A slow charging CP wake-up system for electric vehicles

Abstract

The present invention provides an electric vehicle slow charging CP wake-up system, comprising a switch circuit, a DC power conversion circuit, a CP wake-up circuit, a signal acquisition circuit and an MCU control circuit, wherein the output end of the CP wake-up circuit is connected to the input end of the switch circuit, the output end of the switch circuit is connected to the DC power conversion circuit, the output end of the DC power conversion circuit is respectively connected to the signal acquisition circuit and the MCU control circuit, the output end of the signal acquisition circuit is connected to the input end of the MCU control circuit, the first circuit detects and amplifies the water body voltage, and the present invention adds a charge discharge resistor at both ends of the capacitor, when the customer unplugs the charging gun, the internal charge of the capacitor is discharged through the resistor, ensuring that the battery management system can be successfully awakened when the customer re-inserts the gun.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle charging, and in particular to a slow charging CP wake-up system for an electric vehicle. Background Art

[0002] According to GBT 18487.1-2015 General Requirements for Electric Vehicle Conductive Charging System Part 1, after the slow charging pile is charged, the CP signal changes from a PWM signal to a 12V high-level signal. The two existing CP wake-up circuits have the following problems:

[0003] The RC integral circuit unit is used to implement the CP wake-up function. The problem with this circuit is that after the slow charge is completed, CP is at a high level of 12V to continuously wake up the battery management system. If the slow charge gun is not unplugged for a long time, it may cause the 12V lead-acid battery of the electric vehicle to run out of power. The next time the customer uses the vehicle, the vehicle cannot be started.

[0004] The CP wake-up function is implemented using a differential circuit unit. The capacitor in the differential circuit unit lacks a discharge circuit. When the customer unplugs the slow charging gun for some reason and then plugs it back in, the internal charge of the capacitor in the differential circuit is not discharged, causing the wake-up function to fail. Summary of the invention

[0005] The present invention provides an electric vehicle slow charging CP wake-up system to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A slow-charging CP wake-up system for an electric vehicle comprises a switch circuit, a DC power conversion circuit, a CP wake-up circuit, a signal acquisition circuit and an MCU control circuit, wherein the output end of the CP wake-up circuit is connected to the input end of the switch circuit, the output end of the switch circuit is connected to the DC power conversion circuit, the output end of the DC power conversion circuit is respectively connected to the signal acquisition circuit and the MCU control circuit, and the output end of the signal acquisition circuit is connected to the input end of the MCU control circuit, wherein:

[0008] The CP wake-up circuit includes a capacitor C2, an NPN transistor Q3 connected to the output end of the capacitor C2, a resistor R2 connected to both ends of C2, and the NPN transistor Q2, the emitter of the NPN transistor Q3 is grounded, the collector of the NPN transistor Q3 is connected to the switch circuit and then connected to the NPN transistor Q2, wherein the resistance value of the resistor R2 is 0.9~1.1MΩ.

[0009] Furthermore, the switch circuit includes a MOS tube Q1, a source and a gate of the MOS tube Q1 are connected through a resistor R7, then connected to a resistor R1 and connected to a collector of an NPN transistor Q3, and a drain of the MOS tube Q1 is connected to a DC power conversion circuit.

[0010] Furthermore, the signal acquisition circuit includes a CP signal acquisition circuit and a CC signal acquisition circuit.

[0011] Furthermore, the DC power conversion circuit includes a DC power conversion chip U10 for accessing a 12V power supply of the switch circuit and realizing circuit output voltage regulation.

[0012] Furthermore, the CP signal acquisition circuit includes a diode D20, resistors R24, R23, R22, a transistor Q20 and a MOS tube Q21, the anode of the diode D20 is connected to the CP signal, the cathode of D20 is connected to R23 and R24 in sequence and then connected to R22, the other end of R24 is grounded, the other end of R22 is connected to the base of the transistor Q20, the emitter of Q20 is grounded, the collector of Q20 is connected to the MCU control circuit, the other end of R23 is connected to the drain of the MOS tube Q21, and the gate and source of Q21 are connected to the S2 signal through R26.

[0013] Furthermore, the CC signal acquisition circuit includes a signal filter capacitor C31, resistors R30, R31, a filter capacitor C30 and a clamping diode D30. The signal filter capacitor C31 is connected to R30, R31, C30 and D30 in sequence and then connected to the MCU control circuit.

