An adaptive power distribution grid distributed feeder automation method and system

Abstract

The application belongs to the technical field of power distribution automation, and provides a self-adaptive power distribution network distributed feeder automation method and system. The method comprises the following steps: according to a power distribution network electrical main wiring diagram, corresponding configuration files are configured into each interval unit of a corresponding ring network cabinet; each interval unit automatically identifies the switch type of itself and the switch type of adjacent switches in operation, so that the matching feeder automation function is enabled; when the switch type is a sectionalizing switch, the fault isolation logic is enabled; when the switch type is a tie switch, the power supply recovery logic is enabled. The system can enable each interval unit to automatically enable the corresponding feeder automation function according to the current operation state, and after the system is put into operation in the field, the setting value and configuration no longer need to be modified in operation.

Description

Technical Field

[0001] This invention belongs to the field of power distribution automation technology, and in particular relates to an adaptive method and system for distributed feeder automation in power distribution networks. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In power distribution networks, FA (Feeder Automation) systems are typically configured. When a fault occurs in the distribution network, the FA system can automatically isolate the faulty section and restore power to the non-faulty sections. Currently, FA functions are generally divided into centralized FA, localized FA, and distributed FA. Among these three, distributed FA has the fastest speed in isolating faults and restoring power. Generally, configuring distributed FA in the field with communication capabilities is the best choice to reduce power outage time and improve power supply reliability.

[0004] However, the inventors discovered that each bay unit of the distributed FA (taking the distributed DTU of the ring network cabinet as an example) needs to download the configuration file (such as the ccd file associated with GOOSE) or reconfigure the set values ​​after the operating mode is changed, which will result in a large amount of maintenance work. Summary of the Invention

[0005] To address the technical problems mentioned above, this invention provides an adaptive distributed feeder automation method and system for distribution networks. This system enables each bay unit to automatically enable the corresponding feeder automation function based on its current operating status. After the system is put into operation in the field, it no longer requires modification of settings and configurations during operation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides an adaptive distributed feeder automation method for distribution networks, comprising:

[0008] Configure the corresponding configuration files into each bay unit of the corresponding ring main unit according to the main electrical wiring diagram of the distribution network;

[0009] Each bay unit automatically identifies its own switch type and the switch types of adjacent switches during operation, enabling matching feeder automation functions:

[0010] When the switch type is a segmented switch, enable the fault isolation logic;

[0011] When the switch type is a handshake switch, enable the power supply recovery logic.

[0012] As one implementation method, the condition for determining that the switch is a handshake switch is:

[0013] a) This switch is in the trip position and there is no current.

[0014] b) The switch on the side of the first substation adjacent to this switch is in the closed position and the busbar on that side is energized;

[0015] c) The switch on the side of the second substation adjacent to this switch is in the closed position and the busbar on that side is energized.

[0016] As one implementation method, the condition for determining that the switch is a segmented switch is:

[0017] a) This switch is either in the closed position or has current flowing through it;

[0018] b) The busbar on the first substation side adjacent to this switch is energized, and the busbar on the second substation side adjacent to this switch is energized.

[0019] As one implementation method, the fault isolation logic is as follows:

[0020] When this switch is identified as a sectionalizing switch, if this switch or the switches on both sides detect a fault current and no overcurrent blocking signal is received from the branch switch, the isolation trip protection will be activated.

[0021] If both switches detect fault current during the startup time, the operating conditions are not met.

[0022] If no fault current is detected on one of the two switches during the startup time, the circuit breaker will trip after a set time to isolate the fault area.

[0023] As one implementation method, the power restoration logic is as follows:

[0024] When this switch is identified as a contact switch, if both switches are pressed and closed, it will charge after a certain period of time.

[0025] After charging is complete, if a switch on an adjacent side loses voltage and the load transfer conditions are met, the switch will be closed after a set time after receiving a GOOSE message indicating successful isolation, restoring power supply to the non-faulty area.

[0026] A second aspect of the present invention provides an adaptive distributed feeder automation system for distribution networks, comprising:

[0027] The configuration unit is used to configure the corresponding configuration files into each bay unit of the corresponding ring main unit according to the electrical main wiring diagram of the distribution network.

[0028] The interval unit is used to automatically identify its own switch type and the switch types of adjacent switches during operation, enabling matching feeder automation functions:

[0029] When the switch type is a segmented switch, enable the fault isolation logic;

[0030] When the switch type is a handshake switch, enable the power supply recovery logic.

[0031] In one implementation, the condition for determining that a switch is a handshake switch in the interval unit is:

[0032] a) This switch is in the trip position and there is no current.

