Voltage-drop-free bus short-circuit isolation system and bus equipment short-circuit protection method

Abstract

The invention discloses a voltage-drop-free bus short-circuit isolation system and a bus equipment short-circuit protection method. The system comprises 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 jointly serve as a short-circuit isolation assembly to be connected between the bus end and the equipment end; the protection control circuit is connected in parallel with the short-circuit isolation assembly. The recovery control circuit is connected in parallel between the first bus and the second bus of the bus end, and is connected with the first bus through the second switch; the protection control circuit is used for controlling the relay to act through the relay coil during electrification; the recovery control circuit is used for outputting a relay control signal to the protection control circuit when being electrified; the first switch is a normally-closed end of the relay, and the second switch is a normally-open end of the relay. By adopting the above technical scheme, circuit break protection can be carried out when the equipment end is short-circuited, and normal power supply and communication of the equipment end can be automatically recovered when a fault is removed.

Description

Technical Field

[0001] This invention relates to the field of circuit protection technology, and in particular to a voltage drop-free bus short-circuit isolation system and a short-circuit protection method for bus devices. Background Technology

[0002] Bus communication is a method of exchanging data, address, and control information between various components in a hardware system. The bus is the physical channel connecting various 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. Due to the large number of devices on the bus and the different operating conditions of each device, failures can occur in many cases. A short circuit in a faulty device can paralyze the entire bus communication, resulting in unpredictable losses.

[0003] To address the issue of bus communication failure caused by device short circuits, a bus short-circuit isolator can be used to isolate the fault point and prevent it from affecting other devices on the bus. Currently, commercially available short-circuit isolators typically use a sampling resistor connected in series with the bus. However, the sampling resistor has a certain resistance value, which may lead to a decrease in bus voltage drop. Furthermore, after the signal is acquired, a controller is required for logic control, increasing the complexity of the system. Summary of the Invention

[0004] This invention provides a voltage drop-free bus short-circuit isolation system and a bus device short-circuit protection method, which can disconnect the device when a short circuit occurs and automatically restore normal power supply and communication to the device when the fault is cleared.

[0005] According to one aspect of the present invention, a voltage drop-free bus short-circuit isolation system is provided, configured in a two-bus system, wherein each device terminal in the two-bus system is connected in parallel between a first bus and a second bus at the bus terminal, and the isolation system includes a protection control circuit, a recovery control circuit, a first switch, a second switch, and a self-resetting fuse;

[0006] The first switch and the self-resetting fuse 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 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 relay to operate via the relay coil when energized; the recovery control circuit is used to output a relay control signal to the protection control circuit when energized, so as to control the relay to operate via the relay coil in the protection control circuit.

[0008] The first switch is the normally closed terminal of the relay, and the second switch is the normally open terminal of the relay. When the relay in the protection controller circuit is activated, the open and closed states of the first and second switches change.

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

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

[0011] When the power is off, the first switch is controlled to be closed and the second switch is controlled to be open.

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

[0013] When a relay control signal is received while the circuit is powered on, 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 terminal of the first rectifier bridge is connected to the first bus, and the output terminal of the first rectifier bridge is connected in parallel with the relay coil.

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

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

[0018] The input terminals of the second rectifier bridge are connected to the first bus and the second bus respectively, and the output terminals of the second rectifier bridge are connected to the input terminals of the optocouplers respectively.

[0019] When energized, the optocoupler outputs a relay control signal to the relay coil in the protection control circuit.

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

[0021] When all devices in the two-bus system are in normal working condition, the short-circuit isolation component controls the protection control circuit to remain in an unpowered state, and the connection between the control circuit and the bus terminal is disconnected by the second switch which is in the open state.

[0022] Optionally, the method further includes:

[0023] When a device in a two-bus system experiences a short circuit, the power supply from the first bus to each device is disconnected by a self-resetting 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 using the protection control circuit, when switching from a non-powered state to a 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. This connects the recovery control circuit in parallel between the first bus and the second bus at the bus end, and ensures that when the self-resetting fuse is restored to connection, the power supply connection between the first bus and each device is still disconnected.

