CN110519016B - Three-in-one network data sending method based on real-time priority dynamic adjustment - Google Patents

Abstract

The invention provides a three-in-one network data sending method based on real-time priority dynamic adjustment, which is based on an FPGA chip and can be used in an electric power system, particularly in an application occasion where protective and automatic equipment in an intelligent substation share a port to send network data such as SV, GOOSE, MMS and the like. The method has high sending efficiency, flexible configuration and good portability, meets the release discreteness of SV data and the rapid release performance of GOOSE data, and can be also applied to similar applications in other fields.

Description

Three-in-one network data sending method based on real-time priority dynamic adjustment

Technical Field

The invention relates to the technical field of power communication, in particular to a three-in-one network data transmission method based on real-time priority dynamic adjustment.

Background

At present, the continuous progress of power electronic technology and communication technology has promoted the continuous development of relay protection technology, and national grid has proposed the protection device of new generation: the protection device is formed in situ. With the successful application of the on-site protection device in the intelligent substation test point and the maturity of related industry standards, the popularization and application of the on-site protection device are wider. The in-situ protection device adopts the design of miniaturization, high protection and low power consumption, realizes in-situ installation, and ensures the independence and the rapidity of main protection. In order to achieve the purpose, the device adopts a design of SV, GOOSE and MMS three-network-in-one common-port receiving and sending, and a total-station protection private network is constructed to realize information interaction among secondary equipment. Compared with the traditional SV, GOOSE and MMS single-port transmission, the three-in-one network improves the complexity in design and implementation, and puts higher requirements on the reliability of the work of the protection private network, the network transmission delay and the transmission discreteness.

Due to the fact that requirements for SV, GOOSE and MMS data transmission of the secondary equipment of the intelligent substation are different, deviation of discrete performance requirements for SV transmission is not more than +/-10 us, and the current mainstream design is finished by using an FPGA chip; when GOOSE data is sent, the data is required to be sent as soon as possible when the data is shifted, generally, the sending delay requirement is less than 1ms, and the data is sent according to the rhythm of GOOSE shift burst, the data is sent at the rhythm of 2ms, 4ms, 8ms and 5000ms after the shifting, and 5000ms is the last stable heartbeat message; when an MMS message is sent, because MMS is based on TCP/IP protocol, the network connection has a super-time retransmission mechanism, the sensitivity to time is not as high as SV and GOOSE, but the sending delay generally causes the reduction of the transmission efficiency of MMS data. When three networks are combined to one port for transmission, the release discreteness of the SV and the transmission delay of the GOOSE are ensured to be smaller and better; the requirement for MMS is efficient transmission on the premise of meeting SV and GOOSE delivery performance. The current three-in-one network transmission mechanism mainly ensures that an SV is preferentially transmitted, after the SV is transmitted, whether GOOSE or MMS data exists in a buffer area is scanned regularly, and when the GOOSE or MMS data exists, the data is read and transmitted, and one frame is transmitted every time, so that no data conflict exists. The mechanism has the advantages of simple design and implementation, easy program maintenance and the disadvantages of low efficiency of transmission and poor adaptability, and cannot cope with complex application scenarios, for example, under the condition that a plurality of GOOSE control blocks need to be transmitted, larger transmission delay may exist and the transmission requirement is not met.

Disclosure of Invention

The invention aims to provide a three-in-one data transmission method based on real-time priority dynamic adjustment, which aims to solve the problems of low transmission efficiency and poor adaptability of three-in-one data in the prior art, improve the data transmission efficiency and adapt to different application scenes.

