WO2021139071A1

WO2021139071A1 - Smart outdoor switch cabinet, and closed-loop i-shaped power distribution network for same

Info

Publication number: WO2021139071A1
Application number: PCT/CN2020/092607
Authority: WO
Inventors: 涂景添; 李家良; 宋国; 李恒昭; 柯春裕
Original assignee: 赫兹曼电力（广东）有限公司
Priority date: 2020-01-09
Filing date: 2020-05-27
Publication date: 2021-07-15
Also published as: CN111049270A

Abstract

Disclosed are a smart outdoor switch cabinet and a closed-loop I-shaped power distribution network for same. The smart outdoor switch cabinet comprises a cable entry PT and DTU spacer, one or more circuit breaker spacers, and a busbar PT spacer. The PT and DTU spacer comprise a centralized DTU and a cable entry voltage transformer that are mutually electrically connected. Each circuit breaker spacer is provided with a current transformer. The busbar PT spacer is provided with a voltage transformer. The centralized DTU is electrically connected to the current transformer of each circuit breaker spacer, and is electrically connected to the voltage transformer. The present invention uses a centralized DTU, utilizes, by means of an optical fiber differential protection function, a busbar differential protection function, a back-up protection function, an instant overcurrent trip protection function, an automatic backup switching function, and the like provided by the DTU, optical fiber communications to enable information interaction between various switch cabinets, and achieves quick fault isolation of power distribution network circuits and recovery of a power supply to non-fault regions.

Description

Intelligent outdoor switch box and its closed-loop I-shaped power distribution network

Technical field

The invention relates to an intelligent outdoor switch box and a closed-loop I-shaped power distribution network.

Background technique

At present, the domestic distribution network still uses a large number of load switch-fuse combination appliances and load switch products, which are far from meeting the requirements of distributed power construction, strong smart grid, and ubiquitous power Internet of Things. The level of automation is higher than that of Japan, Singapore, etc. The developed countries are poor.

The main wiring methods of domestic medium-voltage cable networks mainly include single-ring network, N-supply and one-backup, and single-shot wiring. When a fault occurs, the power outage range is large, the power outage time is longer, and the power supply reliability is low.

At present, domestic distribution network automation mainly adopts local and centralized solutions. The local type does not rely on the control of the master station. Through the cooperation of voltage, current, and timing, fault isolation and restoration of power supply in non-faulty areas are realized, and the processing time is long. The centralized type requires the cooperation of the master station and each power distribution terminal to realize the isolation of faults and the restoration of power supply in non-faulty areas through remote control or manual methods, which has higher requirements for the master station and communication quality.

Summary of the invention

The purpose of the present invention is to provide an intelligent outdoor switch box and its closed-loop I-shaped distribution network with small power outage range, short power outage time, high power supply reliability, and effectively improve the performance of the distribution network, so as to overcome the problems in the prior art Shortcomings.

An intelligent outdoor switch box designed for this purpose, including incoming PT and DTU intervals, more than one breaker interval and bus PT intervals, PT and DTU intervals including centralized DTUs and incoming voltage transformers that are electrically connected to each other , Each circuit breaker bay is equipped with a current transformer and a circuit breaker switch, the bus PT bay is equipped with a voltage transformer, the centralized DTU and the current transformer of each circuit breaker bay are electrically connected, and the centralized DTU and the voltage transformer are electrically connected. Connect so that the centralized DTU collects the voltage, current, and circuit breaker switch status of all intervals.

Each circuit breaker bay is equipped with a vacuum circuit breaker.

The centralized DTU is equipped with an optical fiber interface for connecting another smart outdoor switch box, and each smart outdoor switch box is equipped with a communication module; the centralized DTU processes the collected voltage, current, and circuit breaker switch status, and uses the optical fiber to Communication module connection; each smart outdoor switch box is connected by optical fiber through the communication module to realize information interaction.

The centralized DTU and the operating mechanism of each breaker interval and bus PT interval are powered by the secondary side of the incoming line PT and the incoming line voltage transformer of the DTU interval.

