Circuit and method for slow charging pilot signal voltage detection

Abstract

The embodiment of the present invention provides a circuit and method for slow charging guide signal voltage detection, which belongs to the field of control technology of charging guns. The circuit includes: a voltage sampling and conditioning unit, which is used to receive a slow charging guide signal and perform voltage regulation operations on the slow charging guide signal; a switch control unit, one end of the switch control unit is connected to the voltage sampling and conditioning unit; a CP signal duty cycle detection unit, one end of the CP signal duty cycle detection unit is connected to one end of the voltage sampling and conditioning unit, and the other end of the CP signal duty cycle detection unit is used to output a PWM signal. Through the above technical solution, the circuit and method for slow charging guide signal voltage detection provided by the present invention realize real-time measurement of the CP signal amplitude in both the on and off states by setting a switch control unit and a voltage sampling and conditioning unit, and the CP signal duty cycle detection unit can simultaneously measure the duty cycle of the CP signal.

Description

Technical Field

[0001] The present invention relates to the field of charging gun control technology, and in particular to a circuit and method for detecting the voltage of a slow charging guide signal. Background Art

[0002] At present, the world is paying more and more attention to electric new energy vehicle technology, and the charging technology of new energy vehicles is also a key development and research object in various countries.

[0003] my country's "Electric Vehicle Conductive Charging System Part 1: General Requirements" standard specifies the interaction process between slow-charging signals and the BMS. The BMS and slow-charging pile exchange the EV's charging status and the pile's charging current limit via the Control Pilot (CP) signal. Existing technology uses the CP signal voltage to determine the EV's connection and charging status. The BMS then determines and responds to the pile's current output capacity and connection status by monitoring the CP signal's duty cycle and controlling the state of the S2 switch. However, existing technology lacks a conversion circuit for the CP signal, requiring the BMS to modify the national standard resistor when making its determination. This modification, in turn, affects the recognition of other slow-charging CP signals. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a circuit and method for slow charging pilot signal voltage detection, which can improve the application range of BMS for slow charging CP signal recognition.

[0005] To achieve the above objectives, an embodiment of the present invention provides a circuit for detecting a slow charge pilot signal voltage, comprising:

[0006] a voltage sampling and conditioning unit, configured to receive a slow charge pilot signal and perform a voltage regulation operation on the slow charge pilot signal;

[0007] A switch control unit, one end of which is connected to the voltage sampling and conditioning unit;

[0008] A CP signal duty cycle detection unit, one end of which is connected to one end of the voltage sampling and conditioning unit, and the other end of which is used to output a PWM signal.

[0009] Optionally, the voltage sampling and conditioning unit includes:

[0010] a first diode, wherein an anode of the first diode is used to receive a slow charge guide signal;

[0011] a first resistor, wherein one end of the first resistor is connected to the cathode of the first diode;

[0012] a second resistor, one end of the second resistor being connected to the other end of the first resistor, and the other end of the second resistor being grounded;

[0013] a first operational amplifier, wherein a non-inverting input terminal of the first operational amplifier is connected to the other end of the first resistor, and an output terminal of the first operational amplifier is connected to an inverting input terminal of the first operational amplifier;

[0014] a third resistor, one end of the third resistor being connected to the output end of the first operational amplifier, and the other end of the third resistor being used to output a voltage sampling signal of a slow charge guide signal;

[0015] A first capacitor, one end of the first capacitor is connected to the other end of the third resistor, and the other end of the first capacitor is grounded.

[0016] Optionally, the switch control unit includes:

[0017] a fourth resistor, one end of the fourth resistor being connected to the other end of the first resistor;

[0018] a first switching tube, wherein one end of the first switching tube is connected to one end of the fourth resistor, and the other end of the first switching tube is grounded;

[0019] a fifth resistor, one end of the fifth resistor being connected to the control end of the first switch tube, and the other end of the fifth resistor being configured to receive a switch control signal;

[0020] a sixth resistor, one end of the sixth resistor being connected to one end of the fifth resistor, and the other end of the sixth resistor being connected to the other end of the first switching tube.

[0021] Optionally, the CP signal duty cycle detection unit includes:

[0022] a seventh resistor, one end of which is externally connected to a DC voltage;

[0023] a second switching tube, wherein one end of the second switching tube is connected to one end of the seventh resistor, and a control end of the second switching tube is connected to the other end of the seventh resistor;

[0024] an eighth resistor, one end of the eighth resistor being connected to the control end of the second switching tube;

[0025] a third switching tube, wherein a control terminal of the third switching tube is connected to one end of the fourth resistor, one end of the third switching tube is grounded, and the other end of the third switching tube is connected to the other end of the eighth resistor;

[0026] a ninth resistor, one end of the ninth resistor being connected to the other end of the second switch tube, and the other end of the ninth resistor being grounded;

[0027] a tenth resistor, one end of the tenth resistor being connected to one end of the ninth resistor, and the other end of the tenth resistor being used to output the PWM signal.

