CN103532231B - Intelligent power distribution network IEEE1588 timing synchronization system on basis of industrial Ethernet direct connection access rings - Google Patents

Abstract

The invention relates to a time synchronization system for a distribution network, in particular to an IEEE1588 time synchronization system for an intelligent distribution network based on industrial Ethernet direct connection into the ring. Including the backbone layer and the access layer, the main station gateway switch of the backbone layer is connected to the upper-level network transmission precision clock device, the main station gateway switch and the sub-station switches are connected to form a ring structure, and the first gateway switch and the second gateway switch of the access layer are connected in the sub-station The two sides of the station switch are then connected to the access layer switch to form a ring structure. The main station gateway switch, the first gateway switch and the second gateway switch are set as boundary clocks, and the slave station switches and access layer switches are set as transparent clocks. The electrical terminal device is set to an ordinary clock. The invention has the advantages of simple technology, high time precision, low dependence on GPS, cost saving, good expansion, wide coverage area, good adaptability to the direct connection into the ring of the access layer, and can meet the time synchronization requirements of the intelligent distribution network.

Description

IEEE1588 timing synchronization system for intelligent distribution network based on industrial Ethernet direct connection into the ring

technical field

The invention relates to a timing synchronization system for a distribution network, in particular to an IEEE1588 timing synchronization system for an intelligent distribution network based on industrial Ethernet direct connection into the ring.

Background technique

At present, the time synchronization accuracy of each backbone node of the transmission network has reached a high standard, and the time synchronization accuracy of the medium-voltage nodes covered by distribution network automation is still relatively low. In the construction of smart distribution network, the wide-area measurement and control system of smart distribution network with synchrophasor acquisition function is the key supporting technology of smart distribution network. Technologies such as network wide-area protection and event management, and smart distribution network seamless self-healing must make the timing accuracy of the distribution network reach the microsecond level, so the research on the construction of an accurate time synchronization system for the smart distribution network has important practical significance.

The current time synchronization research in power systems is mainly based on substation automation. The main technologies used are: GPS time synchronization, second pulse time synchronization, IRIG-B code, Simple Network Time Protocol SNTP, Precision Time Synchronization Protocol PTP, etc. Among them, GPS synchronization has high precision, but it is expensive and not suitable for application in a large number of nodes in the distribution network, and its stability and security are not very reliable; second pulse and IRIG-B code synchronization can also achieve high precision, but additional control is required. Time-dedicated lines cannot be used in distributed systems with relatively large span distances such as distribution networks; SNTP network message synchronization and time synchronization accuracy can only reach the ms level. IEEE1588 is also called the precise time synchronization protocol PTP of the distributed control and measurement system. It synchronizes the network to achieve sub-microsecond time accuracy through the timing packet in the Ethernet and stamps the bottom layer. This protocol can multiplex the Ethernet The communication network occupies less resources and does not need to lay additional lines, which can reduce the cost of system construction. At present, the application research of IEEE1588 in power system is mostly concentrated in the field of substation automation, and the application in distribution network is in its infancy. And there are a large number of domestic and foreign manufacturers mature switch products that support the IEEE1588 protocol.

Optical fiber communication has become the preferred technology for distribution network communication system due to its large capacity bandwidth, strong anti-interference ability, relatively low cost, low bit error rate, high speed, good confidentiality and other reliable and stable communication quality. With the massive increase of IP services, fiber optic Ethernet technology has gradually become the preferred technology in the backbone layer and access layer of the distribution network communication system. The scheme of building distribution automation backbone network with Gigabit Ethernet ring network and building distribution automation access network with 100M industrial Ethernet ring network has become a typical solution for the construction of distribution network automation communication system. Based on this typical scheme, the present invention studies a timing system that adopts IEEE1588 multiplexing based on optical fiber Ethernet technology distribution network communication system.

Contents of the invention

According to the deficiencies in the prior art above, the problem to be solved by the present invention is: to provide a simple technology, high time accuracy, less dependence on GPS, cost saving and good expansion, wide coverage area, especially suitable for access layer It is an IEEE1588 timing synchronization system and method for an intelligent distribution network based on an industrial Ethernet direct connection into a ring with a direct connection into a ring structure and capable of meeting the time synchronization requirements of an intelligent distribution network.

