A multi-connection complex distribution network fault self-healing system and method

Abstract

The present invention discloses a multi-connection complex distribution network fault self-healing system and method, the fault self-healing system includes at least two substations, the substation is connected to a number of distribution nodes, the distribution nodes are connected to adjacent distribution nodes, the distribution nodes, a number of power terminals powered by the distribution nodes, and the lines between the distribution nodes and the power terminals form a distribution area, and there is at least one line in the distribution area connected to a line in an adjacent distribution area; the fault self-healing method includes disconnecting the distribution node, locating the distribution fault, restoring power supply to the non-fault branch, isolating the fault, and restoring power supply to the fault branch. The present invention divides the distribution network into three levels: substation, distribution node and energy storage reservoir, and power terminal for mesh connection, and uses the energy storage reservoir to assist the distribution network power supply recovery to improve the distribution network fault self-healing ability and shorten the fault self-healing time.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent distribution network, and in particular to a fault self-healing system and method for a multi-connected complex distribution network. Background Art

[0002] The distribution network is located at the end of the power system and plays an important role in connecting the power system and power users and distributing electric energy. With economic development and social progress, users have put forward higher requirements for the safe operation and reliable power supply of the distribution network. Therefore, the smart distribution network developed in conjunction with the existing technology has become a hot research direction. An important feature of the smart distribution network is that it can actively self-heal after a fault, complete fault isolation and power supply restoration in non-fault areas.

[0003] The "Distributed Fault Self-Healing Control Method for Distribution Network" disclosed in Chinese patent documents has a publication number of CN106953306A and a publication date of 2017-07-14. The steps include: the regional agent distribution terminal regularly queries the delay and error of the communication network, and divides the communication network into three levels according to the delay and error. If the network delay is less than 10ms and the short byte has no error, then the A-level network notification is issued; if the network delay is between 10 and 100ms and the short byte has no error, then the B-level network notification is issued; if the network delay is greater than 100ms or there is an error in the short byte, then the C-level network notification is issued; according to the level of the published network notification, the corresponding FA strategy is enabled, and the A-level adopts the query FA, ​​the B-level adopts the permissive FA, and the C-level adopts the local control mode. The distributed fault self-healing control method for distribution network can restore the power supply interval to the greatest extent and improve the power supply reliability. However, there are more and more energy storage stations and micro-new energy power generation points distributed in cities nowadays. The distribution network fault self-healing control method does not consider how to combine energy storage stations and new energy electricity to improve the distribution network's fault self-healing ability and power supply recovery speed. Summary of the invention

[0004] The present invention aims to overcome the problem in the prior art that the energy storage devices and new energy electric energy distributed in various parts of the power grid are not fully utilized to further improve the self-healing ability of the distribution network faults. A multi-connected complex distribution network fault self-healing system and method are provided, which divides the distribution network into three levels: substation, distribution node and energy storage reservoir, and power terminal for mesh connection. The energy storage reservoir is used to assist the distribution network power supply recovery to improve the distribution network fault self-healing ability and shorten the fault self-healing time.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A multi-connected complex distribution network fault self-healing system, characterized in that it includes at least two substations, the substations are connected to a number of distribution nodes, the distribution nodes are connected to adjacent distribution nodes, the distribution nodes, a number of power terminals powered by the distribution nodes, and the distribution nodes and the lines between the power terminals form a distribution area, and there is at least one line in the distribution area connected to a line in an adjacent distribution area.

[0007] The present invention divides the distribution network into three levels. The level where the substation is located is used for the output of electric energy to supply power to the distribution network; the level where the distribution node is located is used for the distribution of electric energy, and the power terminal as the end of the distribution network is the consumption end of electric energy. Networking is first performed inside each level, and then the transmission connection of electric energy is performed between the levels. At the same time, the entire distribution network is divided into a combination of several distribution areas, and the boundaries of each distribution area overlap. A distribution area contains a distribution node and several power terminals and lines between the distribution node and the power terminals. During normal operation, the distribution node is only responsible for the distribution of electricity in the distribution area where it is located. Therefore, when a fault occurs, it is only necessary to isolate the distribution area where the fault is located so that it will not affect the rest of the distribution network. At this time, it is only necessary to perform fault self-healing processing on the isolated distribution area.

