CN113054631A

CN113054631A - Power distribution network fault isolation self-healing system and method

Info

Publication number: CN113054631A
Application number: CN202110334465.0A
Authority: CN
Inventors: 马天祥; 范辉; 贾伯岩; 张智远; 沈宏亮; 段昕; 贾静然
Original assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Hebei Electric Power Co Ltd; State Grid Hebei Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Hebei Electric Power Co Ltd; State Grid Hebei Electric Power Co Ltd
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2021-06-29
Anticipated expiration: 2041-03-29
Also published as: CN113054631B

Abstract

The invention is suitable for the technical field of power grids, and provides a power distribution network fault isolation self-healing system and a power distribution network fault isolation self-healing method. The protection device is cooperatively matched with the self-healing terminal, so that the isolation and self-healing capacity is strong, the performance in the aspect of removal and isolation is reliable, the performance in the aspect of self-healing recovery is stable, the internal setting is easy, and the operation and maintenance difficulty is small.

Description

Power distribution network fault isolation self-healing system and method

Technical Field

The invention belongs to the technical field of power grids, and particularly relates to a fault isolation and self-healing system and method for a power distribution network.

Background

With the continuous acceleration of the urbanization process and the continuous improvement of the demand of people for highly reliable power supply, the construction of highly reliable power distribution networks becomes a necessary development trend. In the construction of a high-reliability power distribution network, a network frame is a foundation, equipment is a key, and automation is a means.

In the prior art, the fault self-healing of the power distribution network usually adopts an intelligent distributed feeder automation mode, and the self-healing process can meet the requirement of open loop switching to self-healing by acquiring multi-source information and an internal algorithm. But the performance is not good in the aspect of fault removal and isolation, the internal setting is complex, and the operation and maintenance difficulty is large.

Disclosure of Invention

In view of this, the embodiment of the invention provides a power distribution network fault isolation self-healing system and a power distribution network fault isolation self-healing method, so as to solve the problems that an intelligent distributed feeder automation mode in the prior art is poor in performance in the aspect of fault removal isolation, complex in internal setting and high in operation and maintenance difficulty.

A first aspect of an embodiment of the present invention provides a power distribution network fault isolation self-healing system, including: the system comprises four groups of transformer substations, a plurality of groups of switch stations and at least one first-type distribution room;

the multiple groups of switch stations are connected by hands in sequence; the incoming line interval of the first bus is connected with the outgoing line interval of the first group of substations, and the incoming line interval of the second bus is connected with the outgoing line interval of the second group of substations; the last group of switch stations are connected with the outgoing line intervals of the fourth group of substations at the incoming line intervals of the first bus, and the incoming line intervals of the second bus are connected with the outgoing line intervals of the third group of substations at the outgoing line intervals of the second bus;

each group of transformer substations is provided with a differential protection device;

in each group of switch stations: the first bus and the second bus are both provided with an incoming line differential protection device, an outgoing line differential protection device, a bus protection device and a self-healing terminal, and the bus coupler switch is provided with a spare power automatic switching device; the incoming line differential protection device corresponding to the first bus, the outgoing line differential protection device corresponding to the first bus and the bus protection device corresponding to the first bus are connected with the self-healing terminal corresponding to the first bus; the incoming line differential protection device corresponding to the second bus, the outgoing line differential protection device corresponding to the second bus and the bus protection device corresponding to the second bus are connected with the self-healing terminal corresponding to the second bus;

for any one first type of distribution room: in the first-class power distribution room, the incoming line interval of a first bus is connected with the feeder line interval corresponding to the first bus of a first switch station, and the incoming line interval of a second bus is connected with the feeder line interval corresponding to the second bus of the first switch station; the first switching station is any one of a plurality of groups of switching stations;

the first bus and the second bus of each first-class power distribution room are provided with incoming line differential protection devices; each first-type power distribution room is provided with a self-healing terminal;

the self-healing terminals corresponding to the first buses in the switchgears of each group are connected with each other in sequence, and the self-healing terminals corresponding to the second buses in the switchgears of each group are connected with each other in sequence.

A second aspect of the embodiments of the present invention provides a power distribution network fault isolation and self-healing method, which is applied to the power distribution network fault isolation and self-healing system provided in the first aspect of the embodiments of the present invention, and the power distribution network fault isolation and self-healing method includes:

the method comprises the steps that a self-healing terminal in a switching station acquires electrical parameters of the switching station, state information of a protection device of the switching station and a jointly-switched small power supply signal sent by the self-healing terminal of an upstream switching station;

the self-healing terminal in the switching station controls the tripping of an outlet according to the electrical parameters of the switching station and the state information of the protection device of the switching station;

the self-healing terminal in the switching station controls the switching of the small power supply according to the jointly-switched small power supply signal sent by the self-healing terminal of the upstream switching station.

A third aspect of the embodiments of the present invention provides a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the steps of the power distribution network fault isolation self-healing method according to the second aspect of the embodiments of the present invention are implemented.

The embodiment of the invention provides a fault isolation and self-healing system for a power distribution network, which comprises: the transformer substation comprises four groups of transformer substations, a plurality of groups of switch stations and at least one first-class power distribution room, wherein a protection device and a self-healing terminal are arranged in each group of switch stations to form a three-level framework of the transformer substations, the switch stations and the power distribution rooms, and the transformer substation is suitable for various grid structures in closed-loop operation and open-loop operation. The protection device is combined with the self-healing terminal, the protection device and the self-healing terminal realize cooperative self-healing through signal quantity interaction, and the self-healing terminal controls outlet tripping and small power supply switching. The embodiment of the invention has the advantages that the protection device is cooperatively matched with the self-healing terminal, the isolation and self-healing capacity is strong, the performance in the aspect of removal and isolation is reliable, the performance in the aspect of self-healing recovery is stable, the internal setting is easy, and the operation and maintenance difficulty is small.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a structural diagram of a power distribution network according to an embodiment of the present invention;

fig. 2 is a structural diagram of a power distribution network fault isolation self-healing system according to an embodiment of the present invention;

fig. 3 is an interaction flow diagram of a power distribution network fault isolation self-healing method according to an embodiment of the present invention;

fig. 4 is a network structure fault diagram of a power distribution network according to an embodiment of the present invention;

fig. 5 is a fault isolation self-healing device for a power distribution network according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a terminal device according to an embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to explain the technical means of the present invention, the following description will be given by way of specific examples.

