Service access method for distribution network equipment

Abstract

The present invention discloses a service access method for distribution network equipment, the method comprising: dividing services accessing the distribution communication network into different priorities, including high priority services and low priority services; the distribution network accesses the accessed services according to the set access rules. The present invention introduces a priority queue control mechanism to access different types of services, and proposes a link switching and data caching scheme to provide a reliable communication channel for remote control and intelligent metering services.

Description

Technical Field

[0001] The present invention belongs to the technical field of power distribution Internet of Things, and in particular relates to a service access method for power distribution network equipment. Background Art

[0002] The power distribution Internet of Things is the embodiment of the application of the ubiquitous power Internet of Things. It is a new form of distribution network that deeply integrates the Internet of Things and the distribution network. It provides new technical means for the precise planning, efficient operation, lean operation and maintenance, and high-quality service of medium and low voltage distribution networks. With the expansion and development of the intelligent power distribution Internet of Things, its application environment is becoming increasingly complex. Among them, communication terminal equipment is widely distributed, measurement and monitoring points are increasing, and business carrying requirements show differentiated characteristics. This puts higher requirements on the reliability and security of information transmission in the distribution network. The power distribution Internet of Things constructs a system architecture consisting of four parts: cloud, pipe, edge, and end. Figure 2 As shown, by giving distribution network equipment sensitive and accurate perception capabilities and the functions of interconnection, intercommunication and interoperability between devices, intelligent applications such as panoramic monitoring of distribution network status, lean operation and maintenance of equipment, and dynamic topology identification of equipment can be realized.

[0003] Currently, most IoT systems use centralized computing management in cloud computing centers. For the power distribution IoT with massive data and terminals, this will cause a large amount of energy and bandwidth consumption in the system, and is not conducive to reducing latency.

[0004] Traditional networks usually provide deterministic interconnection services for devices by providing dedicated line access. However, the massive device access requirements and cost constraints of the power distribution Internet of Things make traditional methods no longer applicable. Although technologies such as time-sensitive networks and time-triggered networks provide ideas for the deterministic interconnection of devices, these technologies cannot be directly applied to the realization of deterministic interconnection of the power distribution Internet of Things due to their complex implementation methods and inability to be applied to large-scale networks. In addition, the suddenness of services in the power distribution Internet of Things will also seriously affect the deterministic service performance of the services. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a service access method for distribution network equipment, so as to realize real-time monitoring and service quality assurance of various services of smart grid.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A service access method for distribution network equipment, the method comprising:

[0008] Classify the services connected to the power distribution communication network into different priorities, including high-priority services and low-priority services;

[0009] The distribution network accesses the accessed services according to the set access rules;

[0010] The access rules include:

[0011] When a high-priority service arrives, if there is no waiting connection in the high-priority queue, or the number of waiting connections in the low-priority queue is greater than the threshold, the existing connection in the low-priority queue is accessed. Otherwise, the distribution network accesses the connection from the high-priority queue.

[0012] When a low-priority service arrives, if there are waiting connections in the high-priority queue and the number of waiting connections in the low-priority queue does not exceed the threshold, the distribution network accesses the connection with the high-priority queue; otherwise, the distribution network accesses the connection with the low-priority queue.

[0013] Furthermore, the service includes a remote control service, and the distribution network equipment transmits data in the form of a main channel combined with a backup channel when providing the remote control service.

[0014] Furthermore, the data transmission in the form of a main channel combined with a backup channel specifically includes:

[0015] A single power distribution communication terminal of the power distribution network equipment uses USIM cards from different public wireless operators, and determines a primary card and a standby card according to average signal and interference strengths of different USIM cards.

[0016] Furthermore, the data of the power distribution network equipment is transmitted to the wireless router through the main channel, and the data is arranged on the wireless router and forwarded to the corresponding business system;

[0017] When a communication failure occurs in the primary channel, the ongoing data transmission is switched to the backup channel.

[0018] Furthermore, for the downlink connection, the wireless router first detects the availability of the primary channel. If the primary channel is available, the data is transmitted on the primary channel, otherwise the data is transmitted on the backup channel.

[0019] Furthermore, after the main channel returns to normal, data transmission is switched from the backup channel to the main channel.

[0020] Furthermore, the service includes a metering service of a smart meter. The smart meter includes a wireless communication module and a data cache module. The smart meter transmits data using a single link. The data transmitted by the smart meter can be retransmitted.

