CN116666172A - Circuit breaker control method and circuit breaker system - Google Patents

Abstract

The application provides a circuit breaker control method and a circuit breaker system. The circuit breaker system includes: an electromagnetic switch unit, the electromagnetic switch unit is arranged on the power circuit, and is configured to control the power supply circuit to be turned on or off; a current sensor, the current sensor is coupled On the power supply circuit, the current sensor is configured to detect the operating current in the power supply circuit; the control unit, at least one end of the control unit is coupled to the current sensor, and at least one end is coupled to the electromagnetic switch unit, and the control unit is used to provide the electromagnetic switch according to the magnitude of the operating current. The switch unit outputs a control signal, and the control signal is used to control the closing current of the electromagnetic switch unit; wherein, when the operating current is greater than a first preset value, the closing current is smaller than the preset safety holding current of the electromagnetic switch unit. The application can speed up the release switch speed of the electromagnetic switch unit, and finally achieve the purpose of quickly turning off the electromagnetic switch unit and avoiding equipment damage.

Description

Circuit breaker control method and circuit breaker system

technical field

The present application relates to the technical field of electrical equipment, in particular to a circuit breaker control method and a circuit breaker system.

Background technique

A circuit breaker is a switching device that can close, carry and break current under normal circuit conditions. At present, the circuit breaker mainly controls the conduction or disconnection of the power circuit indirectly through the electromagnetic switch unit. For example, when the electromagnetic switch unit is powered on , the electromagnetic switch unit generates a magnetic pull-in switch to make the power circuit conduction; and when the electromagnetic switch unit is disconnected, the electromagnetic switch unit releases the switch to disconnect the power circuit.

However, the electromagnetic switch unit is a kind of inductive load. When a short-circuit current is generated in the power circuit, the freewheeling characteristics of the inductive load keep it in the working state for a period of time, so that the switch cannot be disconnected quickly. Failure (such as short-circuit current) can not be shut down quickly and cause equipment damage.

Contents of the invention

The present application provides a circuit breaker control method and a circuit breaker system, aiming at solving the technical problem that the current electromagnetic switch unit cannot be disconnected quickly.

In the first aspect, the present application provides a circuit breaker control method, the method is used to control the electromagnetic switch unit in the power circuit, the electromagnetic switch unit is configured to control the power circuit to be turned on or off, the method includes:

Detect the working current in the power circuit;

Output a control signal according to the size of the working current, and the control signal is used to control the closing current of the electromagnetic switch unit;

Wherein, when the working current is greater than the first preset value, the closing current is smaller than the preset safety holding current of the electromagnetic switch unit.

In some embodiments, when the working current is greater than the first preset value and smaller than the second preset value, the magnitude of the closed current and the magnitude of the working current change in opposite directions.

In some embodiments, when the working current is less than the first preset value, the closed current is equal to the preset safe holding current of the electromagnetic switch unit;

When the working current is equal to the second preset value, the closing current is equal to the preset minimum holding current of the electromagnetic switch unit.

In some embodiments, according to the magnitude of the working current, the step of controlling the magnitude of the closing current of the electromagnetic switch unit includes:

According to the size of the working current, determine the duty cycle of the pulse signal;

According to the duty ratio of the pulse signal, a control signal with a duty ratio of the pulse signal is output, and the control signal is used to control the connection or disconnection of the electromagnetic switch unit with the power supply.

In some embodiments, when the operating current is greater than the first preset value and smaller than the second preset value, the duty cycle of the pulse signal and the magnitude of the operating current change in opposite directions.

In some embodiments, when the operating current is greater than or equal to the second preset value, the power supply to the electromagnetic switch unit is stopped.

In a second aspect, the present application provides a circuit breaker system, including:

The electromagnetic switch unit is arranged on the power circuit and is configured to control the power circuit to be turned on or off;

a current sensor, the current sensor is coupled to the power loop, and the current sensor is configured to detect the operating current in the power loop;

A control unit, at least one end of the control unit is coupled to the current sensor, and at least one end is coupled to the electromagnetic switch unit, the control unit is used to output a control signal to the electromagnetic switch unit according to the magnitude of the operating current, and the control signal is used to control the closing current of the electromagnetic switch unit ;

Wherein, when the working current is greater than the first preset value, the closing current is smaller than the preset safety holding current of the electromagnetic switch unit.

In some embodiments, when the working current is greater than the first preset value and smaller than the second preset value, the magnitude of the closed current and the magnitude of the working current change in opposite directions.

In some embodiments, when the working current is less than the first preset value, the closing current is equal to the preset safe holding current of the electromagnetic switch unit.

In some embodiments, when the working current is equal to the second preset value, the closing current is equal to the preset minimum holding current of the electromagnetic switch unit.

In some embodiments, the control signal is a pulse signal;

When the operating current is greater than the first preset value and smaller than the second preset value, the duty cycle of the pulse signal and the magnitude of the operating current change in opposite directions.

In some embodiments, the circuit breaker system further includes a control switch unit, one end of the electromagnetic switch unit is coupled to the DC power supply end, and the other end is coupled to the ground end;

The control switch unit includes a first switch, one end of the first switch is connected to the electromagnetic switch unit, and the other end is connected to the DC power supply terminal or the ground terminal, and the control terminal of the first switch is coupled to the control unit, so that the pulse signal directly or indirectly controls the The switch state of the first switch.

In some embodiments, the circuit breaker system further includes a short circuit protection unit and a drive unit;

The input end of the short-circuit protection unit is connected to the current sensor, the output end of the short-circuit protection unit is connected to the first input end of the drive unit, the control unit is connected to the second input end of the drive unit, and the output end of the drive unit is connected to the control of the first switch terminal connection;

When the operating current is greater than the second preset value, the short circuit protection unit outputs a short circuit protection signal to turn off the first switch.