Referring to fig. 1 and fig. 2, an embodiment of the present invention provides a power distribution network fault isolation self-healing system, including: four groups of substations (S1, S2, S3 and S4), a plurality of groups of switchgears (A switchgear, B switchgear, C switchgear and D switchgear), at least one first-type distribution room;

the multiple groups of switch stations are connected by hands in sequence; the first group of switch stations (A switch stations) are connected with the outgoing line intervals of the first group of substations at the incoming line intervals of the first bus, and the incoming line intervals of the second bus are connected with the outgoing line intervals of the second group of substations at the outgoing line intervals of the second group of substations; the last group of switching stations (D switching stations) are connected with the outgoing line intervals of the fourth group of substations at the incoming line intervals of the first bus, and the outgoing line intervals of the third group of substations at the incoming line intervals of the second bus;

In the embodiment of the invention, four groups of transformer substations, a plurality of groups of switch stations and at least one first-class power distribution room are provided, and an incoming line differential protection device, an outgoing line differential protection device, a bus protection device and a self-healing terminal are arranged in each group of switch stations to form a three-stage framework of the transformer substations, the switch stations and the power distribution rooms, so that the three-stage framework is suitable for various grid structures in closed-loop operation and open-loop operation.

The self-healing terminal of the switching station can collect bus voltage, incoming and outgoing line interval current, switch state nodes and control nodes, and can collect feeder line interval current, switch state nodes and control nodes with small power supplies, and whether other feeder line intervals are collected can be selected according to actual requirements. The self-healing terminal of the distribution room collects the bus voltage quantity, and collects all interval current quantities, the switch state nodes and the control nodes. The self-healing terminal internally comprises an interval differential protection function, an overcurrent direction backup protection function, a bus differential protection function, a failure protection function, a spare power automatic switching function, a small power supply linkage switching function and a self-healing control function.

The line differential protection device comprises a differential protection function and an overcurrent direction backup protection function. The method comprises the following steps that the direction of a current flowing out of a bus is defined as a positive direction, the direction of a current flowing into the bus is defined as a reverse direction, for a transformer substation-switching station network, a positive direction switch adjacent to an open loop point is taken as a first stage, the positive direction switch from the open loop point to a power supply point is sequentially taken as a second stage and a third stage, a feeder line interval is taken as the first stage, the setting time of directional backup protection is gradually increased according to the stages, a two-stage mode can be adopted, namely, a first switch of the power supply point is taken as the second stage, a feeder line interval is taken as the first stage, and; and for the switching station-distribution room network, the outlet switch of the switching station is set according to the second level.

The protection device is combined with the self-healing terminal, the protection device and the self-healing terminal realize cooperative self-healing through signal quantity interaction, and the self-healing terminal controls outlet tripping and small power supply switching. The embodiment of the invention has the advantages that the protection device is cooperatively matched with the self-healing terminal, the isolation and self-healing capacity is strong, the performance in the aspect of removal and isolation is reliable, the performance in the aspect of self-healing recovery is stable, the internal setting is easy, and the operation and maintenance difficulty is small. Meanwhile, the self-healing terminal logic setting only needs to consider the communication transmission at the same level, does not need to consider the communication interaction between an upper stage and a lower stage, and is low in program complexity and easy to develop and maintain.

In some embodiments, within each group of switchyard:

feeder differential protection devices can be configured at the feeder intervals corresponding to the first bus and the feeder intervals corresponding to the second bus.

In some embodiments, within each group of switchyard: the incoming line differential protection device corresponding to the first bus, the outgoing line differential protection device corresponding to the first bus and the bus protection device corresponding to the first bus are all connected with the self-healing terminal corresponding to the first bus through hard nodes.

All through hard nodal connection between each protection device and the self-healing terminal, do not adopt communication connection, need not to change protection device's software and hardware setting, the self-healing device can use with arbitrary protection device cooperation, and the adaptability is stronger.

Communication connections, such as optical fiber communication, are adopted between differential protection devices between the transformer substation and the switch stations, between the differential protection devices and self-healing terminals of adjacent switch stations, and between the self-healing terminals of the distribution rooms.

In some embodiments, the power distribution network fault isolation self-healing system may further include: at least one second type of electricity distribution room;

at least one second type of distribution room forms N distribution room groups; the number of the distribution room groups is the same as that of the first type of distribution rooms; each power distribution room group corresponds to each first type of power distribution room one by one;

for any distribution room group, second-type distribution rooms in the distribution room group are sequentially connected in series and then connected with corresponding first-type distribution rooms;

each second-type power distribution room is provided with a self-healing terminal;

aiming at any distribution room group, the self-healing terminals of the second type of distribution rooms in the distribution room group are sequentially connected in series and then are connected with the self-healing terminals of the corresponding first type of distribution rooms.

Referring to fig. 3, an embodiment of the present invention provides a power distribution network fault isolation and self-healing method, which is applied to the power distribution network fault isolation and self-healing system provided in the embodiment, and the power distribution network fault isolation and self-healing method includes:

s101: the method comprises the steps that a self-healing terminal in a switching station acquires electrical parameters of the switching station, state information of a protection device of the switching station and a jointly-switched small power supply signal sent by the self-healing terminal of an upstream switching station;

s102: the self-healing terminal in the switching station controls the tripping of an outlet according to the electrical parameters of the switching station and the state information of the protection device of the switching station;

s103: the self-healing terminal in the switching station controls the switching of the small power supply according to the jointly-switched small power supply signal sent by the self-healing terminal of the upstream switching station.

In the embodiment of the invention, the self-healing terminal carries out fault isolation and self-healing in cooperation with the protection device according to the electrical parameters of the switching station, the state information of the protection device and the jointly-cut small power supply signal, so that the influence of a small power supply feeder on a fault self-healing system can be met, the self-healing terminal is suitable for a power distribution network containing small power supplies (motors and distributed power supplies), and the quick switching of the self-healing terminal can be ensured.

