OBC vehicle end diode detection circuit

Abstract

The utility model discloses a kind of OBC car end diode detection circuit, including negative pressure sampling circuit, reverse amplification circuit and low pass filter circuit, wherein, negative pressure sampling circuit is connected with car end OBC, control guide signal and reverse amplification circuit respectively, reverse amplification circuit is connected with low pass filter circuit, low pass filter circuit is connected with the ADC pin of rear stage MCU microprocessor.The utility model detects control guide signal negative voltage, and then realizes the effective identification of car end OBC car diode, effectively improves the reliability and stability of charging pile control guide operation, with the characteristics of simple structure, high reliability, low cost.

Description

Technical Field

[0001] This utility model belongs to the field of new energy vehicle charging technology, specifically relating to an OBC vehicle-side diode detection circuit. Background Technology

[0002] The new national standard GB / T18487.1 2023, A.2.6, adds requirements for detecting the presence of diodes. During the interaction between the charging pile and the new energy vehicle, the charging pile should be able to detect the presence of the vehicle-side diode on the control guidance circuit to verify that the charging pile is connected to the new energy electric vehicle equipment rather than a load device. The control guidance signal is the communication protocol between the charging pile and the vehicle-side OBC, and is actually a ±12V pulse signal.

[0003] However, existing charging pile technology can only detect positive voltage signals of control guidance signals and ignores the detection of negative voltage signals. As a result, it cannot effectively identify the diodes built into the vehicle-side OBC, which reduces the reliability of communication between the charging pile and the vehicle-side OBC and poses certain safety risks.

[0004] Therefore, there is an urgent need for an OBC (On-Board Circuit) diode detection circuit to achieve accurate identification and judgment of the OBC diode. Utility Model Content

[0005] The purpose of this invention is to provide an OBC (On-Board Cell) terminal diode detection circuit to solve the problems mentioned in the background art. The OBC terminal diode detection circuit provided by this invention has the characteristic of accurately identifying and judging the OBC terminal diodes.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an OBC vehicle-end diode detection circuit, comprising a negative voltage sampling circuit, an inverting amplifier circuit, and a low-pass filter circuit, wherein the negative voltage sampling circuit is connected to the vehicle-end OBC, the control guidance signal, and the inverting amplifier circuit respectively, the inverting amplifier circuit is connected to the low-pass filter circuit, and the low-pass filter circuit is connected to the ADC pin of the subsequent MCU microprocessor.

[0007] Furthermore, in this invention, the control guidance signal is a ±12V pulse signal.

[0008] In order to acquire the negative voltage state of the control guidance signal, the negative voltage sampling circuit further includes a diode D1. The negative terminal of the diode D1 is connected to the vehicle end OBC and the control guidance signal, respectively. The positive terminal of the diode D1 is connected to one end of the voltage divider resistor and the filter capacitor, respectively. The other end of the voltage divider resistor is connected to the inverting amplifier circuit, and the other end of the filter capacitor is connected to the ground terminal.

[0009] To perform voltage division, the voltage divider resistors further include resistors R1 and R2, wherein one end of resistor R1 is connected to the positive terminal of diode D1, the other end of resistor R1 is connected to one end of resistor R2, and the other end of resistor R2 is connected to the inverting amplifier circuit.

[0010] To filter out noise coupled into the circuit, the filter capacitor further includes capacitor C1 and capacitor C2. One end of capacitor C1 is connected to one end of resistor R1, one end of capacitor C2 is connected to one end of resistor R2, and the other ends of capacitors C1 and C2 are respectively connected to the ground terminal.

[0011] To achieve the reverse amplification of negative voltage, the inverting amplifier circuit further includes an operational amplifier U1A, which is an LM2904 type. The non-inverting input terminal of the operational amplifier U1A is connected to the ground terminal, and the inverting input terminal of the operational amplifier U1A is connected to the negative voltage sampling circuit and one end of the resistor R3, respectively. The output terminal of the operational amplifier U1A and the other end of the resistor R3 are connected to the low-pass filter circuit, respectively.

[0012] To filter out noise coupled in the circuit and improve the sampling accuracy of the ADC, the low-pass filter circuit further includes a resistor R4 and a capacitor C3. One end of the resistor R4 is connected to the inverting amplifier circuit, and the other end of the resistor R4 is connected to one end of the capacitor C3 and the ADC pin of the subsequent MCU microprocessor. The other end of the capacitor C3 is connected to the ground terminal.

[0013] To further limit the current of the control pilot signal, a resistor R5 is connected between the negative terminal of diode D1 and the control pilot signal.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] This invention effectively identifies the vehicle-side OBC (On-Board Control) diode by detecting the negative voltage of the control guidance signal, thereby improving the reliability and stability of the charging pile control guidance operation. It features simple structure, high reliability, and low cost. Attached Figure Description

[0016] Figure 1 This is the circuit diagram of this utility model.

