A wireless multi-terminal differential protection method and device based on FPGA

Abstract

The present invention discloses a wireless multi-terminal differential protection device based on FPGA. The FPGA processing module is respectively connected to a timing receiving module, an AC plug-in module, a differential protection module and a wireless communication module. The timing receiving module outputs the received timing signal to the FPGA processing module. The AC plug-in module isolates and converts the voltage / current AC electrical quantity into a sampled analog quantity and then outputs it to the FPGA processing module. The differential protection module sends preset configuration parameters to the FPGA processing module and obtains the differential data message sent by the FPGA processing module at the same time. The wireless communication module communicates with the FPGA processing module through an Ethernet interface. The present invention also discloses a wireless multi-terminal differential protection method based on FPGA. The wireless multi-terminal differential protection method and device based on FPGA provided by the present invention can well meet the needs of multi-terminal line differential protection under complex networking, and has the advantages of convenient access, good adaptability and expansibility, short construction period and convenient maintenance.

Description

Technical Field

[0001] The invention relates to a wireless multi-terminal differential protection method and device based on FPGA, belonging to the technical field of power system differential protection. Background Art

[0002] Traditional multi-terminal differential protection is widely used to transmit protection signals through optical fiber communication. It has the advantages of high sensitivity, simplicity, reliability, fast action and good selectivity. However, with the rapid development of distributed new energy and new demands for distribution network line protection, the traditional transmission and distribution line network structure has shown the characteristics of multi-source and multi-terminal. The more complex, denser and more frequently changing transmission and distribution network structure makes it difficult for traditional multi-terminal differential to meet the protection requirements of the current transmission and distribution network, resulting in small protection range, difficult protection setting, difficulty in network construction and transformation, high cost, long cycle, and difficult operation and maintenance.

[0003] Although wireless communication can be used to quickly and easily build a network instead of optical fiber, existing wireless communication equipment has problems such as inconsistent channel routing, unstable transmission delay jitter, etc. If the traditional ping-pong principle is used to synchronize protection data to achieve multi-terminal differential protection, the implementation plan is too complicated, and the requirements for wireless transmission channels are high, occupying too many communication resources, which seriously restricts the application of wireless communication technology in multi-terminal differential protection. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a wireless multi-terminal differential protection method and device based on FPGA, which can well meet the needs of multi-terminal line differential protection under complex networking, and has the advantages of convenient access, good adaptability and scalability, short construction period and convenient maintenance.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A wireless multi-terminal differential protection method, performed by a single differential protection device, comprises the following steps:

[0007] Parse the preset configuration parameters, complete the protocol stack link establishment with other differential protection devices according to the configuration parameter analysis results, and then monitor the link status. If the link is broken, output an alarm and re-establish the link;

[0008] Analyze the timing signal according to the preset configuration parameters, generate synchronous sampling pulses and synchronous sampling moments, and obtain synchronous sampling data using the synchronous sampling pulses;

[0009] The synchronous sampling data and the synchronous sampling time are combined into a sending data message, and transmitted to other differential protection devices via a wireless communication network;

[0010] Receive and buffer received data messages from other differential protection devices;

[0011] According to the synchronous sampling time, the received data message of the synchronous sampling time of other differential protection devices is selected, and the received data message is composed of the synchronous sampling data and the synchronous sampling data;

[0012] If the wireless communication link is normal, the differential data message is forwarded to other differential protection devices;

[0013] Receive differential data messages forwarded by other differential protection devices, obtain the synchronous sampling data of all differential protection devices at any time according to the received differential data messages, calculate and compare according to Kirchhoff's current theorem, and judge whether a fault occurs. If so, output differential control signals to drive the external switch on this side to open and close for control.

[0014] The protocol stack link building is implemented through FPGA.

[0015] The configuration parameters include the analog synchronous sampling frequency, the MAC address and IP address of the Ethernet port.

[0016] The sending data message is organized and sent by the FPGA processing module.

[0017] If the wireless communication link is abnormal, the differential data message processing process is interrupted, the preset configuration parameters are parsed, and the protocol stack link establishment process is completed with other differential protection devices according to the configuration parameter parsing results.

