AC charging pile control guide CP circuit and CP acquisition method

Abstract

The invention discloses an AC charging pile control guide CP circuit and a CP acquisition method. The AC charging pile control guide CP circuit comprises a main controller MCU, a CP output circuit and a CP acquisition circuit. The CP output circuit comprises a comparator, the input end of the comparator is connected with a PWM output interface of the MCU, and the comparator is used for converting a PWM level signal into a voltage signal with a set size; the output end of the comparator is connected with a CP output interface; the CP output interface is connected with the CP acquisition circuit; according to the CP acquisition circuit, an ADC acquisition interface of a main controller MCU is connected with a CP output interface through a resistor R6 and a resistor R7 which are sequentially connected in series; a divider resistor is connected between the ADC acquisition interface of the main controller MCU and the reference voltage; and a divider resistor and a filter capacitor are respectively connected between the ADC acquisition interface of the main controller MCU and the ground wire. The CP voltage obtaining method is simple and accurate, the performance requirement for the main controller MCU is lowered, and meanwhile the accuracy of voltage detection is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging control, and in particular to an AC charging pile control guidance CP circuit and a CP acquisition method. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, the charging pile industry has developed rapidly. AC charging piles have occupied a place in the market due to their low price, small size and simple installation. According to the relevant standards of electric vehicle conductive charging system, there are clear requirements for the control and guidance function of AC charging piles in terms of control and guidance circuit parameters and control logic, detection point 1 voltage and corresponding charging process status monitoring, diode existence detection, etc. For example:

[0004] (1) Before energy transmission, the AC charging pile verifies whether the connected device is an electric vehicle or other non-load device by detecting the presence of diode D1 on the control pilot circuit; if the presence of diode D1 is detected, it means that the connected device is an electric vehicle or an electric vehicle simulator.

[0005] (2) When an AC charging pile charges an electric vehicle, it guides the charging pile through the CP line. The charging pile outputs DC or PWM through the CP line to notify the electric vehicle to prohibit or allow charging. At the same time, the charging pile needs to detect the voltage of the CP line and use the detected CP voltage result to determine the current connection status between the charging pile and the electric vehicle.

[0006] In the prior art, optocouplers and operational amplifiers are often used to implement control guidance output circuits. Resistors, capacitors, operational amplifiers, etc. are used to form CP detection circuits. In order to meet the requirements of relevant standards, two sets of positive and negative CP detection circuits are usually required. The circuit design is relatively complex and the cost is high. Summary of the invention

[0007] To solve the above problems, the present invention proposes an AC charging pile control guidance CP circuit and a CP acquisition method, which can realize effective control and monitoring of the CP output voltage of the AC charging pile while simplifying the circuit, and save the resources and costs of the AC charging pile controller.

[0008] In some embodiments, the following technical solutions are adopted:

[0009] An AC charging pile control and guidance CP circuit includes: a main controller MCU, a CP output circuit and a CP acquisition circuit;

[0010] The CP output circuit includes a comparator, the comparator input end is connected to the PWM output interface of the main controller MCU, and is used to convert the PWM level signal into a voltage signal of a set size; the comparator output end is connected to the CP output interface; the CP output interface is connected to the CP acquisition circuit;

[0011] The CP acquisition circuit includes: the ADC acquisition interface of the main controller MCU is connected to the CP output interface through resistors R6 and R7 connected in series in sequence; a voltage divider resistor is connected between the ADC acquisition interface of the main controller MCU and the reference voltage; and a voltage divider resistor and a filter capacitor are respectively connected between the ADC acquisition interface of the main controller MCU and the ground line.

[0012] Furthermore, the voltage-dividing resistor connected between the ADC acquisition interface of the main controller MCU and the reference voltage is specifically: a parallel branch composed of a resistor R8, a resistor R9 and a resistor R10 connected in parallel.