In some embodiments, the short circuit protection unit includes a first comparator, and the circuit breaker system further includes a current signal processing unit;

The input terminal of the current signal processing unit is connected to the current sensor, the output terminal of the current signal processing unit is connected to the non-inverting input terminal of the first comparator, and the current signal processing unit is used to convert the current signal of the current sensor into a voltage signal;

The inverting input terminal of the first comparator is connected to the first preset voltage, and the output terminal of the first comparator is coupled to the first input terminal of the driving unit, so that the first comparator compares the operating current with the second preset value size and outputs a short-circuit protected signal.

In some embodiments, the short circuit protection unit further includes a second comparator;

The non-inverting input terminal of the second comparator is connected to the second preset voltage, the inverting input terminal of the second comparator is coupled to the output terminal of the current signal processing unit, and the output terminal of the second comparator is coupled to the first drive unit. input.

In some embodiments, the short circuit protection unit further includes a first OR gate;

the output terminals of the first comparator and the second comparator are coupled to the first input terminal of the first OR gate;

The second input end of the first OR gate is coupled to its output end, and the output end of the first OR gate is connected to the first input end of the driving unit.

The present application detects the working current in the power circuit through the current sensor, and uses the control unit to output the control signal to control the closing current of the electromagnetic switch unit. When the working current is greater than the first preset value, the closing current of the electromagnetic switching unit is smaller than the electromagnetic switching unit. The preset safe holding current of the switch unit, that is, before the working current of the power circuit reaches the short-circuit current (or overload current), the closing current of the electromagnetic switch unit is reduced in advance, and the working current of the power supply reaches the short-circuit current (or overload current) Overload current) is large, because the closing current of the electromagnetic switch unit has been reduced in advance, so disconnecting the power supply of the electromagnetic switch unit can speed up the release switch speed of the electromagnetic switch unit, and finally achieve the phenomenon of quickly turning off the electromagnetic switch unit and avoiding equipment damage .

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is a schematic diagram of a module of a circuit breaker system provided in an embodiment of the present application;

FIG. 2 is a schematic flow chart of a circuit breaker control method provided in an embodiment of the present application;

Fig. 3 is a schematic flow chart of controlling the size of the closing current provided in the embodiment of the present application;

Fig. 4 is a schematic diagram of the change of the working current of the power circuit provided in the embodiment of the present application;

Fig. 5 is a schematic diagram of the variation of the closing current of the electromagnetic switch unit provided in the embodiment of the present application;

Fig. 6 is a schematic diagram of a circuit structure of the electromagnetic switch unit and the control switch unit provided in the embodiment of the present application;

FIG. 7 is a schematic diagram of a circuit structure of a short circuit protection unit provided in an embodiment of the present application;

FIG. 8 is a schematic diagram of a circuit structure of a driving unit provided in an embodiment of the present application.

Among them, 10 electromagnetic switch units, 20 current sensors, 30 control units, 40 control switch units, 50 short-circuit protection units, 60 drive units, 70 current signal processing units, and 80 communication units;

The first comparator U3, the second comparator U4, the first switch Q2, the first OR gate U2, and the gate driver U1.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The orientation or positional relationship indicated by "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation shown in the drawings Or positional relationship is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In this application, the word "exemplary" is used to mean "serving as an example, illustration or illustration". Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to make and use the invention. In the following description, details are set forth for purposes of explanation. It should be understood that one of ordinary skill in the art would recognize that the present invention may be practiced without the use of these specific details. In other instances, well-known structures and procedures are not described in detail to avoid obscuring the description of the present invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in this application.

Embodiments of the present application provide a circuit breaker control method and a circuit breaker system, which will be described in detail below.

First, referring to FIG. 1 and FIG. 2, FIG. 1 shows a block diagram of a circuit breaker system in the embodiment of the present application, and FIG. 2 shows a schematic flow chart of a circuit breaker control method in the embodiment of the present application, wherein, The circuit breaker control method is used to control the electromagnetic switch unit 10 in the power circuit. The electromagnetic switch unit 10 is configured to control the power circuit to be turned on or off. The circuit breaker control method includes:

Step S201, detecting the working current in the power circuit;

In some embodiments of the present application, the current sensor 20 can detect the working current in the power circuit, and transmit the signal to the control unit 30, so that the control unit 30 can judge whether the working current in the power circuit is greater than the overload current or the short circuit is broken. flow. In some embodiments of the present application, the output signal of the current sensor 20 may be a voltage signal, so that the comparator can be used to determine whether the power circuit is overloaded or short-circuited. In some embodiments of the present application, the output signal of the current sensor 20 may be a current signal.

Exemplarily, the current sensor 20 can measure current by adopting principles such as Hall, TMR (tunnel magnetoresistance), fluxgate or Rogowski coil; or, the current sensor 20 can also be realized by a shunt.

Step S202, outputting a control signal according to the size of the working current, the control signal is used to control the closing current of the electromagnetic switch unit; wherein, when the working current is greater than the first preset value, the closing current is smaller than the preset safety holding current of the electromagnetic switching unit .