[0025] Optionally, the method further includes:

[0026] When a device in a two-bus system recovers from a short-circuit state to a normal operating state, the recovery control circuit switches from a non-powered state to a powered state.

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

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

[0029] When the protection control circuit receives a relay control signal while the circuit is powered on, it controls the first switch to switch from the open state to the closed state and controls the second switch to switch from the closed state to the open state. This connects the short-circuit isolation component in series on the first bus, restoring the normal power supply to the first bus. 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 and second buses at the bus end in an open-circuit state.

[0030] The technical solution of this invention, through configuring a protection control circuit, a recovery control circuit, a first switch, a second switch, and a self-resetting fuse in a voltage drop-free bus short-circuit isolation system, wherein the first switch and the self-resetting fuse 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 is connected in parallel with the short-circuit isolation component, and the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end and connected to the first bus through the second switch, wherein the first switch is set as the normally closed terminal of a relay and the second switch is set as the normally open terminal of a relay, can achieve short-circuit protection of the two-bus system through the physical characteristics of each electronic device, and the series connection of the switch and the self-resetting fuse in the bus avoids the problems of reduced bus voltage drop and bus current consumption, ensuring the load capacity of the bus, and, based on the physical characteristics, short-circuit protection does not require logic control, reducing the complexity of the two-bus system, reducing costs, improving output efficiency, and ensuring stability and reliability, while also having the function of fault indication and alarm, and when the fault is cleared, the two-bus system can also promptly restore normal working state, ensuring normal power supply and communication.

[0031] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a voltage drop-free bus short-circuit isolation system according to Embodiment 1 of the present invention;

[0034] Figure 2 This 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 This is a schematic diagram of another voltage drop-free bus short-circuit isolation system provided according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of a two-bus system structure at the moment of short circuit at the device end according to an embodiment of the present invention;

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

[0038] Figure 6 This is a schematic diagram of a two-bus system structure for device-side recovery time according to an embodiment of the present invention;

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

[0040] Figure 8 This is a flowchart of a short-circuit protection method for a bus device according to Embodiment 2 of the present invention. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort 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, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] Example 1

[0044] Figure 1 This is a schematic diagram of a voltage drop-free bus short-circuit isolation system provided in Embodiment 1 of the present invention, as shown below. Figure 1 As shown, a voltage drop-free bus short-circuit isolation system is configured in a two-bus system. Each device in the two-bus system is connected in parallel between the first bus and the second bus. The voltage drop-free bus short-circuit isolation system includes a protection control circuit 110, a recovery control circuit 120, a first switch 130, a second switch 140, and a self-resetting fuse 150.

[0045] Figure 2 This is a schematic diagram of the sampling resistor in an optional existing short-circuit isolator in a two-bus system. Figure 2 As shown, existing short-circuit isolators connect a sampling resistor in series on one bus in a two-bus system. By acquiring the voltage across the sampling resistor, they determine if there is a short circuit or overcurrent on the bus. If a short circuit occurs, the back-end controller can disconnect the devices in the two-bus system. However, the sampling resistor has a certain resistance value, which may reduce the bus voltage drop and decrease the bus's load capacity. Furthermore, to perform voltage acquisition and monitoring, power may need to be drawn from the bus, further consuming bus current. Additionally, the back-end controller needs to process the analog signal from the sampling resistor, and this logical processing increases the complexity of the short-circuit isolator, resulting in low efficiency at a high cost.

[0046] Understandably, in order to solve the aforementioned problems of existing short-circuit isolators, the present invention connects the first switch 130 and the self-resetting fuse 150 in series on the first bus. The first switch 130 and the self-resetting fuse 150 are similar to wires and do not share the voltage on the first bus, thus effectively ensuring the load-carrying capacity of the bus. When the two-bus system is working normally, the first switch 130 and the self-resetting fuse 150 are turned on, thereby connecting the protection control circuit 110 to the first bus in a short-circuit manner. The protection control circuit 110 is not powered, and the second switch 140 is in the open state, and the recovery control circuit 120 is connected to the two-bus system in an open-circuit manner. At this time, neither the protection control circuit 110 nor the recovery control circuit 120 consumes the current of the two-bus system, nor does it cause a decrease in bus voltage drop.