[0013] Furthermore, the voltage-dividing resistor connected between the ADC acquisition interface of the main controller MCU and the ground line is specifically: a parallel branch composed of a resistor R11 and a resistor R12 connected in parallel.

[0014] Furthermore, a resistor R1 is connected in series between the positive input end of the comparator and the PWM output interface of the main controller MCU; a pull-up resistor R2 and a grounding resistor R3 are respectively connected to the negative input end of the comparator; a parallel branch composed of a resistor R4 and a resistor R5 in parallel is connected between the output end of the comparator and the CP output interface; and a transient voltage suppression diode is connected in series between the CP output interface and the ground line.

[0015] Furthermore, the ADC of the main controller MCU collects the interface voltage and calculates the CP voltage, thereby determining the voltage state of the CP output interface; and the charging state of the AC charging pile and the existence of the diode are determined based on the voltage state of the CP output interface.

[0016] Furthermore, the CP voltage is calculated according to the ADC acquisition interface voltage of the main controller MCU, specifically:

[0017] V cp =a*V adc -b*V ref ;

[0018] Among them, V cp is the CP voltage, V adc is the voltage of the ADC acquisition interface of the main controller MCU, a and b are the proportional coefficients, V ref It is the reference voltage of MCU.

[0019] In other embodiments, the following technical solutions are adopted:

[0020] An AC charging pile control guidance CP collection method, comprising:

[0021] In one PWM cycle, the CP voltage is sampled S times continuously;

[0022] Determine the number N of CP voltage sampling values ​​that meet the CP positive phase voltage state P, and the number M of CP voltage sampling values ​​that meet the CP negative phase voltage state Q among the S CP voltage sampling values;

[0023] Determine the voltage state value and PWM output status corresponding to the CP positive phase voltage state P and the CP negative phase voltage state Q in the current PWM cycle based on the values ​​of the quantities N and M;

[0024] Based on the voltage state values ​​corresponding to the CP positive phase voltage state P and the CP negative phase voltage state Q of the most recent T consecutive cycles, the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q are updated; wherein S and T are both set positive integers;

[0025] Based on the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q, as well as the PWM output condition, the current charging connection state is determined, and the existence of the diode is verified;

[0026] The CP positive phase voltage state P refers to the case where the CP positive phase voltage is within one of the nominal values ​​of 6V, 9V or 12V when the PWM signal is output or not output;

[0027] The CP negative phase voltage state Q means that when a PWM signal is output, the CP negative phase voltage is within one of the nominal values ​​of -6V, -9V or -12V.

[0028] Further, based on the value of the number N, the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is determined, specifically:

[0029] In the S CP voltage sampling values, it is assumed that the number of CP positive phase voltage states P=12V is N1, the number of CP positive phase voltage states P=9V is N2, and the number of CP positive phase voltage states P=6V is N3;

[0030] Determine whether N1>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 12V;

[0031] If not, determine whether N2>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 9V.

[0032] If not, determine whether N3>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 6V; if not, it does not meet the CP positive phase voltage state P; wherein D is the current PWM output duty cycle.

[0033] Further, based on the voltage state values ​​corresponding to the CP positive phase voltage state P of the most recent T consecutive cycles, the voltage state value of the current CP positive phase voltage state P is updated, specifically: if the CP positive phase voltage states P of the most recent T consecutive cycles are all the same voltage state value, the current CP positive phase voltage state P is updated to the voltage state value;

[0034] Based on the voltage state values ​​corresponding to the CP negative phase voltage state Q of the most recent T consecutive cycles, the voltage state value of the current CP negative phase voltage state Q is updated. Specifically, if the CP negative phase voltage state Q of the most recent T consecutive cycles are all the same voltage state value, the current CP negative phase voltage state Q is updated to the voltage state value.

