A non-voltage drop type bus short-circuit isolation system and a bus device short-circuit protection method

Abstract

The present invention discloses a bus short-circuit isolation system without voltage drop and a bus device short-circuit protection method. The system includes a protection control circuit, a recovery control circuit, a first switch, a second switch and a resettable fuse; the first switch and the resettable fuse are connected in series on the first bus, and together as a short-circuit isolation component, they are connected between the bus end and the device end; the protection control circuit is connected in parallel with the short-circuit isolation component; the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end, and is connected to the first bus through the second switch; the protection control circuit is used to control the relay action through the relay coil when power is turned on; the recovery control circuit is used to output a relay control signal to the protection control circuit when power is turned on; the first switch is the normally closed end of the relay, and the second switch is the normally open end of the relay. By adopting the above technical solution, when a short circuit occurs at the device end, circuit breaker protection can be performed, and normal power supply and communication at the device end can be automatically restored when the fault is removed.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit protection, and in particular to a voltage drop-free bus short-circuit isolation system and a bus device short-circuit protection method. Background Art

[0002] Bus communication is a way of exchanging data, addresses and control information between components in a hardware system. The bus is the physical channel connecting the components, and bus communication is the information exchange process on this channel. Bus communication has the characteristics of multiple devices sharing the same communication line, and any device can send or receive information on the bus. Since there are many devices on the bus and the working conditions of each device are different, faults may occur in many cases. The short circuit of the faulty device will cause the entire bus communication to be paralyzed, bringing unpredictable losses.

[0003] In order to solve the problem of bus communication paralysis caused by device short circuit, the fault point can be isolated by a bus short circuit isolator to avoid the impact of the fault point on other devices on the bus. The short circuit isolation currently used in the market generally connects the sampling resistor in series in the bus, but the sampling resistor has a certain resistance value, which may cause the bus voltage drop to decrease. In addition, after the signal is collected, a controller is required for logical control, which increases the complexity of the system. Summary of the invention

[0004] The present invention provides a bus short-circuit isolation system without voltage drop and a bus device short-circuit protection method, which can provide circuit-breaking protection for the device end when a short circuit occurs at the device end, and automatically restore normal power supply and communication at the device end when the fault is removed.

[0005] According to one aspect of the present invention, there is provided a bus short-circuit isolation system without voltage drop, which is configured in a two-bus system, wherein each device end in the two-bus system is respectively connected in parallel between a first bus and a second bus at a bus end, and the isolation system comprises a protection control circuit, a recovery control circuit, a first switch, a second switch and a self-recovery fuse;

[0006] The first switch and the resettable fuse are connected in series on the first bus, and are connected between the bus end and the device end as a short-circuit isolation component; the protection control circuit is connected in parallel with the short-circuit isolation component; the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end, and is connected to the first bus through the second switch;

[0007] The protection control circuit is used to control the action of the relay through the relay coil when power is on; the recovery control circuit is used to output a relay control signal to the protection control circuit when power is on, so as to control the action of the relay through the relay coil in the protection control circuit;

[0008] The first switch is the normally closed end of the relay, and the second switch is the normally open end of the relay; when the relay in the protection controller circuit is actuated, the opening and closing states of the first switch and the second switch change.

[0009] Optionally, the first connection end of the second switch is connected between the protection control circuit and the device end on the first bus, the second connection end of the second switch is connected to the first connection end of the recovery control circuit, and the second connection end of the recovery control circuit is connected between the bus end and the device end of the second bus.

[0010] Optionally, the protection control circuit is specifically used to implement the following functions:

[0011] When the power is not supplied, the first switch is controlled to be in a closed state, and the second switch is controlled to be in an open state;

[0012] When switching from the non-powered state to the powered state, controlling the first switch to switch from the closed state to the open state, and controlling the second switch to switch from the open state to the closed state; and

[0013] When a relay control signal is received in the power-on state, the first switch is controlled to switch from the open state to the closed state, and the second switch is controlled to switch from the closed state to the open state.

[0014] Optionally, the protection control circuit includes a first rectifier bridge and a relay coil;

[0015] The input end of the first rectifier bridge is connected to the first bus, and the output end of the first rectifier bridge is connected in parallel with the relay coil.

[0016] Optionally, the protection control circuit also includes a light emitting diode, and the light emitting diode is connected in parallel with the relay coil.

