A charging pile circuit based on a single power supply

Abstract

The present invention provides a charging pile circuit based on a single power supply, which relates to the technical field of charging piles and includes a PE signal terminal, a CP signal terminal, a CC signal terminal, a PWM generator, a first triode, a MOS tube, a first emitter follower, a second emitter follower, a first signal isolator, and a second signal isolator. The first signal isolator and the second signal isolator are reversely connected in parallel. The present invention uses a PWM to generate a pulse wave to control the conduction of the MOS tube to generate a CP signal of plus and minus 12V. At the same time, regardless of whether the PE signal is plus 12V or 0V, the CC signal can be detected through the optocouplers connected in reverse parallel, reducing the circuit complexity and cost expenditure.

Description

Technical Field

[0001] The present invention relates to the technical field of charging piles, and particularly to a charging pile circuit based on a single power supply. Background Art

[0002] Today, with the popularization of electric vehicles and the increasing number of charging piles, as an indispensable key component in the charging process, the application scope of AC charging piles is also expanding day by day. And with the continuous popularization of in-vehicle OBCs, the application scenarios of AC charging piles have expanded from passenger cars to industrial vehicles, logistics vehicles, tour buses, cruise ships and other industries. Currently, the communication between existing AC charging piles and in-vehicle OBCs generally adopts a dual-power supply scheme to meet the requirement of ±12V for the CP signal of the in-vehicle OBC. However, the use of a dual-power supply will increase the design complexity, lead to an over-large circuit volume, an increase in PCB area, and an increase in cost. In addition, the dual-power supply may also reduce the reliability of the system. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, at least one embodiment of the present invention provides a charging pile circuit based on a single power supply, which generates a ±12V CP signal through a single power supply, reducing the circuit complexity and cost expenditure.

[0004] An embodiment of the present invention proposes a charging pile circuit based on a single power supply, including a PE signal terminal, a CP signal terminal, a CC signal terminal, a PWM generator, a first triode, a MOS transistor, a first emitter follower, a second emitter follower, a first signal isolator and a second signal isolator, and the first signal isolator and the second signal isolator are reversely connected in parallel;

[0005] The PWM generator is connected to the emitter of the first triode, the base of the first triode is connected to the power supply voltage through a first resistor, the collector of the first triode is connected to the power supply voltage through a second resistor and connected to the gate of the MOS transistor through a third resistor; the drain of the MOS transistor is connected to the power supply voltage through a fourth resistor, and the source of the MOS transistor is grounded;

[0006] The input end of the first emitter follower is respectively connected to the collector of the first triode, the second resistor and the third resistor, the output end of the first emitter follower is respectively connected to the cathode of the first signal isolator and the anode of the second signal isolator, and the anode of the first signal isolator and the cathode of the second signal isolator are respectively connected to the power supply voltage through a fifth resistor; the input end of the second emitter follower is respectively connected to the fourth resistor and the drain of the MOS transistor, and the output end of the second emitter follower is connected to the PE signal terminal;

[0007] The CP signal terminal is connected to the output end of the first emitter follower through a sixth resistor, and the CC signal terminal is respectively connected to the cathode of the first signal isolator and the anode of the second signal isolator through a seventh resistor.

[0008] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the first emitter follower includes a second triode and a third triode. The bases of the second triode and the third triode are both connected to the collector of the first triode, the second resistor, and the third resistor; the collector of the second triode is connected to the power supply voltage, and the collector of the third triode is grounded; the emitters of the second triode and the third triode are both connected to the sixth resistor, the anode of the first signal isolator, and the cathode of the second signal isolator.

[0009] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the second emitter follower includes a fourth triode and a fifth triode. The bases of the fourth triode and the fifth triode are both connected to the drain of the MOS transistor and the fourth resistor; the collector of the fourth triode is connected to the power supply voltage, and the collector of the fifth triode is grounded; the emitters of the fourth triode and the fifth triode are both connected to the PE signal terminal.

[0010] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, an eighth resistor is connected between the base and the source of the MOS transistor.

[0011] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the charging pile circuit further includes a first capacitor. One end of the first capacitor is respectively connected to the fifth resistor, the cathode of the first signal isolator, and the anode of the second signal isolator.

[0012] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, a voltage dividing and filtering circuit is connected to one end of the sixth resistor.

[0013] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the voltage dividing and filtering circuit includes a ninth resistor, a tenth resistor, and a second capacitor; one end of the ninth resistor is connected to the sixth resistor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and one end of the second capacitor, and the other ends of the tenth resistor and the second capacitor are grounded.