[0028] Optionally, the sum of the resistances of the first resistor and the second resistor is 2.7 kΩ.

[0029] Optionally, the circuit further includes a controller connected to the other end of the third resistor, the other end of the fifth resistor, and the other end of the tenth resistor, and the controller is configured to:

[0030] Inputting a low level to the other end of the fifth resistor to turn off the second switch tube;

[0031] The amplitude of the slow charge guidance signal is calculated according to formula (1):

[0032] , (1)

[0033] in, is the amplitude, is the output voltage at the other end of the third resistor, is the resistance of the first resistor, is the resistance of the second resistor, It is the series resistor inside the slow charging gun.

[0034] Optionally, the controller is further configured to:

[0035] Inputting a high level to the other end of the fifth resistor to close the second switch tube;

[0036] The amplitude of the slow charge guidance signal is calculated according to formula (2):

[0037] , (2)

[0038] in, is the resistance of the fourth resistor.

[0039] On the other hand, the present invention also provides a method for detecting a slow charge pilot signal voltage, the method comprising:

[0040] Preset the circuit as described above;

[0041] Inputting a low level to the other end of the fifth resistor to turn off the second switch tube;

[0042] According to formula (1), the amplitude of the slow charging guidance signal is calculated.

[0043] , (1)

[0044] in, is the amplitude, is the output voltage at the other end of the third resistor, is the resistance of the first resistor, is the resistance of the second resistor, It is the series resistor inside the slow charging gun.

[0045] Optionally, the method comprises:

[0046] Inputting a high level to the other end of the fifth resistor to close the second switch tube;

[0047] According to formula (2), the amplitude of the slow charge guidance signal is calculated:

[0048] , (2)

[0049] in, is the resistance of the fourth resistor.

[0050] In another aspect, the present invention further provides a computer-readable storage medium storing instructions, wherein the instructions are configured to be read by a machine so as to enable the machine to execute any of the above methods.

[0051] Through the above technical solution, the circuit and method for slow charging pilot signal voltage detection provided by the present invention realize real-time measurement of the CP signal amplitude in both the on and off states by setting a switch control unit and a voltage sampling and conditioning unit, while the CP signal duty cycle detection unit can simultaneously measure the duty cycle of the CP signal.

[0052] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0054] Figure 1 4 is a circuit diagram of a circuit for detecting a slow charge pilot signal voltage according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0056] like Figure 1FIG. 1 is a circuit diagram of a circuit for detecting a slow charge pilot signal voltage according to an embodiment of the present invention. Figure 1 The circuit may include a voltage sampling and conditioning unit 01, a switch control unit 02, and a CP signal duty cycle detection unit 03. The voltage sampling and conditioning unit 01 may be configured to receive a slow charge pilot signal and perform voltage regulation on the slow charge pilot signal. One end of the switch control unit 02 may be connected to the voltage sampling and conditioning unit 01. One end of the CP signal duty cycle detection unit 03 may be connected to one end of the voltage sampling and conditioning unit, and the other end of the CP signal duty cycle detection unit 03 may be configured to output a PWM signal.

[0057] In this embodiment, the specific structure of the voltage sampling and conditioning unit 01 may further include a first diode D1, a first resistor R1, a second resistor R2, a first operational amplifier U1, a third resistor R3 and a first capacitor C1. Among them, the positive electrode of the first diode D1 can be used to receive a slow charging guide signal. One end of the first resistor R1 can be connected to the negative electrode of the first diode D1. One end of the second resistor R2 can be connected to the other end of the first resistor R1, and the other end of the second resistor R2 can be grounded. The non-inverting input terminal of the first operational amplifier U1 can be connected to the other end of the first resistor R1, and the output terminal of the first operational amplifier U1 can be connected to the inverting input terminal of the first operational amplifier U1. One end of the third resistor R3 can be connected to the output terminal of the first operational amplifier U1, and the other end of the third resistor R3 can be used to output a voltage sampling signal of the slow charging guide signal. One end of the first capacitor C1 can be connected to the other end of the third resistor R3, and the other end of the first capacitor C1 can be grounded.