[0017] Figure 2 This is a circuit diagram showing the connection between this utility model and the vehicle-side OBC. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] In the description of this utility model, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are merely used for distinction in description and have no special meaning.

[0022] Example 1

[0023] Please see Figures 1-2 This embodiment provides the following technical solution: an OBC vehicle-end diode detection circuit, including a negative voltage sampling circuit, an inverting amplifier circuit and a low-pass filter circuit, wherein the negative voltage sampling circuit is connected to the vehicle-end OBC, the control guidance signal and the inverting amplifier circuit respectively, the control guidance signal is a ±12V pulse signal, the inverting amplifier circuit is connected to the low-pass filter circuit, and the low-pass filter circuit is connected to the ADC pin of the subsequent MCU microprocessor.

[0024] By adopting the above technical solution, this utility model effectively identifies the vehicle-side OBC vehicle control diode by detecting the negative voltage of the control guidance signal, thereby effectively improving the reliability and stability of the charging pile control guidance operation.

[0025] Specifically, the negative voltage sampling circuit includes diode D1, which is a negative signal unidirectional conduction diode, model SS14. The negative terminal of diode D1 is connected to the vehicle end OBC and the control guidance signal, respectively. The positive terminal of diode D1 is connected to one end of the voltage divider resistor and the filter capacitor, respectively. The other end of the voltage divider resistor is connected to the inverting amplifier circuit, and the other end of the filter capacitor is connected to the ground terminal.

[0026] By adopting the above technical solution, the negative voltage state of the control and guidance signal is collected through a negative voltage sampling circuit.

[0027] Specifically, a resistor R5 is connected between the negative terminal of diode D1 and the control signal.

[0028] By adopting the above technical solution, resistor R5 is a current-limiting resistor at the control signal input terminal, with a resistance value of 100K ohms.

[0029] Specifically, the inverting amplifier circuit includes operational amplifier U1A, which is an LM2904 type. The non-inverting input terminal of operational amplifier U1A is connected to the ground terminal. The inverting input terminal of operational amplifier U1A is connected to the negative voltage sampling circuit and one end of resistor R3, which has a resistance of 33K ohms. The output terminal of operational amplifier U1A and the other end of resistor R3 are connected to the low-pass filter circuit.

[0030] By adopting the above technical solution, the negative voltage after voltage division is converted into a positive voltage through the inverting amplifier circuit.

[0031] Specifically, the low-pass filter circuit includes resistor R4 and capacitor C3. One end of resistor R4 is connected to the inverting amplifier circuit, and the other end of resistor R4 is connected to one end of capacitor C3 and the ADC pin of the subsequent MCU microprocessor. The other end of capacitor C3 is connected to the ground terminal.

[0032] The above technical solution is used to filter out noise coupled into the circuit.

[0033] Example 2

[0034] The difference between this embodiment and embodiment 1 is that: specifically, the voltage divider resistor includes resistor R1 and resistor R2, wherein one end of resistor R1 is connected to the positive terminal of diode D1, the other end of resistor R1 is connected to one end of resistor R2, and the other end of resistor R2 is connected to the inverting amplifier circuit.

[0035] By adopting the above technical solution, resistors R1 and R2 form a voltage divider resistor, with the resistance of R1 being 100K ohms and the resistance of R2 being 33K ohms.

[0036] Example 3

[0037] The difference between this embodiment and embodiment 1 is that, specifically, the filter capacitor includes capacitor C1 and capacitor C2, wherein one end of capacitor C1 is connected to one end of resistor R1, one end of capacitor C2 is connected to one end of resistor R2, and the other ends of capacitor C1 and capacitor C2 are respectively connected to the ground terminal.

[0038] By adopting the above technical solution, capacitors C1 and C2 form a filter capacitor, which is used to filter out noise coupled in the circuit.

[0039] In this invention, if the load connected to the charging pile is a new energy vehicle, then the built-in diode D2 of the OBC is present. During the interaction between the charging pile and the new energy vehicle OBC, the internal switch S1 of the OBC is closed. When the control input signal of the CP_PWM terminal is +12V, diode D2 is forward-biased and diode D1 is reverse-biased and there is no signal output at the CP_PA output terminal. When the control input signal of the CP_PWM terminal is -12V, the built-in diode D2 of the OBC vehicle terminal is reverse-biased and diode D1 is forward-biased. After being divided by resistors R1 and R2, a voltage signal with a minimum value not exceeding -3V is obtained. The voltage signal after voltage division is input to pin 2 of the operational amplifier U1A, which converts the negative voltage signal into a positive voltage signal that can be acquired by the ADC. After being amplified by a 1x inverse ratio, a positive voltage signal with a maximum value not exceeding +3V is output. The output positive voltage signal is filtered by a low-pass filter circuit composed of resistor R4 and capacitor C3 to remove high-frequency noise, and then converted into a pulsating DC signal CP_PA, which is input to the ADC pin of the subsequent MCU microprocessor.