[0014] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the voltage dividing and filtering circuit further includes a first clamping diode and a second clamping diode. The negative electrode of the first clamping diode is respectively connected to the positive electrode of the second clamping diode, the ninth resistor, and the tenth resistor; the positive electrode of the first clamping diode is grounded, and the negative electrode of the second clamping diode is connected to the power supply voltage.

[0015] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the first signal isolator is an optocoupler.

[0016] Preferably, for a charging pile circuit based on a single power supply provided by the present invention, the second signal isolator is an optocoupler.

[0017] It can be seen that for a single - power charging pile circuit according to an embodiment of the present invention, a PWM is used to generate a pulse wave to control the conduction of the MOS transistor, thereby generating a CP signal of plus and minus 12V. At the same time, regardless of whether the PE signal is +12V or 0V, the reverse - parallel optocoupler can be conducted to detect the CC signal, reducing the circuit complexity and cost expenditure. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It shows the circuit diagram of a single - power charging pile circuit in an embodiment of the present invention.

[0020] The reference of the reference numerals corresponding to the drawings in the specification is as follows:

[0021] The first triode Q1, the MOS transistor Q2, the second triode Q3, the third triode Q4, the fourth triode Q5, the fifth triode Q6, the first signal isolator U1, the second signal isolator U2, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the first capacitor C1, the second capacitor C2, the first clamping diode D1, the second clamping diode D2. Detailed Embodiments

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. In this text, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element.

[0024] In the prior art, for the communication between an AC charging pile and an on-vehicle OBC, a dual-power supply scheme is generally adopted to meet the requirement of the on-vehicle OBC for the CP signal of ±12V. However, the adoption of a dual-power supply will increase the design complexity, and also lead to an over-large circuit volume, an increased PCB area and an increased cost. In addition, the dual-power supply may also reduce the reliability of the system. The embodiments of the present invention provide the following solution:

[0025] As Figure 1 shown, the embodiments of the present invention provide a charging pile circuit based on a single power supply, which includes a PE signal terminal, a CP signal terminal, a CC signal terminal, a PWM generator, a first triode Q1, a MOS tube Q2, a first emitter follower, a second emitter follower, a first signal isolator U1 and a second signal isolator U2. The first signal isolator U1 and the second signal isolator U2 are reversely connected in parallel. The PWM generator is connected to the emitter of the first triode Q1. The base of the first triode Q1 is connected to the power supply voltage VCC through a first resistor R1. The collector of the first triode Q1 is connected to the power supply voltage of 12V through a second resistor R2 and is connected to the gate of the MOS tube Q2 through a third resistor R3. The drain of the MOS tube Q2 is connected to the power supply voltage of 12V through a fourth resistor R4, and the source of the MOS tube Q2 is grounded. The input end of the first emitter follower is respectively connected to the collector of the first triode Q1, the second resistor R2 and the third resistor R3. The output end of the first emitter follower is respectively connected to the cathode of the first signal isolator U1 and the anode of the second signal isolator U2. The anode of the first signal isolator U1 and the cathode of the second signal isolator U2 are respectively connected to the power supply voltage VCC through a fifth resistor R5. The input end of the second emitter follower is respectively connected to the fourth resistor R4 and the drain of the MOS tube Q2. The output end of the second emitter follower is connected to the PE signal terminal. The CP signal terminal is connected to the output end of the first emitter follower through a sixth resistor R6. The CC signal terminal is respectively connected to the cathode of the first signal isolator U1 and the anode of the second signal isolator U2 through a seventh resistor R7.

[0026] PE (Protective Earth), protective grounding, ensures reliable grounding of the charging device and the vehicle housing, preventing leakage or electric shock risks.

[0027] CP (Control Pilot), control pilot signal, confirms whether the charging gun is correctly inserted into the vehicle socket.

[0028] CC (Connection Check), connection confirmation, determines the rated current of the charging cable by measuring the resistance of the CC pin.