It should be noted that, since the electromagnetic force of the electromagnetic switch unit 10 is related to the magnitude of the current, the electromagnetic switch unit 10 has a preset safe holding current and a preset minimum holding current, wherein the preset minimum holding current refers to the electromagnetic switch unit 10 The minimum closed current, the preset safe holding current is greater than the preset minimum holding current (for example greater than 2A), the preset safe holding current refers to the current of the electromagnetic switch unit 10 in a normal working state. When the magnitude of the current passed through the electromagnetic switch unit 10 is equal to the preset safe holding current, the magnetic force generated by the electromagnetic switch unit 10 will be greater than the elastic force (for example, greater than 10N) of the corresponding elastic member (such as a spring), thereby ensuring that the electromagnetic switch unit 10 is stable. closed state of the closed state; when the electric current of the electromagnetic switch unit 10 is equal to the preset minimum holding current, the magnetic force generated by the electromagnetic switch unit 10 is basically equivalent to the elastic force of the corresponding elastic member (such as a spring). If the current of the electromagnetic switch unit 10 is further If it is lowered, the electromagnetic switch unit 10 will be turned off. Normally, in order to avoid the stability of the electromagnetic switch unit 10, the electromagnetic switch unit 10 is usually fed with a preset safe holding current to work, so as to prevent the electromagnetic switch unit 10 from feeding the preset minimum holding current and causing the electromagnetic switch The frequent closing and opening of the unit 10.

In some embodiments of the present application, the control signal is a pulse signal, and the duty cycle of the pulse signal determines its average voltage/current. The larger the duty cycle, the larger the average voltage/current of the pulse signal. The smaller the ratio, the smaller the average voltage/current of the pulse signal. In some embodiments of the present application, when the pulse signal supplies power to the electromagnetic switch unit 10, the greater the duty ratio, the greater the closing current of the electromagnetic switch unit 10, and vice versa, the smaller the current, so the control unit 30 changes The duty ratio of the output control signal can realize the purpose of changing the closing current of the electromagnetic switch unit 10 .

It can be understood that the control signal can also be a voltage signal, and the output current of the voltage-controlled current source is controlled by the voltage signal, thereby controlling the closing current of the electromagnetic switch unit 10 .

After obtaining the size of the working current, when the working current is greater than the first preset value, the closed current can be controlled to be less than the preset safe holding current of the electromagnetic switch unit, that is, the working current in the power circuit reaches the short-circuit current (or Before the size of the overload current), the closing current of the electromagnetic switch unit 10 is reduced in advance. When the operating current of the power supply reaches the size of the short-circuit current (or overload current), since the closing current of the electromagnetic switch unit 10 has been reduced in advance, the electromagnetic switch is disconnected. The power supply of the unit 10 can accelerate the release speed of the electromagnetic switch unit 10, and finally achieve the phenomenon of rapidly turning off the electromagnetic switch unit 10 and avoiding equipment damage.

Step S203, when the operating current is greater than or equal to the second preset value, stop supplying power to the electromagnetic switch unit 10 .

In some embodiments of the present application, the first preset value may be equal to the overload current of the current loop (eg, 5A), and the second preset value may be equal to the short-circuit current of the power loop (eg, 10A). In some embodiments of the present application, the first preset value may be equal to the rated current of the current loop (eg 3A), and the second preset value may be equal to the overload current of the power loop (eg 5A).

Taking the first preset value as the overload current of the current loop and the second preset value as the short-circuit current of the current loop as an example, when an overload current occurs in the power supply loop, the control unit 30 can reduce the closing current of the electromagnetic switch unit 10, and When a short-circuit current occurs in the power circuit, the power supply to the electromagnetic switch unit 10 is stopped, and the electromagnetic switch unit 10 with a smaller closing current generates a smaller self-inductance current, so after the electromagnetic switch unit 10 is powered, the short-circuit phenomenon in the power circuit can be accelerated The opening speed of the rear electromagnetic switch unit 10.

In some embodiments of the present application, referring to FIG. 3, FIG. 3 shows a schematic flow chart of controlling the magnitude of the closed current in the embodiment of the present application, wherein controlling the magnitude of the closed current includes:

Step S301, determining the pulse signal duty cycle according to the magnitude of the operating current;

Step S302, outputting a control signal with a duty ratio of the pulse signal according to the duty ratio of the pulse signal, and the control signal is used to control the connection or disconnection of the electromagnetic switch unit with the power supply.

It should be noted that the duty cycle of the pulse signal determines its average voltage/current. The larger the duty cycle, the larger the average voltage/current of the pulse signal, and the smaller the duty cycle, the greater the average voltage/current of the pulse signal. The smaller the magnitude of the current. When the control signal controls the switch of the electromagnetic switch unit 10 connected to the power supply, the larger the duty ratio, the longer the average time for the connection of the electromagnetic switch unit 10 to the power supply, so the closing current is larger, otherwise the closing current is smaller , so the purpose of changing the magnitude of the closing current of the electromagnetic switch unit 10 can be achieved by changing the duty ratio of the output control signal of the control unit 30 .

Exemplarily, the pulse signal can be a PWM signal or a clock signal. For example, when the control unit 30 is a single-chip microcomputer, the PWM signal is output through the PWM port of the single-chip microcomputer; The triangular wave or sawtooth wave generator produces high-frequency modulation wave, and then generates PWM signal through comparator. In some embodiments, when the operating current is greater than the first preset value and smaller than the second preset value, the duty cycle of the pulse signal and the size of the operating current change in the opposite direction; for example, when the operating current changes from the first preset value When gradually increasing to the second preset value, the duty cycle of the pulse signal gradually decreases, so that the closing current of the electromagnetic switch unit 10 decreases accordingly; on the contrary, when the operating current gradually decreases from the second preset value to the first When the preset value is reached, the duty cycle of the pulse signal increases gradually, so that the closing current of the electromagnetic switch unit 10 increases accordingly.