The centralized DTU collects the voltage, current, and circuit breaker switch status of all intervals, and exchanges information between each smart outdoor switch box, so that the centralized DTU has a fiber optic differential protection module for rapid fault location and isolation , The optical fiber differential protection module includes at least a voltage transformer; the centralized DTU has a bus differential protection module used to quickly locate and isolate the internal fault of the smart outdoor switch box; the centralized DTU is equipped to achieve rapid fault location under abnormal conditions Unlike the isolated backup protection module, the centralized DTU is equipped with a backup self-input module used to quickly restore power after fault isolation; the backup protection module and the backup self-input module include at least a tie breaker switch.

A closed-loop I-shaped power distribution network, comprising the above-mentioned smart outdoor switch box, and two sections of busbars of at least two substations, characterized in that the outlet switch of the first section of the busbar of one of the substations is connected to several smart outdoor switch boxes. Then, it is connected to the outlet switch of the second section of the bus to form a closed loop. The outlet switch of the first section of the bus of another substation is connected to several smart outdoor switch boxes and connected to the outlet switch of the second section of the bus. In order to form another closed loop, one closed loop and the other closed loop form a closed loop I-shaped distribution network through the communication connection between the smart outdoor switch boxes; the switches connected to each other in the closed loop all use circuit breaker switches, and each smart outdoor switch box The internal circuit breaker switches are controlled by centralized DTU.

Circuit breaker switches are divided into loop-in circuit breaker switches, loop-out circuit breaker switches, internal feeder circuit breaker switches, and tie breaker switches according to their functions.

The loop-in circuit breaker switch and the loop-out circuit breaker switch are both closed when the smart outdoor switch box is operating normally.

The beneficial effects of the present invention are as follows:

a. The present invention adopts centralized DTU. Through its optical fiber differential protection function, busbar differential protection function, backup protection function, over-flow protection function, backup automatic switch and other functions, it uses optical fiber communication to realize each switch box The information exchange between them realizes the rapid isolation of faults in the distribution network and the restoration of power supply in non-faulty areas.

b. The present invention does not rely on the master station during the function realization process, and completes fault isolation and power supply restoration on the spot. Due to the accurate location and isolation of the fault, the scope of power outage is greatly reduced. At the same time, due to the closed-loop I-shaped distribution grid, when the first fault occurs, the power outage time in the non-faulty area is zero, which greatly improves the reliability of power supply. The use of advanced optical fiber network for information interconnection enables the restoration of power supply in non-faulty areas within milliseconds even if two failures occur at the same time.

Description of the drawings

Fig. 1 is a schematic diagram of a smart outdoor switch box according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a partial structure of a smart outdoor switch box according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a closed-loop I-shaped distribution network grid structure according to an embodiment of the present invention.

Fig. 4 is a processing of the first failure between smart outdoor switch boxes in a closed-loop I-shaped distribution network grid according to an embodiment of the present invention.

Fig. 5 is a processing of a second fault occurring between smart outdoor switch boxes in a closed-loop I-shaped distribution network grid according to an embodiment of the present invention.

Fig. 6 is the processing of the busbar fault in the smart outdoor switch box in the closed-loop I-shaped distribution network grid according to an embodiment of the present invention.

Fig. 7 shows the processing of a feeder fault in a smart outdoor switch box in a closed-loop I-shaped distribution network frame according to an embodiment of the present invention.

Fig. 8 is a schematic diagram of a circuit breaker switch distribution structure of an energy outdoor switch box in a closed-loop I-shaped distribution network grid frame according to an embodiment of the present invention.

In the figure, 1 is the loop-in circuit breaker switch, 2 is the loop-out circuit breaker switch, 3 is the first internal feeder circuit breaker switch, 4 is the second internal feeder circuit breaker switch, 5 is the third internal feeder circuit breaker switch, 6 It is the fourth internal feeder circuit breaker switch, 7 is the inlet PT and DTU interval, 7.1 is the centralized DTU, 8 is the circuit breaker interval, 8.1 is the current transformer, 9 is the bus PT interval, and 9.1 is the voltage transformer.

Detailed ways

The present invention will be further described below in conjunction with the drawings and embodiments.

