A control and guidance CP circuit and CP acquisition method for AC charging piles

Abstract

This invention discloses a CP control and guidance circuit and CP acquisition method for AC charging piles, comprising: a main controller MCU, a CP output circuit, and a CP acquisition circuit; the CP output circuit includes a comparator, the input of which is connected to the PWM output interface of the main controller MCU, for converting the PWM level signal into a voltage signal of a set magnitude; the output of the comparator is connected to the CP output interface; the CP output interface is connected to the CP acquisition circuit; 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; a voltage divider resistor is connected between the ADC acquisition interface of the main controller MCU and a reference voltage; a voltage divider resistor and a filter capacitor are connected between the ADC acquisition interface of the main controller MCU and ground. The CP voltage acquisition method of this invention is simple and accurate, reduces the performance requirements of the main controller MCU, and improves the accuracy of voltage detection.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle charging control technology, and in particular to an AC charging pile control and guidance circuit (CP) and a CP acquisition method. Background Technology

[0002] The statements in this section are merely 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, with AC charging piles gaining a foothold in the market due to their advantages of low price, small size, and simple installation. According to relevant standards for electric vehicle conductive charging systems, there are specific requirements for the control and guidance functions of AC charging piles, including the parameters and control logic of the control and guidance circuit, the voltage at detection point 1 and corresponding charging process status monitoring, and diode presence detection. 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 guide circuit; if diode D1 is detected, it means that the connected device is an electric vehicle or an electric vehicle simulator.

[0005] (2) When the AC charging pile charges the 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 existing technologies, optocouplers and operational amplifiers are often used to implement the control and guidance output circuit. The CP detection circuit is composed of resistors, capacitors, operational amplifiers, etc. To meet the requirements of relevant standards, two sets of positive and negative CP detection circuits are usually required, which makes the circuit design more complex and costly. Summary of the Invention

[0007] To address the aforementioned issues, this invention proposes an AC charging pile control and guidance CP circuit and CP acquisition method, which simplifies the circuit while enabling effective control and monitoring of the CP output voltage of the AC charging pile, and simultaneously saves resources and costs for the AC charging pile controller.

[0008] In some implementations, 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 input of the comparator is connected to the PWM output interface of the main controller MCU, which is used to convert the PWM level signal into a voltage signal of a set magnitude. The output of the comparator 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; a voltage divider resistor is connected between the ADC acquisition interface of the main controller MCU and the reference voltage; a voltage divider resistor and a filter capacitor are connected between the ADC acquisition interface of the main controller MCU and the ground wire, respectively.

[0012] Furthermore, 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 resistors R8, R9 and R10 connected in parallel.

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

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

[0015] Furthermore, based on the ADC acquisition interface voltage of the main controller MCU, the CP voltage is calculated to determine the voltage status of the CP output interface; based on the voltage status of the CP output interface, the charging status of the AC charging pile and the presence of the diode are determined.

[0016] Furthermore, based on the ADC acquisition interface voltage of the main controller MCU, the CP voltage is calculated as follows:

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

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

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

[0020] A method for acquiring CP (Concurrent Probe) data for AC charging pile control guidance includes:

[0021] Within one PWM cycle, the CP voltage is sampled S times consecutively;

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

[0023] Based on the values ​​of the quantities N and M, determine the voltage state values ​​and PWM output status corresponding to the positive phase voltage state P and the negative phase voltage state Q of CP in the current PWM cycle.

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

[0025] Based on the current voltage state values ​​of the positive phase voltage state P and the negative phase voltage state Q of CP, and the PWM output status, determine the current charging connection status and verify the existence of the diode;

[0026] Among them, the CP positive phase voltage state P refers to the CP positive phase voltage being within one of the nominal values ​​of 6V, 9V or 12V, whether the PWM signal is output or not.

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

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

[0029] In the S CP voltage sampling values, assume 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 it is satisfied, determine that the voltage state value corresponding to the positive phase voltage state P of CP in the current PWM cycle is 12V.

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

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

[0033] Furthermore, based on the voltage state values ​​corresponding to the most recent consecutive T cycles of CP positive phase voltage state P, the voltage state value of the current CP positive phase voltage state P is updated. Specifically, if the most recent consecutive T cycles of CP positive phase voltage state P are all the same voltage state value, then 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 states Q of the most recent consecutive T cycles, update the voltage state value of the current CP negative phase voltage state Q. Specifically, if the CP negative phase voltage states Q of the most recent consecutive T cycles are all the same voltage state value, then update the current CP negative phase voltage state Q to the voltage state value.

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

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

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

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

[0039] If the positive phase voltage P of the CP is 6V and the negative phase voltage Q is -6V, and the current output PWM signal indicates that the charging device is connected and charging is in progress;

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

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[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. The rise time and fall time of the PWM square wave signal are extremely short, which can respond to control commands faster. At the same time, the PWM square wave is more standard, which can more accurately identify the CP line voltage status and CP duty cycle for CP acquisition at the pile end or vehicle end.