Understandably, the control unit 30 can also change the power supply voltage of the electromagnetic switch unit 10 to reduce the closing current of the electromagnetic switch unit 10 .

In some embodiments of the present application, continue to refer to Fig. 4 and Fig. 5, Fig. 4 shows a schematic diagram of the working current change of the power circuit in the embodiment of the present application, and Fig. 5 shows the electromagnetic switch in the embodiment of the present application A schematic diagram of the change of the closing current of the unit 10, wherein, when the operating current is greater than the first preset value and smaller than the second preset value, the magnitude of the closing current and the magnitude of the operating current change in opposite directions.

It should be noted that there are three types of current in the current loop: rated current, overload current and short-circuit current. The rated current refers to the normal operating current of the current loop, and the overload current refers to the working current of the power supply loop that is greater than the rated current and less than the short-circuit current. Current, short circuit current refers to the working current when a short circuit occurs in the power circuit.

In the above embodiment, since when the working current is greater than the first preset value and smaller than the second preset value, the magnitude of the closed current and the magnitude of the working current change in the opposite direction, that is, as the working current in the current loop From the first preset value (such as overload current) to the second preset value (short-circuit current), the closing current of the electromagnetic switch unit 10 gradually decreases. After the operating current is close to or equal to the overload current or short-circuit current, At this time, disconnecting the power supply of the electromagnetic switch unit 10 can accelerate the release switch of the electromagnetic switch unit 10, and then cut off the current quickly when an overload current or a short-circuit current occurs; For example, the short-circuit current) gradually decreases to the first preset value (overload current), then the closing current of the electromagnetic switch unit 10 gradually increases to ensure the electromagnetic force of the electromagnetic switch unit 10 when no overload or short circuit occurs.

Further, in some embodiments of the present application, continue to refer to FIG. 4 and FIG. 5 , wherein, when the operating current is less than the first preset value (such as rated current or overload current), the magnitude of the closing current is equal to that of the electromagnetic switch unit 10 The preset safe holding current is beneficial to keep the electromagnetic switch unit in a stable working state when the working current of the power circuit is normal.

Further, in some embodiments of the present application, continue to refer to FIG. 4 and FIG. 5 , when the operating current is equal to the second preset value (such as overload current or short-circuit current), the magnitude of the closing current is equal to the preset value of the electromagnetic switch unit 10. If the minimum holding current is set, and the power supply of the electromagnetic switch unit 10 is disconnected at this time, the electromagnetic switch unit 10 can be quickly disconnected when the power circuit is overloaded or short-circuited.

Further, in order to better implement the circuit breaker control method in the embodiment of the present application, the present application also provides a circuit breaker system, continue to refer to Figure 1, wherein the circuit breaker system includes:

The electromagnetic switch unit 10, the electromagnetic switch unit 10 is arranged on the power circuit, and is configured to control the power circuit to be turned on or off;

A current sensor 20, the current sensor 20 is coupled to the power loop, and the current sensor 20 is configured to detect the operating current in the power loop;

Control unit 30, at least one end of the control unit 30 is coupled to the current sensor 20, and at least one end is coupled to the electromagnetic switch unit 10, the control unit 30 is used to output a control signal to the electromagnetic switch unit 10 according to the magnitude of the operating current, and the control signal is used to control the electromagnetic switch unit 10. The magnitude of the closing current of the switch unit 10;

Wherein, when the working current is greater than the first preset value, the closing current is smaller than the preset safe holding current of the electromagnetic switch unit 10 .

Specifically, the electromagnetic switch unit 10 refers to a switch unit that indirectly controls a switch to be closed through an electromagnetic effect. Generally, the electromagnetic switch unit 10 includes an electromagnetic part and a switch part, and the switch part has an elastic member (such as a spring or rubber) to maintain a normally open state or a normally closed state. Take the switch part to keep the normally open state as an example, when the electromagnetic switch unit 10 is energized, the electromagnetic part generates a magnetic pull-in switch to make the electromagnetic switch unit 10 close; on the contrary, when the electromagnetic switch unit 10 is powered off, the magnetic force of the electromagnetic part disappears to release the switch , the elastic force of the elastic member pulls the switch off so that the electromagnetic switch unit 10 is turned off. Exemplarily, the electromagnetic switch unit 10 may be a device having an electromagnetic switch function such as a relay or a contactor.

It can be understood that the switch part can also be in a normally closed state, and the electromagnetic part generates a magnetic force repelling the switch part, so that the switch part is turned off.

It should be noted that, since the magnitude of the electromagnetic force is related to the magnitude of the current, the electromagnetic switch unit 10 has a preset safe holding current and a preset minimum holding current, wherein the preset minimum holding current refers to the minimum current at which the electromagnetic switch unit 10 is closed , the preset safe holding current is greater than the preset minimum holding current (for example greater than 2A), and the preset safe holding current refers to the current of the electromagnetic switch unit 10 in a normal working state. When the magnitude of the current passed through the electromagnetic switch unit 10 is equal to the preset safe holding current, the magnetic force generated by the electromagnetic switch unit 10 will be greater than the elastic force (for example, greater than 10N) of the corresponding elastic member (such as a spring), thereby ensuring that the electromagnetic switch unit 10 is stable. closed state of the closed state; when the electric current of the electromagnetic switch unit 10 is equal to the preset minimum holding current, the magnetic force generated by the electromagnetic switch unit 10 is basically equivalent to the elastic force of the corresponding elastic member (such as a spring). If the current of the electromagnetic switch unit 10 is further If it is lowered, the electromagnetic switch unit 10 will be turned off. Normally, in order to avoid the stability of the electromagnetic switch unit 10, the electromagnetic switch unit 10 is usually fed with a preset safe holding current to work, so as to prevent the electromagnetic switch unit 10 from feeding the preset minimum holding current and causing the electromagnetic switch The frequent closing and opening of the unit 10.