[0029] It should be noted that the PWM signal of the PWM generator comes from the wave generation of the timer pin of the MCU. The first triode Q1 and the first resistor R1 form a level conversion circuit. When the PWM output is 0V, the first triode Q1 conducts through the first resistor R1. At this time, the voltage at the connection of the second resistor R2 and the third resistor R3 is 0V, and the output voltage of the first emitter follower is 0V. Since the gate voltage of the MOS tube Q2 is 0V, the MOS tube Q2 does not conduct. At this time, the voltage at the connection of the MOS tube Q2 and the fourth resistor R4 is 12V, and the output of the second emitter follower is 12V. The voltage between the PE signal terminal and the CP signal terminal of the connector CN1 is -12V. When the PWM output is 3.3V, the voltage at the connection of the second resistor R2 and the third resistor R3 is close to 12V, and the output voltage of the first emitter follower is close to 12V. Since the gate voltage of the MOS tube Q2 is 12V, the MOS tube Q2 conducts. At this time, the voltage at the connection of the MOS tube Q2 and the fourth resistor R4 is 0V, and the output of the second emitter follower is 0V. The voltage between the PE signal terminal and the CP signal terminal of the connector CN1 is +12V. When there is a positive voltage between the CP signal terminal and the PE signal terminal, it is sent to the analog-to-digital port of the single-chip microcomputer for detection. Therefore, only a 12V power supply is needed to generate positive and negative 12V CP signals through the emitter follower switching, thus reducing costs and complexity.

[0030] Specifically, when the charging gun is inserted into the vehicle, the CC pin at the vehicle end pulls down PE through a resistor. If the voltage of the PE signal terminal is +12V, the first signal isolator U1 conducts; if the voltage of the PE signal terminal is +0V, the second signal isolator U2 conducts. The MCU detects the output signal of the signal isolator to judge the connection state. When the charging gun is not inserted into the vehicle, there is no current in the primary side of the signal isolator, the secondary side is cut off, and the MCU detects a high impedance state.

[0031] In some embodiments, the first emitter follower includes a second triode Q3 and a third triode Q4. The bases of the second triode Q3 and the third triode Q4 are both connected to the collector of the first triode Q1, the second resistor R2, and the third resistor R3. The collector of the second triode Q3 is connected to the power supply voltage of 12V, and the collector of the third triode Q4 is grounded. The emitters of the second triode Q3 and the third triode Q4 are both connected to the sixth resistor R6, the anode of the first signal isolator U1, and the cathode of the second signal isolator U2. It can be understood that the second triode Q3 and the third triode Q4 form a bridge-arm emitter follower to ensure a low output impedance and a strong driving ability.

[0032] In some embodiments, the second emitter follower includes a fourth triode Q5 and a fifth triode Q6. The bases of the fourth triode Q5 and the fifth triode Q6 are both connected to the drain of the MOS transistor Q2 and the fourth resistor R4. The collector of the fourth triode Q5 is connected to the power supply voltage of 12V, the collector of the fifth triode Q6 is grounded, and the emitters of the fourth triode Q5 and the fifth triode Q6 are both connected to the PE signal terminal. It can be understood that the fourth triode Q5 and the fifth triode Q6 form a bridge-arm emitter follower to ensure a low output impedance and a strong driving ability.

[0033] In some embodiments, an eighth resistor is connected between the base and the source of the MOS transistor, so as to ensure that the MOS transistor remains reliably turned off when there is no driving signal, and to avoid accidental conduction caused by mis-triggering or noise interference.

[0034] In some embodiments, the charging pile circuit further includes a first capacitor C1. One end of the first capacitor C1 is respectively connected to the fifth resistor R5, the cathode of the first signal isolator U1, and the anode of the second signal isolator U2.

[0035] It should be noted that the first capacitor C1 plays a filtering role to filter the dead time during conversion.

[0036] In some embodiments, a voltage-dividing and filtering circuit is connected to one end of the sixth resistor R6. The voltage-dividing and filtering circuit includes a ninth resistor R9, a tenth resistor R10, and a second capacitor C2. One end of the ninth resistor R9 is connected to the sixth resistor R6, the other end of the ninth resistor R9 is respectively connected to one end of the tenth resistor R10 and one end of the second capacitor C2, and the other ends of the tenth resistor R10 and the second capacitor C2 are grounded.

[0037] It should be noted that the ninth resistor R9 and the tenth resistor R10 are used for voltage division to convert to the voltage range that the MCU can obtain, and the second capacitor C2 is used for filtering to increase the accuracy of the signal.

[0038] In some embodiments, the voltage dividing and filtering circuit further includes a first clamping diode D1 and a second clamping diode D2. The negative electrode of the first clamping diode D1 is respectively connected to the positive electrode of the second clamping diode D2, the ninth resistor R9, and the tenth resistor R10. The positive electrode of the first clamping diode D1 is grounded, and the negative electrode of the second clamping diode D2 is connected to the power supply voltage.

