This paper discusses historical and technical events in the U.S. and Europe over the last few years that are aimed at modernizing the electric power grid. The U.S. federal government has ratified the "smart grid initiative" as the official policy for modernizing the electricity grid including unprecedented provisions for timely information and control options to consumers and deployment of "smart" technologies. European countries are unified in researching and developing related technologies through various structures supported by the European Union. This paper presents the development of smart grids and an analysis of the methodologies, milestones, and expected evolutions of grid technologies that will transform society in the near future.

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Society's increased concern over green house gas emission and the reduced cost of electric vehicle technologies has increased the number of electric vehicles (EV) and plug-in hybrid vehicles on the road. Previous studies into the effects of electric vehicles on the electric system have focused on transmission, generation, and the loss of life of distribution transformers. This paper focuses specifically on identifying distribution transformers that are most susceptible to excessive loading due to the implementation of electric vehicles. The authors use a binomial probability model to calculate the probability that a specific distribution transformer will experience excessive loading. Variables to the function include the existing peak transformer demand, number of customers connected to the transformer, and the most common EV charger demand. Also included in the paper is an optimization approach that utilizes the results from the binomial function to determine the optimal replacement strategy to minimize replacement costs. An extension of the approach is also utilized to explore the effectiveness of EV targeted demand side management programs. The authors apply the described algorithms to 75 000 distributions transformers within a distribution system located in Denver, Colorado.

The implementation of smart grids will fundamentally change the approach of assessing and mitigating system voltage deficiencies on an electric distribution system. Many distribution companies have historically identified customer level voltage deficiencies utilizing a reactive approach that relies upon customer complaints. The monitoring capabilities of a smart grid will allow utilities to proactively identify events that exceed the voltage threshold limitations set forth by ANSI Std. C84.1 before they become a concern to end-users. This proactive approach can reduce customer complaints and possibly operational costs. This paper describes an approach for determining voltage threshold limits as a function of duration for proactive voltage investigations utilizing smart grid monitoring equipment. The described approach was applied to a smart grid located in Boulder, Colorado. This paper also describes the results of this two-year study.

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