[0035] Furthermore, based on the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q, as well as the PWM output condition, the current charging connection state is determined, and the existence of the diode is verified, specifically:

[0036] If the CP positive phase voltage state P is 12V, the CP negative phase voltage state Q is 0V, and no PWM signal is currently output, it means that the charging device is not connected;

[0037] If the CP positive phase voltage state P is 9V or 6V, the CP negative phase voltage state Q is 0V, and no PWM signal is currently output, it means that the charging device is connected but charging is not started;

[0038] If the CP positive phase voltage state P is 9V or 6V, the CP negative phase voltage state Q is -9V or -6V, and the current output PWM signal indicates that the charging device is connected and charging is started;

[0039] If the CP positive phase voltage state P is 6V, the CP negative phase voltage state Q is -6V, and the current output PWM signal, it means that the charging device is connected and charging;

[0040] After the charging device is connected and outputs a PWM signal, if the CP negative phase voltage state Q is -12V, it is determined that the diode exists; if the CP negative phase voltage state Q is -6V or -9V, it is determined that the diode does not exist.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The CP output circuit of the present invention includes a comparator, which converts the PWM level signal generated by the PWM output interface into a ±12V level signal, and finally outputs a PWM square wave signal; and the rise time and fall time of the PWM square wave signal are extremely short, which can respond to the control command more quickly. At the same time, the PWM square wave is more standardized, and for the CP collection at the pile end or the vehicle end, the identification of the CP line voltage state and the CP duty cycle will be more accurate.

[0043] (2) The CP acquisition circuit of the present invention uses a voltage-dividing resistor to obtain the ADC acquisition interface voltage of the main controller MCU, and then calculates the CP voltage to determine the voltage state of the CP output interface; there is no need to set up two sets of positive and negative CP detection circuits, and the CP positive phase voltage and the CP negative phase voltage can be directly obtained. The circuit structure is simple, the device cost is low, and the method for obtaining the CP voltage is simple and accurate, which reduces the performance requirements for the main controller MCU and improves the accuracy of voltage detection.

[0044] (3) The CP acquisition method of the present invention can solve the problem that the variable duty cycle square wave is easily affected by the square wave rising edge, falling edge burrs and some noise, resulting in inaccurate acquisition, thereby improving the accuracy of judging the vehicle connection status and enhancing the anti-interference ability.

[0045] Other features and advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the control and guidance circuit of an AC charging pile in an embodiment of the present invention;

[0047] Figure 2 This is a circuit diagram of the AC charging pile control guide CP in an embodiment of the present invention;

[0048] Figure 3 This is a timing diagram of charging connection at detection point 1 when an AC charging pile is connected to an electric vehicle in an embodiment of the present invention;

[0049] Figure 4 This is a timing diagram of charging connection at detection point 1 when an AC charging pile is connected to an electric vehicle simulator in an embodiment of the present invention;

[0050] Figure 5 Schematic diagram of the process of the AC charging pile control guidance CP collection method in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0052] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0053] Embodiment 1

[0054] In one or more embodiments, an AC charging pile control guide CP circuit is disclosed, firstly combining Figure 1 The principle of the AC charging pile control guidance circuit is explained, wherein the power supply equipment refers to the AC charging pile, and the electric vehicle is the charging equipment. The AC charging pile control guidance CP circuit of this embodiment is integrated in Figure 1 In the power supply control device in the power supply equipment shown.

[0055] Combination Figure 1 , K1, ... KN are AC contactors / relays inside the power supply equipment, S1 is a PWM signal switching switch inside the power supply equipment, R1 is a control pilot circuit resistor inside the power supply equipment, S2 is a control pilot circuit switch inside the electric vehicle, and R2, R3 are control pilot circuit resistors inside the electric vehicle. When the vehicle and the power supply equipment are fully connected, the charging equipment (vehicle) completes self-test, and is in a state where charging is allowed, S2 is closed, S3 is linked to the push button on the vehicle plug, and when the button is pressed to contact the mechanical lock, S3 is in a disconnected state. When the charging equipment and the power supply equipment are fully connected, S3 is in a connected state. The output voltage of the power supply equipment CP is 12V. When the charging equipment and the power supply equipment are fully connected, due to the voltage division of the resistor R3, the voltage of the detection point 1 on the CP connection line becomes 9V. When the vehicle S2 is closed, the voltage division resistor R2 is added, and the voltage of the detection point 1 on the CP connection line becomes 6V. The power supply equipment can determine the current connection state by collecting the voltage state of the detection point 1, thereby determining whether to control S1 to close to output PWM and switch the K1, ... KN relay states.

