A portable electric vehicle alternating current charging control device

Abstract

The application provides a portable electric automobile AC charging control device, which comprises a main control module with a built-in single-chip microcomputer and a power regulating module; the power regulating module comprises a conversion device for converting a Signal signal (a live wire in the socket or a suspended wire) on a specific AC socket into a 50Hz 50% duty cycle pulse signal or a 0V non-pulse conversion device; the 50Hz 50% duty cycle pulse signal output by the conversion device is input into the single-chip microcomputer in the main control module; the single-chip microcomputer detects the pulse signal through external interruption; if the pulse signal is continuously detected, the duty cycle of the PWM output control signal is controlled to be a first duty cycle corresponding to a first output power; if the pulse signal cannot be detected, the duty cycle of the PWM output control signal is controlled to be a second duty cycle corresponding to a second output power. The application provides an automatic power regulating module with the function of automatically regulating the output power, which meets the market demand.

Description

Technical Field

[0001] This invention relates to a portable AC charging control device for electric vehicles. Background Technology

[0002] As the new energy vehicle market enters a period of rapid growth, charging infrastructure for electric vehicles is also increasing. Electric vehicle AC charging control devices provide convenience for electric vehicle owners, allowing them to carry the device with them, plug and play, and charge their vehicles anytime and anywhere from the nearby AC power grid. Their charging efficiency, cost, and safety directly impact the promotion of electric vehicles.

[0003] Chinese Invention Patent Publication No. CN 106329687 B discloses a portable AC charging pile control circuit. This portable AC charging pile control circuit includes: a control module, a voltage-to-current conversion and leakage current detection module, a power switch circuit module, a charging control guidance circuit module, an auxiliary power supply module, and a mains socket; it also includes a control box with a current switching button; the mains socket receives mains power and outputs it from the mains power output terminal; the auxiliary power supply module connects to the mains power output terminal, converts the received mains power into stable DC power and outputs it from the auxiliary voltage output interface; the auxiliary power supply module connects to the voltage-to-current conversion and leakage current detection module, the control module, and the charging control guidance circuit module through the auxiliary voltage output interface; the mains power output terminal connects to the voltage conversion signal input interface of the voltage-to-current conversion and leakage current detection module. The system includes a current conversion signal input interface and a leakage current detection signal input interface. The voltage-current conversion and leakage current detection module is connected to the control module via a voltage sampling interface, a current sampling interface, and a leakage current detection interface. The power switch circuit module is equipped with a relay or contactor. The control module is connected to the relay or contactor via a power control interface and to the charging control guide circuit module via a PWM control interface. The PWM output interface of the charging control guide circuit module and the AC power output interface of the power switch circuit module are connected to the charging gun. The current switching button of the control box is connected to the control module via a switching control interface. After the charging gun is inserted into the charging gun guide port, the PWM generation interface of the control module defaults to sending a PWM with a duty cycle D of 21.67%, limiting the maximum output current of the charging pile to 13A. If the user connects to a 16A to 10A adapter through the mains socket and presses the current switching button of the control box, the PWM generation interface defaults to sending a PWM with a duty cycle D of 13.3%, limiting the maximum output current of the charging pile to 8A.

[0004] This portable AC charging station control circuit uses a current switching button on the control box to trigger the main control chip to output PWM with different duty cycles. This allows the 16A to 10A adapter to connect to either the 16A or 10A socket on the charging station, thus limiting the charging station's output current to no more than 13A or 8A, providing a safe and reliable charging current for electric vehicle users. Furthermore, the adapter allows for easy switching between 13A and 8A output current on the same charging station, offering both convenience and resource savings.

[0005] However, this method of controlling the current by manually pressing buttons is unreliable. It's possible for a 10A socket to be accidentally set to a 16A charging current. Ordinary AC socket cables may not be able to handle 16A, causing excessive heat in the connecting wires and potentially leading to fires or other safety hazards. Therefore, this non-fully automatic control method cannot adequately meet market needs. Summary of the Invention

[0006] This invention addresses the shortcomings of current AC charging control devices for electric vehicles, which fail to meet market demands, by providing a portable AC charging control device for electric vehicles. This portable AC charging control device includes an automatic power adjustment module capable of automatically adjusting the output power.

[0007] The technical solution for achieving the technical objective of this invention is: a portable AC charging control device for electric vehicles, comprising a main control module with a built-in microcontroller and a power adjustment module; the power adjustment module includes a conversion device that converts a signal (which can be connected to a live wire or left floating) on ​​a specific socket into a 50Hz 50% duty cycle pulse signal or a 0V no-pulse signal. The 50Hz 50% duty cycle pulse signal output by the conversion device is input to the microcontroller in the main control module. The microcontroller detects the pulse signal through an external interrupt. If a continuous pulse signal is detected, the duty cycle of the PWM output control signal is controlled to be the first duty cycle corresponding to the first output power. If no pulse signal is detected, the duty cycle of the PWM output control signal is controlled to be the second duty cycle corresponding to the second output power.