The current sensor 20 is used to detect the operating current in the power circuit, so as to judge whether the operating current in the power circuit is greater than the overload current or short-circuited. In some embodiments of the present application, the output signal of the current sensor 20 may be a voltage signal, so that the comparator can be used to determine whether the power circuit is overloaded or short-circuited. In some embodiments of the present application, the output signal of the current sensor 20 may be a current signal.

Exemplarily, the current sensor 20 can measure current by adopting principles such as Hall, TMR (tunnel magnetoresistance), fluxgate or Rogowski coil; or, the current sensor 20 can also be realized by a shunt.

The control unit 30 is used to output a control signal and control the closing current magnitude control unit 30 of the electromagnetic switch unit 10 . In some embodiments of the present application, the control unit 30 can be realized by a micro-control chip (single-chip microcomputer). Various models, such as ST's STM32F103 series single-chip microcomputer, and the control program is well known to those skilled in the art, which can be obtained by those skilled in the art without creative labor. In some embodiments of the present application, the control unit 30 may include a comparator, and use the comparator to compare the voltage signal output by the current sensor 20 with a preset voltage signal, so as to determine whether the operating current is greater than the first preset value.

In the embodiment of the present application, the present application uses the current sensor 20 to detect the operating current in the power circuit, and uses the control unit 30 to output a control signal to control the closing current of the electromagnetic switch unit 10. When the operating current is greater than the first preset value , so that the closing current of the electromagnetic switch unit 10 is less than the preset safety holding current of the electromagnetic switch unit 10, that is, before the operating current of the power circuit reaches the short-circuit current (or overload current), the current of the electromagnetic switch unit 10 is reduced in advance. Closing current, when the operating current of the power supply reaches the short-circuit current (or overload current) size, because the closing current of the electromagnetic switch unit 10 has been reduced in advance, so disconnecting the power supply of the electromagnetic switch unit 10 can accelerate the release of the switch of the electromagnetic switch unit 10. speed, and finally achieve the phenomenon of rapidly turning off the electromagnetic switch unit 10 and avoiding equipment damage.

In some embodiments of the present application, continue to refer to FIG. 4 and FIG. 5 , wherein, when the operating current is greater than the first preset value and smaller than the second preset value, the magnitude of the closing current and the magnitude of the operating current change in opposite directions .

It should be noted that there are three types of current in the current loop: rated current, overload current and short-circuit current. The rated current refers to the normal operating current of the current loop, and the overload current refers to the working current of the power supply loop that is greater than the rated current and less than the short-circuit current. Current, short circuit current refers to the working current when a short circuit occurs in the power circuit. In some embodiments of the present application, the first preset value may be equal to the overload current of the current loop (eg, 5A), and the second preset value may be equal to the short-circuit current of the power loop (eg, 10A). In some embodiments of the present application, the first preset value may be equal to the rated current of the current loop (eg 3A), and the second preset value may be equal to the overload current of the power loop (eg 5A).

In the above embodiment, when the operating current is greater than the first preset value and smaller than the second preset value, the magnitude of the closed current and the magnitude of the operating current change in the opposite direction, that is, as the operating current in the current loop From the first preset value (such as overload current) to the second preset value (short-circuit current), the closing current of the electromagnetic switch unit 10 gradually decreases. After the operating current is close to or equal to the overload current or short-circuit current, At this time, disconnecting the power supply of the electromagnetic switch unit 10 can accelerate the release switch of the electromagnetic switch unit 10, and then cut off the current quickly when an overload current or a short-circuit current occurs; For example, the short-circuit current) gradually decreases to the first preset value (overload current), then the closing current of the electromagnetic switch unit 10 gradually increases to ensure the electromagnetic force of the electromagnetic switch unit 10 when no overload or short circuit occurs.

Further, in some embodiments of the present application, continue to refer to FIG. 4 and FIG. 5 , wherein, when the operating current is less than the first preset value (such as rated current or overload current), the magnitude of the closing current is equal to that of the electromagnetic switch unit 10 The preset safe holding current is beneficial to keep the electromagnetic switch unit in a stable working state when the working current of the power circuit is normal.

Further, in some embodiments of the present application, continue to refer to FIG. 4 and FIG. 5 , when the operating current is equal to the second preset value (such as overload current or short-circuit current), the magnitude of the closing current is equal to the preset value of the electromagnetic switch unit 10. If the minimum holding current is set, and the power supply of the electromagnetic switch unit 10 is disconnected at this time, the electromagnetic switch unit 10 can be quickly disconnected when the power circuit is overloaded or short-circuited.

In some embodiments of the present application, the control signal is a pulse signal, and when the working current is greater than the first preset value and smaller than the second preset value, the duty cycle of the pulse signal and the magnitude of the working current change in opposite directions.

It should be noted that the duty cycle of the pulse signal determines its average voltage/current. The larger the duty cycle, the larger the average voltage/current of the pulse signal, and the smaller the duty cycle, the greater the average voltage/current of the pulse signal. The smaller the magnitude of the current. In some embodiments of the present application, when the pulse signal supplies power to the electromagnetic switch unit 10, the greater the duty ratio, the greater the closing current of the electromagnetic switch unit 10, and vice versa, the smaller the current, so the control unit 30 changes The duty ratio of the output control signal can realize the purpose of changing the closing current of the electromagnetic switch unit 10 .