[0014] Furthermore, the MCU control circuit includes a microcontroller U40.

[0015] It can be seen from the above technical scheme that the present invention has the following beneficial effects: when the vehicle is slowly charged, the CP wake-up circuit briefly wakes up the battery management system, and then the CP wake-up function fails and the IG_KEEP signal output by the battery management system MCU control circuit takes over the wake-up until the MCU stops outputting the IG_KEEP signal after the slow charging is completed, thereby realizing the power-off function of the battery management system after the slow charging is completed; in addition, a charge discharge resistor is added at both ends of the capacitor. When the customer unplugs the charging gun, the charge inside the capacitor is discharged through this resistor, ensuring that the battery management system can be successfully woken up when the customer reinserts the gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work.

[0017] Figure 1 It is a schematic diagram of the system of the present invention;

[0018] Figure 2 This is a schematic diagram of the CP wake-up circuit and the power switch circuit of the present invention;

[0019] Figure 3 This is a schematic diagram of a DC power conversion circuit of the present invention;

[0020] Figure 4 This is a schematic diagram of the CP signal acquisition circuit of the present invention;

[0021] Figure 5 This is a schematic diagram of the CC signal acquisition circuit of the present invention;

[0022] Figure 6 It is a schematic diagram of the MCU control circuit of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, a slow charging CP wake-up system for an electric vehicle includes a switch circuit, a DC power conversion circuit, a CP wake-up circuit, a signal acquisition circuit and an MCU control circuit, wherein the signal acquisition circuit includes a CP signal acquisition circuit and a CC signal acquisition circuit, the output end of the CP wake-up circuit is connected to the input end of the switch circuit, the output end of the switch circuit is connected to the DC power conversion circuit, the output pad of the DC power conversion circuit is respectively connected to the signal acquisition circuit and the MCU control circuit, the output end of the signal acquisition circuit is connected to the input end of the MCU control circuit, wherein:

[0025] like Figure 2 As shown, the CP wake-up circuit includes capacitors C2, C3, voltage-stabilizing diodes D2, D3 and D4, resistors R4, R2, R5, R6 and R3, and NPN transistors Q3 and Q2, wherein D2, R4, C2, D3 and Q3 are connected in series in sequence, the cathode of D2 is connected to the CP signal acquisition circuit, the two ends of C2 are connected through R2 and then connected to R5, the other end of R5 is grounded, the emitter of Q3 is grounded, the collector of Q3 is connected to the collector of Q2, and the connection between Q3 and Q2 is connected to the switch circuit, the base of Q2 is connected to R6, C3, D4 and R3 in sequence, wherein R6 and C3 are connected in parallel and then connected to the emitter of Q2, and R6 is grounded, wherein the resistance of resistor R2 is 0.9~1.1MΩ, if the resistance is too small, the CP signal will directly wake up the battery management system through R2, if the resistance is too large, the charge discharge time of C2 will be prolonged, and the customer may fail to wake up when re-inserting the gun.

[0026] The switch circuit includes a voltage stabilizing diode D1, a MOS tube Q1, resistors R7 and R1, and a capacitor C1. The source and gate of the MOS tube Q1 are connected through the resistor R7, and then connected to the resistor R1 and connected to the collector of the NPN transistor Q3. The other end of R7 is connected to the cathode of D1. The drain of the MOS tube Q1 is connected to the DC power conversion circuit through C1, and the other end of C1 is grounded.

[0027] like Figure 3 As shown, the DC power conversion circuit includes a DC power conversion chip U10, capacitors C10, C11, C12, C13, C14, C15, C16, a Schottky diode D10, resistors R10, R11, R12, R13, R14, R15, a light emitting diode DS10, and an inductor L10.

[0028] The second pin of U10 is the 12V power input terminal, with an external decoupling capacitor C10, and the other end of C10 is connected to GND; the third pin of U10 is the chip enable signal input terminal, and the external resistor R10 is pulled up to 12V; the fourth pin of U10 is the switching frequency setting control, and the external resistor R15 is pulled down to GND; the sixth pin of U10 is the soft start control pin, and the external C16 is connected to GND; the first pin of U10 is externally connected to the bootstrap capacitor C11 to the eighth pin of U10, and the eighth pin of U10 is the switch control pin, and the cathode of the freewheeling diode D10 is externally connected, and the anode of the D10 diode is connected to GND; The 8-pin external energy storage inductor L10, the other end of L10 is connected to the filter capacitors C12, C13, C14, C15 to VCC, and the other ends of the capacitors C12, C13, C14, C15 are connected to GND; the resistors R11, R13, R14 are connected in series in sequence, one end of R11 is connected to VCC, one end of R14 is connected to GND, and the other end is connected to the 7th pin of U10. The 7th pin of U10 is the external feedback voltage pin, and the circuit output voltage regulation function is realized through this pin; DS10 is the power indicator LED diode, the cathode is connected to GND, and the positive pole is connected to the current limiting resistor R12 to VCC.