[0056] Combination Figure 2 The AC charging pile control and guidance CP circuit of this embodiment specifically includes: a main controller MCU (hereinafter referred to as MCU), a CP output circuit and a CP acquisition circuit.

[0057] Among them, the control circuit board composed of MCU and its peripheral circuits is Figure 1 The power supply control device in the power supply equipment. MCU is the controller inside the AC charging pile, with PWM output interface and ADC acquisition interface; it cooperates with CP output circuit and CP acquisition circuit to realize the control guidance function of the AC charging pile.

[0058] The CP output circuit includes a comparator, the comparator input end is connected to the PWM output interface of the MCU, and the output end is connected to the CP output interface; the PWM output interface of the MCU is used to generate a 3.3V level signal, and the comparator is used to convert the 3.3V PWM level signal into a ±12V level signal.

[0059] The specific structure of the CP output circuit of this embodiment is as follows: a resistor R1 is connected in series between the positive input terminal of the comparator and the PWM output interface of the MCU, a pull-up resistor R2 and a grounding resistor R3 are connected to the negative input terminal of the comparator, the positive power input terminal +Vs of the comparator is connected to a +12V precision reference voltage, and the negative power input terminal -Vs is connected to a -12V precision reference voltage. A parallel branch consisting of a resistor R4 and a resistor R5 in parallel is connected between the output terminal of the comparator and the CP output interface; and a transient voltage suppression diode is connected between the CP output interface and the ground line.

[0060] The working principle of the CP output circuit of this embodiment is as follows: MCU controls its PWM output interface to output a square wave signal with a high level of 3.3V, a low level of 0V, and a frequency of 1khz. Figure 1 After the comparator circuit shown, the high level will be converted to +12V, the low level will be converted to -12V, the frequency and duty cycle remain unchanged, that is, the PWM signal that meets the standard requirements. The ±12V voltage accuracy is determined by the comparator's positive power input terminal +Vs and negative power input terminal -Vs. The circuit uses a precision reference voltage to achieve the purpose of improving output accuracy. The main function of the transient voltage suppression diode is to protect electronic circuits from transient overvoltages, such as surges, lightning overvoltages, etc. The equivalent resistance of the parallel branch formed by the parallel connection of resistors R4 and R5 is 1kΩ, which serves as Figure 2 The equivalent resistor R1 in the AC charging pile control pilot circuit schematic diagram is shown.

[0061] In this implementation example, the comparator may be SGM8778E-1, and the CP output circuit formed by the comparator finally outputs a PWM square wave signal with extremely short rise and fall times and high voltage accuracy.

[0062] The CP acquisition circuit includes a voltage-dividing resistor circuit, which converts the CP output signal from a voltage range of -12V to +12V to a voltage within the MCU acquisition range.

[0063] The specific structure of the CP acquisition circuit of this embodiment is as follows: two 100kΩ voltage-dividing resistors R6 and R7 are connected in series between the CP output interface and the ADC acquisition interface of the MCU, and a parallel branch formed by connecting resistors R8, R9 and R10 in parallel is connected between the ADC acquisition interface and the 3.3V precision reference voltage to play a voltage-dividing role, and the resistance values ​​of resistors R8, R9 and R10 are all 100kΩ. A parallel branch formed by connecting resistors R11 and R12 in parallel is connected between the ADC acquisition interface and the ground line to play a voltage-dividing role, and the resistance values ​​of resistors R11 and R12 are all 100kΩ; a capacitor C3 is also connected between the ADC acquisition interface and the ground line to play a filtering role.

