A method, system, and electronic equipment for determining wireless communication delay in intelligent substations.

Abstract

This invention provides a method, system, and electronic device for determining wireless communication delay in intelligent substations, belonging to the field of wireless communication. The method includes: obtaining a deterministic delay based on the message forwarding delay of each router, the message processing and parsing delay of each intelligent electronic device, and the message propagation delay of each wireless channel; determining the transmission delay of data packets based on the data frame length corresponding to the data packets and the channel bandwidth; determining the total length of queued messages at each router using a Monte Carlo method based on the message queuing model at each router; determining the queuing delay for forwarding messages after they arrive at the router based on the total length of queued messages at the router, the load rate, and the data forwarding rate; obtaining a random delay based on the transmission delay of each data packet and the queuing delay for forwarding messages after they arrive at each router; and determining the wireless communication delay of the intelligent substation based on the deterministic and random delays. This invention can accurately calculate the wireless communication delay of intelligent substations.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and in particular to a method, system, and electronic device for determining wireless communication delay in intelligent substations. Background Technology

[0002] As a typical cyber-physical system, a smart substation integrates its physical and information systems. Information transmission and reception are both achieved through networks; therefore, network performance directly impacts the normal operation of the smart substation's cyber-physical system. Currently, smart substations mostly adopt a "three-layer, two-network" structure: station control layer, bay layer, process layer, process layer network, and station control layer network.

[0003] The backbone network of a smart substation is mainly composed of fiber optic networks. The advantages of fiber optics in terms of transmission speed and bandwidth effectively ensure the efficient and stable transmission of large amounts of data within the smart substation network. However, fiber optic lines also have some drawbacks, such as brittleness, poor mechanical strength, high laying costs, and inflexible coupling. Wireless communication technology can be used for data message transmission in smart substations. Its advantages include rapid deployment, convenient and flexible access to various services within the substation, lower maintenance costs, and the ability to achieve seamless communication coverage. Currently, wireless communication technology has been successfully applied in wireless temperature measurement and wireless monitoring in smart substations. However, the wireless transmission of network messages in smart substations is still under research in the area of ​​wireless networking of equipment.

[0004] Communication latency is an intuitive data point that characterizes the real-time performance of an information network. The greater the communication latency, the worse the real-time performance of the network. An important characteristic of information networks is that communication latency is uncertain. Currently, there is a lack of characteristic descriptions of latency in wireless communication systems for smart substations.

[0005] Therefore, there is an urgent need for a method to characterize the wireless communication delay of smart substations, as a basis for analyzing the impact of communication delay on the safe and reliable operation of wireless smart substations. Summary of the Invention

[0006] The purpose of this invention is to provide a method, system, and electronic device for determining the wireless communication delay of a smart substation, which can accurately calculate the wireless communication delay of a smart substation.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A method for determining the wireless communication delay in a smart substation includes:

[0009] The system acquires the packet forwarding latency of each router, the packet processing and parsing latency of each intelligent electronic device, the packet propagation latency of each wireless channel, the number of data packets, the data frame length corresponding to each data packet, the channel bandwidth, the load rate of each router, and the data forwarding rate of each router. During communication in the intelligent substation, packets are forwarded by multiple routers, processed and parsed by multiple intelligent electronic devices, and transmitted through multiple wireless channels. Each wireless channel includes a receiver and a transmitter. Packets are encapsulated into data packets during communication, and data packets are encapsulated into data frames during communication.

[0010] The deterministic delay is obtained based on the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, and the packet propagation delay of each wireless channel.

[0011] For any data packet, the transmission delay of the data packet is determined based on the data frame length corresponding to the data packet and the channel bandwidth;

[0012] Based on the packet queuing model at each router, the Monte Carlo method is used to determine the total length of the queued packets at each router; the packet queuing model at each router is determined in advance according to the type of packets forwarded by each router.

[0013] For any given router, the queuing delay for forwarding a packet after it arrives at the router is determined based on the total length of the queued packets at the router, the router's load rate, and the router's data forwarding rate.

[0014] Random delay is obtained by considering the transmission delay of each data packet and the queuing delay for forwarding the message after it arrives at each router.

[0015] The wireless communication delay of the smart substation is determined based on the deterministic delay and the random delay.