In order to achieve the technical purpose, the invention provides a three-in-one network data transmission method based on real-time priority dynamic adjustment, which comprises the following operations:

analyzing the configuration file to obtain relevant configuration parameters for data transmission;

writing SV, GOOSE and MMS framing data into various types of buffer areas according to related configuration parameters, and determining the priority of the GOOSE and MMS data through a resident timer;

switching to an output bus of an SV buffer area when an SV sends a time window, and switching to an output bus of a GOOSE buffer area and an MMS buffer area when a non-SV sends a time window;

for SV data transmission, determining whether an SV transmission time window mark is valid or not through an SV transmission interval timer, waiting for SV data when the window mark is valid, and transmitting the SV data to a transmission buffer area after the SV data arrives;

for the sending of GOOSE and MMS data, polling and scanning a buffer area, comparing priorities to screen out data to be sent, judging whether a current SV sending gap can be inserted or not through a time scale register, and transmitting the data to the sending buffer area when the current SV sending gap can be inserted;

and sending the data in the sending buffer to the target module.

Preferably, the SV framing data writing buffer operates as follows:

according to the configured SV sending period, the FPGA equally divides the SV to generate sampling pulses through synchronous or punctual second pulses;

sampling and framing at the sampling pulse moment according to the configuration template of the SV, writing data into an SV buffer area, positioning an effective mark of the buffer area, and simultaneously transmitting SV length parameter information.

Preferably, when the timer reaches the overflow value, the priority of GOOSE or MMS data is raised.

Preferably, the SV data is transmitted specifically as follows:

starting an SV sending interval timer, and setting an SV sending window mark to be effective when the SV sending interval timer overflows;

and after the validity of the SV sending window is detected, waiting for the next frame of SV data and clearing the valid mark of the SV sending window, and when the next frame of SV data arrives, resetting the SV sending interval timer and starting to count again.

Preferably, the overflow value of the SV transmission interval timer is set by a user.

Preferably, the screening of the data to be sent by comparing the priorities specifically operates as follows:

polling a GOOSE data buffer area and an MMS data buffer area, and latching the parameters of the priority, the residence time, the length, the suspension mark and the buffer area number of the buffer area to a temporary register when the buffer area needing to send data is scanned;

comparing the priority of the temporary register with that of the priority register, and updating each data in the temporary register to the priority register, the residence time latch register, the length register and the buffer area number register when the priority stored in the temporary register is higher than that of the priority register;

when the priority stored in the temporary register is equal to the value in the priority register, comparing the residence time, and if the residence time value stored in the temporary register is large, updating the priority register, the residence time latch register, the length register and the buffer area number register, otherwise, not updating;

when the priority stored in the temporary register is smaller than the priority register, the priority level register is not updated.

Preferably, the specific operation of determining whether the current SV transmission gap can be inserted by the time scale register is:

calculating the transmission occupation time of the data to be transmitted according to the length of the data to be transmitted, adding the time and the data value in the time scale register, and judging whether the numerical value enters an SV transmission time window, wherein if the numerical value enters the SV transmission time window, the transmission condition is not met; if not entering SV sending time window, the data corresponding to the buffer area number is transmitted to the sending buffer area, and the added result is updated to the time scale register.

Preferably, the method further includes preemptively sending data, and specifically the following operations are performed:

when polling selects a certain GOOSE data or MMS data according to the current priority, the data needs to be transmitted from the corresponding buffer area to the sending buffer area, and if the data with the priority higher than the currently selected data comes during the period, the sending of the current data is interrupted, the sending parameters are recovered, and the high-priority data is polled and scanned again;

when the GOOSE data of the same control block is shifted, the corresponding heartbeat frame is not sent or is written into the sending buffer area, and then the current shifted data can preempt the sending of the GOOSE heartbeat data of the same control block.

The effect provided in the summary of the invention is only the effect of the embodiment, not all the effects of the invention, and one of the above technical solutions has the following advantages or beneficial effects:

compared with the prior art, the invention is based on the FPGA chip, can be used in an electric power system, particularly in an application occasion where protective and automatic equipment in an intelligent substation transmits network data such as SV, GOOSE, MMS and the like in a common port, and realizes the common port transmission of various types of network data by configuring and dividing multiple priorities, dynamically adjusting the priorities, and reversing and preempting a transmission queue in real time. The method has high sending efficiency, flexible configuration and good portability, meets the release discreteness of SV data and the rapid release performance of GOOSE data, and can be also applied to similar applications in other fields.

