CN117116689A

CN117116689A - Switching circuit and relay system

Info

Publication number: CN117116689A
Application number: CN202311241273.0A
Authority: CN
Inventors: 欧佳嵘; 朱可; 沈超; 洪传生; 王相云; 王加春; 奉石坚; 陈拙
Original assignee: Shanghai Chint Intelligent Technology Co Ltd
Current assignee: Shanghai Chint Intelligent Technology Co Ltd
Priority date: 2023-09-22
Filing date: 2023-09-22
Publication date: 2023-11-24

Abstract

The application provides a switching circuit and a relay system, the switching circuit includes: a solid state switch module; the mechanical switch module is connected with the solid-state switch module in parallel; the input end of the interlocking control module is connected with the mechanical switch module, and the output end of the interlocking control module is connected with the control end of the solid-state switch module; the interlocking control module is used for controlling the solid-state switch module to be closed for preset time when the mechanical switch module starts to be opened, and the preset time is greater than or equal to the opening time of the mechanical switch module. The application can avoid the phenomenon of high-voltage arc generated in the mechanical switch disconnection process caused by the occurrence of switch logic errors of the mechanical switch and the solid-state switch.

Description

Switching circuit and relay system

Technical Field

The application relates to the technical field of electrical equipment, in particular to a switching circuit and a relay system.

Background

At present, because the fault current has the characteristics of high rising speed, large amplitude and the like when the power grid has short circuit fault, if a mechanical breaker is adopted to cut off the fault current, high-voltage electric arcs can be generated at the moment of switching off, electric equipment can be burnt even when serious, and a solid-state breaker (SolidStateCircuit Breaker, SSCB) is used as a special breaker adopting a power tube device as a switching-off element, compared with the traditional mechanical breaker, the solid-state breaker has the characteristics of no electric arc phenomenon and high switching-off speed, and therefore, the solid-state breaker becomes a research hotspot in the field of the current breaker.

However, the circuit breaker using the simple power tube device as a switch has the risk of breakdown of the power tube when short circuit occurs, so that a circuit control scheme of using a mechanical switch and a solid-state switch in parallel is more and more commonly used. In the related art, the mechanical switch and the solid-state switch need to be triggered to be turned on and off by an independent power supply and a trigger circuit, but this easily causes a logic error of the mechanical switch and the solid-state switch, for example, the solid-state switch is turned off before the mechanical switch is turned off, so that a high voltage arc phenomenon still occurs when the mechanical switch is turned off.

Disclosure of Invention

The application provides a switching circuit and a relay system, and aims to solve the technical problem that the existing mechanical switch and solid-state switch are prone to switch logic errors.

In a first aspect, the present application provides a switching circuit comprising:

a solid state switch module;

the mechanical switch module is connected with the solid-state switch module in parallel;

the input end of the interlocking control module is connected with the mechanical switch module, and the output end of the interlocking control module is connected with the control end of the solid-state switch module;

the interlocking control module is used for controlling the solid-state switch module to be closed for preset time when the mechanical switch module starts to be opened, and the preset time is greater than or equal to the opening time of the mechanical switch module.

In some embodiments, the mechanical switch module includes an electromagnetic coil and an induction coil coupled to the electromagnetic coil;

the input end of the interlocking control module is connected with the induction coil, and when the induction coil generates induction current, the interlocking control module provides control voltage for the control end of the solid-state switch module.

In some embodiments, the interlock control module includes a rectifier module and a voltage regulator module;

the first input end and the second input end of the rectifying module are respectively connected with two ends of the induction coil, the output end of the rectifying module is connected with the input end of the voltage stabilizing module, and the output end of the voltage stabilizing module is connected with the control end of the solid-state switch module.

In some embodiments, the rectifying module includes a rectifying bridge and the voltage stabilizing module includes a first capacitor;

the first input end and the second input end of the rectifier bridge are respectively connected with two ends of the induction coil;

the first output end of the rectifier bridge is connected with the first polar plate of the first capacitor, and the second output end of the rectifier bridge is connected with the second polar plate of the first capacitor;

the first polar plate of the first capacitor is grounded, and the second polar plate of the first capacitor is connected with the control end of the solid-state switch module.

In some embodiments, the solid-state switch module further comprises a first MOS transistor and a second MOS transistor;

The source electrode of the first MOS tube is connected with the source electrode of the second MOS tube, and the grid electrodes of the first MOS tube and the second MOS tube are connected with the output end of the interlocking control module;

the drain electrode of the first MOS tube is connected with the power input end of the mechanical switch module, and the drain electrode of the second MOS tube is connected with the power output end of the mechanical switch module.

In some embodiments, the solid state switch module further comprises a first resistor;

the first end of the first resistor is connected to a first node between the source electrode of the first MOS tube and the source electrode of the second MOS tube, and the second end of the first resistor is connected with the output end of the interlocking control module;

the grid electrodes of the first MOS tube and the second MOS tube are connected with the second end of the first resistor, and the first node is grounded.

In some embodiments, the switching circuit further comprises a current detection module configured to detect a line current magnitude of the power line, and a voltage control module having an input connected to an output of the current detection module;

when the line current is smaller than a first preset value, the voltage control module provides a first preset voltage for the electromagnetic coil; when the line current is greater than or equal to a first preset value, the voltage control module provides a second preset voltage for the electromagnetic coil;

The second preset voltage is greater than the first preset voltage, so that the disconnection speed of the mechanical switch module is increased when the line current is greater than or equal to the first preset value.

In some embodiments, the voltage control module includes a short circuit determination module and a voltage input module;

the input end of the short circuit judging module is connected with the output end of the current detecting module, and the input end of the voltage input module is connected with the output end of the short circuit judging module;

when the line current is greater than or equal to a first preset value, the short circuit judging module outputs a control signal, and the voltage input module provides a second preset voltage for the electromagnetic coil according to the control signal.

In some embodiments, the voltage input module includes a first switch and the short circuit determination module includes a first comparator;

one end of the first switch is connected with a second preset voltage, and the other end of the first switch is connected with the electromagnetic coil;

the non-inverting input end of the first comparator is connected with the output end of the current detection module, the inverting input end of the first comparator is connected with a first comparison voltage, and the output end of the first comparator is connected with a first switch.

