How To Communicate With A Smart Meter And Collector (Mum)

Transcription

1 Power Line: control and communication Sistemi e strumenti per l'automazione, A. Flammini, AA

2 Phasor mesurement A given sinusoidal signal 2 2 x( t) = ak cos( kω t) + bk sin( kω0t) = ak + bk cos( kω0t + 0 φ) and its phasor X k = a 2 k + b 2 2 k e jφ = 1 2 ( a jb ) k k Signal Phasor Sistemi e strumenti per l'automazione A. Flammini, AA

3 Phasor Measurement Unit Anti-aliasing filter GPS to synchronize PMUs samples and to generate a servo clock 60 samples per cycle DFT analysis: Synchronous/asynchronous sampling Separation of fundamental harmonic N samples Analog Input 60 samples per cycle GPS receiver Phase locked oscillator Modem Phasor Anti-aliasing filters 16 bit A/D converter Phasor microprocessor Fondamenti di elettronica digitale, A. Flammini, AA

4 PMU on Power Line Distributed synchrophasor measurements wider view of the power system will require synchronized phasor measurements control to voltage instability prediction transient stability monitoring PMU in primary substation Timestamped phasor are collected Their use is under study PMU data concentrator Optimal placement of PMUs in power systems to enhance state estimation is a problem that needs to be solved Primary substation Secondary substation H/M M/L PMU M/L H/M PMU M/L Fondamenti di elettronica digitale, A. Flammini, AA

5 Smart Meter What is a smart meter A new electricity (and not also) meter which can eliminate many labor-intensive business process Availability of power using information in every hour, or even in every second (typically every 15 minutes) Bidirectional communication (data and commands) The part of Advanced Metering Infrastructure ( AMI ) Smart metering is not only electricity, but also gas, water and heat Sistemi e strumenti per l'automazione A. Flammini, AA

6 Smart Metering Why smart metering: Decrease power wasting caused by meter Greenhouse effect Economize power by change our way in using power real-time registration of the consumes possibility to read the meter both locally or remotely remote limitation of the throughput through the meter, even cessation of the utility if necessary interconnection with other networks in order to display and collect data control smart appliances Sistemi e strumenti per l'automazione A. Flammini, AA

7 Microgrid communications Data transmission between meter and collector wired PLT (Power Line Transmission): IEC61334, ANSI/IEA 709.1/2, LonWorks (Echelon C.), PRIME (STMicroelectronics), G3-PLC (Maxim), IEEE P BPL (Broadband Power Line communication) IEEE 1901, HomePlug Green PHY M-bus (EN /2/3) wireless IEEE ZigBee Smart Energy Protocol Wireless M-bus secure in any case (privacy) Smart meter Data collector Smart meter Smart meter Sistemi e strumenti per l'automazione A. Flammini, AA

8 State of Art Italy: 1 st large smart meter deployment. Telegestore Project installed more then 30 million of new smart meters since New legislation (direttiva MID 204/22/EC) will force to replace all old gas meter with smart gas meter, final version of legislation is being defined. UK: Many smart gas sensors have already been placed in past. Now the legislation is leading the utility (and costumer) to replace both electricity and gas meter for all costumers. USA: California are leading smart meter market in USA. Until 2006, 9 million of meter was retrofitted with microprocessor. Great investments on AMI. China: As of 2011, SGCC (State Grid Corporation of China) has installed 36 million smart meters and announced it will install over 300 million smart meters by the end of 2015 Sistemi e strumenti per l'automazione A. Flammini, AA

9 Advanced Meter Infrastructure AMI AMM AMR AMI component AMR (Automated Meter Reading): based on smart metering. Collects data from smart meters. Take care about the communication between meters and concentrator. AMM (Automated Meter Management): allows bidirectional communication in the smart meters network. This remote management performs sending of commands and messages to the meters and is able to download data. Fondamenti di elettronica digitale, A. Flammini, AA

10 AMI features Infrastructure of metering systems Automates most of the metering centred repetitive activities Collects granular consumption data to deploy dynamic pricing mechanisms New payment and customer service options Control of electrical load within the home and or businesses to improve system diversity Residential Metering meter meter WL/PLC concentrator GSM/GPRS Metering system platform Exchange Infrastructure Technology Platform Industrial Metering meter Fondamenti di elettronica digitale, A. Flammini, AA