In the embodiment of the invention, the power distribution network fault isolation self-healing system in the embodiment of the invention forms a backbone network with the switching stations as nodes, and the protection devices (including an incoming line differential protection device, an outgoing line differential protection device, a bus protection device and a feeder line differential protection device) in each switching station are used for fault isolation and self-healing. For a sub-grid network with distribution rooms (including a first type of distribution room and a second type of distribution room) as nodes, only the upstream fault of the first type of distribution room is removed by an incoming line differential protection device of the distribution room, and other faults are processed by self-healing terminals in the distribution rooms. And self-healing terminals of the switch station and the distribution room trip out by controlling an outlet to remove faults.

For a backbone network running in an open loop, the embodiment of the invention preferably adopts a ring network to supply power in a switching mode, the self-healing terminal controls an open loop point to supply power, the backup power automatic switching device is matched with the self-healing terminal to supply power in a self-healing mode through time setting, and the startup delay of the backup power automatic switching device can be 1000 ms. And for the closed-loop operation backbone network, a spare power automatic switching device is selected for power supply recovery. For the open-loop operation of the secondary network, the final-stage distribution room bus-bar switch can be regarded as an open-loop point, and the power supply is recovered by adopting a looped network power supply conversion mode, or the bus-bar switch spare power automatic switching function of each distribution room can be adopted to realize the power supply conversion.

In some embodiments, the electrical parameters of the switchyard include: a bus voltage; s102 may include:

s1021: if the self-healing terminal in the switching station is started and the state information of the protection device of the switching station is actuated, tripping the self-healing terminal outlet in the switching station;

s1022: if the self-healing terminal in the switch station has a self-protection function, the state information of the protection device of the switch station is not actuated, and the bus is in voltage loss, and the self-healing terminal in the switch station trips through a first preset time.

In some embodiments, the first preset time may be 500 ms.

In the embodiment of the invention, a self-healing terminal in a switching station adopts 'passive' outlet trip logic, and when the self-healing terminal and the switching station act, the outlet trip is controlled; the first preset time T is used for waiting for the action of the protection device, and if the protection device does not act but the bus is in voltage loss, the outlet is controlled to trip. The protection device and the self-healing terminal are matched with redundancy, and reliable fault removal is guaranteed.

In some embodiments, the self-healing terminal of the power distribution network adopts an active outlet trip logic, and the self-healing terminal only needs to satisfy the self-protection energy supply logic to protect the energy supply outlet trip.

In some embodiments, S103 may include:

s1031: if the self-healing terminal is a first type of self-healing terminal or a third type of self-healing terminal and receives and obtains the jointly-cutting small power supply signal sent by the self-healing terminal of the upstream switching station, controlling to cut off the feeder line interval with the small power supply of the switching station and sending the jointly-cutting small power supply signal to the self-healing terminal of the downstream switching station;

s1032: if the self-healing terminal is a second type of self-healing terminal, receiving and obtaining a combined cutting small power supply signal sent by the self-healing terminal of the upstream switching station, and the self-healing terminal of the upstream switching station is an adjacent self-healing terminal at an open loop point side, not controlling to cut a feeder line interval with a small power supply of the switching station, and sending the combined cutting small power supply signal to the self-healing terminal of the downstream switching station;

s1033: if the self-healing terminal is a second type of self-healing terminal, receiving and obtaining a combined cutting small power supply signal sent by the self-healing terminal of the upstream switching station, and the self-healing terminal of the upstream switching station is not an adjacent self-healing terminal at the side of an open loop point, controlling and cutting a feeder line interval with a small power supply of the switching station, and no longer sending the combined cutting small power supply signal to the self-healing terminal of the downstream switching station;

the first type of self-healing terminal is a self-healing terminal in a switching station adjacent to the transformer substation, the second type of self-healing terminal is a self-healing terminal in the switching station where the open-loop point is located, and the third type of self-healing terminal is a self-healing terminal in other switching stations except the first type of self-healing terminal and the second type of self-healing terminal.

In some embodiments, S103 may further include:

s1034: determining whether a self-healing terminal of the switching station generates a combined small power supply signal;

s1035: and if the self-healing terminal of the switching station generates the jointly-cut small power supply signal, the jointly-cut small power supply signal is sent to the downstream switching station.

In some embodiments, S1034 may include:

s10341: if the incoming line of the switching station is separated at intervals and has no current, and an action signal of the incoming line protection device is received, the self-healing terminal of the switching station generates a combined small power supply signal;

s10342: if the outgoing line of the switching station is in interval position division and has no current and receives an action signal of the outgoing line protection device, the self-healing terminal of the switching station generates a linkage switching small power supply signal;

s10343: if an action signal of the bus protection device is received, a self-healing terminal of the switching station generates a combined small power supply signal;

s10344: if the incoming line interval division of the switching station or the outgoing line interval division of the upstream switching station is carried out and no current flows in the incoming line interval of the switching station, the self-healing terminal of the switching station generates a combined switching small power signal after a third preset time T3.

In some embodiments, S103 may further include:

s1036: the self-healing terminal in the switching station acquires the amplitude variation and the frequency variation of the bus voltage of the switching station;

s1037: and if the amplitude variation of the bus voltage is greater than a first threshold value or the frequency variation of the bus voltage is greater than a second threshold value, controlling to cut the feeder line interval with the small power supply of the switch station within second preset time.

In some embodiments, the second predetermined time is in a range of 100ms to 1000 ms;

the second preset time T2 is used to wait for an action signal of the protection device.

For the self-healing terminal in the first-class distribution room or the first-class self-healing terminal in the switching station, when the upper-level power supply is in power failure, the self-healing terminal is not started in the protection function, the self-healing terminal detects that the incoming line switch is free of voltage and current, other logics do not act, the incoming line switch is controlled to trip after T1 time delay, and TI is more than or equal to 200ms and less than or equal to 1000 ms.

For the self-healing terminal or the second type of self-healing terminal of the switch station in the final-stage distribution room, the conditions of closing and opening the loop point switch of the self-healing terminal are as follows:

1) "upstream tripping isolation fault + bus three-phase no-voltage of local station + incoming line no-current of local station + voltage of adjacent bus of downstream";

2) the method comprises the steps of 'downstream trip isolation fault + downstream bus voltage-free + local bus voltage'.

The following describes in detail an embodiment of the power distribution network fault isolation self-healing method with reference to a specific embodiment;

fig. 4 shows a network structure fault diagram of an electrical distribution network.

