Ring network controller including communication equipment and control method

Abstract

A ring network controller and control method containing communication equipment includes: a lightning arrester, a switch device, a control device, and a communication device; the lightning arrester is connected in parallel with the switch device; the communication device is connected to the control device and is used to receive in real time the tripping signal generated when the ring network circuit is closed; the control device is connected to the switch device and is used to collect ring network circuit data and control the switch device to open or close according to the ring network circuit data and the received tripping signal; the lightning arrester is used to provide overvoltage protection; the switch device is used to construct and eliminate breakpoints and bear the corresponding voltage difference. By installing the ring network controller of this solution in the ring network circuit, it is possible to achieve the situation where the ring is closed first and then opened during the switching operation of the line. The switch device constructs the breakpoint when closing the ring and eliminates the breakpoint when opening the ring, effectively eliminating the closing impact current generated by the ring network circuit, solving the problem of power outages during the transfer of line loads due to reasons such as line maintenance, and improving the power supply reliability of important loads.

Description

Technical Field

[0001] The present invention relates to the field of live ring closing of distribution networks, and in particular to a ring network controller containing communication equipment and a control method thereof. Background Art

[0002] Grid users are increasingly demanding higher reliability in their power supply. Industrial users, in particular, are highly sensitive to power outages, with even short outages potentially causing significant economic losses. However, distribution network outages for maintenance are frequent, and distribution network voltage levels are not limited to 10kV, but include at least 6kV, 10kV, 20kV, or 35kV. Medium and low voltage distribution networks typically employ a closed-loop design with open-loop operation. This involves a looped network operating with each power source supplying a portion of the load. Currently, for load reversal and line maintenance, the unbundling process typically involves first opening the circuit breaker at the target unbundling position and then closing it at the original unbundling position—a "open-first, close-later" approach. This process can cause partial power outages. Adopting a "close-first, open-later" approach—first closing the circuit breaker at the original unbundling position (closing the loop) and then opening it at the target unbundling position—can reduce power outages and improve power supply reliability.

[0003] However, directly performing a power-off and disconnection operation without interruption carries significant risks. This is because closing a loop directly in an open-loop distribution network presents the following issues: A voltage difference exists between the two ends of the loop before closing, generating a large surge current during closing and a circulating current in the electromagnetic loop network after closing. This surge current can also cause malfunctions in the distribution network's relay protection, leading to faults. Furthermore, on-site loop closing operations are conducted based on the operator's experience, resulting in a high degree of randomness in the results, potentially posing a safety hazard to related equipment and operators. Summary of the Invention

[0004] In order to solve the problem of ring closing impact occurring when closing a distribution network in the prior art, the present invention provides a ring network controller including a communication device and a control method.

[0005] The technical solution provided by the present invention is:

[0006] A ring network controller including communication equipment, comprising:

[0007] Lightning arresters, switchgear, control equipment and communications equipment;

[0008] The lightning arrester is connected in parallel with the switchgear;

[0009] The communication device is connected to the control device and is used to receive in real time the opening signal generated when the ring network circuit is closed;

[0010] The control device is connected to the switch device and is used to collect ring network circuit data and control the switch device to open or close according to the ring network circuit data and the received opening signal;

[0011] The lightning arrester is used for overvoltage protection;

[0012] The switchgear is used to construct and eliminate breakpoints and bear the corresponding voltage differences;

[0013] The opening time of the switchgear should be less than 0.3s and the closing time should be less than 10ms;

[0014] The tripping signal is an analog or digital signal.

[0015] Preferably, the switching device may be one or more of a mechanical switch and a power electronic device.

[0016] Preferably, the switch device comprises:

[0017] Mechanical switches and power electronics;

[0018] The mechanical switch and power electronic device are connected in series or in parallel and then connected in parallel with the lightning arrester;

[0019] The mechanical switch and the power electronic device are also connected to the control device.

