Out-of-step splitting device based on digital-analog decoupling

Abstract

The utility model discloses an out-of-step splitting device based on digital-analog decoupling, and relates to the technical field of safety and stability control of an electric power system. The device comprises a mother board, a master control plug-in unit, a communication plug-in unit, an acquisition plug-in unit, an input plug-in unit, a tripping plug-in unit and a signal plug-in unit, the mother board is provided with a plurality of plug-in unit interconnection terminals, and the plurality of plug-in unit interconnection terminals use a high-speed serial point-to-point communication mode; according to the utility model, the sampling plug-in is compatible with different inputs of a conventional transformer substation and an intelligent transformer substation, collects the voltage and current of a power tie line, and obtains the phase angle change, and when the system is out of synchronization and oscillates, if the oscillation center falls within a predetermined motion range, the device determines the phase angle according to the phase angle oscillation criterion and the oscillation period times. And selectively cutting off a local side switch of the unit or the tie line. According to the utility model, the phase angle out-of-step oscillation criterion is adopted, the influence of the operation mode of a power grid is avoided, complicated setting calculation is not needed, all splitting points are convenient to match, and the operation and maintenance are simple.

Description

Technical Field

[0001] The utility model relates to the technical field of safe and stable control of electric power systems, in particular to an out-of-step decoupling device based on digital-analog decoupling. Background Art

[0002] The operating units of a power plant are connected to the external grid through a step-up transformer. When the power plant's tie line loses synchronization with the main system and oscillates, the amplitude of the oscillating current approaches the amplitude of the three-phase short-circuit current at the generator end. Furthermore, during the system out-of-sync process, the voltage and frequency in certain areas, especially near the oscillation center, will fluctuate significantly, posing a significant threat to the safety of the units and power loads, and even causing large-scale power outages. Therefore, from the perspective of grid operation and the actual situation of the power plant, it is required to decouple the corresponding operating units of the power plant when the system loses sync and oscillation occurs to ensure the safe operation of the system and the power plant.

[0003] In recent years, with the vigorous promotion of smart substations, the out-of-step decoupling device will encounter the problem of inconsistent input and output interfaces between conventional substations and smart substations in field applications, making it difficult to achieve standardized management. Utility Model Content

[0004] In order to solve the above problems, the purpose of the present invention is to provide a step-out decoupling device based on digital-analog decoupling.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions: an out-of-step decoupling device based on digital-analog decoupling, the out-of-step decoupling device includes a motherboard, a main control plug-in, a communication plug-in, an acquisition plug-in, an input plug-in, a trip plug-in and a signal plug-in;

[0006] The motherboard is provided with a plurality of plug-in interconnection terminals, and the plurality of plug-in interconnection terminals are interconnected using a high-speed serial point-to-point communication method and LVDS signals. The motherboard is also provided with a synchronous clock signal for the plurality of plug-in interconnection terminals, and the plurality of synchronous clock signals enable the plurality of plug-in interconnection terminals of the entire device to operate in a synchronous system;

[0007] The master control plug-in is the main control part of the out-of-step decoupling device. Several plug-in interconnection terminals communicate with the master control plug-in and are responsible for the collection, storage, and distribution of all data as well as the judgment and processing of the out-of-step decoupling strategy.

[0008] The communication plug-in is responsible for communication processing with the backend within the station or the remote backend. The communication interface of the communication plug-in includes an Ethernet port and a 485 communication port. The communication plug-in is interconnected with the main control plug-in through the LVDS signal of the motherboard;

[0009] The acquisition plug-in includes analog sampling and digital sampling to achieve digital-analog decoupling. The analog sampling is suitable for field electrical quantities with traditional AC input type, and the digital sampling is suitable for field electrical quantities with merging unit input type. The acquisition plug-in is interconnected with the main control plug-in through the LVDS signal of the motherboard;

[0010] The input end of the input plug-in is connected to the function pressure plate of the device to collect the input signal of the function pressure plate. The input plug-in is interconnected with the main control plug-in through the LVDS signal of the motherboard;

[0011] The trip plug-in includes a traditional relay outlet and an intelligent GOOSE outlet. The external output of the traditional relay outlet is connected to a circuit breaker or an operation box, and the GOOSE outlet is connected to an intelligent terminal. The trip plug-in is interconnected with the main control plug-in through the LVDS signal of the motherboard;

[0012] The signal plug-in is interconnected with the main control plug-in through the LVDS signal of the motherboard, and the output end of the signal plug-in is connected to the central signal equipment through the signal relay.

[0013] Preferably, the main control plug-in includes a central processing unit, a memory module and an external storage module. The main control plug-in also processes the external B code signal to generate a synchronous clock and provide it to each sub-plug-in.