In some embodiments, the short circuit determination module further comprises a second comparator;

the inverting input end of the second comparator is connected with the output end of the current detection module, the non-inverting input end of the first comparator is connected with the second comparison voltage, and the output end of the second comparator is connected with the first switch control end.

In some embodiments, the voltage control module further comprises a signal holding module;

the input end of the signal holding module is connected with the output end of the short circuit judging module, and the output end of the signal holding module is connected with the input end of the voltage input module;

when the line current is greater than or equal to a first preset value, the short circuit judging module outputs a first control signal in a first time period, and the signal holding module outputs a second control signal in a second time period according to the first control signal, wherein the second time period is greater than the first time period.

In some embodiments, the signal holding module comprises a first or gate;

the first input end and the second input end of the first OR gate are connected with the output end of the short circuit judging module, and the output end of the first OR gate is connected with the input end of the voltage input module;

the first input end and/or the second input end of the first OR gate are/is connected with the output end.

In some embodiments, the electromagnetic coil includes a first coil and a second coil;

the first coil is configured to control the mechanical switch module to be closed after being electrified, the second coil is configured to control the mechanical switch module to be opened after being electrified, and the induction coil is coupled with the second coil;

when the line current is smaller than a first preset value, the voltage control module provides a first preset voltage for the first coil and the second coil; when the line current is greater than or equal to a first preset value, the voltage control module provides a second preset voltage to the first coil and the second coil.

In some embodiments, the switching circuit further comprises a first control switch and a second control switch;

the first end of the first coil and the first end of the second coil are connected with the voltage control module;

the first end of the first control switch is connected with the second end of the first coil, and the second end of the first control switch is grounded; the first end of the second control switch is connected with the second end of the second coil, and the second end of the second control switch is grounded.

In some embodiments, the control terminal of the second control switch is connected to the voltage control module;

when the line current is greater than or equal to the first preset value, the voltage control module provides a second preset voltage for the second coil and controls the second control switch to be repeatedly opened and closed, so that the second coil is enabled to be electrified with pulse current.

In a second aspect, the application provides a relay system comprising a switching circuit as in the first aspect.

According to the application, the mechanical switch module and the solid switch module are controlled in an associated manner through the interlocking control module, when the mechanical switch module starts to be opened, the solid switch module is closed for a preset time, and the preset time is greater than or equal to the opening time of the mechanical switch module, so that in the opening process of the mechanical switch module, a power line can flow through the solid switch modules which are connected in parallel and in the closed state, and the phenomenon that high-voltage arc is generated in the opening process of the mechanical switch due to logic errors of the mechanical switch and the solid switch is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic block diagram of a switching circuit provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of another module of a switching circuit provided in an embodiment of the present application;

FIG. 3 is a schematic diagram of another module of the switching circuit provided in an embodiment of the present application;

FIG. 4 is a schematic circuit diagram of a switching circuit provided in an embodiment of the present application;

FIG. 5 is a schematic diagram of another module of a switching circuit provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of another module of a switching circuit provided in an embodiment of the present application;

FIG. 7 is another schematic circuit diagram of a switching circuit provided in an embodiment of the present application;

FIG. 8 is another schematic circuit diagram of a switching circuit provided in an embodiment of the present application;

FIG. 9 is another schematic circuit diagram of a switching circuit provided in an embodiment of the present application;

FIG. 10 is a schematic diagram of another module of a switching circuit provided in an embodiment of the present application;

FIG. 11 is another circuit schematic of a switching circuit provided in an embodiment of the present application;

FIG. 12 is a schematic diagram of another module of the switching circuit provided in an embodiment of the present application;

FIG. 13 is a schematic diagram of another module of a switching circuit provided in an embodiment of the present application;

fig. 14 is another circuit schematic of a switching circuit provided in an embodiment of the present application.

The device comprises a mechanical switch module 10, a solid-state switch module 20, an interlocking control module 30, an electromagnetic coil 11, an induction coil 12, a switch mechanism 13, a rectifying module 31, a voltage stabilizing module 32, a first coil 111, a second coil 112, a current detection module 40, a voltage control module 50, a short circuit judgment module 51, a voltage input module 52, a signal holding module 53, a voltage-controlled oscillator 54 and a control module 60;

the rectifier bridge D12, the first capacitor C4, the first MOS transistor Q5, the second MOS transistor Q6, the first resistor R16 and the first node M1;

the device comprises a first switch S1, a first comparator U2, a second comparator U3, a first PMOS tube Q1, a first NMOS tube Q2, a first OR gate U1, a first control switch Q3, a second control switch Q4, a first comparison voltage V01 and a second comparison voltage V02.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to fall within the scope of the application.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present application, the term "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described as "exemplary" in this disclosure is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the application. In the following description, details are set forth for purposes of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known structures and processes have not been described in detail so as not to obscure the description of the application with unnecessary detail. Thus, the present application 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 herein.

The embodiment of the application provides a switching circuit and a relay system, which are respectively described in detail below.

Referring first to fig. 1, fig. 1 shows a schematic block diagram of a switching circuit according to an embodiment of the present application, where the switching circuit includes:

a solid state switch module 20;

A mechanical switch module 10, the mechanical switch module 10 being connected in parallel with the solid state switch module 20;

the input end of the interlocking control module 30 is connected with the mechanical switch module 10, and the output end of the interlocking control module 30 is connected with the control end of the solid-state switch module 20;

the interlock control module 30 is configured to control the solid-state switch module 20 to be turned on for a preset time when the mechanical switch module 10 starts to be turned off, and the preset time is greater than or equal to the turn-off time of the mechanical switch module 10.

Specifically, the solid-state switch module 20 has a transistor with a switching function, for example, the solid-state switch module 20 may include a MOS transistor, an IGBT transistor, or a JEFT transistor, and the on/off control of the current on the power line is implemented by the on/off of the transistor. In some embodiments of the present application, the solid state switch module 20 may include one transistor. In other embodiments of the present application, the solid state switch module 20 may include a plurality of transistors, such as a plurality of MOS transistors in series or parallel.

The mechanical switch module 10 controls the on-off of the power supply line through the switch mechanism 13, thereby realizing the power-on and power-off control of the electrical equipment connected with the power supply line. Wherein the mechanical switch module 10 is connected in parallel with the solid-state switch module 20, that is, when one of the two is in a conductive state, the power line is still capable of transmitting electric energy, for example, when the mechanical switch module 10 is turned off and the solid-state switch module 20 is turned on, the power line is still capable of transmitting electric energy; when both are in the off state, the power supply circuit can stop transmitting the electric energy.

