake-up event; the main control unit controls the power management circuit to provide operating voltage to the electric vehicle communication controller; the main control unit sends a reset signal to the electric vehicle communication controller, causing the electric vehicle communication controller to exit the sleep state and enter the normal operation mode.

[0012] According to the above scheme, after the main control unit controls the electric vehicle communication controller to power on and start, it continues to monitor the level status of the local wake-up signal node. When all wake-up signals disappear and the local wake-up signal node returns to a high level and remains high for a preset duration (the preset duration is a stable period of time to ensure no wake-up needs and avoid false sleep caused by short-term level fluctuations), the main control unit controls the electric vehicle communication controller to enter a sleep state and cuts off the working power of the electric vehicle communication controller. Cutting off the working power includes turning off the power supply to the non-core circuits of the electric vehicle communication controller and only retaining a weak power supply to the wake-up detection related circuits to reduce system power consumption and extend battery life.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a relay to physically switch the CP signal path, completely disconnecting the connection with the on-board charger during DC fast charging, thus preventing electromagnetic interference generated by the on-board charger from being transmitted to the communication controller, improving anti-interference capability and operational stability. 2. This invention enables the communication controller to wake up on demand and automatically go into sleep mode by continuously monitoring and intelligently judging the wake-up signal through the main control unit, effectively reducing the system's standby power consumption while ensuring timely response. 3. This invention adopts a wide-voltage input DC-DC conversion circuit, which is compatible with different battery voltages of passenger cars and commercial vehicles. Through multi-stage filtering, feedback voltage regulation and soft-start design, it ensures that the communication controller works stably in voltage fluctuation environment. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the steps of the anti-interference control method for a communication controller applied to an electric vehicle according to the present invention. Figure 2 This is a relay drive circuit diagram of the anti-interference control method for the communication controller of an electric vehicle according to the present invention; Figure 3 This is a circuit diagram of the plug-in wake-up circuit for the anti-interference control method of the communication controller of the present invention applied to electric vehicles; Figure 4 This is a key wake-up circuit diagram for the anti-interference control method of the communication controller of an electric vehicle according to the present invention; Figure 5This is a circuit diagram of the CP signal wake-up method for the anti-interference control of the communication controller of an electric vehicle, according to the present invention. Figure 6 This is a DC-DC conversion circuit diagram of the anti-interference control method for the communication controller of an electric vehicle, according to the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example: Figures 1-5 As shown, the present invention provides a technical solution for an anti-interference control method for a communication controller of an electric vehicle, the method comprising: Based on the charging mode control relay switching CP signal connection path, the default initial state is DC fast charging mode. When DC fast charging mode is detected, the control relay is activated, so that the CP signal is connected to the electric vehicle communication controller through the normally open contact of the relay and physically disconnected from the on-board charger. When AC slow charging mode is detected, the control relay is deactivated, and the CP signal is switched to the on-board charger. Specifically, the microcontroller outputs a CP switch control signal to the relay drive circuit. The relay drive circuit includes a base current-limiting resistor, an NPN transistor, and a freewheeling diode connected in parallel across the relay coil. The base current-limiting resistor limits the current flowing from the microcontroller pin to the base of the NPN transistor, preventing excessive current from damaging the microcontroller and the NPN transistor. The freewheeling diode is connected in reverse parallel across the relay coil to discharge the reverse induced electromotive force when the relay coil is de-energized. When the DC fast charging mode is detected, the CP switch control signal is high, controlling the NPN transistor to conduct, energizing the relay coil, and closing the normally open contact of the relay. The CP signal of the charging interface is connected to the electric vehicle communication controller through the normally open contact of the relay. When the AC slow charging mode is detected, the CP switch control signal is low, controlling the NPN transistor to cut off, de-energizing the relay coil, opening the normally open contact of the relay, and switching the CP signal of the charging interface to the on-board charger.