[0020] Preferably, the switching device may be one or more of a mechanical switch connected in series with a resistive-inductive element or a power electronic device connected in series with a resistive-inductive element.

[0021] Preferably, the switch device comprises:

[0022] Mechanical switches with series resistance and inductive elements and power electronic devices with series resistance and inductive elements;

[0023] The mechanical switch of the series resistive-inductive element is connected in parallel with the power electronic device of the series resistive-inductive element and then connected in parallel with the lightning arrester;

[0024] The mechanical switch of the series-connected resistive-inductive element and the power electronic device of the series-connected resistive-inductive element are connected to the control device.

[0025] Preferably, the power electronic device should be able to withstand the short-circuit impact current of the ring network circuit.

[0026] Preferably, the mechanical switch should be able to withstand the short-circuit impact current of the ring network circuit, and the terminal withstand voltage level of the mechanical switch may not be equal to the insulation voltage level of the mechanical switch to the ground;

[0027] The mechanical switch can operate in three phases separately or in a three-phase linkage manner.

[0028] Preferably, the arrester may be a metal oxide arrester, a valve type arrester, a metal oxide arrester connected in series with a resistive inductive element, or a valve type arrester connected in series with a resistive inductive element;

[0029] The continuous operating voltage of the lightning arrester should be greater than the maximum break voltage that occurs at the installation location of the ring network controller during steady-state operation.

[0030] Preferably, the control device includes:

[0031] Interconnected measurement modules and control modules;

[0032] The control module is connected to the mechanical switch and the power electronic device;

[0033] The measuring module is used to collect the instantaneous voltage difference at both ends of the ring network controller, and formulate an opening instruction or a closing instruction according to the instantaneous voltage difference at both ends of the ring network controller and the received opening signal;

[0034] The control module is used to control the mechanical switch to be disconnected or closed according to the opening instruction or the closing instruction.

[0035] Preferably, the measurement module may be a conventional mutual inductor or sensor.

[0036] Preferably, the measurement module may also use a breakdown diode BOD to determine the instantaneous difference in the measured voltage;

[0037] The breakdown diode BOD is connected in parallel at both ends of the ring network controller;

[0038] The breakdown voltage of the breakdown diode BOD is equal to the set voltage difference instantaneous threshold.

[0039] Preferably, the control device may be a device that takes energy from voltage and supplies energy.

[0040] Preferably, the lightning arrester, power electronic device, mechanical switch, measurement module, control module and communication equipment are fixedly installed in the ring network circuit.

[0041] Preferably, the lightning arrester, power electronic device and mechanical switch are fixedly installed in the ring network circuit;

[0042] When the ring network circuit is closed or opened, the measuring module, the control module and the communication device are connected to the lightning arrester, the power electronic device and the mechanical switch as the moving parts.

[0043] Preferably, when there is a switching device in the ring network circuit that can be used in parallel with the ring network controller, the lightning arrester, power electronic device, mechanical switch, measurement module, control module and communication equipment can be connected as mobile parts and the switching device that can be used in parallel with the ring network controller to perform ring closing and ring opening operations.

[0044] Preferably, when the ring network circuit is a distribution network with single ring network connection, one ring network controller is installed in the ring network circuit;

[0045] When the ring network circuit is a double-ring network connection distribution network, two ring network controllers are installed in the ring network circuit;

[0046] When the ring network circuit is an N-1 wiring distribution network, one ring network controller is installed in the spare bus.

[0047] A control method for a ring network controller containing communication equipment, comprising:

[0048] When the ring network circuit is closed, if the instantaneous voltage difference across the ring network controller is less than a set threshold and the communication device receives a tripping signal, the measurement module generates a tripping instruction; otherwise, no tripping instruction is generated, and the current state of the mechanical switch in the ring network control is maintained; the control device in the ring network controller controls the switch device in the ring network controller to construct a breakpoint according to the tripping instruction, thereby eliminating the closing impact in the ring network circuit;

[0049] When the ring network circuit is unhooked, the control device controls the switch device to eliminate the breakpoint, bypass the lightning arrester, and restore the voltage of the ring network circuit.