[0008] Preferably, the fault self-healing system also includes a plurality of energy storage reservoirs, any one of which can transmit electric energy with the three nearest energy storage reservoirs to form an energy storage network, the energy storage network can store the surplus electric energy of the distribution nodes and the new energy electric energy connected to the power grid, and the energy storage network can supply power to the distribution network.

[0009] The present invention specifically considers the role of energy storage in the self-healing of distribution network faults. The energy storage is first networked into an energy storage network. Any energy storage can transmit energy to three adjacent energy storages. At the same time, the energy storage network and the network composed of distribution nodes are at the same level. The energy storage network is connected to the distribution node network and directly to the power terminals. It can store the remaining electric energy in the distribution network and the new energy electric energy of each micro site; at the same time, it can also connect the electric energy to the distribution network as a supplement, or directly supply power to some power terminals.

[0010] Preferably, the power terminal B(i,j) is provided with a sub-intelligent device W(i,j), and the distribution node Ai is provided with a main intelligent device Wi. The sub-intelligent device W(i,j) sends information to adjacent sub-intelligent devices and the main intelligent device Wi, and the main intelligent device Wi sends information to adjacent main intelligent devices and the distribution center. The intelligent devices control the connection and isolation of the lines.

[0011] In the present invention, intelligent devices are provided to control the connection and isolation of the distribution network. At the same time, the intelligent devices can detect the working information of the distribution network at the location and determine whether there is a fault current passing through. The intelligent devices can exchange information with each other, and the main intelligent device can collect information from all sub-intelligent devices to determine fault information; sub-intelligent devices in a certain area can also exchange information with each other to determine the fault situation in the area.

[0012] A method for self-healing a fault in a multi-connected complex distribution network, characterized by comprising:

[0013] S1. Disconnect the distribution node. After a fault occurs, the distribution node Ai in the distribution area Zi where the fault occurs is disconnected;

[0014] S2. Distribution fault location: detect specific fault information in the power distribution area Zi where power is cut off, compare it with the information of all sub-intelligent devices received by the main intelligent device Wi at the distribution node Ai, and determine the fault location;

[0015] S3, the non-faulty branch resumes power supply. The fault occurs on a branch line of the distribution node Ai, and power supply is restored to the remaining non-faulty lines;

[0016] S4, fault isolation, isolating the part determined to have a fault;

[0017] S5. The power supply of the faulty branch is restored, and the power supply of the remaining parts of the faulty branch that have not failed is restored.

[0018] Preferably, when the fault location located in S2 is at the power distribution node Ai, the fault self-healing method includes:

[0019] S6. Isolate the faulty distribution node Ai and disconnect all connection lines of the distribution node Ai;

[0020] S7. Redistribute the power terminals in the power distribution area Zi. Distribute the power terminals in the power distribution area Zi to adjacent power distribution areas according to the connection relationship, and the adjacent power distribution areas will perform power supply restoration.

[0021] The distribution network fault self-healing method in the present invention mainly takes different steps to restore power supply after classifying the fault location. First, the distribution node fails. Due to the failure of the distribution node Ai, the entire distribution area Zi will be isolated and cannot be re-powered before the distribution node Ai is repaired. Therefore, the adjacent distribution nodes are needed to help the power terminals in the distribution area Zi to restore power. Then, a fault occurs on a branch in the distribution area Zi. At this time, the power supply to the non-fault branch is restored first, and then the power supply to the fault branch is restored after the fault is isolated, which can greatly improve the fault self-healing speed of the distribution network.

[0022] Preferably, S2 comprises the following steps:

[0023] S21, the preliminary fault range is determined, the sub-intelligent device W(i,j) detects the fault current and sends the fault information, and determines that the fault occurs within the connection line range between the power terminal B(i,j) and the adjacent user terminal;

[0024] S22. Accurately locate the fault, collect fault information for the initially determined fault range, and analyze and locate the location where the fault occurs.

[0025] The fault location method of the present invention first defines a larger fault range based on the communication information of the smart device, and then accurately locates the fault location through the fault information collection of the message. This method can narrow the scope of accurate fault location from the entire power distribution area to the range of several power terminals and lines, thereby improving the speed of fault location; at the same time, during the preliminary location, the initially determined fault location and its surrounding area are both determined as the fault range, which can avoid the actual fault point being outside the initially defined fault range.