[0043] (2) The CP acquisition circuit of the present invention uses a voltage divider 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 positive phase voltage and negative phase voltage of CP can be obtained directly. The circuit structure is simple, the component cost is low, the method of obtaining CP voltage is simple and accurate, the performance requirements of the main controller MCU are reduced, and the accuracy of voltage detection is improved.

[0044] (3) The CP acquisition method of the present invention can solve the problem that the square wave with variable duty cycle is easily affected by the rising edge and falling edge of the square wave and some noise, which leads to inaccurate acquisition, improves the accuracy of judging the vehicle connection status and enhances the anti-interference ability.

[0045] Other features and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the AC charging pile control and guidance circuit 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 the 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 the charging connection at detection point 1 when the AC charging pile is connected to the electric vehicle simulator in an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram of the AC charging pile control guidance CP acquisition method in an embodiment of the present invention. Detailed Implementation

[0051] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0052] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0053] Example 1

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

[0055] Combination Figure 1 K1, ... KN are internal AC contactors / relays of the power supply equipment; S1 is an internal PWM signal switching switch of the power supply equipment; R1 is an internal control guide circuit resistor of the power supply equipment; S2 is an internal control guide circuit switch of the electric vehicle; and R2 and R3 are internal control guide circuit resistors of the electric vehicle. When the vehicle and power supply equipment are fully connected, and the charging equipment (vehicle) has completed its self-test and is in a charging-allowed state, S2 closes. S3 is linked to the push-button on the vehicle plug. Pressing the button engages the mechanical lock, and S3 is in the open state. When the charging equipment and power supply equipment are fully connected, S3 is in the connected state. The power supply equipment's CP output voltage is 12V. When the charging equipment and power supply equipment are fully connected, due to the voltage division by resistor R3, the voltage at detection point 1 on the CP connection line becomes 9V. When vehicle S2 is closed, the voltage dividing resistor R2 is added, and the voltage at detection point 1 on the CP connection line becomes 6V. By collecting the voltage status at detection point 1, the power supply equipment can determine the current connection status, thereby determining whether to control S1 to close to output PWM and switch the states of relays K1, ... KN.

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

[0057] The control circuit board, composed of the MCU and its peripheral circuits, is called the MCU. Figure 1 The power supply control device is located within the power supply equipment of the AC charging pile. The MCU is the internal controller of the AC charging pile, equipped with a PWM output interface and an ADC acquisition interface; it works in conjunction with the CP output circuit and CP acquisition circuit to realize the control and guidance function of the AC charging pile.

[0058] The CP output circuit includes a comparator. The input of the comparator is connected to the PWM output interface of the MCU, and the output 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 in 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 supply input terminal +Vs of the comparator is connected to a +12V precision reference voltage; the negative power supply input terminal -Vs is connected to a -12V precision reference voltage; a parallel branch consisting of resistors R4 and R5 is connected between the comparator output terminal and the CP output interface; a transient voltage suppressor diode is connected between the CP output interface and the ground wire.

[0060] The working principle of the CP output circuit in this embodiment is as follows: The 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. This signal is then processed... Figure 1 After the comparator circuit shown, the high level will be converted to +12V, and the low level will be converted to -12V, while the frequency and duty cycle remain unchanged, thus providing a PWM signal that meets standard requirements. The ±12V voltage accuracy is determined by the comparator's positive power supply input terminal +Vs and negative power supply input terminal -Vs. The circuit uses a precision reference voltage to improve output accuracy. The main function of the transient voltage suppressor diode is to protect electronic circuits from transient overvoltages, such as power surges and lightning overvoltages. The parallel branch formed by resistors R4 and R5 has an equivalent resistance of 1kΩ, serving as... Figure 2 The equivalent resistance R1 in the schematic diagram of the AC charging pile control and guidance circuit shown.

[0061] In this implementation example, the comparator can be the SGM8778E-1. The CP output circuit constructed from it 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 divider resistor circuit, which converts the CP output signal from a voltage range of -12V to +12V into a voltage within the MCU's acquisition range.

[0063] The specific structure of the CP acquisition circuit in this embodiment is as follows: Two 100kΩ voltage divider resistors, R6 and R7, are connected in series between the CP output interface and the MCU's ADC acquisition interface. A parallel branch consisting of resistors R8, R9, and R10 is connected between the ADC acquisition interface and the 3.3V precision reference voltage, serving as a voltage divider. The resistance values ​​of resistors R8, R9, and R10 are all 100kΩ. A parallel branch consisting of resistors R11 and R12 is connected between the ADC acquisition interface and ground, also serving as a voltage divider. The resistance values ​​of resistors R11 and R12 are both 100kΩ. A capacitor C3 is also connected between the ADC acquisition interface and ground for filtering.