[0017] The system is equipped with a gun-activated wake-up circuit, a key-activated wake-up circuit, and a CP signal-activated wake-up circuit. Each wake-up circuit has a unidirectional diode and an RC delay filter circuit. The outputs of the three wake-up circuits are connected in parallel to the local wake-up signal node to ensure that the wake-up sources do not interfere with each other. Specifically, the plug-in wake-up circuit includes: When the charging gun is inserted, the charging gun wake-up signal transitions from low to high. The wake-up signal is unidirectionally conducted via a switching diode, which prevents reverse voltage flow within the circuit, protecting the charging gun connector circuit. An RC delay filter circuit performs RC delay filtering on the wake-up signal. This circuit consists of a resistor and a capacitor connected in series. One end of the resistor is connected to the cathode of the diode, and one end of the capacitor is grounded. The connection point of the resistor and capacitor serves as the filter output point. This output point eliminates transient interference, ensuring a stable wake-up signal. The wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and conduct. The collector of the NPN transistor pulls the local wake-up signal node from high to low, generating the wake-up signal. When the NPN transistor is not conducting, the local wake-up signal node is stably pulled high through a pull-up resistor, ensuring stable node levels in sleep mode.

[0018] Specifically, the key wake-up circuit includes: When the ignition switch is turned on, the key wake-up signal changes from low to high level. It is then unidirectionally turned on by a switching diode, which prevents the internal voltage from affecting the ignition switch power supply system in reverse, thus achieving circuit isolation protection. An RC delay filter circuit further filters the key wake-up signal. This circuit, with a resistor and capacitor in series, filters out mechanical jitter or circuit noise generated during ignition switch operation, preventing false triggering. The key wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and pull the local wake-up signal node from high to low, generating the wake-up signal. When the NPN transistor is off, the local wake-up signal node is maintained at a high level by a pull-up resistor, ensuring stable system sleep mode.

[0019] Specifically, the CP signal wake-up circuit includes: When the CP signal is input, the CP wake-up signal generates a level transition. It is then unidirectionally turned on by a switching diode, which prevents reverse voltage flow from the internal circuit to the CP signal input, protecting the communication link between the charging pile and the electric vehicle. An RC delay filter circuit, consisting of a resistor and capacitor in series, eliminates high-frequency interference during CP signal transmission, ensuring the wake-up signal is valid. The CP wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and pull the local wake-up signal node from high to low, generating the wake-up signal. When the NPN transistor is off, the local wake-up signal node remains high through a pull-up resistor, ensuring the system remains in a stable sleep state when not woken up.

[0020] The wide-range voltage provided by the electric vehicle battery is converted and stabilized to 12V through a wide-voltage input DC-DC converter circuit to power the electric vehicle communication controller and its load. Specifically, the wide-range voltage output from the electric vehicle battery is input into the DC-DC converter chip and filtered to remove wide-band noise and provide instantaneous high current. The filtering process includes a parallel input filter network, which includes multiple capacitance values. These multiple capacitance values ​​are connected in parallel between the voltage input pin of the DC-DC converter chip and ground. Different capacitance values ​​filter out noise in different frequency bands, working together to ensure the purity of the input voltage. The DC-DC converter chip is triggered to enter the working state by an enable circuit. The enable circuit includes a resistor and a capacitor. The resistor pulls up the input voltage to complete the power-on self-start, and the capacitor filters out the interference of the enable signal to ensure stable chip triggering and start-up, avoiding start-up failure due to signal fluctuations. The switching frequency of the power switch of the DC-DC converter chip is set by an external resistor. Based on the periodic on and off of the switching frequency, the input voltage is converted into a high-frequency pulse voltage. During the conduction period of the power switch, a bootstrap circuit provides a drive level higher than the switching node voltage to the upper transistor inside the chip. The bootstrap circuit includes a bootstrap capacitor and an auxiliary capacitor, which are connected in parallel between the bootstrap pin and the switching node pin of the chip to stably provide the drive voltage, ensure that the upper transistor power switch is fully turned on, and improve the voltage conversion efficiency. An LC filter network smooths the high-frequency pulse voltage into a stable DC voltage. The LC filter network includes a power inductor and an output capacitor. The power inductor stores and releases energy, while the output capacitor further filters out residual high-frequency ripple. Together, they stabilize the output voltage. Simultaneously, a feedback network samples the output DC voltage in real time and feeds it back to the switching power supply chip, dynamically adjusting the switching duty cycle to maintain a stable output voltage. The feedback network includes voltage divider resistors connected in series between the output terminal and ground. The sampled voltage is input to the chip via the feedback pin. The chip dynamically adjusts the switching duty cycle based on the difference between the sampled voltage and the internal reference voltage to maintain a stable output voltage of 12V. During startup, the rising slope of the output DC voltage is controlled by a soft-start circuit to suppress the surge current generated at startup. The soft-start circuit includes a soft-start capacitor connected between the soft-start pin of the chip and ground. During the charging process, the output voltage is gradually increased to avoid instantaneous large current impacting the front-end battery and the rear-end load. The output DC voltage status is monitored by a power status indicator circuit. When the output DC voltage stabilizes, an indicator signal is generated and synchronously fed back to the main control unit for the main control unit to determine whether the power supply is normal.