1. When a fault occurs at the side of the transformer station

And when the 10kV bus in the S1 transformer substation loses power, the self-healing terminal of the switch station A and the self-healing terminal of the switch station B detect that the voltage and frequency change of the bus are greater than threshold values, and feeder line branches containing small power supplies are cut off in a delayed mode through T2. And when the self-healing terminal of the switch station A detects that the bus is out of power and other logics are not started, the switch is controlled to trip through T1 delay.

If the 102 switch trips correctly, the self-healing terminal of the B switch station detects that the upstream trip isolation fault, the bus of the B switch station has no voltage, the incoming line has no current, the adjacent bus of the downstream has voltage, and the self-healing terminal of the B switch station closes 105 switches.

If the switch 102 refuses to jump, the self-healing terminal of the switch station A meets the conditions of 'bus differential failure protection starting + bus voltage loss', the switch station A is controlled to trip through T time delay, a signal of long jump 104 is triggered, the switch station A is controlled to carry out automatic switching discharge, the switch station B self-healing terminal is controlled to trip 104, and the switch station B self-healing terminal is closed to a switch 105.

2. When the F2 point fails

2.1, if the 101 and 102 differential protection devices operate, the 101 and 102 switch is tripped to remove the fault.

2.1.1, if the 101 and 102 tripping normally, removing the fault, detecting that the incoming line interval shifts to be in a position division and no current by the self-healing terminal of the switch station A and receiving an action signal of the 102 differential protection device, generating a linkage-cutting small power supply signal and sending the linkage-cutting small power supply signal to a downstream self-healing terminal; the B self-healing terminal receives the connection switching small power supply signal of the A switch station, but the A switch station is not a self-healing terminal of the adjacent side of the ring opening point of the B switch station, the B self-healing terminal controls and cuts off a feeder line branch containing a small power supply, the B switch station self-healing terminal detects an upstream trip isolation fault, a bus of the B switch station is non-voltage, a wire inlet is non-current, a bus adjacent to a downstream is voltage, and the B switch station self-healing terminal is closed by a 105 switch.

2.1.2, if the 101 is tripped, 102 refuses to move, the mother-difference delustering protection device trips 102, 103 and 501, meanwhile, signals of a far trip 101 and 104 are triggered, and the 101 and 104 differential protection devices trip 101 and 104 switches; a, a self-healing terminal of a switching station meets conditions of 'mother error correction protection starting + mother error correction protection device action', exits follow jumps 102, 103 and 501, triggers a far jump 104 signal, generates a joint small power supply signal and sends the signal to a downstream self-healing terminal; the B self-healing terminal receives a connection switching small power supply signal received by the A switch station, but the A switch station is not a self-healing terminal of an adjacent side of a switching point of the B switch station, the B self-healing terminal controls to cut a feeder line branch containing a small power supply, the B switch station self-healing terminal receives a long jump 104 signal, a jump following 104 switch, the B switch station self-healing terminal detects an upstream trip isolation fault, a bus of the B switch station is non-voltage, an incoming line is non-current, a downstream adjacent bus is voltage, and the B switch station self-healing terminal is closed by a 105 switch.

2.2, if the 101 and 102 differential protection devices do not act, the 101 differential protection device starts backup protection, 101 tripping is controlled, a self-healing terminal A and a self-healing terminal B detect bus voltage, the change of the bus frequency is larger than a threshold value, after T2 time delay, the branch circuit containing a small power supply feeder is controlled to be tripped, the self-healing terminal A of a switching station detects bus voltage loss and 102 tripping is controlled to be delayed by T, the self-healing terminal A of the switching station detects that a line inlet switch trips and no current flows, after T3 time delay, a small cross-cut power supply signal is generated and sent to a downstream terminal, the self-healing terminal B receives a small cross-cut power supply signal of the switching station A, but the switching station A is not an adjacent self-healing terminal at the switching ring point side of the switching station B, the self-healing terminal B controls to cut off the branch circuit containing the small power supply feeder, the self-healing terminal B of the switching station detects that an upstream trip isolation fault, and B, closing 105 the switch by the self-healing terminal of the switch station.

3. When a failure occurs at point F3,

3. if the A switch station bus differential protection device acts, the switch of the

trip switch

102, 103, 501 and A01 is controlled, the switch of the

remote trip switch

101 and 104 is triggered, the condition of 'bus differential protection function + bus differential protection device action' of the self-healing terminal of the switch station A is met, the switch of the

remote trip switch

102, 103, 501 and A01 are triggered, the switch of the remote trip switch 104 is triggered, a small cross-cut power supply signal is generated and sent to a downstream self-healing terminal, the standby self-throw discharge of the switch station A is carried out, after the differential protection device of the

switch station

101 and 104 receives the remote trip signal, the

switch

101 and 104 are controlled to trip, the self-healing terminal of the switch station B receives the small cross-cut power supply signal of the remote trip switch 104, the switch station B switch station is immediately cut off and comprises a small power supply feeder branch, the switch station B switch station self-healing terminal detects that the upstream trip isolation fault, the bus voltage.

3.2, if the bus differential protection device of the switch station A does not act, the backup protection action of the differential protection device 101 trips, the A, B self-healing terminal detects that the bus voltage and the frequency change are larger than the threshold value, after the T2 delay, the control tripping comprises a small power feeder branch, the self-healing terminal of the switch station A detects that the bus is in voltage loss, after the T delay, the control 102 trips, the self-healing terminal of the switch station A detects that the incoming line switch trips and does not flow, after the T3 delay, a combined small power signal is generated and sent to a downstream terminal, the conditions of 'bus differential protection starting + bus voltage loss + T delay' of the self-healing terminal of the switch station A meet, the

control

102, 103, 501 and A01 trip, the signal of the remote tripping switch 104 is triggered, the backup self-switching discharge of the switch station A, the self-healing terminal of the switch station B controls 104 and the self-healing terminal of the switch station.

4. When the F4 point fails

The a02 protection device action removes the fault,

4.1, if the A02 switch is correctly tripped, the fault isolation is finished.