[0058] In this embodiment, the specific structure of the switch control unit 02 may further include a fourth resistor R4, a first switch tube Q1, a fifth resistor R5, and a sixth resistor R6. One end of the fourth resistor R4 may be connected to the other end of the first resistor R1. One end of the first switch tube Q1 may be connected to one end of the fourth resistor R4 and the other end of the fourth resistor R4, and the other end of the first switch tube Q1 may be grounded. One end of the fifth resistor R5 may be connected to the control end of the first switch tube Q1, and the other end of the fifth resistor R5 may be used to receive a switch control signal. One end of the sixth resistor R6 may be connected to one end of the fifth resistor R5, and the other end of the sixth resistor R6 may be connected to the other end of the first switch tube Q1.

[0059] In this embodiment, the specific structure of the CP signal duty cycle detection unit 03 may further include a seventh resistor R7, a second switch Q2, an eighth resistor R8, a third switch Q3, a ninth resistor R9, and a tenth resistor R10. One end of the seventh resistor R7 may be externally connected to a DC voltage. One end of the second switch Q2 may be connected to one end of the seventh resistor R7, and the control end of the second switch Q2 may be connected to the other end of the seventh resistor R7. One end of the eighth resistor R8 may be connected to the control end of the second switch Q2. The control end of the third switch Q3 may be connected to one end of the fourth resistor R4, one end of the third switch Q3 may be grounded, and the other end of the third switch Q3 may be connected to the other end of the eighth resistor R8. One end of the ninth resistor R9 may be connected to the other end of the second switch Q2, and the other end of the ninth resistor R9 may be grounded. One end of the tenth resistor R10 may be connected to one end of the ninth resistor R9, and the other end of the tenth resistor R10 may be used to output a PWM signal.

[0060] Through this Figure 1 In the circuit shown, the first resistor R1 and the second resistor R2 can form a voltage divider network. On the other hand, the sum of the resistance values ​​of the first resistor R1 and the second resistor R2 can also be 2.7kΩ, which is equivalent to the resistance in the international slow charging interface circuit, thus taking into account the functions of national standard resistance and voltage divider, saving circuit components. In addition, to meet the above requirements, the first resistor R1 and the second resistor R2 can also meet the following conditions:

[0061] .

[0062] Through this Figure 1 In the circuit shown, after the diode D1, the ±CP signal is first converted into a voltage signal greater than 0V through the diode. After passing through the voltage detection and conditioning circuit, the CP_Volt signal is input into the ADC port of the microcontroller for acquisition.

[0063] After the CP signal access detection starts, the controller can calculate the CP signal voltage at this time by judging and controlling whether the switch control unit 02 is closed and the CP_Volt voltage value collected by the ADC. In one example of the present invention, if the controller can input a low level to the other end of the fifth resistor R5 to disconnect the second switch tube Q2, and then calculate the amplitude of the slow charge guide signal according to formula (1),

[0064] , (1)

[0065] in, is the amplitude, is the output voltage of the other end of the third resistor R3, is the resistance of the first resistor R1, is the resistance of the second resistor R2, It is the series resistor inside the slow charging gun.

[0066] In another example of the present invention, the controller may be configured to first input a high level to the other end of the fifth resistor R5 to close the second switch Q2, and then calculate the amplitude of the slow charge guide signal according to formula (2):

[0067] , (2)

[0068] in, is the resistance of the fourth resistor R4.

[0069] On the other hand, the present invention also provides a method for detecting the voltage of a slow charge pilot signal, which can be achieved by Figure 1 The circuit shown first inputs a low level to the other end of the fifth resistor R5 to turn off the second switch Q2, and then calculates the amplitude of the slow charge guide signal according to formula (1):

[0070] , (1)

[0071] in, is the amplitude, is the output voltage of the other end of the third resistor R3, is the resistance of the first resistor R1, is the resistance of the second resistor R2, It is the series resistor inside the slow charging gun.

[0072] In one embodiment of the present invention, the method may also be to first input a high level to the other end of the fifth resistor R5 to close the second switch Q2, and then calculate the amplitude of the slow charge guide signal according to formula (2):

[0073] , (2)

[0074] in, is the resistance of the fourth resistor R4.

[0075] In yet another aspect, the present invention further provides a computer-readable storage medium storing instructions, wherein the instructions are configured to be read by a machine so as to enable the machine to execute any of the above methods.

[0076] Through the above technical solution, the circuit and method for slow charging pilot signal voltage detection provided by the present invention realize real-time measurement of the CP signal amplitude in both the on and off states by setting a switch control unit and a voltage sampling and conditioning unit, while the CP signal duty cycle detection unit can simultaneously measure the duty cycle of the CP signal.

