CN220933145U - Solid-state switching device and self-checking circuit thereof - Google Patents

Abstract

The utility model discloses a solid-state switching device and a self-checking circuit thereof, and relates to the technical field of switching devices. The solid-state switching device includes: a main loop switching unit and a solid state switching unit; the external power supply, the main loop switch unit, the solid-state switch unit and the load are sequentially connected in series; the self-checking circuit includes: the device comprises a detection power supply, a feedback module and a control module. The first end of the detection power supply is connected with the first end of the solid-state switch unit; the first connecting end of the feedback module is connected with the second end of the detection power supply, and the second connecting end of the feedback module is connected with the second end of the solid-state switch unit; the control module is respectively connected with the control end of the solid-state switch unit and the output end of the feedback module. The embodiment of the utility model can realize the detection of the health state of the solid-state switching device, and is beneficial to improving the operation reliability of the solid-state switching device.

Description

Solid-state switching device and self-checking circuit thereof

Technical Field

The utility model relates to the technical field of switching devices, in particular to a solid-state switching device and a self-checking circuit thereof.

Background

At present, the solid-state switching device is widely applied to a power system due to the advantage of long electric life and is used for controlling the connection or disconnection of an electric loop in the power system. The health state of the solid-state switching device is closely related to the operation of the power system, any abnormal or invalid switch in the solid-state switching device can influence the control effect on the electric loop, potential safety hazards are caused, and the action of the solid-state switching device under abnormal conditions can influence the electric life of the solid-state switching device. Therefore, in order to ensure reliable operation of the power system, it is necessary to detect the state of the solid-state switching device. However, the prior art lacks a self-checking scheme for the health state of the solid-state switching device, and the operation reliability of the solid-state switching device is lower.

Disclosure of utility model

The utility model provides a solid-state switching device and a self-checking circuit thereof, which can realize the detection of the health state of the solid-state switching device and are beneficial to improving the operation reliability of the solid-state switching device.

In a first aspect, an embodiment of the present utility model provides a self-checking circuit of a solid-state switching device, the solid-state switching device including: a main loop switching unit and a solid state switching unit; the first end of the main loop switch unit is connected with the first end of an external power supply, the second end of the main loop switch unit is connected with the first end of the solid-state switch unit, the second end of the solid-state switch unit is connected with the first end of a load, and the second end of the load is connected with the second end of the external power supply;

the self-checking circuit includes:

the first end of the detection power supply is connected with the first end of the solid-state switch unit;

The first connecting end of the feedback module is connected with the second end of the detection power supply, and the second connecting end of the feedback module is connected with the second end of the solid-state switch unit;

The control module is respectively connected with the control end of the solid-state switch unit and the output end of the feedback module; the control module is used for controlling the switching state of the solid-state switching unit and judging the health states of the main loop switching unit and the solid-state switching unit according to the feedback signal output by the feedback module.

Optionally, the feedback module comprises a photo coupler;

The first end of the emitting part of the photoelectric coupler is connected with the second end of the detection power supply, the second end of the emitting part of the photoelectric coupler is connected with the second end of the solid-state switch unit, and the receiving part of the photoelectric coupler is connected with the control module.

Optionally, the control module is further connected to a control end of the main loop switch unit to control a switching state of the main loop switch unit.

Optionally, the self-checking circuit further comprises: an anti-reverse module comprising: a diode; the first pole of the diode is connected with the second connecting end of the feedback module, and the second pole of the diode is connected with the second end of the solid-state switch unit.

Optionally, the first end of the detection power supply is an anode of the detection power supply, and the second end of the detection power supply is a cathode of the detection power supply; the first pole of the diode is the cathode of the diode, and the second pole of the diode is the anode of the diode;

Or the first end of the detection power supply is the negative electrode of the detection power supply, and the second end of the detection power supply is the positive electrode of the detection power supply; the first pole of the diode is the anode of the diode, and the second pole of the diode is the cathode of the diode.

Optionally, the control module includes:

the control unit is respectively connected with the control end of the main loop switch unit and the output end of the feedback module;

And the driving unit is respectively connected with the control end of the solid-state switch unit and the control unit.