[0033] b) The switch on the side of the first substation adjacent to this switch is in the closed position and the busbar on that side is energized;

[0034] c) The switch on the side of the second substation adjacent to this switch is in the closed position and the busbar on that side is energized.

[0035] In one implementation, the condition for determining that a switch is a segmented switch in the interval unit is:

[0036] a) This switch is either in the closed position or has current flowing through it;

[0037] b) The busbar on the first substation side adjacent to this switch is energized, and the busbar on the second substation side adjacent to this switch is energized.

[0038] As one implementation, in the interval unit, the fault isolation logic is as follows:

[0039] When this switch is identified as a sectionalizing switch, if this switch or the switches on both sides detect a fault current and no overcurrent blocking signal is received from the branch switch, the isolation trip protection will be activated.

[0040] If both switches detect fault current during the startup time, the operating conditions are not met.

[0041] If no fault current is detected on one of the two switches during the startup time, the circuit breaker will trip after a set time to isolate the fault area.

[0042] In one implementation, the power supply restoration logic in the interval unit is as follows:

[0043] When this switch is identified as a contact switch, if both switches are pressed and closed, it will charge after a certain period of time.

[0044] After charging is complete, if a switch on an adjacent side loses voltage and the load transfer conditions are met, the switch will be closed after a set time after receiving a GOOSE message indicating successful isolation, restoring power supply to the non-faulty area.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] (1) In this system, each bay unit can automatically identify whether the switch is a regular sectionalizing switch or a tie switch, and enable different FA logic according to different switch types. Therefore, the system only needs to download the configuration file to each bay unit according to the actual electrical main wiring diagram when it is put into operation. No matter how the operating mode changes, the system will operate normally.

[0047] (2) In this system, when a fault occurs, after the fault isolation and power supply to the non-faulty area are restored, if a fault occurs again, the system will still operate normally and continue to isolate the faulty area again.

[0048] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0049] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0050] Figure 1 This is the topology between substations in an embodiment of the present invention;

[0051] Figure 2 This describes the network connection relationship of the ring main unit in this embodiment of the invention;

[0052] Figure 3 This is the power restoration logic of an embodiment of the present invention;

[0053] Figure 4 This is the fault isolation logic in an embodiment of the present invention;

[0054] Figure 5 This is the power distribution network continued operation structure according to an embodiment of the present invention. Detailed Implementation

[0055] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0056] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0057] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0058] Example 1

[0059] This embodiment provides an adaptive distributed feeder automation method for distribution networks, which includes:

[0060] Configure the corresponding configuration files into each bay unit of the corresponding ring main unit according to the main electrical wiring diagram of the distribution network;

[0061] Each bay unit automatically identifies its own switch type and the switch types of adjacent switches during operation, enabling matching feeder automation functions:

[0062] When the switch type is a segmented switch, enable the fault isolation logic;

[0063] When the switch type is a handshake switch, enable the power supply recovery logic.

[0064] This embodiment proposes an adaptive distributed feeder automation (FA) method for distribution networks, which enables each bay unit to automatically enable the corresponding FA function based on its current operating status. After the system is put into operation in the field, no further modifications to settings and configurations are required during operation. Exceptions include situations where new switch bays need to be added in the field, in which case the configurations of several bays connected to the new switch need to be modified.

[0065] by Figure 1 For example, one 10kV outgoing line from substation A supplies power to ring main unit 1 and ring main unit 2, and one 10kV outgoing line from substation B supplies power to ring main unit 3 and ring main unit 4. The C1 switch of ring main unit 3 is a tie switch. Substations A and B serve as backups for each other. When a fault is cleared, the tie switch can be closed, and the backup power supply can continue to supply power to the non-faulty areas.

[0066] In this system, there are two types of switches: sectionalizing switches (connecting switches are a special type of sectionalizing switch) and branch line switches. For example... Figure 1 In the four ring main units, the switches above the busbar are sectional switches, and the switches below the busbar are branch switches. Each ring main unit may have multiple branch switches to supply power to different loads in the area.

[0067] In this system, such as Figure 2As shown, all bay units (each switch corresponds to one bay unit) in the same ring main unit are connected to the switch inside the unit. Switches in adjacent ring main units are cascaded via optical fiber, enabling peer-to-peer communication between all bay units in the four ring main units through GOOSE. According to the topology, the switch closer to substation A is the M side, and the switch closer to substation B is the N side. For example, switch A2 is the N side switch of switch A1, but the M side switch of switch B1. Each section switch needs to subscribe to the GOOSE information of its own M side switch and N side switch (except for the first switch, which only subscribes to the GOOSE information of one side). This information includes: bus voltage, switch position, node fault, successful isolation, switch failure to trip, etc. Each section switch also needs to subscribe to the GOOSE information of all branch switches within its ring main unit, including: branch overcurrent blocking. Branch switches only send GOOSE messages and do not need to subscribe to GOOSE messages.

