Transformer substation main wiring structure and control method thereof

Abstract

The invention provides a transformer substation main wiring structure and a control method thereof. The main wiring structure comprises a common interbus; a plurality of mutually independent section buses, wherein the leading-out end of each section bus is connected to the common interbus through an interconnecting circuit breaker; the output ends of the transformers are connected with the wire inlet ends of the section buses in a one-to-one correspondence mode through wire inlet circuit breakers, and the input ends of the transformers are connected with the mains supply through high-voltage circuit breakers. And the control module is connected with the control ends of the interconnection circuit breakers and the incoming circuit breakers so as to control the on-off states of the corresponding circuit breakers. The main wiring type is clear in installation, low in cost and convenient to maintain.

Description

Technical Field

[0001] The present invention relates to the application field of electric power equipment, and in particular to a main wiring structure of a transformer substation and a control method thereof. Background Art

[0002] An enterprise's inland river terminal consists of berths, pontoons, loading and unloading production lines, warehouses and other production equipment. An enterprise often has multiple terminals, and each terminal has a completely independent and continuously running loading and unloading production line from the pontoon to the cargo yard. Due to site restrictions, the number of terminal substations is small, the power supply radius is long, and the load fluctuation is large. In order to ensure the normal operation and production efficiency of each terminal production line, stable and reliable power supply is a crucial link.

[0003] The existing technologies mainly include: single bus, single bus segmentation, double bus segmentation. Among them, the single bus is suitable for the situation where there is only one transformer, and the load level is level three, which is not suitable for dock power supply; single bus segmentation and double bus segmentation are the most widely used, and they both require the interconnecting bus to be segmented with circuit breakers. Circuit breakers have the risk of misoperation and require the design of complex electrical interlocking circuits to prevent illegal closing of the loop, and the circuit complexity and construction cost are high. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention proposes a substation main wiring structure and a control method thereof, which mainly solves the problem that the existing substation wiring type is difficult to meet the load requirements of the actual production line, and the circuit is complex and the construction cost is high.

[0005] In order to achieve the above purpose and other purposes, the technical solution adopted by the present invention is as follows.

[0006] The present application provides a main connection structure of a substation, comprising: a common interconnecting bus; a plurality of mutually independent section busbars, wherein the outgoing end of each section busbar is connected to the common interconnecting busbar through an interconnecting circuit breaker; a plurality of transformers, wherein the output ends of the transformers are connected to the incoming ends of the section busbars in a one-to-one correspondence through incoming circuit breakers, and the input ends of the transformers are connected to the mains through high-voltage circuit breakers; and a control module, which is connected to the control ends of the interconnecting circuit breakers and the incoming circuit breakers to control the opening and closing states of the corresponding circuit breakers.

[0007] In one embodiment of the present application, the common interconnecting bus adopts a dense bus duct.

[0008] In one embodiment of the present application, both the tie circuit breaker and the incoming line circuit breaker are drawer-type frame circuit breakers.

[0009] In one embodiment of the present application, the control module includes a programmable logic controller.

[0010] The present application also provides a control method using the main wiring structure of the substation, the control method comprising: in a normal working mode, obtaining status signals of the interconnecting circuit breakers and the incoming circuit breakers of each section bus; performing logical operations according to each of the status signals to generate a locking signal, and cutting off the closing power supply circuit of the corresponding circuit breaker based on the locking signal, so that the interconnecting circuit breaker on the corresponding section bus cannot be closed; taking the faulty section bus or the section bus that needs maintenance as the target section, if the target section exists, cutting off the incoming circuit breaker of the target section to generate a unlocking signal; unlocking the interconnecting circuit breaker of the target section and another normal working section bus according to the unlocking signal, so as to connect the closing power supply circuit of the corresponding interconnecting circuit breaker, and close the corresponding interconnecting circuit breaker, so that the normal working section bus supplies power to the target section.

[0011] In one embodiment, when the locking of the connecting circuit breaker of the target section and another normal working section bus is released according to the locking release signal, it also includes: sending a locking signal to the remaining section buses to disconnect the closing power supply circuit of the corresponding connecting circuit breaker to avoid a closing loop failure.

[0012] In one embodiment, after closing the corresponding connecting circuit breaker so that the busbar of the normal working section supplies power to the target section, it also includes: sending a locking signal to the incoming circuit breaker of the target section to cut off the closing power supply circuit of the corresponding incoming circuit breaker to avoid erroneous closing and electric shock accidents that endanger the safety of maintenance personnel.

[0013] In one embodiment, the method further includes: after the maintenance of the target section is completed or the fault is eliminated, cutting off the connecting circuit breaker of the busbar of the target section and the normal working section, and releasing the lock of the corresponding incoming circuit breaker to allow the incoming circuit breaker of the target section and the normal working section to be closed.