[0026] Preferably, before disconnecting the power distribution node in S1, the master intelligent device sends information to the nearest energy storage depot, and the energy storage network provides separate power supply to important power terminals in the power distribution area Zi.

[0027] The present invention sends isolation information to the nearest energy storage reservoir before the power distribution area Zi is isolated, and the energy storage reservoir supplies power independently to the important power terminals in the power distribution area Zi. In this way, after the power distribution area Zi is isolated, these independently powered power terminals will not be powered off, thereby ensuring the working stability of the power terminals. This function of restoring power supply to important distribution networks through energy storage networks is of great importance to high-tech enterprises and fine processing enterprises.

[0028] Preferably, the redistribution of power terminals in S7 is performed jointly by the energy storage network and the adjacent power distribution area, and the power terminals are connected to restore power supply according to the principle of optimizing transmission energy consumption.

[0029] Preferably, in the power supply restoration of the S5 fault branch, the power supply to the power terminals of the upstream branch of the fault isolation part is restored by the distribution node Ai; the power supply to the power terminals of the downstream branch of the fault isolation part is restored according to the principle of optimizing transmission energy consumption.

[0030] Preferably, the principle of transmission energy consumption optimization satisfies: the product of the square of the path distance of electric energy transmission to the user terminal and the power load of the user terminal is the transmission energy consumption of the user terminal, and the sum of the transmission energy consumption of all user terminals that need power restoration is minimized.

[0031] The present invention adopts the principle of transmission energy consumption optimization to redesign the power transmission route for power restoration of some power terminals that are out of power in the distribution network, and minimizes the transmission energy consumption load of the newly planned line after power restoration. At the same time, the energy storage network is used to supplement the power supply to the power terminals that need power restoration nearby, reducing the power transmission load from the distribution node to the power terminal, and reducing the impact of the distribution network fault isolation and self-healing on the surrounding distribution network.

[0032] The present invention has the following beneficial effects: the distribution network is divided into three levels, namely, substation, distribution node and energy storage reservoir, and power consumption terminal, and meshed and connected; the energy storage reservoir is used to assist the distribution network in power supply recovery to improve the self-healing ability of the distribution network and shorten the self-healing time; by dividing the areas within the distribution network, one distribution area corresponds to one distribution node and several power consumption terminals, thereby reducing the impact of the fault isolation and self-healing process on the surrounding distribution areas; the intelligent device information exchange is used to preliminarily determine the fault scope, and the detailed detection of the fault information is combined to improve the speed and accuracy of fault location. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a fault self-healing system of the present invention;

[0034] Figure 2 is a schematic diagram of an energy storage network in a fault self-healing system of the present invention;

[0035] Figure 3 is a flow chart of fault self-healing of the present invention;

[0036] Figure 4 It is a schematic diagram of a power distribution area connection of a part of the power distribution network of the present invention;

[0037] Figure 5 It is another distribution area connection schematic diagram of a part of the distribution network of the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0039] like Figure 1 As shown, a multi-connection complex distribution network fault self-healing system includes at least two substations T1 and T2, the substations are connected to a number of distribution nodes Ai, the distribution nodes are connected to adjacent distribution nodes, the distribution nodes Ai, a number of power terminals B (i, j) powered by the distribution nodes, and the distribution nodes and the lines between the power terminals form a distribution area Zi, and there is at least one line in the distribution area Zi that is connected to a line in the adjacent distribution area. Each power terminal has at least two lines connected to other power terminals.

[0040] like Figure 2As shown, the distribution network fault self-healing system also includes several energy storage reservoirs. Any energy storage reservoir can transmit electricity with the three nearest energy storage reservoirs to form an energy storage network. The energy storage network can store the surplus electricity of the distribution nodes and the new energy electricity connected to the power grid. The energy storage network can supply power to the distribution network.

[0041] The power terminal B(i,j) is equipped with a sub-intelligent device W(i,j), and the distribution node Ai is equipped with a main intelligent device Wi. The sub-intelligent device W(i,j) sends information to adjacent sub-intelligent devices and the main intelligent device Wi, and the main intelligent device Wi sends information to adjacent main intelligent devices and the distribution center. The intelligent devices control the connection and isolation of the lines.