[0014] Preferably, the acquisition plug-in includes a mutual inductor, an A / D conversion module and an FPGA calculation module. The acquisition plug-in supports digital sampling data transmitted by 61850-9-2 and 60044-8. The external interface of the acquisition plug-in can use an SFP optical port. The digital sampling data is multi-channel parallel decoded using FPGA on the digital sampling plug-in, and the sampling values ​​required by the extraction device are used for subsequent calculations.

[0015] Preferably, the acquisition plug-in adapts to the input interfaces of conventional substations and smart substations on site according to application requirements. The acquisition plug-in converts data from different input interfaces into unified digital signals for the device, enabling the same main control program to adapt to different external input interfaces and complete digital-analog decoupling.

[0016] Preferably, the trip plug-in receives the export command of the main control plug-in through the LVDS signal. According to the engineering situation, it can be configured as a conventional export or a GOOSE export according to the site, so that the same main control program can adapt to the conventional substation and smart substation exports.

[0017] Preferably, the out-of-step decoupling device also includes a 4U plug-in box, which includes a box body and a panel. The panel is equipped with a display panel, a light board and an Ethernet interface. The display panel is a touch screen, which includes display and input functions. The touch screen is connected to the main control plug-in via the modbus protocol and an RS-422 interface. The light board is connected to the main control plug-in to indicate the device operation, abnormality, action and alarm status. The Ethernet interface is connected to the main control plug-in, and the device can be downloaded, debugged and configured.

[0018] Preferably, the out-of-step decoupling device further includes a power plug-in compatible with 110 / 220V AC / DC power input, the output end of the power plug-in being connected to the motherboard, and the power plug-in providing 5V, ±12V and 24V power required by other plug-ins, while also providing the 24V power supply required by the touch screen.

[0019] Preferably, the touch screen uses a capacitive screen, and configuration software is used to complete the interface required for the project.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] In this utility model, the sampling plug-in is compatible with the different inputs of both conventional and intelligent substations, collecting the voltage and current of the power tie line and detecting phase angle changes. When the system loses synchronization and oscillates, if the oscillation center falls within a predetermined operating range, the device selectively disconnects the unit or tie line switch based on the phase angle oscillation criterion and the number of oscillation cycles. This utility model uses the phase angle out-of-step oscillation criterion, which is unaffected by the grid operating mode, does not require complex setting calculations, and facilitates coordination between the various decoupling points, simplifying operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a structural diagram of the present utility model.

[0024] Figure 2 This is a schematic diagram of the digital-analog decoupling of the acquisition plug-in of the utility model.

[0025] Figure 3 This is a structural diagram of the 4U plug-in box of the utility model.

[0026] In the figure: 1. Main control plug-in; 2. Acquisition plug-in; 3. Communication plug-in; 4. Input plug-in; 5. Trip plug-in; 6. Signal plug-in; 7. Motherboard; 8. Power plug-in; 9. Touch screen; 10. Mutual inductor; 11. Anti-aliasing filter; 12. A / D conversion module; 13. SFP module; 14. PCS module; 15. Data decoding module; 16. Data processing module; 17. 4U plug-in box; 18. Guide rail; 19. Light board; 20. Debug network port. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Example: Figure 1-3 As shown, the utility model provides an out-of-step decoupling device based on digital-analog decoupling, which includes a motherboard 7, a main control plug-in 1, an acquisition plug-in 2, a communication plug-in 3, an input plug-in 4, a trip plug-in 5, a signal plug-in 6, a motherboard 7, a power plug-in 8 and a 4U plug-in box 17;

[0029] The motherboard 7 is provided with multiple backplane sockets, which provide LVDS signals for interconnecting various plug-ins. The main control plug-in 1, acquisition plug-in 2, communication plug-in 3, input plug-in 4, trip plug-in 5, signal plug-in 6, and power plug-in 8 are fixed to the motherboard 7 through the backplane sockets. The main control plug-in 1 exchanges data with the acquisition plug-in 2, communication plug-in 3, input plug-in 4, trip plug-in 5, and signal plug-in 6 through the LVDS signal lines on the backplane sockets. The power plug-in 8 provides +5V and ±12V power supply to other plug-ins through the socket. The touch screen 9 is interconnected with the main control plug-in 1 using the ModBus protocol via RS485 signals;

[0030] The main control plug-in 1 uses a quad-core processor with a Cortex 7 core and an industrial-grade FPGA chip with a main frequency of 1.4G, 1GB of DDR memory and 8GB of MMS external memory, which fully meet the control requirements of out-of-step decoupling. The industrial-grade FPGA chip is responsible for the LVDS high-speed communication driver, directly interacting with other plug-ins and forwarding data to the quad-core processor;