Optionally, the self-checking circuit further comprises:

The current limiting module comprises a current limiting resistor which is connected between the second end of the detection power supply and the first connecting end of the feedback module;

And the detection switch is connected between the first end of the detection power supply and the first end of the solid-state switch unit or between the second end of the detection power supply and the second end of the solid-state switch unit.

In a second aspect, an embodiment of the present utility model further provides a solid-state switching device, including: the self-checking circuit comprises a main loop switch unit, a solid-state switch unit and the solid-state switch electric appliance provided by any embodiment of the utility model.

Optionally, the solid-state switching device is a pure solid-state switching device, and the solid-state switching unit includes: and the control end of the power electronic device is connected with the control module.

Optionally, the solid-state switching device is a hybrid solid-state switching device, and the solid-state switching unit includes:

A power electronics branch comprising: two power electronics connected in series between the first and second ends of the solid state switching unit, a control end of the power electronics being connected to the control module;

And a mechanical switch connected in parallel with the power electronic branch.

The self-checking circuit of the solid-state switching device is provided with a detection power supply, a feedback module and a control module. By controlling the switching states of the main loop switching unit and the solid state switching unit, different detection loops can be formed, and the control module can detect the health state of the switching units in each detection loop. Meanwhile, through the arrangement of the connection relation of the functional modules, each detection loop comprises a detection power supply and a feedback module, so that a plurality of detection power supplies and feedback modules do not need to be arranged for different switch units, and the self-checking circuit is simple in structure and easy to realize. Therefore, compared with the prior art, the utility model can realize the detection of the health state of the solid-state switching device and is beneficial to improving the operation reliability of the solid-state switching device.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the utility model or to delineate the scope of the utility model. Other features of the present utility model will become apparent from the description that follows.

Drawings

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

Fig. 1 is a schematic structural diagram of a solid-state switching device according to an embodiment of the present utility model;

Fig. 2 is a schematic structural diagram of another solid-state switching device according to an embodiment of the present utility model;

Fig. 3 is a schematic structural diagram of still another solid-state switching device according to an embodiment of the present utility model.

Detailed Description

In order that those skilled in the art will better understand the present utility model, a technical solution in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, shall fall within the scope of the present utility model.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present utility model and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.

The embodiment of the utility model provides a self-checking circuit of a solid-state switching device, which can realize the self-checking of the health state of the solid-state switching device. Fig. 1 is a schematic structural diagram of a solid-state switching device according to an embodiment of the present utility model. Referring to fig. 1, the solid-state switching device 100 includes: a main loop switch unit 10, a solid state switch unit 20 and a self-test circuit 30. The external power source ES, the main circuit switching unit 10, the solid-state switching unit 20 and the load LS are connected in series to form a power supply circuit of the external power source ES to the load LS, and when both the main circuit switching unit 10 and the solid-state switching unit 20 are turned on, the external power source ES can supply power to the load LS. The solid-state switching device 100 may be provided in a power system, the external power source ES may be any power source in the system, and the load LS may be any load in the system corresponding to the external power source ES. The self-checking circuit 30 can detect the health status of each switching device in the main loop switching unit 10 and the solid-state switching unit 20 before and/or during the operation of the solid-state switching device 100, and can determine that the solid-state switching device 100 is healthy and control the solid-state switching device 100 to operate normally when no abnormality exists in each switching device, and can determine that the solid-state switching device 100 is abnormal and generate an alarm signal when any switching device is abnormal, so as to avoid the solid-state switching device 100 from operating under abnormal conditions and avoid reducing the electrical life of the solid-state switching device 100 as much as possible. The health status of the switching device is, for example, whether the switching device can be turned on or off, whether the operation time meets the requirements, and the like.

Specifically, the first terminal 11 of the main circuit switch unit 10 is connected to a first terminal (e.g., positive electrode) of the external power source ES, the second terminal 12 of the main circuit switch unit 10 is connected to a first terminal 21 of the solid-state switch unit 20, the second terminal 22 of the solid-state switch unit 20 is connected to a first terminal of the load LS, and the second terminal of the load LS is connected to a second terminal (e.g., negative electrode) of the external power source ES.