[0021] Furthermore, the DC-DC conversion circuit includes a power status indicator circuit, which comprises an open-drain output power-good indicator pin and a series branch of an LED and a current-limiting resistor. The power-good indicator pin is a dedicated pin of the DC-DC conversion chip, used to output a power status signal. When the output voltage is unstable, this pin is at a low level, and after stabilization, it becomes a high-impedance state. The current-limiting resistor is used to limit the current flowing through the LED to prevent excessive current from burning out the LED. When the output DC voltage is stabilized, the power-good indicator pin becomes a high-impedance state, and at the same time, the LED is lit.

[0022] The main control unit continuously monitors the level status of the local wake-up signal node. When any wake-up circuit is triggered and causes the local wake-up signal node to generate a valid level transition, the electric vehicle communication controller is controlled to exit the sleep state and power on to start. Specifically, the main control unit continuously monitors the level status of the local wake-up signal node through the input / output ports; when the local wake-up signal node transitions from high to low level, the main control unit recognizes it as a valid wake-up event; the main control unit controls the power management circuit to provide operating voltage to the electric vehicle communication controller; the main control unit sends a reset signal to the electric vehicle communication controller, causing the electric vehicle communication controller to exit the sleep state and enter the normal operation mode.

[0023] Furthermore, after the main control unit controls the electric vehicle communication controller to power on and start, it continues to monitor the level status of the local wake-up signal node. When all wake-up signals disappear and the local wake-up signal node returns to a high level and remains high for a preset duration (the preset duration is a stable period of time to ensure no wake-up needs and avoid false sleep caused by short-term level fluctuations), the main control unit controls the electric vehicle communication controller to enter a sleep state and cuts off the operating power of the electric vehicle communication controller. Cutting off the operating power includes turning off the power supply to the non-core circuits of the electric vehicle communication controller, leaving only a weak power supply to the wake-up detection related circuits to reduce system power consumption and extend battery life.

[0024] like Figure 2 As shown, the relay drive circuit consists of relay J3, base current limiting resistor R94, resistor R109, resistor R178, NPN transistor Q1, and freewheeling diode D20. Relay J3 includes pins 1, 2, 3, 4, 5, 6, 7, and 8. Pin 1 of relay J3 is connected to the drive power supply; pin 3 of relay J3 is connected to the electric vehicle communication controller; pin 4 of relay J3 is connected to resistor R178, which is connected to the on-board charger; pin 5 of relay J3 is connected to the CP signal from the charging gun socket; pin 6 of relay J3 is a normally open contact and is connected to pin 5 of relay J3; pin 8 of relay J3 is connected to the collector of NPN transistor Q1. The freewheeling diode D20 is connected in reverse parallel to pins 1 and 8 of relay J3; NPN transistor Q1 includes emitter 2, base 1, and collector 3; emitter 2 of NPN transistor Q1 is grounded; base 1 of NPN transistor Q1 is connected to base current limiting resistor R94; collector 3 of NPN transistor Q1 is connected to pin 8 of relay J3. One end of resistor R109 is connected to the connection node between the base current limiting resistor R94 and the CP_Switch control signal, and the other end is grounded.

