阅读说明：本技术 基于5g网络的配网区域拓扑识别方法及系统 (Distribution network area topology identification method and system based on 5G network ) 是由 周可慧 唐海国 张帝 朱吉然 李红青 任磊 游金梁 康童 邓威 刘奕 周恒逸 于 2021-07-29 设计创作，主要内容包括：本发明公开了基于5G网络的配网区域拓扑识别方法及系统,通过为配网区域的DTU配置5G模组,使配网区域的DTU通过5G模组接入配网区域对应的本地5G核心网,以构建配网区域的5G网络；将配网区域内的带有联络点开关的DTU设为主机,将配网区域内不带有联络点开关的DTU设为从机,并分别为配网区域的每台DTU设置唯一编号信息,并在主机的编号信息中添加主机标识；配网区域的各个DTU对等通信,并通过各自的5G模组将各自的编号信息/接收到的其他DTU的编号信息传送给相邻两侧的DTU,以使得主机通过5G通信网络收集各个DTU的编号信息,从而快速识别出该配网区域的拓扑,实现配网区域的拓扑的自动识别。(The invention discloses a distribution network area topology identification method and a distribution network area topology identification system based on a 5G network, wherein a 5G module is configured for a DTU of a distribution network area, so that the DTU of the distribution network area is accessed to a local 5G core network corresponding to the distribution network area through the 5G module to construct the 5G network of the distribution network area; setting a DTU with a contact point switch in a distribution network area as a host, setting a DTU without the contact point switch in the distribution network area as a slave, respectively setting unique serial number information for each DTU in the distribution network area, and adding a host identifier in the serial number information of the host; each DTU in the distribution network area communicates peer to peer, and the respective number information/the received number information of other DTUs is transmitted to the DTUs on the two adjacent sides through the respective 5G module, so that the host computer collects the number information of each DTU through the 5G communication network, the topology of the distribution network area is rapidly identified, and the automatic identification of the topology of the distribution network area is realized.)

1. A distribution network area topology identification method based on a 5G network is characterized by comprising the following steps:

configuring a 5G module for a DTU of a distribution network area, and enabling the DTU of the distribution network area to be accessed to a local 5G core network corresponding to the distribution network area through the 5G module to construct a 5G network of the distribution network area;

setting a DTU with a contact point switch in the distribution network area as a host, setting a DTU without the contact point switch in the distribution network area as a slave, setting unique serial number information for each DTU in the distribution network area respectively, and adding a host identifier in the serial number information of the host;

and each DTU in the distribution network area communicates peer to peer, and transmits the respective number information/the received number information of other DTUs to the DTUs on two adjacent sides through the respective 5G module, so that the host collects the number information of each DTU through the 5G communication network to identify the topology of the distribution network area.

2. The distribution network area topology identification method based on the 5G network, according to claim 1, wherein the distribution network area is a two-power-one-contact-point line system, the host collects basic information of each DTU through the 5G communication network to identify the topology of the distribution network area, and specifically includes the following steps:

all DTUs in the distribution network area carry out point-to-point communication with adjacent DTUs through respective 5G modules, and the communication content is own serial number information, wherein the DTUs of the ring net cage directly connected with the power supply receive the serial number information of the DTUs on one side adjacent to the DTUs, and other DTUs receive the serial number information of the DTUs on two sides adjacent to the DTUs;

giving a piece of search information, determining a DTU1 of the ring net cage directly connected with a power source according to the number of the types of the serial number information received by each DTU, controlling the DTU1 to send the serial number information of the DTU1 to the DTU2 on the adjacent side of the DTU, controlling the DTU2 to send the serial number information of the DTU2 and the received serial number information to the DTU3 adjacent to the DTU, controlling the DTU3 to send the serial number information of the DTU2 and the received serial number information of the DTU4 adjacent to the DTU, and repeating the steps until a host DTU with mark information is searched, stopping searching, and sequentially transmitting the serial number information of all the DTUs of the main line to the host DTU according to the sequence close to the power source point so that the host DTU can sense the static topology of the whole line.

3. The distribution network area topology identification method based on the 5G network, according to claim 2, wherein the number information includes IP addresses and positions of DTUs and numbers of corresponding ring net cages, for any DTU, the upstream-downstream relationship of a trunk switch corresponding to the DTU is determined through the relative position relationship between the DTU and a power supply point and a contact point, for any node, one side of the two side nodes close to the power supply point is determined as an upstream side, and one side of the two side nodes close to an open loop point is determined as a downstream side.

