Silicon controlled rectifier control circuit for electric vehicle charger

Abstract

The utility model discloses a silicon controlled rectifier control circuit for an electric vehicle charger, which relates to the technical field of electronic circuits and comprises a silicon controlled rectifier SCR1, a first rectifying and filtering unit and a silicon controlled rectifier driving control unit which are adaptively connected. The cathode of the silicon controlled rectifier SCR1 is connected with the anode of the battery, and the output cathode of the electric vehicle charger is connected with the cathode of the battery and is grounded; the first rectifying and filtering unit is used for providing conduction voltage for the silicon controlled rectifier SCR1, and the silicon controlled rectifier driving control unit is used for controlling the conduction state of the silicon controlled rectifier SCR1. The silicon controlled rectifier control circuit can further improve the safety and reliability of the charging process of the electric vehicle charger.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a thyristor control circuit for an electric vehicle charger. Background Art

[0002] Currently, many electric vehicle chargers use a design that connects a thyristor (SCR) to the negative output electrode to prevent battery backflow and reverse connection. However, this design results in isolation between the negative electrode of the charger and the negative electrode of the battery. For chargers with communication functions, when the battery is connected, if the thyristor has not yet turned on, the ground connection will be cut off, thereby hindering the mutual recognition and coordination between the charger and the battery management system (BMS), and ultimately affecting normal charging. In addition, placing the thyristor on the negative side will also increase the power consumption of the trigger circuit, and in standby mode, a certain voltage will remain at the output end of the charger, reducing the safety and reliability of charging. Utility Model Content

[0003] In response to the above problems and technical requirements, the applicant has proposed a thyristor control circuit for an electric vehicle charger.

[0004] The technical solution of the utility model is as follows:

[0005] A thyristor control circuit for an electric vehicle charger includes an adaptively connected thyristor SCR1, a first rectifier and filter unit, and a thyristor drive control unit, wherein:

[0006] The anode of the thyristor SCR1 is connected to the output positive electrode of the electric vehicle charger, the cathode of the thyristor SCR1 is connected to the positive electrode of the battery, and the output negative electrode of the electric vehicle charger is connected to the negative electrode of the battery and grounded;

[0007] The first rectifying and filtering unit is used to provide a conduction voltage for the thyristor SCR1 , and the thyristor driving control unit is used to control the conduction state of the thyristor SCR1 .

[0008] A further technical solution is that the first rectifier and filter unit includes a transformer, a diode D1 and an electrolytic capacitor EC2, wherein:

[0009] The anode of the diode D1 is connected to one end of the transformer secondary winding T1, the cathode of the diode D1 is connected to the positive electrode of the electrolytic capacitor EC2, and the negative electrode of the electrolytic capacitor EC2 is connected to the other end of the transformer secondary winding T1, the cathode of the thyristor SCR1 and the positive electrode of the battery.

[0010] Its further technical solution is that the thyristor drive control unit includes a resistor R2 and a photocoupler U204, wherein one end of the resistor R2 is connected to the positive electrode of the electrolytic capacitor EC2, and the other end of the resistor R2 is connected to the gate of the thyristor SCR1 through the secondary side phototransistor of the photocoupler U204.

[0011] A further technical solution is that the thyristor drive control unit also includes a resistor R3, one end of the resistor R3 is grounded through the primary light-emitting diode of the photocoupler U204, and the other end of the resistor R3 forms a BAT-ON connection end, and the BAT-ON connection end is connected to the MCU.

[0012] A further technical solution is that the BAT-ON connection end is connected to the I / O port of the MCU.

[0013] A further technical solution is that the thyristor drive control unit further includes a capacitor C2, one end of the capacitor C2 is connected to the cathode of the thyristor SCR1, and the other end of the capacitor C2 is connected to the gate of the thyristor SCR1.

[0014] A further technical solution is that it further includes a second rectifying and filtering unit, which includes a diode D2, an electrolytic capacitor EC1 and a resistor R1, wherein:

[0015] The output positive electrode of the electric vehicle charger is connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the positive electrode of the electrolytic capacitor EC1 and the anode of the thyristor SCR1;

[0016] The negative electrode of the electrolytic capacitor EC1 is connected to the output negative electrode of the electric vehicle charger and one end of the resistor R1 and is grounded, and the other end of the resistor R1 is connected to the negative electrode of the battery.

[0017] The beneficial technical effects of the utility model are:

[0018] The thyristor control circuit for an electric vehicle charger provided by this utility model places the thyristor in the charger's positive output line, cutting off the direct connection between the charger's positive output and the battery's positive terminal. This effectively reduces the power consumption of the thyristor trigger circuit and provides effective battery reverse polarity and backflow protection, ensuring the stability and safety of the entire charging process. Furthermore, the charger ground is always connected to the battery's negative terminal, ensuring no interference with the charger's mutual recognition and coordination with the battery before charging begins.