11 Open Metering System (OMS) Hierarchical architecture AMM (Automated Meter Management): processes metering data for billing and balancing MUC (Multi Utility Communication): collects, analyzes and processes data from meter METER / ACTUATOR: provides data to the system AMM Tertiary Communication MUC MUC MUC MUC METERS Primary Communication Note: a secondary communication has been planned for repeater Fondamenti di elettronica digitale, A. Flammini, AA

12 OMS: Communication Levels Primary Communication (among MUC dev. and meter) Wired: M-bus wired (EN /2), pull mode Wireless: wm-bus (EN ), push mode (only T1/2 MUC e S1/2 allowed) PLC (Power Line Communication) future option Secondary Communication MUC repeater Communication range extension Tertiary communication (among AMM end MUC dev.) AMM TCP/IP v.4 or higher meter MUC meter Fondamenti di elettronica digitale, A. Flammini, AA

13 OMS: Application Layer Primary Communication (close to the meter) M-bus data coding (EN ) : -DIF (Data Information Field), data representation and length. -VIF (Value Information Field), representation unit and multiplier of the value. Optional field Extension (DIFE and VIFE). DLMS/COSEM (Device Language Message Specification/ COmpanion Specification for Energy Metering; IEC ): communication entity definition and data format. Structured data form SML (Smart Message Language) Sym 2 project, german standard of electricity communication data. Can be encapsulated in other protocol (TCP/IP, M-bus). COSEM can be integrated in SML protocol Tertiary communication DLMS/COSEM Fondamenti di elettronica digitale, A. Flammini, AA

14 M-bus Standardization M-bus is typically used for metering applications. This standard is defined in EN (Communication system for meter and remote reading of meters) EN Data Exchange: base communication between meters and central data collector; A view of communication system EN Physical and data link layer: physical specification for wired data transmission; Transmission protocol data description EN Application layer: application protocol for compatibility of different producer product EN Wireless meter readout (868MHz 870MHz SRD band): wireless M-bus communication. Physical and Data link EN Relaying: range extension; repeater Fondamenti di elettronica digitale, A. Flammini, AA

15 M-bus Wired bus communication, distance between slave and repeater up to 350 m Remote powering of the slaves: 1->36V and 0->24V Segmentation: repeaters allow to separate zones Cable: two-wire standard telephone cable From 300 to 9600 baudrate at 350 m length, in standard realization and maximum of 250 slaves Fondamenti di elettronica digitale, A. Flammini, AA

16 M-bus: telegram format Single Character This format consists of a single character and serves to acknowledge receipt of transmissions. Short Frame This format with a fixed length besides the C and A fields includes the check sum (this is made up from the two last mentioned characters), and the stop character 16h. Long Frame With the long frame, after the start character 68h, the length field (L field) is first transmitted twice, followed by the start character once again. After this, there follow the function field (C field), the address field (A field) and the control information field (CI field). The L field gives the quantity of the user data inputs plus 3 (for C,A,CI). After the user data inputs, the check sum is transmitted, which is built up over the same area as the length field, and in conclusion the stop character 16h is transmitted. Control Frame The control sentence conforms to the long sentence without user data, with an L field from the contents of 3. The check sum is calculated at this point from the fields C, A and CI. Fondamenti di elettronica digitale, A. Flammini, AA

17 M-bus: field meaning L-field: length of the packet without L and CRC fields C-field: control frame field, function field. Identify the type of frame (SEND, CONFIRM, REQUEST, o RESPOND). The function field specifies the direction of data flow, and is responsible for various additional tasks in both the calling and replying directions A-field: address field. The address field serves to address the recipient in the calling direction, and to identify the sender of information in the receiving direction. The size of this field is one Byte, and can therefore take values from 0 to 255 CI-field: packet header, specify data type in the application data payload Check Sum: 2 bytes control frame Fondamenti di elettronica digitale, A. Flammini, AA

18 wm-bus SubGHz frequency band (868MHz 869MHz) 2-FSK modulation Manchester or 3 out of 6 encoding Up to kbit/s Packet length up to 256 bytes M-bus implements 1,2 and 7 ISO/OSI stack layers One way (T1, S1) or bidirectional (T2, S2) communication Typically meter starts communication Data coding: M-bus codification (EN ): DIF (Data Information Format); VIF (Value Information Format) COSEM/DLMS (EN ), mandatory for tertiary communication: OBIS (Object Identification System) structured data AES-128 encryption Fondamenti di elettronica digitale, A. Flammini, AA

