Based on the intelligent grid terminal plug and play access distribution monitor network method of NFCTechnical field
The invention belongs to intelligent grid terminal plug and play field, relate to NFC technique, particularly relate to a kind of access of the intelligent grid terminal plug and play based on NFC distribution monitor network method.
Background technology
Along with the development of information technology and sensor technology, traditional power network and information network constantly merge, and form the intelligent grid being exchanged for final purpose with rational energy gradually.Power network and information network are combined closely, and have two-way flow, for the energy exchange of height of formation automation and extensively distribution lays the foundation.Intelligent grid is towards distributed future development, the microgrid with information interchange between the collection of sheet internal information and sheet becomes the core of intelligent grid development, and the terminal in microgrid, especially distributed power source steadily accesses power distribution network especially needs the communication technology and power technology common guarantee.The communications monitor system of power network can be monitored the voltage of distributed power source access procedure and electric power, adjusts it and meritorious exert oneself and idlely to exert oneself, be conducive to whole process smooth steady.
Intelligent grid terminal plug and play access distribution monitor net is the trend of following intelligent grid development, current wireless intelligence sensor plug and play technique Main Basis IEEE1451 standard, by standard air interfaces as communications such as IEEE802.11, Bluetooth, ZigBee and 6LoWPAN.Above wave point mainly distributes to the different frequency channels of transducer, and facility information is carried out standardization, the TEDS of forming device, thus realizes automatically identifying and marking equipment, reaches the effect of transducer plug and play.
There are some difficult problems in current intelligent grid terminal plug and play access distribution monitor net, mainly comprising wherein in the communication technology take intelligent electric meter as the more and comparatively dense of the terminal quantity of representative, the channel quantity only relying on frequency to distribute is limited, cannot meet intelligent grid terminal requirements.In addition, because wave point is all exposed in open space, there is larger potential safety hazard.
Summary of the invention
The present invention is directed to the present situation that existing wireless intelligence sensor plug and play technique cannot meet intelligent grid terminal requirements, a kind of wireless plug and play method based on NFC technique ad hoc mode is proposed, can be supplied to the radio access interface that intelligent grid terminal is enough, plug and play process is simple, access speed is fast.Technical scheme of the present invention is as follows:
A kind of access of the intelligent grid terminal plug and play based on NFC distribution monitor network method, adopt NFC point-to-point communication pattern, design intelligent grid terminal, terminal type comprises intelligent electric meter, photovoltaic generating system, energy-storage system, cooling heating and power generation system, fuel cell and charging system for electric automobile, adopt the sensor electrical subdatasheet TEDS regularly associating matching mechanisms foundation and be used for automatically identifying and identifying intelligent grid terminal, comprise following several aspect:
1) monitoring network access point and terminal are all equipped with NFC label respectively, when not connecting, are all in the Target state in NFC ad hoc mode;
2) when terminal prepares access monitoring network access point, the application of access monitoring network is triggered; Terminal detects NFC radio field around, if other NFC radio fields detected, then repeats radio field collision detection; Otherwise, the NFC module of terminal is switched to the Initiator state under aggressive mode;
3) terminal selects its global unique identification UUID as near-field communication mark NFCID3 content, identifies unique communication channel with the NFC module of monitoring network access point; Meta-TEDS, TransducerChannelTEDS and PHYTEDS of monitoring network access point loading terminal; Meta-TEDS mainly comprises UUID, terminal type; TransducerChannelTEDS mainly comprises maximum data rate, response wait time, maximum retransmission, minimal propagation delay, data transfer cycle; PHYTEDS mainly comprises transmission data format, physical unit, measuring range;
4) access point preserves terminal network configuration parameter, opens and regularly associates matching mechanisms; Terminal sends supervisory control system state and measurement data, or terminal receives the instruction of monitoring network change SOT state of termination; If tc is the association cycle, ts is the time limit of shaking hands, and ti maximumly accesses the time limit again, then regularly associate matching mechanisms as follows:
A. when transfer of data or Monitoring and Controlling, terminal and access point remain Frame and control frame transmits, comprise NFCID3 field in each NFC data frame and control frame, namely all comprise the UUID of terminal, can judge that terminal and access point whether can proper communications according to this UUID;
B. in idle condition, terminal and access point all switch to Target state, and access point sends association handshake frames every the tc cycle to terminal, if terminal replys association handshake frames within the ts time, then terminal is connected with access point normally; Otherwise, again send association handshake frames more than access point after ts, send limited number of time if accumulative all failed, then judge that terminal and access point disconnect, reclaim its Internet resources;
C. in terminal power down or shift out in access point situation temporarily, if terminal is being less than in the ti time request access distribution monitor network again, then without the need to the TEDS of loading terminal again again, directly search in the parameter directly stored at access point according to the UUID of terminal, carry out resource distribution; If exceed ti again to access, then need again to be loaded into; Access point disconnects after more than the ti time with terminal, removes UUID, TEDS and other information of storing this terminal.