The self-test circuit 30 includes: the detection power supply 310, the feedback module 320, and the control module 330. The first terminal 31 of the detection power supply 310 is connected to the first terminal 21 of the solid-state switching unit 20; the detection power supply 310 is, for example, an isolated power supply. The first connection terminal 41 of the feedback module 320 is connected to the second terminal 32 of the detection power supply 310, and the second connection terminal 42 of the feedback module 320 is connected to the second terminal 22 of the solid-state switching unit 20; the feedback module 320 may output a feedback signal indicative of loop conduction when loop current is detected to flow between the second terminal 32 of the power supply 310 and the second terminal 22 of the solid state switching unit 20. The control module 330 is connected to the control terminal 23 of the solid-state switching unit 20 and the output terminal 43 of the feedback module 320, respectively. The control module 330 is configured to control the switching states of the solid-state switching unit 20, and determine the health states of the main loop switching unit 10 and the solid-state switching unit 20 according to the feedback signal output by the feedback module 320. The main circuit switch unit 10 may be manually controlled to switch on/off, however, for convenience in detection, the control module 330 may be connected to a control terminal of the main circuit switch unit 10, and the control module 330 may control the switch on/off of the main circuit switch unit 10.

For example, for any one of the main loop switch unit 10 and the solid state switch unit 20, at least one switch branch disposed between the first end and the second end of the switch unit may be included, and the control module 330 may perform health status detection for each switch branch, and may determine that the switch unit is healthy when all switch branches in the same switch unit are healthy.

Specifically, the principle of the control module 330 detecting the health status of the switching branches in the main loop switching unit 10 and the solid state switching unit 20 may be:

the control module 330 controls any one of the switching branches of the main loop switching unit 10 to be turned on, and controls all the switching branches of the solid-state switching unit 20 to be turned off, and the feedback module 320 is located in a detection loop formed by the detection power supply 310, the feedback module 320, the load LS, the external power supply ES and the main loop switching unit 10. In this case, if the switching leg is capable of conducting, there is a current flow in the loop; at this time, the feedback module 320 receives the loop current and outputs a feedback signal indicating the loop conduction to the control module 330. The control module 330 may diagnose the health status of the switching leg by the status and the time of action of the switching leg. For example, the control module 330, upon receiving a feedback signal indicative of loop conduction, may confirm that conduction has occurred between the first terminal 11 and the second terminal 12 of the main loop switch unit 10, thereby confirming that the switch leg has been conducted; on this basis, the control module 330 may record the time difference between sending the on control signal to the switching leg and receiving the feedback signal as the operation time of the switching leg, and if the operation time is within the normal operation time range of the switching leg, the control module 330 may determine that the switching leg is healthy.

The control module 330 controls all switching branches in the main loop switching unit 10 to be turned off, and controls any switching branch in the solid-state switching unit 20 to be turned on, and the feedback module 320 is located in a detection loop formed by the detection power supply 310, the feedback module 320 and the solid-state switching unit 20. In this case, if the switching leg is capable of conducting, there is a current flow in the loop; at this time, the feedback module 320 receives the loop current and outputs a feedback signal indicating the loop conduction to the control module 330. The control module 330 may diagnose the health status of the switching leg by the status and the time of action of the switching leg. For example, the control module 330 may confirm that the switching leg is turned on upon receiving a feedback signal indicative of loop conduction; on this basis, the control module 330 may record the time difference between sending the on control signal to the switching leg and receiving the feedback signal as the operation time of the switching leg, and if the operation time is within the normal operation time range of the switching leg, the control module 330 may determine that the switching leg is healthy.

In summary, in the self-checking circuit 30 of the solid-state switching device 100 provided by the embodiment of the utility model, the detection power supply 310, the feedback module 320 and the control module 330 are provided. By controlling the switching states of the main loop switching unit 10 and the solid state switching unit 20, different detection loops may be formed, and the control module 330 may detect the health state of the switching units in each detection loop. Meanwhile, by setting the connection relation of the functional modules, each detection circuit comprises the detection power supply 310 and the feedback module 320, so that a plurality of detection power supplies 310 and feedback modules 320 are not required to be arranged for different switch units, and the self-detection circuit 30 is simple in structure and easy to realize. Therefore, compared with the prior art, the embodiment of the utility model can realize the detection of the health state of the solid-state switching device 100, and is beneficial to improving the operation reliability of the solid-state switching device 100.

