IEEE Sacramento Valley Section

SPEAKERS: Veera (Raju) Vinnakota,  CAISO, Sirajul Chowdhury, CAISO Abstract Ever since Power Markets have been functional in United States and elsewhere in the industry throughout the World State Estimator (SE), an Energy Management System (EMS) Application, had turned into an industry-wide subject for its critical role both for running Electric Power Markets and for Grid Reliability operations in real time. For SE to provide a steady-state power network solution in terms of complex voltages at electrical nodes on the grid in real time, two main inputs are 1. The network that is modeled  and 2. Telemetered real time measurements such as Power flows, voltages and transformer tap settings, equipment CB / switch status. A converged solution provides state of the power network in real time which is essential for other real time applications to provide guidance to the Control room operators so as to be prepared ahead of time or to optimize market operation for real time and Day-Ahead operations. While formulation of State Estimator optimization problem being non-linear in nature, providing a converged solution is the first level of uncertainty, real time or otherwise.  From the point of source where real time telemetered data is originated on the Power grid, such as at sub-stations and generating station, to the computer system on which SE runs in a Control Center, several components working in tandem coupled with uncertainty in availability of measurements to SE in real time pose a great challenge in supporting a reliable SE solution.  Nature of uncertainties in real time include missing a few measurements due to communication errors, loss of a bunch of measurements due to telemetry loss with RTUs, loss of data links impacting real time measurement from several RTUs,  loss of complete data from the whole Balancing Authority participating in Markets and loss of real time data from several BAs due to loss of one or more data links and lastly the loss of computers which serve the data links. Ensuring Market Systems to continue running even during uncertainties in real time measurements, is a challenge and is dealt in this talk. Additionally,  two more aspects which impact SE availability are the tuning efforts which are put in by the support team and the support structure put in place in the organization to have SE get back to solving when it starts failing to provide a converged solution and are discussed. ​Veera (Raju) Vinnakota received his Ph.D. in Electrical Engineering (Power) from Indian Institute of Technology Madras in 1994. He has over 30 years of professional experience out of which over 20 years are in USA, Canada and Belgium in the field of Electric Power Control focusing on Energy Management System ( EMS) Network applications. Raju was an invited professor for about 2 years in establishing a Control Center Laboratory for University of  Liege, Belgium. Raju was with BC Hydro, Canada over 12 years supporting EMS network applications for Control room.  Since 2013 Raju has been working for California ISO engaged in Network Applications’ support for power grid reliability and energy markets. Raju has over 45 research and development publications / presentations in the field of  electric power monitoring and control for real time use, an active contributor in various ways to IEEE Power Engineering Society such as technical presentations, publishing papers, book chapters, panelist, panel chair, chapter chair. His main areas of interest are Power System Security Monitoring and Control for Grid reliability and Energy Markets. Raju is a Senior Member of IEEE, registered Professional Engineer in the province of British Columbia, Canada and is a practicing engineer. Sirajul Chowdhury received his BSEE from the University of Oklahoma in 1990.  He has been working at California ISO as Senior Advisor in EMS Information Technology division. He has been primary lead for Automatic Generation Control and Operator Training Simulator (OTS) including Market Simulation. Sirajul has been the member of many leading teams on the CAISO initiatives energy imbalance market services, reliability coordinator service, integration of renewable energy services, Electric Vehicles into Grid, Demand response implementation. His recent work at ISO involves designing new control logic for demand response, Electric Vehicle into Grid(V2G) project and storage model for regulation. Sirajul has been a leading contributor to various innovative pilot projects related to renewable integration He is a major contributor to the national award for Solar regulation project by National Association of Regulatory Utility Commissioners (NARUC). Sirajul represents Cal ISO in the Performance Work Group (PWG) involving NERC and WECC Standards. Before joining Cal ISO in 1999, Sirajul worked at Landis & Gyr Energy Management Systems supplier for about 10 years, delivering AGC software and EMS around the globe. Sirajul’s interests are in real time systems involving control system design, energy markets, Automatic Generation Control(AGC), Training simulation including Marketing simulation, Load forecast, Reliability Compliance. Presentation Slides

Speakers: Robbie James, PG&E, Scott L. Hayes PE, PG&E Abstract Traveling wave fault location systems have been in use for over half a century, and at PG&E these stand-alone systems have historically been limited to our 500-kV transmission lines for which impedance based fault location has proved difficult on these series compensated lines.  The Transmission System Protection department at PG&E performs hundreds of fault locations every year using traditional impedance based fault location methods.   With the introduction of microprocessor line relays which have traveling wave fault location functionality built in, PG&E has installed several on our lower voltage transmission lines to gain experience with this method and evaluate including this option on all new relay installations.  Lower voltage transmission lines are the most difficult to use impedance based fault locating due to taps, in-feeds and non-homogeneous conductor. The new relays can automatically calculate traveling wave fault locations, but only on clean two terminal lines where the relays on both ends of the line are connected together via a digital communication circuit.  Manual traveling wave fault locating requires a new skill set for the Protection Engineer who at the most basic level needs to understand how traveling waves reflect and transmit through changes in the characteristic impedance along the line.  These changes in characteristic impedance occur at the substation and the point of the fault, but also occur at tap points along the line.  For the double ended traveling wave fault locating method, only accurate determination of the arrival time of the incipient waveform is needed for accurate fault locating, but for the single ended method it is critical to understand these line reflections as manifested in the Bewley lattice diagram.  We will present cases where traveling wave event files on a line with multiple taps could not identify a location and cases where it was successful, and detail the conditions for both results.  Discussion will include the differences between single ended and double ended fault locations with and without GPS clocks.  A comparison between accuracy of our impedance based fault locations and the traveling wave fault locations will be discussed. ​Robert James received his BS in Electrical Engineering and Computer Science from University of California, Berkeley in 2005, and graduated with distinction with an MS in Electrical Engineering from California State University, Fresno in 2009.  He started his career with Pacific Gas and Electric Company in 2008 as an intern in Distribution Engineering and has held his current position as a Transmission System Protection Engineer since 2010.  Robert has been a lead at PG&E for travelling wave fault location on the transmission system.  He is a registered Professional Engineer in the state of California. Scott Hayes received his BS, EEE from California State University, Sacramento in 1985.  He started his career with Pacific Gas and Electric Company in 1984 as an intern.  Since then he has held multiple positions in System Protection including supervisor, as well as Distribution Engineer, Operations Engineer, Supervising Electrical Technician, Supervising Engineer in Power Generation and is currently a Principal Protection Engineer focusing on standards, procedures and quality.  Scott has previously co-authored papers for the Western Protective Relay Conference, Georgia Tech, TechCon Asia Pacific, CEATI Protection and Control Conference and Transmission and Distribution World Magazine. Topics include Thermal Overload Relays for Intertie Lines, Data Mining Relay Event Files to Improve Protection Quality, Effects of CCVT Ferroresonance on protective relays and PG&E’s Wires Down Program.   Scott is a registered Professional Engineer in the state of California and has served as Chairman of the Sacramento Section of the IEEE Power Engineering Society.  He is currently the chairman of the CEATI Protection and Control Program and is a member of the NATF protection core team.  He has also served on a NERC Standard Drafting Team. Presentation Slides

Speaker: Sheikh Zulkader, CAISO Abstract Mr. Sheikh Zulkader from PG&E will share his knowledge and experiences about modern energy management methods in California Independent System Operator. Presentation Slides