The technical solution adopted by the present invention to solve its technical problems is:

The intelligent power distribution network IEEE1588 timing synchronization system based on industrial Ethernet direct connection into the ring includes a backbone layer and an access layer. The backbone layer includes a master station gateway switch and multiple substation switches, and the master station gateway switch is connected to the upper Network transmission precision clock device, main station gateway switch and substation switch are connected through Gigabit optical fiber interface to form a ring structure, the access layer includes the first gateway switch, the second gateway switch and multiple access layer switches, the first gateway switch and the second gateway switch The two gateway switches are respectively connected to both sides of the sub-station switch through the 100M optical fiber interface and then connected to the access layer switch to form a ring structure. The main station gateway switch, the sub-station switch, the first gateway switch, the second gateway switch and the Layer switches are connected to power distribution terminal devices, the main station gateway switch, first gateway switch and second gateway switch are set as boundary clocks, substation switches and access layer switches are set as transparent clocks, and power distribution terminal devices are set as ordinary clocks;

The steps of the IEEE1588 time synchronization method for intelligent distribution network based on industrial Ethernet direct connection into the ring are as follows:

1) The master station gateway switch at the backbone layer receives the clock source message from the upper-level network transmission precision clock device. By setting the master station gateway switch as a boundary clock, the master station gateway switch terminates the message after receiving the upper-level time message , and then the gateway switch of the master station updates the local clock according to the received information;

2) The main station gateway switch uses the updated local clock as the main clock, and sends the message information to other sub-station switches connected to the backbone layer and the power distribution terminal device connected to the main station gateway switch through the main clock port , the substation switches are all set as transparent clocks, update their own clocks after receiving the message information, and at the same time send the message information to the power distribution terminal device connected to the substation switch;

3) While the gateway switch of the master station transmits the message information to the switch of the substation, the timing clock of the gateway switch of the master station passes through the switch of the substation and sends it to the first gateway switch in the access layer. Between the two connected access layer switches, the timing clock of the gateway switch of the master station is sent to the first gateway switch and the second gateway switch at the same time, and both the first gateway switch and the second gateway switch are set as boundary clocks. The first gateway switch and the second gateway switch update the local clocks after receiving the message information, and send the updated local clocks as the master clock to the access layer switch connected to it and the first gateway switch and the second gateway switch. The power distribution terminal device connected to the switch at the access layer performs time calibration; if a ring is blocked between the second gateway switch and the sub-station switch, the timing clock of the master station gateway switch is transmitted to the access switch through the sub-station switch. The first gateway switch of the entry layer, after the first gateway switch completes the time synchronization, it acts as the master clock, and sends the message information to other access layer switches connected to it, the second gateway switch, and the access layer switch and the first gateway switch. The power distribution terminal device connected to the switch and the second gateway switch, and the access layer switch are all set as transparent clocks.

Under the unified timing of the precise clock source, the communication ring network at the backbone layer covers the distribution network master station (city dispatching center) and the distribution network substations (each substation), and the access layer ring network is composed of two gateway switches at this layer, namely the first The gateway switch and the second gateway switch are directly connected to the sub-station switches of the backbone layer network of the local communication convergence point from both sides. The access ring covers the switching stations, ring network cabinets, power distribution stations, and pole-mounted switches of the communication convergence point, and finally forms a structure in which the large ring of the backbone layer and multiple small rings of the access layer are directly connected by the IEEE1588 protocol The mechanism of layer-by-layer transfer in the middle. In the large ring of the backbone layer, select the switch node located at the main station to define as the gateway switch of this layer, that is, the gateway switch of the main station, select the clock type as boundary clock BC, and select other nodes as sub-station switches, and select the clock type as transparent clock TC (P2P mode). In the small ring of the access layer, select the first gateway switch and the second gateway switch (each directly connected into the ring has two gateway switches), the clock type is selected as boundary clock BC, and the clock type of other access layer switch nodes is selected It is a transparent clock TC (P2P mode). The boundary clock BC node is the boundary that divides the PTP time calibration sub-domain. It can form a PTP sub-domain with a clear structure, multiple layers, relatively independent, and a simple time synchronization process. The upper layer is the lower layer. Finally, a clock calibration tree system is formed. The Sync message sending period of each PTP sub-domain is generally 2 seconds, and the local clock error will gradually accumulate in these two seconds until the next update. The next layer will add the error accumulated in the local 2 seconds to the error accumulated in the previous layer for 2 seconds. The more layers there are, the more errors will accumulate. The gateway switch is equivalent to the gateway of a clock information flow. The gateway switch is guarded at the connection between the ring network and the upper and lower networks. It is set as the boundary clock BC, so that this layer is separated from its upper and lower layer timing systems, forming Relatively independent PTP sub-domains, the communication network at each level acts as a large timing whole, and the boundary clock BC of the gateway switch in this layer starts broadcasting and sending timing packets, and all the timing information in this layer can pass through the transparent clock TC It is transmitted to all time nodes of this layer without error accumulation. Setting the gateway switch as the boundary clock BC can also block the flow of timing information between different levels, reduce the communication burden of lines and devices, and enhance the stability of the timing system. According to this method, the clock time calibration area is divided, and the time calibration information only needs to go through two layers of PTP time calibration domains when it is transmitted from the district and county-level backbone layer to the terminal equipment of its 10KV distribution network access layer. This not only ensures that the timing error is controlled within the minimum range, but also forms a wide-area multi-layer unified timing network that can be expanded arbitrarily.