[0008] Furthermore, in the aforementioned portable electric vehicle AC charging control device: the conversion device includes diodes D14 and D17, resistors R49, R51, R58, R60, R52, and R53, optocoupler U15, and capacitor C27.

[0009] Connect resistors R49, R51, the two primary pins of optocoupler U15, R58, and R60 in sequence between the signal line and ground line of the AC socket; connect diode D17 between the two primary pins of optocoupler U15, and connect the P terminal of diode D17 to the common terminal of optocoupler U15 source output terminal and resistor R58.

[0010] On the secondary side of optocoupler U15, the working power supply is grounded through resistor R52 and two pins of the secondary side of optocoupler U15. The common terminal connected to resistor R52 and the collector of the secondary side of optocoupler U15 is connected to resistor R53 to form an output signal that is connected to the microcontroller.

[0011] Capacitor C27 is placed between the two pins of the secondary side of optocoupler U15.

[0012] Furthermore, in the aforementioned portable electric vehicle AC charging control device: the first duty cycle is 53.3%, corresponding to a first output power of 7000W; the second duty cycle is 21.6%, corresponding to a second output power of 3000W.

[0013] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes an AC detection module, which includes a leakage current detection circuit, a voltage detection circuit, and a current detection circuit.

[0014] The leakage current detection circuit includes a leakage current transformer L4 and a metering IC U14. The output L / N line passes through the ring of the leakage current transformer L4. The output of the leakage current transformer L4 is connected to the metering IC U14. The metering IC U14 amplifies the signal and then transmits it through the serial port to the corresponding input terminal of the microcontroller of the main control module to detect leakage current. The microcontroller determines whether there is leakage.

[0015] The voltage detection circuit includes voltage divider resistors R27, R17, R25, R26, R43, and R48 connected in series between the AC live wire IN-L and the AC neutral wire GND_1. The common terminal connected to resistors R43 and R48 outputs a sampling signal DB_VP, which is sampled by the metering ICU14. The sampled data is queried by the microcontroller of the main control module through the serial port. The data is analyzed, and if the AC overvoltage or undervoltage protection threshold is exceeded, the relay will be cut off to protect the charging.

[0016] The current detection circuit includes a current sensing resistor R55 connected in series with the neutral line. The metering IC U14 samples the differential voltage across the sensing resistor. The sampled data is queried by the microcontroller of the main control module via the serial port. The microcontroller then analyzes the voltage value to obtain the current value. When the current exceeds the current protection threshold, the microcontroller will disconnect the relay to protect the charging.

[0017] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes a live / neutral phase reversal detection and grounding detection module for detecting AC live / neutral wire connection errors and grounding wire disconnection faults.

[0018] The aforementioned live wire / neutral wire phase reversal detection and ungrounded wire detection module includes an optocoupler U12, a diode D13, a transistor Q3, a capacitor C54, and resistors R86, R88, R96, R95, R90, R91, R92, R93, and R87.

[0019] On the primary side of optocoupler U12, the AC live wire IN-L is connected to the AC ground wire via diode D13, resistors R86 and R88, the two pins of the primary side of optocoupler U12, resistors R96 and R95; the P terminal of diode D13 is connected to the live wire IN-L.

[0020] On the secondary side of optocoupler U12, the collector is connected to the operating power supply (V3.3D), the emitter is grounded (DGND) through resistor R92, and resistor R91 is connected to the base of transistor Q3. The collector of transistor Q3 is connected to the operating power supply (V3.3D) through resistor R87. The output detection signal (AC-E_Detect) is connected to the corresponding port of the microcontroller of the main control module through resistor R90. The emitter is grounded, and resistor R93 and capacitor C54 are connected between the base of transistor Q3 and ground.

[0021] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes a control circuit that controls the activation or deactivation of a relay when the AC phase is 0. This control circuit includes a zero-crossing detection circuit. The zero-crossing detection circuit includes an optocoupler U13, a diode D16, a capacitor D19, a capacitor C59, and resistors R98, R100, R106, R105, R101, and R102.

[0022] On the primary side of optocoupler U13: a diode D16, a resistor R98, a resistor R100, a diode D19, a resistor R106, and a resistor R105 are connected in series between the AC live wire IN-L and the AC neutral wire N. The P terminal of diode D16 is connected to the AC live wire IN-L, and the P terminal of diode D19 is connected to the resistor R106. The two ends of the LED on the primary side of optocoupler U13 are connected to the two ends of diode D19, and the N terminal of the LED is connected to the resistor R106.

[0023] On the secondary side of optocoupler U13: the collector of optocoupler U13 is connected to the working power supply (V3.3D) through resistor R101, and the zero-crossing detection signal AC_PLUS is output through resistor R102 and connected to the microcontroller of the main control module; the emitter of optocoupler U13 is grounded, and capacitor C59 is connected between the two pins of the secondary side of optocoupler U13.

[0024] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes a relay control module, comprising a live wire IN-L relay control circuit and a neutral wire N relay control circuit with identical structures.