[0029] like Figure 4As shown, the CP acquisition circuit includes a Schottky diode D20, resistors R20, R21, R22, R23, R24, R25, R26, a transistor Q20, and a MOS tube Q21. The anode of the diode D20 is connected to the CP signal, the cathode of D20 is connected to R23 and R24 in sequence and then connected to R22, the other end of R24 is grounded, the other end of R22 is connected to the base of the transistor Q20, the emitter of Q20 is grounded, the collector of Q20 is connected to R21 and R20 in sequence, the other end of R21 is connected to the MCU control circuit, the other end of R20 is connected to VCC, the other end of R23 is the drain of the MOS tube Q21, the gate and source of Q21 are connected through R26 and then connected to R25, and the other end of R25 is connected to the S2 signal. The charging gun outputs a 12V high-level CP signal to the CP signal acquisition circuit. The CP signal is divided into 9V through resistor R24. The charging gun detects that the CP voltage is divided into 9V, and the CP signal is converted from a high-level signal to a PWM signal. The PWM signal is connected to the first pin of the three-stage tube Q20 through R22 to control Q20 to be continuously turned off and on. The PWM_CP port outputs a PWM signal to the MCU control circuit. After the MCU control circuit collects the PWM_CP signal, it controls the S2 signal to be high. The S2 signal turns on the MOS tube Q21, and R23 is connected to GND through Q21. The CP signal is divided into a 6V PWM signal through resistors R24 and R23.

[0030] like Figure 5 As shown, the CC signal acquisition circuit includes a signal filter capacitor C31, resistors R30, R31, a filter capacitor C30 and a clamping diode D30. The signal filter capacitor C31 is connected to R30, R31, C30 and D30 in sequence and then connected to the MCU control circuit. The other end of C31 is grounded, the other end of R30 is connected to VCC, the other end of C30 is grounded, one end of D30 is grounded, and the other end is connected to VCC. The CC signal connects the internal CC resistor of the charging gun to GND. VCC is divided by the CC resistor through the resistor R30, and then passes through the current limiting resistor R31, the filter capacitor C30, and the clamping diode D30 to output the AD_CC signal to the MCU control circuit.

[0031] like Figure 6As shown, the MCU control circuit includes a microcontroller U40, a crystal oscillator X40, a burning interface J40, capacitors C40, C41, C42, C43, C44, C45, C46, ​​C47, and resistors R40, R41, R42, wherein the model of the microcontroller U40 is S912XEP100W1MAG. One end of capacitor C40 is connected to the X40 XTAL pin, and the other end is connected to GND; one end of capacitor C41 is connected to the X40 EXTAL pin, and the other end is connected to GND; one end of resistor R41 is connected to the X40 XTAL pin, and the other end is connected to the X40 EXTAL pin; one end of resistor R40 is connected to the X40XTAL pin, and the other end is connected to the 59th pin of U40; one end of resistor R42 is connected to the X40 EXTAL pin, the other end is connected to U40 pin 58; capacitors C42, C43, C44, C45, C46, ​​and C47 are U40 power supply guidance filter capacitors, one end is connected to VCC and the other end is connected to GND; J40 is the U40 debugging interface, J40 pin 1 is connected to U40 pin 25, J40 pin 4 is connected to U40 pin 54, J40 pin 6 is connected to VCC, and J40 pin 2 is connected to GND; U40 pin 77 outputs IG_KEEP signal to the power switch circuit, U40 pin 17 outputs S2 signal to CP signal acquisition circuit, U40 pin 91 inputs AD_CC signal output by CC acquisition circuit, and U40 pin 12 inputs PWM_CP signal output by CP acquisition circuit.