4.2, if the A02 switch fails, the bus differential failure protection device of the switch station A jumps 102, 103 and 501, triggers a far-

jump

101 and 104 switch, the self-healing terminal of the switch station A meets the conditions of 'bus differential protection function + bus differential protection device action', the following

jump

102, 103 and 501 triggers a far-jump 104 switch to generate a small cross-cut power signal and send the small cross-cut power signal to a downstream self-healing terminal, the switch station A is subjected to automatic switching discharge, the 101 and 104 differential protection device controls 101 and 104 to trip after receiving the far-jump signal, the self-healing terminal of the switch station B receives the small cross-cut power signal and the small cross-cut power signal, the following jump 104 immediately cuts off a small power feeder branch of the switch station B, the switch station B detects an upstream trip isolation fault, the bus voltage of the station is not provided, the incoming line is not flowed, the adjacent bus of the downstream has pressure, and the switch station B closes a 105 switch.

5. When a failure occurs at point F5,

5.1, if the 103 and 104 differential protection devices act, tripping the 103 and 104 switches;

5.1.1, if 103 and 104 switches trip, removing faults, enabling the self-healing terminal of the switch station A and the self-healing terminal of the switch station B to meet the condition of 'differential protection + protection device action', and jumping the switches 103 and 104, detecting that the outgoing line interval is shifted to be in a position-division state and has no current by the self-healing terminal of the switch station A, receiving an action signal of the differential protection device, generating a small cross-cut power supply signal and sending the small cross-cut power supply signal to a downstream self-healing terminal; the B self-healing terminal receives a combined switching small power signal which receives the A switch station self-healing terminal, but the A switch station self-healing terminal is not an adjacent self-healing terminal on the ring opening point side of the B switch station, the B switch station self-healing terminal controls to cut a feeder line branch containing a small power supply, the B switch station self-healing terminal detects an upstream tripping isolation fault, a bus of the B switch station is non-voltage, an incoming line is non-current, an adjacent bus of a downstream is voltage, and the B switch station self-healing terminal is closed by a 105 switch.

5.1.2, if 103 trips and 104 refuses, the self-healing terminal of the A switching station detects that the outgoing switch trips and has no current and receives a protection device action signal, and a linkage switching small power supply signal is generated and sent to a downstream self-healing terminal; the B self-healing terminal receives a connection-cutting small power supply signal received by the A switching station, but the A switching station self-healing terminal is not an adjacent terminal at the opening ring point side of the B switching station, the B self-healing terminal controls to cut off a feeder line branch containing a small power supply, the condition of 'failure protection function + bus voltage loss' of the B switching station self-healing terminal meets, through time delay T, the control jumps 104, 105 and 502 to trigger the signals of the far jumps 103 and 205, the B switching station backup self-switching discharge, the A switching station self-healing terminal receives the signal of the far jump 103, the following jump 103 is switched, and the C station self-healing terminal receives the signal of the far jump 205 and jumps 205.

5.1.3, if 104 trips, 103 refuses, A switch station bus failure protection device trips 102, 103 and 501 to trigger far-

trip

101 and 104 signals, A switch station self-healing terminal 'failure protection + bus failure device action signal' meets the requirements, A switch station self-healing terminal trips 102, 103 and 501 and 101 and 104 protection device trips 101 and 104, A switch station self-healing terminal receives bus failure device action signal to generate a combined small power signal to be sent to a downstream terminal, A switch station standby self-recovery switching discharge, B switch station self-healing terminal receives combined small power signal received by A switch station self-healing terminal, but A switch station self-healing terminal is not adjacent terminal on B switch station switch ring point side, B switch station terminal controls to cut feeder branch containing small power, B switch station terminal detects upstream trip isolation fault, local station bus, no voltage, no current incoming line incoming, And the adjacent downstream bus has voltage, and the self-healing terminal of the B switching station closes 105 switches. And B, the switch station is subjected to spare power automatic switching discharge.

5.2, if the 103 and 104 differential protection devices do not work, the 103 differential protection device backup protection works, and the 103 switch is tripped. A self-healing terminal of a switch station A meets the condition of 'differential protection logic +103 backup protection action signal', a switch is jumped with the switch 103, the self-healing terminal of the switch station A acquires that an outgoing switch trips and does not have current and receives an action signal of a protection device, a gang-cut small power supply signal is generated and transmitted to a downstream self-healing terminal, the self-healing terminal of a switch station B receives the gang-cut small power supply signal received by the switch station A, but the self-healing terminal of the switch station A is not an adjacent self-healing terminal at the side of a switch ring point of the switch station B, the self-healing terminal of the switch station B controls to cut off a feeder line branch circuit containing a small power supply, the 'differential protection logic + voltage loss' condition of the self-healing terminal of the switch station B meets. The self-healing terminal of the B switching station detects that the upstream trip isolation fault, the bus of the station has no voltage, the incoming line has no current, the adjacent bus of the downstream has voltage, and the self-healing terminal of the B switching station closes 105 switches. And B, the switch station is subjected to spare power automatic switching discharge.

6. When the F6 point fails

6.1, if a bus differential protection device of a B switch station acts, controlling switch-off 104, 105, 502 and B01 switches to trigger a switch of a

remote jump

103 and 205, wherein the self-healing terminal 'bus differential protection function + bus differential protection device action' condition of the B switch station conforms to the conditions of the switch of the

remote jump

104, 105, 502 and B01, triggering the switch of the

remote jump

103 and 205, spare power automatic switching discharge of the B switch station, and after receiving a remote jump signal, controlling the switch of the

remote jump

103 and 205 to trip and self-heal and lock; the self-healing terminal of the station A receives the long jump 103 and the following jump 103, and the self-healing terminal of the station C receives the long jump 205 and the following jump 205.

6.2, if the bus differential protection device of the B switching station does not act, the backup protection action of the 103 differential protection device trips, an outlet switch of a self-healing terminal of the A switching station trips and does not have current and receives a protection action signal, a combined cutting small power signal is generated and sent to a downstream terminal, the self-healing terminal of the B switching station receives the combined cutting small power signal of the self-healing terminal of the A switching station, but the self-healing terminal of the A switching station is not an adjacent self-healing terminal at a switching ring point side of the B switching station, the self-healing terminal of the B switching station controls cutting of a feeder line branch containing a small power supply, the 'bus differential protection + bus no-voltage' condition of the self-healing terminal of the B switching station conforms to, and after time delay T, the self-

healing terminal

104, 105, 502 and B01 are controlled to trip to. The self-healing terminal of the switching station A receives the long jump 103 and the following jump 103, and the self-healing terminal of the switching station C receives the long jump 205 and the following jump 205.