4. The distribution network area topology identification method based on the 5G network according to claim 1, wherein a trunk line of the distribution network area adopts longitudinal differential protection, topology identification is assisted, a bus adopts bus differential protection, and a branch line adopts overcurrent protection.

5. The distribution network area topology identification method based on the 5G network according to claim 1, further comprising the following steps:

the 5G network of the distribution network area adopts a 5G LAN mode, sinks to the edge of the 5G network of the distribution network area through the UPF equipment, enables the DTU equipment close to the electricity user to complete the corresponding LAN SWITCH function, and saves the transmission and exchange time delay above a convergence layer.

6. The distribution network area topology identification method based on the 5G network, according to claim 5, further comprising the steps of:

when the power distribution area is monitored to have a line fault, the fault area is located, switches on two adjacent sides of the fault area are tripped, a switching signal is sent to a contact point, the contact point receives the switching signal, and switching actions are executed according to the switching signal: and delaying switching on, and recovering the power supply of the fault area.

7. The method for identifying the distribution network area topology based on the 5G network as claimed in claim 6, wherein the contact point must satisfy the following conditions at the same time, and after a certain delay, the transfer action can be executed:

A. the circuit breaker of the circuit where the contact point is located has no abnormity, has only one open loop point, and has no maintenance switch;

B. the line where the contact point is located is in normal communication;

C. the contact point switch is positioned in a position division;

D. both sides of an open loop point corresponding to the contact point are provided with pressure;

E. the contact point does not satisfy the discharge condition.

8. The method for identifying the distribution network area topology based on the 5G network according to claim 7, wherein the contact point stops forwarding when any of the following conditions exist:

1) exiting the distributed FA corresponding to the contact point;

2) the open loop point corresponding to the contact point does not have a closing condition;

3) both sides of an open loop point corresponding to the contact point are free of pressure and are delayed for a period of time;

4) the bus protection action or failure protection action of the ring net cage where the open-loop point corresponding to the contact point is located;

5) and (5) power supply recovery action of the fault area.

9. The distribution network area topology identification method based on the 5G network, according to claim 8, is characterized in that after the distribution network area is put into the distributed FA, and a switch in the distribution network area meets a switching-off condition, and does not act after the failure judgment time, when a switch operation rejection signal is sent out, a failure protection action is started, and a switch at the previous stage of the switch operation rejection signal is switched off.

10. A computer system comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the steps of the method of any one of claims 1 to 9 are performed when the computer program is executed by the processor.

Technical Field

The invention relates to the field of distribution automation, in particular to a distribution network area topology identification method and system based on a 5G network.

Background

As the urban power consumption continuously increases, the requirements on power supply reliability, power quality, service level and the like are continuously improved; meanwhile, the distributed energy resources are used for surfing the internet, the flexible load is increased, the requirements of electric automobile application and the like on the stability of the operation of the power distribution network are higher and higher, and faults cannot be rapidly and effectively processed through the traditional power distribution network. The 5G communication technology solves the problem of 'interconnection between objects', has the technical characteristics of high speed, ubiquitous network, low power consumption and low time delay, can meet the requirements of power service, and expands the application scene of wireless communication in a distribution network.

Topology automatic identification is an important measure for improving distribution automation, and at present, topology identification mainly depends on a distribution automation master station system, how to solve the topology identification problem through 5G network application and based on terminal communication becomes a technical problem to be solved urgently in the field.

Disclosure of Invention

The invention provides a distribution network area topology identification method and a distribution network area topology identification system based on a 5G network, which are used for realizing topology identification based on terminal communication by utilizing the 5G network.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a distribution network area topology identification method based on a 5G network comprises the following steps:

configuring a 5G module for the DTU of the distribution network area, and enabling the DTU of the distribution network area to be accessed to a local 5G core network corresponding to the distribution network area through the 5G module to construct a 5G network of the distribution network area;

setting a DTU with a contact point switch in a distribution network area as a host, setting a DTU without the contact point switch in the distribution network area as a slave, respectively setting unique serial number information for each DTU in the distribution network area, and adding a host identifier in the serial number information of the host;

and each DTU in the distribution network area communicates peer to peer, and the respective number information/the received number information of other DTUs is transmitted to the DTUs on two adjacent sides through the respective 5G module, so that the host collects the number information of each DTU through the 5G communication network to identify the topology of the distribution network area.