[0042] like Figure 3 As shown, a multi-connection complex distribution network fault self-healing method includes:

[0043] S1. Disconnect the distribution node. After a fault occurs, the distribution node Ai in the distribution area Zi where the fault occurs is disconnected;

[0044] S2. Distribution fault location: detect specific fault information in the power distribution area Zi where power is cut off, compare it with the information of all sub-intelligent devices received by the main intelligent device Wi at the distribution node Ai, and determine the fault location;

[0045] S3, the non-faulty branch resumes power supply. The fault occurs on a branch line of the distribution node Ai, and power supply is restored to the remaining non-faulty lines;

[0046] S4, fault isolation, isolating the part determined to have a fault;

[0047] S5. The power supply of the faulty branch is restored, and the power supply of the remaining parts of the faulty branch that have not failed is restored.

[0048] When the fault location located in S2 is at the distribution node Ai, the fault self-healing method includes:

[0049] S6. Isolate the faulty distribution node Ai and disconnect all connection lines of the distribution node Ai;

[0050] S7. Redistribute the power terminals in the power distribution area Zi. Distribute the power terminals in the power distribution area Zi to adjacent power distribution areas according to the connection relationship, and the adjacent power distribution areas will perform power supply restoration.

[0051] The power distribution fault location in S2 includes the following steps:

[0052] S21, the preliminary fault range is determined, the sub-intelligent device W(i,j) detects the fault current and sends the fault information, and determines that the fault occurs within the connection line range between the power terminal B(i,j) and the adjacent user terminal;

[0053] S22. Accurately locate the fault, collect fault information for the initially determined fault range, and analyze and locate the location where the fault occurs.

[0054] Before disconnecting the distribution node in S1, the main intelligent device sends information to the nearest energy storage depot, and the energy storage network provides separate power supply to important power terminals in the distribution area Zi.

[0055] The redistribution of power terminals in S7 is carried out jointly by the energy storage network and the adjacent distribution area, and the power terminals are connected to restore power supply based on the principle of optimizing transmission energy consumption.

[0056] When the S5 fault branch is restored to power, the power supply to the power terminals of the upstream branch of the fault isolation part is restored by the distribution node Ai; the power supply to the power terminals of the downstream branch of the fault isolation part is restored according to the principle of optimizing transmission energy consumption.

[0057] The principle of transmission energy consumption optimization is satisfied: the product of the square of the path distance of power transmission to the user terminal and the power load of the user terminal is the transmission energy consumption of the user terminal, and the sum of the transmission energy consumption of all user terminals that need power restoration is minimized.

[0058] The present invention divides the distribution network into three levels. The level where the substation is located is used for the output of electric energy to supply power to the distribution network; the level where the distribution node is located is used for the distribution of electric energy, and the power terminal as the end of the distribution network is the consumption end of electric energy. Networking is first performed inside each level, and then the transmission connection of electric energy is performed between the levels. At the same time, the entire distribution network is divided into a combination of several distribution areas, and the boundaries of each distribution area overlap. A distribution area contains a distribution node and several power terminals and lines between the distribution node and the power terminal. During normal operation, the distribution node is only responsible for the distribution of electricity in the distribution area where it is located. Therefore, when a fault occurs, it only needs to isolate the distribution area where the fault is located so as not to affect the rest of the distribution network. At this time, it is only necessary to perform fault self-healing processing on the isolated distribution area. Each power terminal has at least two lines connected to other power terminals, which ensures that even if one line fails, the power terminal can restore power supply through another line.

[0059] The present invention specifically considers the role of energy storage in the self-healing of distribution network faults. The energy storage is first networked into an energy storage network. Any energy storage can transmit energy between three adjacent energy storages. At the same time, the network composed of the energy storage network and the distribution node is at the same level. The energy storage network is connected to the distribution node network and directly connected to the power terminal. It can store the remaining electric energy in the distribution network and the new energy electric energy of each micro site; at the same time, it can also connect the electric energy to the distribution network as an electric energy supplement, or directly supply power to some power terminals. In the present invention, the energy storage network is directly connected to each distribution node, so that the energy storage station closest to the distribution node can be selected for remaining electric energy storage and distribution supplement. Since there are too many power terminals in the distribution network, if each power terminal is connected to the energy storage network, it will result in too many lines and increase the probability of failure. Therefore, the energy storage network focuses on connecting important power terminals, including power terminals with strict power supply requirements and user terminals with multiple line connections.

