Process Bus and Sampled Values Based Applications

Transcription

1 Process Bus and Sampled Values Based Applications Dr. Alexander Apostolov Los Angeles, CA

2 Page: 2 Analog Signal Processing in ISD Analog Input Module Function Module Rela Input Module Opto Input Module Multifunction ISD

3 Page: 3 Analog Signal Processing in ISD Function Module Data Bus Analog Input Module A/D Converter Multiplexer Analog Filters Analog Filters Analog Filters Input X-er Input X-er Input X-er

4 Page: 4 Distributed Functions Bay Computer P... Interface 8 Interface 8 Logical Connection 1 Logical Connection 2 R Protection IED R P Protection IED P Distributed function

5 Page: 5 Merging Unit

6 Page: 6 Merging Unit Delay

7 Page: 7 Time synchronization Time synchronization is essential to any event analysis system There are two common ways of synchronizing various devices to the same clock source: Synchronization over direct connection Network synchronization

8 Page: 8 IEC Time Synchronization Accomplished using SNTP Simple Network Time Protocol SNTP is in essence a subset of NTP (Network Time Protocol). NTP uses UTC (Universal Time Coordinated, Temps Universel Coordonné) as reference time. UTC is an official standard for the current time and evolved from the former GMT (Greenwich Mean Time).

9 Page: 9 IEC Time Synchronization The UTC second has been defined by the 13th General Conference of Weights and Measures in 1967 as "The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom."

10 Page: 10 Time synchronization SNTP accuracy is not sufficient for SAV time synchronization IEEE 1588 is the future standard

11 Page: 11 Distributed Analog Functions IF 4 TCTR Protection Device Analog Interface Unit IF 4 RDRE LC1 LC2 LCn IF 4 TCTR TVTR Analog Interface Unit TCTR TVTR TVTR Distributed analog function

12 Page: 12 Logical Interfaces Remote control (NCC) 10 7 Technical Services 1,6 FCT. A FCT. B 9 STATION LEVEL 1, PROT. CONTR. CONTR. PROT. Remote protection 2 2 BAY/UNIT LEVEL 4,5 4,5 Remote protection Process Interface PROCESS LEVEL Sensors Actuators HV Equipment

13 Page: 13 Waveform Recording Based on Sampled Measured Values TCTR TVTR Data Set and SAV Formatting Merging Unit Recording IED Waveform Recording Function SAV /2

14 Page: 14 Sampled Measured Values SendSMVMessage (Communication mapping specific) Transmission Buffer ACSI Sample.req Local issue DATA-SET Member Member Member Publisher DATA:SAV cf-attr DO dc-attr cf-attr DO dc-attr cf-attr dc-attr MX attr MX attr MX attr FCDA1 FCDA2 FCDA3 Control Buffer SVC MemberReference ( = Functionally constraint DATA- ATTRIBUTE)

15 Page: 15 Recording IED

16 Page: 16 Distributed Recording System

17 Page: 17 RDRE Logical Node Data Objects

18 Page: 18 Object Model Mapping RDRE RADR RBDR

19 Page: 19 Distributed Recording System

20 Page: 20 Introduction IEC is now an approved international standard It allows the development of a new generation of distributed applications Distributed analogue values applications are analysed in this paper Devices conforming with the new communications standard are available from multiple vendors

21 Page: 21 Ethernet Frame Pre SFD DA SA Length Type MAC Data + Pad FCS bytes 4 Pre: The Preamble is an alternating pattern (7 bytes) of 1 and 0 that tells receiving stations that a frame is coming SFD: Start-of-frame delimiter (1 byte: ) indicating that the next bit is the left-most bit in the left-most byte of the destination address. DA: Destination address (6 bytes) identifies which station(s) should receive the frame SA: Source addresses (6 bytes) identifies the sending station

22 Page: 22 Ethernet Frame Pre SFD DA SA Length Type MAC Data + Pad FCS bytes 4 Length Type: Number of MAC-client data bytes that are contained in the data field of the frame MAC Client Data: A sequence of n bytes (46=< n =<1500) of any value. (The total frame minimum is 64 bytes). The Pad contains (if necessary) extra data bytes in order to bring the frame length up to its minimum size. A minimum Ethernet frame size is 64 bytes from the Destination MAC Address field through the Frame Check Sequence. FCS: The Frame Check Sequence is a 32-bit cyclic redundancy check (CRC) value

23 Page: 23 Addressing Modes Unicast communication takes place over the network between a single sending IED and a single receiving IED. The Destination Address identifies a unique device that will receive the Ethernet frame. Multicast is the addressing mode in which a given frame is targeted to a group of logically related IEDs. In this case the Destination Address is the Multicast Address, also called a "group" address.