Preferably, the distribution network area is a two-power-one-contact-point line system, and the host collects basic information of each DTU through a 5G communication network to identify the topology of the distribution network area, which specifically comprises the following steps:

all DTUs in the distribution network area carry out point-to-point communication with adjacent DTUs through respective 5G modules, and the communication content is own serial number information, wherein the DTUs of the ring net cage directly connected with the power supply receive the serial number information of the DTUs on one side adjacent to the DTUs, and other DTUs receive the serial number information of the DTUs on two sides adjacent to the DTUs;

giving a piece of search information, determining a DTU1 of the ring net cage directly connected with a power source according to the number of the types of the serial number information received by each DTU, controlling the DTU1 to send the serial number information of the DTU1 to the DTU2 on the adjacent side of the DTU, controlling the DTU2 to send the serial number information of the DTU2 and the received serial number information to the DTU3 adjacent to the DTU, controlling the DTU32 to send the serial number information of the DTU2 and the received serial number information of the DTU4 adjacent to the DTU, and repeating the steps until a host DTU with mark information is searched, stopping searching, and sequentially transmitting the serial number information of all the DTUs of the main line to the host DTU according to the sequence close to the power source point so that the host DTU can sense the static topology of the whole line.

Preferably, the serial number information includes an IP address and a location of the DTU and a serial number corresponding to the ring net cage, and for any DTU, the upstream-downstream relationship of the trunk switch corresponding to the DTU is determined according to the relative positional relationship between the DTU and the power supply point and the contact point, and for any node, one side of the two side nodes close to the power supply point is determined as an upstream, and one side close to the ring opening point is determined as a downstream.

Preferably, the trunk line of the distribution network area adopts pilot differential protection assisted by topology identification, the bus adopts bus differential protection, and the branch line adopts overcurrent protection.

Preferably, the method further comprises the following steps:

the 5G network of the distribution network area adopts a 5G LAN mode, sinks to the edge of the 5G network of the distribution network area through the UPF equipment, enables the DTU equipment close to the electricity user to complete the corresponding LAN SWITCH function, and saves the transmission and exchange time delay above the convergence layer.

Preferably, the method further comprises the following steps:

when it is monitored that a line in a power distribution area has a fault, the fault area is positioned, switches on two adjacent sides of the fault area are tripped and send a switching signal to a contact point, and the contact point receives the switching signal and executes a switching action according to the switching signal: and delaying switching on, and recovering the power supply of the fault area.

Preferably, the contact point must satisfy the following conditions at the same time, and after a certain delay, the transfer action can be executed:

A. the circuit breaker of the circuit where the contact point is located has no abnormity, has only one open loop point, and has no maintenance switch;

B. the line where the contact point is located is in normal communication;

C. the contact point switch is positioned in the position division;

D. both sides of an open loop point corresponding to the contact point are provided with pressure;

E. the contact point does not satisfy the discharge condition.

Preferably, the contact point ceases spinning when any of the following conditions exist:

1) exiting the distributed FA corresponding to the contact point;

2) the open loop point corresponding to the contact point does not have a closing condition;

3) both sides of an open loop point corresponding to the contact point are pressureless and delayed for a period of time;

4) protecting or failure protecting the ring net cage bus where the open-loop point corresponding to the contact point is located;

5) and (5) power supply recovery action of the fault area.

Preferably, after the distribution network area is fed with the distributed FA, and the switch in the distribution network area meets the switching-off condition, the switch does not act after the failure judgment time, and when the switch refusing signal is sent, the failure protection action is started, and the switch at the upper stage of the switch is refused to be switched off.

A computer system comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the steps of the method being performed when the computer program is executed by the processor.

The invention has the following beneficial effects:

1. according to the method and the system for identifying the topology of the distribution network area based on the 5G network, the 5G module is configured for the DTU of the distribution network area, so that the DTU of the distribution network area is accessed to the local 5G core network corresponding to the distribution network area through the 5G module to construct the 5G network of the distribution network area; setting a DTU with a contact point switch in a distribution network area as a host, setting a DTU without the contact point switch in the distribution network area as a slave, respectively setting unique serial number information for each DTU in the distribution network area, and adding a host identifier in the serial number information of the host; each DTU in the distribution network area communicates peer to peer, and the respective number information/the received number information of other DTUs is transmitted to the DTUs on the two adjacent sides through the respective 5G module, so that the host computer collects the number information of each DTU through the 5G communication network, topology identification does not need to depend on a master station system, the topology of the whole line can be obtained through mutual communication between terminals, the topology of the distribution network area is quickly identified, and automatic identification of the topology of the distribution network area is realized.