[0017] Optionally, the recovery control circuit includes a second rectifier bridge and a photoelectric coupler:

[0018] The input end of the second rectifier bridge is respectively connected to the first bus and the second bus, and the output end of the second rectifier bridge is respectively connected to the input end of the photoelectric coupler;

[0019] The photoelectric coupler outputs a relay control signal to the relay coil in the protection control circuit when powered on.

[0020] According to another aspect of the present invention, a bus device short-circuit protection method is provided, which is applied to the non-voltage drop type bus short-circuit isolation system as described in any embodiment of the present invention, comprising:

[0021] When all the equipment ends in the two-bus system are in normal working state, the protection control circuit is controlled by the short-circuit isolation component to remain in an unpowered state, and the connection between the recovery control circuit and the bus end is disconnected by the second switch in the open state.

[0022] Optionally, the method further includes:

[0023] When a device in the two-bus system is short-circuited, the power supply from the first bus to each device end is disconnected through a self-recovery fuse, and the protection control circuit is switched from a non-powered state to a powered state by disconnecting the short-circuit isolation component;

[0024] By protecting the control circuit, when switching from an unpowered state to a powered state, the first switch is switched from a closed state to an open state, and the second switch is switched from an open state to a closed state, so that the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end in a connected manner, and when the self-recovery fuse is restored to connectivity, the power supply connection between the first bus and each device end is still disconnected.

[0025] Optionally, the method further includes:

[0026] When the device end that has a short circuit in the two-bus system recovers from the short circuit state to the normal working state, the recovery control circuit switches from the non-powered state to the powered state;

[0027] By restoring the control circuit, when switching from the non-powered state to the powered state, a relay control signal is output to the relay coil in the protection control circuit.

[0028] Optionally, after outputting the relay control signal to the relay coil in the protection control circuit, the method further includes:

[0029] Through the protection control circuit, when a relay control signal is received in the power-on state, the first switch is controlled to switch from the open state to the closed state, and the second switch is controlled to switch from the closed state to the open state, so that the short-circuit isolation component is connected in series on the first bus in a connected manner, and the normal power supply of the first bus is restored. When the short-circuit isolation component is connected, the protection control circuit is connected in parallel with the short-circuit isolation component in a short-circuit state, and the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end in an open-circuit state.

[0030] The technical solution of the embodiment of the present invention configures a protection control circuit, a recovery control circuit, a first switch, a second switch and a resettable fuse in a voltage-drop-free bus short-circuit isolation system. The first switch and the resettable fuse are connected in series on the first bus and are connected between the bus end and the device end as a short-circuit isolation component. The protection control circuit is connected in parallel with the short-circuit isolation component. The recovery control circuit is connected in parallel between the first bus and the second bus at the bus end and is connected to the first bus through the second switch. The first switch is set as the normally closed end of the relay, and the second switch is set as the normally open end of the relay. Short-circuit protection of the two-bus system can be achieved through the physical characteristics of each electronic device. The series connection of the switch and the resettable fuse in the bus avoids the problems of reduced bus voltage drop and bus current consumption, and ensures the load capacity of the bus. In addition, short-circuit protection based on physical characteristics does not require logical control, reduces the complexity of the two-bus system, reduces costs, improves output efficiency, and is stable and reliable. At the same time, it also has the function of fault indication alarm. When the fault is removed, the two-bus system can also restore the normal working state in time to ensure normal power supply and communication.

[0031] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 2 is a schematic structural diagram of a bus short-circuit isolation system without voltage drop provided according to Embodiment 1 of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of a sampling resistor in a conventional short-circuit isolator in a two-bus system according to an embodiment of the present invention;

[0035] Figure 3 2 is a schematic structural diagram of another non-voltage drop type bus short circuit isolation system provided according to an embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of a two-bus system structure at the time of a device-side short circuit provided by an embodiment of the present invention;

[0037] Figure 5 is a structural schematic diagram of a protection control circuit provided according to an embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of a two-bus system structure at a device-side recovery time provided in an embodiment of the present invention;

[0039] Figure 7 is a structural schematic diagram of a recovery control circuit provided according to an embodiment of the present invention;

[0040] Figure 8 This is a flow chart of a bus device short-circuit protection method provided according to Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0042] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0043] Embodiment 1

[0044] Figure 1 A schematic diagram of a bus short-circuit isolation system without voltage drop provided in the first embodiment of the present invention is shown in FIG. Figure 1 As shown, the bus short-circuit isolation system with no voltage drop is configured in a two-bus system, and each device end in the two-bus system is respectively connected in parallel between the first bus and the second bus at the bus end. The bus short-circuit isolation system with no voltage drop includes a protection control circuit 110, a recovery control circuit 120, a first switch 130, a second switch 140 and a self-recovery fuse 150.