In some embodiments of the present application, the mechanical switch module 10 has a solenoid 11 and a switching mechanism 13 (e.g., a moving contact) for electrically conducting/disconnecting a power line according to on/off of the solenoid 11, and after the coil of the mechanical switch module 10 is energized, the solenoid 11 generates a magnetic force to drive the switching mechanism 13 to be opened or closed.

In some embodiments of the present application, the number of the magnetic coils of the mechanical switch module 10 may be one, and the opening/closing control of the switch mechanism 13 is achieved by controlling the flow direction of the current of the electromagnetic coil 11. For example, when the electromagnetic coil 11 is supplied with a forward current, the electromagnetic coil 11 generates an attracting force to the switch mechanism 13 with a magnet, and the switch mechanism 13 with a magnet is attracted to be closed; for another example, when the electromagnetic coil 11 is supplied with a reverse current, the electromagnetic coil 11 generates a repulsive force to the switch mechanism 13 with a magnet, thereby attracting the switch mechanism 13 with a magnet to be turned off.

In some embodiments of the present application, the number of electromagnetic coils 11 of the mechanical switch module 10 may be two, and one electromagnetic coil 11 generates an attraction force to the switch mechanism 13 with a magnet after being energized, so as to attract the switch mechanism 13 with a magnet and close; the other electromagnetic coil 11 generates a repulsive force to the switch mechanism 13 with the magnet after being energized, thereby repelling and turning off the switch mechanism 13 with the magnet.

The mechanical switch module 10 may be a magnetically held relay, for example. It should be understood that the mechanical switch module 10 according to the present application is not limited to a magnetic latching relay, but may also refer to any electromagnetic relay that requires the electromagnetic coil 11 to be energized to control the disconnection of the circuit.

The interlocking control module 30 can control the solid-state switch module 20 through the off signal interlocking of the mechanical switch module 10, so that the solid-state switch module 20 is in a closed state in the process of opening the mechanical switch module 10, and the phenomenon that high-voltage arc is generated in the process of opening the mechanical switch module 10 is avoided. Wherein the solid-state switch module 20 is controlled to be closed for a preset time when the mechanical switch module 10 starts to be opened, the preset time is greater than or equal to the opening time of the mechanical switch module 10, for example, the opening time of the mechanical switch module 10 is 2ms to 5ms, and the preset time when the mechanical switch module 10 starts to be opened can be set to be 10ms.

It will be appreciated that, for the setting of the preset time, those skilled in the art can adjust according to actual needs, and the present application is not particularly limited herein.

In some embodiments of the present application, the interlock control module 30 may drive the solid state switch according to a control signal of the mechanical switch module 10, for example, a switch (e.g., Q4) control signal that controls the energization of the solenoid 11 to control the solid state switch module 20 to be closed for a preset time. In other embodiments of the present application, the interlock control module 30 may drive the solid state switch module 20 to close for a preset time based on the electromagnetic signal of the electromagnetic coil 11 of the mechanical switch module 10.

In the embodiment of the application, the mechanical switch module 10 and the solid switch module 20 are controlled in an associated manner by the interlocking control module 30, when the mechanical switch module 10 starts to be opened, the solid switch module 20 is closed for a preset time, and the preset time is greater than or equal to the opening time of the mechanical switch module 10, so that in the opening process of the mechanical switch module 10, a power line can flow through the solid switch module 20 which is connected in parallel and is in the closed state, and the phenomenon that a high-voltage arc is generated in the opening process of the mechanical switch due to logic errors of the mechanical switch and the solid switch is avoided.

In some embodiments of the present application, for example, for embodiments in which the interlock control module 30 may drive the solid state switch module 20 to close for a preset time based on the electromagnetic signal of the electromagnetic coil 11 of the mechanical switch module 10, referring to fig. 2, fig. 2 shows another schematic block diagram of the switch circuit in the implementation of the present application, wherein the mechanical switch module 10 includes the electromagnetic coil 11 and the induction coil 12 coupled to the electromagnetic coil 11; the input of the interlock control module 30 is connected to the induction coil 12, and when the induction coil 12 generates an induction current, the interlock control module 30 provides a control voltage to the control terminal of the solid state switch module 20.

It should be noted that, because the electromagnetic coil 11 is coupled to the induction coil 12, when the pulse current is applied to the electromagnetic coil 11, the electromagnetic coil 11 can generate magnetic force and drive the switching mechanism 13 to start to be opened, and meanwhile, the induction coil 12 also generates induction current, so that the interlock control module 30 provides control voltage to the control end of the solid-state switch module 20, and finally drives the solid-state switch to be closed for a preset time, so as to avoid the phenomenon of high-voltage arc generated in the mechanical switch opening process.

In some embodiments of the present application, an ac power source may be provided through which pulsed current is supplied to the solenoid 11. In other embodiments of the present application, a dc power supply and a switch for controlling whether the dc power supply is connected to the electromagnetic coil may be provided, and pulse current may be applied to the electromagnetic coil 11 by repeatedly turning on and off the switch by controlling the switch, for example, as shown in fig. 2, when a dc power VCC is connected to one end of the electromagnetic coil 11, and the other end of the electromagnetic coil 11 is connected to a control switch (Q3, Q4) connected to ground, and pulse current is applied to the electromagnetic coil 11 by repeatedly turning on and off the control switch (Q3, Q4).

In some embodiments of the present application, with continued reference to fig. 3, fig. 3 shows another schematic diagram of a switch circuit in an embodiment of the present application, where the interlock control module 30 includes a rectifying module 31 and a voltage stabilizing module 32; the first input end and the second input end of the rectifying module 31 are respectively connected with two ends of the induction coil 12, the output end of the rectifying module 31 is connected with the input end of the voltage stabilizing module 32, and the output end of the voltage stabilizing module 32 is connected with the control end of the solid-state switch module 20.