[0014] As described above, a substation main connection structure and a control method thereof proposed in the present application have the following beneficial effects.

[0015] This application uses multiple section buses to supply power to different production lines. The section buses do not interfere with each other. When the equipment of any section bus fails or needs to be repaired and maintained, the corresponding circuit breaker can be disconnected, and the other section buses can operate normally. The section buses are connected through a common bus, and there is no circuit breaker for segmentation. The structure is simple and the operation is convenient. The number of section buses can be expanded according to needs to meet the use requirements of different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the main wiring structure of a substation in one embodiment of the present application.

[0017] Figure 2 It is a flowchart of a control method for a main connection structure of a substation in one embodiment of the present application. DETAILED DESCRIPTION

[0018] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0020] The inventors have found that:

[0021] According to the current power regulations, the enterprise dock is a secondary load, and the substation often uses two 10kV high-voltage power supplies, and the low-voltage side main connection adopts a single busbar segmentation type. When a substation needs to supply power to three or more independent production lines, we find that the single busbar segmentation or double busbar segmentation type has obvious defects: due to the large power of the dock equipment, if the load level is to be maintained at the secondary level, each selected transformer needs to be able to bear the load of all dock equipment, and its capacity will be very high, and the construction cost will also increase accordingly. In the existing technology, one transformer cannot bear all the loads. When any transformer fails or is under maintenance, the relevant dock equipment must be shut down and production must be limited.

[0022] In addition, the power station is equipped with electrical interlocks to prevent illegal closing of circuits and mis-opening and closing of circuit breakers. When there are three or more power supply circuits, the electrical interlock circuit is extremely complex.

[0023] Based on the above problems existing in the prior art, the present application proposes a substation main connection structure and a control method thereof. The technical solution of the present application is elaborated in detail below in conjunction with specific embodiments.

[0024] See also Figure 1 , Figure 1This is a schematic diagram of the main wiring structure of a substation in an embodiment of the present application. The main wiring structure provided in the embodiment of the present application includes: a common interconnecting bus; multiple sections of independent section busbars, the outgoing end of each section busbar is connected to the common interconnecting busbar through a interconnecting circuit breaker; multiple transformers, whose output ends are connected one-to-one with the incoming ends of each section busbar through an incoming circuit breaker, and the input ends of the transformers are connected to the mains through a high-voltage circuit breaker; a control module, which is connected to the control ends of each interconnecting circuit breaker and the incoming circuit breaker to control the opening and closing state of the corresponding circuit breaker. Specifically, each section busbar is connected to the common interconnecting busbar, and each section busbar can be powered by a 10 / 0.4kV transformer. The section busbar is powered by the incoming circuit breaker, and then the equipment in the section (such as the dock loading and unloading production line, etc.) is powered. The section bus is connected to the common interconnecting bus through an interconnecting circuit breaker, which is mainly used for isolation and communication. When the transformer fails or is under maintenance, the section circuit breaker is closed to supply power to the equipment of another section bus through the common interconnecting bus.

[0025] In one embodiment, the incoming circuit breaker and the connecting circuit breaker are drawer-type frame circuit breakers, which can be shaken out and removed after power failure, thereby providing a clearly visible disconnection point.

[0026] In one embodiment, in order to ensure power supply safety and avoid illegal closing or mis-powering accidents, the present application controls the opening and closing state of each circuit breaker through a control module. The control module can be a single-chip microcomputer, a central processing unit chip, etc. Specifically, the control module can be a PLC, which outputs a corresponding locking signal through logical operations, and then controls the closing operation of each circuit breaker.

[0027] In one embodiment, the number of segment buses can be expanded according to actual application requirements. For example, three parallel segment wirings can be set, or four or five segments can be set according to actual production application scenarios. Application expansion is achieved by adding segment buses, and the operation is simple and convenient.

[0028] Taking three sections of busbars as an example, the main connection structure of the embodiment of the present application is composed of a common interconnecting busbar WB0, three sections of busbars WB1 / WB2 / WB3, incoming circuit breakers QF1 / QF2 / QF3, interconnecting circuit breakers QF11 / QF21 / QF31, transformers T1 / T2 / T3, high-voltage circuit breakers Q1 / Q2 / Q3, and protective devices, measuring instruments, etc. The common interconnecting busbar WB0 connects the three sections of busbars, and there is no circuit breaker in the middle for segmentation. The common interconnecting busbar uses a dense bus duct, which has a beautiful appearance, a large current carrying capacity, and is easy to maintain.