[0016] Optionally, the deterministic delay can be calculated using the following formula:

[0017] τ C =∑ i∈R τ r (i)+∑ j∈D τ m (j)+∑ k∈L τ w (k);

[0018] Where, τ C For deterministic delay, R is the number of routers, τ r (i) represents the packet forwarding delay of router i, D represents the number of smart electronic devices, and τ m (j) represents the message processing and parsing delay of intelligent electronic device j, L represents the number of wireless channels, and τ w(k) represents the message propagation delay of wireless channel k.

[0019] Optionally, the transmission delay of data packet l can be calculated using the following formula:

[0020]

[0021] Where, τ t (l) represents the transmission delay of data packet l, L M Let L be the length of the data frame corresponding to data packet l, and B be the channel bandwidth.

[0022] Optionally, based on the packet queuing model at each router, the Monte Carlo method is used to determine the total length of queued packets at each router, specifically including:

[0023] For any given router, determine the queuing probability of packets at that router based on the packet queuing model at that router;

[0024] Based on the queuing probability of packets at the router, the probability distribution of the total length of queued packets at the router is determined using the Monte Carlo method.

[0025] The total length of the queued packets at the router is determined based on the probability distribution of the total length of the queued packets.

[0026] Optionally, the packet queuing model at each router is an M / M / 1 queuing model.

[0027] Optionally, the queuing delay for forwarding a packet after it arrives at router i can be calculated using the following formula:

[0028]

[0029] Where, τ q (i) is the queuing delay for forwarding a message after it arrives at router i, L q (E q (i) represents the total length of the queued packets at router i, E q (i) represents the packet queuing model at the router, β r (i) represents the load rate of router i, v r (i) represents the data forwarding rate of router i.

[0030] Optionally, the randomness delay can be calculated using the following formula:

[0031]

[0032] Where, τ S For random delay, K is the number of data packets, τ t (l) represents the transmission delay of data packet l, R represents the number of routers, and τq (i) is the queuing delay for forwarding a message after it arrives at router i.

[0033] To achieve the above objectives, the present invention also provides the following solution:

[0034] A smart substation wireless communication delay determination system includes:

[0035] The data acquisition unit is used to acquire the packet forwarding delay of each router, the packet processing and parsing delay of each intelligent electronic device, the packet propagation delay of each wireless channel, the number of data packets, the data frame length corresponding to each data packet, the channel bandwidth, the load rate of each router, and the data forwarding rate of each router. In the communication process of the intelligent substation, the packets are forwarded by multiple routers, processed and parsed by multiple intelligent electronic devices, and transmitted through multiple wireless channels. Each wireless channel includes a receiver and a transmitter. The packets are encapsulated into data packets during the communication process, and the data packets are encapsulated into data frames during the communication process.

[0036] A deterministic delay determination unit, connected to the data acquisition unit, is used to obtain the deterministic delay based on the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, and the packet propagation delay of each wireless channel.

[0037] A transmission delay determination unit, connected to the data acquisition unit, is used to determine the transmission delay of any data packet based on the data frame length corresponding to the data packet and the channel bandwidth.

[0038] The queuing message determination unit, connected to the data acquisition unit, is used to determine the total length of the queued messages at each router using the Monte Carlo method based on the message queuing model at each router; the message queuing model at each router is determined in advance according to the type of messages forwarded by each router.

[0039] The queuing delay determination unit, connected to the queuing packet determination unit, is used to determine the queuing delay for forwarding a packet after it arrives at the router, based on the total length of the queued packets at the router, the load rate of the router, and the data forwarding rate of the router, for any given router.

[0040] The randomness delay determination unit is connected to the transmission delay determination unit and the queuing delay determination unit respectively, and is used to obtain the randomness delay based on the transmission delay of each data packet and the queuing delay after the message arrives at each router for forwarding.

[0041] A communication delay determination unit is connected to both the deterministic delay determination unit and the random delay determination unit, and is used to determine the wireless communication delay of the smart substation based on the deterministic delay and the random delay.

[0042] To achieve the above objectives, the present invention also provides the following solution:

[0043] An electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor runs the computer program to enable the electronic device to perform the above-described method for determining the wireless communication delay in a smart substation.