Specifically, after the electromagnetic coil 11 is fed with a pulse current, the induction coil 12 will generate a changed induction current, the rectification module 31 can convert the induction current output from two ends of the induction coil 12 into a pulse current with the current direction unchanged, and the voltage stabilizing module 32 can filter the pulse current output from the rectification module 31, so that the pulse current is converted into a direct current, and finally a stable voltage is output, so that the solid-state switch module 20 is controlled by the stable voltage. Illustratively, the rectifying module 31 may include a half-wave rectifying circuit, a full-wave rectifying circuit, a bridge rectifying circuit, or the like; the voltage regulator module 32 may include voltage-regulating electronic components such as capacitors or inductors.

As an exemplary embodiment, referring to fig. 4, fig. 4 shows a schematic circuit diagram of a switching circuit according to an embodiment of the present application, wherein a rectifying module 31 includes a rectifying bridge D12, and a voltage stabilizing module 32 includes a first capacitor C4; the first input end and the second input end of the rectifier bridge D12 are respectively connected with two ends of the induction coil 12; the first output end of the rectifier bridge D12 is connected with the first polar plate of the first capacitor C4, and the second output end of the rectifier bridge D12 is connected with the second polar plate of the first capacitor C4; the first electrode plate of the first capacitor C4 is grounded, and the second electrode plate of the first capacitor C4 is connected to the control end of the solid-state switch module 20.

It should be noted that, the rectifier bridge D12 may convert the two ends of the induction coil 12 to pulse current signals, and since the first output end of the rectifier bridge D12 is connected to the first electrode plate of the first capacitor C4, the second output end of the rectifier bridge D12 is connected to the second electrode plate of the first capacitor C4, when the pulse current signals are rising edges, the pulse current signals charge the first capacitor C4, and when the pulse current signals are falling edges, the first capacitor C4 may discharge, so as to convert the pulse current signals into smooth direct current signals, and further control the solid-state switch module 20 by using stable voltages.

It will be appreciated that the pulse signal may also be filtered using an inductor and a smoothed voltage signal may be obtained, for example, an inductor may be connected in series with the first output terminal of the rectifier bridge D12, and the pulse current signal may be filtered using the inductor.

In some embodiments of the present application, with continued reference to fig. 4, the voltage stabilizing module 32 may further include a voltage stabilizing diode D11, where the voltage stabilizing diode D11 is connected in parallel with the first capacitor C4, so that a voltage difference across the first capacitor C4 is kept at a certain threshold (e.g. 5V), so as to avoid that the first capacitor C4 provides an excessive voltage to the control terminal (e.g. the gates of the first MOS transistor Q5 and the second MOS transistor Q6) of the solid-state switch module 20, which causes a breakdown phenomenon of the transistors of the solid-state switch module 20.

In some embodiments of the present application, with continued reference to fig. 4, the solid-state switch module 20 further includes a first MOS transistor Q5 and a second MOS transistor Q6; the source electrode of the first MOS tube Q5 is connected with the source electrode of the second MOS tube Q6, and the grid electrodes of the first MOS tube Q5 and the second MOS tube Q6 are connected with the output end of the interlocking control module 30; the drain electrode of the first MOS tube Q5 is connected with the power input end of the mechanical switch module 10, and the drain electrode of the second MOS tube Q6 is connected with the power output end of the mechanical switch module 10.

Specifically, after the interlock control module 30 converts the induced current of the induction coil 12 into a control signal, the gates of the first MOS transistor Q5 and the second MOS transistor Q6 receive the control signal, so as to drive the first MOS transistor Q5 and the second MOS transistor Q6 to be turned on, and the current of the power line can flow through the first MOS transistor Q5 and the second MOS transistor Q6 during the disconnection process of the mechanical switch module 10, so as to avoid the high voltage arc phenomenon generated during the disconnection process of the mechanical switch module 10.

It will be appreciated that the solid state switch module 20 may also be provided with a greater number of switches, such as MOS, IGBT or JEFT transistors, etc.

In some embodiments of the present application, with continued reference to fig. 4, the solid-state switch module 20 further includes a first resistor R16; the first end of the first resistor R16 is connected to a first node M1 between the source electrode of the first MOS tube Q5 and the source electrode of the second MOS tube Q6, and the second end of the first resistor R16 is connected with the output end of the interlocking control module 30; the gates of the first MOS transistor Q5 and the second MOS transistor Q6 are connected with the second end of the first resistor R16, and the first node M1 is grounded. That is, the first end of the first resistor R16 is connected to the source of the first MOS transistor Q5 and the source of the second MOS transistor Q6 and grounded, and the gates of the first MOS transistor Q5 and the second MOS transistor Q6 are connected to the second end of the first resistor R16, so that the source and the gate of the first MOS transistor Q5 and the second MOS transistor Q6 can maintain a fixed voltage difference, so that after the first resistor R16 receives the voltage signal of the first capacitor C4, the first MOS transistor Q5 and the second MOS transistor Q6 can be driven to be turned on by the voltage difference between the source and the gate; meanwhile, since the first end of the first resistor R16 is grounded, the charges stored in the first capacitor C4 can be slowly released through the first resistor R16, and the gate voltages of the first MOS transistor Q5 and the second MOS transistor Q6 are gradually reduced, and finally after the charges stored in the first capacitor C4 are released, the first MOS transistor Q5 and the second MOS transistor Q6 are disconnected, and the first capacitor C4 releases the charges to reduce the voltage, so that the first MOS transistor Q5 and the second MOS transistor Q6 can be kept in a conducting state for a preset time.

As can be appreciated by those skilled in the art, by adjusting the capacitance value of the first capacitor C4 and the resistance value of the first resistor R16, it is ensured that the first MOS transistor Q5 and the second MOS transistor Q6 maintain the on state for a preset time, that is, the first MOS transistor Q5 and the second MOS transistor Q6 maintain the on state during the disconnection process of the mechanical switch module 10, so as to ensure that no arc is generated during the disconnection process of the mechanical switch module 10.

Since the induction coil 12 is coupled to the electromagnetic coil 11, the induction coil 12 generates an opposite magnetic field after the electromagnetic coil 11 is energized, so that the magnetic force applied to the switching mechanism 13 is weakened, and the off time of the mechanical switching module 10 is prolonged. This phenomenon does not have an excessive effect on the normal switching process, but if the circuit sends a short-circuit fault, the mechanical switch module 10 is opened at a relatively high speed, which is liable to cause damage to electrical equipment. To solve this problem, please continue to refer to the following.