[0045] Figure 2 FIG. 1 is a schematic diagram of an optional structure of a sampling resistor in an existing short-circuit isolator in a two-bus system. Figure 2 As shown, the existing short-circuit isolator connects the sampling resistor in series on one bus in the two-bus system, and determines whether the bus is short-circuited or overcurrent by obtaining the voltage across the sampling resistor. If a short circuit occurs, the device in the two-bus system can be cut off by the back-end controller. However, the sampling resistor has a certain resistance value, which may cause the problem of reduced bus voltage drop and reduce the bus load capacity. At the same time, in order to collect and monitor the voltage, it may be necessary to draw power from the bus, which will further consume the bus current. In addition, the back-end controller needs to judge the analog signal of the sampling resistor, and the logical processing of the signal will increase the complexity of the short-circuit isolator, resulting in low-efficiency output at a high cost.

[0046] It can be understood that in order to solve the above-mentioned problems of the existing short-circuit isolators, the first switch 130 and the resettable fuse 150 are connected in series on the first bus in the present invention. The first switch 130 and the resettable fuse 150 are similar to wires and will not share the voltage on the first bus, which can effectively ensure the load capacity of the bus. When the two-bus system is working normally, the first switch 130 and the resettable fuse 150 are turned on, and then the protection control circuit 110 is connected to the first bus in a short-circuit form, and the protection control circuit 110 is not powered, and the second switch 140 is in the disconnected state, and the recovery control circuit 120 is connected to the two-bus system in an open circuit form. At this time, the protection control circuit 110 and the recovery control circuit 120 will not consume the current of the two-bus system, nor will it cause the bus voltage drop to decrease.

[0047] Optionally, in a dual-bus system, the bus end includes a first bus and a second bus, both of which can transmit signals and provide power to the device end, the device end includes multiple devices, and each device is connected in parallel between the first bus and the second bus.

[0048] Optionally, the first switch 130 and the resettable fuse 150 are connected in series on the first bus, and together serve as a short-circuit isolation component connected between the bus end and the device end; the protection control circuit 110 is connected in parallel with the short-circuit isolation component; the recovery control circuit 120 is connected in parallel between the first bus and the second bus at the bus end, and is connected to the first bus through the second switch 140.

[0049] Optionally, the protection control circuit 110 is used to control the relay action through the relay coil when power is turned on; the recovery control circuit 120 is used to output a relay control signal to the protection control circuit 110 when power is turned on, so as to control the relay action through the relay coil in the protection control circuit 110.

[0050] Optionally, the first switch 130 is a normally closed end of the relay, and the second switch 140 is a normally open end of the relay; when the relay in the protection controller circuit is actuated, the opening and closing states of the first switch 130 and the second switch 140 change.

[0051] Figure 3 FIG. 1 is a schematic diagram of another optional bus short-circuit isolation system without voltage drop. Figure 3 As shown, S1 is the first switch 130, S2 is the second switch 140, "bus+" is the first bus, and "bus-" is the second bus. Here, the positive and negative signs are used to distinguish the first bus and the second bus. However, in an actual two-bus system, the first bus and the second bus are not polarized, and the polarities of the two buses may be swapped. Devices 1 to n are connected in parallel between the first bus and the second bus. Figure 3 As shown, S1 is a normally closed switch, and S2 is a normally open switch. Both S1 and S2 are controlled by the relay coil in the protection control circuit 110. When the relay is activated, the states of S1 and S2 will change.

[0052] Optionally, the first connection end of the second switch 140 is connected between the protection control circuit 110 and the device end on the first bus, the second connection end of the second switch 140 is connected to the first connection end of the recovery control circuit 120, and the second connection end of the recovery control circuit 120 is connected between the bus end and the device end of the second bus.

[0053] like Figure 3 As shown, when the two-bus system works normally, S2 is in the disconnected state, and at this time, the recovery control circuit 120 is in the open circuit state.