[0044] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0045] This invention divides the communication delay of wireless intelligent substations into deterministic delay and random delay. Based on the packet queuing model at each router, the Monte Carlo method is used to determine the total length of the queued packets at each router. Then, based on the total length of the queued packets at the router, the load rate, and the data forwarding rate, the queuing delay for forwarding packets after they arrive at the router is determined. Furthermore, based on the transmission delay of each data packet and the queuing delay for forwarding packets after they arrive at each router, the random delay is obtained. The random delay is quantified and analyzed, and combined with the deterministic delay, the communication delay of packets in the wireless intelligent substation can be accurately calculated. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of the method for determining wireless communication delay in intelligent substations according to the present invention;

[0048] Figure 2 A schematic diagram illustrating the process of determining the random distribution characteristics of communication delay;

[0049] Figure 3 A schematic diagram of the frame format of GOOSE and SV messages;

[0050] Figure 4 This is a network topology diagram of a wireless intelligent substation;

[0051] Figure 5 This is a node model diagram of intelligent devices within the interval;

[0052] Figure 6 A latency statistics chart for smart devices;

[0053] Figure 7 This is a histogram showing the frequency distribution of time delay.

[0054] Figure 8 A schematic diagram of a system for determining wireless communication delay in smart substations.

[0055] Symbol explanation:

[0056] Data acquisition unit-1, deterministic delay determination unit-2, transmission delay determination unit-3, queued message determination unit-4, queuing delay determination unit-5, random delay determination unit-6, communication delay determination unit-7. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] The purpose of this invention is to provide a method, system, and electronic device for determining wireless communication delay in intelligent substations. It fully considers the delay caused by network devices, wireless channels, and message parsing during the transmission of information flow within the intelligent substation, and studies the characteristics of devices and messages during wireless communication to ensure the real-time performance and reliability of information communication in intelligent substations.

[0059] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] Since the wireless communication delay of a smart substation has random characteristics, this invention divides the wireless communication delay of the information flow in a smart substation into deterministic delay and random delay, and calculates the deterministic delay and random delay respectively.

[0061] Example 1

[0062] like Figure 1 As shown in the figure, this embodiment provides a method for determining the wireless communication delay of a smart substation, including:

[0063] S1: Obtain the packet forwarding latency of each router, the packet processing and parsing latency of each smart electronic device, the packet propagation latency of each wireless channel, the number of data packets, the data frame length corresponding to each data packet, the channel bandwidth, the load rate of each router, and the data forwarding rate of each router.

[0064] In the communication process of a smart substation, messages are forwarded by multiple routers, processed and parsed by multiple smart electronic devices, and transmitted through multiple wireless channels. Each wireless channel includes a receiver and a transmitter. Messages are encapsulated into data packets during communication, and data packets are encapsulated into data frames during communication.

[0065] S2: Based on the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, and the packet propagation delay of each wireless channel, the deterministic delay is obtained:

[0066] τ C =∑ i∈R τ r (i)+∑ j∈D τ m (j)+∑ k∈L τ w (k);

[0067] Where, τ C For deterministic delay, R is the number of routers, τ r (i) represents the packet forwarding delay of router i, i.e., the delay incurred when a packet is forwarded by router i, D is the number of intelligent electronic devices, and τ m (j) represents the message processing and parsing delay of intelligent electronic device j, i.e., the delay in which intelligent electronic device j processes and parses messages, L is the number of wireless channels, and τ w (k) represents the message propagation delay of wireless channel k, i.e., the propagation delay of the message between the receiver and the transmitter.

[0068] In this embodiment, the delay of a router forwarding a packet once is considered as a first constant β, where β = 12μs. Therefore, the packet forwarding delay of router i is: τ r (i) = R·β.

[0069] If we consider the delay in message processing and parsing by a smart electronic device as a second constant δ, where δ = 20 μs, then the message processing and parsing delay of smart electronic device j is: τ w (j)=D·δ.

[0070] If the speed of electromagnetic waves in air is c, then the propagation delay of the message between the receiver and the transmitter is: Where, x k This refers to the distance between the receiver and the transmitter.