[0047] Optionally, in a two-bus system, the bus end includes a first bus and a second bus. Both the first bus and the second bus can transmit signals and can also supply 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 self-resetting 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 to operate via the relay coil when energized; the recovery control circuit 120 is used to output a relay control signal to the protection control circuit 110 when energized, so as to control the relay to operate via the relay coil in the protection control circuit 110.

[0050] Optionally, the first switch 130 is the normally closed terminal of the relay, and the second switch 140 is the normally open terminal of the relay; when the relay in the protection controller circuit is activated, the open and closed states of the first switch 130 and the second switch 140 change.

[0051] Figure 3 This is a schematic diagram of another optional zero-dropout bus short-circuit isolation system. (See diagram below.) 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. Positive and negative signs are used to distinguish the first and second buses, but in actual two-bus systems, the first and second buses are not polarized; their polarities may be interchanged. Devices 1 to n are connected in parallel between the first and second buses, respectively. 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 terminal of the second switch 140 is connected between the protection control circuit 110 on the first bus and the device terminal, and the second connection terminal of the second switch 140 is connected to the first connection terminal of the recovery control circuit 120, and the second connection terminal of the recovery control circuit 120 is connected between the bus terminal of the second bus and the device terminal.

[0053] like Figure 3 As shown, when the two-bus system is working normally, S2 is in the open state, and at this time the recovery control circuit 120 is in the open 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 will open, and when the temperature of the resettable fuse 150 returns to below the target temperature, the resettable fuse 150 will close again.

[0055] Figure 4 This is a schematic diagram of a two-bus system structure under an optional device-side short-circuit condition. Since the recovery control circuit 120 is in an open-circuit state during normal operation of the two-bus system, therefore... Figure 4 The recovery control circuit 120 is not shown in the diagram. Figure 4 As shown, when a short circuit occurs at the device end, the resettable fuse 150 overheats and performs bus protection. The resettable fuse 150 then disconnects, and the short circuit isolation component disconnects. 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 the connected state.

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

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

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

[0059] Figure 5 This is a schematic diagram of an optional protection control circuit. (Example) 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 voltage input to the bus and outputs the rectified current to the two output terminals of the first rectifier bridge 111 according to the preset polarity. The light-emitting diode 113 lights up after being powered on to indicate the fault status and to provide a fault prompt to the user. After the relay coil 112 is powered on, it causes the relay to operate to change the state of the first switch 130 and the second switch 140. The first switch 130 changes from the closed state during normal operation to the open state, and the second switch 140 changes from the open state during normal operation to the closed state.

[0060] Optionally, after the first switch 130 is turned off, the first bus is disconnected, and the temperature of the resettable fuse 150 will gradually return to below the target temperature. Then, the resettable fuse 150 will return to the closed state, which avoids the resettable fuse 150 from overheating and extends the service life of the resettable fuse 150. At this time, since the first switch 130 is in the open state, the first bus remains in the open state to protect the bus safety.

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

[0062] When the power is off, the first switch 130 is closed and the second switch 140 is open.

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

[0064] When a relay control signal is received while the circuit is powered on, the first switch 130 is switched from the open state to the closed state, and the second switch 140 is switched from the closed state to the open state.

[0065] Figure 6 This is a schematic diagram of a two-bus system architecture for an alternative device-side recovery time. (Example:) Figure 6As shown, after the fault is resolved at the device end and the device end changes from a short circuit state to a closed state, the protection control circuit 110, which is in the connected state, can supply power to the downstream device end normally. At this time, the recovery control circuit 120 and the downstream device end are both in a powered state.

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

[0067] The input terminals of the second rectifier bridge 121 are connected to the first bus and the second bus respectively, and the output terminals of the second rectifier bridge 121 are connected to the input terminals of the optocoupler 122 respectively.

[0068] When energized, the optocoupler 122 outputs a relay control signal to the relay coil 112 in the protection control circuit 110.

