Managed by UT-Battelle for the Department of Energy 1 United States Grid Security and Reliability Control in High Load Conditions Presented to Associate Director of the Office of Science Christopher I. G. Lanclos Research Alliance in Math and Science Computation Sciences and Engineering division Dr. Andrew S. Loebl August 13, 2008 Oak Ridge, Tennessee

Managed by UT-Battelle for the Department of Energy 2 Outline  Objectives  Interconnections of the U.S.  Power Through The System  Voltage Change  Impedance and Resistance  Overload Affect on Lines  Physical Aspects of Grid  Timeline: Important Variables Needed for Grid Stability  Conclusion  Acknowledgement

Managed by UT-Battelle for the Department of Energy 3 Objectives Determine variables and mathematic relationships needed to understand electric system and electricity flow and characteristics relative to the 2003 blackout that are need to understand the system Understand basic terms and mathematics need to help protect the system Different mathematical terms and there connected Connection among the important aspects of this particular incident

Managed by UT-Battelle for the Department of Energy 4 Interconnections of the U.S. Electric Power Grid

Managed by UT-Battelle for the Department of Energy 5 Power Through The System  Lack of watt (MW) generated to handle load  The transfer of energy through the different areas affected  P = EI  Power “P” which is measured in watt  Voltage “E” which is measured in volt  Current “I” and is measured in ampere

Managed by UT-Battelle for the Department of Energy 6 Voltage Change  Voltage change and affect on MW and MVar (Volt- Amphere Reactive)  Reactive Power(Var): a unit of the reactive electric power delivered by an alternating current (AC) circuit  E= P/I  E=IR  Resistance “R” which is measured in ohms

Managed by UT-Battelle for the Department of Energy 7 Impedance and Resistance  Z = V/I  Phase-Angles  V = Voltage in volts (V)  I = Current in amps (A)  Z = Impedance in ohms  R = Resistance in ohms

Managed by UT-Battelle for the Department of Energy 8 Overload Affect on Lines  Key lines tripped due to the fact the Zone 3  Impedance relays was not set to handle such a overload.  The cause of Sammis-Star caused an overload so great with some key lines overloaded  Sammis-Star increased the speed of the tripping of lines and the system was not set to react to that kind of disturbance.

Managed by UT-Battelle for the Department of Energy 9 Physical Aspects of Grid  Software  Communication  Mechanics  Equipment management  Importance of measurement

Managed by UT-Battelle for the Department of Energy 10 Timeline: Important Variables Needed for Grid Stability

Managed by UT-Battelle for the Department of Energy 11 Conclusion If major disturbances in the 'grid' are to be prevented in the future, the measures of performance and conditions must be empirically understood, in detail and monitored continuously Anecdotal (post event) After Action Reporting of chronology of events or by summary description such as voltage was degraded or system was unstable is insufficient State Estimator lacks key information resistance, impedance, without which Mvar measures are not actionable (phase angle between voltage and current unknown) Stability reliability are in jeopardy by incomplete data and means of available control to operator Research can be used to inform our electrical power grid operators what kind of understand is need to control and prevent blackouts

Managed by UT-Battelle for the Department of Energy 12 Acknowledgement  The Research Alliance in Math and Science program is sponsored by the Office of Advanced Scientific Computing Research, U.S. Department of Energy.  The work was performed at the Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC under Contract No. De- AC05-00OR This work has been authored by a contractor of the U.S. Government, accordingly, the U.S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes.  Brandon Davis-Alabama A&M University  De’vonte Whitmore-University of Arkansas Pine Bluff  Data and illustrations are from: Technical Analysis of the August 14, 2003 Blackout. North American Electric Reliability Council, Princeton NJ. 13 July 2004