[0021] Furthermore, the data uploaded by the smart meter is divided into data of different priorities, including emergency data and non-emergency data, and whether the channel of the smart meter is blocked when transmitting data is monitored in real time. The channel blocking is judged based on whether the data transmission volume per unit time is greater than a threshold value;

[0022] When the channel is blocked, non-urgent data is cached locally and only urgent data is uploaded. When the channel is no longer blocked, uploading of non-urgent data is resumed.

[0023] Furthermore, the smart meter adopts a multi-hop communication mode, and when the channel is blocked, the smart meter forwards the data to the gateway through other connected smart meters.

[0024] Furthermore, the local data stored in the smart meter is accessible to authorized users.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention introduces a priority queue control mechanism to access different types of service distribution terminals according to their own communication needs and network status, select appropriate access networks to ensure the QoS of the service, reduce the possibility of service transmission abnormalities, balance the network load, and improve the resource utilization of heterogeneous network systems.

[0027] (2) The present invention proposes a mechanism for maintaining continuous connection of remote control services with seamless link switching, thereby providing a reliable communication channel for remote control services.

[0028] (3) The present invention proposes a data caching solution to reduce content acquisition time, reduce network duplication traffic, avoid dual-link transmission methods, and reduce costs. A multi-hop communication method is adopted, and smart meters are used as routers to achieve load diversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the service access method flow of the distribution network equipment provided by an embodiment of the present invention;

[0030] Figure 2 It is the system architecture of the power distribution Internet of Things;

[0031] Figure 3 It is a schematic diagram of a process based on a priority queue mechanism according to an embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of a flow chart based on a link switching mechanism according to an embodiment of the present invention;

[0033] Figure 5 It is a flow chart of the data caching mechanism according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0035] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0036] Currently, most IoT systems use centralized computing management in cloud computing centers. For the power distribution IoT with massive data and terminals, this will cause a large amount of energy and bandwidth consumption in the system, and is not conducive to reducing latency.

[0037] Traditional networks usually provide deterministic interconnection services for devices by providing dedicated line access. However, the massive device access requirements and cost constraints of the power distribution Internet of Things make traditional methods no longer applicable. Although technologies such as time-sensitive networks and time-triggered networks provide ideas for the deterministic interconnection of devices, these technologies cannot be directly applied to the realization of deterministic interconnection of the power distribution Internet of Things due to their complex implementation methods and inability to be applied to large-scale networks. In addition, the suddenness of services in the power distribution Internet of Things will also seriously affect the deterministic service performance of the services.

[0038] In order to solve the above technical problems, the following embodiments of the service access method of the distribution network equipment of the present invention are proposed.

[0039] Example 1

[0040] Reference Figure 1 ,like Figure 1 FIG. 1 is a flow chart of a method for accessing a service of a distribution network device provided in this embodiment. The method specifically includes:

[0041] The services accessing the power distribution communication network are divided into different priorities, including high priority services and low priority services.

[0042] The distribution network accesses the connected services according to the set access rules.

[0043] Specifically, the access rules in this embodiment include:

[0044] When a high-priority service arrives, if there is no waiting connection in the high-priority queue, or the number of waiting connections in the low-priority queue is greater than the threshold, the existing connection in the low-priority queue is accessed. Otherwise, the distribution network accesses the connection from the high-priority queue.

[0045] When a low-priority service arrives, if there are waiting connections in the high-priority queue and the number of waiting connections in the low-priority queue does not exceed the threshold, the distribution network accesses the connection with the high-priority queue; otherwise, the distribution network accesses the connection with the low-priority queue.

[0046] The key difference between various services accessing the distribution communication network lies in the priority of the services, which depends on the importance and urgency of the services. On the one hand, services such as protection and remote control require communication channels to accurately and instantly transmit relevant control signaling data between DTUs (data line transmission equipment) and the distribution system; once data transmission fails, it will cause equipment operation failure, and then cause grid failure. On the other hand, services such as smart meters and online monitoring require accurate data transmission while allowing a retransmission mechanism when link communication fails. To this end, a priority queue model is introduced to control the access of multiple services to the distribution communication network. Multiple services are divided into high-priority services and low-priority services, and each service generates a service queue. Reference Figure 3 ,like Figure 3 The figure is a schematic diagram of the process flow based on the priority queue mechanism of this embodiment.