Further preferably, a GPS device is installed on the gateway switch of the main station at the backbone layer, and a Beidou device is installed on the switchboards of the sub-stations. When the gateway switch of the master station cannot normally receive the message information of the precise clock device transmitted by the upper-level network, the time can be corrected according to the GPS device set on the gateway switch of the master station. It is not necessary for each station to be equipped with a GPS device. It can not only ensure the stability of the timing system, but also reduce the cost of the timing system; if the message information of the precise clock device transmitted by the upper-level network cannot be received normally, the GPS device of the gateway switch of the main station will also When a failure occurs, a new line can be formed through the protection switching mechanism, and the time can be adjusted through the Beidou device installed on the sub-station switch. Not all sub-station switches are equipped with a Beidou device. We can selectively set it according to needs. Reduce the cost of the timing system.

Further preferably, a first local clock is set on the first gateway switch of the access layer, and a second local clock is set on the second gateway switch. When the message information of the superior precise clock device cannot be received normally, the time is corrected through the local clocks set on the first gateway switch and the second gateway switch.

Further preferably, both the gateway switch of the main station and the switch of the sub-station adopt a three-layer industrial Ethernet switch. The first gateway switch, the second gateway switch and the access layer switch all use Layer 2 industrial Ethernet switches.

Further preferably, the substation switch and the access layer switch are set to a point-to-point transparent transmission mode. The purpose of setting the transparent clock TCs of the substation switch and the access layer switch as point-to-point (P2P) transparent clocks is to further reduce the communication burden of lines and devices. In point-to-point (P2P), the path delay jitter between adjacent devices is recorded in the node through fixed-period timing measurement. When the timestamp information sent by the master clock is transmitted to the slave clock, the entire path delay jitter and switch protocol The stack jitter is added to the master clock information. The slave clock only needs to accurately calculate the time error with the master clock to adjust itself according to the local time of the Sync message it receives, without sending Delay-Request or Delay Subsequent messages such as -Response are equivalent to the master clock sending time correction information to the slave clock in one direction, and the ping-pong method is no longer used. The E2E transparent clock is still equivalent to using the ping-pong method to measure the delay jitter of the entire path, and when the network topology changes (protection switching), the synchronization accuracy of the E2E transparent clock may have a large short-term deviation, which will cause the protection device to malfunction.

Further preferably, the priority of the clock source at the backbone layer is the upper-level network transmission precision clock device, the GPS device on the gateway switch of the main station, and the Beidou device on the substation switch in order from high to low. The priority of the clock source at the access layer from high to low is the upper-level network transmission precision clock device, the first local clock on the first gateway switch, and the second local clock on the second gateway switch.

The beneficial effects that the present invention has are:

The IEEE1588 timing synchronization system of the intelligent distribution network based on industrial Ethernet direct connection into the ring achieves the effect of high expansion of the timing network scale through a reasonable timing system layering, and reasonably selects the time node type to achieve calibration. When the number of levels is small, the cumulative error is small, the line and node loads are appropriate, and the access layer is well adapted to the effect of the direct connection into the ring structure. Use a variety of clock sources for backup, enhance the robustness of the system, and inject time sources at appropriate places, so that the backbone layer can save a lot of GPS time calibration devices. By prioritizing different clock sources, the clock signal of the upper communication node is the first level, the clock source of the main station is the second level, and the clock source of the substation is set as the third level, so that the system can always determine a time according to the quality of the time source through the BMC algorithm The source is used as the main clock for timing, and an appropriate clock source injection point is selected to reduce the number of clock sources at the backbone layer at the district and county levels. By setting the gateway switch at the access layer as BC, if time islands occur at the access layer, a unified clock for time islands can be established to minimize the impact.