Refer to Figure 1 to Figure 2, an intelligent outdoor switch box, including incoming PT and DTU bay 7, more than one breaker bay 8 and bus PT bay 9, PT and DTU bay 7 includes centralized DTU that are electrically connected to each other 7.1 and incoming line voltage transformer, each circuit breaker bay 8 is equipped with a current transformer 8.1 and a circuit breaker switch, and the bus PT bay 9 is equipped with a voltage transformer 9.1, which is characterized by: centralized DTU 7.1 and each circuit breaker The current transformer 8.1 of bay 8 is electrically connected, and the centralized DTU 7.1 is electrically connected to the voltage transformer 9.1, so that the centralized DTU 7.1 collects the voltage, current, and circuit breaker switch status of all bays.

Each circuit breaker bay 8 is equipped with a vacuum circuit breaker 8.2.

The centralized DTU 7.1 is equipped with an optical fiber interface for connecting another smart outdoor switch box, and each smart outdoor switch box is equipped with a communication module; the centralized DTU 7.1 processes the collected voltage, current, and circuit breaker switch status, and passes The optical fiber is connected to the communication module; each smart outdoor switch box is connected by optical fiber through the communication module to realize information interaction.

The centralized DTU 7.1, and the operating mechanism of each breaker bay 8 and busbar PT bay 9 are powered by the incoming line PT and the secondary side of the incoming line voltage transformer of DTU bay 7.

The centralized DTU 7.1 collects the voltage, current, and circuit breaker switch status of all intervals, and exchanges information between each smart outdoor switch box, so that the centralized DTU 7.1 has the optical fiber differential for rapid fault location and isolation Protection module, the optical fiber differential protection module includes at least a voltage transformer; the centralized DTU 7.1 has a bus differential protection module that can be used to quickly locate and isolate the internal fault of the smart outdoor switch box; the centralized DTU 7.1 is equipped to achieve abnormal conditions A backup protection module for rapid fault location and isolation. The centralized DTU 7.1 is equipped with a backup automatic switching module for quick restoration of power supply after fault isolation; the backup protection module and the backup automatic switching module include at least a contact breaker switch.

Each smart outdoor switch box includes six to ten compartments. One of the bays includes all-in-one centralized DTU 7.1 functional units and the incoming line voltage transformers set in the bay; one bay includes the bus voltage transformers set in the bay; the other bays include current transformers set in the corresponding bay and Operating mechanism connected to the same interval. The present invention combines the traditional open-loop distribution network into a new closed-loop I-shaped distribution network, adopts a centralized DTU, is equipped with optical fiber differential protection function, busbar differential protection function, overcurrent flow protection function, and backup automatic switching function. The realization does not depend on the master station to complete the fault isolation of the distribution network and quickly restore the power supply, which can effectively reduce the problem of poor power supply reliability due to long power outages and large power outages in traditional distribution networks.

The faults between each smart outdoor switch box are isolated by the centralized DTU 7.1 through the differential protection function. The busbar fault inside the switch box is also isolated by the centralized DTU 7.1 bus differential protection function. The centralized DTU 7.1 controls the feeder at the same time, and realizes the protection of the internal feeder circuit breaker switch by collecting the current of the feeder and the switch status of the circuit breaker. When two failures occur in the same closed loop at the same time, the connection circuit breaker switch realizes the local power supply control function.

The incoming PT and DTU bay 7 include voltage transformers connected to the loop-in circuit breaker switch and loop-out circuit breaker switch, as well as a centralized DTU 7.1, power supply module and communication module. The busbar PT bay 9 includes a voltage transformer 9.1 arranged on the busbar. The circuit breaker bay 8 includes a current transformer and a circuit breaker arranged on the bay. The centralized DTU 7.1 collects and processes all interval voltages, currents, and circuit breaker switch states, and connects them to the communication module through optical fibers. Each smart outdoor switch box uses optical fibers to connect through the communication module to realize information interaction. The power supply of the system is provided by the incoming PT and the power supply module.