2. In a preferred scheme, the method focuses on the core area of the urban distribution network, organically combines the area protection control technology, the communication technology and the distribution automation, realizes automatic circuit topology identification, quickly positions and isolates a fault section and transfers power to a non-fault area for power restoration, greatly shortens the fault power failure time and improves the operation efficiency of the distribution network.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic diagram of a 5G network-based line topology in a preferred embodiment of the present invention, in which (a) is a main line fault, (b) is a bus line fault, and (c) is a branch line fault;

FIG. 2 is a schematic diagram of a topology identification method in a preferred embodiment of the present invention;

fig. 3 is a flowchart of a distribution network area topology identification method based on a 5G network.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

The first embodiment is as follows:

as shown in fig. 3, the invention discloses a distribution network area topology identification method based on a 5G network, which comprises the following steps:

configuring a 5G module for the DTU of the distribution network area, and enabling the DTU of the distribution network area to be accessed to a local 5G core network corresponding to the distribution network area through the 5G module to construct a 5G network of the distribution network area;

setting a DTU with a contact point switch in a distribution network area as a host, setting a DTU without the contact point switch in the distribution network area as a slave, respectively setting unique serial number information for each DTU in the distribution network area, and adding a host identifier in the serial number information of the host;

and each DTU in the distribution network area communicates peer to peer, and the respective number information/the received number information of other DTUs is transmitted to the DTUs on two adjacent sides through the respective 5G module, so that the host collects the number information of each DTU through the 5G communication network to identify the topology of the distribution network area.

In addition, in this embodiment, the present invention also discloses a computer system, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the method are implemented.

According to the method and the system for identifying the topology of the distribution network area based on the 5G network, the 5G module is configured for the DTU of the distribution network area, so that the DTU of the distribution network area is accessed to the local 5G core network corresponding to the distribution network area through the 5G module to construct the 5G network of the distribution network area; setting a DTU with a contact point switch in a distribution network area as a host, setting a DTU without the contact point switch in the distribution network area as a slave, respectively setting unique serial number information for each DTU in the distribution network area, and adding a host identifier in the serial number information of the host; each DTU in the distribution network area communicates peer to peer, and the respective number information/the received number information of other DTUs is transmitted to the DTUs on the two adjacent sides through the respective 5G module, so that the host computer collects the number information of each DTU through the 5G communication network, the topology of the distribution network area is rapidly identified, and the automatic identification of the topology of the distribution network area is realized.

Example two:

the second embodiment is an extended embodiment of the first embodiment, and is different from the first embodiment in that the distribution network region topology identification method is refined:

in the embodiment, a distribution network area topology identification method based on a 5G network is disclosed, which includes: aiming at a two-power-one-contact-point line system, a master-slave structure is adopted, a DTU with a contact point switch is set as a host, peer-to-peer communication between nodes is established based on a 5G network, a topological system is automatically identified through serial number information of each DTU, and when a fault occurs in a corresponding area, a distribution network area protection system can perform comprehensive judgment and decision according to a formulated strategy to realize the functions of fault positioning, isolation and power restoration, and the method specifically comprises the following contents:

A5G wireless module is installed on a DTU, a local core network is accessed through a carrying network and a transmission network to realize base station intercommunication, a hand-in-hand networking mode is adopted, namely information of the node is transmitted to nodes on two adjacent sides through 5G front-end equipment, then the information is gradually accumulated to a host, and the whole network information is collected by a host device. By adopting a 5G LAN mode, a UPF (User Plane Function) device is an important component of a 3GPP 5G core network system architecture and is mainly responsible for routing and forwarding related functions of a 5G core network User Plane data packet to sink to the edge of a network, is close to a terminal device of a client and completes a corresponding LAN SWITCH (switching) Function, and transmission and switching time delay above a convergence layer is saved; and aiming at different types of faults, adopting corresponding fault processing strategies. The trunk line adopts longitudinal differential protection assisted by topology identification, the bus adopts bus differential protection, and the branch line adopts overcurrent protection.