The present invention adopts IEEE1588 technology, reuses the industrial Ethernet communication system, selects the appropriate clock node type through a reasonable timing system layering, and finally forms a precise clock covering all distribution network automation terminal nodes, upper-level or local master stations The source is the main clock, multiple clock sources are backup, can transmit accurate clocks step by step, automatically form a new clock tree when the network redundancy is switched, the accuracy is better than 1 microsecond, the expansion is good, and it is well adapted to the direct connection of the access layer The wide-area multi-layer unified distribution network timing network that enters the ring serves for the construction of a wide-area measurement and control system for smart distribution networks.

Description of drawings

Fig. 1 is a system structure topological diagram of the present invention;

Fig. 2 is a schematic diagram of layer-by-layer transmission of precise clocks in the present invention;

detailed description

Embodiments of the present invention are further described below in conjunction with accompanying drawings:

As shown in Fig. 1 and Fig. 2, the intelligent distribution network IEEE1588 timing synchronization system based on industrial Ethernet direct connection into the ring according to the present invention includes a backbone layer and an access layer, and is characterized in that: the backbone layer includes a main The station gateway switch and multiple sub-station switches, the master station gateway switch is connected to the upper-level network transmission precision clock device, the master station gateway switch and the sub-station switches are connected through a gigabit optical fiber interface to form a ring structure, and the access layer includes the first gateway switch, the second gateway Switches and multiple access layer switches, the first gateway switch and the second gateway switch are respectively connected to both sides of the sub-station switch through the 100M optical fiber interface, and then connected to the access layer switch to form a ring structure, the main station gateway switch, sub-station switch The station switch, the first gateway switch, the second gateway switch and the access layer switch are all connected to the power distribution terminal device. The master station switch, the first gateway switch and the second gateway switch are set as boundary clocks. The switch is set as a transparent clock, and the power distribution terminal device is set as an ordinary clock;

The steps of the IEEE1588 time synchronization method for intelligent distribution network based on industrial Ethernet direct connection into the ring are as follows:

1) The master station gateway switch at the backbone layer receives the clock source message from the upper-level network transmission precision clock device. By setting the master station gateway switch as a boundary clock, the master station gateway switch terminates the message after receiving the upper-level time message , and then the gateway switch of the master station updates the local clock according to the received information;

2) The main station gateway switch uses the updated local clock as the main clock, and sends the message information to other sub-station switches connected to the backbone layer and the power distribution terminal device connected to the main station gateway switch through the main clock port , the substation switches are all set as transparent clocks, update their own clocks after receiving the message information, and at the same time send the message information to the power distribution terminal device connected to the substation switch;

3) While the gateway switch of the master station transmits the message information to the switch of the substation, the timing clock of the gateway switch of the master station passes through the switch of the substation and sends it to the first gateway switch in the access layer. Between the two connected access layer switches, the timing clock of the gateway switch of the master station is sent to the first gateway switch and the second gateway switch at the same time, and both the first gateway switch and the second gateway switch are set as boundary clocks. The first gateway switch and the second gateway switch update the local clocks after receiving the message information, and send the updated local clocks as the master clock to the access layer switch connected to it and the first gateway switch and the second gateway switch. The power distribution terminal device connected to the switch at the access layer performs time calibration; if a ring is blocked between the second gateway switch and the sub-station switch, the timing clock of the master station gateway switch is transmitted to the access switch through the sub-station switch. The first gateway switch of the entry layer, after the first gateway switch completes the time synchronization, it acts as the master clock, and sends the message information to other access layer switches connected to it, the second gateway switch, and the access layer switch and the first gateway switch. The power distribution terminal device connected to the switch and the second gateway switch, and the access layer switch are all set as transparent clocks.

Among them, the main station gateway switch on the backbone layer is equipped with a GPS device, the sub-station switch is equipped with a Beidou device, the first gateway switch on the access layer is equipped with a first local clock, and the second gateway switch is equipped with a second local clock. Both the main station gateway switch and the sub-station switch adopt three-layer industrial Ethernet switches, and the first gateway switch, second gateway switch and access layer switch all use two-layer industrial Ethernet switches. Substation switches and access layer switches are set to point-to-point transparent transmission mode. The priority of the clock source at the backbone layer is the precise clock device transmitted by the upper-level network, the GPS device on the gateway switch of the master station, and the Beidou device on the switchboard of the sub-station. The priority of the clock source at the access layer is the upper-level network The precise clock device, the first local clock on the first gateway switch, and the second local clock on the second gateway switch.