[0064] In order to improve the acquisition accuracy, the above-mentioned voltage divider resistors all use resistors with a precision of 1 / 1000.

[0065] The CP acquisition circuit of this embodiment converts the -12V to +12V voltage output on the CP line into a voltage within the range of 0V to 3.3V through a voltage divider resistor, and the ADC acquisition range of the MCU is 0V to 3.3V. The ADC acquisition interface voltage V collected by the MCU is adc , the output voltage V on the CP line can be inferred cp .

[0066] Based on Kirchhoff's law, the CP voltage is calculated according to the ADC acquisition interface voltage of the main controller MCU, specifically:

[0067] V cp =a*V adc -b*V ref ;

[0068] Among them, V cp is the CP voltage, V adc is the voltage of the ADC acquisition interface of the main controller MCU, a and b are the calculated proportional coefficients, V ref It is the reference voltage of MCU.

[0069] As a specific implementation, the CP voltage calculation formula obtained in this embodiment is specifically:

[0070] V cp =11*V adc -6*3.3.

[0071] After obtaining the CP voltage, the voltage state of the CP output interface can be determined; according to the voltage state of the CP output interface, the charging state of the AC charging pile and the existence of the diode can be determined.

[0072] Figure 3This is the charging connection timing diagram of detection point 1 when the AC charging pile is connected to the electric vehicle, which includes the CP level signal changes when the AC charging pile and the electric vehicle are connected in different states. The AC charging pile determines the specific charging state by collecting the CP voltage state of detection point 1:

[0073] (1) When the charging device is not connected, the CP positive phase voltage state P is 12V, the CP negative phase voltage state Q is 0V; no PWM signal is output;

[0074] (2) When the charging device is connected but not started, the CP positive phase voltage state P is 9V or 6V, and the CP negative phase voltage state Q is 0V; no PWM signal is output;

[0075] (3) When the charging device is connected and charging is started, the CP voltage state P is 9V or 6V, and the CP negative phase voltage state Q is -12V; a PWM signal is output;

[0076] (4) The charging device is connected. When charging, the CP voltage state P is 6V, and the CP negative phase voltage state Q is -12V; the PWM signal is output;

[0077] Other states outside the above voltage state range are CP voltage error states.

[0078] Reference Figure 4 This is the charging connection timing diagram of detection point 1 when the AC charging pile is connected to the electric vehicle simulator, which includes the CP level signal changes when the connection status of the AC charging pile and the electric vehicle simulator is different:

[0079] (1) When the charging device is not connected, the CP positive phase voltage state P is 12V, the CP negative phase voltage state Q is 0V; no PWM signal is output;

[0080] (2) When the charging device is connected but not started, the CP positive phase voltage state P is 9V or 6V, and the CP negative phase voltage state Q is 0V; no PWM signal is output;

[0081] (3) When the charging device is connected and charging is started, the CP positive phase voltage state P is 9V or 6V, and the CP negative phase voltage state Q is -9V or -6V; a PWM signal is output;

[0082] (4) The charging device is connected. When charging, the CP positive phase voltage state P is 6V, and the CP negative phase voltage state Q is -6V; the PWM signal is output;

[0083] Other states outside the above voltage state range are CP voltage error states.

[0084] Figure 5 A schematic diagram of the AC charging pile control guidance CP acquisition method is given. First of all, it should be explained that:

[0085] The CP positive phase voltage state P means that the CP positive phase voltage is within one of the nominal values ​​of 6V, 9V or 12V when the PWM signal is output or not output;

[0086] The CP negative phase voltage state Q means that when a PWM signal is output, the CP negative phase voltage is within one of the nominal values ​​of -6V, -9V or -12V.