[0071] S3: For any data packet, determine the transmission delay of the data packet based on the data frame length corresponding to the data packet and the channel bandwidth. Specifically, the transmission delay of data packet l is calculated using the following formula:

[0072]

[0073] Where, τ t (l) represents the transmission delay of data packet l, mainly referring to the time required for the host or router to send the data frame, that is, the time required from the first bit of the data to the last bit being sent. M Let B be the length of the data frame corresponding to data packet l, which is the length of the transmitted network data packet plus the frame header. The frame header length is related to different protocols. Let B be the channel bandwidth of the wireless communication channel. In this embodiment, Shannon's theorem is introduced to calculate the channel bandwidth:

[0074]

[0075] Where C is the maximum transmission rate of the channel, P S P is the average power of the signal. n This represents noise power.

[0076] S4: Based on the packet queuing model at each router, the Monte Carlo method is used to determine the total length of queued packets at each router. The packet queuing model at each router is pre-determined according to the types of packets forwarded by each router.

[0077] Specifically, (1) for any router, the queuing probability of packets at the router is determined according to the packet queuing model at the router. In smart substations, GOOSE and SV packets can be mainly divided into three types: periodic packets, random packets, and burst packets. This invention regards the packet queuing model at the router as an M / M / 1 model.

[0078] The data stream arriving with random messages is considered a Poisson stream, and the queuing probability is:

[0079]

[0080] P n =(1-ρ)ρ n (n = 0, 1, 2…);

[0081] Where ρ is the number of packets forwarded per unit time, λ is the distribution parameter of packet arrival, μ is the distribution parameter of packet after forwarding, and P n Let n be the probability that there are n messages in the queue, where n is the number of messages waiting in the queue, and the value of n is a random integer.

[0082] The model of the burst message can be regarded as a mixed model of the OFF state of the Poisson distribution and the ON state of the Pareto distribution. In the ON state, messages are generated at a constant rate, and in the OFF state, no messages are generated. The probability distribution model is established by controlling the time of the ON state and the OFF state. The Pareto part queuing probability is as follows:

[0083]

[0084] Among them, f is the rate of generating messages, f = 100 us / message, k (0 < k < t) is the shape parameter of the Poisson distribution, usually set as the minimum time interval between adjacent messages, k = 0.512 ms, α (α > 1) is the shape parameter of the Pareto distribution, representing its tail characteristics, α = 1.1.

[0085] (2) According to the queuing probability of the messages at the router, the Monte Carlo method is used to determine the probability distribution of the total length of the queued messages at the router.

[0086]

[0087]

[0088]

[0089] Among them, Υ is the total length of the queued messages at router i, L q (m) is the length of the message to be forwarded at the m-th router, P(Υ) is the preliminary probability distribution of Υ, and it is related to the message queuing model E q (i). Normalize all P(Υ) to obtain the probability distribution of the length of the messages queued at the router once.

[0090] (3) According to the probability distribution of the total length of the queued messages, determine the total length of the queued messages at the router.

[0091] S5: For any router, according to the total length of the queued messages at the router, the load rate of the router, and the data forwarding rate of the router, determine the queuing delay for the messages to be forwarded after arriving at the router. Specifically, the following formula is used to calculate the queuing delay for the messages to be forwarded after arriving at router i:

[0092]

[0093] Among them, τ q(i) is the queuing delay after a message arrives at router i and is forwarded. This queuing delay occurs because an uncertain number of messages are waiting to be forwarded ahead of the message after it arrives at router i. It is uncertain, and the main influencing factors include router utilization, message arrival speed, and router transmission speed. q (E q (i) represents the total length of the queued packets at router i, E q (i) represents the packet queuing model at the router, β r (i) represents the load rate of router i, v r (i) represents the data forwarding rate of router i.

[0094] S6: Based on the transmission delay of each data packet and the queuing delay for forwarding the packets after they arrive at each router, the random delay is obtained:

[0095]

[0096] Where, τ S For random delay, K is the number of data packets, τ t (l) represents the transmission delay of data packet l, R represents the number of routers, and τ q (i) is the queuing delay for forwarding a message after it arrives at router i.

[0097] S7: Based on the deterministic delay and the random delay, determine the wireless communication delay of the smart substation: τ = τ C +τ S Where τ is the wireless communication delay of the smart substation.

[0098] Specifically, by substituting the queued message length into the queuing delay calculation formula and combining it with deterministic delay and transmission delay, the probability distribution characteristics of communication delay can be obtained. The probability distribution characteristics of communication delay represent the probability of different communication delays τ occurring; that is, the horizontal axis is τ, and the vertical axis is probability. For example... Figure 2 The final plot shows the random distribution characteristic curve of communication delay.