[0060] In the present invention, intelligent devices are provided to control the connection and isolation of the distribution network. At the same time, the intelligent devices can detect the working information of the distribution network at the location and determine whether there is a fault current passing through. The intelligent devices can exchange information with each other, and the main intelligent device can collect information from all sub-intelligent devices to determine fault information; sub-intelligent devices in a certain area can also exchange information with each other to determine the fault situation in the area.

[0061] The distribution network fault self-healing method in the present invention mainly takes different steps to restore power supply after classifying the fault location. First, the distribution node fails. Due to the failure of the distribution node Ai, the entire distribution area Zi will be isolated and cannot be re-powered before the distribution node Ai is repaired. Therefore, the adjacent distribution nodes are needed to help the power terminals in the distribution area Zi to restore power. Then, a fault occurs on a branch in the distribution area Zi. At this time, the power supply to the non-fault branch is restored first, and then the power supply to the fault branch is restored after the fault is isolated, which can greatly improve the fault self-healing speed of the distribution network.

[0062] The fault location method of the present invention first defines a larger fault range based on the communication information of the smart device, and then accurately locates the fault location through the fault information collection of the message. This method can narrow the scope of accurate fault location from the entire power distribution area to the range of several power terminals and lines, thereby improving the speed of fault location; at the same time, during the preliminary location, the initially determined fault location and its surrounding area are both determined as the fault range, which can avoid the actual fault point being outside the initially defined fault range.

[0063] The present invention sends isolation information to the nearest energy storage reservoir before the power distribution area Zi is isolated, and the energy storage reservoir supplies power independently to the important power terminals in the power distribution area Zi. In this way, after the power distribution area Zi is isolated, these independently powered power terminals will not be powered off, thereby ensuring the working stability of the power terminals. This function of restoring power supply to important distribution networks through energy storage networks is of great importance to high-tech enterprises and fine processing enterprises.

[0064] The present invention adopts the principle of transmission energy consumption optimization to redesign the power transmission route for power restoration of some power terminals that are out of power in the distribution network, and minimizes the transmission energy consumption load of the newly planned line after power restoration. At the same time, the energy storage network is used to supplement the power supply to the power terminals that need power restoration nearby, reducing the power transmission load from the distribution node to the power terminal, and reducing the impact of the distribution network fault isolation and self-healing on the surrounding distribution network.

[0065] Embodiment 1, as Figure 4 The figure shows a schematic diagram of a distribution area connection of a partial distribution network of the present invention, wherein Z1 to Z3 represent three distribution areas, A1 to A3 represent three distribution nodes, B(i,j) represents an electricity terminal, and E1 represents an energy storage station. Lines within the same distribution area are represented by solid lines, and inter-area connection lines are represented by dotted lines.

[0066] when Figure 4 When the power terminal B(1,1) in the figure fails, the distribution node A1 is disconnected and the distribution area Z1 is isolated. At this time, the fault point is located. Due to the failure of the power terminal B(1,1), the sub-intelligent device W(1,1) at the power terminal detects the fault information, and a fault current flows through it. The fault information is sent to other sub-intelligent devices and the main intelligent device W1. At this time, the power terminal B(1,1), the power terminal B(1,5), the power terminal B(1,7) and the three lines connected to the power terminal B(1,1) are determined to be the fault range. Then, the image acquisition equipment, temperature sensors, current and voltage sensors, etc. at each power terminal and the distribution node are used to collect detailed information within the preliminary fault range to determine the exact fault location. Since the fault occurred on the A1-B(1,1) branch of the distribution node A1, the A1-B(1,2), A1-B(1,3) and A1-B(1,4) branches are all non-faulty branches. At this time, the power supply of these three non-faulty branches is restored first, and the distribution node A1 continues to supply power to these three branches. Then, after accurately locating B(1,1) as the fault location and isolating it, it is necessary to restore power to the three power terminals B(1,5), B(1,6) and B(1,7).