19 wm-bus: type of communication Type Directivity description S1 S1-m Unidirectional Unidirectional S2 Bidirectional Bidirectional version of S1 T1 T2 R2 Unidirectional Bidirectional Bidirectional In stationary mode, the metering devices send their data several times a day. The data collector may save power as meter send a wake up signal before transmission Same as S1 but collector can not enter in power save mode In the frequent transmission mode, the metering devices periodically send their data to collector. Interval in the order of several seconds or minutes (faster, less power consumption) Bidirectional version of T1. The data collector may request dedicated data from the metering devices The frequent receive mode permits multiple metering devices not to interfere due to frequency multiplexing Fondamenti di elettronica digitale, A. Flammini, AA

20 wm-bus: cycle of communication S2: meter periodically sends its data T2: meter periodically starts a communication cycle In the unidirectional version only Data Collector transmits R2: meter periodically listens channel waiting for a preamble Fondamenti di elettronica digitale, A. Flammini, AA

21 wm-bus: telegram format WL packet structure optional block to add to telegram related to message length L-field: length of the packet without L and CRC fields C-field: control frame field. Identify the type of frame (SEND, CONFIRM, REQUEST, o RESPOND) M-field: producer code field. A-field: address field. 6 bytes unique address for each CI-field: packet header, specify data type in the application data payload CRC: 2 bytes control frame Fondamenti di elettronica digitale, A. Flammini, AA

22 ZigBee Smart Energy Profile ZigBee smart energy profile components: Metering device Energy service interface In-premises display device Programmable Communicating Thermostat Device Load Control Device Non Range extender device Smart appliance device Prepayment terminal device AMI server ZigBee link Energy service interface ZigBee link meter ZigBee link ZigBee link Home Energy Management Console In home display ZigBee link Smart Appliance Fondamenti di elettronica digitale, A. Flammini, AA

23 ZigBee Smart Energy Profile 2.4 GHz and subghz channel frequency band (IEEE ) Client/server communication model The data exchanged depend on the scenario Security: AES-128 encryption; APS encryption UTC time representation for data resolution down to second Synchronization one time at day Tunneling protocol (provisionary and not certifiable) DLMS/COSEM IEC61107 ANSI C12 M-bus Climate Talk Fondamenti di elettronica digitale, A. Flammini, AA

24 ZigBee Supported Features Basic metering [measurements, historical info, etc], Text messages Demand Response (DR) and Load Control Pricing [multiple units & currencies, price tiers, etc.] Device support for Programmable Communicating Tstats (PCTs), Load Control Devices, Energy Management Systems, In Home Displays (IHDs), etc. Security to allow consumer only, utility only, or shared networks Fondamenti di elettronica digitale, A. Flammini, AA

25 Power Line Communication PLC (Power Line Communication) is technology of information transmission on power line cables Information signal travels on cable with power signal (50/60 Hz) Reduction of cables installation (electrical cables are already placed) Noise introduced by powered devices on network is problematic Band over 30 MHz is not allowed for electromagnetic emissions NarrowBand PLC (up to 500kHz) LonWorks (widely used thanks to Enel) PRIME G3-PLC IEC61334, ANSI/IEA 709.1/2 (not OFDM) BroadBand BPL (MHz) HomePlug Fondamenti di elettronica digitale, A. Flammini, AA

26 PLC Regulations International CENELEC Bands Narrowband(): A Band (3 khz-95khz): reserved to electrical utilities (under license) B Band (95 khz-125khz): for all applications without protocol C Band (125kHz-140kHz): reserved to home network systems, Access Protocol (CSMA / CA = Carrier Sense Multiple Access /Collision Avoidance) mandatory. D Band (140 khz-148.5khz): alarm and security system without protocol Higher narrowbands (up to 500kHz) seem to be open by new regulation Broadband is not regulated Regional National Fondamenti di elettronica digitale, A. Flammini, AA

27 PRIME PRIME (PoweRline Intelligent Metering Evolution): open, public and non-proprietary telecom solution focused on smart metering and smart grid PRIME Alliance: Advance Digital Design, Current Technologies International, Iberdrola, Landis & Gyr, ST Microelectronics, Usyscom, ZIV Medida Define low layers of a PLC narrowband data transmission system Fondamenti di elettronica digitale, A. Flammini, AA

28 PRIME: System Architecture PRIME system is composed of subnetworks, each of them defined in the context of a transformer station. A subnetwork is a tree with two types of nodes, the Base Node and the Services Nodes Base Node The Base Node is at the root of the tree and acts as master node that provides connectivity to the subnetwork. It manages the subnetwork resources and connections. There is only one Base Node in a subnetwork. Service Node Any other node of the subnetwork is a Service Node. Each of these nodes is one point of the mesh of the subnetwork. These nodes have two responsibilities: connecting themselves to the subnetwork and switching the data of their neighbors in order to propagate connectivity. Service Node Base Node Service Node Service Node Power line Fondamenti di elettronica digitale, A. Flammini, AA