[0099] To verify the effectiveness of this invention, the wireless communication process of a smart substation is simulated using OPNET simulation software. The simulation process reveals the impact of factors such as information flow parameters, path loss, and environmental noise on wireless communication latency during actual operation of a wireless smart substation.

[0100] (1) Based on the characteristics of intelligent equipment in intelligent substations and the required node information, construct the corresponding wireless node model in OPNET simulation software.

[0101] For the selection of node models, the central switch and the switches within each bay use the Wlan2_router_adv node model provided by the OPNET simulation software. The wireless node model for the merging unit and intelligent terminals is Wlan_station_adv. The node model for protection and measurement devices is Wlan_wkstn_adv. Based on the models provided by OPNET, appropriate modifications are made to obtain intelligent device models that conform to the requirements of a wireless intelligent substation.

[0102] like Figure 3 As shown, the IEC61850 standard does not define the IEEE802.11 protocol. This invention constructs an IEC61850 data frame format based on the IEEE802.11 protocol using OPNET simulation software.

[0103] (2) Based on the network structure of the intelligent substation, build a network topology in OPNET that conforms to the wireless communication of the intelligent substation, such as... Figure 4 As shown, the D2-1 type intelligent substation equipment structure is adopted, consisting of two transformer bays, six feeder bays, and one bus bay. Each bay has a switch to enable communication between the devices within that bay, and each bay's switch is interconnected with the central switch. Figure 5 The diagram shows the node model of the smart devices within the interval.

[0104] (3) Based on the different characteristics of each information flow, a corresponding business model is constructed through the business configuration module. Specifically, the periodic, random, and bursty messages in the smart substation are configured mainly through the Application Config module and the Profile Config module in the OPNET simulation software:

[0105] The data length of the periodic message is configured to be 256 bytes, and the frequency of sending the data stream is 50Hz. The simulation is performed using the video conferencing service built into OPNET.

[0106] The random message data length is configured to 128 bytes, and the arriving data packets follow an exponential distribution with λ = 0.01. Similarly, the video conferencing service built into OPNET is used for simulation.

[0107] The burst message data length is configured to 1024 bytes. Arriving packets follow a Pareto distribution, where the ON state time parameter is k = 0.512 ms and α = 1.1, and the OFF state follows a Pareto distribution. The negative exponential distribution, where λ = 200, is simulated using the FTP service built into OPNET.

[0108] After configuring various message types, the data stream is transmitted between the process layer network and the station control layer network:

[0109] During normal operation, switch status information and analog data are periodically transmitted from the bay-level intelligent electronic equipment to the station control-level monitoring equipment.

[0110] In the event of a fault or multiple faults, protection actions and switch positions are sent directly from the intelligent electronic equipment at the process level to the station control level.

[0111] (4) Run the simulation scenario configured above to obtain the simulation delay results.

[0112] The simulation runtime was set to 40 minutes, and delay analysis was performed on the GOOSE trip message and its arrival delay data, such as... Figure 6 He Ru Figure 7 As shown, the distribution of wireless latency roughly conforms to a normal distribution, with latency remaining between 1.6ms and 1.65ms, which meets the requirements of the IEC 61850 standard for communication latency.

[0113] This invention analyzes the communication delay of messages in a wireless intelligent substation, dividing the delay into deterministic and random delays. The random delay is quantified and estimated based on the probability distribution characteristics of messages in the intelligent substation, thus obtaining information on each segment of uncertain delay. Then, an OPNET simulation model of wireless communication in the intelligent substation is established, simulating the actual message transmission method and the cumulative probability distribution of the data stream. The simulation results of the wireless communication delay are analyzed, demonstrating the effectiveness of the wireless communication delay determination method of this invention and providing important reference for wireless communication in intelligent substations.

[0114] Example 2

[0115] In order to implement the method corresponding to Embodiment 1 above and achieve the corresponding functions and technical effects, a smart substation wireless communication delay determination system is provided below.

[0116] like Figure 8 As shown, the intelligent substation wireless communication delay determination system provided in this embodiment includes: a data acquisition unit 1, a deterministic delay determination unit 2, a transmission delay determination unit 3, a queuing message determination unit 4, a queuing delay determination unit 5, a random delay determination unit 6, and a communication delay determination unit 7.