[0029] The three sections of busbars WB1 / WB2 / WB3 are separated by interconnecting circuit breakers, and each section independently supplies power to the loading and unloading production line from the incoming circuit breaker. The sections do not interfere with each other, and a transformer failure or power outage in one section does not affect other sections, fully and effectively ensuring the smooth loading and unloading of equipment in each section.

[0030] Each section's incoming line and the closing of the interconnecting circuit breaker are controlled by a PLC. The internally compiled program performs logical operations and outputs a blocking signal to avoid closing loops and mis-powering failures. The application of PLC simplifies the control circuit and ensures safety and reliability.

[0031] Based on the technical solution of the embodiment of the present application, through the design of multiple completely independent section busbars, each production line has a separate transformer for power supply, thereby ensuring the reliability of power supply. By designing a common interconnection busbar, it is allowed to close the interconnection circuit breaker when any section transformer fails or needs maintenance. The load can be quickly transferred to other section buses through the common interconnection busbar, thereby reducing the scope and time of power outages and improving the efficiency of loading and unloading line operations. Each section busbar uses two frame-type circuit breakers to provide isolation function, one is installed between the transformer and the section busbar as an incoming circuit breaker; the other is installed between the section busbar and the common interconnection busbar as an interconnection circuit breaker. In this way, the circuit breaker can be shaken out after power failure, the moving and static contacts are disengaged, and the safety shutter is closed, thereby providing a clearly visible disconnection point to fully ensure safety. The PLC locking signal is innovatively used to control the closing of the circuit breaker, and the status of each circuit breaker is input into an FX series small PLC, and the locking signal is output after logical operation to avoid closing loops and electric shock accidents. One transformer only needs to be able to bear the load of two production lines, not all loads, to raise the load level of production equipment to level 2 or above. The use of PLC as the locking logic judgment greatly reduces the amount of cable laying, simplifies the circuit, and improves reliability. These measures have greatly reduced the cost of substation construction on the basis of fully meeting the power demand of production equipment. This wiring type is easy to expand and upgrade, and the section busbar can be added according to actual needs. At the same time, each section busbar is independent, which is convenient for separate maintenance and overhaul. This main wiring type is clear to install, low cost, and easy to maintain.

[0032] See also Figure 2 , Figure 2 The control method of the embodiment of the present application includes:

[0033] Step S200, in a normal working mode, obtaining status signals of the tie circuit breaker and the incoming circuit breaker of each section bus;

[0034] Step S210, performing a logic operation according to each of the state signals to generate a locking signal, and based on the locking signal, cutting off the closing power supply circuit of the corresponding circuit breaker, so that the tie circuit breaker on the corresponding section bus cannot be closed;

[0035] Step S220, taking the busbar of the faulty section or the busbar of the section that needs to be repaired as the target section, and if the target section exists, cutting off the incoming circuit breaker of the target section to generate a release signal;

[0036] Step S230, according to the unlocking signal, unlocking the interconnecting circuit breaker of the target section and another normal working section bus, so as to connect the closing power supply circuit of the corresponding interconnecting circuit breaker, and close the corresponding interconnecting circuit breaker, so that the normal working section bus supplies power to the target section.

[0037] In one embodiment, when the locking of the connecting circuit breaker of the target section and another normal working section bus is released according to the locking release signal, it also includes: sending a locking signal to the remaining section buses to disconnect the closing power supply circuit of the corresponding connecting circuit breaker to avoid a closing loop failure.

[0038] In one embodiment, after closing the corresponding connecting circuit breaker so that the busbar of the normal working section supplies power to the target section, it also includes: sending a locking signal to the incoming circuit breaker of the target section to cut off the closing power supply circuit of the corresponding incoming circuit breaker to avoid erroneous closing and electric shock accidents that endanger the safety of maintenance personnel.

[0039] In one embodiment, the method further includes: after the maintenance of the target section is completed or the fault is eliminated, cutting off the connecting circuit breaker of the busbar of the target section and the normal working section, and releasing the lock of the corresponding incoming circuit breaker to allow the incoming circuit breaker of the target section and the normal working section to be closed.

[0040] Specifically, the status signals of the six circuit breakers QF1, QF2, QF3, QF11, QF21 and QF31 are respectively transmitted to the input template of the PLC, and the already compiled logic program calculates and issues a blocking signal. The blocking signal cuts off the closing power supply circuit of the circuit breaker, making it impossible to close the circuit, thereby achieving the goal of avoiding misoperation and closing failure.

[0041] Step 1: During normal operation, the three incoming circuit breakers QF1, QF2, and QF3 are in the closed state, the three interconnection circuit breakers QF11, QF21, and QF31 are in the disconnected state, and the three transformers independently supply power to the equipment in each section. The PLC issues a locking command to cut off the closing power supply circuit of the three interconnection circuit breakers, making them unable to close. At this time, the shared interconnection bus WB0 has no power.