29 PRIME Stack Layers The service-specific Convergence Sublayer (CS) classifies traffic associating it with its proper MAC connection. This layer performs the mapping of any kind of traffic to be properly included in MAC SDUs. It may also include payload header suppression functions. Multiple CSs are defined in order to accommodate different kinds of traffic into MAC SDUs. The MAC layer provides core MAC functionalities of system access, bandwidth allocation, connection management and topology resolution. It has been defined for a connection oriented Master-Slave environment, and optimized for low voltage power line environments. The PHY layer transmits and receives MAC PDUs between Neighbor Nodes. It is based on OFDM multiplexing in CENELEC A band and reaches up to 130 kbps raw data rate. Fondamenti di elettronica digitale, A. Flammini, AA

30 PRIME: Physical Layer OFDM (Orthogonal Frequency Division Multiplexing) modulation Subcarriers all contained in CENELEC A band (3kHz 95kHz) Up to 96 subcarriers Modulation adopted: Differential Phase Shift Keying (DPSK) in different implementations: DBPSK, DQPSK, D8PSK Optional FEC (Forward Error Correction) Fondamenti di elettronica digitale, A. Flammini, AA

31 PRIME: Frame Format Preamble: The use of OFDM symbols for the Preamble is not appropriate. Additionally, the preamble needs frequency agility to avoid that frequency selective attenuation could suppress it Header: just after the Preamble, 13 pilot subcarriers are inserted in each of the first 2 OFDM symbols to provide enough information to estimate the sampling start error and the sampling frequency offset Payload: DBPSK, DQPSK or D8PSK encoded, depending on the SNR available to achieve the desired BER. The MAC layer will select the best modulation scheme using information from errors in the last frames. The system will then configure itself dynamically to provide the best compromise between throughput and efficiency in the communication. This includes deciding whether or not FEC (convolutional coding) is used. Fondamenti di elettronica digitale, A. Flammini, AA

32 PRIME: MAC Layer Each node have 48 bits Mac address Master/Slave configuration oriented Medium access is both Time Division Multiplex (TDM) and CSMA/CA SCP: Base Node allocation needed CFP: Free access to medium Type of connection Unicast Broadcast Group-based multicast Fondamenti di elettronica digitale, A. Flammini, AA

33 G3-PLC G3-PLC: Maxim, Iberdrola, EDF, erdf, Itron, Texas Instruments Define low layers of a PLC narrowband data transmission system ARCHITECTURE Decentralized architecture, where the data concentrator acts as an application relay, with more or less autonomy. The exchanges at transport level in this case are limited to the dialogue between the meters and the concentrators Or to have a more centralized architecture in which the concentrator simply acts as a network gateway and the meters dialogue directly with servers. Fondamenti di elettronica digitale, A. Flammini, AA

34 G3-PLC Stack Layers The Metering application covers layers 5 to 7 in the OSI model. It will be noted that all these applications rely natively on UDP, but there is nothing to prevent the future introduction of Applications that use TCP. The 6LoWPAN adaptation sublayer enables an efficient interaction between the MAC and the IPv6 network layers. The MAC sublayer based on IEEE ; and the Adaptation layer based on RFC 4944: Transmission of IPv6 Packets over IEEE Networks (6LowPan). The PHY layer transmits and receives telegrams between nodes. It is based on OFDM multiplexing in CENELEC A band. 6LoWPAN is widely used also in wireless to have IPv6 over IEEE (e.g. ISA100) Fondamenti di elettronica digitale, A. Flammini, AA

35 G3-PLC: Physical Layer OFDM (Orthogonal Frequency Division Multiplexing) modulation Carriers frequency band in CENELEC A band (3kHz 95kHz), but also up to 180kHz (out of CENELEC up to 490kHz) Up to 36 subcarriers Modulation adopted: DBPSK, DQPSK Up to 34.1kbit/s FEC (Forward Error Correction) Fondamenti di elettronica digitale, A. Flammini, AA

36 G3-PLC: Telegram Format Ack frame and data frame format Preamble: used for synchronization FCH (Frame Control Header): control information for demodulation Data: Information transmitted with maximum length of 252 symbols Fondamenti di elettronica digitale, A. Flammini, AA