In some embodiments of the present application, with continued reference to fig. 5, fig. 5 shows another schematic block diagram of a switching circuit according to an embodiment of the present application, where the switching circuit further includes a current detection module 40 and a voltage control module 50, the current detection module 40 is configured to detect a line current of a power line, and an input terminal of the voltage control module 50 is connected to an output terminal of the current detection module 40; when the line current is less than the first preset value, the voltage control module 50 provides the first preset voltage V1 to the electromagnetic coil 11; when the line current is greater than or equal to the first preset value, the voltage control module 50 provides a second preset voltage V2 to the electromagnetic coil 11; the second preset voltage V2 is greater than the first preset voltage V1, so as to increase the turn-off speed of the mechanical switch module 10 when the line current is greater than or equal to the first preset value.

Specifically, the current detection module 40 may detect the line current of the power line, so as to determine whether there is a fault phenomenon of the electrical device connected to the power line, for example, a short circuit current occurring when a circuit is short-circuited, or an overload current caused by a decrease in load impedance, etc. Generally, the output signal of the current detection module 40 is a voltage signal, so as to determine whether the power circuit is overloaded or shorted by the comparator of the voltage control module 50.

In some embodiments of the present application, the current detection module 40 may be connected in series with the power line to measure the line current on the power line in a direct measurement manner, for example, by connecting a fixed resistor in series with the power line and measuring the voltage across the fixed resistor to obtain the line current on the power line. In some embodiments of the present application, the current detection module 40 may also be sleeved on the power line to obtain the line current on the power line in an indirect measurement manner, for example, the current detection module 40 may include a current transformer, and the current on the power line is indirectly measured through the current transformer.

It will be appreciated that the current detection module 40 may also use hall, TMR (tunnel magnetoresistance), fluxgate or rogowski coil principles to perform current measurement; alternatively, the current detection module 40 may be implemented by a shunt.

The voltage control module 50 may control the magnitude of the voltage input to the electromagnetic coil 11 of the mechanical switching module 10 according to the magnitude of the line current. Wherein, when the line current is less than a first preset value (e.g., 5A), the voltage control module 50 provides a first preset voltage V1 (e.g., 5V) to the electromagnetic coil 11; when the line current is greater than or equal to the first preset value (e.g. 5A), the voltage control module 50 provides the electromagnetic coil 11 with the second preset voltage V2 (e.g. 10V), and when the line current is too large, the electromagnetic coil 11 can generate a larger magnetic force by the second preset voltage V2 with the larger voltage, so that the opening speed of the switching mechanism 13 is increased, and finally the purpose of short-circuit protection of the electrical equipment is achieved.

In some embodiments of the present application, referring to fig. 6, fig. 6 shows another schematic block diagram of a switching circuit in an embodiment of the present application, where a voltage control module 50 includes a short circuit judging module 51 and a voltage input module 52; an input end of the short circuit judging module 51 is connected with an output end of the current detecting module 40, and an input end of the voltage input module 52 is connected with an output end of the short circuit judging module 51; when the line current is greater than or equal to the first preset value, the short circuit judging module 51 outputs a control signal, and the voltage input module 52 provides the second preset voltage V2 to the electromagnetic coil 11 according to the control signal, so that the mechanical switch module 10 is rapidly opened.

As an exemplary example, referring to fig. 7, fig. 7 shows a schematic circuit diagram of a switching circuit in an embodiment of the present application, where the voltage input module 52 includes a first switch S1, one end of the first switch S1 is connected to a second preset voltage V2, the other end is connected to the electromagnetic coil 11, when the line current is greater than or equal to a first preset value, the short circuit judging module 51 outputs a control signal, and the first switch S1 is closed under the action of the control signal, so that the electromagnetic coil 11 is connected to the second preset voltage V2.

With continued reference to fig. 7, the short circuit determining module 51 may include a first comparator U2, where a non-inverting input terminal of the first comparator U2 is connected to the output terminal of the current detecting module 40, an inverting input terminal of the first comparator U2 is connected to the first comparison voltage V01, and an output terminal of the first comparator U2 is connected to the first switch S1 in a control manner. The current detection module 40 detects the line current of the power line and outputs a corresponding voltage signal, and the voltage signal is compared with a first comparison voltage V01 signal by the first comparator U2 to output a control signal. For example, when the first comparison voltage V01 is 2V and the line current is equal to the first preset value, the voltage signal output by the output end of the current detection module 40 is 2.1V, and then the voltage of the non-inverting input end of the first comparator U2 is greater than the voltage of the inverting input end, and the output end of the first comparator U2 outputs a high-level signal, so that the first switch S1 can be controlled to be closed and the electromagnetic coil 11 is connected to the second preset voltage V2.

In some embodiments of the present application, with continued reference to fig. 7, the voltage input module 52 further includes a single-phase diode D11, the positive electrode of the single-phase diode D11 is connected to the first preset voltage V1, and the negative electrode of the single-phase diode D11 is connected to the electromagnetic coil 11. When the first switch S1 is closed, the electromagnetic coil 11 is connected to the second preset voltage V2, and the current cannot flow backward to the first preset voltage V1 due to the action of the single-phase diode D11; conversely, when the first switch S1 is turned off, the electromagnetic coil 11 is re-connected to the first preset voltage V1.

It will be appreciated that the voltage input module 52 may also include two switches to control the solenoid 11 to switch on either the first preset voltage V1 or the second preset voltage V2. For example, referring to fig. 8, fig. 8 shows another schematic circuit diagram of a switching circuit in an embodiment of the present application, where the voltage input module 52 includes a first switch S1 and a second switch S2, one end of the first switch S1 is connected to a second preset voltage V2, and the other end is connected to the electromagnetic coil 11; one end of the second switch S2 is connected to the first preset voltage V1, and the other end of the second switch S is connected with the electromagnetic coil 11. When the high level signal output by the first comparator U2 controls the first switch S1 to be closed and the second switch S2 to be opened, the electromagnetic coil 11 is connected to a second preset voltage V2; conversely, when the first comparator U2 outputs a low level signal to control the first switch S1 to be turned off and the second switch S2 to be turned on, the electromagnetic coil 11 is connected to the first preset voltage V1.

The first switch S1 and the second switch may be transistors with switching functions, such as MOS transistors, IGBT transistors, or transistors, for example.