[0025] The relay control circuit includes transistor Q1, resistors R89 and R94, capacitor C53, and diode D15;

[0026] The control power supply (VCC_R) is connected to one end of the relay coil, and the other end of the relay coil is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded, and the base of transistor Q1 is connected to the control signal (RELAY) generated by the microcontroller of the main control module through the current limiting resistor R94. Resistor R89 ​​and capacitor C53 are both placed between the base and emitter of transistor Q1.

[0027] Diode D15 is positioned across the relay coil, with the N-terminal of diode D15 connected to the control power supply (VCC_R).

[0028] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes a pulse output circuit; the pulse output circuit includes operational amplifier U1A, operational amplifier U1B, resistors R2, R5, R7, R4, R3, inductor L1, and Zener diode D1.

[0029] The pulse signal PWM1 generated by the microcontroller of the main control module is connected to the non-inverting input of the operational amplifier U1A via resistor R2. The +12V voltage signal is divided by resistors R5 and R7 and then connected to the non-inverting input of the operational amplifier U1A. At the output of the operational amplifier U1A, a pulse signal with a voltage of -12V to +12V with the same frequency as the pulse signal PWM1 is generated and connected to the input of the follower composed of operational amplifier U1B and resistor R1. The output of the follower is connected to one end of inductor L1 via current limiting resistor R3. The other end of inductor L1 is grounded through Zener diode D1. The common terminal of the other end of inductor L1 and the N terminal of Zener diode D1 forms the output pulse signal (CP) which is connected to the interface of the charging electric vehicle.

[0030] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes a pulse sampling module; the pulse sampling module includes a diode D3, an operational amplifier U2A, resistors R9, R14, R11, R12, R13, R8, R10, and capacitors C5, C6, C4.

[0031] CP_IN is grounded via diode D3, resistor R9, and resistor R14 in sequence. The common terminal of resistors R9 and R14 is connected to a follower consisting of operational amplifier U2A and resistor R8 via resistors R11, R12, and R13. The output of the follower is connected to resistor R10 to form the output signal CP_AD_IN, which is then connected to the corresponding input port of the microcontroller in the main control module. Capacitor C5 is connected between the common terminal of resistors R11 and R12 and ground, capacitor C6 is connected between the common terminal of resistors R12 and R13 and ground, and capacitor C4 is connected between the output signal CP_AD_IN and ground.

[0032] Furthermore, the aforementioned portable electric vehicle AC charging control device also includes a sampling module for sampling the temperature of the charging device. The output of the temperature sampling module is connected to the corresponding interface of the microcontroller of the main control module. The microcontroller judges the temperature output by the temperature sampling module, and if it is higher than the threshold, it controls the relay to disconnect and stop charging.

[0033] This invention provides an automatic power adjustment module capable of automatically adjusting output power, meeting market needs.

[0034] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] Appendix Figure 1 This is a schematic diagram of the present invention.

[0036] Appendix Figure 2 This is a circuit diagram of the power regulation module in Embodiment 1 of the present invention.

[0037] Appendix Figure 3 This is a circuit schematic diagram of the AC detection module in Embodiment 1 of the present invention.

[0038] Appendix Figure 4 This is a circuit diagram of the live wire and neutral wire phase mismatch detection and ungrounded wire detection module in Embodiment 1 of the present invention.

[0039] Appendix Figure 5 This is a schematic diagram of the zero-crossing detection circuit in Embodiment 1 of the present invention.

[0040] Appendix Figure 6 This is a circuit diagram of the relay control module in Embodiment 1 of the present invention.

[0041] Appendix Figure 7 This is a schematic diagram of the pulse output circuit in Embodiment 1 of the present invention.

[0042] Appendix Figure 8 This is a pulse sampling circuit diagram of Embodiment 1 of the present invention. Detailed Implementation

[0043] like Figure 1 As shown, the purpose of this embodiment is to solve the problems of existing charging boxes, such as limited technology, non-adjustable power, high cost, and charging safety. It provides a low-cost, safe, and reliable adjustable power charging control box solution that meets national standards and intelligently allocates power based on vehicle needs, grid limitations, and set charging strategies. This ensures both full utilization of the charging control box and charging safety, while also meeting customers' needs for improved charging efficiency.

[0044] This embodiment describes a portable AC charging control device for electric vehicles, such as... Figure 1 As shown, it includes a microcontroller main control module, a power regulation module, an input detection module, a live / neutral phase reversal and ungrounded detection module, a relay control module, a CP signal pulse output and sampling module, and a temperature sampling module.

[0045] Power regulation module such as Figure 2 As shown, the device includes a converter that converts a socket signal into a 50Hz pulse signal with a 50% duty cycle. The signal can be connected to a live wire or left floating in the socket. The 50Hz pulse signal with a 50% duty cycle output by the converter is input to the microcontroller in the main control module. The microcontroller detects the pulse signal through an external interrupt. If a pulse signal is continuously detected, the microcontroller controls the duty cycle of the PWM of the output control signal CP to be the first duty cycle corresponding to the first output power. If no pulse signal is detected, the microcontroller controls the duty cycle of the PWM of the output control signal CP to be the second duty cycle corresponding to the second output power.

