Manho Joung

Initial review of methods for cascading failure analysis in electric power transmission systems IEEE PES CAMS task force on understanding, prediction, mitigation and restoration of cascading failures

Large blackouts are typically caused by cascading failure propagating through a power system by means of a variety of processes. Because of the wide range of time scales, multiple interacting processes, and the huge number of possible interactions, the simulation and analysis of cascading blackouts is extremely complicated. This paper defines cascading failure for blackouts and gives an initial review of the current understanding, industrial tools, and the challenges and emerging methods of analysis and simulation.

Vulnerability assessment for cascading failures in electric power systems

Cascading failures present severe threats to power grid security, and thus vulnerability assessment of power grids is of significant importance. Focusing on analytic methods, this paper reviews the state of the art of vulnerability assessment methods in the context of cascading failures. These methods are based on steady-state power grid modeling or high-level probabilistic modeling. The impact of emerging technologies including phasor technology, high-performance computing techniques, and visualization techniques on the vulnerability assessment of cascading failures is then addressed, and future research directions are presented.

Sequential Outage Checkers for Analyzing Cascading Outages and Preventing Large Blackouts

This paper presents the use of sequential outage checkers to identify the potential cascading processes that might lead to large blackouts. In order to analyze cascading outages caused by a combination of thermal overloads, low voltages, and under-frequencies following an initial disturbance, sequential outage checkers are proposed. The proposed sequential outage checkers are verified using the AEP 9-bus system, New England 39-bus system, and IEEE 118-bus system.

Strategic Behavior in Electricity Capacity Markets

This paper investigates the ways in which an electricity capacity market design may encourage generators to exaggerate their available capacity. For concrete analysis, a simple two-player discrete game model is introduced, focusing on two pure strategy Nash equilibria: an equilibrium at which generators offer their true capacities, and an equilibrium at which generators offer exaggerated capacities. Consideration of the current capacity market design leads us to conclude that the more conservative the independent system operator’s capacity procurement, the higher the risk of exaggerated capacity offers. We also provide an extended continuous game model, and the analysis shows that when the ISO’s capacity procurement is not conservative enough, the strategic generators will withhold their capacity offers, while, if the ISO’s capacity procurement is too conservative, then the strategic generators will offer more than their true capacity. For illustration, a numerical example is presented.

Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks

This report describes the development of a cascading outage analyzer that, given an initial disturbance on an electric power system, checks for thermal overloads, under-frequency and over-frequency conditions, and under-voltage conditions that would result in removal of elements from the system. The analyzer simulates the successive tripping of elements due to protective actions until a post-event steady state or a system blackout is reached.

Generator Ownership of Financial Transmission Rights and Market Power

Game theory is well suited to analyze a situation with strategic interdependence of multiple decision makers. Electricity markets include both physical and operational attributes. Likewise, electricity markets are characterized by a relatively small number of large market players, limited competitiveness and strategic behavior. Cournot models compete in quantities while Bertrand models compete in prices. Supply function equilibrium function models assume market players compete both in quantity and price. These are realistic assumptions for electricity markets where market players submit a price-quantity schedule. However these models are complex to solve and may not incorporate all technical attributes of electricity markets. Cournot models are easily solvable and yield under reasonable conditions a unique Nash equilibrium. They are also more suitable for short term analysis.