Refer to Figure 3, a closed-loop I-shaped distribution network, including the above-mentioned smart outdoor switch box, and two sections of busbars of at least two substations, one of which is connected to a number of smart outdoor switch boxes by the outlet switch of the first section of the busbar of one substation Then, it is connected to the outlet switch of the second section of the bus to form a closed loop. The outlet switch of the first section of the bus of another substation is connected to several smart outdoor switch boxes and connected to the outlet switch of the second section of the bus. In order to form another closed loop, one closed loop and the other closed loop form a closed loop I-shaped distribution network through the cable connection between the smart outdoor switch boxes; the switches connected to each other in the closed loop all use circuit breaker switches, and each smart outdoor switch box The internal circuit breaker switches are controlled by centralized DTU 7.1.

The closed-loop I-shaped distribution network fault isolation and rapid power restoration method of the present invention is based on the above-mentioned closed-loop I-shaped distribution network grid structure. This structure realizes the interconnection of different power sources through the tie lines of the two closed loops through the tie unit, and increases the path of the line to power supply.

As shown in Figures 4-7, the fault handling method of the present invention is further explained. In Figure 4-7, substation A and substation B are the outlet switches of the two bus sections of the two substations. Each smart outdoor switch box is equipped with loop-in circuit breaker switch 1, loop-out circuit breaker switch 2, and first inner feeder circuit breaker switch 3, second inner feeder circuit breaker switch 4, and third inner feeder circuit breaker switch 5 And the fourth inner feeder circuit breaker switch 6; among them, the fourth inner feeder circuit breaker switch 6 of the fourth smart outdoor switch box in the substation A is used as a tie breaker switch, and is connected to the fourteenth intelligent switch of the substation B through optical fiber The fourth inner feeder circuit breaker switch 6 of the outdoor switch box, and the fourth inner feeder circuit breaker switch 6 of the fourteenth smart outdoor switch box are used as tie breaker switches.

1) The first failure occurs between the switch boxes, as shown in Figure 4:

A. The fault occurs between the second and third smart outdoor switch boxes. The loop-out circuit breaker switch 2 of the second smart outdoor switch box and the loop-in circuit breaker switch 1 of the third smart outdoor switch box detect a differential current.

B. Since the differential current is detected and reaches the setting value, the loop-out circuit breaker switch 2 of the second smart outdoor switch box and the loop-in circuit breaker switch 1 of the third smart outdoor switch box trip at the same time to isolate the fault.

C. Due to the closed-loop I-shaped grid, after the fault is isolated, no power outage will occur in the non-faulty area.

2) The second failure occurs simultaneously between the switch boxes, as shown in Figure 5:

A. During the period when the above 1) failure has not been processed and normal operation has not been restored, another fault occurs between the fifth and sixth smart outdoor switch boxes, the loop-out circuit breaker switch 2 of the fifth smart outdoor switch box and the sixth smart The loop-in circuit breaker switch 1 of the outdoor switch box detects a differential current.

B. Since the differential current is detected and reaches the set value, the loop-out circuit breaker switch 2 of the fifth smart outdoor switch box and the loop-in circuit breaker switch 1 of the sixth smart outdoor switch box trip at the same time to isolate the fault.

C. At this time, the non-faulty areas of the third, fourth, and fifth smart outdoor switch boxes lose power, and the fourth inner feeder circuit breaker switch 6 of the fourth smart outdoor switch box is used as a tie breaker switch and starts the self-prepared The switching strategy is to close the fourth internal feeder circuit breaker switch 6 of the fourth smart outdoor switch box to complete the self-healing control of the restoration of power supply in the non-faulty area.

3) Bus failure of smart outdoor switch box, as shown in Figure 6:

A. The second smart outdoor switch box has an internal failure, and the centralized DTU 7.1 of the second smart outdoor switch box detects the bus differential current.

B. Since the busbar differential current is detected and reaches the set value, the loop-in breaker switch 1, loop-out breaker switch 2, and the first inner feeder breaker switch 3 and the second inner feeder of the second smart outdoor switch box are open. The switch 4, the third inner feeder circuit breaker switch 5, and the fourth inner feeder circuit breaker switch 6 trip at the same time to isolate the fault.

C. Due to the closed-loop I-shaped grid, after the fault is isolated, the non-faulty area will not produce power outage.

4) The feeder fault of the smart outdoor switch box, as shown in Figure 7:

A. The feeder line of the third smart outdoor switch box fails, and the centralized DTU 7.1 of the third smart outdoor switch box detects a fault current in the feeder line of the second inner feeder circuit breaker switch 4.