[0032] Working process: When the new energy vehicle is plugged into the slow charging gun, the CC and CP signal acquisition circuits are normally connected to the vehicle's battery management system. The CP wake-up circuit outputs a short IG_CP signal to the DC power conversion circuit, and the system starts to power on. At the same time, the CP signal is connected. Using the characteristic that the voltage across the capacitor cannot change suddenly, the C2 capacitor is equivalent to a short-circuit state. The CP signal turns on the NPN transistor Q3 through the capacitor C2, and the G pole of the P-channel MOS tube Q1 is turned on to GND through Q3. Q1 is turned on, and the circuit outputs 12V. The battery management system of the car starts working, and the MCU control circuit outputs the IG_KEEP signal to turn on the NPN transistor Q2, and the G pole of the P-channel MOS tube Q1 is turned on to GND through Q2, and Q1 is continuously turned on.

[0033] As the charge of capacitor C2 is gradually filled, the CP signal cannot pass through C2 to turn on Q3, so that the CP wake-up function is automatically removed after a short wake-up. The MCU control circuit collects the PWM_CP signal and the AD_CC signal. If the signal is normal, the IG_KEEP signal is output to continuously take over and wake up the DC power conversion circuit until the slow charging is completed and then cut off to power off the battery management system. When the slow charging gun is unplugged, the charge of capacitor C2 is discharged through R2 to ensure that the battery management system can be successfully awakened when the customer re-inserts the gun. When the customer inserts the gun again, the CP signal briefly wakes up the battery management system through the C2 capacitor.

[0034] The above-described embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An electric vehicle slow charging CP wake-up system, characterized in that: It includes a switch circuit, a DC power conversion circuit, a CP wake-up circuit, a signal acquisition circuit and an MCU control circuit, wherein the output end of the CP wake-up circuit is connected to the input end of the switch circuit, the output end of the switch circuit is connected to the DC power conversion circuit, the output end of the DC power conversion circuit is respectively connected to the signal acquisition circuit and the MCU control circuit, and the output end of the signal acquisition circuit is connected to the input end of the MCU control circuit, wherein: The switch circuit includes a voltage stabilizing diode D1, a MOS transistor Q1, resistors R7 and R1, and a capacitor C1, wherein the positive electrode of the voltage stabilizing diode D1 is used to receive a BMS_POWER signal, the negative electrode of the voltage stabilizing diode D1 is connected to one end of the resistor R7 and the source of the MOS transistor Q1, the other end of the resistor R7 is connected to the gate of the MOS transistor Q1 and one end of the resistor R1, the drain of the MOS transistor Q1 is connected to the positive electrode of the capacitor C1 and a 12V power supply, the negative electrode of the capacitor C1 is grounded, and the other end of the resistor R1 is respectively connected to the collector of the NPN transistor Q3 and the collector of the NPN transistor Q2; The CP wake-up circuit includes capacitors C2, C3, voltage-stabilizing diodes D2, D3 and D4, resistors R4, R2, R5, R6 and R3, and NPN transistors Q3 and Q2; wherein the positive terminal of the diode D2 is used to receive the CP signal, the negative terminal of the diode D2 is connected to one end of the resistor R4, the other end of the resistor R4 is respectively connected to one end of the resistor R2 and one end of the capacitor C2, and the other end of the resistor R2 is respectively connected to the other end of the capacitor C2, the positive terminal of the diode D3 and one end of the resistor R5 , the other end of the resistor R5 is grounded, the cathode end of the diode D3 is connected to the base of the NPN transistor Q3, the emitter of the NPN transistor Q3 is grounded, the base of the NPN transistor Q2 is respectively connected to one end of the resistor R6, one end of the capacitor C3 and the cathode end of the diode D4, the emitter of the NPN transistor Q2, the other end of the resistor R6 and the other end of the capacitor C3 are all grounded, the anode end of the diode D4 is connected to one end of the resistor R3, and the other end of the resistor R3 is used to receive the IG_KEEP signal.

2. The electric vehicle slow charging CP wake-up system according to claim 1 is characterized in that: The signal acquisition circuit includes a CP signal acquisition circuit and a CC signal acquisition circuit.

3. The electric vehicle slow charging CP wake-up system according to claim 1 is characterized in that: The DC power conversion circuit includes a DC power conversion chip for accessing a 12V power supply of a switch circuit and realizing circuit output voltage regulation.

4. The electric vehicle slow charging CP wake-up system according to claim 1 is characterized in that: The MCU control circuit includes a microcontroller.

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