Fig. 2 is a schematic structural diagram of another solid-state switching device according to an embodiment of the present utility model. Referring to fig. 2, the feedback module 320 may optionally include a photo coupler U1 on the basis of the above embodiments. The first end of the emitting part of the photo coupler U1 is connected to the second end 32 of the detection power supply 310, the second end of the emitting part of the photo coupler U1 is connected to the second end 22 of the solid-state switch unit 20, and the receiving part of the photo coupler U1 is connected to the control module 330. Illustratively, different endpoints of the receiving portion of the photo coupler U1 may be connected to different nodes in the control module 330, for example, a first end of the receiving portion of the photo coupler U1 is connected to a first signal end of the control module 330, and a first end of the receiving portion of the photo coupler U1 is connected to a first power end (e.g., a ground end) of the control module 330. Then, when the detection circuit where the transmitting portion of the photo coupler U1 is located is turned on, the transmitting portion emits light to control the receiving portion of the photo coupler U1 to be turned on, so that the first signal end of the control module 330 receives the signal of the first power end, and at this time, the control module 330 can confirm that the detection circuit is turned on. In this embodiment, the photocoupler U1 is provided as a feedback module, so that electrical isolation between the detection loop and the control loop can be achieved, and the safety of the self-checking circuit 30 is improved.

With continued reference to fig. 2, the self-checking circuit 30 may further include: the current limiting module 340 is connected between the second end 32 of the detection power supply 310 and the first connection end of the feedback module 320, and is used for limiting the size of the loop circuit in the detection loop, and improving the safety of the self-checking circuit 30. Illustratively, the current limiting module 340 may include a current limiting resistor R coupled between the second terminal 32 of the detection power source 310 and the first connection terminal of the feedback module 320.

With continued reference to fig. 2, the self-checking circuit 30 may further include: the anti-reverse connection module 350 is connected between the second connection terminal of the feedback module 320 and the second terminal 22 of the solid-state switching unit 20. Illustratively, a diode D may be included in the anti-reverse module 350; the first pole of diode D is connected to the second connection of feedback module 320 and the second pole of diode D is connected to the second terminal 22 of solid state switching unit 20.

In addition to the above embodiments, the diode D may be optionally disposed in a manner related to the polarity of the detection power source 310, where the diode D is used to enable the electrical signal of the detection power source 310 to flow through the detection circuit.

Specifically, referring to fig. 2, when the first terminal 31 of the detection power supply 310 is the positive electrode of the detection power supply 310 and the second terminal 32 of the detection power supply 310 is the negative electrode of the detection power supply 310, the first electrode of the diode D may be set as the cathode of the diode D and the second electrode of the diode D may be set as the anode of the diode D. Alternatively, as shown in fig. 3, when the first end 31 of the detection power supply 310 is the negative electrode of the detection power supply 310 and the second end 32 of the detection power supply 310 is the positive electrode of the detection power supply 310, the first electrode of the diode D may be set as the anode of the diode D and the second electrode of the diode D may be set as the cathode of the diode D. Accordingly, the anode of the diode D is connected with the anode of the detection power supply 310, the cathode of the diode D is connected with the cathode of the detection power supply 310, and the normal circulation of current in the detection loop is ensured.

With continued reference to fig. 2 and 3, the control module 330 may optionally include, based on the foregoing embodiments: a control unit 331 and a driving unit 332. Wherein, the control unit 331 is respectively connected with the control end of the main loop switch unit 10 and the output end of the feedback module 320; the driving unit 332 is connected to the control terminal of the solid-state switching unit 20 and the control unit 331, respectively. The control unit 331 may directly control the switching states of the switching branches in the main loop switching unit 10, and control the switching states of the switching branches in the solid state switching unit 20 through the driving unit 332. Alternatively, the control unit 331 may be connected to a part of the switch branches in the solid-state switch unit 20, and implement direct control of the switch branches, and the specific control manner is not limited herein.