[0087] As an example, the nominal value range of 6V refers to the voltage range of 5 to 7V; the nominal value range of 9V refers to the voltage range of 8 to 10V; the nominal value range of 12V refers to the voltage range of 11 to 13V; similarly, the nominal value range of -6V refers to the voltage range of -5 to -7V; the nominal value range of -9V refers to the voltage range of -8 to -10V; the nominal value range of -12V refers to the voltage range of -11 to -13V.

[0088] The AC charging pile control guidance CP collection method of this embodiment specifically includes the following process:

[0089] S1: In one PWM cycle, the CP voltage is sampled S times continuously.

[0090] In this embodiment, the ADC acquisition of the MCU adopts a continuous sampling and continuous conversion mode, the sampling time interval is set to 20us, and 50 samples are continuously sampled each time, that is, 50 samples are sampled within one PWM cycle, that is, S=50.

[0091] S2: Determine the number N of CP voltage sampling values ​​that meet the CP positive phase voltage state P and the number M of CP voltage sampling values ​​that meet the CP negative phase voltage state Q among the S CP voltage sampling values.

[0092] Specifically, after each acquisition cycle, i.e., 50 sampling points, data processing is performed to compare and determine the number N of CP voltage sampling values ​​that meet the CP positive phase voltage state P and the number M of CP voltage sampling values ​​that meet the CP negative phase voltage state Q in the 50 data.

[0093] As a specific example, among the S CP voltage sampling values, it is assumed that the number of CP positive phase voltage states P=12V is N1, the number of CP positive phase voltage states P=9V is N2, and the number of CP positive phase voltage states P=6V is N3; it is assumed that the number of CP negative phase voltage states Q state=-12V is M1, the number of CP negative phase voltage states Q state=-9V is M2, and the number of CP negative phase voltage states Q state=-6V is M3.

[0094] S3: Based on the values ​​of the quantities N and M, voltage state values ​​and PWM output conditions corresponding to the CP positive phase voltage state P and the CP negative phase voltage state Q in the current PWM cycle are determined.

[0095] Specifically, for the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle:

[0096] Determine whether N1>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 12V;

[0097] If not, determine whether N2>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 9V.

[0098] If not, determine whether N3>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 6V; if not, it does not meet the CP positive phase voltage state P; wherein D is the current PWM output duty cycle.

[0099] For the voltage state value corresponding to the CP negative phase voltage state Q in the current PWM cycle:

[0100] Determine whether M1>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP negative phase voltage state Q in the current PWM cycle is -12V;

[0101] If not, determine whether M2>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP negative phase voltage state Q in the current PWM cycle is -9V;

[0102] If not satisfied, determine whether M3>D*50*50% is satisfied. If satisfied, determine that the voltage state value corresponding to the CP negative phase voltage state Q in the current PWM cycle is -6V; if not satisfied, it does not meet the CP negative phase voltage state Q; wherein D is the current PWM output duty cycle.

[0103] At the same time, it records whether the PWM signal is output. The specific judgment method can be selected according to the actual situation. For example, it can be judged whether the PWM signal is output based on whether the MCU executes the PWM output or stop output command. It can also be determined whether the PWM signal is output by detecting whether the collected voltage on the CP line has positive and negative voltage states and the duty cycle within a PWM cycle.

[0104] S4: based on the voltage state values ​​corresponding to the CP positive phase voltage state P and the CP negative phase voltage state Q of the most recent T consecutive cycles, update the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q;

[0105] Specifically, the CP positive phase voltage state P and the CP negative phase voltage state Q of the most recent T consecutive cycles (T=5 times in this example) are taken;

[0106] If the CP positive phase voltage state P of the most recent T consecutive cycles is the same voltage state value, then the current CP positive phase voltage state P is updated to the voltage state value; for example: if the CP positive phase voltage state P in the most recent T consecutive cycles is within the nominal value of 6V, then the current CP positive phase voltage state P is updated to 6V.