[0039] It should be noted that the first clamping diode D1 and the second clamping diode protect the MCU input from overvoltage and improve the service life of the MCU.

[0040] In some embodiments, both the first signal isolator U1 and the second signal isolator U2 are optocouplers.

[0041] In summary, the embodiments of the present invention provide a single - power charging pile circuit. The PWM is used to generate a pulse wave to control the conduction of the MOS transistor to generate a CP signal of plus and minus 12V. At the same time, through the optocoupler connected in reverse parallel, the CC signal can be detected whether the PE signal is 12V or 0V, reducing the circuit complexity and cost expenditure.

[0042] The above content is only the specific implementation manner of the present application, and the protection scope of the present application is not limited thereto. Those skilled in the art can make changes or substitutions within the technical scope disclosed in the present application, and these changes or substitutions should be within the protection scope of the present application.

[0043] Those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present invention and forms different embodiments.

[0044] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A charging pile circuit based on a single power supply, characterized in that, It includes a PE signal terminal, a CP signal terminal, a CC signal terminal, a PWM generator, a first triode, a MOS transistor, a first emitter follower, a second emitter follower, a first signal isolator and a second signal isolator, and the first signal isolator and the second signal isolator are reversely connected in parallel. The PWM generator is connected to the emitter of the first triode. The base of the first triode is connected to the power supply voltage through a first resistor. The collector of the first triode is connected to the power supply voltage through a second resistor and is connected to the gate of the MOS transistor through a third resistor. The drain of the MOS transistor is connected to the power supply voltage through a fourth resistor, and the source of the MOS transistor is grounded. The input terminal of the first emitter follower is respectively connected to the collector of the first triode, the second resistor and the third resistor. The output terminal of the first emitter follower is respectively connected to the cathode of the first signal isolator and the anode of the second signal isolator. The anode of the first signal isolator and the cathode of the second signal isolator are respectively connected to the power supply voltage through a fifth resistor. The input terminal of the second emitter follower is respectively connected to the fourth resistor and the drain of the MOS transistor, and the output terminal of the second emitter follower is connected to the PE signal terminal. The CP signal terminal is connected to the output terminal of the first emitter follower through a sixth resistor. The CC signal terminal is respectively connected to the cathode of the first signal isolator and the anode of the second signal isolator through a seventh resistor. The first emitter follower includes a second triode and a third triode. The bases of the second triode and the third triode are both connected to the collector of the first triode, the second resistor and the third resistor. The collector of the second triode is connected to the power supply voltage, and the collector of the third triode is grounded. The emitters of the second triode and the third triode are both connected to the sixth resistor, the anode of the first signal isolator and the cathode of the second signal isolator. The second emitter follower includes a fourth triode and a fifth triode. The bases of the fourth triode and the fifth triode are both connected to the drain of the MOS transistor and the fourth resistor. The collector of the fourth triode is connected to the power supply voltage, and the collector of the fifth triode is grounded. The emitters of the fourth triode and the fifth triode are both connected to the PE signal terminal.

2. The charging pile circuit based on a single power supply according to claim 1, characterized in that An eighth resistor is connected between the base and the source of the MOS transistor.

3. The charging pile circuit based on a single power supply according to claim 1, characterized in that, The charging pile circuit further includes a first capacitor. One end of the first capacitor is respectively connected to the fifth resistor, the cathode of the first signal isolator and the anode of the second signal isolator.

4. The charging pile circuit based on a single power supply according to claim 1, characterized in that, A voltage dividing and filtering circuit is connected to one end of the sixth resistor.

5. The charging pile circuit based on a single power supply according to claim 4, wherein The voltage dividing and filtering circuit includes a ninth resistor, a tenth resistor and a second capacitor. One end of the ninth resistor is connected to the sixth resistor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and one end of the second capacitor, and the other end of the tenth resistor and the other end of the second capacitor are grounded.

6. The charging pile circuit based on a single power supply according to claim 5, wherein The voltage dividing and filtering circuit further includes a first clamping diode and a second clamping diode. The negative electrode of the first clamping diode is respectively connected to the positive electrode of the second clamping diode, the ninth resistor, and the tenth resistor; the positive electrode of the first clamping diode is grounded, and the negative electrode of the second clamping diode is connected to the power supply voltage.

7. The single - power - based charging pile circuit according to any one of claims 1 to 6, characterized in that, The first signal isolator is an optocoupler.

8. The single - power - based charging pile circuit according to any one of claims 1 to 6, characterized in that, The second signal isolator is an optocoupler.

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