The present invention has the following advantages:
1) wireless plug and play channel quantity is many.In the method, wireless plug and play channel is by the UUID uniquely identified of terminal, and with compared with frequency separation communication channel, channel quantity increases greatly.
2) in certain physical space, access point DENSITY LIMIT value is larger.What determine access point density is the spacing that NFC label is arranged, due to NFC technique be greater than 25cm distance outer just without label between electromagnetic wave interfere with each other, therefore can place NFC label at a distance of comparatively short distance, thus raising access point density.
3) regularly association matching mechanisms can reduce the communication power consumption of access point and terminal.Regularly associate matching mechanisms owing to adopting, access point and terminal, in idle periods with when not needing to transmit handshake frames/reply handshake frames, all can switch to Target state, save power consumption.
4) there is unexpected power-down rebooting and again access in the short time after shifting out access point temporarily in terminal, regularly associates matching mechanisms and can ensure quick access.
Embodiment
The present invention is with reference to IEEE1451.5 standard, and namely radio communication and transducer electronic data sheet (WirelessCommunicationProtocolsandTransducerElectronicDat aSheets (TEDS) Formats) define the content of Meta-TEDS and TransducerChannelTEDS being applicable to intelligent grid terminal.The TEDS defined in IEEE1451.5 standard is simplified, and specifically provides intelligent grid terminal particular attribute content, first provide each table content below.
The Meta-TEDS contents table of table 1 terminal
The TransducerChannelTEDS contents table of table 2 terminal
The PHYTEDS content of table 3 terminal
The table 4 terminal type amount of enumerating definition list
| Key assignments | Definition |
| 0 | Invalid |
| 1 | Intelligent electric meter |
| 2 | Photovoltaic generating system |
| 3 | Energy-storage system |
| 4 | Cooling heating and power generation system |
| 5 | Fuel cell |
| 6 | Charging system for electric automobile |
| 7-255 | Retain |
Table 5 transmits the data format amount of enumerating
| Key assignments | Definition |
| 0 | Invalid |
| 1 | Intelligent electric meter power data form |
| 2 | Intelligent electric meter current data form |
| 3 | Intelligent electric meter voltage data format |
| 4 | Intelligent electric meter phase-angle data form |
| 5 | Intelligent electric meter frequency data form |
| 6 | DER power data form |
| 7 | DER current data form |
| 8 | DER voltage data format |
| 9 | DER phase-angle data form |
| 10 | DER frequency data form |
| 11 | DER mode data form |
| 11-255 | Retain |
Table 6 intelligent electric meter power data form
Table 7 intelligent electric meter current data form
| X phase current | Y phase current | Z phase current |
| 4 bytes | 4 bytes | 4 bytes |
Table 8 intelligent electric meter voltage data format
| X phase voltage | Y phase voltage | Z phase voltage |
| 4 bytes | 4 bytes | 4 bytes |
Table 9 intelligent electric meter phase-angle data form
| X phase phase angle | Y phase phase angle | Z phase phase angle |
| 4 bytes | 4 bytes | 4 bytes |
Table 10 intelligent electric meter frequency data form
| X phase frequency | Y phase frequency | Z phase frequency |
| 4 bytes | 4 bytes | 4 bytes |
Table 11DER mode data form
First above-mentioned each table is described.
Table 1 is the Meta-TEDS contents table of terminal, defines the substance of intelligent grid terminal, for registering intelligent terminal.Comprise the UUID of the monitoring module of intelligent grid terminal, generate unique identifier by the monitoring module production site longitude and latitude of intelligent grid terminal, time, thus ensure the uniqueness of its UUID.Terminal type field is used to register this terminal and belongs to which kind of type, specifically defines in table 4.Whether overall TEDS School Affairs is the School Affairs of Meta-TEDS all the elements, be used for checking field contents in transmitting procedure wrong.
Table 2 is TransducerChannelTEDS contents table of terminal.Message transmission rate field refers to intelligent grid terminal message transmission rate in communication process, and the speed that can select is 106kpbs, 212kpbs or 424kpbs.Response wait time field refers to the longest response stand-by period after a Packet Generation, and then start retransmission mechanism after exceeding, its unit is millisecond.Maximum retransmission refers to set out the maximum number of times retransmitted after retransmission mechanism for each packet.Minimal propagation delay refers to that individual data wraps in the minimum delay time in transmitting procedure, and unit is millisecond.Data transfer cycle refers to the interval time of adjacent twice transmission data, and unit is millisecond.Whether transmitter passage TEDS School Affairs is the School Affairs of TransducerChannelTEDS all the elements, be used for checking field contents in transmitting procedure wrong.