[0050] Preferably, when the ring network circuit is closed, the ring network controller receives a tripping signal through a communication device, and a control device in the ring network controller controls a switch device in the ring network controller to construct a breakpoint according to the tripping signal and the instantaneous voltage difference, thereby eliminating a closing impact in the ring network circuit, including:

[0051] When the ring network circuit is closed, if the instantaneous voltage difference across the ring network controller is less than a set threshold and the communication device receives a trip signal, the measurement module generates a trip instruction; otherwise, no trip instruction is generated and the current state of the mechanical switch in the ring network control is maintained;

[0052] The control module controls the switch device to construct a breakpoint according to the opening instruction, thereby eliminating the closing impact in the ring network circuit;

[0053] The time from the generation of the trip signal, the transmission of the trip signal, the reception of the trip signal to the completion of the tripping of the switching device should ensure that the fastest-acting line overcurrent protection in the line does not operate.

[0054] Preferably, the control module controls the switch device to configure a breakpoint according to the opening instruction, including:

[0055] The control module controls the mechanical switch in the switch device to open according to the opening instruction, triggers the power electronic device in the switch device after a first set delay, and cuts off the power electronic device after a second set delay;

[0056] When the first set delay is reached, the mechanical switch has not yet started to open;

[0057] When the second set delay is reached, the mechanical switch has been opened and the arc has been extinguished.

[0058] Preferably, when the ring network circuit is unhooked, the control device controls the switch device to eliminate the breakpoint, bypass the lightning arrester, and restore the voltage of the ring network circuit, including:

[0059] The measurement module in the control device collects the instantaneous voltage difference between the two ends of the ring network controller;

[0060] When the ring network circuit is unlocked, if the instantaneous voltage difference across the ring network controller is greater than a set threshold, the measurement module generates a closing instruction; otherwise, no closing instruction is generated, and the current state of the mechanical switch in the ring network control is maintained;

[0061] The control module controls the switch device to eliminate the breakpoint, bypass the lightning arrester, and restore the ring network circuit voltage according to the closing instruction;

[0062] The time from the moment when the instantaneous voltage difference at both ends of the ring network controller is greater than the threshold to the completion of closing should be within 10ms.

[0063] Preferably, the control module controls the switching device to eliminate the breakpoint according to the closing instruction, including:

[0064] The control module controls the triggering of the power electronic device and the closing of the mechanical switch in the switch device according to the closing instruction, and cuts off the power electronic device after a third set delay;

[0065] When the third set delay is reached, the mechanical switch completes closing and carries the load current.

[0066] Preferably, the control module controls the switching device to eliminate the breakpoint according to the closing instruction, including:

[0067] If the mechanical switch is in the closed state, the control module controls the mechanical switch in the switch device to maintain the closed state according to the closing instruction.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] The technical solution provided by the present invention includes: a lightning arrester, a switch device, a control device and a communication device; the lightning arrester is connected in parallel with the switch device; the communication device is connected to the control device and is used to receive in real time the tripping signal generated when the ring network circuit is closed; the control device is connected to the switch device and is used to collect the ring network circuit data and control the switch device to open or close according to the ring network circuit data and the tripping signal; the lightning arrester is used to perform overvoltage protection; the switch device is used to construct and eliminate breakpoints and bear the corresponding voltage difference. By installing the ring network controller of this solution in the ring network circuit, it can be achieved that when the line is switched, the ring is closed first and then opened. The switch device constructs the breakpoint when closing the ring and eliminates the breakpoint when opening the ring, effectively eliminating the closing impact current generated by the ring network circuit, solving the power outage problem in the process of transferring line loads due to reasons such as line maintenance, and improving the power supply reliability of important loads.