[0069] Figure 7 This 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 voltage input to the bus and outputs the rectified current to the two output terminals of the second rectifier bridge 121 according to the preset polarity. After the optocoupler 122 is powered on, it outputs a relay control signal to the relay coil 112 in the protection control circuit 110.

[0070] Optionally, the optocoupler 122 is mainly used to achieve physical isolation. Since the voltage transmitted on the bus is high, while only high and low level signals are needed to send relay control signals, the high voltage can be converted to a low level by the optocoupler 122.

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

[0072] The technical solution of this invention, through configuring a protection control circuit, a recovery control circuit, a first switch, a second switch, and a self-resetting fuse in a voltage drop-free bus short-circuit isolation system, wherein the first switch and the self-resetting fuse 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 is connected in parallel with the short-circuit isolation component, and the recovery control circuit is connected in parallel between the first bus and the second bus at the bus end and connected to the first bus through the second switch, wherein the first switch is set as the normally closed terminal of a relay and the second switch is set as the normally open terminal of a relay, can achieve short-circuit protection of the two-bus system through the physical characteristics of each electronic device, and the series connection of the switch and the self-resetting fuse in the bus avoids the problems of reduced bus voltage drop and bus current consumption, ensuring the load capacity of the bus, and, based on the physical characteristics, short-circuit protection does not require logic control, reducing the complexity of the two-bus system, reducing costs, improving output efficiency, and ensuring stability and reliability, while also having the function of fault indication and alarm, and when the fault is cleared, the two-bus system can also promptly restore normal working state, ensuring normal power supply and communication.

[0073] Example 2

[0074] Figure 8 This is a flowchart of a bus device short-circuit protection method provided in Embodiment 2 of the present invention. This embodiment is applicable to situations where a device in a two-bus system experiences a short circuit, providing short-circuit protection for the two-bus system. The method can be executed by a protection control circuit, a recovery control circuit, a first switch, a second switch, and a self-resetting fuse in a voltage-drop-rate bus short-circuit isolation system. Figure 8 As shown, the method includes:

[0075] S210. When all devices in the two-bus system are in normal working condition, the short-circuit isolation component controls the protection control circuit to remain in an unpowered state, and the second switch, which is in the open state, disconnects the connection between the restoration control circuit and the bus.

[0076] Optionally, when all devices in the two-bus system are in normal working condition, the first switch and the self-resetting fuse can be regarded as wires connected in series on the first bus, the protection control circuit remains unpowered, and the second switch is opened, so that the reset control circuit is open.

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

[0078] S230. Through the protection control circuit, when switching from the unpowered 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 as to connect the recovery control circuit in parallel between the first bus and the second bus at the bus end in a connected manner, and realize that when the self-resetting 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 turned off, the first bus remains in an open circuit state, the temperature of the resettable fuse gradually decreases, and after it falls below the target temperature, the resettable fuse returns to the connected state.

[0080] S240. When a device in a two-bus system recovers from a short-circuit state to a normal operating state, the recovery control circuit switches from a non-powered state to a powered state.

[0081] S250: By restoring the control circuit, when switching from a non-powered state to a powered state, a relay control signal is output to the relay coil in the protection control circuit.

[0082] S260. When the protection control circuit receives a relay control signal while the circuit is powered on, it controls the first switch to switch from the open state to the closed state and controls the second switch 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 this invention, through the cooperation of the protection control circuit, the recovery control circuit, the first switch, the second switch, and the self-resetting fuse in the voltage drop-free bus short-circuit isolation system to perform short-circuit protection, can avoid the problems of reduced bus voltage drop and bus current consumption when the two-bus system is working normally, ensuring the load capacity of the bus. When a short circuit occurs at the device end, the bus is disconnected in time for circuit protection. At the same time, when the fault is cleared, the two-bus system can also restore normal working state in time, ensuring 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 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 relay in the protection controller circuit is actuated, 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 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.

3. 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.

4. 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.

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

6. The system according to claim 4, 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.

7. A bus device short-circuit protection method, applied to the non-voltage drop type bus short-circuit isolation system according to any one of claims 1 to 6, 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.

8. The method according to claim 7, 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.

9. The method according to claim 8, 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.

10. The method according to claim 9, 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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