[0025] The system operates based on the CP_Switch control signal output by the microcontroller, and switches the CP signal path between the electric vehicle communication controller and the on-board charger by controlling the opening and closing of the relay contacts. When the microcontroller recognizes the DC fast charging mode, the CP_Switch control signal outputs a high level. This high-level signal, after passing through the base current limiting resistor R94, provides sufficient base current to the NPN transistor Q1, causing Q1 to enter saturation conduction. At this time, a circuit is formed in the relay coil, and the coil, when energized, generates a magnetic field, driving the normally open contacts inside the relay to close, making pins 5 and 6 conduct. Meanwhile, the CP signal from the charging gun socket is connected to pin 3 through pins 5 and 6, ultimately reaching the electric vehicle communication controller, while the connection between pin 4 and the on-board charger remains open, achieving physical isolation between the CP signal and the on-board charger.

[0026] When the microcontroller identifies the AC slow charging mode, the CP_Switch control signal outputs a low level. At this time, due to the pull-down resistor R109, the base of Q1 is reliably pulled low to ground potential, and Q1 immediately switches from conducting to cut-off, cutting off the current path to the relay coil. After the coil is de-energized, the magnetic field disappears, the relay contacts reset, pins 5 and 6 disconnect, and pins 5 and 4 resume conduction. At this point, the CP signal is switched to connect to the on-board charger through pin 4 and resistor R178, and disconnected from the electric vehicle communication controller.

[0027] In the circuit, the freewheeling diode D20 is connected in reverse parallel across the coil. At the instant Q1 switches from conducting to cutoff, the relay coil generates an extremely high reverse induced electromotive force (EMF), with its polarity being positive at pin 8 and negative at pin 1. At this moment, D20 immediately conducts in the forward direction, forming a discharge circuit for the induced current in the coil, thereby clamping the collector voltage of Q1 within a safe range and effectively protecting Q1 from breakdown. Resistor R109 ensures that the base potential of Q1 is stably pulled low when the CP_Switch signal is in a high-impedance state or uninitialized, preventing false turn-on. Resistor R178 serves to limit current and match impedance when the CP signal is connected to the on-board charger.

[0028] like Figure 3As shown, the plug-in wake-up circuit consists of a switching diode D4, a filter capacitor C62, a resistor R118, a base current limiting resistor R25, a pull-up resistor R27, and an NPN transistor Q3. The anode of switching diode D4 is connected to the WAKE_PP signal input terminal, and the cathode of switching diode D4 is connected to resistor R118 and filter capacitor C62; the other end of resistor R118 is grounded; one end of base limiting current resistor R25 is connected to filter capacitor C62, and the other end is connected to the base of NPN transistor Q3; the base of NPN transistor Q3 is connected to base limiting current resistor R25, the emitter is grounded, and the collector serves as the output terminal of the wake-up signal, connected to the local wake-up signal node; one end of pull-up resistor R27 is connected to the power supply, and the other end is connected to the collector of NPN transistor Q3 and the local wake-up signal node; When the charging gun is inserted, the WAKE_PP signal changes from low to high level; after being turned on by the switching diode D4, it passes through the RC delay filter circuit composed of resistor R118 and capacitor C62 connected in series; the signal after delay and filtering drives the base of NPN transistor Q3 through the base current limiting resistor R25. When the base voltage of Q3 reaches the conduction threshold, the transistor saturates and conducts, pulling the LOCAL_WAKE signal node, which was originally held at a high level by the pull-up resistor R27, down to a low level. The main control unit detects the downward transition of the LOCAL_WAKE signal and controls the electric vehicle communication controller to exit the sleep state and power on.