[0064] To improve the accuracy of data acquisition, all of the voltage divider resistors mentioned above are resistors with a precision of 1 / 1000.

[0065] In this embodiment, the CP acquisition circuit converts the -12V to +12V voltage output on the CP line into a voltage within the range of 0V to 3.3V using voltage divider resistors. The MCU's ADC acquisition range is 0V to 3.3V. The voltage V acquired by the MCU through the ADC acquisition interface is... adc The output voltage V on the CP line can be deduced from this. cp .

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

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

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

[0069] As a specific implementation method, the formula for calculating the CP voltage obtained in this embodiment is as follows:

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

[0071] Once the CP voltage is obtained, the voltage status of the CP output interface can be determined; based on the voltage status of the CP output interface, the charging status of the AC charging pile and the presence of the diode can be determined.

[0072] Figure 3The timing diagram for charging connection at detection point 1 when an electric vehicle is connected to an AC charging station includes the changes in the CP level signal when the AC charging station and the electric vehicle are in different connection states. The AC charging station determines the specific charging state by collecting the CP voltage status at detection point 1.

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

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

[0075] (3) When the charging equipment 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; output PWM signal;

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

[0077] Any state outside the above voltage state range is a CP voltage error state.

[0078] Reference Figure 4 This is a timing diagram of the charging connection at detection point 1 when the AC charging pile is connected to the electric vehicle simulator. It includes the changes in the CP level signal 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 positive phase voltage P of CP is 12V and the negative phase voltage Q of CP is 0V; no PWM signal is output.

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

[0081] (3) When the charging equipment is connected and charging is in progress, the positive phase voltage P of CP is 9V or 6V, and the negative phase voltage Q of CP is -9V or -6V; output PWM signal;

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

[0083] Any state outside the above voltage state range is a CP voltage error state.

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

[0085] The CP positive phase voltage state P refers to the CP positive phase voltage being within one of the nominal values ​​of 6V, 9V, or 12V, whether or not a PWM signal is output;

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

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

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

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

[0090] In this embodiment, the MCU's ADC acquisition adopts a continuous sampling and continuous conversion mode, with a sampling time interval set to 20us. Each sampling is 50 samples, that is, 50 samples are taken within one PWM cycle, i.e., S=50.

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

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

[0093] As a specific example, in the S CP voltage sampling values, assume 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; assume that the number of CP negative phase voltage states Q=-12V is M1, the number of CP negative phase voltage states Q=-9V is M2, and the number of CP negative phase voltage states Q=-6V is M3.

[0094] S3: Determine the voltage state values ​​and PWM output status corresponding to the positive phase voltage state P and the negative phase voltage state Q of CP in the current PWM cycle based on the values ​​of the quantities N and M.

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

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

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

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

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

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

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

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

[0103] Simultaneously record whether a PWM signal is output. The specific determination method can be selected according to the actual situation. For example, it can be determined whether a PWM signal is output based on whether the MCU executes a command to output or stop output. Alternatively, it can be determined whether a PWM signal is output by detecting whether the voltage on the CP line has both positive and negative voltage states and the duty cycle within a PWM cycle.

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

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

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

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

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

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

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

[0111] If the positive phase voltage P of the CP is 9V or 6V, the negative phase voltage Q of the CP is -9V or -6V, and the current output PWM signal indicates that the charging device is connected and charging has started.

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

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

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

[0115] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this 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 without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A control and guidance CP circuit for an AC charging pile, characterized in that, include: Main controller MCU, CP output circuit and CP acquisition circuit; The CP output circuit includes a comparator. The input of the comparator is connected to the PWM output interface of the main controller MCU, which is used to convert the PWM level signal into a voltage signal of a set magnitude. The output of the comparator is connected to the CP output interface. The CP output interface is connected to the CP acquisition circuit. 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; a voltage divider resistor is connected between the ADC acquisition interface of the main controller MCU and the reference voltage; a parallel branch consisting of resistors R11 and R12 is connected between the ADC acquisition interface of the main controller MCU and the ground line to serve as a voltage divider; a capacitor C3 is also connected between the ADC acquisition interface and the ground line to serve as a filter. A resistor R1 is connected in series between the positive input terminal of the comparator and the PWM output interface of the main controller MCU; a pull-up resistor R2 and a grounding resistor R3 are connected to the negative input terminal of the comparator; a parallel branch consisting of resistors R4 and R5 is connected between the output terminal of the comparator and the CP output interface; a transient voltage suppressor diode is connected in series between the CP output interface and the ground wire. Within one PWM cycle, S consecutive CP voltage samples are performed; the number N of CP voltage samples that conform to the positive phase voltage state P and the number M of CP voltage samples that conform to the negative phase voltage state Q are determined; based on the voltage state values ​​corresponding to the positive phase voltage state P and the negative phase voltage state Q of the most recent T consecutive cycles, the voltage state values ​​of the current positive phase voltage state P and the negative phase voltage state Q are updated; where S and T are both set positive integers. Based on the current voltage state values ​​of the positive phase voltage P and the negative phase voltage Q of CP, as well as the PWM output, determine the current charging connection state and verify the existence of the diode.