Drawings

Fig. 1 is a schematic diagram of a triple play module inside an FPGA according to an embodiment of the present invention;

fig. 2 is a flowchart of a dynamic scheduling logic for transmitting FPGA network data according to an embodiment of the present invention.

Detailed Description

In order to clearly explain the technical features of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings. The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. It should be noted that the components illustrated in the figures are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and procedures are omitted so as to not unnecessarily limit the invention.

The following describes in detail a triple-play data transmission method based on real-time priority dynamic adjustment according to an embodiment of the present invention with reference to the accompanying drawings.

As shown in fig. 1 and 2, an embodiment of the present invention discloses a three-in-one data transmission method based on real-time priority dynamic adjustment, where the method includes the following operations:

analyzing the configuration file to obtain relevant configuration parameters for data transmission;

writing SV, GOOSE and MMS framing data into various types of buffer areas according to related configuration parameters, and determining the priority of the GOOSE and MMS data through a resident timer;

switching to an output bus of an SV buffer area when an SV sends a time window, and switching to an output bus of a GOOSE buffer area and an MMS buffer area when a non-SV sends a time window;

for SV data transmission, determining whether an SV transmission time window mark is valid or not through an SV transmission interval timer, waiting for SV data when the window mark is valid, and transmitting the SV data to a transmission buffer area after the SV data arrives;

for the sending of GOOSE and MMS data, polling and scanning a buffer area, comparing priorities to screen out data to be sent, judging whether a current SV sending gap can be inserted or not through a time scale register, and transmitting the data to the sending buffer area when the current SV sending gap can be inserted;

and sending the data in the sending buffer to the target module.

The real-time priority dynamic adjustment mechanism of the embodiment of the invention is as follows:

the SV data is the highest in the sending priority in the three-network data, and in order to ensure the stability of the transmission delay and the release discreteness of the SV data, the SV sending time is estimated according to the characteristic of stable SV sending interval, an SV sending time window is opened (configurable) 10us before the SV sending time, SV network data is waited to be sent, and after the SV is sent, the non-SV sending time window is entered, and GOOSE and MMS data are inserted for sending.

And analyzing the configuration file, acquiring configuration parameters related to a sending module, configuring the three-in-one sending function according to system requirements, and enabling SV, GOOSE and MMS data sending to be combinable and configurable so as to enable one or more of the SV, GOOSE and MMS data sending. The basic priority of the GOOSE and MMS sending data is configured, namely different GOOSE control block priorities can be configured, and when heartbeat data of a plurality of GOOSE control blocks are effective at the same time, data frames with high basic priority are sent preferentially. And configuring time parameters related to transmission, including time parameters of priority inversion, GOOSE data transmission rhythm and SV transmission time window allowance.

And writing SV, GOOSE and MMS framing data into a sending buffer area through the FPGA.

Writing SV data into an SV buffer area, equally dividing by an FPGA through synchronous or punctual second pulses according to a configured SV sending period (usually 250us) to generate sampling pulses, sampling and framing at the sampling pulse moment according to a configuration template of the SV, writing the data into the SV buffer area, positioning an effective mark of the buffer area, and simultaneously transmitting parameter information such as SV length and the like.

And the GOOSE data is written into the GOOSE buffer area, so that the common network transmission of a plurality of GOOSE control blocks can be realized. By utilizing the parallel processing characteristic of the FPGA, the framing and writing buffer area operation of each GOOSE control block is mutually independent. The FPGA detects GOOSE data arrays transmitted by the CPU at intervals of sampling time, when data change is detected, the GOOSE data arrays are mapped to corresponding GOOSE control blocks according to configuration information, the corresponding control blocks are controlled to shift and group frames, StNum parameters are increased by 1, SqNum parameters return to 0, parameters such as GOOSE length, GOOSE types (shift, burst and heartbeat), interrupt marks and the like are transmitted, and each control block writes the framing data into a corresponding GOOSE data buffer area.