Exemplarily, the pulse signal can be a PWM signal or a clock signal. For example, when the control unit 30 is a single-chip microcomputer, the PWM signal is output through the PWM port of the single-chip microcomputer; The triangular wave or sawtooth wave generator produces high-frequency modulation wave, and then generates PWM signal through comparator.

In some embodiments of the present application, continue to refer to FIG. 6, which shows a schematic diagram of a circuit structure of the electromagnetic switch unit 10 and the control switch unit 40 in the embodiment of the present application, wherein the circuit breaker system also includes a control switch unit 40, one end of the electromagnetic switch unit 10 is coupled to the DC power supply terminal, and the other end is coupled to the ground terminal; the control switch unit 40 includes a first switch Q2, one end of the first switch Q2 is connected to the electromagnetic switch unit 10, and the other end is connected to the DC power supply The control terminal of the first switch Q2 is coupled to the control unit 30, so that the pulse signal directly or indirectly controls the switching state of the first switch Q2.

It should be noted that since the control signal is a pulse signal, the control signal can directly or indirectly control the first switch Q2 to be turned on or off alternately, for example, when the pulse signal is at a high level, the first switch Q2 is turned on, and when the pulse signal is When the level is low, the first switch Q2 is closed, and at the same time, since the electromagnetic switch unit 10 is connected to the DC power supply, the duty cycle of the pulse signal can control the closing time of the first switch Q2, that is, the time for the electromagnetic switch unit 10 to connect to the DC power supply , finally achieving the purpose of changing the magnitude of the current of the electromagnetic switch unit 10 .

Exemplarily, the first switch Q2 may be a transistor having a switching function such as a MOS transistor, an IGBT transistor, or a triode.

It can be understood that the control switch unit 40 may also include a first switch Q2 and a second switch Q1, the first switch Q2 and the second switch Q1 are respectively connected to the DC power supply terminal and the ground terminal, so that the power supply terminal and the ground terminal of the electromagnetic switch unit 10 are connected simultaneously. on or off.

In some embodiments of the present application, continue to refer to FIG. 6, FIG. 7 and FIG. 8, FIG. 7 shows a schematic circuit structure diagram of the short circuit protection unit 50 in the embodiment of the present application, and FIG. 8 shows a schematic diagram of the circuit structure of the embodiment of the present application A schematic diagram of a circuit structure of the drive unit 60, wherein the circuit breaker system also includes a short-circuit protection unit 50 and a drive unit 60; the input end of the short-circuit protection unit 50 is connected to the current sensor 20, and the output end of the short-circuit protection unit 50 is connected to the drive unit 60 is connected to the first input end, the control unit 30 is connected to the second input end of the drive unit 60, and the output end of the drive unit 60 is connected to the control end of the first switch Q2; when the operating current is greater than the second preset value, short circuit The protection unit 50 outputs a short circuit protection signal to turn off the first switch Q2.

It should be noted that the short-circuit protection unit 50 is used to determine whether the operating current is greater than a second preset value (for example, the short-circuit current 10A), so as to output a signal and turn off the first switch Q2 of the control switch unit 40 . In some embodiments of the present application, the short circuit protection unit 50 may include a comparator to compare the output voltage of the current sensor 20 (or the converted voltage signal of the output current signal) with a preset voltage value, so as to determine whether the There is an overload or short circuit phenomenon. The driving unit 60 may include a gate driver U1, the IN+ terminal of the gate driver U1 is connected to the PWM signal of the control unit 30, and the IN- terminal of the gate driver U1 is connected to the output signal of the short circuit protection unit 50 (such as the first or The output signal of the gate U2), and the output terminal out of the gate driver U1 can output a signal for controlling the opening or closing of the first switch Q2. That is to say, by setting the gate driver U1, on the one hand, the control unit 30 can be used to control the first switch Q2 through the gate driver U1; The pole driver U1 controls the first switch Q2 to ensure timely realization of the short circuit protection of the circuit breaker system.

It can be understood that the drive unit 60 can also use an OR gate, that is, the two input terminals of the OR gate are respectively connected to the signals of the short-circuit protection unit 50 and the control unit 30, and when the short-circuit protection unit 50 and the control unit 30 output a high level signal, the OR gate outputs a high-level signal and can change the switching state of the first switch Q2 , so that the short circuit protection unit 50 and the control unit 30 indirectly control the first switch Q2 through the driving unit 60 .

In some embodiments of the present application, for example, for the embodiment in which the current sensor 20 outputs a current signal, continue to refer to FIG. 7 , wherein the short circuit protection unit 50 includes a first comparator U3, and the circuit breaker system further includes a current signal processing unit 70; The input terminal of the current signal processing unit 70 is connected to the current sensor 20, the output terminal of the current signal processing unit 70 is connected to the non-inverting input terminal of the first comparator U3, and the current signal processing unit 70 is used to convert the current signal of the current sensor 20 into Voltage signal; the inverting input terminal of the first comparator U3 is connected to the first preset voltage, and the output terminal of the first comparator U3 is coupled to the first input terminal of the drive unit 60, so that the first comparator U3 compares the operating current and the second preset value and output a short-circuit protection signal.

It should be noted that since the current signal processing unit 70 converts the current signal of the current sensor 20 into a voltage signal, it can directly use the first comparator U3 to compare the voltage signal with the first preset voltage. When the current signal processing unit 70 outputs a voltage When the level value of the signal is greater than the level value of the first preset voltage, it indicates that the size of the operating current in the power circuit is greater than the second preset value (such as short-circuit current), so the first comparator U3 can output a high-level signal And the gate driver U1 controls the first switch Q2 to be turned off, so as to realize short-circuit protection or overload protection.