7. When a failure occurs at point F7,

7.1, 105, 205 differential protection device action,

7.1.1, if the 205 switch trips, the fault is removed, the conditions of 'differential protection + protection device action' of a B switch station self-healing terminal and a C switch station self-healing terminal are met, the switches are switched with the

trip

105 and 205, the C switch station self-healing terminal detects that the outgoing line interval is shifted to be in a position division mode and has no current, receives a differential protection device action signal, generates a linkage-switching small power supply signal and sends the linkage-switching small power supply signal to a downstream self-healing terminal; the B switch station self-healing terminal receives the connection cutting small power supply signal of the C switch station, the C switch station is an adjacent self-healing terminal of the ring opening point side of the B switch station, and the B switch station does not cut off a feeder line branch circuit containing a small power supply and is self-healing locked. And B, the switch station is subjected to spare power automatic switching discharge.

7.1.2, if the switch 205 refuses to jump, the mother differential failure protection device of the C switch station jumps out 204, 205 and 503 to trigger a

far jump

105 and 203 signal, the self-healing terminal of the C switch station meets the requirements of 'failure protection + mother differential failure device action signal', the self-healing terminal of the C switch station jumps out 105 and 203, the self-healing terminal of the C switch station receives the mother differential failure device action signal and generates a small cross-cut power signal to be sent to a downstream terminal, the C switch station performs self-switching discharge, the self-healing terminal of the B switch station receives the small cross-cut power signal of the self-healing terminal of the C switch station, the self-healing terminal of the C switch station is an adjacent terminal on the open ring point side of the B switch station, and the B switch station does not cut off a feeder line branch containing a small power supply and performs self-healing locking. And B, the switch station is subjected to spare power automatic switching discharge.

8. When a failure occurs at point F8,

8.1, if the

differential protection devices

203 and 204 act, tripping the

switches

203 and 204;

8.1.1, if both the 203 and 204 switches trip, removing the fault, enabling the 'differential protection + protection device action' conditions of the C switch station self-healing terminal and the D switch station self-healing terminal to be in accordance with, switching with the switches 203 and 204, detecting that the outgoing line interval is shifted to be in a position division and no current by the D switch station self-healing terminal, receiving an action signal of the differential protection device, generating a linkage-switching small power supply signal, and sending the linkage-switching small power supply signal to a downstream self-healing terminal; c, the self-healing terminal of the switching station receives the upstream jointly-cut small power supply signal and cuts off the feeder line interval with the small power supply; c, the self-healing terminal of the switching station detects that the incoming line is shifted into a branch position at intervals and has no current, generates a jointly-switched small power signal when receiving an action signal of the differential protection device, and sends the jointly-switched small power signal at the receiving upstream and the jointly-switched small power signal of the local room to the downstream after taking or logic; the C switching station self-healing terminal is an adjacent self-healing terminal on the ring opening point side of the B switching station, the C switching station self-healing terminal does not cut off a feeder line branch circuit containing a small power supply, the C switching station self-healing terminal detects 'downstream trip isolation fault + downstream bus non-voltage + local station bus voltage', and the B switching station self-healing terminal is closed by a 105 switch.

8.1.2, if the switch station D trips 203 and the switch station D refuses to operate 204, the switch station D self-healing terminal detects that the outgoing switch trips and does not flow and receives a protection device action signal, and a linkage switching small power supply signal is generated and sent to a downstream self-healing terminal; c, the self-healing terminal of the switching station receives a jointly-cut small power supply signal received by the self-healing terminal of the switching station D, and a feeder line interval with a small power supply is cut off; the condition of 'failure protection function + bus voltage loss' of the self-healing terminal of the switch station C is met, after time delay T, the

long jump

203 and 105 signals are triggered by controlling the

jumps

204, 205 and 503, spare power automatic switching discharge of the switch station C is carried out, the self-healing terminal of the switch station D receives the long jump 203 signals, the follow jump 203 switches, and the self-healing terminal of the switch station B closes 105 switches.

8.1.3, if 204 trips, 203 refuses to move, the D-switch station mother error protection device trips 202, 203 and 504 to trigger far tripping 201 and 204 signals, the D-switch station self-healing terminal 'failure protection + mother error protection device action signal' meets the requirements, the D-switch station self-healing terminal trips 202, 203 and 504 and 201 and 204 protection devices trip 201 and 204, the D-switch station self-healing terminal receives the mother error protection device action signal and generates a combined small power supply signal to be sent to a downstream terminal, the D-switch station is automatically switched to discharge, the C-switch station self-healing terminal receives the combined small power supply signal of the D-switch station self-healing terminal, and a feeder line interval with a small power supply is cut; c, the self-healing terminal of the switching station detects that the incoming line is shifted into a branch position at intervals and has no current, generates a jointly-switched small power signal when receiving an action signal of the differential protection device, and sends the jointly-switched small power signal at the receiving upstream and the jointly-switched small power signal of the local room to the downstream after taking or logic; the C switching station self-healing terminal is an adjacent self-healing terminal on the ring opening point side of the B switching station, the C switching station self-healing terminal does not cut off a feeder line branch circuit containing a small power supply, the C switching station self-healing terminal detects 'downstream trip isolation fault + downstream bus non-voltage + local station bus voltage', and the B switching station self-healing terminal is closed by a 105 switch.