In some embodiments of the present application, with continued reference to fig. 9, fig. 9 shows another schematic circuit diagram of a switch circuit in an embodiment of the present application, where the short circuit determining module 51 further includes a second comparator U3; the inverting input end of the second comparator U3 is connected with the output end of the current detection module 40, the non-inverting input end of the first comparator U2 is connected with the second comparison voltage V02, and the output end of the second comparator U3 is connected with the control end of the first switch S1.

In the double-sided power network, there are two directions of short-circuit current, for example, the short-circuit current flows from the bus bar to the line, and there may be short-circuit current flowing from the line to the bus bar. In the above embodiment, when the voltage of the signal output by the current detection module 40 is greater than the first comparison voltage V01, it is indicated that the current detection module 40 recognizes the forward fault current (such as the forward short-circuit current or the overload current) in the double-sided power network, and the first comparator U2 outputs the high-level signal, so that the electromagnetic coil 11 of the mechanical switch module 10 can be controlled to be connected to the second preset voltage V2 and be rapidly disconnected, so as to realize the forward short-circuit current protection; when the voltage of the output signal of the current detection module 40 is smaller than the second comparison voltage V02, it is indicated that the current detection module 40 recognizes the reverse fault current in the dual-side power network, and the second comparator U3 outputs a high-level signal at this time, and can also control the electromagnetic coil 11 of the mechanical switch module 10 to be connected to the second preset voltage V2 and be rapidly disconnected, so as to realize the reverse short-circuit current protection.

That is, on the one hand, the above-mentioned short circuit judging module 51 can realize the recognition judgment and short circuit protection of the short circuit current in two directions, and on the other hand, the position of the short circuit fault device can be rapidly judged by using the signals output by the first comparator U2 and the second comparator U3 in the double-sided power network, and the specific short circuit fault device is closer to the power supply on which side, thereby facilitating the fast positioning and rush repair of the fault position by the maintainer.

Illustratively, the first comparison voltage V01 is 3.5V, the second comparison voltage V02 is 1.5V, and when the voltage of the output signal of the current detection module 40 is 2.5V, the first comparator U2 and the second comparator U3 both output low-level signals at this time, which indicates that the working current in the power supply loop is normal, and no fault current exists; when the voltage of the output signal of the current detection module 40 is 3.8V, the first comparator U2 outputs a high level signal, and the second comparator U3 outputs a low level signal, which indicates that a forward fault current exists in the power supply loop; when the voltage of the output signal of the current detection module 40 is 1.3V, the first comparator U2 outputs a low level signal, and the second comparator U3 outputs a high level signal, which indicates that a reverse fault current exists in the power supply loop.

In some embodiments of the present application, the current detection module 40 may detect the current in two directions by using a hall type current sensor of a unipolar power source, for example, a hall type CC6920 hall sensor of the company, inc, which may output a positive voltage signal when detecting both the forward fault current and the reverse fault current, so that the first comparator U2 and the second comparator U3 may determine that they are within a positive level threshold. In some embodiments of the present application, the current detection module 40 may also employ a hall type current sensor of a bipolar power source to detect current in both directions.

In some embodiments of the present application, with continued reference to fig. 10, fig. 10 shows another block diagram of a switching circuit in an embodiment of the present application, where the voltage control module 50 further includes a signal holding module 53; the input end of the signal holding module 53 is connected with the output end of the short circuit judging module 51, and the output end of the signal holding module 53 is connected with the input end of the voltage input module 52; when the line current is greater than or equal to the first preset value, the short circuit judgment module 51 outputs a first control signal for a first period of time, and the signal holding module 53 outputs a second control signal for a second period of time according to the first control signal, the second period of time being greater than the first period of time.

It should be noted that the short-circuit fault may occur instantaneously and then be eliminated, so that the short-circuit current may suddenly rise instantaneously and then fluctuate around the first preset value, and thus the first switch S1 may not be stably controlled to be kept closed only by the signal output from the comparator of the short-circuit judging module 51. In the above embodiment, the signal holding module 53 may output the second control signal in the second period according to the first control signal, and since the second period is greater than the first period, the signal holding module 53 may output the stable second control signal, and make the first switch S1 be stably in the closed state until the mechanical switch module 10 is completely opened, so as to avoid the phenomenon that the first switch S1 is repeatedly turned on and off due to the unstable control signal when the short circuit phenomenon occurs, and finally, the mechanical switch module 10 is repeatedly turned off and on.

Preferably, the second period of time is greater than the time it takes for the mechanical switch module 10 to switch from the closed state to the open state to ensure that the mechanical switch module 10 is fully opened after the occurrence of a short circuit current.

As an exemplary embodiment, referring to fig. 11, fig. 11 shows another schematic circuit diagram of a switch circuit in an embodiment of the present application, where the signal holding module 53 includes a first or gate U1; the first input end and the second input end of the first OR gate U1 are connected with the output end of the short circuit judging module 51, and the output end of the first OR gate U1 is connected with the input end of the voltage input module 52; the first input end and/or the second input end of the first or gate U1 are/is connected with the output end.

Specifically, after the output ends of the first comparator U2 and the second comparator U3 output the high-level signal, the first input end and the second input end of the first or gate U1 receive the high-level signal, and then the output end of the first or gate U1 outputs the high-level signal, and the first input end, the second input end and the output end of the first or gate U1 continuously input/output the high-level signal due to the coupling of the first input end and the second input end of the first or gate U1 to the output end of the first or gate U1, so that the first or gate U1 is in a self-locking state, the output end of the first or gate U1 continuously outputs the high-level signal and is not affected by the subsequent output signals of the output ends of the first comparator U2 and the second comparator U3, thereby avoiding the phenomenon that the short circuit cannot be effectively detected and judged under the condition that the short circuit current is instantaneously increased and rapidly decreased.

In some embodiments of the present application, with continued reference to fig. 11, the first switch S1 includes a first PMOS transistor Q1, and the voltage input module 52 further includes a first NMOS transistor Q2; the source electrode of the first PMOS tube Q1 is connected with a second preset voltage V2, the drain electrode of the first PMOS tube Q1 is connected with the electromagnetic coil 11, and the grid electrode of the first PMOS tube Q1 is connected with the drain electrode of the first NMOS tube Q2; the drain electrode of the first NMOS tube Q2 is grounded, and the grid electrode of the first NMOS tube Q2 is connected with the output end of the first comparator U2. Specifically, when the line current is greater than or equal to a first preset value and the first or gate U1 outputs a high-level signal, the first NMOS transistor Q2 is turned on, so that the gate of the first PMOS transistor Q1 is grounded, and further the first PMOS transistor Q1 is turned on, and finally the electromagnetic coil 11 of the mechanical switch module 10 is connected to a second preset voltage V2 and quick breaking is achieved.