[0019] In addition, since the thyristor is isolated at the positive output of the charger, when the battery is disconnected, there will be no residual pressure at the charger output port even if the charger is powered on, further improving the safety and reliability of the charging process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The utility model provides a circuit principle diagram of an embodiment of a thyristor control circuit for an electric vehicle charger. DETAILED DESCRIPTION

[0021] In order to facilitate understanding of the present invention, the following will fully describe the specific embodiments of the present invention with reference to the relevant drawings. The drawings provide preferred embodiments of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0022] The utility model provides a thyristor control circuit for an electric vehicle charger, comprising an adaptively connected thyristor SCR1, a first rectifier and filter unit, and a thyristor drive control unit, wherein:

[0023] The anode of the thyristor SCR1 is connected to the positive output electrode of the electric vehicle charger, the cathode of the thyristor SCR1 is connected to the positive electrode of the battery, and the negative output electrode of the electric vehicle charger is connected to the negative electrode of the battery and grounded; the first rectifier and filter unit is used to provide a conduction voltage for the thyristor SCR1, and the thyristor drive control unit is used to control the conduction state of the thyristor SCR1.

[0024] Specifically, the thyristor SCR1 is connected between the positive output electrode of the electric vehicle charger and the positive electrode of the battery. When the thyristor SCR1 is not conducting, the connection between the positive output electrode of the electric vehicle charger and the positive electrode of the battery can be cut off, thereby realizing battery reverse connection protection and backflow protection. Compared with the traditional design of connecting the thyristor to the negative electrode of the electric vehicle charger, the thyristor control circuit provided by the present application does not need to add resistance between the positive and negative electrodes of the battery, which can effectively reduce the power consumption of the circuit. In addition, the electric vehicle charger ground and the negative electrode of the battery can always be connected, ensuring that the electric vehicle charger can recognize and cooperate with the battery before starting charging. In addition, since the thyristor is isolated between the positive output electrode of the electric vehicle charger and the positive electrode of the battery, when the battery is disconnected, even if the charger is in the power-on state, there will be no residual pressure at the charger output port, thereby ensuring the stability and safety of the entire charging process. The specific structural form of the first rectifier and filter unit and the thyristor drive control unit can refer to the following description, and the specific connection relationship of the thyristor SCR1, the first rectifier and filter unit and the thyristor drive control unit can also refer to the following description.

[0025] Figure 1 A circuit diagram of an embodiment of a thyristor control circuit is shown in FIG. Figure 1As shown, the first rectifier and filter unit includes a transformer, a diode D1 and an electrolytic capacitor EC2, wherein the anode of the diode D1 is connected to one end of the transformer secondary winding T1, the cathode of the diode D1 is connected to one end of the electrolytic capacitor EC2, and the other end of the electrolytic capacitor EC2 is connected to the other end of the transformer secondary winding T1, the cathode of the thyristor SCR1 and the positive electrode of the battery.

[0026] Specifically, the condition for a thyristor to conduct is that the voltage between the gate and cathode reaches the thyristor turn-on voltage. Since the cathode of thyristor SCR1 in this application is connected to the positive terminal of the battery, a floating voltage is required to drive the thyristor. Therefore, in the rectifier and filter circuit consisting of transformer secondary winding T1, diode D1, and electrolytic capacitor EC2, the negative terminal of electrolytic capacitor EC2 is connected to the cathode of thyristor SCR1 rather than to ground, thereby forming a floating voltage.

[0027] Furthermore, the thyristor drive control unit includes a resistor R2, a resistor R3, a capacitor C2, and a photocoupler U204. Resistors R2 and R3 are both current-limiting resistors. One end of resistor R2 is connected to the positive electrode of electrolytic capacitor EC2, and the other end of resistor R2 is connected to the gate of thyristor SCR1 via the secondary phototransistor of photocoupler U204. One end of resistor R3 is grounded via the primary light-emitting diode of photocoupler U204, and the other end of resistor R3 forms a BAT-ON connection terminal, which is connected to the MCU.

[0028] Specifically, the BAT-ON connection terminal is connected to the I / O port of the MCU, i.e., the data transmission interface. One end of the capacitor C2 is connected to the cathode of the thyristor SCR1, and the other end of the capacitor C2 is connected to the gate of the thyristor SCR1. The capacitor C2 has a filtering function to prevent the thyristor SCR1 from malfunctioning.