With continued reference to fig. 3, the self-checking circuit 30 may further include: the detection switch S3 is connected between the first terminal 31 of the detection power supply 310 and the first terminal 21 of the solid-state switch unit 20. The control end of the detection switch S3 may be connected to the control module 330, and the control module 330 controls the on-off state of the detection switch S3. The control module 330 can control whether the self-checking process is performed by controlling the on-off state of the detection switch S3, so as to improve the flexibility of detection control. The setting position of the detection switch S3 in fig. 3 is not a limitation of the present utility model. In other embodiments, the detection switch S3 may alternatively be connected to any position between the second terminal 32 of the detection power supply 310 and the second terminal 22 of the solid-state switch unit 20, as long as the overall on-off control of each detection circuit can be achieved.

Alternatively, the self-checking circuit 30 may be applied to any structure of the solid-state switching device 100, such as a solid-state switching device or a hybrid solid-state switching device, as described below.

Referring to fig. 2, in one embodiment, the solid-state switching device 100 is optionally a pure solid-state switching device. The main loop switch unit 10 includes a main loop switch S1 connected between a first end and a second end of the main loop switch unit 10; the solid-state switching unit 20 includes: a power electronic device Q connected between the first end 21 and the second end 22 of the solid-state switching unit 20; the first end 2 of the power electronic device Q is connected with the first end 21 of the solid-state switch unit 20, the second end 3 of the power electronic device Q is connected with the second end 22 of the solid-state switch unit 20, and the control end of the main loop switch S1 and the control end 1 of the power electronic device Q are both connected with the control module 330; the control module 330 may also be connected to the second terminal 3 of the power electronic device Q. By way of example, the power electronics Q may be a semiconductor device such as a Metal-Oxide-semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) or a thyristor (Silicon Controlled Rectifier, SCR).

Specifically, for a pure solid-state switching device, the health state detection process is as follows:

Detecting the health state of the main loop switch S1: the control unit 331 controls the main loop switch S1 to be closed and controls the power electronic device Q to be turned off, and the positive current of the detection power supply 310 flows to the negative electrode of the detection power supply 310 through the main loop switch S1, the external power supply ES (the external power supply ES may be regarded as a low impedance element in the loop), the load LS, the diode D, the emitter of the photo coupler U1, and the current limiting resistor R to form a detection loop. At this time, if the main loop switch S1 can be normally closed, the photo coupler U1 can transmit a feedback signal to the control unit 331 for judgment. The control unit 331 can diagnose the health condition through the state and the action time of the main loop switch S1.

Detecting the health state of the power electronic device Q: the control unit 331 controls the main loop switch S1 to be turned off and controls the power electronic device Q to be turned on, and the current of the positive electrode of the detection power supply 310 flows to the negative electrode of the detection power supply 310 through the power electronic device Q, the diode D, the emitting part of the photo coupler U1 and the current limiting resistor R to form a detection loop. At this time, if the power electronic device Q can be normally turned on, the photo coupler U1 can transmit a feedback signal to the control unit 331 for determining. The control unit 331 can diagnose the health condition of the power electronic device Q by the state and the action time thereof.

Fig. 3 is a schematic structural diagram of still another solid-state switching device according to an embodiment of the present utility model. Referring to fig. 3, in one embodiment, the solid-state switching device 100 is optionally a hybrid solid-state switching device. The main loop switch unit 10 includes a main loop switch S1 connected between a first end and a second end of the main loop switch unit 10. The solid-state switching unit 20 includes: a power electronics branch comprising: two power electronic devices Q connected in series between the first end 21 and the second end 22 of the solid-state switching unit 20, the control terminal 1 of each power electronic device Q being connected to the control module 330. And, the solid-state switching unit 20 further includes: and a mechanical switch S2 connected in parallel with the power electronic branch. The mechanical switch S2 may be controlled by a manual control of the switch state, or a control end of the mechanical switch S2 may also be connected to the control module 330, and the switch state of the mechanical switch S2 is controlled by the control module 330.