[0068] Among them, Generic Object Oriented Substation Event (GOOSE) is a mechanism in the IEC 61850 standard used to meet the rapid messaging requirements of substation automation systems. It is primarily used to achieve information transmission between multiple IEDs, including the transmission of trip and close signals (commands), and has a high success rate. Reliable transmission of real-time information such as switch positions, interlocking signals, and trip commands is achieved by replacing traditional hardwiring with GOOSE network transmission.

[0069] In this system, even if the operating status changes, the GOOSE subscription and sending configurations do not need to be reconfigured. For example, if the load on ring main unit 1 increases, substation A cannot supply power to both ring main unit 1 and ring main unit 2 simultaneously. During normal operation, substation B needs to supply power to ring main unit 2, meaning the tie switch needs to be changed from switch C1 to switch B1. This situation can be handled adaptively in this system, eliminating the need for on-site reconfiguration.

[0070] In this system, there is a one-to-one relationship between switches and bay units; one switch corresponds to one bay unit. Switches are primary devices, and bay units are secondary devices. Each bay unit determines the type of switch it manages.

[0071] In this system, the sectionalizing switch determines whether it is a tie switch during normal operation. The determination logic is as follows:

[0072] a) This switch is in the trip position and there is no current.

[0073] b) The switch on the M side is in the closed position and the busbar on the M side is energized;

[0074] c) The N-side switch is in the closed position and the N-side busbar is energized.

[0075] If the conditions are met, this switch will act as a handshake switch, enabling the power supply recovery logic.

[0076] Power restoration logic as follows Figure 3 As shown. Specifically, when this switch is identified as a tie switch, if both switches are energized and closed, it will charge after a certain period of time. After charging is completed, if a switch on an adjacent side loses voltage and the load transfer conditions are met, after receiving the GOOSE message indicating successful isolation, this switch will close after a set time to restore power supply to the non-faulty area.

[0077] If the sectionalizing switch meets the following logic, then this switch is a normal sectionalizing switch, enabling fault isolation logic.

[0078] a) This switch is either in the closed position or has current flowing through it;

[0079] b) Busbar M is under pressure, and busbar N is under pressure.

[0080] Fault isolation logic such as Figure 4 As shown. Specifically, when this switch is identified as a normal sectionalizing switch, if this switch or the switches on both sides detect a fault current and no overcurrent blocking signal is received from the branch switch, the isolation trip protection is activated. If both switches detect a fault current within the activation time, the operating conditions are not met. If one of the switches does not detect a fault current within the activation time, the trip output is generated after a set time, isolating the fault area.

[0081] If a short-circuit fault occurs between switches A2 and B1, switches A2 and B1 will meet the fault isolation logic and trip to isolate the fault area. After the M side of switch C1 loses voltage, upon receiving the isolation success signal from switch B1, it will close after a delay, ensuring the restoration of power supply to the load of ring main unit 2. After successful closing, switch C1 will automatically be identified as a normal sectionalizing switch. If another fault occurs near switch C1, switch C1 will initiate the fault isolation procedure to isolate the fault area again.

[0082] After the fault between switches A2 and B1 is resolved, if the load distribution meets the requirements, the operating unit only needs to manually close switch A2. Switch B1 will be automatically identified as a tie switch, requiring no setting modification or configuration download. This distribution network will then... Figure 5 The program continues to run.

[0083] In this system, each bay unit can automatically identify whether its switch is a regular sectionalizing switch or a tie switch, and enable different FA logic according to different switch types. Therefore, the system only needs to download the configuration file to each bay unit according to the actual electrical main wiring diagram during commissioning, and the system will operate normally regardless of changes in the operating mode.

[0084] In this system, when a fault occurs and power is restored to the non-faulty area after fault isolation, if a fault occurs again, the system will still operate normally and continue to isolate the faulty area again.

[0085] Example 2

[0086] This embodiment provides an adaptive distributed feeder automation system for distribution networks, which includes:

[0087] (1) Configuration unit, which is used to configure the corresponding configuration files into each bay unit of the corresponding ring network cabinet according to the electrical main wiring diagram of the distribution network.