[0046] Conversion device such as Figure 2 As shown, it includes diodes D14 and D17, resistors R49, R51, R58, R60, R52, R53, optocoupler U15, and capacitor C27.

[0047] Connect resistors R49, R51, the two primary pins of optocoupler U15, R58, and R60 sequentially between the signal line (Signal) and ground line (N) of the AC socket. Connect diode D17 between the two primary pins of optocoupler U15, with the P-terminal of diode D17 connected to the common terminal of the source output of optocoupler U15 and resistor R58. On the secondary side of optocoupler U15, the operating power supply V3.3D is grounded through resistor R52 and the two secondary pins of optocoupler U15. Connect resistor R53 to the common terminal of resistor R52 and the collector of the secondary side of optocoupler U15 to form the output signal sig, which is connected to the microcontroller. Place capacitor C27 between the two secondary pins of optocoupler U15.

[0048] like Figure 2As shown: The Signal terminal is connected to the socket's signal line, N is connected to the neutral line, and sig is connected to the microcontroller's detection pin. For high-power sockets, the SIGNAL terminal will have a 220V / 50Hz signal, the same as the live wire. After passing through diode D14, the negative half-cycle is filtered out. After passing through the optocoupler, the positive half-cycle will turn on the LED of optocoupler U15. At the sig pin of resistor R53 on the other end of optocoupler U15, a 50Hz pulse with approximately 50% duty cycle is generated. The microcontroller detects the sig pin via an external interrupt. If a continuous pulse signal is detected, the PWM output of the CP is controlled to have a 53.3% duty cycle, equivalent to 32A current or 7000W power. If no pulse signal is detected, the PWM output of the CP is controlled to have a 21.6% duty cycle, equivalent to 13A current or 3000W power. This is used to adjust the output power.

[0049] AC detection module such as Figure 3 As shown, the AC detection module includes a leakage current detection circuit, a voltage detection circuit, and a current detection circuit.

[0050] The leakage current detection circuit includes a leakage current transformer L4 and a metering IC U14. The output L / N lines pass through the loop of the leakage current transformer L4. The output of the leakage current transformer L4 is connected to the metering IC U14. The metering IC U14 amplifies the signal and transmits it via serial port to the corresponding input terminal of the microcontroller in the main control module to detect leakage current. The microcontroller determines whether there is a leakage current. The leakage current is detected by the leakage current transformer L4. The output L / N lines pass through the loop of the leakage current transformer. When there is no leakage, the currents in the L / N lines are equal in magnitude but opposite in direction, and there is no induced voltage in the leakage current transformer. When there is a leakage, the currents in the L / N lines in the loop are no longer equal. Therefore, a voltage signal is generated in the transformer based on electromagnetic induction. This signal is then connected to the U14 chip, which amplifies the signal and transmits it to the microcontroller via serial port. Once the received leakage current exceeds the threshold, the microcontroller disconnects the relay for protection.

[0051] The voltage detection circuit includes voltage divider resistors R27, R17, R25, R26, R43, and R48 connected in series between the AC live wire IN-L and the AC neutral wire GND_1. A sampling signal DB_VP is output from the common terminal of resistors R43 and R48, which is sampled by the metering IC U14. The sampled data is queried by the microcontroller of the main control module via a serial port. The data is analyzed, and if the AC overvoltage or undervoltage protection threshold is exceeded, the relay will be cut off to protect the charging circuit. The current detection circuit includes a current sensing resistor R55 connected in series on the neutral wire. The metering IC U14 BL0939 samples the differential voltage across the sensing resistor. The sampled data is queried by the microcontroller of the main control module via a serial port. The microcontroller then analyzes this voltage value to obtain the current value. If the current protection threshold is exceeded, the microcontroller will cut off the relay to protect the charging circuit. Voltage detection is achieved by dividing the AC current using resistors R27, R17, R25, R26, R43, and R48. IN-L is connected to the AC live wire, and GND_1 is connected to the AC neutral wire. The voltage at point DB_VP is equal to the AC input voltage multiplied by the value of R48 / (R27+R17+R25+R26+R43+R48), making the voltage at point DB_VP relatively small, which is beneficial for detection by the U14 chip. Finally, the voltage at point DB_VP, connected to pin 7 of the U14 chip, is sampled. The sampled data is then queried by the microcontroller via the serial port. After data analysis, if the AC overvoltage or undervoltage protection threshold is exceeded, the microcontroller will disconnect the relay to protect the charging circuit.