working principle:

The distribution network communication system is divided into two layers, the backbone layer and the access layer. The communication network of the backbone layer covers the master station of the distribution network (city dispatching center) and the sub-stations of the distribution network (each substation). The connections between the switches of the master station and the substation all adopt the IEEE1588 protocol. As shown in Figure 1, as the backbone layer, the backbone network design uses a three-layer industrial Ethernet switch, which forms a ring network through Gigabit optical fiber interfaces, and enables dynamic routing protocols in the ring network to realize dynamic forwarding of data routing. The access layer is mainly used for the access of terminals at all levels of the 10KV distribution network, covering various switching stations, ring network cabinets, power distribution stations, and pole-mounted switches. The access layer is composed of Layer 2 industrial Ethernet switches in the area covered by each communication convergence point. Different corresponding sub-rings are divided according to the coverage area. This ring is directly connected to the ring, and the two ends of the ring are respectively The gateway switch is connected to the three-layer switch of the backbone network of the local communication convergence point, and the two gateway switches form a complete access ring by connecting all other switches of the same layer and the backbone layer switch.

In the large ring of the backbone layer, select the switch node located at the master station as the gateway switch of this layer, select the clock type as the boundary clock BC, and other nodes as the transparent clock TC (P2P mode). In the small ring at the access layer, select the gateway switch as the boundary clock BC, and other switch nodes as the transparent clock TC (P2P mode). The master station switch receives the precise clock transmitted by the upper-level network or the GPS precise clock source signal to correct the local clock of the node. The backbone layer switch of the master station uses the local clock as the master clock and sends the message to other sub-station switches connected to the backbone network. Since the substation switch is set as a transparent clock TC, its own clock does not update, which means that the school time packet sent by the main clock port passes through the transparent clock TC to reach the next transparent clock TC or the gateway switch of the access layer connected to it At the end of a time calibration cycle at this layer, a time calibration can be completed for all gateway switches of the access layer. After all the gateway switches at the access layer complete the time synchronization, they serve as the master clock and send the school time message to other connected switches or their own power distribution terminal equipment. The school time message passes through the connected transparent clock TC to the next transparent clock Clock TC or the power distribution terminal device connected to it. The division of the clock timing area and the node configuration are shown in Figure 2. According to this division and configuration mode, a wide-area multi-layer unified timing network can be formed.

Realization of backbone layer clock source injection and redundancy: the main clock of the backbone layer timing network is the communication interface of the gateway switch of the master station connected to the upper-level backbone network, through which the precise clock transmitted by the upper-level network is received and the local clock of the switch is synchronized. Then broadcast time correction to all BCs connected to the time correction network of this layer. The standby clock source is the GPS satellite synchronous time synchronization device connected to the gateway switch of the master station and the Beidou satellite synchronization time synchronization device connected to other sub-station switches of the backbone layer. The clock source priorities are respectively set as follows: the precise clock transmitted by the upper-level network, the GPS device on the gateway switch, the Beidou device on the backbone switch of the substation, and the local clock. When the main clock fails, the node automatically updates and switches to the secondary backup clock source through the BMC algorithm, making it the new main clock, thus forming a new timing tree. The backbone loop is disconnected at the logical link shown in the diagram through the network management system, forming a tree-like timing system.

Implementation of clock source injection and redundancy at the access layer: when the communication network is directly connected to the ring, set the two gateway switches as boundary clocks BC, where the priority of the first gateway switch is higher than that of the second gateway switch, so that the time is synchronized The formation of the tree will be more convenient to avoid school time conflicts. In the normal state, the precise clock is transmitted from the upper-level network to the first gateway switch to correct the time, and then it will adjust the time to all power distribution terminal devices OC and the second gateway switch. When ring protection occurs on the line, the precise clock transmitted by the upper-level network is used to correct the time of the gateway switches on both sides, and then they are used to correct the time of the respective connected PTP sub-domains. When the time is islanded, the gateway switch on one side is used as the main clock source to correct the time for all power distribution terminal devices OC and the other gateway switch. When the time island and line ring protection occur at the same time, it is equivalent to forming two time islands, each of which uses its gateway switch as the main clock source to correct the time.