[0117] The data acquisition unit 1 is used to acquire the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, the packet propagation delay of each wireless channel, the number of data packets, the data frame length corresponding to each data packet, the channel bandwidth, the load rate of each router, and the data forwarding rate of each router.

[0118] In the communication process of a smart substation, messages are forwarded by multiple routers, processed and parsed by multiple smart electronic devices, and transmitted through multiple wireless channels. Each wireless channel includes a receiver and a transmitter. Messages are encapsulated into data packets during communication, and data packets are encapsulated into data frames during communication.

[0119] The deterministic delay determination unit 2 is connected to the data acquisition unit 1. The deterministic delay determination unit 2 is used to obtain the deterministic delay based on the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, and the packet propagation delay of each wireless channel.

[0120] The transmission delay determination unit 3 is connected to the data acquisition unit 1. The transmission delay determination unit 3 is used to determine the transmission delay of any data packet based on the data frame length corresponding to the data packet and the channel bandwidth.

[0121] The queuing message determination unit 4 is connected to the data acquisition unit 1. The queuing message determination unit 4 is used to determine the total length of queued messages at each router using the Monte Carlo method, based on the message queuing model at each router. The message queuing model at each router is pre-determined according to the type of messages forwarded by each router.

[0122] The queuing delay determination unit 5 is connected to the queuing packet determination unit 4. The queuing delay determination unit 5 is used to determine the queuing delay for forwarding a packet after it arrives at the router, based on the total length of the queuing packets at the router, the load rate of the router, and the data forwarding rate of the router, for any router.

[0123] The randomness delay determination unit 6 is connected to the transmission delay determination unit 3 and the queuing delay determination unit 5 respectively. The randomness delay determination unit 6 is used to obtain the randomness delay based on the transmission delay of each data packet and the queuing delay after the message arrives at each router for forwarding.

[0124] The communication delay determination unit 7 is connected to the deterministic delay determination unit 2 and the random delay determination unit 6 respectively. The communication delay determination unit 7 is used to determine the wireless communication delay of the smart substation based on the deterministic delay and the random delay.

[0125] Compared with the prior art, the intelligent substation wireless communication delay determination system provided in this embodiment has the same beneficial effects as the intelligent substation wireless communication delay determination method provided in Embodiment 1, and will not be repeated here.

[0126] Example 3

[0127] This embodiment provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor runs the computer program to enable the electronic device to execute the wireless communication delay determination method for smart substations according to Embodiment 1.

[0128] Alternatively, the aforementioned electronic device may be a server.

[0129] In addition, this embodiment of the invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for determining the wireless communication delay of a smart substation according to Embodiment 1.

[0130] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0131] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for determining the wireless communication delay in a smart substation, characterized in that, The method for determining the wireless communication delay of the intelligent substation includes: The system acquires the packet forwarding latency of each router, the packet processing and parsing latency of each intelligent electronic device, the packet propagation latency of each wireless channel, the number of data packets, the data frame length corresponding to each data packet, the channel bandwidth, the load rate of each router, and the data forwarding rate of each router. During communication in the intelligent substation, packets are forwarded by multiple routers, processed and parsed by multiple intelligent electronic devices, and transmitted through multiple wireless channels. Each wireless channel includes a receiver and a transmitter. Packets are encapsulated into data packets during communication, and data packets are encapsulated into data frames during communication. The deterministic delay is obtained based on the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, and the packet propagation delay of each wireless channel. For any data packet, the transmission delay of the data packet is determined based on the data frame length corresponding to the data packet and the channel bandwidth; Based on the packet queuing model at each router, the Monte Carlo method is used to determine the total length of the queued packets at each router; the packet queuing model at each router is determined in advance according to the type of packets forwarded by each router. For any given router, the queuing delay for forwarding a packet after it arrives at the router is determined based on the total length of the queued packets at the router, the router's load rate, and the router's data forwarding rate. Random delay is obtained by considering the transmission delay of each data packet and the queuing delay for forwarding the message after it arrives at each router. The wireless communication delay of the smart substation is determined based on the deterministic delay and the random delay.