Here, for convenience of distinction, the power electronics connected to the first end 21 of the solid-state switching unit 20 are denoted as first power electronics Q1, and the power electronics connected to the second end 22 of the solid-state switching unit 20 are denoted as second power electronics Q2. For example, a first terminal 2 of a first power electronic device Q1 may be provided connected to a first terminal 21 of the solid state switching unit 20, a second terminal 3 of the first power electronic device Q1 is connected to a second terminal 3 of a second power electronic device Q2, and a first terminal 2 of the second power electronic device Q2 is connected to a second terminal 22 of the solid state switching unit 20. And, for ease of control, the drive unit 332 may also be connected to the second ends 3 of the two power electronics Q. The arrangement is such that the mechanical switch S2 constitutes a first switching leg in the solid-state switching unit 20 and the power electronic leg constitutes a second switching leg in the solid-state switching unit 20, the control module 330 being able to detect the health status of the different switching legs, respectively.

Specifically, during the detection process, the control module 330 may control the detection switch S3 to remain closed, and the detection switch S3 may be considered a current path. Then, for the hybrid solid-state switching device, the health status detection process is as follows:

Detecting the health state of the main loop switch S1: the control unit 331 controls the main loop switch S1 to be closed, controls the mechanical switch S2 to be opened, controls the two power electronic devices Q to be turned off, and controls the current of the positive electrode of the detection power supply 310 to flow to the negative electrode of the detection power supply 310 through the current limiting resistor R, the emitting part of the photoelectric coupler U1, the diode D, the load LS, the external power supply ES and the main loop switch S1 to form a detection loop. At this time, if the main loop switch S1 can be normally closed, the photo coupler U1 can transmit a feedback signal to the control unit 331 for judgment. The control unit 331 can diagnose the health condition through the state and the action time of the main loop switch S1.

Detecting the health state of a first switch branch: the control unit 331 controls the main loop switch S1 to be opened, controls the mechanical switch S2 to be closed, and controls the two power electronic devices Q to be turned off, and the current of the positive electrode of the detection power supply 310 flows to the negative electrode of the detection power supply 310 through the current limiting resistor R, the transmitting part of the photoelectric coupler U1, the diode D and the mechanical switch S2 to form a detection loop. At this time, if the mechanical switch S2 can be normally closed, the photo coupler U1 can transmit a feedback signal to the control unit 331 for determining. The control unit 331 can diagnose the health condition through the state and the action time of the mechanical switch S2.

Detecting the health state of the second switch branch: the control unit 331 controls the main loop switch S1 to be turned off, controls the mechanical switch S2 to be turned off, and controls the two power electronic devices Q to be turned on, and the current of the positive electrode of the detection power supply 310 flows to the negative electrode of the detection power supply 310 through the current limiting resistor R, the emitting part of the photo coupler U1, the diode D, the second power electronic device Q2 and the first power electronic device Q1 to form a detection loop. At this time, if both the two power electronic devices Q can be normally closed, the photo coupler U1 may transmit a feedback signal to the control unit 331 for determining. The control unit 331 can diagnose the health condition of the two power electronic devices Q by the states and the action time.

In summary, in the self-checking circuit 30 provided by the embodiment of the present utility model, the detection power supply 310, the isolation resistor R, the photo coupler U1 and the diode D are sequentially connected in series to form a detection circuit, one end of the detection circuit is connected to the first end 21 of the solid-state switch unit 20, and the other end is connected to the second end 22 of the solid-state switch unit 20, and this connection manner can ensure the air break point of the solid-state switch device 100. The control module 330 controls the switching states of the switching devices, so that the detection circuits can be arranged in different detection loops, the state self-detection of the switching devices is realized, the abnormality of the switching devices such as the main loop switch S1 and the power electronic device Q can be timely reminded, and the operation reliability of the solid-state switching device 100 is improved.

The embodiment of the utility model also provides a solid-state switching device, which comprises the self-checking circuit provided by any embodiment of the utility model and has corresponding beneficial effects. Illustratively, the solid-state switching device comprises a main loop switching unit, a solid-state switching unit and a self-checking circuit; the self-checking circuit is used for detecting the health state of each switching device in the main loop switching unit and the solid-state switching unit. And the control module in the self-checking circuit is also used for controlling the running states of all the switching devices in the main loop switching unit and the solid-state switching unit in the running process of the system. Or, the original control device in the solid-state switching device can be reused as the control module in the self-checking circuit, and the control module does not need to be arranged for the self-checking circuit separately, so that the device structure is simplified and the cost is reduced. The solid-state switching device may be a solid-state circuit breaker, a solid-state contactor, or a solid-state relay, and the specific type of the solid-state switching device and the specific type of the internal switching device may be selected according to actual requirements, which are not limited herein.