B. Since it is detected that the second inner feeder circuit breaker switch 4 in the third smart outdoor switch box has a fault current and reaches the set value, the second inner feeder circuit breaker switch 4 of the third smart outdoor switch box trips to isolate the fault .

C. There is no need to re-supply if the feeder line fails.

The above are the preferred solutions of the present invention, showing and describing the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments. The above-mentioned embodiments and the description only illustrate the principles of the present invention. The present invention will have various options without departing from the spirit and scope of the present invention. Changes and improvements, these changes and improvements fall within the scope of the claimed invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

An intelligent outdoor switch box, including incoming PT and DTU compartments (7), more than one circuit breaker compartment (8) and bus PT compartments (9). PT and DTU compartments (7) include a centralized type that is electrically connected to each other DTU (7.1) and incoming voltage transformer, each breaker bay (8) is equipped with a current transformer (8.1) and a circuit breaker switch, and the bus PT bay (9) is equipped with a voltage transformer (9.1), its characteristics It lies in: the centralized DTU (7.1) is electrically connected to the current transformer (8.1) of each breaker bay (8), and the centralized DTU (7.1) and the voltage transformer (9.1) are electrically connected to make the centralized DTU (7.1) ) Collect the voltage, current, and switch status of the circuit breaker in all intervals.
The smart outdoor switch box according to claim 1, characterized in that: each circuit breaker bay (8) is provided with a vacuum circuit breaker (8.2).
The smart outdoor switch box according to claim 1, characterized in that: the centralized DTU (7.1) is provided with an optical fiber interface for connecting another smart outdoor switch box, and a communication module is provided between each smart outdoor switch box; DTU (7.1) processes the collected voltage, current, and circuit breaker switch status, and connects it to the communication module through optical fiber; each smart outdoor switch box uses optical fiber to connect through the communication module to realize information interaction.
The intelligent outdoor switch box according to claim 1, characterized in that: the centralized DTU (7.1), and the operating mechanism of each breaker interval (8) and busbar PT interval (9) are separated by incoming PT and DTU ( 7) The incoming line voltage transformer is powered on the secondary side.
The smart outdoor switch box according to any one of claims 1 to 4, characterized in that: the centralized DTU (7.1) collects the voltage, current, and circuit breaker switch status of all intervals, and each smart outdoor switch box performs Information exchange, so that the centralized DTU (7.1) is equipped with a fiber-optic differential protection module for rapid fault location and isolation. The fiber-optic differential protection module includes at least a voltage transformer; the centralized DTU (7.1) is equipped for the realization of smart outdoor The busbar differential protection module for fast positioning and isolation in the case of internal faults in the switch box; centralized DTU (7.1) has a backup protection module for rapid fault location and isolation under abnormal conditions, and centralized DTU (7.1) is equipped for failure After isolation, a standby automatic switching module that quickly restores power supply; the backup protection module and the standby automatic switching module respectively include at least a tie breaker switch.
A closed-loop I-shaped power distribution network, comprising the smart outdoor switch box of claim 1, and two sections of busbars of at least two substations, characterized in that: one of the first section of the busbar of one of the substations is connected to a plurality of outlet switches. After the smart outdoor switch box, it is connected to the outlet switch of the second section of the bus to form a closed loop. The outlet switch of the first section of the bus of another substation is led out and connected to several smart outdoor switch boxes and connected to the second section of the bus. Outgoing switch to form another closed loop. One closed loop and the other closed loop form a closed loop I-shaped distribution network through the cable connection between the smart outdoor switch box; the switches connected to each other in the closed loop all use circuit breaker switches, and each The circuit breaker switches in the smart outdoor switch box are all controlled by a centralized DTU (7.1).
The closed-loop I-shaped distribution network according to claim 6, wherein the circuit breaker switches are divided into loop-in circuit breaker switches, loop-out circuit breaker switches, internal feeder circuit breaker switches, and tie circuit breaker switches according to different functions.
The closed-loop I-shaped distribution network according to claim 7, wherein the loop-in circuit breaker switch and the loop-out circuit breaker switch are both closed when the smart outdoor switch box is operating normally.