[0070] The ring network controller in this solution has a simple structure, including only lightning arresters, switchgear, control equipment and communication equipment, and requires little change to the distribution network. It has the advantages of low cost and simple operating principle. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 This is a structural effect diagram of a ring network controller containing communication equipment of the present invention;

[0072] Figure 2 This is a schematic diagram of the installation of the ring network controller in a single ring network in the present invention;

[0073] Figure 3 This is a schematic diagram of the installation of the ring network controller in the double ring network of the present invention;

[0074] Figure 4 This is a schematic diagram of the installation of the ring network controller in the N supply-one standby wiring of the present invention. DETAILED DESCRIPTION

[0075] In order to better understand the present invention, the present invention is further described below with reference to the accompanying drawings and examples.

[0076] Example 1:

[0077] This embodiment provides a ring network controller including communication equipment, the structure effect diagram is as follows Figure 1 shown.

[0078] A ring network controller consists of lightning arresters, power electronic devices, mechanical switches, control equipment and communication equipment, which are connected in series in the line.

[0079] The switches in the ring network controller can be conventional switches with contacts, or power electronic devices, or both in series or in parallel. Alternatively, conventional switches can be connected in series with resistive and inductive elements, or power electronic devices can be connected in series with resistive and inductive elements, or both in parallel. The power electronic devices in this embodiment can be thyristors or other devices. The mechanical switches and thyristors function to create and eliminate breakpoints, and to bear the corresponding voltage differences.

[0080] The thyristor should be able to withstand the line short-circuit impact current.

[0081] The mechanical switch should be able to withstand the line short-circuit impact current, and the terminal withstand voltage level of the mechanical switch may not be equal to its insulation voltage level to ground.

[0082] The control device in this embodiment includes a measuring module and a control module. The measuring module can use a conventional mutual inductor or sensor to measure the voltage difference U2 across the ring network controller. For determining the instantaneous voltage difference across the ring network controller, a breakdown diode BOD can also be used. The breakdown voltage of the BOD is equal to the set value U of the voltage difference U2 across the ring network controller. thr Therefore, when BOD breaks down, it can be considered that U2 exceeds the set value U thr The control module is used to control the opening and closing of the mechanical switch and the cutoff and triggering of the thyristor according to the control signal.

[0083] The arrester in the ring network controller can be a metal oxide arrester or a valve type arrester, or a metal oxide arrester in series with a resistive inductive element, or a valve type arrester in series with a resistive inductive element. Its continuous operating voltage should be greater than the maximum break voltage that would occur at the ring network controller installation location during steady-state operation to ensure normal operation of the ring network controller during normal parallel and parallel operation.

[0084] The communication equipment is used to receive the opening signal generated by the ring network circuit when it is closed. It is an analog or digital signal obtained from a remote location.

[0085] When the ring network is closed, the communication device in the ring network controller receives the trip signal, and the ring network controller switches to the thyristor off state and the mechanical switch off state. This switching process is as follows: the thyristor is triggered first, then the mechanical switch is opened. After the mechanical switch is opened, the thyristor triggering stops after a delay.

[0086] When the ring network is unhooked at the target location, the ring network controller switches to the thyristor-off state and the mechanical switch-on state by determining the instantaneous voltage difference. This switching process can be as follows: the thyristor is triggered first, then the mechanical switch is closed. After the mechanical switch is closed, the thyristor triggering is stopped for a period of time. If the mechanical switch is activated quickly enough, this switching process can also be as follows: the mechanical switch is closed directly.

[0087] Example 2:

[0088] This embodiment provides a control method for a ring network controller including a communication device. The ring network controller can assist in power outage and de-energization operations. The specific contents are as follows:

[0089] The ring network controller collects the instantaneous voltage difference U2 at both ends.

[0090] A single ring network controller is installed within a ring network. If a closing surge current is generated during line closing, the ring network controller activates, causing a break at the controller's location. The ring network is temporarily unhooked at the controller's location, with the power supplies on both sides independently supplying power to their connected loads. Once the ring network line is unhooked at the target unhooking location, the ring network controller will no longer be in a break state according to pre-set control logic.