[0067] exist Figure 4As can be seen, B(1,5) can restore power through the cross-region line A3-B(3,3)-B(3,8)-B(3,9)-B(3,10)-B(1,5) in distribution area Z3, or it can choose to restore power through the line E1-B(3,8)-B(3,9)-B(3,10)-B(1,5); B(1,6) can restore power through the line A2-B(2,4)-B(2, The cross-regional line of E1-B(1,6) can be used to restore power supply, or the line of E1-B(2,4)-B(2,1)-B(1,6) can be used to restore power supply; B(1,7) can be restored through the line of A1-B(1,2)-B(1,8)-B(1,9)-B(1,7), or the line of A2-B(2,3)-B(2,6)-B(1,9)-B(1,7). These restored power supply lines include both solutions where power is restored directly from the distribution node along the line and solutions where power is restored by the energy storage station. When selecting the power supply restoration line, the principle of optimizing transmission energy consumption is considered, and the line with the shortest transmission distance to the power terminal is selected as the first choice for restoring power supply, and the remaining lines are selected as alternatives. In this way, the fault self-healing process of the distribution network after the fault at B(1,1) is completed.

[0068] Embodiment 2, as Figure 5 The figure shows another distribution area connection schematic diagram of a partial distribution network of the present invention, where Z1 to Z5 represent five distribution areas, A1 to A5 represent five distribution nodes, B(i,j) represents an electricity terminal, and E1 and E2 represent energy storage stations. Lines within the same distribution area are represented by solid lines, and inter-area connection lines are represented by dotted lines. The energy storage station is directly connected to the electricity terminal through which three or more lines pass.

[0069] when Figure 5When the distribution node A1 in the figure fails, the distribution node A1 is disconnected and the distribution area Z1 is isolated. At this time, the fault point is located. Due to the failure of the distribution node A1, the main intelligent device W1 will detect the fault information and the fault current will flow through. At the same time, B(1,1), B(1,2), B(1,3) and B(1,4) also have the probability to detect the information of the fault current flowing through. At this time, it is preliminarily judged that B(1,1), B(1,2), B(1,3), B(1,4) and the area formed by the distribution node A1 are the preliminary fault range. Then, the specific fault location is determined based on the image information within the preliminary fault range identified by artificial intelligence and the collected distribution network data, and it is determined that the distribution node A1 has failed. The distribution node A1 is isolated in the distribution area Z1. At this time, the four branches A1-B(1,1), A1-B(1,2), A1-B(1,3) and A1-B(1,4) are all faulty branches. Therefore, it is necessary to redistribute the power terminals. The adjacent distribution areas Z2, Z3, Z4 and Z5 and the energy storage stations E1 and E2 of the distribution area Z1 re-divide the lines for the user terminals in the distribution area Z1 to restore power supply.

[0070] Depend on Figure 5 It can be seen that after A1 is isolated, all power terminals in the distribution area Z1 can be divided into two parts, B(1,1), B(1,5), B(1,6), B(1,7) and B(1,2), B(1,8), B(1,9) are connected to the two lines L1 and B(1,3), B(1,10), B(1,11) and B(1,4), B(1,12), B(1,13), B(1,14) are connected to the two lines L2. The energy storage station E1 in line L1 can directly restore power to B(1,1) and then restore power to the entire line L1 one by one; it can also decompose line L1 and restore power to the power terminals on line L1 through the lines in the distribution areas Z2, Z3 and Z5 that are connected to line L1. Similarly, the energy storage station E2 in line L2 can directly restore power to B(1,3) or the energy storage station E1 can directly restore power to B(1,12), and then restore power to the entire line L2 one by one; line L2 can also be decomposed, and the power supply to the power terminals on line L2 can be restored through the lines in the distribution areas Z3, Z4 and Z5 that are connected to line L2. At this time, the selection of the line to restore power needs to consider the principle of optimizing transmission energy consumption. Taking the power terminal B(1,j) as an example, the terminal power consumption is recorded as Pj, and the line length for restoring power to the power terminal B(1,j) is Lj. The transmission energy consumption of the power terminal is the product of the square of the line length and the terminal power consumption. We select the power restoration line with the minimum sum of the transmission energy consumption of all power terminals as the preferred connection line for power restoration.