[0040] If the load connected to the charging pile is not a new energy vehicle, the built-in diode D2 of the vehicle-side OBC will not be present. When the CP_PWM terminal control signal input is a +12V PWM signal, the diode D1 will be reverse-biased and there will be no signal output at the CP_PA terminal. When the CP_PWM terminal control signal input is a -12V signal, due to the voltage division effect of the internal resistor R6 of the vehicle-side OBC, the input control signal will be reduced to a -9V voltage signal. After the diode D1 is forward-biased, this voltage signal will be divided by resistors R1 and R2 to obtain a voltage signal with a minimum value not exceeding -2.3V. The voltage signal after voltage division will be input to pin 2 of the operational amplifier U1A, which will convert the negative voltage signal into a positive voltage signal that can be acquired by the ADC. After being amplified by a 1x inverse ratio, the output will be a positive voltage signal with a maximum value not exceeding +2.3V. The output positive voltage signal will be filtered by a low-pass filter circuit composed of resistor R4 and capacitor C3 to remove high-frequency noise and then converted into a pulsating DC signal CP_PA, which will be input to the ADC pin of the subsequent MCU microprocessor.

[0041] Therefore, when the vehicle-side diode is present, the MCU microcontroller can collect the voltage signal in the range of 2.3-3V at the output of CP_PA, thereby determining that the load connected to the power supply equipment is a new energy vehicle; when the vehicle-side diode is not present, the MCU microcontroller can collect the voltage signal in the range of 0-2.3V at the output of CP_PA, thereby determining that the load connected to the power supply equipment is not a new energy vehicle.

[0042] In summary, this utility model effectively identifies the vehicle-side OBC (On-Board Control) diode by detecting the negative voltage of the control guidance signal, thereby improving the reliability and stability of the charging pile control guidance operation. It features simple structure, high reliability, and low cost.

[0043] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An OBC (On-Board Control) terminal diode detection circuit, characterized in that: It includes a negative voltage sampling circuit, an inverting amplifier circuit, and a low-pass filter circuit. The negative voltage sampling circuit is connected to the vehicle-end OBC, the control guidance signal, and the inverting amplifier circuit. The inverting amplifier circuit is connected to the low-pass filter circuit, and the low-pass filter circuit is connected to the ADC pin of the subsequent MCU microprocessor.

2. The OBC vehicle-end diode detection circuit according to claim 1, characterized in that: The control guidance signal is a ±12V pulse signal.

3. The OBC vehicle-end diode detection circuit according to claim 1, characterized in that: The negative voltage sampling circuit includes a diode D1. The negative terminal of the diode D1 is connected to the vehicle end OBC and the control guidance signal, respectively. The positive terminal of the diode D1 is connected to one end of the voltage divider resistor and one end of the filter capacitor, respectively. The other end of the voltage divider resistor is connected to the inverting amplifier circuit, and the other end of the filter capacitor is connected to the ground terminal.

4. The OBC vehicle-end diode detection circuit according to claim 3, characterized in that: The voltage divider resistors include resistor R1 and resistor R2. One end of resistor R1 is connected to the positive terminal of diode D1, and the other end of resistor R1 is connected to one end of resistor R2. The other end of resistor R2 is connected to the inverting amplifier circuit.

5. The OBC vehicle-end diode detection circuit according to claim 4, characterized in that: The filter capacitor includes capacitor C1 and capacitor C2. One end of capacitor C1 is connected to one end of resistor R1, one end of capacitor C2 is connected to one end of resistor R2, and the other ends of capacitor C1 and capacitor C2 are respectively connected to the ground terminal.

6. The OBC vehicle-end diode detection circuit according to claim 1, characterized in that: The inverting amplifier circuit includes an operational amplifier U1A. The non-inverting input terminal of the operational amplifier U1A is connected to the ground terminal. The inverting input terminal of the operational amplifier U1A is connected to the negative voltage sampling circuit and one end of the resistor R3, respectively. The output terminal of the operational amplifier U1A and the other end of the resistor R3 are connected to the low-pass filter circuit, respectively.

7. The OBC vehicle-end diode detection circuit according to claim 6, characterized in that: The operational amplifier U1A is an LM2904 type.

8. The OBC vehicle-end diode detection circuit according to claim 1, characterized in that: The low-pass filter circuit includes a resistor R4 and a capacitor C3. One end of the resistor R4 is connected to the inverting amplifier circuit, and the other end of the resistor R4 is connected to one end of the capacitor C3 and the ADC pin of the subsequent MCU microprocessor. The other end of the capacitor C3 is connected to the ground terminal.

9. The OBC vehicle-end diode detection circuit according to claim 3, characterized in that: A resistor R5 is connected between the negative terminal of diode D1 and the control signal.

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