[0091] When the ring network circuit is closed, the opening signal sent by the remote party and the instantaneous value of the voltage difference U2 at both ends of the ring network controller are used as input quantities, and U thr As the set value, U2 and U thr Comparison is made to determine whether to output a trigger signal to the thyristor and whether to output a gate-opening signal to the mechanical switch.

[0092] If there is a trip signal and U2<U thr , the opening is executed: the opening command is sent to the mechanical switch. After a delay t1, the trigger command is sent to the thyristor. After the delay t2 is reached, the thyristor is stopped from being triggered.

[0093] If U2 ≥ U thr , then execute closing: if it is already closed, keep closing; if it is originally in the open state, execute closing, immediately send thyristor triggering signal and mechanical switch closing command, thyristor triggering first, then mechanical switch closing, after mechanical switch closing, stop triggering thyristor after a delay t3.

[0094] The time required for the trip signal to be generated, transmitted, received, and completed by the switchgear should ensure that the fastest-acting overcurrent protection in the line is not activated. If the line lacks overcurrent protection, the switch opening time should also be less than 0.3s. The switch closing time should be less than 10ms to ensure that no power quality issues occur on the line. The switch can operate independently of the three phases or in a coordinated manner.

[0095] When the ring network controller collects the voltage difference between its two ends, it can be obtained by measuring the instantaneous value of the voltage difference between the two ends of the ring network controller, or by measuring the instantaneous voltage values ​​on the bus side and the line side of the ring network controller and then subtracting them. To ensure that there are no power quality problems on the measurement line, this measurement delay should be less than 10ms.

[0096] Example 3:

[0097] This embodiment provides a wiring method for a ring network controller including communication equipment.

[0098] One device needs to be installed in a ring network and can be located at any position in the ring network.

[0099] The installation locations in a ring network include: inside the substation where the busbar comes out; on the low-voltage side of the first box-type transformer after the busbar comes out; inside or next to a ring network cabinet; on any line in the ring network.

[0100] In a single ring network, there is only one ring network, such as Figure 2 As shown in , therefore, at any position between the busbar outlets on both sides of the single ring network, that is, Figure 2 A ring network controller with communication can be installed in the circled area. It can be installed in: the substation where the busbar is connected, the low-voltage side of the first box-type transformer after the busbar is connected, inside or next to a ring network cabinet, or on a certain line.

[0101] In the double ring network connection distribution network, it is necessary to Figure 3 Multiple ring network controllers are installed within the dual-ring network shown. Specifically, two are installed at positions 1 and 4, or two are installed at positions 2 and 3. This ensures that all rings that may be formed due to changes in switch states have ring network controllers. For example, when load 1 needs to switch from substation A to substation C, the ring can be closed directly at point 1 within the dual-ring network, with the ring network controller at position 1 assisting in the closing and unclosing operation. When load 1 needs to switch from substation C to substation D, load switch B between load 1 and substation D is closed. After closing, substations C and D form a closed ring. If a closing shock occurs, the ring network controller at position 4 in this ring network will operate normally to assist in the closing and unclosing operation. Positions 1-4 can be: within the substation at the busbar outlet, on the low-voltage side of the first box-type transformer after the busbar outlet, on the line between the busbar outlet and the first ring main unit, or inside or next to the first ring main unit after the busbar outlet.

[0102] In the N-supply-one-backup wiring distribution network, the only time the backup power supply is put into operation is when the loop may be closed and disconnected. Figure 4 In the N-supply, one-backup wiring distribution network shown, a ring network controller can be installed anywhere in the circled area. This includes: the substation where the backup bus exits, the low-voltage side of the first box-type transformer after the backup bus exits, a certain line after the backup bus exits, and inside or near the ring network cabinet where the normally closed contacts connecting the backup bus and the power supply bus are located.

