High penetration of converter-interfaced renewable energy resources will significantly change the swing dynamics between synchronous generators (SGs) in future power systems. This article examines the impact of high converter penetration on wave-like disturbance propagation arising from sudden generator and load losses in radial (1-D) and meshed (2-D) power systems. To keep the uniformity assumption as converters are introduced, the rating of each SG is decreased with a converter resource making up for the reduction. Numerical simulations demonstrate that as the penetration level of constant-power grid-following (GFL) converters increases, the speed of disturbance propagation increases due to the reduced system inertia. Naturally, converters with the capabilities to positively respond to disturbances would in turn reduce the propagation speed. Analytical studies based on continuum models are presented for the 2-D system with SGs and constant-power GFL converters in order to visualize the disturbance propagation and validate numerical simulations based on differential-algebraic equations. In addition, fast active power control of converters can slow down the electromechanical wave (EMW) propagation and even contain it. These concepts are illustrated on the idealized radial and meshed systems and a reduced model of the U.S. eastern interconnection.

The use of synchrophasor data for observation and control is expected to enhance the operation and efficiency of the next generation of power transmission systems. The synchrophasor measurement data is usually transferred over public domain networks such as the Internet, thereby making it susceptible to a number of attacks. This paper focuses on packet dropping or gray hole attacks on networks carrying synchrophasor data and develops a mechanism to detect such attacks. Our solutions is based on exploiting the patterns and correlation between packet delays and packet losses due to congestion in order to differentiate naturally occurring packet drops in the Internet from packet drops by gray hole attacks. The effectiveness of the proposed mechanism has been verified using simulations.

System reliability is an integral part of a properly designed deregulated electricity market, even though wholesale energy prices are its most visible piece. This paper discusses the re-sources, collectively known as the ancillary services, in a power system for maintaining reliability. It then discusses an integrated approach in systematically determining and securing the needed ancillary services and system configuration across multiple time spans, culminating in the cooptimization of energy and ancillary services for security-constrained generator unit commitment in the day-ahead market and security-constrained economic dispatch of the generators in real-time operation. The paper also provides a summary of the ancillary services market in several U.S. power markets and proposes several technical issues for further discus-sion and research. Keywords—Ancillary services, deregulated electricity market, multiple settlement system, reliability, security-constrained eco-nomic dispatch (SCED), security-constrained unit commitment (SCUC). I.