2. The method for determining the wireless communication delay of an intelligent substation according to claim 1, characterized in that, The deterministic delay is calculated using the following formula: t C =∑ i∈R t r (i)+∑ j∈D t m (j)+∑ k∈L t w (k); Where, τ C For deterministic delay, R is the number of routers, τ r (i) represents the packet forwarding delay of router i, D represents the number of smart electronic devices, and τ m (j) represents the message processing and parsing delay of intelligent electronic device j, L represents the number of wireless channels, and τ w (k) represents the message propagation delay of wireless channel k.

3. The method for determining the wireless communication delay of an intelligent substation according to claim 1, characterized in that, The transmission delay of data packet l is calculated using the following formula: Where, τ t (l) represents the transmission delay of data packet l, L M Let L be the length of the data frame corresponding to data packet l, and B be the channel bandwidth.

4. The method for determining the wireless communication delay of an intelligent substation according to claim 1, characterized in that, Based on the packet queuing model at each router, the Monte Carlo method is used to determine the total length of queued packets at each router, specifically including: For any given router, determine the queuing probability of packets at that router based on the packet queuing model at that router; Based on the queuing probability of packets at the router, the probability distribution of the total length of queued packets at the router is determined using the Monte Carlo method. The total length of the queued packets at the router is determined based on the probability distribution of the total length of the queued packets.

5. The method for determining the wireless communication delay of an intelligent substation according to claim 4, characterized in that, The packet queuing model at each router is an M / M / 1 queuing model.

6. The method for determining the wireless communication delay of an intelligent substation according to claim 1, characterized in that, The queuing delay for forwarding a packet after it arrives at router i is calculated using the following formula: Where, τ q (i) is the queuing delay for forwarding a message after it arrives at router i, L q (E q (i) represents the total length of the queued packets at router i, E q (i) represents the packet queuing model at the router, β r (i) represents the load rate of router i, v r (i) represents the data forwarding rate of router i.

7. The method for determining the wireless communication delay of an intelligent substation according to claim 1, characterized in that, The randomness delay is calculated using the following formula: t S =∑ l∈K t t (l)+∑ i∈R t q (i); Where, τ S For random delay, K is the number of data packets, τ t (l) represents the transmission delay of data packet l, R represents the number of routers, and τ q (i) is the queuing delay for forwarding a message after it arrives at router i.

8. A smart substation wireless communication delay determination system, characterized in that, The intelligent substation wireless communication delay determination system includes: The data acquisition unit is used to acquire the packet forwarding delay of each router, the packet processing and parsing delay of each intelligent electronic device, the packet propagation delay of each wireless channel, the number of data packets, the data frame length corresponding to each data packet, the channel bandwidth, the load rate of each router, and the data forwarding rate of each router. In the communication process of the intelligent substation, the packets are forwarded by multiple routers, processed and parsed by multiple intelligent electronic devices, and transmitted through multiple wireless channels. Each wireless channel includes a receiver and a transmitter. The packets are encapsulated into data packets during the communication process, and the data packets are encapsulated into data frames during the communication process. A deterministic delay determination unit, connected to the data acquisition unit, is used to obtain the deterministic delay based on the packet forwarding delay of each router, the packet processing and parsing delay of each smart electronic device, and the packet propagation delay of each wireless channel. A transmission delay determination unit, connected to the data acquisition unit, is used to determine the transmission delay of any data packet based on the data frame length corresponding to the data packet and the channel bandwidth. The queuing message determination unit, connected to the data acquisition unit, is used to determine the total length of the queued messages at each router using the Monte Carlo method based on the message queuing model at each router; the message queuing model at each router is determined in advance according to the type of messages forwarded by each router. The queuing delay determination unit, connected to the queuing packet determination unit, is used to determine the queuing delay for forwarding a packet after it arrives at the router, based on the total length of the queued packets at the router, the load rate of the router, and the data forwarding rate of the router, for any given router. The randomness delay determination unit is connected to the transmission delay determination unit and the queuing delay determination unit respectively, and is used to obtain the randomness delay based on the transmission delay of each data packet and the queuing delay after the message arrives at each router for forwarding. A communication delay determination unit is connected to both the deterministic delay determination unit and the random delay determination unit, and is used to determine the wireless communication delay of the smart substation based on the deterministic delay and the random delay.

9. An electronic device, characterized in that, The device includes a memory and a processor, wherein the memory stores a computer program and the processor runs the computer program to enable the electronic device to perform the intelligent substation wireless communication delay determination method according to any one of claims 1 to 7.

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