Alternatively, the solid-state switching device may be a pure solid-state switching device or a hybrid solid-state switching device based on the above embodiments. It should be noted that, in each embodiment of the self-checking circuit, the structures of different solid-state switching devices are specifically described, and technical details that are not explained in detail in this embodiment can be seen in the description of each embodiment of the self-checking circuit, and the details are not repeated here.

The above embodiments do not limit the scope of the present utility model. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included in the scope of the present utility model.

Claims (10)

1. A self-test circuit of a solid state switching device, the solid state switching device comprising: a main loop switching unit and a solid state switching unit; the first end of the main loop switch unit is connected with the first end of an external power supply, the second end of the main loop switch unit is connected with the first end of the solid-state switch unit, the second end of the solid-state switch unit is connected with the first end of a load, and the second end of the load is connected with the second end of the external power supply;

the self-checking circuit includes:

the first end of the detection power supply is connected with the first end of the solid-state switch unit;

The first connecting end of the feedback module is connected with the second end of the detection power supply, and the second connecting end of the feedback module is connected with the second end of the solid-state switch unit;

The control module is respectively connected with the control end of the solid-state switch unit and the output end of the feedback module; the control module is used for controlling the switching state of the solid-state switching unit and judging the health states of the main loop switching unit and the solid-state switching unit according to the feedback signal output by the feedback module.

2. The self-test circuit of a solid state switching device according to claim 1, wherein the feedback module comprises a photo coupler;

The first end of the emitting part of the photoelectric coupler is connected with the second end of the detection power supply, the second end of the emitting part of the photoelectric coupler is connected with the second end of the solid-state switch unit, and the receiving part of the photoelectric coupler is connected with the control module.

3. The self-test circuit of a solid state switching device according to claim 1, wherein the control module is further connected to a control terminal of the main loop switching unit to control a switching state of the main loop switching unit.

4. The self-test circuit of a solid state switching device according to claim 1, further comprising: an anti-reverse module comprising: a diode; the first pole of the diode is connected with the second connecting end of the feedback module, and the second pole of the diode is connected with the second end of the solid-state switch unit.

5. The self-test circuit of a solid state switching device according to claim 4, wherein a first end of the detection power supply is an anode of the detection power supply, and a second end of the detection power supply is a cathode of the detection power supply; the first pole of the diode is the cathode of the diode, and the second pole of the diode is the anode of the diode;

Or the first end of the detection power supply is the negative electrode of the detection power supply, and the second end of the detection power supply is the positive electrode of the detection power supply; the first pole of the diode is the anode of the diode, and the second pole of the diode is the cathode of the diode.

6. The self-test circuit of a solid state switching device according to claim 1, wherein the control module comprises:

the control unit is respectively connected with the control end of the main loop switch unit and the output end of the feedback module;

And the driving unit is respectively connected with the control end of the solid-state switch unit and the control unit.

7. The self-test circuit of a solid state switching device according to any one of claims 1 to 6, further comprising:

The current limiting module comprises a current limiting resistor which is connected between the second end of the detection power supply and the first connecting end of the feedback module;

And the detection switch is connected between the first end of the detection power supply and the first end of the solid-state switch unit or between the second end of the detection power supply and the second end of the solid-state switch unit.

8. A solid state switching device, comprising: a main loop switching unit, a solid state switching unit and a self-test circuit of a solid state switching device as claimed in any one of claims 1 to 7.

9. The solid state switching device according to claim 8, wherein the solid state switching device is a pure solid state switching device, the solid state switching unit comprising: and the control end of the power electronic device is connected with the control module.

10. The solid state switching device of claim 8, wherein the solid state switching device is a hybrid solid state switching device, the solid state switching unit comprising:

A power electronics branch comprising: two power electronics connected in series between the first and second ends of the solid state switching unit, a control end of the power electronics being connected to the control module;

And a mechanical switch connected in parallel with the power electronic branch.