C Dr.-Ing. Abdalkarim Awad Informatik 7 Rechnernetze und Kommunikationssysteme

Transcription

1 C Informatik 7 Rechnernetze und Kommunikationssysteme

2 Measures Voltage, Current, phase PMU1 IEEE C WAN PDC Historian Phasor Data Concentrator HMI App1 PMU2 APn Bay1 Bayn LAN e.g., DNP3 Modbus IEC60870 Substation Automation System WAN Command Data e.g., DNP3 Modbus IEC60870 PDC-Phasor Data Concentrator HMI -Human Machine Interface LAN -Local Area Network PMU -Phasor Measurement Unit Dr.- Ing. Abdalkarim Awad 2

3 Architecture SuperPDC PDC PDC PMU PMU PMU PMU PMU 3

4 Phasor Measurement Unit (PMU) The phasor measurement unit (PMU) is a power system device capable of measuring the synchronized voltage and current phasor in a power system. Synchronicity among phasor measurement units (PMUs) is achieved by same-time sampling of voltage and current waveforms using a common synchronizing signal from the global positioning satellite (GPS). 4

5 Phasor Data Concentrator (PDC) Each utility has its own Phasor Data Concentrator (PDC) to: Aggregate/align data from various PMUs based on time tag Measurements from each utility s PDC is sent to the Central Facility: Where the measurements are synchronized across utilities 5

6 OpendPDC Complete set of applications for processing streaming time-series data in real-time Measured data is gathered with GPS-time from multiple input sources, time-sorted and provided to user defined actions, dispersed to custom output destinations for archival The openpdc implements a number of standard phasor protocols which can be used to receive data from devices. The supported protocols:ieee C37.118, IEEE 1344, BPA PDCstream, FNET, SEL Fast Message, 6

7 PMU Connection Tester Use the PMU Connection Tester to verify that a data stream from synchrophasor measurement device is being successfully received. The PMU connection tester supports several phasor data protocols IEEE C37.118, IEEE

8 C

9 Example of frame transmission order The SYNC word is transmitted first and CHECK word last. Two- and four-byte words including integer and floating-point numbers are transmitted most significant byte first (network or big endian order). All frame types use this same order and format. 9

10 Required PMU reporting rates 10

11 Word definitions common to all frame types 11

12 Word definitions common to all frame types 12

13 Sync (2 bytes) Frame synchronization word. Leading byte: AA hex Second byte: Frame type and Version, divided as follows: Bit 7: Reserved for future definition Bits 6 4: 000: Data Frame 001: Header Frame 010: Configuration Frame 1 011: Configuration Frame 2 100: Command Frame (received message) Bits 3 0: Version number, in binary (1 15), version 1 for this initial publication. 13

14 Word definitions common to all frame types 14

15 Example A PMU sent a packet that starts with following four bytes (decimal) 170,49,1,198 What is the 170? Determine the type of frame? Data Configuration Command header What is the size of the frame? 15

16 Example 170=0xAA (0x mean hexadecimal) It is the SYNC byte 49=0x31= b It is a configuration frame (Config-2) and the version (1) Then comes the two bytes size Size=198+1*256=

17 Configuration frame 17

18 Configuration frame 18

19 Word definitions unique to configuration frame 19

20 To send a value (e.g., Phasor) It is possible to send it as a float Or to send it as integer, But then, if the number has a fraction part. We need to scale it For example, to send as 16 bit integer Scale it e.g 1000*18.45=18450 At the receiver side: we convert it back using the same scale 18450/1000=18.45 In C37.118, PhasorMag=PHUNIT*

21 FORMAT (2 Bytes) Data format in data frames, 16-bit flag. Bits 15 4: Unused Bit 3: 0 = FREQ/DFREQ 16-bit integer, 1 = floating point Bit 2: 0 = analogs 16-bit integer, 1= floating point Bit 1: 0 = phasors 16-bit integer, 1 = floating point Bit 0: 0 = phasor real and imaginary (rectangular), 1 = magnitude and angle (polar) 21

22 PHUNIT (4 bytes) Conversion factor for phasor channels. Four bytes for each phasor. Most significant byte: 0 = voltage; 1 = current. Least significant bytes: An unsigned 24-bit word in 10 5 V or amperes per bit to scale 16-bit integer data. (If transmitted data is in floating-point format, this 24-bit value should be ignored.) 22

23 Example Explain the following two bytes for FORMAT field First byte (MSB)= 0 Second byte=8 So we have Bit 0=0 phasor real and imaginary (rectangular) Bit1=0 phasors 16-bit integer Bit2=0 analogs 16-bit integer Bit3=1 FREQ/DFREQ 32 bit float 23

24 24

25 Data Frame Data frame organization 25

26 PHASORS(4/8) 16-bit integer values: Rectangular format: Real and imaginary, real value first 16-bit signed integers, range to Polar format: Magnitude and angle, magnitude first Magnitude 16-bit unsigned integer range 0 to Angle 16-bit signed integer, in radians 104, range to

27 PHASORS(4/8) 32-bit values in IEEE floating-point format: Rectangular format: Real and imaginary, in engineering units, real value first Polar format: Magnitude and angle, magnitude first and in engineering units Angle in radians, range π to +π 27

28 FREQ(2/4) Frequency deviation from nominal, in millihertz (mhz) Range nominal (50 Hz or 60 Hz) to Hz 16-bit integer or 32-bit floating point. 16-bit integer:16-bit signed integers, range to bit floating point: actual frequency value in IEEE floating-point format. 28

29 Example If the voltage is Determine the content of the PHASORS bytes for the same FORMAT in the previous example and the PHUNIT has the following 4 bytes Based on the format field, we have to send the phasors as 16 bit Byte0=00 (most significant Byte) Byte1=00 Byte2= Byte3=175 PHUNIT=47* =

30 Example Vr= Vi=0 Before sending, we have to scale the value ScaledVr=Vr*100000/12207=20729 This value is 16 bit We have to send each byte ScaledVr=20729=0x50F9 ScaledVi=0=0x

31 Example We have to send the real part and then the imaginary part, therefore Fist byte=0x50 Second byte=0xf9 Third byte=0x00 Forth byte=0x00 31

32 Cyclic redundancy codes (CRC) CRC-CCITT g(x) = x 16 + x 12 + x

33 Example build the configuration frame for the following parameters: 1 phasor to send phasor data (voltage) in rectangular form using 16 bit integer, PHUNIT= analog channel to send data in 16 bit Nominal frequency=50 Hz Send the frequency deviation in 16 bit format Name of the PMU is My PMU Nr.1 Name of the phasor channel Voltage PMU Id is 1 Other fields can be filled with reasonable values 33

34 Example Send the frame to the PMU Connection Tester and verify that it is being received correctly. Send the voltage value frequency f= and Resend the frequency using 32 bit float (you have to change the configuration frame) 34

35 Bibliography IEEE C Standard Smart Grid: Technology and Applications, 2012, ISBN , Wiley, by Janaka Ekanayake, Kithsiri Liyanage, Jianzhong Wu, Akihiko Yokoyama, Nick Jenkins Smart Grid : Applications, Communications, and Security by Lars T. Berger and Krzysztof Iniewski Hamed Mohsenian-Rad, Communications & Control in Smart Grid (Slides) Computer Networks A Top-Down Approach (Slides) 35