[0029] like Figure 4 As shown, the key wake-up circuit consists of a switching diode D12, a current-limiting resistor R184, a filter capacitor C90, a base current-limiting resistor R185, an NPN transistor Q18, and a pull-up resistor R186. The anode of the switching diode D12 is connected to the IGN signal input terminal, and the cathode is connected to the RC delay filter circuit. The RC delay filter circuit includes a current-limiting resistor R184 and a filter capacitor C90. One end of the base current-limiting resistor R185 is connected to the output node of the RC delay filter circuit, and the other end is connected to the base of the NPN transistor Q18. The base of the NPN transistor Q18 is connected to the base current-limiting resistor R185, the emitter of the NPN transistor Q18 is grounded, and the collector of the NPN transistor Q18 is connected to the local wake-up signal node. One end of the pull-up resistor R186 is connected to the power supply, and the other end is connected to the collector of the NPN transistor Q18 and the local wake-up signal node. When the ignition switch is turned on, the IGN signal changes from low level to high level; after being unidirectionally turned on by the switching diode D12, the signal passes through the RC delay filter circuit composed of resistor R184 and capacitor C90 connected in series; the signal after delay and filtering drives the base of NPN transistor Q18 through the base current limiting resistor R185. When the base voltage of Q18 reaches the conduction threshold, the transistor saturates and conducts, pulling the LOCAL_WAKE signal node, which was originally held at a high level by the pull-up resistor R186, down to a low level. The main control unit detects the downward transition of the LOCAL_WAKE signal and controls the electric vehicle communication controller to exit the sleep state and power on.

[0030] like Figure 5 As shown, the CP signal wake-up circuit consists of a switching diode D9, a current-limiting resistor R110, a filter capacitor C63, a base current-limiting resistor R168, an NPN transistor Q16, and a pull-up resistor R120. The anode of the switching diode D9 is connected to the CP_IN signal input terminal, and the cathode is connected to the RC delay filter circuit. The RC delay filter circuit includes a current-limiting resistor R110 and a filter capacitor C63. One end of the base current-limiting resistor R168 is connected to the output node of the RC delay filter circuit, and the other end is connected to the base of the NPN transistor Q16. The base of the NPN transistor Q16 is connected to the resistor R168, the emitter of the NPN transistor Q16 is grounded, and the collector of the NPN transistor Q16 is connected to the LOCAL_WAKE signal node. One end of the pull-up resistor R120 is connected to the power supply, and the other end is connected to the collector of Q16 and the LOCAL_WAKE signal node. When the CP signal is input, the CP_IN signal generates a level transition; after being unidirectionally turned on by the switching diode D9, the signal passes through the RC delay filter circuit composed of resistor R110 and capacitor C63 connected in series; the signal after delay and filtering drives the base of NPN transistor Q16 through the base current limiting resistor R168. When the base voltage of Q16 reaches the conduction threshold, the transistor saturates and conducts, pulling the LOCAL_WAKE signal node, which was originally held at a high level by the pull-up resistor R120, down to a low level. The main control unit detects the downward transition of the LOCAL_WAKE signal and controls the electric vehicle communication controller to exit the sleep state and power on.

[0031] like Figure 6 As shown, the DC-DC conversion circuit consists of a DC-DC conversion chip U3, filter capacitors C6, C8, and C9, a bootstrap capacitor C10, output filter capacitors C23, C24, C26, and C28, a soft-start capacitor C57, C58, C59, and C61, a resistor R60, a voltage divider resistor R68, a frequency setting resistor R69, a resistor R70, a voltage divider resistor R73, a current limiting resistor R74, a resistor R76, a voltage divider resistor R87, a power inductor L11, and a light-emitting diode D1. The DC-DC converter chip U3 includes pins 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16. Pin 2 of DC-DC converter chip U3 is connected to ground via parallel connection of filter capacitors C6, C8, and C9; pins 3, 10, and 11 of DC-DC converter chip U3 are connected to bootstrap capacitor C10; pins 4, 9, and 13 of DC-DC converter chip U3 are grounded; pin 5 of DC-DC converter chip U3 is connected to voltage divider resistor R68 and the input signal; pin 7 of DC-DC converter chip U3 is connected to voltage divider resistor R73; pin 8 of DC-DC converter chip U3 is connected to ground via filter capacitor C61; pin 12 of DC-DC converter chip U3 is connected to ground via soft-start capacitor C57; pins 3, 9, and 11 of DC-DC converter chip U3 are connected to ground via parallel connection of filter capacitors C6, C8, and C9; pins 3, 9, and 11 of DC-DC converter chip U3 are connected to bootstrap capacitor C10; pins 4, 9, and 13 of DC-DC converter chip U3 are grounded; pin 5 of DC-DC converter chip U3 is connected to voltage divider resistor R68 and the input signal; pin 7 of DC-DC converter chip U3 is connected to voltage divider resistor R73; pin 8 of DC-DC converter chip U3 is connected to ground via parallel connection of filter capacitor C61; pin 12 of DC-DC converter chip U3 is connected to ground via parallel connection of filter capacitor C61 and the input signal ... Pin 14 is connected to capacitor C59 and then grounded; pin 15 of DC-DC converter chip U3 is connected to a voltage divider network, which includes resistors R87 and R69; pin 16 of DC-DC converter chip U3 is connected to resistor R76 and then grounded; one end of filter capacitor C58 is connected to the voltage divider network, and the other end is grounded; output filter capacitors C23, C24, C26, and C28 are connected in parallel, one end of which is connected to resistor R70 and LED D1, and the other end is grounded; the other end of LED D1 is connected to current-limiting resistor R74 and then grounded; one end of resistor R60 is connected to output terminal E1_12V-A, and the other end is connected to output terminal E1_12V; This wide-input DC-DC converter circuit uses a switching power supply chip at its core to convert a wide range of battery input voltages into a stable 12V output voltage. The circuit includes an input filter network composed of parallel multi-capacitors connected to the chip's voltage input pin for wide-band noise filtering and instantaneous high-current supply; an LC filter network composed of a power inductor and an output capacitor connected to the chip's switching node pin for smoothing high-frequency pulse voltages into DC voltage; a feedback network composed of voltage divider resistors connected to the chip's feedback pin for precise setting and stabilization of the output voltage; and a soft-start capacitor connected to the chip's soft-start pin to control the output voltage rise rate and suppress startup inrush current.