It will be appreciated that the voltage input module 52 may also include a greater number of switches, such as a greater number of MOS transistors, or IGBT transistors, etc., to indirectly control the first switch S1 to be turned on or off.

In some embodiments of the present application, for example, for embodiments in which the mechanical switch module 10 is a magnetic latching relay, with continued reference to fig. 12, fig. 12 shows another schematic circuit diagram of a switching circuit in an embodiment of the present application, wherein the electromagnetic coil 11 includes a first coil 111 and a second coil 112, the first coil 111 is configured to control the mechanical switch module 10 to be closed after being energized, the second coil 112 is configured to control the mechanical switch module 10 to be opened when being energized, and the inductive coil 12 is coupled with the second coil 112; when the line current is less than the first preset value, the voltage control module 50 provides a first preset voltage V1 to the first coil 111 and the second coil 112; when the line current is greater than or equal to the first preset value, the voltage control module 50 provides a second preset voltage V2 to the first coil 111 and the second coil 112. That is, when the line current is small, the normal opening and closing processes of the mechanical switch module 10 are controlled by the first preset voltage V1; when the line current is larger, the opening and closing processes of the mechanical switch module 10 are controlled by the second preset voltage V2, so as to achieve the purpose of quick opening when the line current is abnormal.

In some embodiments of the present application, with continued reference to fig. 12, the switching circuit further includes a first control switch Q3 and a second control switch Q4; the first end of the first coil 111 and the first end of the second coil 112 are connected with the voltage control module 50; a first end of the first control switch Q3 is connected to a second end of the first coil 111, and a second end of the first control switch Q3 is grounded; the first terminal of the second control switch Q4 is connected to the second terminal of the second coil 112, and the second terminal of the second control switch Q4 is grounded.

It should be noted that, since the first end of the first coil 111 and the first end of the second coil 112 are connected to the voltage control module 50, the first end of the first coil 111 and the first end of the second coil 112 may be connected to the first preset voltage V1 or the second preset voltage V2 under the control of the voltage control module 50, and whether the second end of the first coil 111 and the second end of the second coil 112 form a loop is controlled by the first control switch Q3 and the second control switch Q4 respectively, and finally the purpose of opening and closing control of the mechanical switch module 10 is achieved through the first control switch Q3 and the second control switch Q4. For example, when the voltage control module 50 supplies the first preset voltage V1 to the first coil 111 and the second coil 112 and the first control switch Q3 is closed, both ends of the first coil 111 form a loop so that the switching mechanism 13 can be controlled to be closed; for another example, when the voltage control module 50 supplies the second preset voltage V2 to the first and second coils 111 and 112 and the second control switch Q4 is closed, both ends of the second coil 112 form a loop so that the switching mechanism 13 can be controlled to be rapidly opened.

The first control switch Q3 and the second control switch Q4 may be, for example, MOS transistors, IGBT transistors, or the like.

In some embodiments of the present application, for facilitating control of the first control switch Q3 and the second control switch Q4, with continued reference to fig. 13, fig. 13 shows another schematic block diagram of a switching circuit in an embodiment of the present application, where the switching circuit further includes a control module 60, a first output terminal of the control module 60 is connected to a control terminal of the first control switch Q3, and a second output terminal of the control module 60 is connected to a control terminal of the second control switch Q4. Specifically, the control module 60 may send control signals to the control end of the first control switch Q3 and the control end of the second control switch Q4, so as to control the first control switch Q3 and the second control switch Q4 to be opened or closed, and further control the mechanical switch module 10 to perform opening and closing.

Illustratively, the control signal may be a PWM signal or a clock signal, for example, when the control module 60 is a single-chip microcomputer, the PWM signal is output through a PWM port of the single-chip microcomputer; for another example, the control unit may include a triangle wave or saw tooth wave generator, and the high frequency modulation wave is generated using the triangle wave or saw tooth wave generator and then the PWM signal is generated via the comparator.

In some embodiments of the present application, the control module 60 is coupled to the current detection module 40 to facilitate acquisition of line current data for the power line.

In some embodiments of the present application, with continued reference to fig. 13, the control terminal of the second control switch Q4 is connected to the voltage control module 50, when the line current is greater than or equal to the first preset value, the voltage control module 50 provides the second preset voltage V2 to the second coil 112 and controls the second control switch Q4 to be repeatedly opened and closed, so that the second coil 112 is led in with the pulse current to control the mechanical switch module 10 to be opened, and the induction coil 12 is caused to generate the induction current and control the solid switch module 20 to be closed, and finally the mechanical switch module 10 is controlled to be opened quickly directly by the voltage control module 50, and the solid switch module 20 is kept in the closed state during the opening process of the mechanical switch module 10.

As an exemplary example, referring to fig. 14, fig. 14 shows another circuit schematic of the switching circuit in the embodiment of the present application, the voltage control module 50 further includes a voltage-controlled oscillator 54, an input end of the voltage-controlled oscillator 54 is connected to an output end of the first or gate U1, an output end of the voltage-controlled oscillator 54 is connected to a control end of the second control switch Q4, when the first or gate U1 outputs a high level signal, the voltage-controlled oscillator 54 outputs a pulse signal to control the second control switch Q4 to be repeatedly opened and closed, and meanwhile, the second coil 112 is also connected to a second preset voltage V2, so that the second coil 112 is connected to the pulse current to control the mechanical switch module 10 to be opened, and the induction coil 12 generates an induction current and controls the solid switch module 20 to be closed.

It will be appreciated that referring to fig. 14, the input terminal of the voltage controlled oscillator 54 may also be connected to the output terminal of the first comparator U2 or the second comparator U3, and the voltage controlled oscillator 54 may output a pulse signal by using a high level signal provided by the output terminal of the first comparator U2 or the second comparator U3.