[0029] Resistor R3 and the primary-side LED of optocoupler U204 in the thyristor drive control unit form the pre-control stage of thyristor SCR1, which is controlled by the MCU. Resistor R2, capacitor C2, and the secondary-side phototransistor of optocoupler U204 form the drive circuit for thyristor SCR1. When the MCU I / O port outputs a high level, the BAT-ON connection terminal also goes high, turning on the primary-side LED of optocoupler U204 and the secondary-side phototransistor of optocoupler U204. At this time, the voltage on electrolytic capacitor EC2 is applied between the gate and cathode of thyristor SCR1 through current-limiting resistor R2 and the secondary-side phototransistor of optocoupler U204. When the voltage between the gate and cathode of thyristor SCR1 reaches the turn-on voltage of thyristor SCR1, thyristor SCR1 turns on, forming a charging path between the positive output terminal of the electric vehicle charger and the positive terminal of the battery.

[0030] The thyristor control circuit for the electric vehicle charger also includes a second rectifier and filter unit for forming a rectifier and filter circuit of the secondary side of the charger. The second rectifier and filter unit includes a diode D2, an electrolytic capacitor EC1, and a resistor R1. The output positive electrode of the electric vehicle charger is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the positive electrode of the electrolytic capacitor EC1 and the anode of the thyristor SCR1, the negative electrode of the electrolytic capacitor EC1 is connected to the output negative electrode of the electric vehicle charger and one end of the resistor R1 and is grounded, and the other end of the resistor R1 is connected to the negative electrode of the battery.

[0031] In summary, the thyristor control circuit for an electric vehicle charger provided by the present invention can reduce circuit power consumption, does not affect the mutual recognition and coordination between the electric vehicle charger and the battery before starting charging, and improves the safety and reliability of the entire charging process.

[0032] It should be noted that the terms "first" and "second" used in the above description are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0034] The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment. It is understood that other improvements and variations directly derived or imagined by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of protection of the present invention.

Claims

1. A thyristor control circuit for an electric vehicle charger, characterized in that: It includes an adaptively connected thyristor SCR1, a first rectifier and filter unit, and a thyristor drive control unit, wherein: The anode of the thyristor SCR1 is connected to the positive output electrode of the electric vehicle charger, the cathode of the thyristor SCR1 is connected to the positive electrode of the battery, and the negative output electrode of the electric vehicle charger is connected to the negative electrode of the battery and grounded; the first rectifier and filter unit is used to provide a conduction voltage for the thyristor SCR1, and the thyristor drive control unit is used to control the conduction state of the thyristor SCR1.

2. The thyristor control circuit for an electric vehicle charger according to claim 1, characterized in that: The first rectifier and filter unit includes a transformer, a diode D1 and an electrolytic capacitor EC2, wherein: The anode of the diode D1 is connected to one end of the transformer secondary winding T1, the cathode of the diode D1 is connected to the positive electrode of the electrolytic capacitor EC2, and the negative electrode of the electrolytic capacitor EC2 is connected to the other end of the transformer secondary winding T1, the cathode of the thyristor SCR1 and the positive electrode of the battery.

3. The thyristor control circuit for an electric vehicle charger according to claim 2, characterized in that: The thyristor drive control unit includes a resistor R2 and a photocoupler U204, wherein one end of the resistor R2 is connected to the positive electrode of the electrolytic capacitor EC2, and the other end of the resistor R2 is connected to the gate of the thyristor SCR1 through the secondary side phototransistor of the photocoupler U204.

4. The thyristor control circuit for an electric vehicle charger according to claim 3, characterized in that: The thyristor drive control unit further includes a resistor R3, one end of the resistor R3 is grounded via the primary light emitting diode of the photocoupler U204, and the other end of the resistor R3 forms a BAT-ON connection end, which is connected to the MCU.

5. The thyristor control circuit for an electric vehicle charger according to claim 4, characterized in that: The BAT-ON connection end is connected to the I / O port of the MCU.

6. The thyristor control circuit for an electric vehicle charger according to claim 3, characterized in that: The thyristor drive control unit further includes a capacitor C2 , one end of the capacitor C2 is connected to the cathode of the thyristor SCR1 , and the other end of the capacitor C2 is connected to the gate of the thyristor SCR1 .

7. The thyristor control circuit for an electric vehicle charger according to claim 1, characterized in that: It also includes a second rectifying and filtering unit, which includes a diode D2, an electrolytic capacitor EC1 and a resistor R1, wherein: The output positive electrode of the electric vehicle charger is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the positive electrode of the electrolytic capacitor EC1 and the anode of the thyristor SCR1, the negative electrode of the electrolytic capacitor EC1 is connected to the output negative electrode of the electric vehicle charger and one end of the resistor R1 and is grounded, and the other end of the resistor R1 is connected to the negative electrode of the battery.

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