And when the GOOSE framing is finished, starting two timers, wherein one timer is a rhythm control timer and is used for framing next frame data of the GOOSE, and the other timer is a resident timer, when the resident timer reaches an overflow value, the priority of the current GOOSE data type is promoted, so that the aim of preemptive sending is fulfilled, the overflow value of the resident timer can be configured into 2, when the counter reaches a larger overflow value, the priority is promoted again, and when the data in the GOOSE buffer area is taken away, the corresponding resident timer is reset. When the GOOSE data changes, the rhythm control timer directly overflows, when the GOOSE data does not change, the rhythm control timer dynamically loads a corresponding configuration value according to the value of the currently sent SqNum to serve as an overflow value, and the resident timer always dynamically loads the configuration value according to the value of the SqNum to serve as the overflow value. Each GOOSE control block may be classified into the following priorities according to the GOOSE type and the resident timer:

the priority may also be GOOSE shift (emergency), GOOSE burst (emergency), or GOOSE heartbeat data (emergency) when the overflow value configured by the resident timer is 2.

The order of priority can be configured, and is usually set as GOOSE shift (urgent) > GOOSE burst (urgent) > GOOSE heartbeat data (urgent) > GOOSE shift (high) > GOOSE heartbeat data (high) > GOOSE shift (normal) > GOOSE heartbeat data (high) > GOOSE burst (normal) > GOOSE heartbeat data (normal).

And writing MMS data into an MMS buffer area, transmitting MMS data through a data bus of the CPU and the FPGA, arranging an FIFO buffer area at the FPGA side, and transmitting the frame idle number in the FIFO buffer area by the MMS module of the FPGA through handshaking with the CPU to control the MMS data needing to be written. Although MMS has retransmission mechanism, in order to improve transmission efficiency, similar to GOOSE data processing, a resident timer is also designed in each frame data buffer in the MMS buffer, and priority inversion also occurs when the timer overflows, so that the data is sent in advance.

And the network data sending and scheduling module switches the SV buffer and output buses of data buffers of other GOOSE and MMS according to whether the current SV sending time window is the SV. In a non-time window, the network data sending and scheduling module switches output buses of the GOOSE buffer area and the MMS buffer area by polling the data buffer areas of the GOOSE buffer area and the MMS buffer area, and plays a role of switching the buses of the multi-way switch by the control of the network data sending and scheduling module.

In the process of data transmission of three-in-one network, according to actual requirements, whether SV transmission is enabled or not can be determined through configuration, when SV transmission is not enabled, GOOSE and MMS data are transmitted without waiting for a non-SV transmission time window, whether frames to be transmitted can be inserted into the time window or not is not calculated, and only priority ratio comparison is needed for transmission; when SV sending is configured, before SV sending configuration parameters are completed, GOOSE and MMS data are scanned and sent, the sending functions of the GOOSE and the MMS are not influenced, the system operates according to a mechanism which does not enable the SV function at the moment, after SV sending initialization is completed, an initialization module gives an SV sending window effective signal once, and after a current sending task is idle, a program waits for a first frame of SV data to be written into a sending buffer area.

For SV data transmission, after data in an SV buffer is valid for the first time, an SV transmission interval timer is started, when the SV transmission interval timer overflows, an SV transmission window flag is set to be valid, the overflow value of the SV transmission interval timer is generally configured to be 240us, after the SV transmission window is detected to be valid, a control program waits for next frame of SV data and clears the SV transmission window valid flag, when the next frame of SV data arrives, the SV transmission interval timer is reset and starts to count again, no accumulated error exists in an SV transmission window, and the stability of SV transmission is guaranteed preferentially.

For the sending of GOOSE and MMS data, in order to ensure that the GOOSE and MMS data can be normally inserted into the time gap between two SV frames without affecting the sending of SV, a time scale register is created and used for calculating whether the GOOSE and MMS data to be sent have reliable sending time. And resetting the time scale register when waiting for SV transmission each time, calculating the time required by the data transmission according to the frame length of the SV data after the SV data is transmitted, writing the time into the time scale register, entering a GOOSE and MMS data transmission state, and judging whether data and the like are to be transmitted in the GOOSE and MMS data areas. Polling GOOSE data buffer and MMS data buffer, when scanning the buffer needed to send data, latching the buffer priority, dwell time, length, hang-up mark, buffer number and other parameters to the temporary register.