[0018] A wireless multi-terminal differential protection device comprises an FPGA processing module, wherein the FPGA processing module is respectively connected to a timing receiving module, an AC plug-in module, a differential protection module and a wireless communication module, wherein the timing receiving module outputs a received timing signal to the FPGA processing module, the AC plug-in module isolates and converts voltage / current AC electrical quantities into sampled analog quantities and then outputs the same to the FPGA processing module, the differential protection module sends preset configuration parameters to the FPGA processing module, and obtains differential data messages sent by the FPGA processing module, the wireless communication module exchanges communication messages with the FPGA processing module via an Ethernet interface, the differential protection module is connected to a control output module, the differential protection module outputs a differential control signal to the control output module, and the control output module drives an external switch for separation and connection control.

[0019] The FPGA processing module includes a control processing module, which is respectively connected to a time synchronization and analysis module, an analog quantity acquisition module, a message multiplexing and sending module, a message receiving module and a data interaction module, and the message multiplexing and sending module and the message receiving module are connected to an Ethernet module.

[0020] The number of the differential protection devices is N, where N is an integer greater than or equal to 2. A single differential protection device is interconnected with other differential protection devices via the wireless communication module to perform multi-terminal communication message interaction.

[0021] Beneficial effects of the present invention: The present invention provides a wireless multi-terminal differential protection method and device based on FPGA, which implements protocol stack network communication based on FPGA, and guarantees the stability and controllability of processing time and reduces transmission delay to the greatest extent; the synchronous sampling data of all devices is acquired and organized by FPGA to meet the synchronous application requirements of wireless communication in differential protection; the wireless communication technology is used to meet the requirements of multi-terminal line differential protection under complex networking, and has the advantages of convenient access, good adaptability and scalability, short construction period and convenient maintenance. The present invention can well meet the requirements of multi-terminal line differential protection under complex networking, and has the advantages of convenient access, good adaptability and scalability, short construction period and convenient maintenance. When conducting distributed new energy grid connection and distribution network line construction and transformation, the construction difficulty and time can be significantly reduced, and manpower and material costs can be saved. There is no need to maintain the communication link during the operation and maintenance stage, and when a fault occurs, the cause can be quickly found to restore the normal operation of the line. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a system principle schematic diagram of a wireless multi-terminal differential protection device based on FPGA in the present invention;

[0023] Figure 2 It is a functional schematic diagram of the FPGA processing module in the present invention;

[0024] Figure 3 The present invention is a flow chart of a wireless multi-terminal differential protection method based on FPGA. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0026] like Figure 1As shown, the present invention discloses a wireless multi-terminal differential protection device based on FPGA, including a timing receiving module, an AC plug-in module, an FPGA processing module, a differential protection module, a control output module and a wireless communication module. The FPGA processing module is respectively connected to the timing receiving module, the AC plug-in module, the differential protection module and the wireless communication module. Among them, the timing receiving module receives a unified timing signal of a GPS or wireless network. If the timing signal is an optical signal input, the timing electrical signal is output to the FPGA processing module after completing the photoelectric conversion; if the timing signal is an electrical signal input, it is directly output to the FPGA processing module. The AC plug-in module isolates and converts the voltage / current AC electrical quantity into a sampled analog quantity and then outputs it to the FPGA processing module. The FPGA processing module receives preset configuration parameters; analyzes the timing signal to obtain unified timing information, which includes synchronous sampling pulses and synchronous sampling moments; performs analog-to-digital conversion after receiving the sampled analog quantity, and obtains synchronous sampling data of the differential protection device 1 according to the synchronous sampling pulse; interconnects with the wireless communication module through the Ethernet interface, and interacts with other differential protection devices 2 to N through multi-terminal communication messages, and the communication messages include protocol stack messages and data messages; interconnects with the differential protection module through the local bus, and outputs differential data messages. The differential protection module sends preset configuration parameters to the FPGA processing module; at the same time, obtains the synchronous sampling data of each device in the differential data message, calculates and compares according to Kirchhoff's current theorem, and decides whether to send a differential control signal to the control output module. The differential protection module is connected to the control output module, and the control output module drives the external switch of the differential protection device 1 to open and close according to the differential control signal of the differential protection module. The wireless communication module exchanges communication messages with the FPGA processing module through the Ethernet interface, and adopts a fixed IP method to communicate the communication messages with other differential protection devices 2 to N through the wireless network.