[0077] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0078] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0079] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0080] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0081] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0082] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0083] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can be implemented using any method or technology to store information. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change RAM (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media such as modulated data signals and carrier waves.

[0084] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0085] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A circuit for slow charge pilot signal voltage detection, characterized in that: The circuit comprises: a voltage sampling and conditioning unit, configured to receive a slow charge pilot signal and perform a voltage regulation operation on the slow charge pilot signal; A switch control unit, one end of which is connected to the voltage sampling and conditioning unit; a CP signal duty cycle detection unit, one end of which is connected to one end of the voltage sampling and conditioning unit, and the other end of which is used to output a PWM signal; The voltage sampling and conditioning unit includes: a first diode, wherein an anode of the first diode is used to receive a slow charge guide signal; a first resistor, wherein one end of the first resistor is connected to the cathode of the first diode; a second resistor, one end of the second resistor being connected to the other end of the first resistor, and the other end of the second resistor being grounded; a first operational amplifier, wherein a non-inverting input terminal of the first operational amplifier is connected to the other end of the first resistor, and an output terminal of the first operational amplifier is connected to an inverting input terminal of the first operational amplifier; a third resistor, one end of the third resistor being connected to the output end of the first operational amplifier, and the other end of the third resistor being used to output a voltage sampling signal of a slow charge guide signal; a first capacitor, one end of the first capacitor being connected to the other end of the third resistor, and the other end of the first capacitor being grounded; The switch control unit includes: a fourth resistor, one end of the fourth resistor being connected to the other end of the first resistor; a first switching tube, wherein one end of the first switching tube is connected to one end of the fourth resistor, and the other end of the first switching tube is grounded; a fifth resistor, one end of the fifth resistor being connected to the control end of the first switch tube, and the other end of the fifth resistor being configured to receive a switch control signal; a sixth resistor, one end of the sixth resistor being connected to one end of the fifth resistor, and the other end of the sixth resistor being connected to the other end of the first switching tube; The CP signal duty cycle detection unit includes: a seventh resistor, one end of which is externally connected to a DC voltage; a second switching tube, wherein one end of the second switching tube is connected to one end of the seventh resistor, and a control end of the second switching tube is connected to the other end of the seventh resistor; an eighth resistor, one end of the eighth resistor being connected to the control end of the second switching tube; a third switching tube, wherein a control terminal of the third switching tube is connected to one end of the fourth resistor, one end of the third switching tube is grounded, and the other end of the third switching tube is connected to the other end of the eighth resistor; a ninth resistor, one end of the ninth resistor being connected to the other end of the second switch tube, and the other end of the ninth resistor being grounded; a tenth resistor, one end of the tenth resistor being connected to one end of the ninth resistor, and the other end of the tenth resistor being used to output the PWM signal; The circuit further includes a controller connected to the other end of the third resistor, the other end of the fifth resistor, and the other end of the tenth resistor, and configured to: Inputting a low level to the other end of the fifth resistor to turn off the second switch tube; The amplitude of the slow charge guidance signal is calculated according to formula (1): ，（1） in, is the amplitude, is the output voltage at the other end of the third resistor, is the resistance of the first resistor, is the resistance of the second resistor, It is the series resistor inside the slow charging gun; The controller is also used to: Inputting a high level to the other end of the fifth resistor to close the second switch tube; The amplitude of the slow charge guidance signal is calculated according to formula (2): ，（2） in, is the resistance of the fourth resistor.

2. The circuit according to claim 1, wherein: The total resistance of the first resistor and the second resistor is 2.7 kΩ.

3. A method for detecting the voltage of a slow charge pilot signal, characterized in that: The method comprises: Preset the circuit as claimed in claim 1; Inputting a low level to the other end of the fifth resistor to turn off the second switch tube; According to formula (1), the amplitude of the slow charging guidance signal is calculated. ，（1） in, is the amplitude, is the output voltage at the other end of the third resistor, is the resistance of the first resistor, is the resistance of the second resistor, It is the series resistor inside the slow charging gun; The method comprises: Inputting a high level to the other end of the fifth resistor to close the second switch tube; According to formula (2), the amplitude of the slow charge guidance signal is calculated: ，（2） in, is the resistance of the fourth resistor.

4. A computer-readable storage medium, characterized in that The computer-readable storage medium stores instructions, and the instructions are configured to be read by a machine so as to cause the machine to execute the method according to claim 3 .

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