Drive circuit for protector

Abstract

The utility model provides a drive circuit for a protector, and relates to the field of drive circuits, the drive circuit for the protector comprises a conversion circuit, a voltage stabilization and reduction circuit, a comparison circuit, a single-chip microcomputer and a choke circuit, when a load end does not consume power, a pre-charging resistor performs self-equalization so as to maintain the voltage difference to be less than 10%, and then the load end does not consume power. At the moment, the electric shock protector does not need to be started; according to the starting condition of the electric shock protector, when the load end has the power consumption condition and the pre-charging resistor cannot or loses the self-balancing function, the electric shock protector monitors low voltage (voltage difference) starting, and after the electric shock protector is started, the single-chip microcomputer calculates and distributes adaptive supplementary current magnitude at the moment according to the detected voltage difference between the high end and the low end; and the pressure difference is maintained to be less than 10% again, so that the risk of electric arc is avoided.

Description

Technical Field

[0001] The present application relates to the field of drive circuits, and in particular to a drive circuit for a protector. Background Art

[0002] New energy electric vehicles often face low voltage and high current structures. When the power is turned on, a large current flows from the high voltage end to the unloaded low voltage end, and a spark gap will be generated between the contacts of the circuit breaker (contactor). The temperature reached instantly is equivalent to the melting temperature of arc welding, which will cause the contacts of the circuit breaker to stick and the line cannot be closed, resulting in accidents. The industry is accustomed to using pre-charging resistors to use bypass discharge resistors to discharge a small amount of current to the low voltage end, so that the low voltage end gradually increases the voltage before connecting the circuit breaker. When there is a load on the low voltage end that has not been disconnected, the voltage has not increased to a safe connection voltage difference, and adhesion will still cause the fault to continue to occur. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a driving circuit for a protector, which can solve the above-mentioned technical problems.

[0004] An embodiment of the present application provides a driving circuit for a protector, including a conversion circuit, a voltage-stabilizing and step-down circuit, a comparison circuit, a single-chip microcomputer, and a choke circuit. The input end of the conversion circuit is externally connected to a power supply, the output end of the conversion circuit is connected to the input end of the voltage-stabilizing and step-down circuit, the output end of the voltage-stabilizing and step-down circuit is used to power the single-chip microcomputer, the output end of the comparison circuit and the output end of the choke circuit are both connected to the single-chip microcomputer, the input end of the comparison circuit is externally connected to a high-voltage monitoring input circuit, and the output end of the choke circuit is externally connected to an IGBT driver.

[0005] Preferably, the model of the single chip microcomputer is AT89C2051.

[0006] Preferably, the conversion circuit converts the +24V DC power of the external power supply into +12V DC power.

[0007] Preferably, the voltage stabilizing and step-down circuit includes a diode, a voltage regulator, and an inductor, the input end of the diode is connected to the conversion circuit, the output end of the diode is connected to the Vin end of the voltage regulator, the Vout end of the voltage regulator is connected to the single-chip microcomputer, and the GND end of the voltage regulator is grounded.

[0008] Preferably, the comparison circuit comprises a comparator and an adjustable resistor, and the model of the comparator is LM339.

[0009] Beneficial effects of the utility model:

[0010] The utility model provides a driving circuit for a protector, comprising a conversion circuit, a voltage-stabilizing and voltage-reducing circuit, a comparison circuit, a single-chip microcomputer, and a choke circuit. The input end of the conversion circuit is externally connected to a power supply, the output end of the conversion circuit is connected to the input end of the voltage-stabilizing and voltage-reducing circuit, the output end of the voltage-stabilizing and voltage-reducing circuit is used to power the single-chip microcomputer, the output end of the comparison circuit and the output end of the choke circuit are both connected to the single-chip microcomputer, the input end of the comparison circuit is externally connected to a high-voltage monitoring input circuit, the output end of the choke circuit is externally connected to an IGBT driver, and the utility model When there is no power consumption at the load end, the pre-charging resistor will perform self-balancing to maintain the voltage difference less than 10%, thereby preventing electric arc and there is no need to activate the electric shock protector at this time; Electric shock protector activation conditions: When there is power consumption at the load end and the pre-charging resistor cannot or loses the self-balancing function, the electric shock protector detects low voltage (voltage difference) and starts. After the electric shock protector is activated, the microcontroller will calculate and allocate the appropriate supplementary current based on the detected high and low end voltage difference, so that the voltage difference is maintained at less than 10%, thereby avoiding the risk of arc. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 This is a circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0014] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0015] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0016] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0017] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0018] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0019] like Figure 1As shown, a driving circuit for a protector includes a conversion circuit, a voltage-stabilizing and voltage-reducing circuit, a comparison circuit, a single-chip microcomputer, and a choke circuit. The input end of the conversion circuit is externally connected to a power supply, the output end of the conversion circuit is connected to the input end of the voltage-stabilizing and voltage-reducing circuit, the output end of the voltage-stabilizing and voltage-reducing circuit is used to power the single-chip microcomputer, the output end of the comparison circuit and the output end of the choke circuit are both connected to the single-chip microcomputer, the input end of the comparison circuit is externally connected to a high-voltage monitoring input circuit, and the output end of the choke circuit is externally connected to an IGBT driver. When the load When there is no power consumption at the load end, the pre-charge resistor will perform self-balancing to maintain the voltage difference less than 10%, thereby not causing an arc, and there is no need to start the electric shock protector; Electric shock protector startup conditions: When there is power consumption at the load end and the pre-charge resistor cannot or loses the self-balancing function, the electric shock protector detects the low voltage (voltage difference) and starts. After the electric shock protector is started, the microcontroller will calculate and distribute the appropriate supplementary current based on the detected high and low end voltage difference, so that the voltage difference is maintained at less than 10% again, thereby avoiding the risk of arcing.