[0088] (2) Interval unit, which is used to automatically identify its own switch type and the switch types of adjacent switches during operation, enabling matching feeder automation functions:

[0089] When the switch type is a segmented switch, enable the fault isolation logic;

[0090] When the switch type is a handshake switch, enable the power supply recovery logic.

[0091] The fault isolation logic is as follows:

[0092] When this switch is identified as a sectionalizing switch, if this switch or the switches on both sides detect a fault current and no overcurrent blocking signal is received from the branch switch, the isolation trip protection will be activated.

[0093] If both switches detect fault current during the startup time, the operating conditions are not met.

[0094] If no fault current is detected on one of the two switches during the startup time, the circuit breaker will trip after a set time to isolate the fault area.

[0095] The power restoration logic is as follows:

[0096] When this switch is identified as a contact switch, if both switches are pressed and closed, it will charge after a certain period of time.

[0097] After charging is complete, if a switch on an adjacent side loses voltage and the load transfer conditions are met, the switch will be closed after a set time after receiving a GOOSE message indicating successful isolation, restoring power supply to the non-faulty area.

[0098] In the specific implementation process, the condition for determining that the switch in the interval unit is a handshake switch is:

[0099] a) This switch is in the trip position and there is no current.

[0100] b) The switch on the side of the first substation adjacent to this switch is in the closed position and the busbar on that side is energized;

[0101] c) The switch on the side of the second substation adjacent to this switch is in the closed position and the busbar on that side is energized.

[0102] In the specific implementation process, the condition for determining that the switch is a segmented switch in the interval unit is:

[0103] a) This switch is either in the closed position or has current flowing through it;

[0104] b) The busbar on the first substation side adjacent to this switch is energized, and the busbar on the second substation side adjacent to this switch is energized.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An adaptive method for distributed feeder automation in distribution networks, characterized in that, include: Configure the corresponding configuration files into each bay unit of the corresponding ring main unit according to the main electrical wiring diagram of the distribution network; Each bay unit obtains its own and adjacent switch positions and bus voltage status in real time through the GOOSE peer-to-peer communication network; Each bay unit automatically identifies its own switch type and the switch types of adjacent switches during operation, enabling matching feeder automation functions: When the switch type is a sectionalizing switch, the fault isolation logic is enabled, specifically as follows: When this switch is identified as a sectionalizing switch, if this switch or the switches on both sides detect a fault current and no overcurrent blocking signal is received from the branch switch, the isolation trip protection will be activated. If both switches detect fault current during the startup time, the operating conditions are not met. If no fault current is detected on one of the two switches during the startup time, the circuit breaker will trip after a set time to isolate the fault area. When the switch type is a handshake switch, the power supply recovery logic is enabled. The power supply recovery logic is as follows: When this switch is identified as a tie switch, if both switches are pressurized and closed, it will charge after a certain period of time; after charging is completed, if the adjacent switch loses pressure and the load transfer conditions are met, after receiving the GOOSE message indicating successful isolation, this switch will close after a set time to restore power supply to the non-faulty area. The condition for determining that a switch is a tie switch is: a) This switch is in the trip position and there is no current. b) The switch on the side of the first substation adjacent to this switch is in the closed position and the busbar on that side is energized; c) The switch on the side of the second substation adjacent to this switch is in the closed position and the busbar on that side is energized; The condition for determining that a switch is a sectionalizing switch is: a) This switch is in the closed position or there is current; b) The busbar on the first substation side adjacent to this switch is energized, and the busbar on the second substation side adjacent to this switch is energized.

2. An adaptive distributed feeder automation system for distribution networks, employing the adaptive distributed feeder automation method for distribution networks as described in claim 1, characterized in that, include: The configuration unit is used to configure the corresponding configuration files into each bay unit of the corresponding ring main unit according to the electrical main wiring diagram of the distribution network. Each bay unit, through the GOOSE peer-to-peer communication network, obtains the switching position and bus voltage status of its own and adjacent switches in real time; it is used to automatically identify its own switch type and the switching types of adjacent switches during operation, enabling matching feeder automation functions: When the switch type is a segmented switch, the fault isolation logic is enabled, specifically as follows: When this switch is identified as a sectionalizing switch, if this switch or the switches on both sides detect a fault current and no overcurrent blocking signal is received from the branch switch, the isolation trip protection will be activated. If both switches detect fault current during the startup time, the operating conditions are not met. If no fault current is detected on one of the two switches during the startup time, the circuit breaker will trip after a set time to isolate the fault area. When the switch type is a handshake switch, enable the power supply recovery logic.

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