[0027] The wireless multi-terminal differential protection device uses FPGA as its core, and utilizes the unique parallel data processing and delay controllable capabilities of FPGA to receive the configuration parameters of the differential protection module for the FPGA processing module; complete the timing signal analysis; according to the preset configuration parameters, realize the analog-to-digital conversion and synchronous sampling of the analog quantity sampled by the differential protection device 1, and package and send and receive and analyze each communication message; according to the synchronous sampling moment of the differential protection device 1, obtain the synchronous sampling data of other differential protection devices 2 to N at the same synchronous sampling moment, and package them together with the synchronous sampling data of the differential protection device 1 into a differential data message and output it to the differential protection module.

[0028] like Figure 2As shown, the FPGA processing module includes a time analysis module, an analog quantity acquisition module, a control processing module, a message multiplexing and sending module, a message receiving module, an Ethernet module and a data interaction module. The control processing module is connected to the time analysis module, the analog quantity acquisition module, the message multiplexing and sending module, the message receiving module and the data interaction module respectively, and the message multiplexing and sending module and the message receiving module are connected to the Ethernet module.

[0029] The timing analysis module analyzes the timing signal, triggers the synchronous sampling pulse based on the timing signal, and records the synchronous sampling moment.

[0030] The analog quantity acquisition module completes the synchronous sampling of analog quantities according to the preset configuration parameters and the synchronous sampling pulses to obtain the synchronous sampling data of the differential protection device 1 .

[0031] The data interaction module receives and analyzes the preset configuration parameters sent by the differential protection module to the FPGA processing module through the local bus, and forwards the output differential data message to the differential protection module.

[0032] The Ethernet module is used for encapsulating and parsing Ethernet messages, and converting the communication messages received from the message multiplexing and sending module into serial signals for transmission to the wireless communication module, or converting the serial signals output by the wireless communication module into communication messages for transmission to the message receiving module.

[0033] The message receiving module receives the communication message according to the preset configuration parameters, parses the data message to obtain the synchronous sampling data message of the differential protection device 2-N, and parses the protocol stack message to realize the protocol stack reply and response functions.

[0034] The message multiplexing sending module sends the protocol stack message according to the preset configuration parameters to realize the protocol stack request and heartbeat functions, and controls the output of the data message and the protocol stack message according to the priority.

[0035] The control processing module forms a sending data message composed of the synchronous sampling data and the synchronous sampling time of the differential protection device 1 and outputs it to the message multiplexing sending module; at the same time, it receives and caches the receiving data messages of other devices 2 to N, selects the synchronous sampling data of other devices 2 to N with the same synchronous sampling time according to the synchronous sampling time of device 1, and forms a differential data message with the synchronous sampling data of device 1, which is forwarded and output to the differential protection module through the data interaction module.

[0036] like Figure 3 As shown, the present invention discloses a wireless multi-terminal differential protection method based on FPGA, comprising the following steps:

[0037] Step 1: After the differential protection device 1 has completed parsing the preset configuration parameters, it completes the protocol stack link establishment with the differential protection devices 2 to N, monitors the link status, outputs an alarm if the link is broken, and re-establishes the link. Among them, the configuration parameters include the analog synchronous sampling frequency, the MAC address and IP address of the device Ethernet port. In addition, the FPGA realizes the protocol stack network communication, which can accurately control and reduce the message transmission delay.

[0038] Step 2: According to the preset configuration parameters, the timing signal is analyzed to trigger the synchronous sampling pulse, the synchronous sampling moment is recorded, and the synchronous sampling data of the differential protection device 1 is obtained according to the synchronous sampling pulse.

[0039] Step three: The synchronous sampling data and synchronous sampling time of the differential protection device 1 are combined into a sending data message, and transmitted to the differential protection devices 2 to N via the wireless communication network.

[0040] Step 4: The differential protection device 1 receives and buffers the received data messages from the differential protection devices 2-N at the same time.

[0041] Step 5: The differential protection device 1 selects the received data message at the same time of synchronous sampling of the differential protection devices 2 to N according to the synchronous sampling time, and forms a differential data message with the synchronous sampling data of the differential protection device 1. The FPGA selects the synchronous sampling data of the differential protection devices 1 to N at any time to form a differential data message, so as to realize real-time and high-speed data interaction between multi-terminal differential protection devices and improve the practicality and action timeliness of multi-terminal differential protection.

[0042] Step six: if the wireless communication link is normal, the differential data message is forwarded by the data interaction module to the differential protection module; otherwise, the differential data message is interrupted from being output to the differential protection module.