Skipping the buffer area to continue polling scanning when the suspension mark of the buffer area is effective; when the suspension mark is invalid, the temporary register is compared with the priority of the priority register, and when the priority stored in the temporary register is higher than the priority register, all data in the temporary register are updated to the priority register, the residence time latch register, the length register and the buffer area number register; when the priority stored in the temporary register is equal to the value in the priority register, comparing the residence time, if the residence time value stored in the temporary register is large, updating the priority register, otherwise not updating; when the priority stored in the temporary register is smaller than the priority register, the priority level register is not updated. After all the registers are polled in sequence, the data stored in the buffer area number register is the buffer area to be sent selected at the current moment.

Whether the data to be transmitted screened after being screened can be inserted into the current SV transmission gap or not is judged by the polling scanning priority ratio, the time scale register is updated after the data is selected, and if the value of the SV transmission interval timer is greater than that of the time scale register, the value of the SV transmission interval timer is updated to the time scale register, otherwise, the SV transmission interval timer is not updated. After updating, calculating the transmission occupied time according to the length of the data to be transmitted, adding the time and the data value in the time scale register, judging whether the value enters an SV transmission time window, if so, not meeting the transmission condition, placing the data in the buffer area in a suspension mark, not transmitting the data in the SV transmission interval in the current round, improving the transmission efficiency, resetting the suspension mark when the SV data is transmitted, if not, transmitting the data corresponding to the buffer area number to the transmission buffer area, updating the addition result to the time scale register, and starting the polling transmission of the next frame data.

When GOOSE or MMS data cannot be selected for transmission within a certain time due to low priority, the priority inversion mechanism will increase the priority and transmit the data preferentially to ensure the transmission performance. When the overflow value of the timer for retaining GOOSE shift data is configured to 300us, and when GOOSE shift data 300us is still not transmitted, the priority of the shift GOOSE is increased, so as to ensure the preferential transmission. When the overflow value of the timer for the GOOSE heartbeat data is configured to be 1s, and when the GOOSE heartbeat data is not sent 1s after the normal heartbeat, the priority of the heartbeat data is increased, and the GOOSE heartbeat data is guaranteed to be sent preferentially. The priority inversion design method for other data types is the same as described above.

In order to make the transmission more efficient, the mechanism sets a preemptive transmission mechanism, the preemptive transmission is only applicable to GOOSE and MMS data, and the SV data transmission cannot be interrupted, which includes the following two modes:

when polling selects a certain GOOSE data or MMS data according to the current priority, the data needs to be transmitted from the corresponding buffer area to the sending buffer area, during the period, if the arrival of the data with higher priority than the currently selected data is monitored, the sending of the current data is interrupted, the sending parameters are recovered, the high-priority data is polled and scanned again, and the preemptive sending can ensure the sending delay of the high-priority data;

because the GOOSE data displacement occurs asynchronously, the GOOSE data displacement can be performed immediately after one time of GOOSE heartbeat data, in this case, the last GOOSE heartbeat frame can influence the sending delay of the GOOSE displacement data, and in order to improve the sending performance and the sending efficiency, when the GOOSE data of the same control block is displaced, the corresponding heartbeat frame is not sent or is written into a sending buffer area, and then the current displacement data can preempt the GOOSE heartbeat data sending of the same control block.

And finally, when valid data exist in the sending buffer area, the MAC module sequentially reads the data in the sending buffer area, calculates CRC check, and sends the data to the PHY chip or the optical module through the SEDER to finish the three-in-one frame sending.