[0020] Specifically, an IGBT tube is used to introduce high-voltage current, a choke circuit is used to effectively prevent large current surges, and a transistor is used to control the strength of the current to eliminate contact arcs. The high-voltage monitoring input line Connetor 1 is connected to the 18th pin of the AT89C2051 microcontroller, and the low-voltage comparison circuit is connected to the 17th pin of the microcontroller by Connector 2.

[0021] like Figure 1 As shown, in this embodiment, the model of the single chip microcomputer is AT89C2051.

[0022] like Figure 1 As shown, in this embodiment, the conversion circuit converts the +24V direct current of the external power supply into a +12V direct current. Specifically, the voltage conversion is performed through a DC / DC converter.

[0023] like Figure 1 As shown, in this embodiment, the voltage stabilizing and step-down circuit includes a diode, a voltage stabilizer, and an inductor. The input end of the diode is connected to the conversion circuit, the output end of the diode is connected to the Vin end of the voltage stabilizer, the Vout end of the voltage stabilizer is connected to the single-chip microcomputer, and the GND end of the voltage stabilizer is grounded. Specifically, the voltage stabilizing and step-down circuit reduces the DC +12V voltage to DC +5V.

[0024] like Figure 1 As shown, in this embodiment, the comparison circuit includes a comparator and an adjustable resistor. The model of the comparator is LM339. Specifically, the variable resistor on the comparison circuit adjusts the low-end voltage value of the comparator LM339 chip to maintain a 10% voltage difference.

[0025] The utility model overcomes the shortcomings of low power and low flow of pre-charging resistor and inability to increase low-end voltage; the shortcoming of large current rushing to the low-voltage end must be controlled to avoid arc effect; the voltage at the high-voltage end and the voltage at the low-voltage end are imported for monitoring, and the voltage difference at the two ends is less than 10% as the preset standard; when the voltage at the two ends reaches the standard, the circuit breaker is engaged.

[0026] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A driving circuit for a protector, characterized in that: It includes a conversion circuit, a voltage-stabilizing and step-down circuit, a comparison circuit, a single-chip microcomputer, and a choke circuit. The input end of the conversion circuit is externally connected to a power supply, the output end of the conversion circuit is connected to the input end of the voltage-stabilizing and step-down circuit, the output end of the voltage-stabilizing and step-down circuit is used to power the single-chip microcomputer, the output end of the comparison circuit and the output end of the choke circuit are both connected to the single-chip microcomputer, the input end of the comparison circuit is externally connected to a high-voltage monitoring input circuit, and the output end of the choke circuit is externally connected to an IGBT driver.

2. A driving circuit for a protector according to claim 1, characterized in that: The model of the single chip microcomputer is AT89C2051.

3. A driving circuit for a protector according to claim 1, characterized in that: The conversion circuit converts the +24V direct current of the external power supply into +12V direct current.

4. The driving circuit for a protector according to claim 1, characterized in that: The voltage stabilizing and step-down circuit includes a diode, a voltage stabilizer, and an inductor. The input end of the diode is connected to the conversion circuit, the output end of the diode is connected to the Vin end of the voltage stabilizer, the Vout end of the voltage stabilizer is connected to the single-chip microcomputer, and the GND end of the voltage stabilizer is grounded.

5. The driving circuit for a protector according to claim 1, characterized in that: The comparison circuit includes a comparator and an adjustable resistor, and the model of the comparator is LM339.

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