[0052] A module for detecting incorrect live / neutral wire connections and unconnected ground wires in AC circuits; such as... Figure 4 As shown: The live wire / neutral wire phase reversal detection and ungrounded wire detection module includes optocoupler U12, diode D13, transistor Q3, capacitor C54, and resistors R86, R88, R96, R95, R90, R91, R92, R93, and R87. On the primary side of optocoupler U12, the AC live wire IN-L is connected to the AC ground wire via diode D13, resistors R86 and R88, the two pins of the primary side of optocoupler U12, and resistors R96 and R95. The P terminal of diode D13... Connect the live wire IN-L; on the secondary side of optocoupler U12, the collector is connected to the operating power supply V3.3D, the emitter is grounded to DGND through resistor R92, resistor R91 is connected to the base of transistor Q3, the collector of transistor Q3 is connected to the operating power supply V3.3D through resistor R87, and the output detection signal is connected to AC-E_Detect through resistor R90, which is connected to the corresponding port of the microcontroller in the main control module; the emitter is grounded, and resistor R93 and capacitor C54 are connected between the base of transistor Q3 and ground. Figure 4As shown: Current detection is achieved by connecting a current-sensing resistor R55 in series on the neutral wire. According to Ohm's law I=U / R, the current flowing through R55 is equal to the voltage across R55 divided by the resistance of R55. This circuit connects the resistors across R55, through resistors R50 and R57, to the U14 chip. The U14 chip samples the differential voltage across R55, and this data is sent to the microcontroller via a serial port. The microcontroller then analyzes this voltage value to determine the current value. When the current exceeds the protection threshold, the microcontroller will disconnect the relay to protect the charging circuit. This circuit can detect AC faults such as incorrect live / neutral wire connection and missing ground wire. Figure 4 In the circuit diagram shown, IN-L is connected to the AC live wire, and the right end of R95 is connected to the AC ground wire. AC-E_Detcte is connected to the microcontroller's detection pin.

[0053] When the input terminals are correctly connected to the live wire, neutral wire, and ground, the LED of optocoupler U12 only conducts during the positive half-cycle and not during the negative half-cycle. Therefore, a square wave with a duty cycle of approximately 50% and a frequency of 50Hz is generated at pin 3 of optocoupler U12 connected to resistor R91. Connecting R91 to transistor Q3 allows for a better square wave waveform to be obtained at the AC-E-Detect pin, facilitating microcontroller detection. When the microcontroller detects a square wave signal of approximately 50Hz at the AC-E_Detect pin, it determines that the connection is correct.

[0054] When the live wire and neutral wire are reversed or there is no grounding wire, IN-L is the neutral wire, and the potential difference between it and the ground is almost 0. The U12 optocoupler will not conduct. If the microcontroller detects that the voltage of the AC-E_Detcte pin is continuously low, it will determine that the live wire and neutral wire are connected incorrectly or there is no grounding wire.

[0055] In this embodiment, this detection can be achieved with only one metering IC U14, one leakage current transformer, and some resistors and capacitors, resulting in very low cost. The metering IC U14 used here is model BL0939. BL0939 is a built-in clock-based, calibration-free energy metering chip suitable for applications such as single-phase multi-function energy meters, smart sockets, smart home appliances, and electric bicycle charging stations, offering high cost-effectiveness. BL0939 integrates three high-precision Sigma-Delta ADCs, capable of simultaneously measuring two current channels and one voltage channel. This chip is commonly used to measure output power. In this embodiment, it measures the current of the leakage current transformer to determine if there is leakage. BL0939 can measure parameters such as current, voltage RMS values, active power, and active energy, and can output fast current RMS values ​​(for leakage monitoring or overcurrent protection), as well as temperature sensors, waveform output, and other functions. It outputs data through a UART / SPI interface, fully meeting the needs of smart sockets, smart home appliances, single-phase multi-function energy meters, electric bicycle charging stations, and electricity information big data collection. The BL0939 features a patented anti-creep design, which, combined with a well-designed external hardware, ensures that noise power is not counted as an energy pulse when there is no current.

[0056] In this embodiment, the control circuit that controls the relay's activation or deactivation when the AC phase is 0 includes a zero-crossing detection circuit; the zero-crossing detection circuit is as follows: Figure 5 As shown, the system includes optocoupler U13, diodes D16 and D19, capacitor C59, and resistors R98, R100, R106, R105, R101, and R102. On the primary side of optocoupler U13, between the AC live wire IN-L and the AC neutral wire N, diode D16, resistors R98, R100, diode D19, resistors R106 and R105 are connected in series. The P-terminal of diode D16 is connected to the AC live wire IN-L, and the P-terminal of diode D19 is connected to... The primary side of optocoupler U13 is connected to the two ends of diode D19, with the N-terminal of the LED connected to resistor R106. On the secondary side of optocoupler U13: the collector of optocoupler U13 is connected to the operating power supply V3.3D through resistor R101, and the zero-crossing detection signal AC_PLUS is output through resistor R102 and connected to the microcontroller of the main control module. The emitter of optocoupler U13 is grounded, and capacitor C59 is connected between the two pins of the secondary side of optocoupler U13. The zero-crossing circuit is shown below: IN-L is connected to the AC live wire, and N is connected to the AC neutral wire. AC_PLUS is connected to the microcontroller's detection pin.