[0103] In this installation method, the arrester, thyristor, mechanical switch, control module, measurement module, and communication equipment are all fixed. Part of the arrester, thyristor, mechanical switch, control module, and measurement module can be fixed. The rest of the control module, measurement module, and communication equipment are movable. When parallel operation is required, the movable part is connected to the fixed part.

[0104] If there is a switch device in the ring network that can be used in parallel with the ring network controller and can be used to bypass and put the bypass ring network controller into operation, the entire ring network controller can be used as a mobile device and can be moved to the switch position for use when needed.

[0105] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0106] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0107] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0108] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0109] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0110] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A control method for a ring network controller including a communication device, characterized in that: include When the ring network circuit is closed, the ring network controller receives a tripping signal through a communication device, collects a voltage instantaneous difference through a measurement module, and the control device in the ring network controller controls the switch device in the ring network controller to configure a breakpoint according to the tripping signal and the voltage instantaneous difference, thereby eliminating the closing impact in the ring network circuit, specifically including: When the ring network circuit is closed, if the instantaneous voltage difference across the ring network controller is less than a set threshold and the communication device receives a trip signal, the measurement module generates a trip instruction; otherwise, no trip instruction is generated and the current state of the mechanical switch in the ring network control is maintained; The control device controls the switch device to construct a breakpoint according to the opening instruction, thereby eliminating the closing impact in the ring network circuit; The time from the generation of the trip signal, the transmission of the trip signal, the reception of the trip signal to the completion of the tripping action of the switching device should ensure that the fastest-acting line overcurrent protection in the line does not operate; When the ring network circuit is unhooked, the control device controls the switch device to eliminate the breakpoint, bypass the lightning arrester, and restore the voltage of the ring network circuit; The ring network controller containing the communication equipment specifically includes: Lightning arresters, switchgear, control equipment and communications equipment; The lightning arrester is connected in parallel with the switchgear; The communication device is connected to the control device and is used to receive in real time the opening signal generated when the ring network circuit is closed; The control device is connected to the switch device and is used to collect ring network circuit data and control the switch device to open or close according to the ring network circuit data and the received opening signal; The lightning arrester is used for overvoltage protection; The switching device is used to construct and eliminate breakpoints and bear the corresponding voltage differences.

2. The method according to claim 1, wherein The switch device may be one or more of a mechanical switch and a power electronic device.

3. The method according to claim 2, wherein The switch device comprises: Mechanical switches and power electronics; The mechanical switch and power electronic device are connected in series or in parallel and then connected in parallel with the lightning arrester; The mechanical switch and the power electronic device are also connected to the control device.

4. The method according to claim 1, wherein The switching device may be one or more of a mechanical switch connected in series with a resistive-inductive element or a power electronic device connected in series with a resistive-inductive element.

5. The method according to claim 4, wherein The switch device comprises: Mechanical switches with series resistance and inductive elements and power electronic devices with series resistance and inductive elements; The mechanical switch of the series resistive-inductive element is connected in parallel with the power electronic device of the series resistive-inductive element and then connected in parallel with the lightning arrester; The mechanical switch of the series-connected resistive-inductive element and the power electronic device of the series-connected resistive-inductive element are connected to the control device.

6. The method according to claim 2 or 4, wherein: The power electronic device should be able to withstand the short-circuit impact current of the ring network circuit.

7. The method according to claim 2 or 4, wherein: The mechanical switch should be able to withstand the short-circuit impact current of the ring network circuit, and the terminal withstand voltage level of the mechanical switch is not equal to the insulation voltage level of the mechanical switch to ground; The mechanical switch can operate in three phases separately or in a three-phase linkage manner.

8. The method according to claim 1, wherein The arrester may be a metal oxide arrester, a valve type arrester, a metal oxide arrester in series with a resistive and inductive element, or a valve type arrester in series with a resistive and inductive element; The continuous operating voltage of the lightning arrester should be greater than the maximum break voltage that occurs at the installation location of the ring network controller during steady-state operation.