The topology identification method comprises the following main steps:

(1) each DTU of the trunk line sets unique number information, and the number of the DTU of the host adds a piece of mark information to distinguish the slave machines.

(2) Collecting numbering information for the first time: all DTUs carry out point-to-point communication through wireless module each other, and the looped netowrk case DTU with power lug connection receives the DTU serial number information of one side, and other DTUs receive the DTU serial number information of adjacent both sides.

(3) Collecting the number information for the second time: given a search signal, the DTU-1 receiving only one-side number information is searched, and the DTU-1 number is transferred to the DTU-2 receiving the number. The DTU-2 compares the number information received twice, and transfers the number information collected for the second time (DTU-1 and DTU-2) to the DTU-3 which collects the number information for the first time but does not collect the number information for the second time.

(4) By analogy, the DTU-3 transfers the number information (DTU-1, DTU-2, DTU-3) collected for the second time to the DTU-4 which is collected for the first time but not collected for the second time.

(5) And when the host DTU with the mark information is searched, stopping searching, sequentially transmitting the serial number information of all the DTUs of the trunk line to the host DTU according to the sequence close to the power point, and obtaining the static topology of the whole line by the host DTU.

(6) Dynamic topology identification: for any one of the nodes, one side of the nodes on two sides close to the power supply point is determined as upstream, and one side close to the open loop point is determined as downstream.

The 5G network communication is accessed to a local core network through a carrying network and a transmission network to realize base station intercommunication, a hand-in-hand networking mode is adopted, namely, information of the node is transmitted to nodes on two adjacent sides through 5G front-end equipment, the information is gradually accumulated to a host, and the host device collects the whole network information.

And aiming at different types of faults, adopting corresponding fault processing strategies. The trunk line adopts longitudinal differential protection assisted by topology identification, the bus adopts bus differential protection, and the branch line adopts overcurrent protection.

The host collects all nodes through a communication network, and identifies the static topology of the area, so that the positions of the contact points and the power supply points, the serial numbers of all ring main units and IP information of all ring main units are obtained. In the dynamic topology identification, for any one node, the side close to the power supply point in the nodes on two sides is determined as the upstream, and the side close to the open loop point is determined as the downstream.

When a line breaks down, a fault processing strategy is adopted, a fault area is positioned, switches on two adjacent sides of the fault area are tripped, a corresponding processing signal is received by a contact point, closing is delayed, and power supply of the fault area is recovered.

In order to ensure the stability of the system operation, the contact point action needs to satisfy the following conditions:

(1) the preconditions are as follows: the circuit breaker has no abnormity, only has one open loop point and has no maintenance switch.

(2) Judging conditions: only if the following conditions are met and a certain delay is passed, the switch is judged as a contact point.

1) The line communication is normal;

2) the node switch is positioned in a position division state;

3) both sides of the open loop point are provided with pressure;

4) the discharge condition is not satisfied;

(3) discharge conditions: when any of the following conditions is satisfied, the transient discharge is supplied, and the transient discharge does not satisfy the transient supply condition.

1) Exiting the distributed FA;

2) the open loop point does not have a closing condition: the spring does not store energy, open and close actions, control loop disconnection and the like;

3) both sides of the ring opening point are pressureless and are delayed for a period of time;

4) protecting or preventing failure of the ring net cage bus at the ring opening point;

5) a power supply recovery action;

in the preferred scheme, after the distributed FA is put into use, the switch meets the brake-separating condition, does not act after the failure judgment time, sends out a switch refusing signal, starts the failure protection action, and refuses the upper-stage switch of the switch to separate.

EXAMPLE III

In this embodiment, a line topology diagram shown in fig. 1 is taken as an embodiment to describe the automatic identification of the distribution network area topology based on the 5G network and the construction of the protection system thereof.

As shown in fig. 1, a hand-in-hand mode line topology diagram is established, peer-to-peer communication among nodes is established by adopting a 5G network, a loop network box DTU No. 3 is used as a host, other loop network boxes are used as slave machines, a switch 5 is set as a contact point, a trunk line is configured with longitudinal differential protection, topology protection, bus configuration bus differential protection and branch line overcurrent protection.