It can be understood that the short circuit protection unit 50 can also use a current comparator to directly compare the current signal output by the current sensor 20 to determine whether there is an overload current or a short circuit current in the power circuit. Further, in some embodiments of the present application, continue to refer to FIG. 7 , wherein the short circuit protection unit 50 further includes a second comparator U4; the non-inverting input terminal of the second comparator U4 is connected to a second preset voltage, and the second The inverting input terminal of the comparator U4 is coupled to the output terminal of the current signal processing unit 70 , and the output terminal of the second comparator U4 is coupled to the first input terminal of the driving unit 60 .

It should be noted that there are two directions of the short-circuit current in the power circuit, and in the above-mentioned embodiment, by setting the first comparator U3 and the second comparator U4 at the same time, the two comparators can simultaneously detect faults in two directions. For current judgment, as long as one of the first comparator U3 and the second comparator U4 outputs a high-level signal, the first switch Q2 can be turned off, so as to finally ensure the accuracy of the fault current judgment of the short circuit protection unit 50 .

In some embodiments of the present application, continue to refer to FIG. 7 , wherein the short circuit protection unit 50 further includes a first OR gate U2; the output terminals of the first comparator U3 and the second comparator U4 are coupled to the first OR gate U2 The first input end of the first OR gate U2 is coupled to its output end, and the output end of the first OR gate U2 is connected to the first input end of the driving unit 60 .

It should be noted that the short-circuit fault may occur in an instant and then be eliminated, so the short-circuit current may suddenly increase in an instant, and then decrease significantly after the relay is disconnected. In the above embodiment, after the output terminals of the first comparator U3 and the second comparator U4 output high-level signals, the first input terminal of the first OR gate U2 receives a high-level signal, and then the first OR The output terminal of the gate U2 outputs a high level signal, and since the second input terminal of the first OR gate U2 is coupled to the output terminal of the first OR gate U2, the second output terminal of the first OR gate U2 also receives a high level signal. level signal, so that the first OR gate U2 is in a self-locking state, and the output terminal of the first OR gate U2 continues to output a high level signal and is not affected by the subsequent output signals of the output terminals of the first comparator U3 and the second comparator U4 , to avoid the phenomenon that the short circuit cannot be effectively detected and judged when the short circuit current rises instantaneously and drops rapidly.

It can be understood that when the first input terminal and the second input terminal of the first OR gate U2 simultaneously receive a low-level signal (such as a low-level signal sent by the control unit 30 through the interface), the first OR gate U2 can be released. self-locking state.

It is worth noting that the above content about the circuit breaker system is intended to clearly illustrate the implementation and verification process of the application. Those skilled in the art can also make equivalent modified designs under the guidance of this application. For example, the circuit breaker system can also include Other functional modules, for example, referring to Figure 6, the circuit breaker system can also include a communication unit 80 to send circuit breaker operating data, such as short-circuit record data, overload record data, leakage record data, etc.; and for example, some circuits can also set the voltage Resistors and Zener diodes for conversion, as shown in Figure 6, resistors R1, R2, Zener diodes D1, D2, D3 and ZD1, capacitor C1, etc. can also be set in the control switch unit 40, or as shown in Figure 7, Resistors R5 , R6 , R7 , R8 , R9 , R10 , Zener diodes D4 , D5 , capacitors C4 , C5 , C6 , etc. can also be set in the short circuit protection unit 50 .

In the above-mentioned embodiments, the descriptions of each embodiment have their own emphases. For the part that is not described in detail in a certain embodiment, refer to the detailed description of other embodiments above, and will not be repeated here.

The basic concept has been described above, obviously, for those skilled in the art, the above detailed disclosure is only an example, and does not constitute a limitation to the present application. Although not expressly stated here, various modifications, improvements and amendments to this application may be made by those skilled in the art. Such modifications, improvements, and amendments are suggested in this application, so such modifications, improvements, and amendments still belong to the spirit and scope of the exemplary embodiments of this application.

Meanwhile, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and/or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that two or more references to "an embodiment" or "an embodiment" or "an alternative embodiment" in different places in this specification do not necessarily refer to the same embodiment . In addition, certain features, structures or characteristics of one or more embodiments of the present application may be properly combined.

In the same way, it should be noted that in order to simplify the expression disclosed in the present application and help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, sometimes multiple features are combined into one embodiment, drawings or descriptions thereof. This method of disclosure does not, however, imply that the subject matter of the application requires more features than are recited in the claims. Indeed, embodiment features are less than all features of a single foregoing disclosed embodiment.

In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of the embodiments use the modifiers "about", "approximately" or "substantially" in some examples. grooming. Unless otherwise stated, "about", "approximately" or "substantially" indicates that the stated figure allows for a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that can vary depending upon the desired characteristics of individual embodiments. In some embodiments, numerical parameters should take into account the specified significant digits and adopt the general digit reservation method. Although the numerical ranges and parameters used in some embodiments of the present application to confirm the breadth of the scope are approximate values, in specific embodiments, such numerical values are set as precisely as practicable.

Each patent, patent application, patent application publication, and other material, such as article, book, specification, publication, document, etc., cited in this application is hereby incorporated by reference into this application in its entirety, except for the contents of this application Inconsistent or conflicting application history documents are excluded, as are documents (currently or hereafter appended to this application) that limit the broadest scope of the claims of this application. It should be noted that if there is any inconsistency or conflict between the descriptions, definitions, and/or terms used in the attached materials of this application and the contents of this application, the descriptions, definitions and/or terms used in this application shall prevail .