[0043] Step seven, the differential protection module obtains the synchronous sampling data of the differential protection devices 1 to N at any time according to the received differential data message, calculates and compares according to Kirchhoff's current theorem, determines whether a fault occurs, whether the fault is within the protection range or outside the protection range, and thus decides whether to output a differential control signal to the control output module to drive the external switch on this side to open and close control.

[0044] Step 8: Similarly, the differential protection devices 2 to N complete the opening and closing control of the differential protection switches of the devices on this side according to steps 1 to 7.

[0045] The present invention implements protocol stack network communication based on FPGA, which ensures that processing delay is fixed and controllable and reduces transmission delay to the greatest extent; at the same time, FPGA receives, analyzes and obtains synchronous sampling data of all devices to form differential data messages, making it possible to use wireless communication technology between protection devices to implement multi-terminal differential protection. The wireless multi-terminal differential protection device and method based on FPGA provided by the present invention have the advantages of convenient access, good adaptability and scalability, short construction period and convenient maintenance.

[0046] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A wireless multi-terminal differential protection method, performed by a single differential protection device, characterized in that: The following steps are involved: Parse the preset configuration parameters, complete the protocol stack link establishment with other differential protection devices according to the configuration parameter analysis results, and then monitor the link status. If the link is broken, output an alarm and re-establish the link; Analyze the timing signal according to the preset configuration parameters, generate synchronous sampling pulses and synchronous sampling moments, and obtain synchronous sampling data using the synchronous sampling pulses; The synchronous sampling data and the synchronous sampling time are combined into a sending data message, and transmitted to other differential protection devices via a wireless communication network; Receive and buffer received data messages from other differential protection devices; According to the synchronous sampling time, the received data message of the synchronous sampling time of other differential protection devices is selected, and the received data message is composed of the synchronous sampling data and the synchronous sampling data; If the wireless communication link is normal, the differential data message is forwarded to other differential protection devices; Receive differential data messages forwarded by other differential protection devices, obtain the synchronous sampling data of all differential protection devices at any time according to the received differential data messages, calculate and compare according to Kirchhoff's current theorem, and judge whether a fault occurs. If so, output differential control signals to drive the external switch on this side to open and close for control.

2. A wireless multi-terminal differential protection method according to claim 1, characterized in that: The protocol stack link building is implemented through FPGA.

3. A wireless multi-terminal differential protection method according to claim 1, characterized in that: The configuration parameters include the analog synchronous sampling frequency, the MAC address and IP address of the Ethernet port.

4. A wireless multi-terminal differential protection method according to claim 1, characterized in that: The sending data message is organized and sent by the FPGA processing module.

5. A wireless multi-terminal differential protection method according to claim 1, characterized in that: If the wireless communication link is abnormal, the differential data message processing process is interrupted, the preset configuration parameters are parsed, and the protocol stack link establishment process is completed with other differential protection devices according to the configuration parameter parsing results.

6. A wireless multi-terminal differential protection device, characterized in that: The wireless multi-terminal differential protection method according to any one of claims 1 to 5 comprises an FPGA processing module, wherein the FPGA processing module is respectively connected to a timing receiving module, an AC plug-in module, a differential protection module and a wireless communication module, wherein the timing receiving module outputs a received timing signal to the FPGA processing module, wherein the AC plug-in module isolates and converts the voltage / current AC electrical quantity into a sampled analog quantity and then outputs the result to the FPGA processing module, wherein the differential protection module sends preset configuration parameters to the FPGA processing module and obtains a differential data message sent by the FPGA processing module, wherein the wireless communication module exchanges communication messages with the FPGA processing module via an Ethernet interface, wherein the differential protection module is connected to a control output module, wherein the differential protection module outputs a differential control signal to the control output module, and wherein the control output module drives an external switch for separation and connection control.

7. A wireless multi-terminal differential protection device according to claim 6, characterized in that: The FPGA processing module includes a control processing module, which is respectively connected to a time synchronization and analysis module, an analog quantity acquisition module, a message multiplexing and sending module, a message receiving module and a data interaction module, and the message multiplexing and sending module and the message receiving module are connected to an Ethernet module.

8. The wireless multi-terminal differential protection device according to claim 6, characterized in that: The number of the differential protection devices is N, where N is an integer greater than or equal to 2. A single differential protection device is interconnected with other differential protection devices via the wireless communication module to perform multi-terminal communication message interaction.

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