37 PRIME and PLC G3 (supported by IEEE1901.2) Fondamenti di elettronica digitale, A. Flammini, AA

38 PRIME and PLC G3 (supported by IEEE1901.2) G3, more powerful FEC PRIME, less complex FEC Fondamenti di elettronica digitale, A. Flammini, AA

39 LonWorks LonWorks (Local Operating Network): network platform developed by Echelon Corp., based on neuron chip Enel Telegestore project communication based on LonTalk, LonWorks communication protocol 60 million devices by 2006 Open protocol standard from 2009 (ISO/IEC ) Each LonWorks device must have single ID (sold by Echelon) Multiple standards International and open industry standard European standards China national standards Fondamenti di elettronica digitale, A. Flammini, AA

40 LonWorks: Neuron Chip Protocol Firmware (Layer 1-2) Protocol Firmware (Layer 3-6) Transceiver Optional External Memory Comm port Media Access CPU RAM / ROM EEPROM Network CPU RAM / ROM EEPROM I/O Conditioning I/O (Counters, Resources, Drivers, etc) RAM / ROM EEPROM Application CPU Xtal Power Regulator Neuron Chip Node Specific Program Fondamenti di elettronica digitale, A. Flammini, AA

41 LonTalk Protocol Media Twisted pair, powerline, radio frequency, fiber optics, coaxial cable Lowest data rate 610 bps Reliability Supports end-to-end acks with ARQ Broadcast acks also Medium access Proprietary collision prediction algorithm Collision detection on some media (e.g., TP) Optional priority feature Network management/applications SNVTs Standard Network Variable Types A key to interoperability Standardizes variables used to name and describe things and their states Maintained by LonMark International Fondamenti di elettronica digitale, A. Flammini, AA

42 LonTalk: Network Layer LonTalk protocol support a variety of topologies LonTalk protocol support physical layer repeaters as well as store and forward repeaters to repeat packets from one channel to another. The protocol also supports bridges to repeat all packets on the bridge s domain from one channel to another Fondamenti di elettronica digitale, A. Flammini, AA

43 LonTalk: Data Link and Physical Layer DATA LINK Error Detection (CRC) Flexible allocation of bandwidth Priority access mechanisms Graceful behavior under overload p-persistent CSMA Message collision avoidance Optional collision resolution, collision detection PHYSICAL FSK modulation Manchester encoding Spread spectrum (proprietary) or narrowband 10 Kbps, Up to 2000 m on clear line Fondamenti di elettronica digitale, A. Flammini, AA

44 HomePlug HomePlug Alliance: STMicroelectronics, Maxim, Marvel, SONY BPL (Broadband Power Line communication) standard from 2010 (IEEE 1901) HomePlug version: HomePlug 1.0, 14 Mbit/s HomePlug AV, 200 Mbit/s HomePlug AV 2, 600 Mbit/s 1.8 Gbit/s HomePlug Green PHY, 10 Mbit/s; designed for smart metering Fondamenti di elettronica digitale, A. Flammini, AA

45 HomePlug: System Architecture Fondamenti di elettronica digitale, A. Flammini, AA

46 HomePlug: Physical Layer Windowed OFDM Spectral notching for preamble, frame control and payload 917 carriers (excluding Amateur bands) Bit-loaded modulation: BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, 1024 QAM Optimum adaptation for each connection Turbo FEC for frame control, beacon, payload 16, 136 and 520 byte block sizes respectively Near capacity performance (1/2 db from Shannon Capacity) Channel interleaver for impulse noise and other PL impairments Diversity coding for reliable frame control, beacon and ROBO HP1.0 coexistence mode uses 1.0 frame control AV preamble can be detected by 1.0 devices 200 Mbps PHY channel rate 150 Mbps PHY information rate Fondamenti di elettronica digitale, A. Flammini, AA

47 HomePlug: MAC Layer Network managed by a Central Coordinator (CCo) Three access methods within a network: Beacon: Non-contention, CCo transmits Beacon in dedicated slot CSMA: Contention-based, exchange of priority-based user data and management messages, shared with HP 1.0 Contention-free: Only designated station transmits. QoS guarantee Beacon Period is divided into Regions Schedules specified in Beacons Different allocations are further specified in some Regions Beacon Period synchronous with AC line cycle Allocations: persistent, or non-persistent (valid for current Beacon Period only) Neighbor network coordination Sharing channel with other AV networks (MDUs) Fondamenti di elettronica digitale, A. Flammini, AA