PMU Communication Network Analysis

Transcription

1 PMU Communication Network Analysis what - why - how <=> with PMU existence CS620: New Trends in Information Technology Course Seminar Presentation By Gelli Ravikumar & Kedar Khandeparkar Roll No & Course Instructors Prof. Krithi Ramamritham & Prof. Purushottam Kulkarni Department of Electrical Engineering Indian Institute of Technology Bombay February 10, 2013

2 Outline Talk by Gelli PMU basics in nutshell PMU Communication Network Analysis - Discussing 2 papers Talk by Kedar PMU Communication Network Analysis - Discussing 2 papers PMU Communication Network Analysis Gelli Ravikumar 2 / 31

3 PMU Exam (Quiz)? [PMU basics in nutshell] What do I (PMU) do? How am I (PMU) exactly connected to power system network? Can I (PMU) measure current phasor of two different lines? PMU Communication Network Analysis Gelli Ravikumar 3 / 31

4 Key [PMU basics in nutshell] PMU Communication Network Analysis Gelli Ravikumar 4 / 31

5 Gelli s Discussion on 2 papers PMU Communication Network Analysis Gelli Ravikumar 5 / 31

6 Abstract view of papers PMU Communication Network Analysis Gelli Ravikumar 6 / 31

7 Analysis of communication network infrastructure to meet the bandwidth and latency requirements of Power System Applications PMU Communication Network Analysis Gelli Ravikumar 7 / 31

8 Glanse of delay requirements PMU Communication Network Analysis Gelli Ravikumar 8 / 31

9 Types of traffic considered All the Substation (S/S) to Control Center (CC). CC to Control Substation (Generating station and substation having control units like transformers and reactors). Special Protection Scheme (SPS) substation to SPS. Generating substation to Generating substation. SPSs to CC. CC PMUto Communication CC Network Analysis Gelli Ravikumar 9 / 31

10 Inputs and Outcomes PMU Communication Network Analysis Gelli Ravikumar 10 / 31

11 PMU Communication Network Analysis Gelli Ravikumar 11 / 31

12 Methodlogies in nutshell Created simulation scenarios for WAMS applications individually Communication infrastructure is common for all scenarios A hybrid scenario is simulated in which all the applications run simultaneously on the same network infrastructure PMU Communication Network Analysis Gelli Ravikumar 12 / 31

13 Communication infrastructure for the simulation in OMNET 120 PMUs placed in eastern US grid. Two PMUs, relays, and circuit breakers over a 100Mbps Ethernet. PMU Communication Network Analysis Gelli Ravikumar 13 / 31

14 Outcomes PMU Communication Network Analysis Gelli Ravikumar 14 / 31

15 Kedar s Discussion on 2 papers PMU Communication Network Analysis Gelli Ravikumar 15 / 31

16 Purpose of the paper: To provide illustrations on PMU communication networks with a special focus on centralized applications, which envisages and supports the transmission system operators (TSO) while deploying physical PMU communication networks. PMU Communication Network Analysis Gelli Ravikumar 16 / 31

17 Paper Contributions: A brief review on WAMC architectures and its components, and various delays incur to the control center applications is presented. As a case study, an equivalent model of Swedish TSO is considered The model includes geographical distances between PMUs, routers, etc. The model is simulated in OPNET for two scenarios: (i) with and (ii) without considering PDC sorting and timeout concepts. Briefed the PDC timeout concept Lastly, the paper has presented the End-to-End delays of all PMUs and control commands for different channels. PMU Communication Network Analysis Gelli Ravikumar 17 / 31

18 Snapshot of swedish Network TSO The octagons on the map represent subnets (logical grouping of communication networks). The core subnets, core 1 and core 2 represent a network of meshed routers PMU Communication Network Analysis Gelli Ravikumar 18 / 31

19 Result 1:End-to-End delays of all PMUs and control commands for different channels PMU Communication Network Analysis Gelli Ravikumar 19 / 31

20 Time outs in PDC PMU Communication Network Analysis Gelli Ravikumar 20 / 31

21 Result 2: Illustrations of delays and timeouts PMU Communication Network Analysis Gelli Ravikumar 21 / 31

22 Purpose of the paper: To demonstrate the consequence of delayed input data in WAMC systems and the performance requirements this poses on time available for decision making and control actuation. PMU Communication Network Analysis Gelli Ravikumar 22 / 31

23 Paper Contributions: A brief review on the possible delays occur in a complex data transfer is presented In order to detect its maximum tolerated delay, a few simulations are carried out iteratively by importing delayed Phasor measurements to the set up made with Static Var Compensator (SVC). From the simulation results, an analysis on the performance requirements of applications for the centralized computation and control actuation is presented. Moreover, a feasibility study on compensations used in Power System Stablizers (PSS) in situations with much phasor data delay is presented. Lastly, the authors have suggested a ICT architecture for WAMC systems aiming to improve its robustness. PMU Communication Network Analysis Gelli Ravikumar 23 / 31

24 Possible Delays 1. Data propagation time It is the time after full message has been sent from the sender, until it has reached the receiving node. The propagation speed depends on the physical medium of the link (that is, fiber optics, twisted-pair copper wire, etc.) and is in the range of meters/sec for copper wires and for wireless communication. Propagation time = Distance / propagation speed PMU Communication Network Analysis Gelli Ravikumar 24 / 31

25 Possible Delays 2. Transmission time It is the amount of time from the beginning until the end of a message transmission. In the case of a digital message, it is the time from the first bit until the last bit of a message has left the transmitting node. Packet transmission time = Packet size / Bit rate 3. PDC sorting time It is the time required to sort all the received PMU data packets according to the specified configuration. End to End Time delay T ETE = T WAN +Min(Max(T WAN ) T TO ) PMU Communication Network Analysis Gelli Ravikumar 25 / 31

26 The network model (from the famous Kundur book) consists of two fully symmetrical areas that are connected by two parallel 230 kv transmission lines. two identical round rotor generators are located in each area respectively PMU Communication Network Analysis Gelli Ravikumar 26 / 31 Test Bed Implementation Considered network for the test bed is,

27 Remote signal based SVC The goal of the set up is to maintain the voltage stability of the considered network by monitoring the signals speed (ω) and accelerated power (P a ). The rotor speed ω and acceleration power P a are monitored by PMU placed at each generator bus. The data is used to provide a supervisory controlling action on the SVC deployed at a bus. A Static Var Compensator (SVC) controls the reactive power injections in order to maintain good voltage regulation profile. PMU Communication Network Analysis Gelli Ravikumar 27 / 31

28 What happens if delayed phasors are present? Observations: the oscillation grows as the delay increases. When the 69ms time delay reaches: the oscillation can not be controlled even by the SVC. Therefore, for this specific network and WAMC system, the maximum time for the decision making computation and control actuation should be around 21.5ms (assumed value by all the communication network delays is: 47.5 ms). PMU Communication Network Analysis Gelli Ravikumar 28 / 31

29 simulation result with PSS Applied the same simulation scenario with the largest tolerated delay of 69ms. With the power system stabilizer (PSS), the system is stabled with delayed phasors of 69ms. PMU Communication Network Analysis Gelli Ravikumar 29 / 31

30 Future work Generalized methodology to compute latency and bandwidth parameters. PMU Communication Network Analysis Gelli Ravikumar 30 / 31

31 Thank You... Any Queries: PMU Communication Network Analysis Gelli Ravikumar 31 / 31