9. The method according to claim 3, wherein The control device comprises: Interconnected measurement modules and control modules; The control module is connected to the mechanical switch and the power electronic device; The measuring module is used to collect the instantaneous voltage difference at both ends of the ring network controller, and formulate an opening instruction or a closing instruction according to the instantaneous voltage difference at both ends of the ring network controller and the received opening signal; The control module is used to control the mechanical switch to be disconnected or closed according to the opening instruction or the closing instruction.

10. The method according to claim 9, wherein The measuring module may be a conventional mutual inductor or sensor.

11. The method according to claim 9, wherein The measuring module uses a breakdown diode BOD to determine the instantaneous difference in measured voltage; The breakdown diode BOD is connected in parallel at both ends of the ring network controller; The breakdown voltage of the breakdown diode BOD is equal to the set voltage difference instantaneous threshold.

12. The method according to claim 1, wherein The control device may be a device that takes energy from voltage and supplies energy.

13. The method according to claim 9, wherein The lightning arrester, power electronic device, mechanical switch, measurement module, control module and communication equipment are fixedly installed in the ring network circuit.

14. The method according to claim 9, wherein The lightning arrester, power electronic device and mechanical switch are fixedly installed in the ring network circuit; When the ring network circuit is closed or opened, the measuring module, the control module and the communication device are connected to the lightning arrester, the power electronic device and the mechanical switch as the moving parts.

15. The method according to claim 9, wherein When there is a switching device in the ring network circuit that can be used in parallel with the ring network controller, the lightning arrester, power electronic device, mechanical switch, measurement module, control module and communication equipment can be connected as mobile parts to the switching device that can be used in parallel with the ring network controller to perform ring closing and ring opening operations.

16. The method according to claim 1, wherein When the ring network circuit is a distribution network with single ring network connection, one ring network controller is installed in the ring network circuit; When the ring network circuit is a double-ring network connection distribution network, two ring network controllers are installed in the ring network circuit; When the ring network circuit is an N-1 wiring distribution network, one ring network controller is installed in the spare bus.

17. The method according to claim 1, wherein The control device controls the switch device to configure a breakpoint according to the opening instruction, including: The control device controls the mechanical switch in the switch device to open according to the opening instruction, triggers the power electronic device in the switch device after a first set delay, and cuts off the power electronic device after a second set delay; When the first set delay is reached, the mechanical switch has not yet started to open; When the second set delay is reached, the mechanical switch has been opened and the arc has been extinguished.

18. The method according to claim 1, wherein When the ring network circuit is unhooked, the control device controls the switch device to eliminate the breakpoint, bypass the lightning arrester, and restore the voltage of the ring network circuit, including: The measurement module in the control device collects the instantaneous voltage difference between the two ends of the ring network controller; When the ring network circuit is unlocked, if the instantaneous voltage difference across the ring network controller is greater than a set threshold, the measurement module generates a closing instruction; otherwise, no closing instruction is generated, and the current state of the mechanical switch in the ring network control is maintained; The control device controls the switch device to eliminate the breakpoint, bypass the lightning arrester, and restore the ring network circuit voltage according to the closing instruction; The time from the moment the instantaneous voltage difference at both ends of the ring network controller exceeds the threshold to the completion of closing should be within 10 ms.

19. The method according to claim 9, wherein The control module controls the switch device to eliminate the breakpoint according to the closing instruction, including: The control module controls the triggering of the power electronic device and the closing of the mechanical switch in the switch device according to the closing instruction, and cuts off the power electronic device after a third set delay; When the third set delay is reached, the mechanical switch completes closing and carries the load current.

20. The method according to claim 19, wherein The control module controls the switch device to eliminate the breakpoint according to the closing instruction, including: If the mechanical switch is in the closed state, the control module controls the mechanical switch in the switch device to maintain the closed state according to the closing instruction.

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