Table 3 is PHYTEDS of terminal, defines transfer of data relevant field.The measurement data that different terminal types can transmit is different, and the transformat of often kind of data is by transmitting data format definition, and specifically define in table 5, its physical unit is determined by physical unit field.The definition of physical unit is consistent with IEEE1451.2 standard.The scope of measuring range Field Definition transmission data, its physical unit and physical unit field determine.Whether physics TEDS School Affairs is the School Affairs of PHYTEDS all the elements, be used for checking field contents in transmitting procedure wrong.
Table 4 is the terminal type amount of enumerating definition lists, defines the key assignments that different types of terminals is corresponding.Terminal type comprises intelligent electric meter, photovoltaic generating system, energy-storage system, cooling heating and power generation system, fuel cell, charging system for electric automobile
Table 5 is the transmission data format amount of enumerating definition lists, defines the key assignments that different transmission data format is corresponding.Transmission data format comprises intelligent electric meter power data form, intelligent electric meter current data form, intelligent electric meter voltage data format, intelligent electric meter phase-angle data form, intelligent electric meter frequency data form, DER power data form, DER current data form, DER voltage data format, DER phase-angle data form, DER frequency data form, DER mode data form.Wherein intelligent electric meter power, electric current, voltage, phase angle and frequency specifically define with reference to table 6-10, and DER power, electric current, voltage, phase angle and frequency to be specifically defined in intelligent electric meter similar, do not enumerate one by one.DER mode data form specifically defines with reference to table 11.
Table 6 is intelligent electric meter power data forms.
Table 7 is intelligent electric meter current data forms.
Table 8 is intelligent electric meter voltage data formats.
Table 9 is intelligent electric meter phase-angle data forms.
Table 10 is intelligent electric meter frequency data forms.
Table 11 is DER mode data forms.
Concrete implementation step is as follows.
Access point in the present invention and terminal all need to possess NFC label module on physical hardware, wherein terminal is mainly divided into two kinds, one is the simple intelligent electric meter of function, another kind is distributed energy (DistributedEnergyResource, the DER) system of supervisory control system complexity.DER intelligent monitoring terminal is mainly divided into following a few class: photovoltaic generating system, energy-storage system, cooling heating and power generation system, fuel cell and charging system of electric powercar.Needing by the NFC label in terminal being pressed close to the NFC label on access point, completing terminal access distribution monitor net.
In access procedure, its UUID of terminal carrys out unique identification communication channel, by being loaded into its TEDS, access point is identified and marking terminal classification automatically.After terminal access, open regular relation mechanism, the communication of terminal at data transfer phase, idle phase can be maintained, ensure that terminal accesses at short notice again fast because of fortuitous event power-down rebooting or the situation such as to remove temporarily.Concrete steps are as follows:
1) monitoring network access point and terminal are all equipped with NFC wave point respectively, start initialization, select aggressive mode and transmission speed to be 106kpbs or 212kpbs or 424kpbs, switch to Target state, and access point waits for that terminal initiates access request.
2) terminal is before access, the NFC label of self should be alignd with access point NFC label and be placed with, and within distance remains on 10cm, presses the physical button that exterior of terminal controls access, triggers the application of access monitoring network.Terminal switch is Initiator state, terminal fills NFCID3 field with the UUID of oneself, test current external RF field, if other RF fields detected, then do not activate the RF field of oneself, if neither one external RF field is detected, then activate the RF field of oneself, and then activate the Target label of access point.
3) terminal NFCID3 and monitoring network access point match, thus mark unique communication channel.Meta-TEDS (the overall TEDS of loading terminal, in table 1), TransducerChannelTEDS (transmitter passage TEDS is in table 2) and PHYTEDS (physics TEDS, in table 3), identify kind and the measurement data form of the terminal of access.
4) preserve UUID and TEDS of terminal, and unlatching regularly associates matching mechanisms.Monitor channel starts, and terminal sends monitoring module state and measurement data, or terminal receives the instruction of monitoring network change SOT state of termination.Regular association matching mechanisms is described in detail as follows, and wherein tc refers to the association cycle, and ts refers to the time limit of shaking hands, and ti refers to and maximumly again accesses the time limit.
A. when transfer of data or Monitoring and Controlling, terminal and access point remain Frame and control frame transmits, comprise NFCID3 field in each NFC data frame and control frame, namely all comprise the UUID of terminal, can judge whether terminal and access point can proper communications according to this UUID.
B. in idle condition, terminal and access point all switch to Target state, and access point sends association handshake frames every the tc cycle to terminal, if terminal replys association handshake frames within the ts time, then terminal is connected with access point normally; Otherwise, again send association handshake frames more than access point after ts, if accumulative transmission 3 times is all failed, then judges that terminal and access point disconnect, reclaim its Internet resources.
C. in terminal power down or shift out in access point situation temporarily, if terminal is being less than in the ti time request access distribution monitor network again, then without the need to the TEDS of loading terminal again again, directly search in the parameter directly stored at access point according to the UUID of terminal, carry out resource distribution; If exceed ti again to access, then need again to be loaded into.Access point disconnects after more than the ti time with terminal, removes UUID, TEDS and other information of storing this terminal.