[0054] Optionally, the resettable fuse 150 is a fuse whose closed or open state is controlled by temperature. When the temperature of the resettable fuse 150 is too high, the resettable fuse 150 is disconnected. When the temperature of the resettable fuse 150 returns to below the target temperature, the resettable fuse 150 will close again.

[0055] Figure 4 FIG. 1 is a schematic diagram of an optional two-bus system structure when the device end is short-circuited. Since the recovery control circuit 120 is in an open circuit state when the two-bus system is working normally, Figure 4 The recovery control circuit 120 is not shown in FIG. Figure 4 As shown, when the device end is short-circuited, the resettable fuse 150 overheats and performs bus protection, and the resettable fuse 150 is disconnected. At this time, the short-circuit isolation component is disconnected, and the protection control circuit 110 is connected in series in the first bus to form a loop, and the protection control circuit 110 is in a connected state.

[0056] Optionally, the protection control circuit 110 includes a first rectifier bridge 111 and a relay coil 112 .

[0057] Optionally, the input end of the first rectifier bridge 111 is connected to the first bus, and the output end of the first rectifier bridge 111 is connected in parallel to the relay coil 112 .

[0058] Optionally, the protection control circuit further includes a light emitting diode 113 , and the light emitting diode 113 is connected in parallel with the relay coil 112 .

[0059] Figure 5 FIG. 1 is a schematic diagram of an optional protection control circuit. Figure 5 As shown, after the protection control circuit 110 is powered on, the first rectifier bridge 111 in the protection control circuit 110 rectifies the uncertain positive and negative voltages input by the bus, and outputs the rectified current to the two output ends of the first rectifier bridge 111 according to a preset polarity. The light-emitting diode 113 emits light after being powered on to indicate a fault state to provide a fault prompt to the user. The relay coil 112 causes the relay to operate after being powered on to change the states of the first switch 130 and the second switch 140. The first switch 130 is converted from a closed state during normal operation to an open state, and the second switch 140 is converted from an open state during normal operation to a closed state.

[0060] Optionally, after the first switch 130 is disconnected, the first bus is short-circuited, and the temperature of the resettable fuse 150 will gradually recover to below the target temperature, and then the resettable fuse 150 will return to a closed state, thereby avoiding the resettable fuse 150 from heating up all the time and extending the service life of the resettable fuse 150. At this time, since the first switch 130 is in the disconnected state, the first bus continues to remain in the disconnected state to protect the safety of the bus.

[0061] Optionally, the protection control circuit 110 is specifically used to implement the following functions:

[0062] In the non-powered state, the first switch 130 is controlled to be in a closed state, and the second switch 140 is controlled to be in an open state;

[0063] When switching from the non-powered state to the powered state, controlling the first switch 130 to switch from the closed state to the open state, and controlling the second switch 140 to switch from the open state to the closed state; and

[0064] When a relay control signal is received in the power-on state, the first switch 130 is controlled to switch from an open state to a closed state, and the second switch 140 is controlled to switch from a closed state to an open state.

[0065] Figure 6 FIG. 1 is a schematic diagram of another optional two-bus system structure for device-side recovery time. Figure 6As shown, after the fault on the device side is resolved and the device side is converted from a short-circuit state to a connected state, the protection control circuit 110 in the connected state can normally supply power to the back-end device side. At this time, the recovery control circuit 120 and the back-end device side are both powered on.

[0066] Optionally, the recovery control circuit 120 includes a second rectifier bridge 121 and a photocoupler 122;

[0067] The input end of the second rectifier bridge 121 is connected to the first bus and the second bus respectively, and the output end of the second rectifier bridge 121 is connected to the input end of the photoelectric coupler 122 respectively;

[0068] The photocoupler 122 outputs a relay control signal to the relay coil 112 in the protection control circuit 110 when powered on.

[0069] Figure 7 FIG. 1 is a schematic diagram of an optional recovery control circuit. Figure 7 As shown, the second rectifier bridge 121 rectifies the uncertain positive and negative voltages input by the bus, and outputs the rectified current to the two output ends of the second rectifier bridge 121 according to a preset polarity. After being powered on, the photocoupler 122 outputs a relay control signal to the relay coil 112 in the protection control circuit 110.

[0070] Optionally, the photocoupler 122 is mainly used to achieve physical isolation. Since the voltage transmitted by the bus is relatively high, and sending the relay control signal only requires high and low level signals, the high voltage can be converted into a low level through the photocoupler 122.