[0107] Similarly, if the CP negative phase voltage states Q of the most recent T consecutive cycles are all the same voltage state value, the current CP negative phase voltage state Q is updated to the voltage state value.

[0108] S5: Based on the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q, and the PWM output condition, determine the current charging connection state, and verify the existence of the diode.

[0109] Specifically, if the CP positive phase voltage state P is 12V, the CP negative phase voltage state Q is 0V, and no PWM signal is currently output, it means that the charging device is not connected;

[0110] If the CP positive phase voltage state P is 9V or 6V, the CP negative phase voltage state Q is 0V, and no PWM signal is currently output, it means that the charging device is connected but charging is not started;

[0111] If the CP positive phase voltage state P is 9V or 6V, the CP negative phase voltage state Q is -9V or -6V, and the current output PWM signal, it means that the charging device has been connected and charging is started;

[0112] If the CP positive phase voltage state P is 6V, the CP negative phase voltage state Q is -6V, and the current output PWM signal, it means that the charging device is connected and charging;

[0113] After the charging device is connected and outputs a PWM signal, if the CP negative phase voltage state Q is -12V, it is determined that the diode exists; if the CP negative phase voltage state Q is -6V or -9V, it is determined that the diode does not exist.

[0114] The CP voltage acquisition circuit of this embodiment has a simple structure and low device cost. The method for acquiring the CP voltage is simple and accurate, which reduces the performance requirements for the main controller MCU and improves the accuracy of voltage detection.

[0115] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. An AC charging pile control and guidance CP circuit, characterized in that: include: Main controller MCU, CP output circuit and CP acquisition circuit; The CP output circuit includes a comparator, the comparator input end is connected to the PWM output interface of the main controller MCU, and is used to convert the PWM level signal into a voltage signal of a set size; the comparator output end is connected to the CP output interface; the CP output interface is connected to the CP acquisition circuit; The CP acquisition circuit includes: an ADC acquisition interface of a main controller MCU is connected to a CP output interface via a resistor R6 and a resistor R7 connected in series in sequence; A voltage-dividing resistor is connected between the ADC acquisition interface of the main controller MCU and the reference voltage; a voltage-dividing resistor and a filter capacitor are respectively connected between the ADC acquisition interface of the main controller MCU and the ground line.

2. The AC charging pile control guide CP circuit according to claim 1, characterized in that: The voltage divider resistor connected between the ADC acquisition interface of the main controller MCU and the reference voltage is specifically: a parallel branch composed of a resistor R8, a resistor R9 and a resistor R10 connected in parallel.

3. The AC charging pile control and guidance CP circuit according to claim 1, characterized in that: The voltage-dividing resistor connected between the ADC acquisition interface of the main controller MCU and the ground line is specifically: a parallel branch formed by a resistor R11 and a resistor R12 connected in parallel.

4. The AC charging pile control and guidance CP circuit according to claim 1, characterized in that: A resistor R1 is connected in series between the positive input end of the comparator and the PWM output interface of the main controller MCU; a pull-up resistor R2 and a grounding resistor R3 are respectively connected to the negative input end of the comparator; a parallel branch composed of a resistor R4 and a resistor R5 in parallel is connected between the output end of the comparator and the CP output interface; a transient voltage suppression diode is connected in series between the CP output interface and the ground line.

5. The AC charging pile control and guidance CP circuit according to claim 1, characterized in that: The ADC of the main controller MCU collects the interface voltage and calculates the CP voltage to determine the voltage state of the CP output interface. The charging state of the AC charging pile and the existence of the diode are determined based on the voltage state of the CP output interface.

6. An AC charging pile control and guidance CP circuit as claimed in claim 5, characterized in that: According to the ADC acquisition interface voltage of the main controller MCU, the CP voltage is calculated as follows: V cp =a*V adc -b*V ref ; Among them, V cp is the CP voltage, V adc is the voltage of the ADC acquisition interface of the main controller MCU, a and b are the proportional coefficients, V ref It is the reference voltage of MCU.