[0032] The present invention provides another technical solution, wherein the switching power supply chip is connected to a power status indicator circuit; the indicator circuit includes a power good indicator pin, which is an open-drain output and is connected to the output voltage through a pull-up resistor; the indicator circuit also includes a series branch of an LED and a current-limiting resistor, which is connected in parallel between the output voltage and ground; when the output voltage is established and stabilized, the power good indicator pin becomes a high-impedance state, its pull-up voltage is effective, and the LED is lit to indicate that the power supply is working normally.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An anti-interference control method for a communication controller applied to electric vehicles, characterized in that: The method includes: Based on the charging mode control relay, the connection path of the CP signal is switched. The default initial state is DC fast charging mode. When DC fast charging mode is detected, the relay is controlled to be energized, so that the CP signal is connected to the electric vehicle communication controller through the normally open contact of the relay and physically disconnected from the on-board charger. When AC slow charging mode is detected, the relay is controlled to be de-energized, and the CP signal is switched to the on-board charger. The system is equipped with a gun-activated wake-up circuit, a key-activated wake-up circuit, and a CP signal-activated wake-up circuit. Each of the wake-up circuits is provided with a unidirectional diode and an RC delay filter circuit, and the outputs of the three wake-up circuits are connected in parallel to the local wake-up signal node. The wide-range voltage provided by the electric vehicle battery is converted and stabilized to 12V through a wide-voltage input DC-DC conversion circuit to power the electric vehicle communication controller and its load. The main control unit continuously monitors the level status of the local wake-up signal node. When any of the wake-up circuits is triggered and causes the local wake-up signal node to generate a valid level transition, the electric vehicle communication controller is controlled to exit the sleep state and power on to start.

2. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 1, characterized in that: The connection path for the relay switching CP signal based on the charging mode control includes: The microcontroller outputs a CP switch control signal to the relay drive circuit, which includes a base current limiting resistor, an NPN transistor, and a freewheeling diode connected in parallel across the relay coil. The freewheeling diode is connected in reverse parallel across the relay coil to discharge the reverse induced electromotive force when the relay coil is de-energized. When the DC fast charging mode is detected, the CP switch control signal is high, which controls the NPN transistor to conduct, energizes the relay coil, and the normally open contact of the relay is energized. The CP signal of the charging interface is connected to the electric vehicle communication controller through the normally open contact of the relay. When the AC slow charging mode is detected, the CP switch control signal is low, which controls the NPN transistor to be cut off, de-energizing the relay coil, opening the normally open contact of the relay, and switching the CP signal of the charging interface to the on-board charger.

3. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 1, characterized in that: The plug-in wake-up circuit includes: When the charging gun is inserted, the charging gun wake-up signal changes from low to high. The charging gun wake-up signal is unidirectionally conducted through a switching diode. The charging gun wake-up signal is then filtered by an RC delay filter circuit, which consists of a resistor and a capacitor connected in series. One end of the resistor is connected to the cathode of the diode, and one end of the capacitor is grounded. The connection point of the resistor and capacitor serves as the filter output point. The charging gun wake-up signal at the filter output point drives the base of an NPN transistor through a base-limiting current resistor, causing the NPN transistor to saturate and conduct. The collector of the NPN transistor pulls the local wake-up signal node from high to low, generating a wake-up signal.

4. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 1, characterized in that: The key wake-up circuit includes: When the ignition switch is turned on, the key wake-up signal changes from low to high level, is unidirectionally turned on by the switching diode, and is then filtered by an RC delay filter circuit. The RC delay filter circuit is connected in series with a resistor and a capacitor. The key wake-up signal at the filtered output point drives the base of the NPN transistor through the base current limiting resistor, causing the NPN transistor to saturate and turn on, pulling the local wake-up signal node from high to low level, thus generating a wake-up signal.

5. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 1, characterized in that: The CP signal wake-up circuit includes: When the CP signal is input, the CP wake-up signal generates a level transition, which is unidirectionally turned on by the switching diode, and then the CP wake-up signal is RC delayed and filtered by the RC delay filter circuit. The RC delay filter circuit is connected in series with a resistor and a capacitor. The CP wake-up signal at the filtered output point drives the base of the NPN transistor through the base current limiting resistor, causing the NPN transistor to saturate and turn on, pulling the local wake-up signal node from high level to low level, thus generating a wake-up signal.

6. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 1, characterized in that: The wide-input DC-DC converter circuit converts a wide range of input voltages from the battery into a stable 12V output voltage, including: The wide-range voltage output from the electric vehicle battery is input into the DC-DC converter chip and filtered to remove wide-band noise and provide instantaneous high current. The filtering process includes a parallel input filter network, which includes multiple capacitive capacitors. The DC-DC converter chip is triggered to enter the working state by an enable circuit; the enable circuit includes a resistor and a capacitor, and the input voltage is pulled up by the resistor to complete the power-on self-start. The switching frequency of the power switch of the DC-DC converter chip is set by an external resistor. Based on the periodic on and off of the switching frequency, the input voltage is converted into a high-frequency pulse voltage. During the conduction period of the power switch, a bootstrap circuit provides a drive level higher than the switching node voltage to the upper transistor inside the chip. The high-frequency pulse voltage is smoothed into a stable DC voltage through an LC filter network; at the same time, the DC voltage is sampled and output in real time through a feedback network and fed back to the switching power supply chip to dynamically adjust the switching duty cycle to maintain a stable output voltage. During startup, the soft-start circuit controls the rise rate of the output DC voltage to suppress the surge current generated at startup; the power status indicator circuit monitors the output DC voltage status and generates an indicator signal when the output DC voltage stabilizes.

7. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 6, characterized in that: The DC-DC conversion circuit has a power status indication circuit, which includes an open-drain output power good indication pin and a series branch of a light-emitting diode and a current-limiting resistor. Once the output DC voltage is stabilized, the power good indicator pin changes to a high impedance state, and the LED is lit.

8. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 1, characterized in that: The main control unit continuously monitors the level status of the local wake-up signal node through the input / output port; when the local wake-up signal node transitions from high level to low level, the main control unit recognizes it as a valid wake-up event; the main control unit controls the power management circuit to provide operating voltage to the electric vehicle communication controller; the main control unit sends a reset release signal to the electric vehicle communication controller, causing the electric vehicle communication controller to exit the sleep state and enter the normal operation mode.

9. The anti-interference control method for a communication controller applied to an electric vehicle according to claim 8, characterized in that: After the main control unit controls the electric vehicle communication controller to power on and start, it continues to monitor the level status of the local wake-up signal node. When all wake-up signals disappear and the local wake-up signal node returns to a high level and remains high for a preset duration, the main control unit controls the electric vehicle communication controller to enter a sleep state and cuts off the operating power of the electric vehicle communication controller.

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