[0071] Optionally, after the relay coil 112 in the protection control circuit 110 receives the relay control signal, the relay is controlled to operate again, and the first switch 130 is converted from the open state at the moment of short circuit to the closed state. Since the self-resetting fuse 150 has been connected through temperature recovery before, the first bus is in the connected state at this time, and the protection control circuit 110 is connected to the first bus in a short-circuit state again, and the second switch 140 is converted from the closed state at the moment of short circuit to the open state. At this time, the recovery control circuit 120 is open again, and the voltage drop-free bus short-circuit isolation system is restored to the protection state of the two-bus system under normal working conditions.

[0072] The technical solution of the embodiment of the present invention configures a protection control circuit, a recovery control circuit, a first switch, a second switch and a resettable fuse in a voltage-drop-free bus short-circuit isolation system. The first switch and the resettable fuse are connected in series on the first bus and are connected between the bus end and the device end as a short-circuit isolation component. The protection control circuit is connected in parallel with the short-circuit isolation component. The recovery control circuit is connected in parallel between the first bus and the second bus at the bus end and is connected to the first bus through the second switch. The first switch is set as the normally closed end of the relay, and the second switch is set as the normally open end of the relay. Short-circuit protection of the two-bus system can be achieved through the physical characteristics of each electronic device. The series connection of the switch and the resettable fuse in the bus avoids the problems of reduced bus voltage drop and bus current consumption, and ensures the load capacity of the bus. In addition, short-circuit protection based on physical characteristics does not require logical control, which reduces the complexity of the two-bus system, reduces costs, improves output efficiency, and is stable and reliable. At the same time, it also has the function of fault indication alarm. When the fault is removed, the two-bus system can also restore the normal working state in time to ensure normal power supply and communication.

[0073] Embodiment 2

[0074] Figure 8 This is a flow chart of a bus device short circuit protection method provided in the second embodiment of the present invention. This embodiment is applicable to the case where a device in the two bus systems is short-circuited to protect the two bus systems from short circuits. The method can be performed by the protection control circuit, the recovery control circuit, the first switch, the second switch and the self-recovery fuse in the non-voltage drop type bus short circuit isolation system. Figure 8 As shown, the method includes:

[0075] S210. When all device ends in the second bus system are in normal working state, the protection control circuit is controlled by the short-circuit isolation component to remain in an unpowered state, and the connection between the recovery control circuit and the bus end is disconnected by the second switch in the open state.

[0076] Optionally, when all device ends in the two-bus system are in normal working condition, the first switch and the resettable fuse can be regarded as wires connected in series on the first bus, the protection control circuit remains in an unpowered state, and the second switch is disconnected, so that the recovery control circuit is open.

[0077] S220. When a short circuit occurs in a device in the two-bus system, the power supply of the first bus to each device end is disconnected by a self-recovery fuse, and the protection control circuit is switched from an unpowered state to a powered state by disconnecting the short-circuit isolation component.

[0078] S230. Through the protection control circuit, when switching from the non-powered state to the powered state, the first switch is switched from the closed state to the open state, and the second switch is switched from the open state to the closed state, so that the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end in a connected manner, and when the self-recovery fuse is restored to connection, the power supply connection between the first bus and each device end is still disconnected.

[0079] Optionally, after the first switch is disconnected, the first bus remains in an open circuit state, the temperature of the resettable fuse gradually decreases, and after the temperature is lower than the target temperature, the resettable fuse returns to a connected state.

[0080] S240, when the short-circuited device end in the second bus system recovers from the short-circuited state to the normal working state, the recovery control circuit switches from the non-powered state to the powered state.

[0081] S250. When switching from a non-powered state to a powered state, a relay control signal is output to a relay coil in the protection control circuit through the recovery control circuit.

[0082] S260. When a relay control signal is received through the protection control circuit in the power-on state, the first switch is controlled to switch from the open state to the closed state, and the second switch is controlled to switch from the closed state to the open state, so as to connect the short-circuit isolation component in series on the first bus in a connected manner, restore the normal power supply of the first bus, and realize that when the short-circuit isolation component is connected, the protection control circuit is connected in parallel with the short-circuit isolation component in a short-circuit state, and the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end in an open-circuit state.

[0083] The technical solution of the embodiment of the present invention can avoid the problems of bus voltage drop reduction and bus current consumption when the two-bus system is working normally, ensure the load capacity of the bus, and disconnect the bus in time to perform circuit protection when a short circuit occurs at the device end. At the same time, when the fault is eliminated, the two-bus system can also restore the normal working state in time to ensure normal power supply and communication.