A circuit breaker control method and a circuit breaker system provided by the embodiment of the present application have been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiment is only for helping Understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be construed as a limitation of the invention.

Claims (15)

1. A circuit breaker control method, characterized in that, the method is used to control an electromagnetic switch unit in a power supply circuit, and the electromagnetic switch unit is configured to control the conduction or disconnection of the power supply circuit, and the method includes : detecting the working current in the power circuit; Outputting a control signal according to the magnitude of the working current, the control signal is used to control the magnitude of the closing current of the electromagnetic switch unit; Wherein, when the operating current is greater than a first preset value, the closing current is smaller than a preset safety holding current of the electromagnetic switch unit. 2. The circuit breaker control method according to claim 1, wherein when the operating current is greater than a first preset value and smaller than a second preset value, the magnitude of the closing current is different from that of the operating current The size changes in the opposite direction. 3. The circuit breaker control method according to claim 1, wherein when the operating current is less than a first preset value, the magnitude of the closing current is equal to the preset safety holding current of the electromagnetic switch unit; When the working current is equal to the second preset value, the magnitude of the closing current is equal to a preset minimum holding current of the electromagnetic switch unit. 4. The circuit breaker control method according to claim 1, wherein the step of controlling the magnitude of the closing current of the electromagnetic switch unit according to the magnitude of the operating current comprises: Determine the pulse signal duty cycle according to the size of the working current; According to the duty ratio of the pulse signal, a control signal with the duty ratio of the pulse signal is output, and the control signal is used to control the connection or disconnection of the electromagnetic switch unit with the power supply. 5. The circuit breaker control method according to claim 4, characterized in that, when the operating current is greater than a first preset value and smaller than a second preset value, the pulse signal duty ratio and the operating current changes in size in the opposite direction. 6. The circuit breaker control method according to any one of claims 1 to 5, characterized in that the method further comprises: When the operating current is greater than or equal to a second preset value, the power supply to the electromagnetic switch unit is stopped. 7. A circuit breaker system, characterized in that it comprises: An electromagnetic switch unit, the electromagnetic switch unit is arranged on the power circuit and is configured to control the power circuit to be turned on or off; a current sensor, the current sensor is coupled to the power loop, and the current sensor is configured to detect the operating current in the power loop; a control unit, at least one end of the control unit is coupled to the current sensor, and at least one end is coupled to the electromagnetic switch unit, the control unit is configured to output a control signal to the electromagnetic switch unit according to the magnitude of the operating current, The control signal is used to control the closing current of the electromagnetic switch unit; Wherein, when the operating current is greater than a first preset value, the closing current is smaller than a preset safety holding current of the electromagnetic switch unit. 8. The circuit breaker system according to claim 7, wherein when the operating current is greater than a first preset value and smaller than a second preset value, the magnitude of the closing current and the magnitude of the operating current Change in the opposite direction. 9. The circuit breaker system according to claim 8, wherein when the operating current is less than a first preset value, the magnitude of the closing current is equal to the preset safety holding current of the electromagnetic switch unit; When the working current is equal to the second preset value, the magnitude of the closing current is equal to a preset minimum holding current of the electromagnetic switch unit. 10. The circuit breaker system according to any one of claims 7 to 9, wherein the control signal is a pulse signal; When the working current is greater than the first preset value and smaller than the second preset value, the duty cycle of the pulse signal changes in an opposite direction to the magnitude of the working current. 11. The circuit breaker system according to claim 10, wherein the circuit breaker system further comprises a control switch unit, one end of the electromagnetic switch unit is coupled to the DC power supply terminal, and the other end is coupled to the ground terminal; The control switch unit includes a first switch, one end of the first switch is connected to the electromagnetic switch unit, and the other end is connected to a DC power supply terminal or a ground terminal, and the control terminal of the first switch is coupled to the control unit , so that the pulse signal directly or indirectly controls the switching state of the first switch. 12. The circuit breaker system according to claim 11, further comprising a short circuit protection unit and a drive unit; The input end of the short-circuit protection unit is connected to the current sensor, the output end of the short-circuit protection unit is connected to the first input end of the drive unit, and the control unit is connected to the second input end of the drive unit , the output end of the drive unit is connected to the control end of the first switch; When the operating current is greater than a second preset value, the short circuit protection unit outputs a short circuit protection signal to turn off the first switch. 13. The circuit breaker system according to claim 12, wherein the short circuit protection unit comprises a first comparator, and the circuit breaker system further comprises a current signal processing unit; The input terminal of the current signal processing unit is connected to the current sensor, the output terminal of the current signal processing unit is connected to the non-inverting input terminal of the first comparator, and the current signal processing unit is used to convert the current The current signal of the sensor is converted into a voltage signal; The inverting input terminal of the first comparator is connected to a first preset voltage, and the output terminal of the first comparator is coupled to the first input terminal of the driving unit, so that the first comparator compares the The size of the working current and the second preset value and output the short circuit protection signal. 14. The circuit breaker system of claim 13, wherein the short circuit protection unit further comprises a second comparator; The non-inverting input terminal of the second comparator is connected to a second preset voltage, the inverting input terminal of the second comparator is coupled to the output terminal of the current signal processing unit, and the output of the second comparator The terminal is coupled to the first input terminal of the driving unit. 15. The circuit breaker system according to claim 14, wherein the short circuit protection unit further comprises a first OR gate; The output terminals of the first comparator and the second comparator are coupled to the first input terminal of the first OR gate; The second input end of the first OR gate is coupled to its output end, and the output end of the first OR gate is connected to the first input end of the driving unit.