[0057] When the terminal connections are correct, the optocoupler U13 between the IN-L and N lines will turn on its LED once every half AC cycle, generating a square wave signal with approximately 50% duty cycle and 50Hz at the AC_PLUS position on the other end of the optocoupler. The microcontroller is configured to use the AC_PLUS detection pin as an external interrupt detection pin, triggered by the rising and falling edges. This pin is used to detect the rising and falling edges of AC_PLUS; the interrupt occurs at the instant the AC signal crosses zero.

[0058] The purpose of a zero-crossing detection circuit is to control the relay to engage or disengage when the AC phase is 0. This effectively reduces the instantaneous current at the relay's engagement point and improves the relay's lifespan.

[0059] Relay control module such as Figure 6 As shown, it includes a live wire IN-L relay control circuit and a neutral wire N relay control circuit with identical structures. The relay control circuit includes a transistor Q1, resistors R89 and R94, a capacitor C53, and a diode D15. The control power supply VCC_R is connected to one end of the relay coil, and the other end of the relay coil is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded, and the base of the transistor is connected to the control signal RELAY generated by the microcontroller of the main control module through the current-limiting resistor R94. Resistor R89 ​​and capacitor C53 are both placed between the base and emitter of transistor Q1. Diode D15 is placed across the relay coil, and the N terminal of diode D15 is connected to the control power supply VCC_R.

[0060] Relay control module such as Figure 6 As shown, it consists of two identical circuits that control the live wire relay and the neutral wire relay respectively. The signal RELAY is connected to the microcontroller pin, IN-L is connected to the input AC live wire, OUT-L is connected to the output live wire, N is connected to the input AC neutral wire, OUT-N is connected to the output neutral wire, VCC is connected to the 12V power supply, and DGND is connected to the ground of VCC.

[0061] Relays K1 and K2 are normally open relays. When the microcontroller pin is given a high level at the RELAY terminal, the collector and emitter terminals of transistors Q1 / Q2 are turned on, and relays K1 / K2 are energized. When the microcontroller pin is given a low level at the RELAY terminal, Q1 / Q2 are not turned on, and relays K1 / K2 are de-energized.

[0062] In this embodiment, an emergency stop switch is also provided, such as Figure 6 CON1 is an emergency stop switch installed in the relay coil power supply circuit. When an emergency stop is required, pressing the emergency stop switch will disconnect the two ends of CON1, thereby cutting off the VCC power supply to the relay, causing the relay to spring open and achieving the purpose of emergency protection.

[0063] In this embodiment, a pulse output circuit and a pulse detection circuit are also included. The pulse output circuit is as follows: Figure 7 As shown; the pulse output circuit includes operational amplifier U1A, operational amplifier U1B, resistors R2, R5, R7, R4, R3, inductor L1, and Zener diode D1; the pulse signal PWM1 generated by the microcontroller of the main control module is connected to the non-inverting input of operational amplifier U1A via resistor R2. The +12V voltage signal is divided by resistors R5 and R7 and then connected to the non-inverting input of operational amplifier U1A. A pulse signal with a voltage of -12V to +12V with the same frequency as the pulse signal PWM1 is formed at the output of operational amplifier U1A and connected to the input of a follower composed of operational amplifier U1B and resistor R1. The output of the follower is connected to one end of inductor L1 via current-limiting resistor R3. The other end of inductor L1 is grounded through Zener diode D1. The common terminal of the other end of inductor L1 and the N-terminal of Zener diode D1 forms the output pulse signal CP, which is connected to the interface of the charging electric vehicle.

[0064] Pulse sampling module such as Figure 8 As shown: Includes diode D3, operational amplifier U2A, resistors R9, R14, R11, R12, R13, R8, R10, and capacitors C5, C6, C4. CP_IN is grounded sequentially via diode D3, resistor R9, and resistor R14. The common terminal of resistors R9 and R14 is connected to a follower consisting of operational amplifier U2A and resistor R8 via resistors R11, R12, and R13. The output of the follower is connected to resistor R10 to form the output signal CP_AD_IN, which is then connected to the corresponding input port of the microcontroller in the main control module. Capacitor C5 is connected between the common terminal of resistors R11 and R12 and ground; capacitor C6 is connected between the common terminal of resistors R12 and R13 and ground; and capacitor C4 is connected between the output signal CP_AD_IN and ground.

[0065] like Figure 7 and Figure 8 As shown, pin PWM1 is connected to a microcontroller pin for outputting PWM signals. 12V+ is connected to the +12V power supply, 12V- is connected to the -12V power supply, and DGND is grounded. Figure 7 CP_IN and Figure 8 D3 is connected for sampling, and CP is connected to the CP terminal and then to the vehicle interface. CP_AD_IN connects the CP signal to the microcontroller's sampling pin through an inductor L1.