The present invention adopts the hierarchical principle, regards each communication ring (including the large ring of the backbone layer and the small ring of the access layer) as a clock timing area, and selects a small number of switch node clock types in each clock timing area Set to BC, as the main clock in the local clock calibration area; other nodes set to TC. In this way, the system can achieve the effects of fewer levels of system time calibration, less error accumulation, and appropriate line and node loads. The technology is simple, the time accuracy is high, the dependence on GPS is small, the cost is saved, the expansion is good, the coverage area is wide, and it is very good. The adaptive access layer is directly connected to the loop, which can meet the time synchronization requirements of the smart distribution network.

Claims (8)

1. synchro system during an intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet, comprise backbone layer and Access Layer, it is characterized in that: backbone layer comprises a main website and closes mouth switch and multiple substations switch, main website closes mouth switch connection higher level nets biography precision clock device, main website closes mouth switch and substation switch is connected to form loop configuration by kilomega optic fiber interface, Access Layer comprises the first pass mouth switch, second closes mouth switch and multiple access-layer switch, first closes mouth switch and second closes mouth switch and is connected to substation switch two rear flank by 100,000,000 optical fiber interfaces and is connected with access-layer switch formation loop configuration again, main website closes mouth switch, substation switch, first closes mouth switch, second closes mouth switch is all connected Distributing Terminal Assembly with access-layer switch, main website closes mouth switch, first pass mouth switch and the second critical point switch configuration are boundary clock, substation switch and access-layer switch are set to transparent clock, Distributing Terminal Assembly is set to ordinary clock,

During intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet, synchronous method step is as follows:

1) main website of backbone layer closes mouth switch and receives the clock source message netting biography precision clock device from higher level, by being boundary clock by main website critical point switch configuration, main website closes after mouth switch receives higher level's time message and is terminated by this message, and then main website closes mouth switch according to received information updating local clock;

2) main website closes mouth switch using the local clock after renewal as master clock, by master clock port message information sent to and be connected to other substation switch on backbone layer and close with main website the Distributing Terminal Assembly that mouth switch is connected, substation switch is all set to transparent clock, after receiving message information, upgrade the clock of self, message information is sent to the Distributing Terminal Assembly be connected with substation switch simultaneously;

3) main website closes mouth switch while message information is communicated to substation switch, when main website closes the school of mouth switch, clock sends to first in Access Layer to close mouth switch through substation switch, if loop resistance breaks between two access-layer switch appearing at and be connected, when then main website closes the school of mouth switch, clock is sent to the first pass mouth switch and second simultaneously and closes mouth switch, first pass mouth switch and second closes mouth switch and is all set to boundary clock, first pass mouth switch and second closes after mouth switch receives message information and upgrades local clock respectively, send to coupled access-layer switch using the local clock after renewal as master clock and close mouth switch with first, the Distributing Terminal Assembly that second pass mouth switch is connected with access-layer switch is calibrated, if occur that loop resistance breaks between the second pass mouth switch and substation switch, when then main website closes the school of mouth switch, clock is perforated through substation switch and is sent to first of Access Layer and closes mouth switch, after first pass mouth switch deadline is synchronous, itself is as master clock, sent to by message information other access-layer switch connected, second to close mouth switch and close mouth switch and second with access-layer switch, first and close the Distributing Terminal Assembly that mouth switch is connected, access-layer switch is all set to transparent clock.

2. synchro system during intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1, is characterized in that: the main website of described backbone layer closes on mouth switch and arranges GPS device, substation switch is arranged Big Dipper device.

3. synchro system during intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1, it is characterized in that: first of described Access Layer closes on mouth switch and arranges the first local clock, the second pass mouth switch arranges the second local clock.

4. synchro system during intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1 and 2, is characterized in that: described main website closes mouth switch and substation switch all adopts three layers of industrial ethernet switch.

5. synchro system during the intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1 or 3, is characterized in that: described first closes mouth switch, second closes mouth switch and access-layer switch all adopts two layers of industrial ethernet switch.

6. synchro system during intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1, is characterized in that: described substation switch and access-layer switch are set to point-to-point transparent transmission mode.

7. synchro system during intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1 and 2, is characterized in that: the clock source priority of described backbone layer be followed successively by from high in the end higher level net pass precision clock device, main website closes the GPS device on mouth switch and the Big Dipper device on the switch of substation.

8. synchro system during the intelligent distribution network IEEE1588 school based on the direct-connected access ring of Industrial Ethernet according to claim 1 or 3, it is characterized in that: the clock source priority of described Access Layer is followed successively by higher level from high in the end and nets the first local clock passed on precision clock device, the first pass mouth switch, and second closes the second local clock on mouth switch.