[0047] These two types of services occupy different queues to schedule access to the network. The high priority category mainly includes services such as protection and remote control, while the low priority category includes services such as metering and sensing. It is assumed that the arrival process of the two types of services follows a Poisson distribution with mean values ​​of λ1 and λ2 respectively. The connection duration follows a negative exponential distribution with parameters μ1 and μ2 respectively. The high priority queue and the low priority queue are called L1 and L2 respectively.

[0048] Then the multi-service access mechanism controlled by priority queue can be described as:

[0049] 1) When a high-priority service arrives: If there are no waiting connections in L1, or the number of waiting connections in L2 exceeds N, the network will access the existing connections in L2. Otherwise, the network will access the connection in L1.

[0050] 2) When low-priority service arrives: If L1 has a waiting connection and the number of L2 waiting connections does not exceed N, the network will access the L1 connection.

[0051] Let L1(t)=i and L2(t)=j be the number of connections that L1 and L2 are waiting for at time t. Let I1(t)=h and I2(t)=l be the number of connections that have been admitted in L1 and L2 at time t. Then the probability state of the network at time t is:

[0052] X(t)={I1(t),I2(t),L1(t),L2(t);t≥0}

[0053] Its probability state space is:

[0054] Ω={(i,j,h,l);0≤i+j≤m,i,j,h,l≥0}

[0055] Considering that the arrival process and connection duration follow Poisson distribution and negative exponential distribution respectively, the probability state of the network {X(t), t≥0} is a four-dimensional Markov process, which has a stationary distribution:

[0056]

[0057] where (i,j,h,l)∈Ω.

[0058] Therefore, by introducing N as a control priority parameter of the high priority queue relative to the low priority queue, the network can access different services according to different priorities.

[0059] Example 2

[0060] For remote control services in power distribution, most DTUs are deployed with wireless communication terminals of public operators. Due to the harsh working environment such as high temperature and humidity, as well as the interference and tidal effects of public wireless networks, communication channels are often faced with the challenge of providing continuous connections, especially when transmitting important data or necessary commands.

[0061] In view of the above shortcomings, this embodiment proposes a mechanism for maintaining continuous connection of a remote control service based on seamless link switching.

[0062] Specifically, refer to Figure 4 ,like Figure 4 The figure is a flow chart of the link switching mechanism of this embodiment. Dual USIM cards from different public wireless operators are used in a single power distribution communication terminal. According to the average signal and interference strength of the USIM cards, one of the USIM cards is used as the primary card and the other as the backup card. A single remote control service will have a primary channel and a backup channel.

[0063] from Figure 4 It can be seen that the DTU is connected to the dual-mode wireless module through the RS 232 / 485 or Ethernet interface. Then the data of the DTU is transmitted to the wireless router through the main link, and the data is arranged on the router and forwarded to the corresponding business system.

[0064] When a communication failure occurs in the main link due to tidal effects or USIM failure, the dual-mode wireless module will switch the ongoing data transmission to the backup link so that the business data will not be interrupted due to the communication failure.

[0065] For downlink connection, i.e. data transmission from the service station to the terminal, the wireless router first detects the availability of the primary link. If available, the data will be transmitted on the primary link. Otherwise, the backup link will be used.

[0066] It should be noted that when the primary link is restored and operating normally, data transmission will return from the backup link to the primary link. This is because the primary link is determined based on its good performance with respect to average signal and interference strength.

[0067] Example 3

[0068] For the smart meter measurement service in power distribution, this embodiment realizes continuous data collection of the smart meter on the wireless communication channel through data caching. Figure 5 ,like Figure 5 FIG. 4 is a flow chart of the data caching mechanism of this embodiment.

[0069] Different from the remote control service which requires real-time seamless switching of data transmission, the data of smart meters emphasizes the accuracy and integrity of transmitted data and allows retransmission, thereby avoiding the dual-link method and reducing costs. This embodiment introduces a data cache mechanism, adding a large-capacity data cache module to the smart meter. Since all data does not need to be uploaded to the master station system, data can be sorted according to priority, and non-urgent data can be cached locally.

[0070] On the one hand, locally cached data can be used for information regulation during local control, and on the other hand, a large number of transmission channels are released.

[0071] It should be noted that in this embodiment, authorized users are allowed to obtain content from any location on the network to reduce content acquisition time and reduce network duplication traffic.

[0072] In this embodiment, the online monitoring system for the metering device constructs different monitoring tasks according to different metering operation and maintenance business requirements, and sets reasonable interface parameters.