[0031] Communication plug-in 3 is responsible for communication processing with the backend within the station or the remote backend. The communication interface of communication plug-in 3 includes multiple modes such as Ethernet port and 485 communication port, and supports multiple communication protocols such as 103, 104, and 61850. Communication plug-in 3 and main control plug-in 1 exchange high-speed data through LVDS;

[0032] The input plug-in 4 collects the function pressure plate input and provides it to the main control plug-in 1 through LVDS, providing the function input quantity for strategy judgment;

[0033] Signal plug-in 6 receives the signal command of the main control plug-in 1, and provides the central signal output externally through the signal relay;

[0034] The acquisition plug-in 2 can collect secondary AC circuit signals such as voltage and current of conventional substations or digital sampling signals provided by the merging unit according to the on-site application requirements;

[0035] The process of digital-analog decoupling of acquisition plug-in 2 is as follows Figure 2 As shown;

[0036] If the secondary AC circuit signals such as voltage and current of a conventional substation are connected on site, they are converted into ±5V AC analog small signals through the mutual inductor 10, and then pass through the front-end anti-aliasing filter 11. The filtered signal enters the A / D conversion module 12 and is converted into a discrete sampling point signal. The sampling point signal enters the data processing module 16 and is converted into the digital signal required by the main control plug-in 1, and interacts with the main control plug-in 1 through LVDS;

[0037] If the digital sampling signal provided by the merging unit is accessed on site, the signal is received by the SFP module 13, and then the PCS module 14 performs preliminary processing to extract the corresponding communication message. The communication message enters the data decoding module 15 to extract the required discrete sampling point signal. The sampling point signal enters the data processing module 16 to be converted into the digital signal required by the main control plug-in 1, and interacts with the main control plug-in 1 through LVDS;

[0038] The trip plug-in 5 receives the trip output command issued by the main control plug-in 1 through the LVDS signal. According to the project situation, it can be connected to an external circuit breaker or operation box through the output relay, or it can be connected to the intelligent terminal through the SFP optical port output GOOSE trip signal;

[0039] The touch screen 9 uses an industrial-grade capacitive touch screen. The touch screen 9 uses configuration software to complete engineering design, which is easy to operate and provides friendly human-computer interaction. The touch screen 9 communicates with the main control plug-in 1 using the ModBus protocol.

[0040] The main body of the out-of-step decoupling device is a 4U plug-in box 17, which includes a box body and a panel. The box body includes a guide rail 18 for fixing the main control plug-in 1, the acquisition plug-in 2, the communication plug-in 3, the input plug-in 4, the trip plug-in 5, the signal plug-in 6, the motherboard 7 and the power plug-in 8. A touch screen 9 is embedded on the panel, and there are also a light board 19 and a debugging network port 20. The light board 19 and the debugging network port 20 are also connected to the main control plug-in 1.

[0041] Working principle: The power plug-in 8 is connected to an external 110V / 220V DC power supply on site to provide the +5V, ±12V, and +24V power supplies required by the device;

[0042] The acquisition plug-in 2 collects the secondary voltage and current signals of the tie line or the digital sampling signals of the merging unit according to the needs of the site. The conventional signals undergo low-pass filtering and A / D conversion. The digital sampling signals pass through the PCS module 14 and the data decoding module 15. Both the conventional signals and the digital sampling signals are converted into discrete sampling point signals and enter the data processing module 16. After calculation, they are converted into the phasor data required by the main control plug-in 1 and transmitted to the central processing unit of the main control plug-in 1 via the LVDS signal;

[0043] At the same time, the function pressure plate signal collected by plug-in 4 is also transmitted to the central processor of the main control plug-in 1 through the LVDS signal. When the system loses step, the central processor can calculate the phase angle based on the phasor data of voltage and current, judge that the system is out of step based on the change of the phase angle, and judge the oscillation center based on the low voltage auxiliary judgment criterion, and issue a trip command based on the judgment result;

[0044] After receiving the trip command through the LVDS signal, the trip plug-in 5 can drive the trip coil through the output relay or control the intelligent terminal through the GOOSE signal, thereby tripping the power tie line or the generator set to realize the system decoupling;

[0045] During the operation of the device, the signal plug-in 6 obtains the alarm signal sent by the main control plug-in 1 in real time and outputs it to the external central signal;

[0046] When the device is running, the communication plug-in 3 communicates with the local / remote background in real time, sends the current state quantity, and actively sends action information when taking action.