[0042] Step 2: When a transformer in any section fails or needs maintenance, first cut off its incoming circuit breaker. After the PLC program operates, it sends a release signal to automatically release the lock of the interconnecting circuit breaker of this section and the interconnecting circuit breaker of the second section, connect the closing power supply circuit of the two circuit breakers, and allow the two interconnecting circuit breakers to close.

[0043] Step 3: Close the second section interconnection circuit breaker, and the common interconnection busbar WB0 is energized. Then close the interconnection circuit breaker of this section, and the second section power supply supplies power to the equipment in this section.

[0044] It should be noted that in this operation, the PLC automatically issued a locking command to the third section interconnecting circuit breaker, cutting off the closing power supply circuit of the third section interconnecting circuit breaker, preventing it from closing, so as to avoid a closing loop failure between the second and third sections.

[0045] At the same time, the PLC automatically issues a locking command to the incoming circuit breaker in this section, cutting off the closing power supply circuit of the incoming circuit breaker in this section so that it cannot be closed, to avoid electric shock accidents caused by misoperation that endanger the safety of maintenance personnel.

[0046] Step 4: When the transformer in this section is overhauled and needs to be put into use, cut off the interconnecting circuit breaker in this section and the interconnecting circuit breaker in the second section. The PLC automatically releases the locking command of the incoming circuit breaker in this section and allows the incoming circuit breaker in this section to be closed.

[0047] Step 5: After the incoming circuit breaker of this section is closed, the transformer of this section supplies power to the equipment of this section, and the three transformers are restored to the normal state of independently supplying power to the equipment of each section. At this time, each interconnection circuit breaker is in the disconnected state, and the shared interconnection busbar WB0 has no power.

[0048] The present invention adopts a programmable controller to analyze and process the disconnection and closing states of the connecting circuit breaker and the incoming circuit breaker, and issue or release the circuit breaker lock to avoid the wrong closing of the connecting circuit breaker and the incoming circuit breaker, thus eliminating the possibility of closing or misoperation accidents.

[0049] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A main wiring structure of a substation, characterized in that: include: Shared interconnection busbar; Multiple sections of mutually independent section busbars, the outgoing line end of each section of the section busbar is connected to the common interconnection busbar through an interconnection circuit breaker; A plurality of transformers, whose output ends are connected to the incoming ends of the busbars of each section through incoming circuit breakers, and whose input ends are connected to the mains through high-voltage circuit breakers; A control module is connected to the control ends of the tie circuit breakers and the incoming circuit breakers to control the opening and closing states of the corresponding circuit breakers.

2. The main connection structure of a substation according to claim 1, characterized in that: The public connecting bus adopts a dense bus duct.

3. The main connection structure of a substation according to claim 1, characterized in that: The connecting circuit breaker and the incoming line circuit breaker both adopt drawer-type frame circuit breakers.

4. The main connection structure of a substation according to claim 1, characterized in that: The control module includes a programmable logic controller.

5. A control method using the main connection structure of a substation according to any one of claims 1 to 4, characterized in that: The control method comprises: In normal working mode, the status signals of the interconnecting circuit breakers and incoming circuit breakers of each section bus are obtained; Performing logic operations according to each of the state signals to generate a locking signal, and cutting off the closing power supply circuit of the corresponding circuit breaker based on the locking signal, so that the connecting circuit breaker on the corresponding section bus cannot be closed; The busbar of the faulty section or the busbar of the section that needs to be repaired is taken as the target section. If the target section exists, the incoming circuit breaker of the target section is cut off to generate a release signal; The locking of the connecting circuit breaker of the target section and another normal working section bus is unlocked according to the unlocking signal to connect the closing power supply circuit of the corresponding connecting circuit breaker, and close the corresponding connecting circuit breaker, so that the normal working section bus supplies power to the target section.

6. The control method according to claim 5, characterized in that: When the locking of the connecting circuit breaker of the target section and another normal working section bus is released according to the locking release signal, it also includes: sending a locking signal to the remaining section buses to disconnect the closing power supply circuit of the corresponding connecting circuit breaker.

7. The control method according to claim 5, characterized in that: After closing the corresponding connecting circuit breaker so that the busbar of the normal working section supplies power to the target section, it also includes: sending a locking signal to the incoming circuit breaker of the target section to cut off the closing power supply circuit of the corresponding incoming circuit breaker.

8. The control method according to claim 5, characterized in that: The method further includes: after the maintenance of the target section is completed or the fault is eliminated, cutting off the connecting circuit breaker of the busbar of the target section and the normal working section, and releasing the lock of the corresponding incoming circuit breaker to allow the incoming circuit breaker of the target section and the normal working section to be closed.

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