2. The AC charging pile control and guidance CP circuit as described in claim 1, characterized in that, The voltage divider resistor connecting the ADC acquisition interface of the main controller MCU and the reference voltage is specifically a parallel branch consisting of resistors R8, R9 and R10 connected in parallel.

3. The AC charging pile control and guidance CP circuit as described in claim 1, characterized in that, The voltage divider resistor connecting the ADC acquisition interface of the main controller MCU to the ground line is specifically a parallel branch consisting of resistors R11 and R12 connected in parallel.

4. The AC charging pile control and guidance CP circuit as described in claim 1, characterized in that, The CP voltage is calculated based on the ADC acquisition interface voltage of the main controller MCU, thereby determining the voltage status of the CP output interface; based on the voltage status of the CP output interface, the charging status of the AC charging pile and the presence of the diode are determined.

5. The AC charging pile control and guidance CP circuit as described in claim 4, characterized in that, The CP voltage is calculated based on the ADC acquisition interface voltage of the main controller MCU, specifically as follows: V cp =a V adc -b V ref ; Among them, V cp For CP voltage, V adc The voltage at the ADC acquisition interface of the main controller MCU, where a and b are proportional coefficients, V ref This is the reference voltage for the MCU.

6. A method for acquiring control and guidance CP data for an AC charging pile, comprising an AC charging pile control and guidance CP circuit as described in any one of claims 1-5, characterized in that, include: Within one PWM cycle, the CP voltage is sampled S times consecutively; Determine the number N of CP voltage samples that meet the positive phase voltage state P and the number M of CP voltage samples that meet the negative phase voltage state Q among the S CP voltage samples; Based on the values ​​of the quantities N and M, determine the voltage state values ​​and PWM output status corresponding to the positive phase voltage state P and the negative phase voltage state Q of CP in the current PWM cycle. Based on the voltage state values ​​corresponding to the most recent consecutive T cycles of CP positive phase voltage state P and CP negative phase voltage state Q, update the voltage state values ​​of the current CP positive phase voltage state P and CP negative phase voltage state Q; where S and T are both set positive integers. Based on the current voltage state values ​​of the positive phase voltage state P and the negative phase voltage state Q of CP, and the PWM output status, determine the current charging connection status and verify the existence of the diode; Among them, the CP positive phase voltage state P refers to the CP positive phase voltage being within one of the nominal values ​​of 6V, 9V or 12V, whether the PWM signal is output or not. The CP negative phase voltage state Q refers to the CP negative phase voltage being within one of the nominal values ​​of -6V, -9V, or -12V when the PWM signal is output.

7. The AC charging pile control guidance CP acquisition method as described in claim 6, characterized in that, The voltage state value corresponding to the positive phase voltage state P of CP within the current PWM cycle is determined based on the value of the quantity N, specifically as follows: In the S CP voltage sampling values, assume 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 if N1>D 50 If 50% is satisfied, the voltage state value corresponding to the positive phase voltage state P of CP in the current PWM cycle is determined to be 12V. If not, check if N2>D is satisfied. 50 If 50% is satisfied, the voltage state value corresponding to the positive phase voltage state P of CP in the current PWM cycle is determined to be 9V. If not, check if N3>D is satisfied. 50 If 50% is satisfied, the voltage state value corresponding to the positive phase voltage state P of CP in the current PWM cycle is determined to be 6V; if not satisfied, the positive phase voltage state P of CP is not satisfied; where D is the current PWM output duty cycle.

8. The AC charging pile control guidance CP acquisition method as described in claim 6, characterized in that, Based on the voltage state values ​​corresponding to the most recent consecutive T-cycle CP positive phase voltage states P, update the voltage state value of the current CP positive phase voltage state P. Specifically, if the most recent consecutive T-cycle CP positive phase voltage states P are all the same voltage state value, then update the current CP positive phase voltage state P to the voltage state value. Based on the voltage state values ​​corresponding to the CP negative phase voltage states Q of the most recent consecutive T cycles, update the voltage state value of the current CP negative phase voltage state Q. Specifically, if the CP negative phase voltage states Q of the most recent consecutive T cycles are all the same voltage state value, then update the current CP negative phase voltage state Q to the voltage state value.

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

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