24 Page: 24 Addressing Modes Broadcast is the mode when an IED is sending a frame to all devices connected to the substation network. The Destination Address in this case is a Broadcast Address - a multicast address identifying the group of all devices on a network - all 1 bits. The Broadcast Domain includes all network segments joined together by bridges.

25 Page: 25 Logical Interfaces IF1: protection-data exchange between bay and station level IF2: protection-data exchange between bay level and remote protection IF3: data exchange within bay level IF4: CT and VT instantaneous data exchange (especially samples) between process and bay level IF5: control-data exchange between process and bay level

26 Page: 26 Logical Interfaces IF6: control-data exchange between bay and station level IF7: data exchange between substation (level) and a remote engineer s workplace IF8: direct data exchange between the bays especially for fast functions like interlocking IF9: data exchange within station level IF10: control-data exchange between substation (devices) and a remote control center

27 Page: 27 Optical CT Interface

28 Page: 28 Transmission of Sampled Values The transmission of sampled values requires special attention with regard to the time constraints. The model provides transmission of sampled values in an organized and time controlled way so that the combined jitter of sampling and transmission is minimized to a degree that an unambiguous allocation of the samples, times, and sequence is provided. The model applies to the exchange of values of a DATA-SET (DATA of the common data class SAV).

29 Page: 29 Transmission of Sampled Values The information exchange shall be based on a publisher/subscriber mechanism. The publisher shall write the values in a local buffer at the sending side. The subscriber shall read the values from a local buffer at the receiving side. A time stamp shall be added to the values, so that the subscriber can check the timeliness of the values. A sampled value control (SVC) in the publisher shall be used to control the communication procedure.

30 Page: 30 Sampled Measured Values Based Model TCTR TVTR MMXU Merging Unit Data Set and SMV Formatting Relay Output Module Protection LN Protection ISD SMV /2

31 Page: 31 Sampled Measured Values

32 Page: 32 Transmission of Sampled Values The transmission of sampled values using multicast (MULTICAST-SAMPLE-VALUE CONTROL- BLOCK MSVCB) shall be based on configuration in the publishing device. To support self-descriptive capabilities, any client may read the attributes of the sampled value control instance. Authorized clients may modify attributes of the sampled value control.

33 Page: 33 Transmission of Sampled Values The data exchange shall be based on the multicast application association.

34 Page: 34 Transmission of Sampled Values

35 Page: 35 Transmission of Sampled Values The transmission of sampled values using unicast (UNICAST-SAMPLE-VALUE- CONTROL- BLOCK MSVCB) shall be based on two-party application associations. The subscriber shall establish the association with the producer. The subscriber may then configure the class and enable the transmission of the sampled values with the attribute SvEna. When the association is released, the transmission of the sampled values shall stop and the instance of the control class shall be released.

36 Page: 36 Distributed Analog Functions Protection Device Interface 4 TCTR PDIF Logical Connection n Analog Interface Unit TVTR Interface 4 Interface 4 TCTR Logical Connection 1 Analog Interface Unit TVTR Logical Connection 2 TCTR Analog Interface Unit TVTR Distributed analog function

37 Page: 37 Disturbance Recording

38 Page: 38 Transmission systems - waveform record

39 Page: 39 SAV Waveform Recording Object Model TCTR TVTR RADR Pxxx RDRE XCBR RBDR

40 Page: 40 RDRE Logical Node Data Objects

41 Page: 41 Object Model Mapping RDRE RADR RBDR

42 Page: 42 CT Saturation

43 Page: 43 CCVT 3rd Harmonic

44 Page: 44 Non-conventional Sensor Interface

45 Page: 45 Optical CT

46 Page: 46 Protection Applications Based on SAV Process Merging Unit Protection ISD Analog Sensor Sensor Module Interface Module Interface Module Function Module Outputs Module Status Sensor Input Module Interface Module Process Control Process Control Interface Unit Process

47 Page: 47 Interoperability Demo at CIGRE 2004

48 Page: 48 Interoperability Demo at CIGRE 2004

49 Page: 49 Mapping to IEC : 9 The mapping provides the capability to concatenate more than one ASDU into one APDU before the APDU is posted into the transmission buffer. The numbers of ASDUs which will be concatenated into one APDU are configurable and related to the sample rate. APCI (Application Protocol Control Information) ASDU s (Application Service Data Unit) Tag Length No. of ASDUs (UI16) ASDU 1 ASDU 2 ASDU n APDU (Application Protocol Data Unit) IEC 098/04