7. A method for collecting CP of an AC charging pile control guide, characterized in that: include: In one PWM cycle, the CP voltage is sampled S times continuously; Determine the number N of CP voltage sampling values ​​that meet the CP positive phase voltage state P, and the number M of CP voltage sampling values ​​that meet the CP negative phase voltage state Q among the S CP voltage sampling values; Determine the voltage state value and PWM output status corresponding to the CP positive phase voltage state P and the CP negative phase voltage state Q in the current PWM cycle based on the values ​​of the quantities N and M; Based on the voltage state values ​​corresponding to the CP positive phase voltage state P and the CP negative phase voltage state Q of the most recent T consecutive cycles, the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q are updated; wherein S and T are both set positive integers; Based on the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q, as well as the PWM output condition, the current charging connection state is determined, and the existence of the diode is verified; The CP positive phase voltage state P refers to the case where the CP positive phase voltage is within one of the nominal values ​​of 6V, 9V or 12V when the PWM signal is output or not output; The CP negative phase voltage state Q means that when a PWM signal is output, the CP negative phase voltage is within one of the nominal values ​​of -6V, -9V or -12V.

8. The AC charging pile control guidance CP acquisition method according to claim 7, characterized in that: Based on the value of the quantity N, the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is determined as follows: In the S CP voltage sampling values, it is assumed that the number of CP positive phase voltage states P=12V is N1, the number of CP positive phase voltage states P=9V is N2, and the number of CP positive phase voltage states P=6V is N3; Determine whether N1>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 12V; If not, determine whether N2>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 9V. If not, determine whether N3>D*50*50% is satisfied. If so, determine that the voltage state value corresponding to the CP positive phase voltage state P in the current PWM cycle is 6V; if not, it does not meet the CP positive phase voltage state P; wherein D is the current PWM output duty cycle.

9. The AC charging pile control guidance CP acquisition method according to claim 7, characterized in that: Based on the voltage state values ​​corresponding to the CP positive phase voltage state P of the most recent T consecutive cycles, the voltage state value of the current CP positive phase voltage state P is updated, specifically: if the CP positive phase voltage states P of the most recent T consecutive cycles are all the same voltage state value, the current CP positive phase voltage state P is updated to the voltage state value; Based on the voltage state values ​​corresponding to the CP negative phase voltage state Q of the most recent T consecutive cycles, the voltage state value of the current CP negative phase voltage state Q is updated. Specifically, if the CP negative phase voltage state Q of the most recent T consecutive cycles are all the same voltage state value, the current CP negative phase voltage state Q is updated to the voltage state value.

10. The AC charging pile control guidance CP acquisition method according to claim 7, characterized in that: Based on the voltage state values ​​of the current CP positive phase voltage state P and the CP negative phase voltage state Q, as well as the PWM output condition, the current charging connection state is determined and the existence of the diode is verified, specifically: If the CP positive phase voltage state P is 12V, the CP negative phase voltage state Q is 0V, and no PWM signal is currently output, it means that the charging device is not connected; If the CP positive phase voltage state P is 9V or 6V, the CP negative phase voltage state Q is 0V, and no PWM signal is currently output, it means that the charging device is connected but charging is not started; If the CP positive phase voltage state P is 9V or 6V, the CP negative phase voltage state Q is -9V or -6V, and the current output PWM signal indicates that the charging device is connected and charging is started; If the CP positive phase voltage state P is 6V, the CP negative phase voltage state Q is -6V, and the current output PWM signal, it means that the charging device is connected and charging; After the charging device is connected and outputs a PWM signal, if the CP negative phase voltage state Q is -12V, it is determined that the diode exists; if the CP negative phase voltage state Q is -6V or -9V, it is determined that the diode does not exist.

Images