8.2, if the

differential protection devices

203 and 204 do not operate, the backup protection of the differential protection device 203 operates, and the switch 203 is tripped. The D switch station self-healing terminal comprises a D switch station self-healing terminal, a D switch station self-healing terminal and a C switch station self-healing terminal, wherein a differential protection logic +203 backup protection action signal meets the condition, a jump 203 switch is followed, the D switch station self-healing terminal acquires that an outlet switch is tripped and has no current and receives a protection device action signal, a gang-cut small power supply signal is generated and transmitted to a downstream self-healing terminal, the C switch station self-healing terminal receives the gang-cut small power supply signal received by the D switch station self-healing terminal, and a feeder line interval; and C, the self-healing terminal of the switching station meets the condition of 'differential protection logic + bus voltage loss', and the control is skipped to 204 after T time delay. C, the self-healing terminal of the switching station detects that the incoming line is subjected to interval displacement and has no current, generates a jointly-switched small power supply signal after T3 time delay, and sends the jointly-switched small power supply signal at the receiving upstream and the locally-connected small power supply signal to the downstream after taking or logic; the C switch station self-healing terminal is adjacent terminal of B switch station ring-opening point side, the C switch station self-healing terminal does not cut off a feeder line branch circuit containing a small power supply, the C switch station self-healing terminal detects 'downstream trip isolation fault + downstream bus non-voltage + local bus voltage', and the B switch station self-healing terminal is closed 105 switches.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

Referring to fig. 5, an embodiment of the present invention further provides a power distribution network fault isolation self-healing device, which includes:

the parameter acquisition module 21 is configured to acquire, by a self-healing terminal in a switching station, an electrical parameter of the switching station, state information of a protection device of the switching station, and a jointly-switched small power signal sent by a self-healing terminal of an upstream switching station;

the first control module 22 is used for controlling the trip of an outlet by the self-healing terminal in the switching station according to the electrical parameters of the switching station and the state information of the protection device of the switching station;

and the second control module 23 is configured to control switching of the small power supply by the self-healing terminal in the switching station according to a jointly-switched small power supply signal sent by the self-healing terminal in the upstream switching station.

In some embodiments, the first control module 22 may include:

the first judging unit 221 is configured to trip an outlet of the self-healing terminal in the switching station if a self-protection function of the self-healing terminal in the switching station is started and the state information of the protection device of the switching station is activated;

the second determining unit 222 is configured to determine that the self-healing terminal in the switch station trips through a first preset time if the self-protection function of the self-healing terminal in the switch station is started, the state information of the protection device of the switch station is inactive, and the bus is under a voltage loss.

In some embodiments, the second control module 23 may include:

the third judging unit 231 is configured to, if the self-healing terminal is a first-class self-healing terminal or a third-class self-healing terminal and receives a jointly-switched small power signal sent by the self-healing terminal of the upstream switching station, control to cut a feeder interval with a small power of the switching station and send the jointly-switched small power signal to the self-healing terminal of the downstream switching station;

a fourth determining unit 232, configured to receive and obtain a jointly-switched small power signal sent by the self-healing terminal of the upstream switching station if the self-healing terminal is a second type of self-healing terminal, and the self-healing terminal of the upstream switching station is an adjacent self-healing terminal on the open-loop side, and then not control to cut a feeder interval with a small power of the switching station, and send the jointly-switched small power signal to the self-healing terminal of the downstream switching station;

a fifth judging unit 233, configured to receive and obtain a jointly-switched small power signal sent by a self-healing terminal of an upstream switching station if the self-healing terminal is a second type of self-healing terminal, and the self-healing terminal of the upstream switching station is not an adjacent self-healing terminal on an open loop side, control to cut a feeder interval with a small power of the switching station, and no longer send the jointly-switched small power signal to the self-healing terminal of a downstream switching station;

In some embodiments, the second control module 23 may further include:

a linkage switching small signal determination unit 234, configured to determine whether a self-healing terminal of the switching station generates a linkage switching small power signal;

and a linkage-switching small-signal sending unit 235, configured to send a linkage-switching small power signal to a self-healing terminal of a downstream switching station if the self-healing terminal of the switching station generates the linkage-switching small power signal.

In some embodiments, the correlated small signal determination module 234 may include:

the first judging subunit 2341 is configured to generate a jointly-switched small power signal by the self-healing terminal of the switching station if the incoming line of the switching station is separated at intervals and has no current and an action signal of the incoming line protection device is received;

the first judging subunit 2342 is configured to, if the outgoing line of the switching station is spaced and has no current, and an action signal of the outgoing line protection device is received, generate a linkage switching small power signal at a self-healing terminal of the switching station;

the first judging subunit 2343 is configured to, if an action signal of the bus protection device is received, generate a linkage switching small power signal by the self-healing terminal of the switching station;

first judgement subunit 2344 for if this switchyard inlet wire interval divides position or the line interval that the upper reaches switch station goes out divides position, and this switchyard inlet wire interval does not have a current, then through the third time of predetermineeing, the self-healing terminal of this switchyard produces the antithetical couplet and cuts little power signal.

In some embodiments, the second control module 23 may further include:

the voltage change amount determining unit 236 is configured to obtain, by the self-healing terminal in the switching station, an amplitude change amount of the bus voltage and a frequency change amount of the bus voltage of the switching station;

and the small power supply cutting unit 237 is configured to control to cut the feeder line interval with the small power supply of the switching station after a second preset time if the amplitude variation of the bus voltage is greater than the first threshold or the frequency variation of the bus voltage is greater than the second threshold.

Fig. 6 is a schematic block diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 6, the terminal device 4 of this embodiment includes: one or more processors 40, a memory 41, and a computer program 42 stored in the memory 41 and executable on the processors 40. The processor 40 implements the steps in the above-described respective content name data processing method embodiments, such as steps S101 to S103 shown in fig. 3, when executing the computer program 42. Alternatively, the processor 40 implements the functions of the respective modules/units in the above-described content name data processing apparatus embodiment, for example, the functions of the modules 21 to 23 shown in fig. 5, when executing the computer program 42.

Illustratively, the computer program 42 may be divided into one or more modules/units, which are stored in the memory 41 and executed by the processor 40 to accomplish the present application. One or more of the modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution of the computer program 42 in the terminal device 4. For example, the computer program 42 may be partitioned into the parameter acquisition module 21, the first control module 22, and the second control module 23.

Terminal device 4 includes, but is not limited to, processor 40, memory 41. Those skilled in the art will appreciate that fig. 6 is only one example of a terminal device and does not constitute a limitation of terminal device 4 and may include more or fewer components than shown, or combine certain components, or different components, e.g., terminal device 4 may also include input devices, output devices, network access devices, buses, etc.