(1)5G network communication

And installing a 5G wireless module in the DTU, adopting a 5G LAN mode, performing point-to-point communication, sinking to the edge of the network through UPF equipment, approaching to the terminal equipment of a client and completing the corresponding LAN SWITCH functions. The information of the node is transmitted to the nodes on two adjacent sides through the 5G front-end equipment, then the information is gradually accumulated to the host, and the host device collects the whole network information. The time delay of the point-to-point communication mainly comprises terminal uplink time delay, network side time delay (UPF exchange time delay) and terminal downlink time delay, and the time delay is about 15-20 ms.

(2) Topology automatic identification

As shown in fig. 2, each ring net cage DTU is provided with a serial number, and a flag bit is added to the serial number information of the master DTU to distinguish the slaves.

The first DTU number collection result is:

no. 1 looped netowrk case: receiving the information of the ring net cage and the ring net cage No. 2 DTU (DTU1, DTU 2);

ring main unit No. 2: receiving the information of the ring net cage itself and the information of the ring net cages No. 1 and No. 3 (DTU1, DTU2 and DTU 3);

no. 3 looped netowrk case: receiving the information of the ring net cage per se and No. 2 and No. 4 ring net cage DTU information (DTU2, DTU3 and DTU 4);

no. 4 looped netowrk case: receiving the information of the ring net cage and the ring net cage No. 3 DTU (DTU3, DTU 4);

and collecting the serial numbers of the DTUs for the second time:

searching for DTUs (DTU1, DTU4) which only receive the DTU number information of the ring net cage on one side;

the ring main unit No. 1 transmits the DTU information to the ring main unit No. 2 which can receive the information, and at the moment, the DTU information collected by the ring main unit No. 2 is DTU1 and DTU 2;

the ring network box No. 2 transmits the DTU information to the ring network box No. 3 which can receive the information and collects the DTU which does not receive the signal by numbering the DTU for the second time, at the moment, the DTU information collected by the ring network box No. 3 is DTU1, DTU2, DTU3 and the DTU of the ring network box No. 3 are hosts, and the search is stopped;

similarly, the information of the ring network unit No. 4 DTU can be collected by the ring network unit No. 3, the collected information is integrated to obtain the topological relation of the trunk line, and the upstream and downstream relation of the trunk line switch is determined by the relative position relation between the power supply point and the contact point.

(3) Fault handling

Main line fault:

as shown in fig. 1 (a), if a bus between the ring net cage No. 1 and the ring net cage No. 2 has a fault, the switch 2 and the switch 3 obtain adjacent switch signals through 5G network communication, the pilot differential protection enables the switch 2 and the switch 3 to be tripped, action information is sequentially transmitted to the host, the DTU receives a fault isolation success signal, and after detecting that the voltage of one side of the contact point is lost, the contact point acts, switches on, and power supply of a non-fault area is recovered.

If the switch 2 of the ring main unit No. 1 is still not operated after the failure judgment time, the switch 2 sends a failure signal, the switch 1 receives the failure signal, the switch 2 is judged to be failed, the failure protection action is started, and the switch 1 trips. And simultaneously, signals of the switch 1 and the switch 3 are transmitted to the host, a fault isolation success signal is received, and the single-side voltage loss of the contact point and the action of the contact point are detected.

Branch line failure:

as shown in fig. 1 (b), if the branch line of the ring main unit No. 1 fails, an overcurrent signal is detected at the feeder switch 9, branch line overcurrent protection is started, the switch 9 trips, and a fault isolation success signal is transmitted to the host through the 5G network.

If the switch 9 of the ring main unit No. 1 still does not act after the failure judgment time, the switch 9 sends a failure signal, the switch 1 and the switch 2 receive the failure signal, the switch 9 is judged to be failed, the failure protection action is started, and the switch 1 and the switch 2 trip. Meanwhile, a switch action signal is transmitted to the host, the DTU receives a fault isolation success signal, and single-side voltage loss and contact point action of a contact point are detected.

And (3) bus fault:

as shown in fig. 1 (c), when the bus of the ring main unit 1 fails, a bus protection action is started, the main line switch of the ring main unit is tripped, and a fault isolation success signal is transmitted to the host, the host DTU receives the signal and detects a contact point single side, and the contact point switch is switched on.

In conclusion, the method focuses on the core area of the urban power distribution network, organically combines the area protection control technology, the communication technology and the power distribution automation, realizes automatic circuit topology identification, quickly positions and isolates the fault section, and transfers power to the non-fault area for power restoration, greatly shortens the fault power failure time, and improves the operation efficiency of the power distribution network.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.