[0047] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A step-out decoupling device based on digital-analog decoupling, characterized in that: The out-of-step decoupling device comprises a motherboard (7), a main control plug-in (1), a communication plug-in (3), an acquisition plug-in (2), an input plug-in (4), a trip plug-in (5) and a signal plug-in (6); The motherboard (7) is provided with a plurality of plug-in interconnection terminals, and the plurality of plug-in interconnection terminals use a high-speed serial point-to-point communication method and are interconnected using LVDS signals. The motherboard (7) is also provided with a synchronous clock signal for the plurality of plug-in interconnection terminals, and the plurality of synchronous clock signals enable the plurality of plug-in interconnection terminals of the entire device to operate in a synchronous system. The master control plug-in (1) is the main control part of the out-of-step decoupling device, and a plurality of plug-in interconnection terminals communicate with the master control plug-in (1), and are responsible for the collection, storage, and distribution of all data and the judgment and processing of the out-of-step decoupling strategy; The communication plug-in (3) is responsible for communication processing with the backend within the station or the remote backend. The communication interface of the communication plug-in (3) includes an Ethernet port and a 485 communication port. The communication plug-in (3) is interconnected with the main control plug-in (1) via the LVDS signal of the motherboard (7); The acquisition plug-in (2) includes analog sampling and digital sampling to achieve digital-analog decoupling. The analog sampling is suitable for the case where the on-site electrical quantity is a traditional AC input type, and the digital sampling is suitable for the case where the on-site electrical quantity is a merging unit input type. The acquisition plug-in (2) is interconnected with the main control plug-in (1) via the LVDS signal of the motherboard (7); The input end of the input plug-in (4) is connected to the function pressure plate of the device to collect the input signal of the function pressure plate. The input plug-in (4) is interconnected with the main control plug-in (1) via the LVDS signal of the motherboard (7); The trip plug-in (5) includes a traditional relay outlet and an intelligent GOOSE outlet, the traditional relay outlet external output is connected to a circuit breaker or an operation box, the GOOSE outlet is connected to an intelligent terminal, and the trip plug-in (5) is interconnected with the main control plug-in (1) via the LVDS signal of the motherboard (7); The signal plug-in (6) is interconnected with the main control plug-in (1) via the LVDS signal of the motherboard (7), and the output end of the signal plug-in (6) is connected to the central signal device via a signal relay.

2. The out-of-step decoupling device based on digital-analog decoupling according to claim 1, characterized in that: The main control plug-in (1) includes a central processing unit, a memory module and an external memory module. The main control plug-in (1) also includes processing of external B code signals to generate a synchronous clock and provide it to each sub-plug-in.

3. The out-of-step decoupling device based on digital-analog decoupling according to claim 1, characterized in that: The acquisition plug-in (2) includes a mutual inductor (10), an A / D conversion module (12) and an FPGA calculation module. The acquisition plug-in (2) supports digital sampling data transmitted by 61850-9-2 and 60044-8. The external interface of the acquisition plug-in (2) can use an SFP optical port. The digital sampling data is multi-channel parallel decoded using FPGA on the digital sampling plug-in, and the sampling values ​​required by the extraction device are used for subsequent calculation.

4. The out-of-step decoupling device based on digital-analog decoupling according to claim 1, characterized in that: The acquisition plug-in (2) is adapted to the input interfaces of conventional substations and intelligent substations on site according to application requirements. The acquisition plug-in (2) converts data from different input interfaces into a unified digital signal of the device, thereby enabling the same main control program to adapt to different external input interfaces and completing digital-analog decoupling.

5. The out-of-step decoupling device based on digital-analog decoupling according to claim 1, characterized in that: The trip plug-in (5) receives the output command of the main control plug-in (1) via LVDS signals, and can be configured as a conventional output or a GOOSE output according to the project situation, so that the same main control program can be adapted to the outputs of conventional substations and intelligent substations.

6. The out-of-step decoupling device based on digital-analog decoupling according to claim 1, characterized in that: The out-of-step decoupling device further comprises a 4U plug-in box (17), the 4U plug-in box (17) comprises a box body and a panel, a display panel, a light board (19) and an Ethernet interface are mounted on the panel, the display panel is a touch screen (9), comprising display and input functions, the touch screen (9) is connected to the main control plug-in (1) via the modbus protocol and an RS-422 interface, the light board (19) is connected to the main control plug-in (1) to indicate the operation, abnormality, action and alarm status of the device, and the Ethernet interface is connected to the main control plug-in (1) to download, debug and configure the device.

7. The out-of-step decoupling device based on digital-analog decoupling according to claim 6, characterized in that: The out-of-step decoupling device further includes a power supply plug-in (8), which is compatible with 110 / 220V AC / DC power input. The output end of the power supply plug-in (8) is connected to the motherboard (7). The power supply plug-in (8) provides 5V, ±12V and 24V power supplies required by other plug-ins, and also provides 24V power supply required by the touch screen (9).

8. The out-of-step decoupling device based on digital-analog decoupling according to claim 7, characterized in that: The touch screen (9) uses a capacitive screen, and uses configuration software to complete the interface required for the project.

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