Claims

1. A bus short-circuit isolation system without voltage drop, characterized in that: Configured in a two-bus system, each device end in the two-bus system is connected in parallel between a first bus and a second bus at the bus end, and the isolation system includes a protection control circuit, a recovery control circuit, a first switch, a second switch and a self-recovery fuse; The first switch and the resettable fuse are connected in series on the first bus, and are connected between the bus end and the device end as a short-circuit isolation component; the protection control circuit is connected in parallel with the short-circuit isolation component; the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end, and is connected to the first bus through the second switch; the first connection end of the second switch is connected between the protection control circuit on the first bus and the device end, the second connection end of the second switch is connected to the first connection end of the recovery control circuit, and the second connection end of the recovery control circuit is connected between the bus end and the device end of the second bus; The protection control circuit is used to control the action of the relay through the relay coil when power is on; the recovery control circuit is used to output a relay control signal to the protection control circuit when power is on, so as to control the action of the relay through the relay coil in the protection control circuit; The first switch is the normally closed end of the relay, and the second switch is the normally open end of the relay; when the protection control circuit controls the relay to operate, the opening and closing states of the first switch and the second switch change.

2. The system according to claim 1, characterized in that The protection control circuit is specifically used to realize the following functions: When the power is not supplied, the first switch is controlled to be in a closed state, and the second switch is controlled to be in an open state; When switching from the non-powered state to the powered state, the first switch is controlled to switch from the closed state to the open state, and the second switch is controlled to switch from the open state to the closed state; as well as When a relay control signal is received in the power-on state, the first switch is controlled to switch from the open state to the closed state, and the second switch is controlled to switch from the closed state to the open state.

3. The system according to claim 1, characterized in that The protection control circuit includes a first rectifier bridge and a relay coil; The input end of the first rectifier bridge is connected to the first bus, and the output end of the first rectifier bridge is connected in parallel with the relay coil.

4. The system according to claim 3, characterized in that The protection control circuit also includes a light emitting diode, which is connected in parallel with the relay coil.

5. The system according to claim 3, characterized in that The recovery control circuit includes a second rectifier bridge and a photoelectric coupler; The input end of the second rectifier bridge is respectively connected to the first bus and the second bus, and the output end of the second rectifier bridge is respectively connected to the input end of the photoelectric coupler; The photoelectric coupler outputs a relay control signal to the relay coil in the protection control circuit when powered on.

6. A bus device short-circuit protection method, applied to the non-voltage drop type bus short-circuit isolation system as claimed in any one of claims 1 to 5, characterized in that: include: When all the equipment ends in the two-bus system are in normal working state, the protection control circuit is controlled by the short-circuit isolation component to remain in an unpowered state, and the connection between the recovery control circuit and the bus end is disconnected by the second switch in the open state.

7. The method according to claim 6, characterized in that The method further comprises: When a device in the two-bus system is short-circuited, the power supply from the first bus to each device end is disconnected through a self-recovery fuse, and the protection control circuit is switched from a non-powered state to a powered state by disconnecting the short-circuit isolation component; By protecting the control circuit, when switching from an unpowered state to a powered state, the first switch is switched from a closed state to an open state, and the second switch is switched from an open state to a closed state, so that the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end in a connected manner, and when the self-recovery fuse is restored to connectivity, the power supply connection between the first bus and each device end is still disconnected.

8. The method according to claim 7, characterized in that The method further comprises: When the device end that has a short circuit in the two-bus system recovers from the short circuit state to the normal working state, the recovery control circuit switches from the non-powered state to the powered state; By restoring the control circuit, when switching from the non-powered state to the powered state, a relay control signal is output to the relay coil in the protection control circuit.

9. The method according to claim 8, characterized in that After outputting the relay control signal to the relay coil in the protection control circuit, the method further includes: Through the protection control circuit, when a relay control signal is received in the power-on state, the first switch is controlled to switch from the open state to the closed state, and the second switch is controlled to switch from the closed state to the open state, so that the short-circuit isolation component is connected in series on the first bus in a connected manner, and the normal power supply of the first bus is restored. When the short-circuit isolation component is connected, the protection control circuit is connected in parallel with the short-circuit isolation component in a short-circuit state, and the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end in an open-circuit state.

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