The embodiment of the invention is based on the FPGA chip, can be used for the application occasions of the protection and automation equipment in the power system, particularly the intelligent substation, for transmitting the network data such as SV, GOOSE, MMS and the like in a common port, and realizes the common port transmission of various types of network data by configuring and dividing multiple priorities, dynamically adjusting the priorities and reversing and preempting the transmission queue in real time. The method has high sending efficiency, flexible configuration and good portability, meets the release discreteness of SV data and the rapid release performance of GOOSE data, and can be also applied to similar applications in other fields.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (7)

1. A three-in-one network data transmission method based on real-time priority dynamic adjustment is characterized by comprising the following operations:

analyzing the configuration file to obtain relevant configuration parameters for data transmission;

writing SV, GOOSE and MMS framing data into various types of buffer areas according to related configuration parameters, and determining the priority of the GOOSE and MMS data through a resident timer;

switching to an output bus of an SV buffer area when an SV sends a time window, and switching to an output bus of a GOOSE buffer area and an MMS buffer area when a non-SV sends a time window;

for SV data transmission, determining whether an SV transmission time window mark is valid or not through an SV transmission interval timer, waiting for SV data when the window mark is valid, and transmitting the SV data to a transmission buffer area after the SV data arrives;

for the sending of GOOSE and MMS data, polling and scanning a buffer area, comparing priorities to screen out data to be sent, judging whether a current SV sending gap can be inserted or not through a time scale register, and transmitting the data to the sending buffer area when the current SV sending gap can be inserted;

sending the data in the sending buffer area to a target module;

the specific operation of screening the data to be sent by comparing the priorities is as follows:

polling a GOOSE data buffer area and an MMS data buffer area, and latching the parameters of the priority, the residence time, the length, the suspension mark and the buffer area number of the buffer area to a temporary register when the buffer area needing to send data is scanned;

comparing the priority of the temporary register with that of the priority register, and updating each data in the temporary register to the priority register, the residence time latch register, the length register and the buffer area number register when the priority stored in the temporary register is higher than that of the priority register;

when the priority stored in the temporary register is equal to the value in the priority register, comparing the residence time, and if the residence time value stored in the temporary register is large, updating the priority register, the residence time latch register, the length register and the buffer area number register, otherwise, not updating;

when the priority stored in the temporary register is smaller than the priority register, the priority level register is not updated.

2. The method as claimed in claim 1, wherein the SV framing data writing buffer is operated as follows:

according to the configured SV sending period, the FPGA equally divides the SV to generate sampling pulses through synchronous or punctual second pulses;

sampling and framing at the sampling pulse moment according to the configuration template of the SV, writing data into an SV buffer area, positioning an effective mark of the buffer area, and simultaneously transmitting SV length parameter information.

3. The method as claimed in claim 1, wherein the priority of GOOSE or MMS data is raised when the timer reaches an overflow value.

4. The method as claimed in claim 1, wherein the SV data is transmitted according to the following specific operations:

starting an SV sending interval timer, and setting an SV sending window mark to be effective when the SV sending interval timer overflows;

and after the validity of the SV sending window is detected, waiting for the next frame of SV data and clearing the valid mark of the SV sending window, and when the next frame of SV data arrives, resetting the SV sending interval timer and starting to count again.

5. The method as claimed in claim 4, wherein the overflow value of the SV transmission interval timer is set by a user.

6. The method as claimed in claim 1, wherein the operation of determining whether the current SV transmission gap can be inserted by the time scale register is specifically:

calculating the transmission occupation time of the data to be transmitted according to the length of the data to be transmitted, adding the time and the data value in the time scale register, and judging whether the numerical value enters an SV transmission time window, wherein if the numerical value enters the SV transmission time window, the transmission condition is not met; if not entering SV sending time window, the data corresponding to the buffer area number is transmitted to the sending buffer area, and the added result is updated to the time scale register.

7. The method for sending triple-play data based on real-time priority dynamic adjustment according to claim 1, further comprising preemptive data sending, specifically operating as follows:

when polling selects a certain GOOSE data or MMS data according to the current priority, the data needs to be transmitted from the corresponding buffer area to the sending buffer area, and if the data with the priority higher than the currently selected data comes during the period, the sending of the current data is interrupted, the sending parameters are recovered, and the high-priority data is polled and scanned again;

when the GOOSE data of the same control block is shifted, the corresponding heartbeat frame is not sent or is written into the sending buffer area, and then the current shifted data can preempt the sending of the GOOSE heartbeat data of the same control block.

Images