The Processor 40 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The storage 41 may be an internal storage unit of the terminal device, such as a hard disk or a memory of the terminal device. The memory 41 may also be an external storage device of the terminal device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like provided on the terminal device. Further, the memory 41 may also include both an internal storage unit of the terminal device and an external storage device. The memory 41 is used for storing the computer program 42 and other programs and data required by the terminal device. The memory 41 may also be used to temporarily store data that has been output or is to be output.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed terminal device and method may be implemented in other ways. For example, the above-described terminal device embodiments are merely illustrative, and for example, a module or a unit may be divided into only one logical function, and may be implemented in other ways, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method according to the embodiments described above may be implemented by a computer program, which is stored in a computer readable storage medium and used by a processor to implement the steps of the embodiments of the methods described above. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include: any entity or device capable of carrying computer program code, recording medium, U.S. disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution media, and the like. It should be noted that the computer readable medium may include any suitable increase or decrease as required by legislation and patent practice in the jurisdiction, for example, in some jurisdictions, computer readable media may not include electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. The utility model provides a distribution network fault isolation self-healing system which characterized in that includes: the system comprises four groups of transformer substations, a plurality of groups of switch stations and at least one first-type distribution room;

for any one first type of distribution room: in the first-class power distribution room, the incoming line interval of a first bus is connected with the feeder line interval corresponding to the first bus of a first switch station, and the incoming line interval of a second bus is connected with the feeder line interval corresponding to the second bus of the first switch station; wherein the first switchyard is any one of the plurality of groups of switchyards;

2. The power distribution network fault isolation self-healing system of claim 1, wherein within each group of switchyard: the incoming line differential protection device corresponding to the first bus, the outgoing line differential protection device corresponding to the first bus and the bus protection device corresponding to the first bus are all connected with the self-healing terminal corresponding to the first bus through hard nodes.

3. The power distribution network fault isolation self-healing system of claim 1, wherein the power distribution network fault isolation self-healing system further comprises: at least one second type of electricity distribution room;

the at least one second type of distribution room forms N distribution room groups; wherein the number of the distribution room groups is the same as that of the first type of distribution rooms; each power distribution room group corresponds to each first type of power distribution room one by one;

4. The power distribution network fault isolation and self-healing method is applied to the power distribution network fault isolation and self-healing system according to any one of claims 1 to 3, and comprises the following steps:

and the self-healing terminal in the switching station controls the switching of the small power supply according to the jointly-switched small power supply signal sent by the self-healing terminal of the upstream switching station.

5. The method for fault isolation and self-healing of the power distribution network according to claim 4, wherein the electrical parameters of the switching station include: a bus voltage; self-healing terminal in this switchyard according to this switchyard's electrical parameter reaches this switchyard's protection device's state information controls the export trip, includes:

if the self-healing terminal in the switching station is started and the state information of the protection device of the switching station is actuated, tripping the self-healing terminal outlet in the switching station;

if the self-protection function of the self-healing terminal in the switch station is started, the state information of the protection device of the switch station is not actuated, and the bus is under voltage loss, and the self-healing terminal in the switch station trips through a first preset time.

6. The power distribution network fault isolation self-healing method according to claim 4, wherein the controlling switching of the small power source by the self-healing terminal in the switching station according to the jointly-switched small power source signal sent by the self-healing terminal in the upstream switching station comprises:

if the self-healing terminal is a first type of self-healing terminal or a third type of self-healing terminal and receives and obtains the jointly-cutting small power supply signal sent by the self-healing terminal of the upstream switching station, controlling to cut off the feeder line interval with the small power supply of the switching station and sending the jointly-cutting small power supply signal to the self-healing terminal of the downstream switching station;

if the self-healing terminal is a second type of self-healing terminal, receiving and obtaining a combined cutting small power supply signal sent by the self-healing terminal of the upstream switching station, and the self-healing terminal of the upstream switching station is an adjacent self-healing terminal at an open loop point side, not controlling to cut a feeder line interval with a small power supply of the switching station, and sending the combined cutting small power supply signal to the self-healing terminal of the downstream switching station;

if the self-healing terminal is a second type of self-healing terminal, receiving and obtaining a combined cutting small power supply signal sent by the self-healing terminal of the upstream switching station, and the self-healing terminal of the upstream switching station is not an adjacent self-healing terminal at the side of an open loop point, controlling and cutting a feeder line interval with a small power supply of the switching station, and not sending the combined cutting small power supply signal to the self-healing terminal of the downstream switching station;

the first type of self-healing terminal is a self-healing terminal in a switching station adjacent to a transformer substation, the second type of self-healing terminal is a self-healing terminal in the switching station where an open loop point is located, and the third type of self-healing terminal is a self-healing terminal except for the first type of self-healing terminal and other switching stations except the second type of self-healing terminal.

7. The method according to claim 6, wherein the self-healing terminal in the switching station controls switching of the small power supply according to the jointly-switched small power supply signal sent by the self-healing terminal of the upstream switching station, and further comprising:

determining whether a self-healing terminal of the switching station generates a combined small power supply signal;

and if the self-healing terminal of the switching station generates the combined small power supply signal, the combined small power supply signal is sent to the self-healing terminal of the downstream switching station.

8. The method for fault isolation and self-healing of the power distribution network according to claim 7, wherein the determining whether the self-healing terminal of the switching station generates the combined small power signal comprises:

if the incoming line of the switching station is separated at intervals and has no current, and an action signal of the incoming line protection device is received, the self-healing terminal of the switching station generates a combined small power supply signal;

if the outgoing line of the switching station is in interval position division and has no current and receives an action signal of the outgoing line protection device, the self-healing terminal of the switching station generates a linkage switching small power supply signal;

if an action signal of the bus protection device is received, a self-healing terminal of the switching station generates a combined small power supply signal;

if the incoming line interval of the switch station is divided into positions or the outgoing line interval of the upstream switch station is divided into positions, and the incoming line interval of the switch station has no current, the self-healing terminal of the switch station generates a combined switching small power signal after the third preset time.

9. The power distribution network fault isolation self-healing method according to claim 6, wherein the self-healing terminal in the switching station controls switching of the small power supply according to a jointly-switched small power supply signal sent by the self-healing terminal of an upstream switching station, and further comprising:

the self-healing terminal in the switching station acquires the amplitude variation and the frequency variation of the bus voltage of the switching station;

and if the amplitude variation of the bus voltage is greater than a first threshold value or the frequency variation of the bus voltage is greater than a second threshold value, controlling to cut the feeder line interval with the small power supply of the switch station within second preset time.

10. A computer-readable storage medium, which stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the power distribution network fault isolation self-healing method according to any one of claims 4 to 9.