[0073] This embodiment develops a data caching mechanism in the wireless communication module of the smart meter to implement the function of a gateway, that is, the module receives data to be transmitted, processes the data cache when the communication link is unavailable, and forwards the data when the communication is restored.

[0074] Since smart meters close to the gateway will forward more data than smart meters far from the gateway, their data caches have longer queues and are prone to congestion, which will become a bottleneck affecting network throughput and latency. In order to solve this problem, the smart meter in this embodiment adopts a multi-hop communication method. When the channel is blocked, the smart meter forwards the data to the gateway through other connected smart meters. Smart meters can upload data directly to the gateway, and can also forward data to the gateway through other smart meters, using smart meters as routers to achieve load diversion.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A service access method for distribution network equipment, characterized in that: The method comprises: Classify the services connected to the power distribution communication network into different priorities, including high-priority services and low-priority services; Establish a pre-defined access mechanism, including: Determine the status of the distribution network: Let L1(t)=i and L2(t)=j be the number of connections L1 and L2 are waiting for at time t, and let I1(t)=h and I2(t)=l be the number of connections already admitted in L1 and L2 at time t; The probability state of the distribution network at time t is: X(t)={I1(t),I2(t),L1(t),L2(t);t≥0} The probability state space of the distribution network is: Ω={(i,j,h,l);0≤i+j≤m,i,j,h,l≥0}; The service arrival process and connection duration obey Poisson distribution and negative exponential distribution respectively. The probability state of the network {X(t), t≥0} is a four-dimensional Markov process with a stationary distribution: where (i, j, h, l)∈Ω; A priority control parameter N is introduced to control the access priority of the distribution network, and the priority control parameter N is pre-set according to different application scenarios; When a high-priority service arrives, if there is no waiting connection in L1, or the number of waiting connections in L2 exceeds N, the network will access the existing connection in L2. Otherwise, the distribution network accesses the connection in the high-priority queue; When a low-priority service arrives, if L1 has a waiting connection and the number of L2 waiting connections does not exceed N, the network will access the L1 connection; Among them, L1 represents a high priority queue, L2 represents a low priority queue, and N is a control priority parameter of the high priority queue relative to the low priority queue.

2. The service access method for distribution network equipment according to claim 1, characterized in that: The service includes a remote control service. When the distribution network equipment provides the remote control service, data is transmitted in the form of a main channel combined with a backup channel.

3. The service access method for distribution network equipment according to claim 2, characterized in that: The data transmission in the form of a main channel combined with a standby channel specifically includes: A single power distribution communication terminal of the power distribution network equipment uses USIM cards from different public wireless operators, and determines a primary card and a standby card according to average signal and interference strengths of different USIM cards.

4. The service access method for distribution network equipment according to claim 3, characterized in that: The data of the distribution network equipment is transmitted to the wireless router through the main channel, and the data is arranged on the wireless router and forwarded to the corresponding business system; When a communication failure occurs in the primary channel, the ongoing data transmission is switched to the backup channel.

5. The service access method for distribution network equipment according to claim 4, characterized in that: For downlink connections, the wireless router first detects the availability of the primary channel. If the primary channel is available, the data is transmitted on the primary channel, otherwise the data is transmitted on the backup channel.

6. The service access method for distribution network equipment according to claim 4, characterized in that: After the main channel returns to normal, data transmission is switched from the backup channel to the main channel.

7. The service access method for distribution network equipment according to claim 1, characterized in that: The service includes a metering service of a smart meter. The smart meter includes a wireless communication module and a data cache module. The smart meter transmits data using a single link. The data transmitted by the smart meter can be retransmitted.

8. The service access method for distribution network equipment according to claim 7, characterized in that: The data uploaded by the smart meter is divided into data of different priorities, including emergency data and non-emergency data, and real-time monitoring is performed to determine whether the channel of the smart meter is blocked when transmitting data. Channel blockage is determined based on whether the data transmission volume per unit time is greater than a threshold value; When the channel is blocked, non-urgent data is cached locally and only urgent data is uploaded. When the channel is no longer blocked, uploading of non-urgent data is resumed.

9. The service access method for distribution network equipment according to claim 8, characterized in that: The smart meter adopts a multi-hop communication mode. When the channel is blocked, the smart meter forwards the data to the gateway through other connected smart meters.

10. The service access method for distribution network equipment according to claim 8, characterized in that: The local data stored in the smart meter is accessible to authorized users.

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