[0066] The microcontroller outputs a PWM pulse to the PWM1 output. Since the output voltage of the open-loop op-amp is equal to the difference between the two input pins multiplied by the open-loop differential gain Aog, when Aog approaches infinity, even a small voltage difference will cause the output voltage to approach saturation. Therefore, after passing through U1A, PWM1 becomes a pulse with the same frequency and a voltage range of -12V to +12V. This pulse is then passed through a follower to increase the input impedance and decrease the output impedance, forming the CP pulse signal. This pulse formation method results in high amplitude accuracy of the output CP pulse waveform and high resolution of the output frequency and duty cycle.

[0067] The CP_IN pin filters out the negative voltage through diode D3, and then passes through resistors R9 and R14 to divide the voltage, ensuring that the voltage does not exceed the maximum voltage that the microcontroller can withstand. The PWM signal then passes through two stages of RC follower U2A to become a stable voltage signal, and then passes through R10 to enter the microcontroller pin. The microcontroller pin detects CP_AD_IN to determine which stage of charging it belongs to and controls the relay to engage.

[0068] In addition, it also includes a sampling module that samples the temperature of the charging device. The output of the temperature sampling module is connected to the corresponding interface of the microcontroller of the main control module. The microcontroller judges the temperature output by the temperature sampling module. If it is higher than the threshold, it controls the relay to disconnect and stop charging.

Claims

1. A portable AC charging control device for electric vehicles, comprising a main control module with a built-in microcontroller and a power regulation module; characterized in that: The power regulation module includes a conversion device that converts a signal from an AC socket into a 50Hz 50% duty cycle pulse signal or a 0V no-pulse signal. The 50Hz 50% duty cycle pulse signal output by the conversion device is input to the microcontroller in the main control module. The microcontroller detects the pulse signal through an external interrupt. If a pulse signal is continuously detected, the duty cycle of the PWM of the output control signal (CP) is controlled to be the first duty cycle corresponding to the first output power. If no pulse signal is detected, the duty cycle of the PWM of the output control signal (CP) is controlled to be the second duty cycle corresponding to the second output power. The conversion device includes diodes D14 and D17, resistors R49, R51, R58, R60, R52, and R53, optocoupler U15, and capacitor C27. Connect resistors R49, R51, the two primary pins of optocoupler U15, R58, and R60 in sequence between the signal line (Signal) and ground line (N) of the AC socket; connect diode D17 between the two primary pins of optocoupler U15, and connect the P terminal of diode D17 to the common terminal of optocoupler U15 source output terminal and resistor R58. On the secondary side of optocoupler U15, the working power supply (V3.3D) is grounded through resistor R52 and two pins of the secondary side of optocoupler U15. The common terminal of resistor R52 connected to the collector of the secondary side of optocoupler U15 is connected to resistor R53 to form an output signal (sig) which is connected to the microcontroller. Capacitor C27 is placed between the two pins of the secondary side of optocoupler U15.

2. The portable electric vehicle AC charging control device according to claim 1, characterized in that: The first duty cycle is 53.3%, and the corresponding first output power is 7000W. The second duty cycle is 21.6%, which corresponds to a second output power of 3000W.

3. The portable AC charging control device for electric vehicles according to claim 1 or 2, characterized in that: It also includes an AC detection module, which includes a leakage current detection circuit, a voltage detection circuit, and a current detection circuit. The leakage current detection circuit includes a leakage current transformer L4 and a metering IC U14. The output L / N line passes through the ring of the leakage current transformer L4. The output of the leakage current transformer L4 is connected to the metering IC U14. The metering IC U14 amplifies the signal and then transmits it through the serial port to the corresponding input terminal of the microcontroller of the main control module to detect leakage current. The microcontroller determines whether there is leakage. The voltage detection circuit includes voltage divider resistors R27, R17, R25, R26, R43, and R48 connected in series between the AC live wire IN-L and the AC neutral wire GND_1. The common terminal connected to resistors R43 and R48 outputs a sampling signal DB_VP, which is sampled by the metering IC U14. The sampled data is queried by the microcontroller of the main control module through the serial port. The data is analyzed, and if the AC overvoltage or undervoltage protection threshold is exceeded, the relay will be cut off to protect the charging. The current detection circuit includes a current sensing resistor R55 connected in series with the neutral line. The metering IC U14 samples the differential voltage across the sensing resistor. The sampled data is queried by the microcontroller of the main control module via the serial port. The microcontroller then analyzes the voltage value to obtain the current value. When the current exceeds the current protection threshold, the microcontroller will disconnect the relay to protect the charging.