In some embodiments of the present application, the control module 60 may be further connected to the output terminal of the first or gate U1, so as to determine whether the electromagnetic coil 11 of the circuit breaker is connected to the first preset voltage V1 or the second preset voltage V2 according to the high-low level signal output by the first or gate U1. In some embodiments of the present application, the control module 60 may be further connected to the first input terminal and the second input terminal of the first or gate U1, so as to output a low level signal through the control module 60 and enable the first or gate U1 to release the self-locking state.

It should be noted that the foregoing description of the switching circuit is for clarity of illustrating the implementation verification process of the present application, and those skilled in the art may also make equivalent modification designs under the guidance of the present application, for example, referring to fig. 10, the short circuit judging module 51 may further set capacitors C2 and C3 for voltage stabilization, and set single-phase diodes D6 and D10 to prevent current backflow, and may set divided voltages R5, R9, R13 and R14 to generate a first comparison voltage V01 and a second comparison voltage V02; for another example, referring to fig. 14, the signal holding module 53 may further provide a capacitor C1 for voltage stabilization, and a single-phase diode D4 to prevent current from flowing backward; for another example, the voltage input module 52 may further include R1 for maintaining a voltage difference between the source and the gate of the first PMOS transistor Q1, R4 for maintaining a voltage difference between the source and the gate of the first NMOS transistor Q2, a capacitor C for voltage regulation, and the like.

Also, it should be noted that "connected" in embodiments of the present application is understood to mean electrically connected, and that two electrical components may be connected directly or indirectly between two electrical components. For example, a may be directly connected to B, or indirectly connected to B via one or more other electrical components.

Further, in order to better implement the switching circuit in the embodiment of the present application, the present application further provides a relay control system based on the switching circuit, where the relay control system includes the switching circuit in any one of the embodiments described above. Because the relay control system in the embodiment of the application is provided with the switch circuit in the embodiment, the relay control system has all the beneficial effects of the switch circuit and is not repeated here.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and the portions of one embodiment that are not described in detail in the foregoing embodiments may be referred to in the foregoing detailed description of other embodiments, which are not described herein again.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements and adaptations of the application may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within the present disclosure, and therefore, such modifications, improvements, and adaptations are intended to be within the spirit and scope of the exemplary embodiments of the present disclosure.

Meanwhile, the present application uses specific words to describe embodiments of the present application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the application. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the application may be combined as suitable.

Similarly, it should be noted that in order to simplify the description of the present disclosure and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure, however, is not intended to imply that more features than are required by the subject application. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations in some embodiments for use in determining the breadth of the range, in particular embodiments, the numerical values set forth herein are as precisely as possible.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited herein is hereby incorporated by reference in its entirety except for any application history file that is inconsistent or otherwise conflict with the present disclosure, which places the broadest scope of the claims in this application (whether presently or after it is attached to this application). It is noted that the description, definition, and/or use of the term in the appended claims controls the description, definition, and/or use of the term in this application if there is a discrepancy or conflict between the description, definition, and/or use of the term in the appended claims.

The above describes in detail a switching circuit and a relay system provided by the embodiments of the present application, and specific examples are applied herein to illustrate the principles and embodiments of the present application, and the above description of the embodiments is only for helping to understand the method and core ideas of the present application; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in light of the ideas of the present application, the present description should not be construed as limiting the present application.

Claims

1. A switching circuit, comprising:

a mechanical switch module;

the solid-state switch module is connected with the mechanical switch module in parallel;

2. The switching circuit of claim 1 wherein the mechanical switching module comprises an electromagnetic coil and an induction coil coupled to the electromagnetic coil;

3. The switching circuit according to claim 2, wherein the interlock control module comprises a rectifying module and a voltage stabilizing module;

4. The switching circuit of claim 3 wherein the rectifier module comprises a rectifier bridge and the voltage regulator module comprises a first capacitor;

5. The switching circuit of claim 1 wherein the solid state switching module comprises a first MOS transistor and a second MOS transistor;

6. The switching circuit of claim 5 wherein the solid state switching module further comprises a first resistor;

7. The switching circuit according to any one of claims 2 to 5, further comprising a current detection module configured to detect a line current level of a power supply line, and a voltage control module having an input connected to an output of the current detection module;

when the line current is smaller than a first preset value, the voltage control module provides a first preset voltage to the electromagnetic coil; when the line current is greater than or equal to a first preset value, the voltage control module provides a second preset voltage to the electromagnetic coil;

the second preset voltage is greater than the first preset voltage, so that the disconnection speed of the mechanical switch module is increased when the line current is greater than or equal to a first preset value.

8. The switching circuit according to claim 7, wherein the voltage control module comprises a short circuit judgment module and a voltage input module;

9. The switching circuit according to claim 8, wherein the voltage input module includes a first switch, and the short circuit determination module includes a first comparator;

one end of the first switch is connected with the second preset voltage, and the other end of the first switch is connected with the electromagnetic coil;

the non-inverting input end of the first comparator is connected with the output end of the current detection module, the inverting input end of the first comparator is connected with a first comparison voltage, and the output end of the first comparator is connected with the first switch.

10. The switching circuit according to claim 9, wherein the short circuit determination module further comprises a second comparator;

The inverting input end of the second comparator is connected with the output end of the current detection module, the non-inverting input end of the first comparator is connected with a second comparison voltage, and the output end of the second comparator is connected with the first switch control end.

11. The switching circuit of claim 8 wherein the voltage control module further comprises a signal holding module;

12. The switching circuit of claim 11 wherein said signal holding module comprises a first or gate;

13. The switching circuit of claim 7 wherein the electromagnetic coil comprises a first coil and a second coil;

when the line current is smaller than a first preset value, the voltage control module provides a first preset voltage to the first coil and the second coil; when the line current is greater than or equal to a first preset value, the voltage control module provides a second preset voltage to the first coil and the second coil.

14. The switching circuit of claim 13, wherein the switching circuit further comprises a first control switch and a second control switch;

a first end of the first control switch is connected with a second end of the first coil, and a second end of the first control switch is grounded; the first end of the second control switch is connected with the second end of the second coil, and the second end of the second control switch is grounded.

15. The switching circuit of claim 14 wherein a control terminal of the second control switch is connected to the voltage control module;

when the line current is greater than or equal to a first preset value, the voltage control module provides a second preset voltage for the second coil and controls the second control switch to be repeatedly opened and closed, so that the second coil is enabled to be electrified with pulse current.

16. A relay system comprising a switching circuit as claimed in any one of claims 1 to 15.