[0071] The above embodiments are further elaborations and illustrations of the present invention for ease of understanding, and are not limitations of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-connection complex distribution network fault self-healing system, characterized in that: The invention comprises at least two substations, wherein the substations are connected to a plurality of distribution nodes, the distribution nodes are connected to adjacent distribution nodes, the distribution nodes, a plurality of power terminals powered by the distribution nodes, and the distribution nodes and the lines between the power terminals form a distribution area, and there is at least one line in the distribution area connected to a line in an adjacent distribution area; It also includes several energy storage reservoirs, any one of which can transmit electric energy with the three nearest energy storage reservoirs to form an energy storage network. The energy storage network is connected to the distribution node network and directly connected to the power terminals; the energy storage reservoir is directly connected to the power terminals through which three or more lines pass.

2. A multi-connection complex distribution network fault self-healing system according to claim 1, characterized in that: The energy storage network can store the surplus electric energy of the distribution nodes and the new energy electric energy connected to the power grid, and the energy storage network can supply power to the distribution network.

3. A multi-connection complex distribution network fault self-healing system according to claim 1, characterized in that: The power terminal B(i,j) is provided with a sub-intelligent device W(i,j), and the distribution node Ai is provided with a main intelligent device Wi. The sub-intelligent device W(i,j) sends information to adjacent sub-intelligent devices and the main intelligent device Wi, and the main intelligent device Wi sends information to adjacent main intelligent devices and the distribution center. The intelligent devices control the connection and isolation of the lines.

4. A multi-connection complex distribution network fault self-healing method, applicable to the multi-connection complex distribution network fault self-healing system according to claim 3, characterized in that: include: S1. Disconnect the distribution node. After a fault occurs, the distribution node Ai in the distribution area Zi where the fault occurs is disconnected; S2. Distribution fault location: detect specific fault information in the power distribution area Zi where power is cut off, compare it with the information of all sub-intelligent devices received by the main intelligent device Wi at the distribution node Ai, and determine the fault location; S3, the non-faulty branch resumes power supply. The fault occurs on a branch line of the distribution node Ai, and the distribution node Ai resumes power supply to the remaining non-faulty lines; S4, fault isolation, isolating the part determined to have a fault; S5. The power supply of the faulty branch is restored, and the power supply of the remaining parts of the faulty branch that have not failed is restored.

5. A multi-connection complex distribution network fault self-healing method according to claim 4, characterized in that: When the fault location located in S2 is at the power distribution node Ai, the fault self-healing method includes: S6. Isolate the faulty distribution node Ai and disconnect all connection lines of the distribution node Ai; S7. Redistribute the power terminals in the power distribution area Zi. Distribute the power terminals in the power distribution area Zi to adjacent power distribution areas according to the connection relationship, and the adjacent power distribution areas will perform power supply restoration.

6. A multi-connection complex distribution network fault self-healing method according to claim 4, characterized in that: The S2 comprises the following steps: S21, preliminary fault range determination, the sub-intelligent device W(i,j) detects the fault current and sends fault information, and determines that the fault occurs within the connection line range between the power terminal Bij and the adjacent power terminal; S22. Accurately locate the fault, collect fault information for the initially determined fault range, and analyze and locate the location where the fault occurs.

7. A multi-connection complex distribution network fault self-healing method according to claim 4, characterized in that: Before disconnecting the power distribution node in S1, the master intelligent device sends information to the nearest energy storage depot, and the energy storage network provides separate power supply to important power consumption terminals in the power distribution area Zi.

8. A multi-connection complex distribution network fault self-healing method according to claim 5, characterized in that: The redistribution of power terminals in S7 is performed jointly by the energy storage network and the adjacent power distribution area, and the power terminals are connected to restore power supply according to the principle of optimizing transmission energy consumption.

9. A multi-connection complex distribution network fault self-healing method according to claim 4, characterized in that: When the S5 fault branch is restored to power, the power terminals of the upstream branch of the fault isolation part are restored to power by the distribution node Ai; the power terminals of the downstream branch of the fault isolation part are restored to power according to the principle of optimizing transmission energy consumption.

10. A multi-connection complex distribution network fault self-healing method according to claim 8 or 9, characterized in that: The principle of transmission energy consumption optimization satisfies: the product of the square of the path distance of electric energy transmission to the power terminal and the power load of the power terminal is the transmission energy consumption of the power terminal, and the sum of the transmission energy consumption of all power terminals that need power restoration is minimized.

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