4. The portable AC charging control device for electric vehicles according to claim 1 or 2, characterized in that: It also includes modules for detecting live and neutral wire misconnection faults and unconnected ground wire faults in AC circuits; The aforementioned live wire / neutral wire phase reversal detection and ungrounded wire detection module includes an optocoupler U12, a diode D13, a transistor Q3, a capacitor C54, and resistors R86, R88, R96, R95, R90, R91, R92, R93, and R87. On the primary side of optocoupler U12, the AC live wire IN-L is connected to the AC ground wire via diode D13, resistors R86 and R88, the two pins of the primary side of optocoupler U12, resistors R96 and R95; the P terminal of diode D13 is connected to the live wire IN-L. On the secondary side of optocoupler U12, the collector is connected to the operating power supply (V3.3D), the emitter is grounded (DGND) through resistor R92, and resistor R91 is connected to the base of transistor Q3. The collector of transistor Q3 is connected to the operating power supply (V3.3D) through resistor R87. The detection signal (AC-E_Detect) is output through resistor R90 and connected to the corresponding port of the microcontroller of the main control module. The emitter is grounded, and resistor R93 and capacitor C54 are connected between the base of transistor Q3 and ground.

5. The portable AC charging control device for electric vehicles according to claim 1 or 2, characterized in that: It also includes a control circuit for controlling the activation or deactivation of a relay when the AC phase is 0. This control circuit includes a zero-crossing detection circuit. The zero-crossing detection circuit includes an optocoupler U13, a diode D16, a capacitor D19, a capacitor C59, and resistors R98, R100, R106, R105, R101, and R102. On the primary side of optocoupler U13: a diode D16, a resistor R98, a resistor R100, a diode D19, a resistor R106, and a resistor R105 are connected in series between the AC live wire IN-L and the AC neutral wire N. The P terminal of diode D16 is connected to the AC live wire IN-L, and the P terminal of diode D19 is connected to the resistor R106. The two ends of the LED on the primary side of optocoupler U13 are connected to the two ends of diode D19, and the N terminal of the LED is connected to the resistor R106. On the secondary side of optocoupler U13: the collector of optocoupler U13 is connected to the working power supply (V3.3D) through resistor R101, and the zero-crossing detection signal AC_PLUS is output through resistor R102 and connected to the microcontroller of the main control module; the emitter of optocoupler U13 is grounded, and capacitor C59 is connected between the two pins of the secondary side of optocoupler U13.

6. The portable AC charging control device for electric vehicles according to claim 1 or 2, characterized in that: It also includes a relay control module; including a live wire IN-L relay control circuit and a neutral wire N relay control circuit with the same structure; The relay control circuit includes transistor Q1, resistors R89 and R94, capacitor C53, and diode D15; The control power supply (VCC_R) is connected to one end of the relay coil, and the other end of the relay coil is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded, and the base of transistor Q1 is connected to the control signal (RELAY) generated by the microcontroller of the main control module through the current limiting resistor R94. Resistor R89 ​​and capacitor C53 are both placed between the base and emitter of transistor Q1. Diode D15 is positioned across the relay coil, with the N-terminal of diode D15 connected to the control power supply (VCC_R).

7. The portable AC charging control device for electric vehicles according to claim 1 or 2, characterized in that: It also includes a pulse output circuit; the pulse output circuit includes operational amplifier U1A, operational amplifier U1B, resistors R2, R5, R7, R4, R3, inductor L1, and Zener diode D1; The pulse signal PWM1 generated by the microcontroller of the main control module is connected to the non-inverting input of the operational amplifier U1A via resistor R2. The +12V voltage signal is divided by resistors R5 and R7 and then connected to the non-inverting input of the operational amplifier U1A. At the output of the operational amplifier U1A, a pulse signal with a voltage of -12V to +12V with the same frequency as the pulse signal PWM1 is generated and connected to the input of the follower composed of operational amplifier U1B and resistor R1. The output of the follower is connected to one end of inductor L1 via current limiting resistor R3. The other end of inductor L1 is grounded through Zener diode D1. The common terminal of the other end of inductor L1 and the N terminal of Zener diode D1 forms the output pulse signal (CP) which is connected to the interface of the charging electric vehicle.

8. The portable AC charging control device for electric vehicles according to claim 7, characterized in that: It also includes a pulse sampling module; the pulse sampling module includes diode D3, operational amplifier U2A, resistors R9, R14, R11, R12, R13, R8, R10 and capacitors C5, C6, C4; CP_IN is grounded via diode D3, resistor R9, and resistor R14 in sequence. The common terminal of resistors R9 and R14 is connected to a follower consisting of operational amplifier U2A and resistor R8 via resistors R11, R12, and R13. The output of the follower is connected to resistor R10 to form the output signal CP_AD_IN, which is then connected to the corresponding input port of the microcontroller in the main control module. Capacitor C5 is connected between the common terminal of resistors R11 and R12 and ground, capacitor C6 is connected between the common terminal of resistors R12 and R13 and ground, and capacitor C4 is connected between the output signal CP_AD_IN and ground.

9. The portable AC charging control device for electric vehicles according to claim 1 or 2, characterized in that: It also includes a sampling module for sampling the temperature of the charging device. The output of the temperature sampling module is connected to the corresponding interface of the microcontroller of the main control module. The microcontroller judges the temperature output by the temperature sampling module. If it is higher than the threshold, it controls the relay to disconnect and stop charging.

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